Articulated riding lawn mower including distributed battery system

Patent metadata

Field	Value
Publication number	US-9699965-B2
Application number	US-201114232318-A
Country	US
Kind code	B2
Filing date	Jul 14, 2011
Priority date	Jul 14, 2011
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A riding lawn mower may include a first frame portion, a second frame portion, an articulated joint and a battery system. The articulated joint may couple the first frame portion to the second frame portion. The battery system may include a first battery and a second battery. The first and second batteries may be electrically connected in series and collectively coupled to a load. The first battery may be mounted to the first frame portion and the second battery may be mounted to the second frame portion.

First claim

That which is claimed:

1. A riding lawn mower comprising:
a front frame portion;
a rear frame portion;
an articulated joint operably coupling the front frame portion to the rear frame portion, wherein the rear frame portion is pivotable relative to the front frame portion about a vertical axis defined by the articulated joint;
a front wheel axle disposed on the front frame portion;
a rear wheel axle disposed on the rear frame portion;
an electric drive motor disposed on the rear frame portion and operably coupled to a first rear wheel and second rear wheel disposed on the rear wheel axle in order to drive the first rear wheel and second rear wheel; and
a battery system comprising a first battery and a second battery, the first and second batteries being electrically connected in series and collectively electrically coupled to a load comprising at least the electric drive motor,
wherein the first battery is disposed on the front frame portion between the front wheel axle and the articulated joint;
wherein the second battery is disposed on the rear frame portion completely rearward of the rear wheel axle and the electric drive motor; and
wherein a longitudinal axis of the second battery is perpendicular to a longitudinal axis of the riding lawn mower,
wherein the electric drive motor is disposed within a drive motor compartment, the drive motor compartment being disposed on the rear frame portion higher than a first horizontal plane defined by the rear wheel axle.

2. The riding lawn mower of claim 1 , further comprising:
a front wheel operably coupled to the front frame portion; and
wherein the riding lawn mower is configured to steer by pivoting the rear frame portion relative to the front frame portion about the articulated joint such that the first rear wheel and the second rear wheel change orientation relative to the front wheel.

3. The riding lawn mower of claim 1 , further comprising:
a seat for an operator, wherein the first battery and the second battery are disposed lower than a second horizontal plane defined by the bottom of the seat.

4. The riding lawn mower of claim 1 , wherein the first battery and the second battery are disposed proximate to or higher than the first horizontal plane.

5. The riding lawn mower of claim 1 , further comprising:
a front-mount cutting deck disposed forward of the front wheel axle, and
wherein the load further comprises:
a cutting motor configured to drive a cutting blade, wherein the cutting motor and the electric drive motor are electrically coupled in parallel to the battery system.

6. The riding lawn mower of claim 1 , wherein the riding lawn mower is an electric riding lawn mower and does not comprise a gas engine.

7. The riding lawn mower of claim 1 , wherein the battery system further compromises:
a third battery electrically connected in series to the first battery and the second battery,
wherein the third battery is operably coupled to the front frame portion, and
wherein the first battery, second battery, and third battery are each rechargeable twelve-volt lead-acid batteries.

8. The riding lawn mower of claim 1 , wherein a position of the first battery between the front wheel axle and the articulated joint and the second battery completely rearward of the rear wheel axle and the electric drive motor, balances the weight of the battery system across the front axle and the rear axle.

9. The riding lawn mower of claim 1 , wherein a position of the first battery between the front wheel axle and the articulated joint and the second battery completely rearward of the rear wheel axle and the electric drive motor, balances the weight of the battery system across the front axle, the rear axle, and a frame comprising the front frame portion, the rear frame portion and the articulated joint.

10. The riding lawn mower of claim 1 ,
wherein the first rear wheel and the second rear wheel are operably coupled to each end of the rear wheel axle; and
a mechanical differential operably coupling the rear wheel axle to the electric drive motor so that when the drive motor is powered by the battery system, rotational forces are distributed to the rear wheel axle, thereby rotating the first rear wheel and the second rear wheel.

11. The riding lawn mower of claim 10 , wherein, in response to the electric drive motor being electrically powered, the mechanical differential outputs different rotational forces to each of the first rear wheel and the second rear wheel so the first rear wheel is forced to rotate at a different speed than the second rear wheel.

12. The riding lawn mower of claim 10 ,
wherein the rear wheel axle comprises a first section and a second section and the mechanical differential comprises a first portion and a second portion,
wherein the first portion of the mechanical differential is operably coupled to the first section of the rear wheel axle,
wherein the second portion of the mechanical differential is operably coupled to the second section of the rear wheel axle,
wherein the mechanical differential receives rotational forces from the electric drive motor and translates the rotational forces to differing rotational forces to the first section of the rear wheel axle and the second section of the rear wheel axle so that the first and second sections of the rear wheel axle rotate at different speeds.

13. The riding lawn mower of claim 10 , further comprising a chain connecting the electric drive motor and the mechanical differential, wherein the chain is connected to a gear of the electric drive motor and a gear connected to the mechanical differential.

14. A riding lawn mower comprising:
a front frame portion;
a front compartment disposed on the front frame portion;
a rear frame portion;
a drive motor compartment disposed on the rear frame portion;
an articulated joint operably coupling the front frame portion to the rear frame portion, wherein the rear frame portion is pivotable relative to the front frame portion about a vertical axis defined by the articulated joint;
a front wheel axle disposed on the front frame portion;
a rear wheel axle disposed on the rear frame portion;
an electric drive motor disposed on the rear frame portion and operably coupled to a first rear wheel and a second rear wheel disposed on the rear wheel axle in order to drive the first rear wheel and the second rear wheel; and
a battery system comprising a first battery and a second battery, the first and second batteries being electrically connected in series and collectively electrically coupled to a load comprising at least the electric drive motor,
wherein the first battery is disposed on the front frame portion between the front wheel axle and the articulated joint in an interior area of the front compartment; and
wherein the second battery is disposed on the rear frame portion completely rearward of the rear wheel axle and the electric drive motor, the second battery and electric drive motor are being disposed in an interior area of the drive motor compartment,
wherein the electric drive motor is disposed within the drive motor compartment, the drive motor compartment being disposed on the rear frame portion higher than a horizontal plane defined by the rear wheel axle.

15. The riding lawn mower of claim 14 , wherein the load further comprises:
a cutting motor configured to drive a cutting blade, the cutting motor disposed forward of the front wheel axle.

16. The riding lawn mower of claim 14 , further comprising:
a recharging receptacle operably coupled to the rear frame portion rearward of the second battery,

Assignees

• Schygge Sebastian
• Östberg Fredrik
• Viskari Pasi
• Husqvarna Ab

Inventors

• Schygge Sebastian
• Östberg Fredrik
• Viskari Pasi

Classifications

• B60K1/04

  of the electric storage means for propulsion · CPC title

• B60L2200/40

  Working vehicles · CPC title

• A01D69/02

  electric · CPC title

• B60K2001/0411

  Arrangement in the front part of the vehicle · CPC title

• A01D34/78 Primary

  electric · CPC title