Lawn mower blade rpm. Gas vs Electric Lawn Mowers

US2906081A. Blade speed controller for electric lawn mower. Google Patents

Publication number US2906081A US2906081A US646254A US64625457A US2906081A US 2906081 A US2906081 A US 2906081A US 646254 A US646254 A US 646254A US 64625457 A US64625457 A US 64625457A US 2906081 A US2906081 A US 2906081A Authority US United States Prior art keywords motor speed load switch arm Prior art date 1957-03-15 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired. Lifetime Application number US646254A Inventor Clifford H Flanigan Original Assignee Clifford H Flanigan Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 1957-03-15 Filing date 1957-03-15 Publication date 1959-09-29 1957-03-15 Application filed by Clifford H Flanigan filed Critical Clifford H Flanigan 1957-03-15 Priority to US646254A priority Critical patent/US2906081A/en 1959-09-29 Application granted granted Critical 1959-09-29 Publication of US2906081A publication Critical patent/US2906081A/en 1976-09-29 Anticipated expiration legal-status Critical Status Expired. Lifetime legal-status Critical Current

Links

• 238000001816 cooling Methods 0.000 description 4
• 238000010586 diagram Methods 0.000 description 4
• 239000002184 metal Substances 0.000 description 4
• 240000000218 Cannabis sativa Species 0.000 description 2
• 229920002763 Heavy strand Polymers 0.000 description 2
• 230000003466 anti-cipated Effects 0.000 description 2
• 238000005452 bending Methods 0.000 description 2
• 230000015556 catabolic process Effects 0.000 description 2
• 230000001276 controlling effect Effects 0.000 description 2
• 230000000875 corresponding Effects 0.000 description 2
• 230000004048 modification Effects 0.000 description 2
• 238000006011 modification reaction Methods 0.000 description 2
• 238000010298 pulverizing process Methods 0.000 description 2
• 230000003014 reinforcing Effects 0.000 description 2
• 230000000717 retained Effects 0.000 description 2
• 239000007787 solid Substances 0.000 description 2

Images

Classifications

• A — HUMAN NECESSITIES
• A01 — AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
• A01D — HARVESTING; MOWING
• A01D34/00 — Mowers; Mowing apparatus of harvesters
• A01D34/01 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus
• A01D34/412 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters
• A01D34/63 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters having cutters rotating about a vertical axis
• A01D34/76 — Driving mechanisms for the cutters
• A01D34/78 — Driving mechanisms for the cutters electric

• A — HUMAN NECESSITIES
• A01 — AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
• A01D — HARVESTING; MOWING
• A01D34/00 — Mowers; Mowing apparatus of harvesters
• A01D34/01 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus
• A01D34/412 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters
• A01D34/63 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters having cutters rotating about a vertical axis
• A01D34/67 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters having cutters rotating about a vertical axis hand-guided by a walking operator
• A01D34/68 — Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters having cutters rotating about a vertical axis hand-guided by a walking operator with motor driven cutters or wheels
• A01D34/6806 — Driving mechanisms

Description

BLADE SPEED CONTROLLER FOR ELECTRIC LAWN MOWER Filed March 15, 1957 2 Sheets- Sheet 2 35 FWD 8 42 I 35 INVENTOR j 43 [9 Q CLIFFORD H. FLANIGAN BLADE SPEED CONTROLLER FOR ELECTRIC LAWN MOWER Clifford H. Flanigan, New Albany, Ind.

The present invention relates to electric mowers of the rotating blade type and has particular reference to a novel method of an apparatus for controlling the electric motor drive for the rotating blades. This invention is an improvement on the rotating blade type of electric mower described and claimed in my U.S. Patent #2,643,502, granted June 30, 1953, which disclosure is here incorporated by reference, and is a cOntinuatiOn-in-partof U.S. application, S.N. 373,093, filed August 10, 1953, Patent No. 2,791,876, issued May 14, 1957.

The use of a series wound electric drive motor on this type of mower is desirable for various reasons. However, if the blade structure rotates at a speed high enough to be effective under full load conditions, it will, under progressively lower load conditions, operate at progressively higher speeds and, in the upper portion of its speed range, usually produce an objectionable noise. For example, with a motor producing a blade speed of 5,000 r.p.m. at full load and 10,000 rpm. at no load, the blade noise will become increasingly objectionable at speeds ranging from 7,000 rpm. upwards.

One of the principal objects of this invention is to provide a speed control device for a series wound electric motor using substantial amounts of current, such-as a lawn mower motor, which will satisfactorily limit the speed of the motor below a predetermined value over a load range extending from full load to no load.

Another of the principal objects of this invention is to provide a speed control arrangement for an electric lawn mower which, under load conditions, ranging from full load to no load, limits the speed of the blade to an operating range extending from its normal speed at full load to a higher speed corresponding to its normal speed at a predetermined partial load, the partial load speed preferably being below the objectionable noise range.

Other important objects are: to attain the previous objects by means operating, in response to variations in the ventilating air flow of a fan cooled drive motor, to control I or set the upper limit of the operating blade speed at a predetermined value; and to attain these objects by an automatic switch means which will operate over a long period of time while handling substantial amounts’of electrical current without breakdown caused bythe burning of its contact points.

