US-12616090-B2 - Suspension system for electric power equipment

US12616090B2US 12616090 B2US12616090 B2US 12616090B2US-12616090-B2

Abstract

A zero-turn radius lawnmower includes a chassis having a rear frame, a crossbeam, and a subframe, and a battery receptacle for receiving a battery pack. A first rear suspension cradle is rotatable coupled to the crossbeam on a first end, and is movably coupled to the first side panel on a second end. The first rear suspension cradle supports a first electric motor configured to rotate a first drive wheel supported by the first rear suspension cradle. A second rear suspension cradle is rotatably coupled to the crossbeam on a first end and movably coupled to the second side panel on a second end. The second suspension cradle supports a second electric motor configured to rotate a second drive wheel supported by the second rear suspension cradle. The first rear suspension cradle and the second rear suspension cradle are independently rotatable relative to the rear frame.

Inventors

Michael Broge
Victor Burgess
Derrick Camenga
Joshua R. Kowalski
Robert S. Laurin
Mark J. Melone

Assignees

BRIGGS & STRATTON, LLC

Dates

Publication Date: 20260505
Application Date: 20221014

Claims (16)

1 . A zero-turn radius lawnmower comprising: a rear frame including a first side panel, a second side panel, and a base panel, the first side panel and the second side panel being positioned on opposite sides of the base panel and together defining a battery receptacle for receiving a battery pack; a crossbeam coupled to and extending between the first side panel and the second side panel; a subframe coupled to the crossbeam, wherein the subframe supports a mower deck and at least two casters; a first rear suspension cradle directly and rotatably coupled to the crossbeam on a first end and movably coupled to the first side panel on a second end, the first rear suspension cradle supporting a first electric motor configured to rotate a first drive wheel supported by the first rear suspension cradle, wherein the first electric motor includes a drive shaft extending outward from a first end of a motor housing of the first electric motor and a stub shaft extending outward from a second end of the motor housing, opposite the first end; and a second rear suspension cradle directly and rotatably coupled to the crossbeam on a first end and movably coupled to the second side panel on a second end, the second rear suspension cradle supporting a second electric motor configured to rotate a second drive wheel supported by the second rear suspension cradle; wherein each of the first electric motor and the second electric motor is coupled to the battery pack, and wherein each of the first rear suspension cradle and the second rear suspension cradle is independently rotatable relative to the rear frame.
2 . The zero-turn radius lawnmower of claim 1 , wherein the second end of the first rear suspension cradle is movably coupled to the first side panel using a first shock absorbing assembly, and wherein the second end of the second rear suspension cradle is movably coupled to the second side panel using a second shock absorbing assembly.
3 . The zero-turn radius lawnmower of claim 2 , wherein both of the first shock absorbing assembly and the second shock absorbing assembly each comprise a damper and a spring, wherein the first shock absorbing assembly is configured to oppose rotation of the first rear suspension cradle relative to the rear frame and wherein the second shock absorbing assembly is configured to oppose rotation of the second rear suspension cradle relative to the rear frame.
4 . The zero-turn radius lawnmower of claim 3 , wherein the damper and the spring of the first shock absorbing assembly are arranged in series.
5 . The zero-turn radius lawnmower of claim 4 , wherein the damper is a dashpot-style damper.
6 . The zero-turn radius lawnmower of claim 2 , wherein the first shock absorbing assembly is a gas spring-style damper.
7 . The zero-turn radius lawnmower of claim 1 , wherein the first rear suspension cradle is formed by two parallel plates spaced apart from one another and rigidly coupled together.
8 . The zero-turn radius lawnmower of claim 7 , wherein the first rear suspension cradle is rotatably coupled to the crossbeam using an axle that extends through each of the two parallel plates.
9 . The zero-turn radius lawnmower of claim 1 , wherein the drive shaft is coupled to the first drive wheel through a belt-driven spindle assembly mounted on an outer surface of the first rear suspension cradle.
10 . A zero-turn radius lawnmower comprising: a rear frame defining a battery receptacle for receiving a battery pack; a crossbeam coupled to the rear frame; a subframe coupled to the crossbeam, wherein the subframe supports a mower deck and at least two casters, the mower deck including at least two deck motors to separately drive blades; a first rear suspension cradle including a first end rotatably coupled to the crossbeam at a pivot axis and a second end movably coupled to a first side of the rear frame, the first rear suspension cradle supporting a first electric motor configured to rotate a first drive wheel supported by the first rear suspension cradle, wherein the first rear suspension cradle includes a first plate and a second plate that are rigidly coupled together, and wherein the first rear suspension cradle includes an interior panel that extends along a bottom of the second plate to form a trough below a front end of the first electric motor; and a second rear suspension cradle including a first end rotatably coupled to the crossbeam at the pivot axis and a second end movably coupled to a second side of the rear frame, the second rear suspension cradle supporting a second electric motor configured to rotate a second drive wheel supported by the second rear suspension cradle; wherein each of the at least two deck motors, the first electric motor, and the second electric motor is coupled to the battery pack, and wherein each of the first rear suspension cradle and the second rear suspension cradle is independently rotatable relative to the rear frame.
11 . The zero-turn radius lawnmower of claim 10 , wherein the second end of the first rear suspension cradle is movably coupled to the rear frame using a first shock absorber, and wherein the second end of the second rear suspension cradle is movably coupled to the rear frame using a second shock absorber.
12 . The zero-turn radius lawnmower of claim 11 , wherein each of the first shock absorber and the second shock absorber each comprises a damper and a spring arranged in series.
13 . The zero-turn radius lawnmower of claim 10 , wherein each of the first electric motor, the second electric motor, and the at least two deck motors includes a separate and dedicated controller.
