IP Library Granted Patent US 7,971,697
Granted Patent B2
US 7,971,697 · App. 10/592,504 · Granted Jul 5, 2011

Coupling device

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Quick Facts
Patent No.
US 7,971,697
App. No.
10/592,504
Granted
Jul 5, 2011
Kind
B2
Abstract

A clutch device for a motor vehicle has friction elements around which coolant flows and which, by way of a piston, can be pressed against one another for torque transmission. The first piston side is acted on with operating pressure, and the second piston side is acted on with coolant pressure. A valve, by which the operating pressure can be set, and a device which makes a reaction of the coolant pressure on the operating pressure possible are provided. The device is designed as a hydraulic resistance cascade and is connected between coolant supply and coolant return lines of the friction elements. A return pressure line branches off in the center of the hydraulic resistance cascade and is connected to the valve.

Claims (26)

1. A clutch device for a motor vehicle, comprising:

friction elements around which coolant flows,

a piston by which the friction elements can be pressed against one another for torque transmission, a first piston side being acted on with operating pressure and a second piston side being acted on with coolant pressure,

a valve by which the operating pressure can be set, and

a device which makes reaction of the coolant pressure on the operating pressure possible,

wherein the device is a hydraulic resistance cascade and is connected between a coolant supply line and a coolant return line of the friction elements, and

wherein a return pressure line branching off in the center of the hydraulic resistance cascade is connected to the valve.

2. The clutch device as claimed in claim 1 , wherein the valve is a 3/3-way valve.

3. The clutch device as claimed in claim 2 , wherein the valve has a slide which is arranged axially displaceably within a longitudinal bore of a housing.

4. The clutch device as claimed in claim 3 , wherein the slide has, in an end region, a slide bore with a piston arranged therein, and wherein the bore communicates with a peripheral groove of the slide.

5. The clutch device as claimed in claim 4 , wherein the slide has an annular surface which can be acted on with the pressure from the return pressure line.

6. The clutch device as claimed in claim 3 , wherein the slide has an annular surface which can be acted on with the pressure from the return pressure line.

7. The clutch device as claimed in claim 2 , further comprising a pressure valve by which pressure in at least one of the coolant supply line and the coolant return line can be limited to a maximum value arranged in at least one of the coolant supply line and the coolant return line.

8. The clutch device as claimed in claim 1 , wherein the valve has a slide which is arranged axially displaceably within a longitudinal bore of a housing.

9. The clutch device as claimed in claim 8 , wherein the slide has, in an end region, a slide bore with a piston arranged therein, and wherein the bore communicates with a peripheral groove of the slide.

10. The clutch device as claimed in claim 9 , further comprising a pressure valve by which pressure in at least one of the coolant supply line and the coolant return line can be limited to a maximum value arranged in at least one of the coolant supply line and the coolant return line.

11. The clutch device as claimed in claim 8 , wherein the slide has an annular surface which can be acted on with the pressure from the return pressure line.

12. The clutch device as claimed in claim 11 , further comprising a pressure valve by which pressure in at least one of the coolant supply line and the coolant return line can be limited to a maximum value arranged in at least one of the coolant supply line and the coolant return line.

13. The clutch device as claimed in claim 8 , further comprising a pressure valve by which pressure in at least one of the coolant supply line and the coolant return line can be limited to a maximum value arranged in at least one of the coolant supply line and the coolant return line.

14. The clutch device as claimed in claim 1 , further comprising a pressure valve by which pressure in at least one of the coolant supply line and the coolant return line can be limited to a maximum value arranged in at least one of the coolant supply line and the coolant return line.

15. The clutch device as claimed in claim 14 , wherein the pressure valve is a valve by means of which the pressure in the coolant supply line can be reduced to a lubricating pressure level and can be limited to a maximum value is arranged in the coolant supply line.

16. The clutch device as claimed in claim 1 , wherein the coolant return line and the hydraulic resistance cascade meet at a connection point, wherein the connection point in turn communicates with a supply of a transmission lubrication system, and wherein a cooler is connected before the supply of the transmission lubrication system.

17. The clutch device as claimed in claim 1 , wherein a line to a cooler which is connected to a supply of a transmission lubrication system branches off from the coolant supply line before the hydraulic resistance cascade branches off.

18. The clutch device as claimed in claim 1 , wherein a cooler is connected into the coolant supply line before the hydraulic resistance cascade branches off, and wherein a line branching off, which is connected to a supply of a transmission lubrication system, is provided.

19. The clutch device as claimed in claim 1 , wherein the friction elements are components of a wet starting clutch.

20. A transmission for a motor vehicle comprising a clutch device as claimed in claim 1 .

Assignments (3)
CORRECTIVE ASSIGNMENT TO CORRECT THE APPLICATION NO. 10/567,810 PREVIOUSLY RECORDED ON REEL 020976 FRAME 0889. ASSIGNOR(S) HEREBY CONFIRMS THE CHANGE OF NAME. Recorded Jul 1, 2020
From: DAIMLERCHRYSLER AG
To: DAIMLER AG
Reel/Frame 053583/0493 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 5, 2008
From: KEMMNER, BENJAMIN; SCHAEFER, ALBRECHT
To: DAIMLER AG
Reel/Frame 021053/0935 →
CHANGE OF NAME Recorded May 14, 2008
From: DAIMLERCHRYSLER AG
To: DAIMLER AG
Reel/Frame 020976/0889 →