Integrated electro-hydraulic unit housing

Patent metadata

Field	Value
Publication number	US-12435711-B2
Application number	US-202318465819-A
Country	US
Kind code	B2
Filing date	Sep 12, 2023
Priority date	Sep 12, 2023
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

An integrated electro-hydraulic unit has a hydraulic machine, an electric machine encircling the hydraulic machine and a housing at least partially surrounding the electric machine and the hydraulic machine. The hydraulic machine includes a rotary working group configured to pump a fluid. The electric machine includes a stator and a rotor coupled to the rotary working group such that the rotor drives the rotary working group. The housing includes a front cap and an end cap each having a plurality of tie rod openings. The housing includes a plurality of tie rods and a housing shell encircling the electric machine and positioned between the front and end caps. The tie rods extend through the openings in the front cap and end cap. Nuts are tightened on the tie rods such that the front cap, the end cap, and the housing shell are compressed via tension in the tie rods.

First claim

What is claimed is:

1. An integrated electro-hydraulic unit comprising:
a hydraulic machine including a rotary working group configured to pump a working fluid;
an electric machine encircling the hydraulic machine, the electric machine including a stator and a rotor coupled to the rotary working group such that the rotor drives the rotary working group about an axis; and
a housing at least partially surrounding the electric machine and the hydraulic machine, the housing including
a front cap having a front plate with a plurality of first tie rod openings,
an end cap having an end plate with a plurality of second tie rod openings,
a housing shell encircling the electric machine and positioned between the front cap and the end cap,
a plurality of tie rods, each tie rod having a first threaded end extending through a respective one of the plurality of first tie rod openings and a second end extending through a respective one of the plurality of second tie rod openings, and
a plurality of nuts threaded onto each of the first threaded ends of the plurality of tie rods and tightened onto the front cap such that the front cap, the end cap, and the housing shell are compressed via tension in the plurality of tie rods.

2. The integrated electro-hydraulic unit of claim 1 , wherein the housing shell includes a first axial end that abuts the front cap and a second axial end opposite the first axial end, and wherein the second axial end abuts the end cap.

3. The integrated electro-hydraulic unit of claim 1 , wherein the housing shell is a hollow cylinder.

4. The integrated electro-hydraulic unit of claim 1 , wherein the hydraulic machine includes a shaft rotatable about the axis and a bearing at least partially supporting the shaft, wherein the bearing is supported on the front cap of the housing, and wherein the compression of the front cap, the end cap, and the housing shell exerts an axial preload on the bearing.

5. The integrated electro-hydraulic unit of claim 1 , wherein the hydraulic machine and the electric machine define a shared rotational axis, and wherein the tie rods are radially outward from the housing shell in relation to the shared rotational axis.

6. The integrated electro-hydraulic unit of claim 5 , wherein the tie rods are evenly spaced around an entirety of the shared rotational axis.

7. An integrated electro-hydraulic unit comprising:
a hydraulic machine including a rotary working group configured to pump a working fluid;
an electric machine encircling the hydraulic machine, the electric machine including a stator and a rotor coupled to the rotary working group such that the rotor drives the rotary working group about an axis; and
a housing at least partially surrounding the electric machine and the hydraulic machine, the housing including
a front cap having a front plate defining a first outer axial surface and a first inner axial surface opposite the first outer axial surface,
an end cap having an end plate defining a second outer axial surface and a second inner axial surface opposite the second outer axial surface, the second inner axial surface facing the first inner axial surface of the front cap,
a housing shell extending between the front cap and the end cap, the housing shell having a first axial end abutting the first inner axial surface and a second axial end abutting the second inner axial surface, and
a plurality of tie rods extending from a plurality of first tie rod openings in the front cap to a plurality of second tie rod openings in the end cap,

wherein the plurality of tie rods are tensioned between the front cap and the end cap such that the end cap, the front cap, and the housing shell are compressed.

8. The integrated electro-hydraulic unit of claim 7 , wherein the housing shell defines an inner circumferential surface extending from the first axial end to the second axial end, and wherein the front cap has a first annular ridge extending from the first inner axial surface, and wherein the inner circumferential surface of the housing shell centers the first annular ridge on the axis.

9. The integrated electro-hydraulic unit of claim 8 , wherein the first annular ridge has a first annular groove, wherein a first seal is positioned in the first annular groove, and wherein the first seal contacts the first annular ridge and the inner circumferential surface such that the housing shell and the front cap are fluidly sealed.

10. The integrated electro-hydraulic unit of claim 9 , wherein the end cap has a second annular ridge extending from the second inner axial surface, and wherein the inner circumferential surface of the housing shell centers the second annular ridge on the axis.

11. The integrated electro-hydraulic unit of claim 10 , wherein the second annular ridge has a second annular groove, wherein a second seal is positioned in the second annular groove, wherein the second seal contacts the second annular ridge and the inner circumferential surface such that the housing shell and the end cap are fluidly sealed.

12. The integrated electro-hydraulic unit of claim 7 , wherein the electric machine includes a bearing which supports a shaft and which is positioned on the front cap, and wherein the compression of the front cap, the end cap, and the housing shell exerts an axial preload on the bearing.

13. An integrated electro-hydraulic unit comprising:
an electric machine including a stator and a rotor,
a hydraulic machine including
a shaft,
a bearing supporting the shaft,
a cylinder block driven about an axis by the rotor and coupled to the shaft,
a plurality of pistons received in the cylinder block,
a swashplate configured to axially move the plurality of pistons, and
a valve plate including a plurality of ports, the plurality of ports including a first port and a second port, each of the first and second ports are configured to exchange a working fluid with the cylinder block by action of the plurality of pistons; and

a housing having
a front cap having a front plate and a projection extending from the front plate, the projection defining a projection distal end which abuts the swashplate,
an end cap having an end plate and a protrusion extending from the end plate, the protrusion defining a protrusion distal end in which a bearing recess is formed, and
a housing shell encircling the electric machine and sandwiched between the front cap and the end cap,

wherein the bearing is positioned in the bearing recess of the protrusion such that the protrusion supports the bearing and the shaft, and
wherein a plurality of tie rods are tensioned on the front cap and the end cap such that the end cap, the front cap, and the housing shell are compressed.

14. The integrated electro-hydraulic unit of claim 13 , wherein the bearing is a first bearing and the hydraulic machine includes a second bearing supporting the shaft, and wherein the projection of the front cap includes a central opening which receives the second bearing.

15. The integrated electro-hydraulic unit of claim 13 , wherein the projection of the front cap includes a pin recess in the projection distal end, and wherein a pin is positioned in the pin recess and in the swashplate such that the swashplate is rotationally fixed.

16. The integrated electro-hydraulic unit of claim 13 , wherein the protrusion of the end cap has a pin recess in the protrusion distal end, and wherein a pin is positioned in the pin recess and in the valve plate such that the valve plate is rotationally fixed.

17. The integrated electro-hydraulic unit of claim 13 , wherein the compression

Assignees

• Bosch Gmbh Robert

Inventors

• Busquets Enrique
• Guender Andreas

Classifications

• F04B1/2071

  Bearings for cylinder barrels · CPC title

• F04B1/2064

  Housings · CPC title

• F04B1/2085

  Bearings for swash plates or driving axles · CPC title

• F04B1/2028

  Bearings · CPC title

• F04B53/22

  Arrangements for enabling ready assembly or disassembly · CPC title