14 . A zero-turn radius lawnmower comprising: a rear frame defining a battery receptacle for receiving a battery pack; a crossbeam coupled to the rear frame; a subframe coupled to the crossbeam, wherein the subframe supports a mower deck and at least two casters; a first rear suspension cradle including a first end directly and rotatably coupled to the crossbeam at a pivot axis and movably coupled to a first side of the rear frame on a second end, the first rear suspension cradle supporting a first electric motor configured to rotate a first drive wheel supported by the first rear suspension cradle, wherein the first rear suspension cradle includes a first plate and a second plate that are rigidly coupled together, and wherein the first rear suspension cradle includes an interior panel that extends along a bottom of the second plate to form a trough below a front end of the first electric motor; and a second rear suspension cradle including a first end directly and rotatably coupled to the crossbeam at the pivot axis and movably coupled to a second side of the rear frame on a second end, the second rear suspension cradle supporting a second electric motor configured to rotate a second drive wheel supported by the second rear suspension cradle; wherein the first electric motor and the second electric motor are coupled to the battery pack and the battery pack is positioned laterally between the first electric motor and the second electric motor, and wherein each of the first rear suspension cradle and the second rear suspension cradle is independently rotatable relative to the rear frame.
15 . The zero-turn radius lawnmower of claim 14 , wherein the second end of the first rear suspension cradle is movably coupled to the rear frame using a first shock absorber, and wherein the second end of the second rear suspension cradle is movably coupled to the rear frame using a second shock absorber.
16 . The zero-turn radius lawnmower of claim 14 , further comprising a plurality of deck motors to separately drive blades, wherein each of the deck motors is coupled to the battery pack.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Application No. 63/256,281, filed on Oct. 15, 2021, the entire disclosure of which is hereby incorporated by reference herein. BACKGROUND Zero-turn radius (ZTR) lawnmowers are a commonly-used type of lawn and garden equipment. ZTR lawnmowers traditionally include two drive wheels and casters that are together able to move the lawnmower in a precise manner that allows for highly-controlled grass cutting operations. ZTR lawnmowers typically have a gasoline-powered engine and hydrostatic transmissions. SUMMARY One exemplary embodiment relates to a zero-turn radius lawnmower. The ZTR includes a chassis having a rear frame, a crossbeam, and a subframe. The rear frame includes a first side panel, a second side panel, and a base panel. The first side panel and second side panel are positioned on opposite sides of the base panel and together define a battery receptacle for receiving a removable and rechargeable battery pack. The crossbeam is coupled to and extends between the first side panel and the second side panel. The subframe is coupled to and suspended from the crossbeam, and supports a motor deck and at least two casters. A first rear suspension cradle is rotatable coupled to the crossbeam on a first end, and is movably coupled to the first side panel on a second end. The first rear suspension cradle supports a first electric motor configured to rotate a first drive wheel supported by the first rear suspension cradle. A second rear suspension cradle is rotatably coupled to the crossbeam on a first end and movably coupled to the second side panel on a second end. The second suspension cradle supports a second electric motor configured to rotate a second drive wheel supported by the second rear suspension cradle. Each of the first electric motor and the second electric motor is coupled to the removable and rechargeable battery pack. Each of the first rear suspension cradle and the second rear suspension cradle is independently rotatable relative to the rear frame. Another embodiment relates to a zero-turn radius lawnmower that includes a rear frame defining a battery receptacle for receiving a removable and rechargeable battery pack, and a crossbeam coupled to the rear frame, a subframe coupled to the crossbeam. The subframe supports a mower deck and at least two casters, and the mower deck includes at least two deck motors to separately drive blades. A first rear suspension cradle is rotatably coupled to the crossbeam on a first end and movably coupled to a first side of the rear frame on a second end. The first rear suspension cradle supports a first electric motor configured to rotate a first drive wheel supported by the first rear suspension cradle. A second rear suspension cradle is rotatably coupled to the crossbeam on a first end and movably coupled to a second side of the rear frame on a second end. The second rear suspension cradle supports a second electric motor configured to rotate a second drive wheel supported by the second rear suspension cradle. Each of the at least two deck motors, the first electric motor, and the second electric motor is coupled to the removable and rechargeable battery pack. Each of the first rear suspension cradle and the second rear suspension cradle is independently rotatable relative to the rear frame. Another embodiment relates to a zero-turn radius lawnmower that includes a rear frame defining a battery receptacle for receiving a removable and rechargeable battery pack, a crossbeam coupled to the rear frame, and a subframe coupled to the crossbeam. The subframe supports a mower deck and at least two casters. A first rear suspension cradle is rotatably coupled to the crossbeam on a first end and movably coupled to a first side of the rear frame on a second end. The first rear suspension cradle supports a first electric motor configured to rotate a first drive wheel supported by the first rear suspension cradle. A second rear suspension cradle is rotatably coupled to the crossbeam on a first end and movably coupled to a second side of the rear frame on a second end. The second rear suspension cradle supports a second electric motor configured to rotate a second drive wheel supported by the second rear suspension cradle. The first electric motor and the second electric motor are coupled to the battery pack and the battery pack is positioned laterally between the first electric motor and the second electric motor. Each of the first rear suspension cradle and the second rear suspension cradle is independently rotatable relative to the rear frame. This summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein, taken in conjunction with the accompanying figures, wherein like refere