In constructing a mower for cutting a swath of, say, double width, two blades rotating on separate axes are employed. To drive both blades from a single series wound motor, an expensive, specially constructed heavy 2,906,081 Patented Sept. 29, 1959 they share the load more or less equally under all conditions of operation ranging from a full load on both blades and motors to no load on both and including a partial or full load on one blade with a lower load on the other blade ranging downwardly to no load.

Another important object of this invention is to provide-a multiple electric motor load-sharing drive arrangement with means opertaing, in response to the ventilating air flow variations of at least one motor, to limit the highest operating speeds of both blades to a value Which is relatively unobjectionable from a. noise producing standpoint.

Figure l is acentral sectional view of one embodiment taken on a longitudinal plane passing vertically through the electric drive motor and blade structure but showing both of these parts in elevation;

Figure 2 is a side elevational view on an enlarged scale or a speed controller applied to a drive motor, such as is shown in Figure l, the motor housing being fragmentarily shown in section;

Figure 2a is a top plan view on a reduced scale of the speed controller as it appears in Figure 2, this view showing the bracket rotated a half turn from its Figure 2 position and omitting the motor housing;

Figure 6 is a front elevational view of another embodiment showing an electric mower embodying the loadsharing feature of my invention as well as the speed con trol feature;

Figure 8 is a schematic diagram of the mower of Figure 6, this figure illustratingthe speed control and loadsharing features.

The electric mower shown in Figure 1 is constructed substantially as described in my U.S. Patent No. 2,643,502, granted June 30, 1953. This mower comprises a base plate or chassis 1 supported on wheels’2, and carrying a hollow shaft series wound motor 3 with a rod 4 extending through the hollow shaft 5 of the motor and carrying the cutting blade 6 driven by the motor through a friction clutch connection 7. The motor housing has one or more openings 8 through which air is drawn by a fan fixed on the motor armature for cooling the motor, the air being discharged at the bottom of the motor through suitable openings 9.

The speed controller shown in Figs. 2-5 includes a bracket 10 mounted on the motor housing adjacent one of the openings 8. This bracket preferably is constructed from a sheet metal strip bent into U-shape to provide a bight 11, and a pair of arms 12, 12. One arm 12′ is doubled back at 13 on a biased line disposed at about 45 and then bent outwardly or laterally to provide a shelf 14 on which is mounted a microswitch 15 of the snap-action type.

This type of switch has an operating arm 16 which is resiliently or yieldably urged outwardly from the switch toward the switch-open-position. When the arm 16 is moved a slight distance one way or another, it triggers the switch contact points (not shown) to snap to. an open position or closed position depending upon the direction of arm movement. This closing or opening of the switch contacts is performed at a high speed to keep from developing arcs between them. I have found that a microswitch of this type will operate indefinitely, as a resistance short circuiting switch, under normal current loads of 6 to 12 amperes without burning the switch contact points. This switch is mounted on shelf 14 with its operating arm 16 extending transversely parallel to the body of the switch and projecting therefrom transversely across the adjacent edge of arm 12 of bracket with its projecting end terminating in an inwardly bent tip. The tip is inwardly bent at right angles more or less to extend toward or into the space between bracket arms 12 and 12.

The bracket arms cooperate to carry an axle 17 which is retained against removal, from its position on the bracket, by bending bracket- arm tips 18 and 18 to extend over the ends of the axle 17. A rocker arm 19 made of a strip of sheet metal is positioned with its mid-portion arranged to extend transversely across the space between bracket arms 12 and 12′. This rocker arm 19 has reinforcing flanges 20 and 20′ at its sides. The axle 17 extends through flanges 20, 20 and thus mounts the rocker arm 19 for pivotal movement relatively to bracket 10.

The lower end 21 of the rocker arm is bent relatively to its mid-portion and arranged to carry a counterweight 23 which yieldably urges the lower end of the rocker arm pivotally downward into engagement with a stop 24 on bracket arm 12. This counter weight is adjustably mounted in a slot 25 by a bolt 26 and cooperating nut. The upper end of the rocker arm 19 is bent toward the motor housing to provide an offset vane 27 which extends into the opening 8 of the motor 3 where it is subject to and influenced by the ventilating air that enters the motor housing through opening 8. The tip of the switch arm 16 bears on the rocker arm 19 above the axle 17. The counterweight 23 is suflicient to hold the rocker arm yieldably against stop 24 in the solid line position shown in Fig. 2 during the lower speed and lower air flow ranges of operation of the motor 3. When the rocker arm 19 is in this heavy load or low-speed and low-air flow position, it holds the switch arm 16 in the switch-closed position wherein switch short-circuits a resistance 28 in series with the motor 3.

As the load falls, the speed and air flow rises, the latter ultimately reaching a point where it moves the rocker arm 19 to the switch-open dotted line position shown in Fig. 2. This movement opens the switch 15 and cuts the resistance 28 into the circuit, thus reducing the voltage across the motor. With the voltage reduced, the speed of the motor is reduced. If the load progressively falls off to no-load, the speed will be readily held below the objectionable noise range by using a resistance of appropriate value.

In operation, I assume: that a series wound 110115 volt motor, operating between 5,000 and 10,00012,000 r.p.m. under full load and no-load conditions respectively, is employed; that the noise of the cutting blade begins to be objectionable at speeds ranging from 7,000 r.p.m. upwardly; and that the rocker arm 19 is counterweighted so that it will operate in the neighborhood of 5,500 to 5,800 r.p.m. Under full-load conditions, the counterweight will hold the switch in the closed position. When the load decreases enough to allow the speed to rise to 5,800 r.p.m., the air flow will have become sufficient to move the rocker arm 19 inwardly, in r ‘on to the motor housing, to the extent required to al ow’the switch arm 16 to move to the switch-open position. This will reduce the speed to a value, say approximating 5,500, and, at the same time, reduce the.rrent flow from, say, 10 amperes to 6 amperes. But t is raction in speed and current will not necessarily cause i switch to reclose without a further reduction in speed.

