Integrated drive and hydraulic actuator unit

Patent metadata

Field	Value
Publication number	US-11401145-B2
Application number	US-201916549813-A
Country	US
Kind code	B2
Filing date	Aug 23, 2019
Priority date	Aug 23, 2019
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

A housing for a hydraulic actuator unit of a pallet truck is disclosed. The housing includes a lift motor mount for mounting a lift motor to the housing and a pump mount for mounting a hydraulic pump to the housing, and couples the pump to the lift motor when each are mounted. The housing includes a hydraulic cylinder with a cylinder rod, which is positioned based on the fluid level in the hydraulic cylinder; a reservoir to store fluid for actuation of the cylinder rod; and one or more fluid galleries that extend, internal to the housing, among the fluid reservoir, the pump mount, and the hydraulic cylinder. A traction motor mount mounts the traction motor, which is coupled to a steering unit of the pallet truck and controls actuation of a traction wheel of the pallet truck when the traction motor is mounted to the traction motor mount.

First claim

What is claimed is:

1. A housing for a hydraulic actuator unit of a pallet truck, comprising:
a lift motor mount for mounting a lift motor and pump of the hydraulic actuator unit to the housing;
a pump mount for mounting a hydraulic pump of the hydraulic actuator unit to the housing, wherein the hydraulic pump is coupled to the lift motor when the lift motor is mounted to the lift motor mount and the hydraulic pump is mounted to the pump mount;
a hydraulic cylinder to receive a cylinder rod, wherein the cylinder rod is positioned based on an amount of fluid within the hydraulic cylinder;
a fluid reservoir to store fluid for actuation of the cylinder rod, wherein the housing has one or more fluid galleries that extend, internal to the housing, among the fluid reservoir, the pump mount, and the hydraulic cylinder; and
a traction motor mount for mounting a traction motor, wherein the traction motor is coupled to a steering unit of the pallet truck and controls actuation of a traction wheel of the pallet truck when the traction motor is mounted to the traction motor mount;
wherein the lift motor mount, the pump mount, the hydraulic cylinder, the fluid reservoir, and the traction motor mount are elements of a unitary physical structure.

2. The housing of claim 1 , further comprising a support frame mount, the support frame mount to mount the housing to a support frame of the pallet truck to form a frame of the pallet truck.

3. The housing of claim 1 , wherein the traction motor mount includes steer bearing mounts for mounting steer bearings to the housing, wherein the steer bearings allow at least a portion of the steering unit to be rotated relative to the housing while the traction motor mount maintains a position of the traction motor relative to the housing.

4. The housing of claim 1 , wherein the housing is a casting with at least a portion of the one or more fluid galleries formed during a casting process of the housing.

5. The housing of claim 1 , wherein the housing further comprises a lift linkage mount for connecting a lift linkage to the housing.

6. The housing of claim 1 , further comprising valve mounts for a non-return valve, a lower valve, and a pressure relief valve located along the one or more fluid galleries.

7. A hydraulic actuator unit for a pallet truck, comprising:
a housing to couple the hydraulic actuator unit to a support frame of the pallet truck, wherein the housing is a unitary physical structure that includes a fluid reservoir, a lift motor mount, a pump mount, a traction motor mount, and a hydraulic cylinder;
a cylinder rod that extends into the hydraulic cylinder, wherein a position of the cylinder rod depends on an amount of fluid located within the hydraulic cylinder;
a lift motor mounted to the lift motor mount of the housing;
a hydraulic pump mounted to the pump mount of the housing and coupled to the lift motor, wherein the lift motor controls actuation of the hydraulic pump, and wherein the housing has one or more fluid galleries that extend, internal to the housing, among the fluid reservoir, the hydraulic pump, and the hydraulic cylinder, the hydraulic pump to transmit fluid from the fluid reservoir to the hydraulic cylinder via at least a portion of the one or more fluid galleries when the hydraulic pump is actuated; and
a traction motor mounted to the traction motor mount of the housing over a drive aperture of the housing, wherein a portion of a steering unit of the pallet truck extends within the drive aperture when the hydraulic unit is coupled to the pallet truck and engages with the traction motor, the traction motor to control actuation of a traction wheel of the steering unit.

