Mower with Hybrid Prime Mover Having Fuel Cell, Brushless Electric Motors for Driving Cutting Units, and Electric/Hydraulic Actuator for Lift and Lower System

• US 20080289309A1
• Filed: 02/08/2006
• Published: 11/27/2008
• Est. Priority Date: 02/09/2005
• Status: Abandoned Application

• Current Assignee: Jackie R. Gust, Mark S. Anderson
• Original Assignee: Jackie R. Gust, Mark S. Anderson
• Inventors: Gust, Jackie R., Anderson, Mark S.
• Application Number:
  US11/883,978
• Publication Number:
  US 20080289309A1
• Time in Patent Office: Days
• US Class Current: 56/11.9
• CPC Class Codes: A01D 69/00 Driving mechanisms or parts thereof for harvesters or mowers driving mechanisms for the cutters of mowers or harvesters A01D34/00
• CPC Class Codes: A01D 69/025 Electric hybrid systems

Abstract

This invention relates to a hybrid lawn mower powered by a fuel cell and an electrical storage system, both of which supply electric power to the drive wheels and cutting units of the mower. The electrical storage system comprises an ultracapacitor pack or a battery pack. The electric motor driving each cutting unit comprises a brushless motor having an integrated gear reduction stage. In addition, the motor includes an integrated electronics housing in which the electronics for controlling and powering the motor are packaged. The cutting units are lifted out of engagement with the ground by a lift and lower system comprising an electric/hydraulic actuator that is driven only during lifting of the cutting units. The cutting units are lowered by releasing fluid pressure in the lift and lower system and permitting the force of gravity to lower the cutting units.

Claims

1. An electrically driven turf maintenance machine, which comprises:

(a) a frame;

(b) a plurality of ground engaging wheels attached to the frame for supporting the frame for movement over the ground;

(c) at least one electric motor operatively connected to at least one of the ground engaging wheels for propelling the wheel to provide traction for the frame;

(d) at least one operating unit carried on the frame for performing a turf maintenance operation;

(e) at least one electric motor operatively connected to at least one operating unit for powering the operating unit; and

(f) an electric drive system carried on the frame for providing electric power to the electric motors, the electric drive system comprising;

(i) a fuel cell capable of converting hydrogen gas into electric power; and

(ii) an electrical storage system for storing electric power.

2. The machine of claim 1, wherein the machine comprises a grass mowing machine, and wherein the operating unit comprises a grass cutting unit.

3. The machine of claim 1, wherein the electrical storage system comprises an ultracapacitor pack.

4. A reel type cutting unit of a mower, which comprises:

(a) a cutting unit frame comprising a pair of laterally spaced side plates;

(b) a rotatable cutting reel cooperable with a fixed bedknife to sever grass, the cutting reel being rotatably journalled in the side plates for rotation between the side plates;

(c) an electric motor carried on an exterior of one of the side plates for powering the cutting reel, the electric motor comprising;

(i) a motor housing having a rotatable motor armature;

(ii) an output shaft driven from the motor armature with the output shaft being coupled to the cutting reel for rotating the cutting reel; and

(iii) wherein the output shaft is lower than the motor armature when the output shaft is coupled to the cutting reel.

5. The cutting unit of claim 4, wherein the output shaft is contained in a housing that is integral with the motor housing and extends downwardly from the motor housing.

6. The cutting unit of claim 5, wherein the output shaft is driven at a slower speed than the motor armature and the housing that contains the output shaft is a speed reduction housing.

7. The cutting unit of claim 4, further including an electronics housing that is integral with the motor housing, wherein the electronics housing contains the electronics for controlling and powering the motor.

8. The cutting unit of claim 7, wherein a substantial portion of the electronics housing stands off the motor housing to be separated from the motor housing by a gap or space.

9. The cutting unit of claim 4, further including a counterbalance to the weight of the electric motor which counterbalance is carried on an opposite side plate of the reel cutting unit.

10. The cutting unit of claim 9, wherein the counterbalance is a counterweight.

11. An electric motor for powering a rotatable cutting reel of a reel type cutting unit of a mower, which comprises:

(a) a motor housing having a rotatable motor armature, wherein the motor armature is operatively coupled to the cutting reel for rotating the cutting reel; and

(b) an electronics housing that is integral with the motor housing, wherein the electronics housing contains the electronics for controlling and powering the motor.

12. The electric motor of claim 11, wherein a substantial portion of the electronics housing stands off the motor housing to be separated from the motor housing by a gap or space.

13. A mower, which comprises:

(a) a frame;

(b) a plurality of ground engaging wheels attached to the frame for supporting the frame for movement over the ground;

(c) a traction system operatively connected to at least one of the ground engaging wheels for propelling the wheel to provide traction for the frame;

(d) at least one grass cutting unit carried on the frame for cutting grass;

(e) a lift and lower system for lifting the cutting unit out of engagement with the ground and for lowering the cutting unit into engagement with the ground; and

(f) an actuator for powering the lift and lower system during lifting of the cutting units out of engagement with the ground with the actuator being unpowered during lowering of the cutting units into engagement with the ground.

14. The mower of claim 13, wherein the lift and lower system comprises a hydraulic cylinder connected to the cutting unit, and wherein the actuator comprises a pump for pumping hydraulic fluid to the hydraulic cylinder to raise the cutting unit out of engagement with the ground, the pump being driven only when hydraulic fluid is being pumped to the hydraulic-cylinder.

15. The mower of claim 14, wherein the pump is electrically driven.

16. The mower of claim 14, wherein a reservoir of hydraulic fluid, the pump and a valve controlling flow through at least one outlet are packaged together as a single integrated actuator.