Speed differential-dependent hydraulic clutch with a control valve

• US 20040132581A1
• Filed: 03/05/2004
• Published: 07/08/2004
• Est. Priority Date: 04/02/2001
• Status: Active Grant

• Current Assignee: Magna Steyr Powertrain AG & Co., KG.
• Original Assignee: Magna Steyr Powertrain AG & Co., KG.
• Inventors: Gratzer, Franz, Schaffernak, Robert
• Granted Patent: US 7,077,256 B2
• Time in Patent Office: Days
• US Class Current: 477/166
• CPC Class Codes: F16D 25/0638 with more than two discs, e.g. multiple lamellae
• CPC Class Codes: F16D 43/284 controlled by angular speed

Abstract

A speed-difference-dependent hydraulic clutch comprises a drive housing (11), which rotates in a housing (20), a first shaft (21) which can be connected in a rotationally fixed manner to the drive housing, a second shaft (22) which is connected in a rotationally fixed manner to the drive housing, and furthermore a hydrostatic displacement machine (1), a friction clutch (12) for connecting the first shaft (21) to the drive housing (11), and a piston (10) for acting on the friction clutch (12), the drive housing (11) having a pressure space (9) and where a pressure is produced in the pressure space (9) when a difference in speed occurs in the pressure space (9), this pressure giving rise to action upon the friction clutch (12), and a passage (13) leading from the pressure space to a control valve which opens up the route to a space of lower pressure in a controlled manner. In order to make possible a sensitive, precise and rapid control and adaptation of the characteristic with as little outlay as possible, the control valve (14) is arranged in the drive housing (11) and/or, in the second shaft (22), which is connected in a rotationally fixed manner to the drive housing (11), is arranged coaxially with said shaft, and has a control element (52) which can be displaced in the direction of the axis and is actuated by an actuator (59, 61, 62) which is fixed on the housing.

Claims

1. A speed-difference-dependent hydraulic clutch, comprising a drive housing (11), which rotates in a housing (20) that is fixed in space and forms a reservoir for a working fluid, a first shaft (21) which can be connected in a rotationally fixed manner to the drive housing, a second shaft (22) which is connected in a rotationally fixed manner to the drive housing, and furthermore a hydrostatic displacement machine (1), a friction clutch (12) for connecting the first shaft (21) to the drive housing (11) and a piston (10) for acting on the friction clutch (12), which are accommodated in the drive housing, the drive housing (11) having a pressure space (9), and where a pressure is produced in the pressure space (9) when a difference occurs between the speed of the drive housing (11) and that of the second shaft (22), this pressure giving rise to action upon the friction clutch (12), and a passage (13) leading from the pressure space to a control valve (14) which opens up the route to a space of lower pressure in a controlled manner, characterized in that the control valve (14) is arranged in the drive housing (11) and/or, in the second shaft (22), which is connected in a rotationally fixed manner to the drive housing (11), is arranged coaxially with said shaft, and has a control element (52) which can be displaced in the direction of the axis and is actuated by an actuator (59, 61, 62;

74) which is fixed on the housing.

2. The speed-difference-dependent hydraulic clutch as claimed in claim 1, characterized in that the control valve (14) comprises the control element (52) and a valve body (44) having a cylindrical surface (47) which is coaxial with the axis of rotation and is intended for the control element (52), the coaxial cylindrical surface (47) being open into the interior of the drive housing (11) and the passage (13) leading from the pressure space (9) into an inlet opening (46) on the cylindrical surface (47).

3. The speed-difference-dependent hydraulic clutch as claimed in claim 2, characterized in that the control element (52) is a cylindrical pin which is loaded in the opening direction of the control valve (14) by a compression spring (53).

4. The speed-difference-dependent hydraulic clutch as claimed in claim 1, characterized in that the control valve (14) is a proportional valve which is controlled as a function of operating states.

5. The speed-difference-dependent hydraulic clutch as claimed in claim 2, characterized in that an actuator (60, 61, 62;

74) which is arranged outside the second shaft (22), which is connected in a rotationally fixed manner to the drive housing (11), is mounted fixed on the housing and acts on the control element (52) is provided.

6. The speed-difference-dependent hydraulic clutch as claimed in claim 5, characterized in that the actuator (60, 61, 62) interacts with a selector sleeve (56) which surrounds the second shaft (22), rotates together with it and can be displaced in the axial direction, in that a rod (55) which passes through the selector sleeve (56) and the second shaft (22) and comes into contact with the control element (52) is provided, the second shaft (22) having a slot (54) for the rod (55) to pass through.

7. The speed-difference-dependent hydraulic clutch as claimed in claim 5, characterized in that the actuator (74) is a solenoid (74) which surrounds the second shaft (22) and acts on the control element (52) through the second shaft (22), with a magnetically neutral region (73) of the shaft (22) preventing a magnetic short circuit.

8. The speed-difference-dependent hydraulic clutch as claimed in claim 7, characterized in that the valve body (44) is inserted into a central hole (48) of the drive housing (11) and the control element (52) is a pin with an armature (72).