If the load continues to fall off, the speed will con tinue to increase but the increase is less substantial now,

with the resistance in the circuit, than it would be with the resistance short circuited. With a proper resistance in the circuit, the no-load speed will be less than 7,000 r.p.m. The setting of the speed controller may be varied but, under most conditions of operation, it is preferably set to operate in the.85% load range. In other words, it should operate at a speed substantially below that at which the noise becomes objectionable and substantially above the full-load operating speed.

Under certain conditions of operation, where higher blade speeds are desired, as is the case in pulverizing leaves or in cutting heavy strands of thick grass, the setting may be varied to a higher value either by using a smaller weight 23 or shifting the counterweight in the slot 25 to reduce its distance from the fulcrum shaft 17.

Also, under certain operating conditions, the operator may desire to keep the switch 15 in either a closed or an open position regardless of the speed of the motor 3. This may be done by moving the control arm 29 to either of its extreme positions from the middle position shown in Fig.2 which allows the rocker arm 19 to operate the switch in the normal manner. The control arm 29 is pivotally mounted on a pivot pin 30 fixed to an upstanding bracket 31 which in turn is fixed to the lawn mower chassis 1. One end of the arm 29 includes a bifurcated portion having upper and lower legs 32 and 32′ extending over and under the lower end 21 of the rocker arm 19. These legs are spaced sufficiently so that when arm 29 is in its middle position, the legs will not interfere with the normal movement of the rocker arm 19, but when the arm 29 is in either of its extreme positions, one leg or the other will engage the rocker arm and hold it in either a switch open or a switch closed position. The arm 29 also includes a detent (on the rear side of the arm in Fig. 2) adapted to be selectively engaged in appropriate detent holes 33 in the bracket 31 to hold the arm 29 in any of its three positions.

In the embodiment shown in Figs. 6 to 8, the frame of the mower supports two motors 35, 35 which may be.115 volt motors substantially like motor 3. Each of these motors carries a cutter blade 6 mounted on the motor shafts 36 and 36′ as before. One of these motors, say motor 35, preferably is equipped with the abovedescribed speed controller. The motor shafts 36 and 36′ carry V pulleys 37, 37, respectively, and a V belt 38 extends around these pulleys. This arrangement compels the motors to operate at the same speed and to share the load. A resistor 39 is mounted on a bracket 40 on the chassis.

A 220-230 volt circuit for operating the motors, is shown in Fig. 8. It places the motors 35 and 35 and the speed controller all in series. Accordingly, current flows from power line 41, lead line 42, motor 35, connecting line 43, motor 35, line 44, the speed controller, and line 45 to power line 46. With this arrangement, both motors will share the load more or less equally at all times.

Where both cutting blades are operating under the same load conditions, each motor will drive its own blades more or less independently of the other. However, where one blade operates under a lighter load condition than the other blade, the motor of the lightly loaded blade will tend to increase its speed. In doing this, it simply tends to drive the belt 38, connecting it to the other motor, at a higher rate of speed and, as a result, takes some of the load from the heavily loaded motor, the ultimate division of the load being substantially equal. Where the speedof both motors tends to rise above the predetermined-value at which rocker arm 19 operates, that arm will operate ‘to open the switch 15 and place the resistor 39 in series withboth motors and thus limit the upper speed range as before.

Why I Switched BACK to a Gas Lawn Mower

The advantage’of the speed control arrangement resides in the fact that it facilitates the operation of the lawr’i mower under all load conditions without producing an objectionable noise. In this connection, it will be appreciated that the capacity or power of the drive motor is reduced by the speed controller only in the lighter load ranges where a reduction in work capacity can be afforded.

It is anticipated that a modification of the described speed control arrangement may utilize a centrifugal force responsive means rotating With the motor shaft in place of the air flow responsive vane for operating the snapaction switch between open and closed positions.

An electric lawn mower comprising: an electric series-wound motor having a housing, a vertically arranged drive shaft therein and a cutter on the lower end portion of said shaft, said housing having vent openings; a motor-cooling fan located within said housing and mounted on said shaft for flowing air through said vent openings at a speed which increases and decreases with the motor speed; an electric circuit operatively connected to said motor, said circuit including a resistor, a bypass around said resistor and a switch for opening and closing said bypass; and operating means for opening and closing said bypass respectively as the motor speed rises beyond the high limit of a low motor speed range and falls below the low limit of a high motor speed range, said high limit being of a higher value than said low limit, said means including a vane, means movably mounting said vane adjacent one of said vent openings in position to be operated in one direction by the air current passing through the one opening, opposing means yieldably urging said vane in the opposite direction, and

means operatively interconnecting said operating means and said switch for closing said bypass when the speed of said motor is reduced due to the imposition of a heavy load on said cutter.

The mower of claim 1 wherein: said opposing means includes a counterweight biasing said vane in said opposite direction.

The mower of claim 1 including: means selectively operable to hold said switch in one of its positions regardless of the speed of said motor.