8. The hydraulic actuator unit of claim 7 , wherein the housing is further to couple to a lift linkage of the pallet truck, wherein the housing, the support frame, and the lift linkage of the pallet truck forms a frame of the pallet truck.

9. The hydraulic actuator unit of claim 8 , wherein the housing has a lift linkage aperture that is to receive a portion of the lift linkage to couple the housing to the lift linkage.

10. The hydraulic actuator unit of claim 7 , further comprising steer bearings mounted to sidewalls encircling the drive aperture, the steer bearings to engage with the portion of the steering unit and allow the steering unit to rotate relative to the housing while a position of the traction motor is maintained relative to the housing.

11. The hydraulic actuator unit of claim 7 , wherein the cylinder rod is to couple to a fork frame of the pallet truck and the cylinder rod is to lift and lower the fork frame based on the position of the cylinder rod.

12. The hydraulic actuator unit of claim 7 , further comprising one or more valves to control flow of fluid through the one or more fluid galleries.

13. The hydraulic actuator unit of claim 12 , wherein the one or more valves includes a non-return valve coupled to a first fluid gallery of the one or more fluid galleries, a lower valve coupled to a second fluid gallery of the one or more fluid galleries, and a pressure relief valve coupled to a third fluid gallery of the one or more fluid galleries, wherein the first fluid gallery extends between the hydraulic pump and the hydraulic cylinder, the second fluid gallery extends between the hydraulic cylinder and the fluid reservoir, and the third fluid gallery extends between the hydraulic cylinder and the fluid reservoir.

14. The hydraulic actuator unit of claim 7 , wherein the cylinder rod is located between the steering unit and a fork frame of the pallet truck, and wherein the lift motor and the hydraulic pump are located to a side of the cylinder rod between the steering unit and the fork frame.

15. A pallet truck, comprising:
a steering unit that includes a traction wheel of the pallet truck;
a fork frame that includes a pair of forks configured to engage with a pallet; and
a frame coupled to the steering unit, wherein the frame includes:
a hydraulic actuator unit that includes:
a housing that is a unitary physical structure that includes a fluid reservoir, a lift motor mount, a pump mount, a traction motor mount, and a hydraulic cylinder;
a cylinder rod that extends into the hydraulic cylinder and is coupled to the fork frame, wherein a position of the cylinder rod depends on an amount of fluid located within the hydraulic cylinder, and wherein the position of the cylinder rod controls a vertical position of the fork frame;
a lift motor mounted to the lift motor mount of the housing;
a hydraulic pump mounted to the pump mount of the housing and coupled to the lift motor, wherein the housing has one or more fluid galleries that extend, internal to the housing, among the fluid reservoir, the hydraulic pump, and the hydraulic cylinder; and
a traction motor mounted to the traction motor mount of the housing,

wherein the traction motor is coupled to the steering unit and controls actuation of the traction wheel; and
lift linkage coupled to the hydraulic actuator unit, where the lift linkage extends beneath the fork frame.

16. The pallet truck of claim 15 , wherein the frame further includes a support frame coupled to the housing, wherein the support frame extends away from the fork frame and provides stability for the pallet truck.

17. The pallet truck of claim 15 , wherein the hydraulic actuator unit further includes steer bearings to engage with the steering unit, and wherein the steer bearings allow the steering unit to rotate while the traction motor remains static.

18. The pallet truck of claim 17 , wherein

Assignees

• Hyster Yale Group Inc

Inventors

• White Andrew

Classifications

• B66F9/00

  Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes (mobile or transportable lifts in, or associated with, buildings and specially adapted to be shifted from one part of a building or other structure to another part or to another building or structure B66B9/16; cranes B66C) · CPC title

• B66F9/22 Primary

  Hydraulic devices or systems · CPC title

• B62B3/0618 Primary

  using fluid lifting mechanisms · CPC title

• B66F9/07572

  Propulsion arrangements · CPC title