Piston type pump drive arrangement

Patent metadata

Field	Value
Publication number	US-12416296-B2
Application number	US-201917612600-A
Country	US
Kind code	B2
Filing date	May 21, 2019
Priority date	May 21, 2019
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A piston type pump includes a pump housing having a pump inlet, a pump outlet, and a piston arrangement connected to a drive shaft. The drive shaft is configured to drive the piston arrangement, and the drive shaft includes a first eccentric. The piston arrangement has a first primary stage piston connected to a first sliding block guide slidably seated on the first eccentric. The first sliding block guide has a main axis, a minor axis, and an inner surface. A first sliding bush is arranged between the first eccentric and the first sliding block guide. The outer surface of the first sliding bush corresponds to the inner surface of the first sliding block guide. Translational movement of the first sliding bush relative to the first sliding block guide is allowed along the main axis and restricted along the minor axis.

First claim

The invention claimed is:

1. A piston type pump, comprising:
a pump housing having a pump inlet, a pump outlet, and a piston arrangement connected to a drive shaft, the drive shaft being configured to drive the piston arrangement, the drive shaft comprising a first eccentric,
the piston arrangement having a first primary stage piston connected to a first sliding block guide slidably seated on the first eccentric, the first sliding block guide having a main axis, a minor axis, and an inner surface,
wherein a first sliding bush is arranged between the first eccentric and the first sliding block guide, wherein an outer surface of the first sliding bush corresponds to the inner surface of the first sliding block guide and a translational movement of the first sliding bush relative to the first sliding block guide is allowed along the main axis and restricted along the minor axis,
wherein the outer surface of the first sliding bush is tapered along a first direction that is parallel to a rotational axis of the drive shaft towards a first end of the drive shaft, and
wherein the inner surface of the first sliding block guide is correspondingly tapered along the first direction towards the first end of the drive shaft.

2. The piston type pump according to claim 1 , wherein the first sliding bush is biased towards the first end of the drive shaft by a first biasing member such that the outer surface of the first sliding bush contacts the inner surface of the first sliding block guide.

3. The piston type pump according to claim 2 , wherein the first biasing member applies a first biasing force in a range of larger 0 N to 40 N on the first sliding bush in the first direction that is parallel to the rotational axis of the drive shaft.

4. The piston type pump according to claim 2 , wherein the first biasing member is a spring clip attached to the first sliding block guide.

5. The piston type pump according to claim 2 , wherein the first biasing member is one of a wave spring, a flat coil, a Belleville washer and/or a wave washer that is connected to the first eccentric by a first retaining screw.

6. The piston type pump according to claim 2 , wherein the first sliding bush comprises an end stop that is larger than a maximum slot width of the inner surface of the first sliding block guide.

7. The piston type pump according to claim 6 , wherein the end stop is spaced from a corresponding stop face of the first sliding block guide.

8. The piston type pump according to claim 1 , wherein the drive shaft further comprises a second eccentric, wherein the piston arrangement further comprises a second sliding block guide slidably seated on the second eccentric, and wherein a second sliding bush is arranged between the second eccentric and the second sliding block guide.

9. The piston type pump according to claim 8 , wherein an outer surface of the second sliding bush facing the second sliding block guide is tapered along a second direction towards a second end of the drive shaft, and
wherein an inner surface of the second sliding block guide corresponding to the outer surface of the second sliding bush is tapered along the second direction towards a second end of the drive shaft.

10. The piston type pump according to claim 8 , wherein a tapered end of the first sliding bush faces a tapered end of the second sliding bush.

11. The piston type pump according to claim 1 , wherein the first sliding bush is rotationally fixed to the first sliding block guide.

12. The piston type pump according to claim 1 , wherein the piston arrangement further comprises a first primary stage cylinder formed in the pump housing, wherein the first primary stage piston is slidably seated in the first primary stage cylinder, and
a first secondary stage piston being slidably seated in a first secondary stage cylinder formed in the first primary stage piston.

13. A vehicle comprising the piston type pump according to claim 1 .

Assignees

• Zf Cv Systems Europe Bv

Inventors

• Todman Peter

Classifications

• F04B53/147

  Mounting or detaching of piston rod · CPC title

• F04B39/0005

  adaptations of pistons · CPC title

• F04B9/047

  the means being pin-and-slot mechanisms · CPC title

• F04B1/053

  with actuating or actuated elements at the inner ends of the cylinders · CPC title

• F04B1/0426

  Arrangements for pressing the pistons against the actuated cam; Arrangements for connecting the pistons to the actuated cam · CPC title