The mower of claim 1 including: a mobile lawn mower frame; said motor being mounted on said frame; a second electric series-wound motor mounted on said frame and having a second vertical drive shaft carrying a cutter on its lower end portion; said electric circuit operatively connecting said second motor in series with said first-mentioned motor; and power transmitting means mechanically interconnecting the shafts of both of said motors to compel both motors to share the total load and to operate at coordinated speeds.

References Cited in the file of this patent UNITED STATES PATENTS 2,144,734 Jepson Jan. 24, 1939 2,425,178 Eilerbeck Aug. 5, 1947 2,643,502 Flanigan June 30, 1953 2,791,876 Flanigan May 14, 1957

US646254A 1957-03-15 1957-03-15 Blade speed controller for electric lawn mower Expired. Lifetime US2906081A ( en )

Priority Applications (1)

Application Number Priority Date Filing Date Title

US646254A US2906081A ( en )	1957-03-15	1957-03-15	Blade speed controller for electric lawn mower

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title

US646254A US2906081A ( en )	1957-03-15	1957-03-15	Blade speed controller for electric lawn mower

Family Applications (1)

Application Number Title Priority Date Filing Date

US646254A Expired. Lifetime US2906081A ( en )	1957-03-15	1957-03-15	Blade speed controller for electric lawn mower

Cited By (9)

Cited by examiner, † Cited by third party

Publication number Priority date Publication date Assignee Title

DE1151970B ( en )	1959-11-25	1963-07-25	Wolf Geraete Gmbh	Lawn mower with electric drive
FR2151894A5 ( en )	1971-08-31	1973-04-20	Deere Co
US4333302A ( en )	1981-03-13	1982-06-08	Ronald Thomas	Combined A.C./D.C. electric lawn mower
US20080284363A1 ( en )	2006-10-17	2008-11-20	Lucas Delbert E	Hybrid electric cleaning device
US7479754B2 ( en )	2006-10-17	2009-01-20	Desa IP Llc	Hybrid electric lawnmower
US7728534B2 ( en )	2006-10-17	2010-06-01	Mtd Products Inc	Hybrid electric lawnmower
US8076873B1 ( en )	2007-06-01	2011-12-13	Mtd Products Inc	Hybrid outdoor power equipment
US20140137527A1 ( en )	2011-07-12	2014-05-22	Yanmar Co., Ltd.	Mobile Electric Work Machine
US9787225B2 ( en )	2006-10-17	2017-10-10	Mtd Products Inc	Hybrid electric device

Patent Citations (4)

Cited by examiner, † Cited by third party

Publication number Priority date Publication date Assignee Title

US2144734A ( en )	1936-09-03	1939-01-24	Chicago Flexible Shaft Co	Combined motor and speed control device
US2425178A ( en )	1943-11-27	1947-08-05	Friden Calculating Machine Co	Motor control
US2643502A ( en )	1949-07-05	1953-06-30	Clifford H Flanigan	Power lawn mower of the rotating cutting disk type
US2791876A ( en )	1953-08-10	1957-05-14	Clifford H Flanigan	Drive means for multiple rotating disc type lawn mower

Cited By (11)

Cited by examiner, † Cited by third party

Publication number Priority date Publication date Assignee Title

DE1151970B ( en )	1959-11-25	1963-07-25	Wolf Geraete Gmbh	Lawn mower with electric drive
FR2151894A5 ( en )	1971-08-31	1973-04-20	Deere Co
US4333302A ( en )	1981-03-13	1982-06-08	Ronald Thomas	Combined A.C./D.C. electric lawn mower
US20080284363A1 ( en )	2006-10-17	2008-11-20	Lucas Delbert E	Hybrid electric cleaning device
US7479754B2 ( en )	2006-10-17	2009-01-20	Desa IP Llc	Hybrid electric lawnmower
US7482768B2 ( en )	2006-10-17	2009-01-27	Desa Ip, Llc	Hybrid electric lawnmower having dual power supply
US7728534B2 ( en )	2006-10-17	2010-06-01	Mtd Products Inc	Hybrid electric lawnmower
US8732896B2 ( en )	2006-10-17	2014-05-27	Mtd Products Inc	Hybrid electric cleaning device
US9787225B2 ( en )	2006-10-17	2017-10-10	Mtd Products Inc	Hybrid electric device
US8076873B1 ( en )	2007-06-01	2011-12-13	Mtd Products Inc	Hybrid outdoor power equipment
US20140137527A1 ( en )	2011-07-12	2014-05-22	Yanmar Co., Ltd.	Mobile Electric Work Machine

