Actuating Piston and Adjustment Installation

Patent metadata

Field	Value
Publication number	US-2021102559-A1
Application number	US-202017026431-A
Country	US
Kind code	A1
Filing date	Sep 21, 2020
Priority date	Oct 2, 2019
Publication date	Apr 8, 2021
Grant date	—

Abstract

An actuating piston for a hydrostatic adjustment installation includes at least one sealing and guiding unit which is insertable into a circumferential recess of an actuating piston. The circumferential recess is composed of two regions, and has the effect of improving the guiding and sealing of the actuating piston. The actuating piston is arranged in an adjustment installation.

First claim

1 . An actuating piston for a hydrostatic adjustment installation comprising:
an external shell face defining a circumferential recess; and a sealing and guiding unit encompassing the external shell face in a region of the circumferential recess, the sealing and guiding unit configured to guide the actuating piston in an actuating cylinder of the hydrostatic adjustment installation so as to be stable in terms of tilting and displaceable in an axial manner, and to seal a gap between the external shell face of the actuating piston and an internal shell face of the actuating cylinder, wherein the circumferential recess has a first region having a guide region for the sealing and guiding unit that is configured to absorb transverse forces, and a second region having protrusions, and wherein the first region has a larger axial extent than the second region.

2 . The actuating piston according to claim 1 , wherein an axial extent of the guide region is larger by a multiple than an axial extent of the protrusions.

3 . The actuating piston according to claim 1 , wherein the sealing and guiding unit is configured so as to be integral.

4 . The actuating piston according to claim 1 , wherein the protrusions in the second region, when viewed in a direction of an axial force resulting from an actuating pressure, have a decreasing diameter.

5 . The actuating piston according to claim 1 , wherein the protrusions push at least partially into a circumference of the sealing and guiding unit so as to engage behind the sealing and guiding unit, and/or the protrusions plunge into recesses of the sealing and guiding unit.

6 . The actuating piston according to claim 1 , wherein the protrusions have end face portions that absorb axial forces acting on the sealing and guiding unit, the protrusions configured to seal a gap between the external shell face of the actuating piston and the internal shell face of the actuating cylinder.

7 . The actuating piston according to claim 5 , wherein the protrusions push into the sealing and guiding unit during the deformation under a transverse force and/or according to wear takes place by at least 40% of an initial thickness of the sealing and guiding unit in a region of a largest protrusion of the protrusions.

8 . The actuating piston according to claim 1 , wherein the sealing and guiding unit, upon being applied to the actuating piston, has a sealing diameter which is at most 0.5% larger than an internal diameter of the actuating cylinder.

9 . The actuating piston according to claim 1 , wherein a diameter in end portions of the circumferential recess is smaller than a diameter of a contact area of the guide region.

10 . The actuating piston according to claim 9 , wherein the sealing and guiding unit, by way of the end portions of the circumferential recess produces a gap, which is reduced because of internal stresses of the sealing and guiding unit, the sealing and guiding unit plunging at least partially into the gap such that a chamfer is provided on the sealing and guiding unit.

11 . An adjustment installation comprising:
an actuating cylinder; and an actuating piston comprising:
an external shell face defining a circumferential recess; and
a sealing and guiding unit encompassing the external shell face in a region of the circumferential recess, the sealing and guiding unit configured to guide the actuating piston in the actuating cylinder so as to be stable in terms of tilting and displaceable in an axial manner, and to seal a gap between the external shell face of the actuating piston and an internal shell face of the actuating cylinder,
wherein the circumferential recess has a first region having a guide region for the sealing and guiding unit that is configured to absorb transverse forces, and a second region having protrusions, and wherein the first region has a larger axial extent than the second region.

12 . The actuating piston according to claim 1 , wherein the actuating piston is configured for adjusting a displacement volume of a hydrostatic positive-displacement machine having a variable displaced volume.

13 . The actuating piston according to claim 7 , wherein the protrusions push into the sealing and guiding unit during the deformation under the transverse force and/or according to wear by at most 55% of the initial thickness of the sealing and guiding unit in the region of the largest protrusion.

14 . The actuating piston according to claim 13 , wherein the protrusions push into the sealing and guiding unit during the deformation under the transverse force and/or according to wear by at least 42% and at most 50% of the initial thickness of the sealing and guiding unit in the region of the largest protrusion.

Assignees

• Bosch Gmbh Robert

Inventors

• Huehn Bernd

Classifications

• F03C1/0686

  by changing the inclination of the swash plate · CPC title

• F04B1/295

  by changing the inclination of the swash plate · CPC title

• F04B1/324 Primary

  by changing the inclination of the swash plate · CPC title

• F04B49/002

  Hydraulic systems to change the pump delivery · CPC title

• F04B1/146

  Swash plates; Actuating elements · CPC title