Axial Pump Assemblies

Patent metadata

Field	Value
Publication number	US-2022349393-A1
Application number	US-202217867207-A
Country	US
Kind code	A1
Filing date	Jul 18, 2022
Priority date	Jul 17, 2019
Publication date	Nov 3, 2022
Grant date	—

Abstract

Embodiments of the invention provide a pump assembly for a hydraulic tool. The pump assembly can include a reciprocating element that is configured to move between a retracted position and an extended position, a cam surface in the reciprocating element that can engage cam followers, a rotating element that can receive rotational input, and a base that can at least partially surrounds the rotating element. Movement of the cam followers along the cam surface can move the reciprocating element from the retracted position to the extended position.

First claim

1 . An axial pump assembly for a hydraulic tool, the axial pump assembly comprising:
a reciprocating block having ramped radial channels extending radially outward from an inner circumferential surface of the reciprocating block; a sun driver configured to be operatively coupled to a motor shaft; ball elements configured to roll on a race portion, each ball element arranged at least partially within a respective ramped radial channel of the ramped radial channels; and a base at least partially enclosing the sun driver and the ball elements; movement of the ball elements radially outward through the ramped radial channels driving the reciprocating block away from the base, and movement of the ball elements radially inward through the ramped radial channels driving the reciprocating block toward the base.

2 . The axial pump assembly of claim 1 , further comprising:
planetary elements having geared portions that mesh with geared portions of the sun driver.

3 . The axial pump assembly of claim 2 , wherein the ball elements are configured to roll on the race portion of each planetary element.

4 . The axial pump assembly of claim 3 , wherein the base includes a geared portion configured to mesh with the planetary elements and provide speed reduction to the axial pump assembly.

5 . The axial pump assembly of claim 1 , wherein the reciprocating block is configured to be operatively coupled to a pump piston of the hydraulic tool.

6 . The axial pump assembly of claim 5 , wherein the axial pump assembly is configured to be arranged within the hydraulic tool such that the motor shaft is substantially coaxial with a line of action of the reciprocating block.

7 . The axial pump assembly of claim 1 , wherein the race portion is a sinusoidal-shaped cam groove formed on the sun driver.

8 . The axial pump assembly of claim 1 , wherein the ramped radial channels include a first pair of opposing ramped radial channels that are ramped towards the base.

9 . An axial pump assembly for a hydraulic tool, the axial pump comprising:
a pump piston, a pair of cam follower bearings coupled to opposite ends of the pump piston; an eccentric bearing configured to drive cycloidal transmission of the pump piston; a base; and a cycloidal disk configured to be operatively coupled to a motor shaft of the hydraulic tool by way of the eccentric bearing, the cycloidal disk including a second-stage cam portion configured to transmit rotational motion to axial displacement of the pump piston; rotation of the cycloidal disk and the second-stage cam portion pushing the pair of cam follower bearings and causing reciprocating motion of the pump piston between an extended position and a retracted position.

10 . The axial pump of claim 9 , wherein the pump piston is arranged transverse to an axis about which the cycloidal disk and base are arranged, with a longitudinal axis of the pump piston substantially intersecting with the axis.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Myrhum Jr James O

Classifications

• F04B9/042 Primary

  the means being cams · CPC title

• F16H25/12

  with reciprocation along the axis of rotation, e.g. gearings with helical grooves and automatic reversal · CPC title

• F04B1/043 Primary

  Hydraulic arrangements · CPC title

• F04B1/0413

  Cams · CPC title