Similar Documents

Publication Publication Date Title

US2906081A ( en )	1959-09-29	Blade speed controller for electric lawn mower
US3895481A ( en )	1975-07-22	Lawn mowers
US2253170A ( en )	1941-08-19	Door operating mechanism
US5708333A ( en )	1998-01-13	Series-wound motor with a braking element
US2733396A ( en )	1956-01-31	Luthxr
US2791876A ( en )	1957-05-14	Drive means for multiple rotating disc type lawn mower
US4434692A ( en )	1984-03-06	Grid-type bread-slicing machine
US3914673A ( en )	1975-10-21	Structural speed control for electric motors
US3381197A ( en )	1968-04-30	Motor speed responsive arrangement for controlling motor winding circuits
US2475276A ( en )	1949-07-05	Brush lifting mechanism
US3209093A ( en )	1965-09-28	Lever operated switch actuated by a speed responsive mechanism of a dynamoelectric machine
US2570222A ( en )	1951-10-09	Electric motor
US2773441A ( en )	1956-12-11	Control for power-operated toaster
US2483122A ( en )	1949-09-27	Circuit controlling device
US2623961A ( en )	1952-12-30	Speed control for motors
US1828016A ( en )	1931-10-20	Automatic kitchen ventilator
US2930597A ( en )	1960-03-29	Electric food mixer and speed control mechanism
US2872540A ( en )	1959-02-03	Governor switch
US3456180A ( en )	1969-07-15	Motor speed control
US2671192A ( en )	1954-03-02	Circuit breaking switch for small electric motors
US2739552A ( en )	1956-03-27	Motor drives for sewing machines
US2703381A ( en )	1955-03-01	Speed control mechanism
US3293388A ( en )	1966-12-20	Plunger operated switch unit for use in a dynamoelectric machine
CN110244220A ( en )	2019-09-17	Microswitch life test control device
US3424964A ( en )	1969-01-28	Overload warning signal for motors

Gas vs Electric Lawn Mowers

You might be wondering: are electric lawn mowers better than gas? Let’s dive in and find out which is a better fit for your lifestyle and your yard. It’s no surprise which side of the fence we’re on here at Greenworks – and we’re excited to weigh in on the great lawn mower gas versus battery-powered debate.

Difference Between Battery vs. Gas Mowers

The power story has long favored gas-powered lawn mowers, but a battery-powered evolution has taken over in recent years. Electric motors can match the same blade speed and cut quality as gas mowers – without the harmful emissions, high maintenance costs or lost efficiency associated with gas mowers. Thanks to innovative technology, battery-powered lawnmowers produce a more consistent cut quality than gas by maintaining constant blade tip speed. Did you know that the technology that goes into a battery-powered motor mower is completely different from a gas-engine lawn mower? We’re used to thinking that horsepower is the key measurement of lawn mowing performance – but horsepower doesn’t tell the whole story of lawn mower power.

All lawn mowers, both gas and electric, are fueled by a power source. The differences lie in the fuel type and how the energy transfers to make the motor run.

GAS-BURNING MOWERS c ombine a mixture of air and gas that is ignited with a spark to create a mini explosion – which is then harnessed to power the mower. These mini-explosions can result in sparks, which is especially dangerous in dry, wildfire-prone areas of the country. ELECTRIC LAW MOWERS with brushless motors utilize magnets (or carbon brushes) and electromagnets instead of relying on sparks and gas. The magnets interact and energize metal coils that move the rotor. This mechanism is powered by electricity provided by batteries, or in some cases, a cord plugged into a power source. BATTERY-POWERED MOWERS with brushless motors like Greenworks use the placement of the electromagnets to eliminate the need for carbon brushes. creating an even more powerful, efficient and long-lasting motor. You read that right: a battery-powered lawn mower runs on magnets. It’s power-packed and sustainable!

Brushless Motors Smart-Sensing Microchips

The superior performance of a Greenworks battery-powered lawn mower comes from the brushless motor – aided by Smart-sensing microchips that efficiently use the available battery power. When you hit tall, wet or thick grass, an electric mower senses the resistance, draws more power and increases the blade speed to ensure a clean, consistent cut. Our innovative technology makes battery-powered lawn mowers less likely to bog down than gas-powered mowers. Most of the time – especially in regularly maintained yards – the extra power is unnecessary. When less power is needed, the microchip sensors help to conserve energy, extending your electric mower’s runtime and productivity.

Blade Speed Cut Quality

Blade speed and cut quality are more accurate indicators of lawn mower performance. After all, the end goal is to get the job done well and with energy to spare. Brushless motors can maintain a high blade speed when needed. For example, a Greenworks lawn mower with SmartCut technology maintains a constant blade tip speed to ensure a clean cut. Many electric lawn mower models also have a turbo button for tricky grass sections that need an extra power boost.

How Long Do Battery-Powered Electric Lawn Mowers Last?

• Amount of power : Thick or tall grass will require the motor to draw more power from the battery.
• Brushless motor vs brushed : Brushless motors are significantly more efficient so you can mow longer.
• Watt hours (Battery Voltage x Amp hours): Higher wattage indicates more available power giving longer battery life.
• Grass conditions: Depending on what part of the country you live in, the type of grass (as well as how thick or wet it is) can pull more battery power.

It’s a common misconception that gas mowers have longer run times – but the reality is that for larger yards, you’ll still need to refuel mid-mow. It’s similar with battery-powered lawn mowers – you might need to swap in a fresh battery to extend your runtime, but that’s a simple and hassle-free fix.

Benefits of an Electric Lawn Mower

Why make life more complicated than it needs to be? Cordless lawn mowers are so easy to use – and easy on your wallet, too. Check out some of the perks of mowing with a battery-powered lawn mower:

• Effortless: Electric lawn mowers are lightweight for easy maneuverability – meaning less vibration and fatigue.
• Push button start: No more wrestling with gas mowers pull cords to fire up your gas mower. With an electric lawn mower, the easy push-button start will make operation smooth and effortless.
• Less noise: Everyone has a neighbor with a noisy gas-guzzling lawn mower. Become the new MVP of your neighborhood with an electric mower – you’ll notice it’s significantly quieter and typically stays below noise pollution guidelines.
• Maintenance: Electric lawn mowers require fewer maintenance costs – no oil changes, air filters, belts, carburetors or spark plugs to replace. Say goodbye to those costly lawn mower tune-ups every spring – with electric mowers, charge your batteries and you’re ready to mow.
• Skip the fuel: Avoid high fueling costs (and gas spillages – your driveway will thank you!) each time your lawn needs a trim.

Electric vs. Gas Lawn Mower Costs

It’s true – there are some clear advantages to electric lawn mowers. But let’s get down to the question on everyone’s mind: what’s the cost difference between gas versus electric mowers?

While some electric models might be more expensive in the initial purchase price, the long-term cost savings are significant. At Greenworks, we’ve done the breakdown for you. Here’s an example of anticipated cost savings between a battery-powered and gas lawn mower – what starts as a higher initial cost has a significantly lower lifetime cost, so don’t be afraid to play the long game when choosing your next lawn mower.

Operating and Maintenance Costs

So you’re all in on the battery-powered mower technology – but what about the maintenance?

It’s a myth that battery-powered tools are more expensive than gas – especially for electric riding and zero-turn mowers. The initial cost might be higher, but keep in mind a few key factors on long-term cost:

• Zero gas: No filling up with (pricey!) gas each time you mow (1-2x a week for 6 months).

• Zero maintenance: You’ll never have to put gas in it – or change the oil, replace a belt or worry about whether or not it will start after the offseason.

• Zero inconveniences : No more priming the engine, wrestling with difficult pull cords or scheduling tune-ups and repairs.

Battery-Powered Lawn Mowers For the Win

Is a landline better than a smartphone? At one point in time, no one could imagine a world without a landline – and now we can’t imagine even an hour without our trusty smartphones nearby. It’s the same with battery-powered technology. The ease, performance and convenience of battery-powered lawn equipment have helped Greenworks emerge as a game-changer in the electric lawn mower industry. You’re no longer stuck with noisy, gas-guzzling lawn mowers of the past – there are cleaner, faster and more efficient mower options. And with battery-powered mowers coming in push, self-propelled, tractor and zero-turn models, there is a Greenworks lawn mower to fit every yard and every lifestyle.

Ryobi Smart Trek 20″ Self-Propelled Lawn Mower Review

The Ryobi Smart Trek 20 self-propelled lawn mower does its best work if you generally keep up with your grass height consistently and place a heavy priority on bang for your buck and low noise. If that’s you and your house sits on a lot up to 1/3 of an acre, pull the trigger. Grab an extra battery to confidently cover 1/2 an acre.

Ryobi Smart Trek 20″ Lawn Mower Highlighted by Value and Quiet Operation

We tested 24 mowers for a head-to-head comparison recently, looking at both gas-powered and battery-powered models. We even considered commercial mowers and mowers geared more toward homeowners. Ryobi sent 2 versions of their latest mower. Today’s muse if the Ryobi Smart Trek 20″ self-propelled lawn mower. There’s also a 21″ version that you can read about here.

Pros

• Single-point height adjustment
• Quiet operation at 80 dB(A)
• Efficient battery use
• High value score (449 kit with 6.0Ah battery)

Cons

• Self-propelled drive takes time to adjust to
• Competent to cut, but less power than some of its competition

Shootout Results

The Ryobi Smart Trek 20″ self-propelled lawn mower does its best work if you generally keep up with your grass height consistently and place a heavy priority on bang for your buck and low noise. If that’s you and your house sits on a lot up to 1/3 of an acre, pull the trigger. Grab an extra battery to confidently cover 1/2 an acre.

We’re curious to see more feedback on the Smart Trek system and if Ryobi decides to make any adjustments to it moving forward. As the highlight feature for two of their battery-powered lawn mowers, it’s a big change from traditional drive systems that takes time to adjust to.

Battery-Powered Self-Propelled Lawn Mower Ranking: 9th Place

Performance

We use a complex variety of testing methods and data analysis to come up with our mower rankings, but we don’t necessarily want to bore you with the ins and outs of all that here. However, if that’s the sort of thing that gets you up in the morning, feel free to check out our cordless mower shootout!

Cutting Speed

Maintaining a fast blade tip speed is important for a mower since it ensures that it will provide the suction to pull the grass up into the deck and the power to actually cut.

We first measured the no-load speed of each mower to get a good baseline reading of what each one was capable of. This Ryobi Smart Trek 20″ self-propelled lawn mower clocked in at 2574 RPM with the blade tips hitting 145.4 MPH. This was the slowest no-load speed that we saw from our self-propelled battery-powered mowers.

Electric Lawn Mower vs Gas Lawn Mower Review

With brushless motors, we expect an increase in speed as the mower encounters resistance. As the job gets tougher, a brushless motor’s electronics will direct more power to the blades to keep up with the work.

So, we hooked each mower up to our light-duty simulation – a test designed to replicate the conditions of a weekly maintenance cut. The Ryobi Smart Trek 20″ lawn mower actually dropped a bit of speed here. It only cranked out 2521 RPM with 142.4 MPH on the blade tips. That keeps it in last place at this point.

We then put our mowers through our heavy-duty testing, increasing the load we put on the blade. While we did see an increase of 19.5 MPH, this Ryobi model still finished in the last position with 2867 RPM and 162 MPH blade tip speed.

Takeaway

3000 RPM is the kind of rotation speed we like to see when we’re cutting to get the best mulching and bagging characteristics. However, that’s roughly 160 – 190 MPH a the blade tips depending on the blade diameter and Ryobi does hit the bottom of that range.

The trade-off here is that the lower speeds give you more efficient use of your battery while leaving a cut that isn’t as clean as models with higher speed and lift.

Cutting Area

Another important aspect of a battery-powered mower revolves around its runtime and power management. With a gas mower, you can just drop some more fuel into the tank and go. But with battery power, you get a nice long break if you run out of juice and don’t have a back-up battery charged up. Getting the most cutting area out of your battery is a big deal.

Under maintenance-cut conditions, we got 48 minutes worth of runtime from the Ryobi Smart Trek 20″ self-propelled lawn mower’s 6.0Ah battery. With its 19″ blade (yes, this “20-inch” mower uses a 19″ blade) and 48 minutes of runtime while walking at a constant 2.5 MPH, you can clear up to 16,720 square feet on a charge. To put in terms that are a little more concrete, that’s about 0.38 acres.

From a runtime perspective, it’s not bad at all. We like to see around 45 minutes at a minimum unless you’re maintaining a small city lot. Ryobi gives you plenty of maintenance cutting time for lawns up to 1/3 acre or so. You can easily do 1/2 an acre by adding a second battery.

Battery Efficiency

How efficient is Ryobi’s battery use? With its 40V, 6.0Ah battery, we’re looking at a grand total of 216 watt-hours. Under no-load, the Ryobi runs for 56 minutes, while under a light load, it runs for 48. This is 85.7% of the no-load speed, which is actually the highest percentage we saw.

Keeping in mind that its blade speeds were also the slowest on a maintenance cut, it’s clearly prioritizing efficiency.

With 16,720 square feet of cutting on a charge, we see that this mower gets 77 square feet mowed per watt-hour.

The end result? The Ryobi Smart Trek 20″ lawn mower finished our efficiency testing as the 2nd-place finisher behind the Greenworks Commercial model and virtually tied with Kobalt’s 80V.

Noise Level

With gas power, we just assume every mower will be loud (which is almost universally true, save for the Honda HRC216 mower we tested). Battery-powered mowers have the benefit of being a whole lot quieter to run, so we think it’s worth the comparison.

This Ryobi self-propelled lawn mower cranked out just 80 dB(A), which was good enough for a 5th-place finish in our shootout and just 2 decibels out of first place. In any case, your neighbors will appreciate your choice to go with the Ryobi if you’re getting to work early on Saturday morning.

Feature Set

Smart-Trek Drive

We like the idea of Ryobi’s Smart Trek drive, but it is a change that takes time to get used to. It works like this: as you walk forward, you sort of naturally press in on the spring-loaded handle. This is your throttle – the faster you walk, the more you’re pressing in on the handle and the faster the mower drives forward.

The struggle is that the drive kind of jumps forward or brakes hard. There’s no real easy transition from slow to fast or fast to slow, and the movement feels jerky. By bending your elbows, you learn to kind of roll with the changes the same way a mountain biker or skier tackles a course. There’s definitely an adjustment period, though.

Deck Material

We understand why some teams use plastic poly for the mower deck – generally, it drops some weight from the mower and makes it easier to push around. But we prefer steel for its durability. The Ryobi 20″ Smart Trek self-propelled lawn mower opts goes the plastic route.

Height Adjustment and Range

We really like the height adjustment design on this Ryobi Smart Trek lawn mower. It’s a single-point adjustment, but where other single-point adjustments can still require you to lift up while you adjust, this one really can be set one-handed without having to wrestle with it.

It has 7 available positions ranging from 1.75″ to 4.5″. There are some instances where you might like to get a bit lower on the bottom end of the range, but this mower will tackle the vast majority of grass types you’ll come across.

Handle Positions

Rather than having two or three set positions to set your handle, you can actually slide the handle to a position that feels most comfortable for you. #win.

Discharge Options

Out of the box, you can bag or mulch with the Ryobi 20″ Smart Trek self-propelled lawn mower, suiting the majority of situations. If you prefer the side discharge option, Ryobi offers the accessory separately.

Value

With a 6.0Ah battery and charger, the Ryobi RY40LM30 kit runs 449 at Home Depot. It comes with a 5-year warranty on the mower as well. It scores well for value, thanks to a budget-friendly price to go with its adequate performance.

One of the reasons we like Ryobi tools so much is just because of the incredibly deep line they have. The 40V line doesn’t have the same depth as their One 18V line, but there’s still a lot to choose from. Ryobi has string trimmers, blowers, leaf vacs, snowblowers, cultivators, mowers, chainsaws, sprayers, hedge trimmers, pole saws, and a multi-head power system available on the 40V platform.

The Bottom Line

The Ryobi Smart Trek 20″k self-propelled lawn mower does its best work if you generally keep up with your grass height consistently and place a heavy priority on bang for your buck and low noise. If that’s you and your house sits on a lot up to 1/3 of an acre, pull the trigger. Grab an extra battery to confidently cover 1/2 an acre.

We’re curious to see more feedback on the Smart Trek system and if Ryobi decides to make any adjustments to it moving forward. As the highlight feature for two of their battery-powered lawn mowers, it’s a big change from traditional drive systems that takes time to adjust to.

Ryobi Smart Trek 20″ Self-Propelled Lawn Mower Specs

For more information about Ryobi’s 40V lineup, check it out by clicking here.

The Best Zero-Turn Mowers of 2023

These achieve the rare feat of making lawn mowing fun.

By Roy Berendsohn Published: Mar 1, 2023

When it comes to yard work, zero turn mowers do the impossible. They make lawn mowing fun. They accomplish this by putting unprecedented speed, control and maneuverability at the disposal of the person mowing the lawn. The so-called “zero turn” feature of these mowers converts a grass cutting machine into something akin to an amusement park ride. You steer the machine with two levers—the left lever controls the left wheel, the right lever the right wheel. With that steering setup, you can zoom over the landscape cutting straight lines, curves, or pivot the mower into and out of a corner. What’s not to like?

Read on to understand how these agile grass cutters work, how we go about testing them, and see some candidates that we’ve recently tested as well as some that we haven’t but that we think look particularly promising.

How Zero-Turn Mowers Work

A zero-turn riding mower consists of an operator platform, a frame and wheels, an engine (or battery bank), transmissions (or motors), and a pair of control levers commonly known as lap bars. In gas mowers, the engine powers a pulley system. One group of pulleys drives the blades, another group powers a pair of transmissions–one at each rear wheel. When you move the lap bar forward or back, you are directing the transmission to go faster, slower, or even turn the opposite way. When one drive wheel turns clockwise and the other counter clockwise, the mower pivots. When the wheels rotate at different rates, the mower turns in an arc-shaped path. When the lap bars are in the neutral position, the mower stops. Aside from a parking brake, there’s no other braking mechanism. Battery-powered zero-turn mowers work the same way, but have separate motors to drive the rear wheels and one for each blade inside the mower deck.

When it comes to transmission, most mowers have a Hydrogear EZT—a well-known and cost-effective residential-grade transaxle with a reputation for durability.

Some mowers use a deck stamped from one piece of steel, others use a deck fabricated from multiple pieces and welded together. A fabricated deck can be built from thicker steel at a lower cost than it would be able to be built otherwise. Once you’re talking about stamping metal as thick as 10 gauge (about 1⁄8 inch thick), the cost of stamping such a deck would push up the mower’s price beyond what most people are willing to pay. The decks in the mowers below range from 42 to 52 inches, a typical size in this class of product. When powered by these engines and the Hydrogear, these mowers will deliver a decent cut quality at their rated top speed of 7 mph. Note, however, that cut quality declines steeply if you maintain that speed in very thick grass or on uneven terrain.

As to the electric mowers, they represent the leading edge of the technology in this category. These are remarkable and expensive mowers powered by large-voltage lithium-ion batteries. If you’re interested in reducing mowing noise and simplifying your maintenance routine by eliminating gas and oil, they’re worth a look.

Selecting a Zero-Turn Mower

Everyone would like to select the biggest possible zero-turn mower with the hope of whittling a big grass cutting job down to size as quickly as possible. Reality usually intercedes because these machines are expensive and the wide range of options available today quickly drive up the cost. Roughly speaking, you start somewhere in the range of a mower with a 42-inch deck costing in the vicinity of 3200 to 3500 and move up in increments of 1000 to 1500 until you reach entry-level commercial-grade equipment that costs 7000 to 8000.

Again, speaking in terms of approximation, a mower with a 42-inch deck will cut a two-acre lot (that takes into account that the house, driveway, outbuildings and various landscape features are taking up some of that space). Use a mower with a larger deck to cut anything over two acres. But here’s the caveat. That entry-level ZTR mower (3200, say) with a 42-inch deck will wear out faster and need more maintenance than a mower with a 50-inch deck, a heavier frame, larger engine and higher quality transmissions, and thicker deck with more robust blade spindles, costing 4500.

In the simplest possible terms, you can cut a smaller area with a larger mower and expect more longevity out of the machine (not to mention a nicer mowing experience) or you can cut a larger area with a smaller machine and encounter more maintenance and a mowing experience that will be, we might say, a bit more rugged.

But there are still other factors to consider, in selecting a mower other than deck size and your budget. Larger mowers take more space in a garage or outbuilding. And a mower with a 50-inch or even 60-inch deck, as useful as it might be in getting the job done more quickly, may not fit through a fence’s gate, and it might be more difficult to maneuver in tight spots without creating scalp marks on the lawn from a lot of close-quarter pivoting.

Carefully consider all these factors when shopping for a mower: your budget, maintenance and whether you will perform that work yourself, mowing speed and time, maneuverability and trimming in tight areas, the importance that you place on your comfort while mowing, cut quality, longevity, storage, and access to the landscape.

How We Select and Test

There’s only one way to test a mower, and that’s to cut grass with it. But we also do more than mow.

We raise and lower the deck and adjust the seat. We look at service point access (the air filter, the spark plug, and the oil filter) and how easy it is to remove the deck. We mow approximately an acre with each mower, considering cut and mulching quality while running uphill, downhill, across washboard, and along sidehills. (On sidehills, we’ll mow surfaces pitched up to approximately 20 degrees; manufacturers generally recommend not going steeper than 10 degrees, but we like to be thorough.) We evaluate power and speed relative to cut quality—we investigate whether the mower delivers a decent cut mowing at full speed. When mowing in damp conditions, we look at whether the mower’s tires accumulate grass and how effectively it discharges moist clippings. Finally, we test maneuverability (these machines are, generally, very nimble) and how readily they come to a stop when you back off the lap bar control levers.