Torque transmission device

A torque transmitting unit for inclusion in the drive train of a motor vehicle. The unit transmits torque between an engine having an output shaft and a transmission having at least one input shaft that is drivingly coupled with the engine by a clutch and a intermediate torsional vibration damper. The torque transmitting unit includes primary and secondary flywheel masses that are mounted on the transmission input shaft along with the clutch.

BACKGROUND OF THE INVENTION

The present invention relates to a torque transmission device in the drive train of a motor vehicle for the transmission of torque between a drive unit, in particular an internal combustion engine having an output shaft, in particular a crankshaft, and a transmission having at least one transmission input shaft that can be coupled to the output shaft of the drive unit by a clutch. A torsional vibration damper including a primary flywheel mass and a secondary flywheel mass is interposed between the drive unit and the transmission.

An object of the present invention is to provide a torque transmission device in the drive train of a motor vehicle for the transmission of torque between a drive unit having an output shaft, and a transmission having at least one transmission input shaft that is coupled to the output shaft of the drive unit by a clutch. The torque transmitting unit includes a torsional vibration damper interposed between the drive unit and the transmission and including a primary flywheel mass and a secondary flywheel mass, and which is simply constructed and is capable of being manufactured economically.

SUMMARY OF THE INVENTION

The object of the invention is achieved in the case of a torque transmission device in the power train of a motor vehicle for transmitting torque between a drive unit, in particular an internal combustion engine, having an output shaft, in particular a crankshaft, and a transmission having at least one transmission input shaft that can be coupled to the output shaft of the drive unit with the aid of a clutch. A torsional vibration damper is interposed between the engine and the transmission and includes a primary flywheel mass and a secondary flywheel mass. The primary flywheel mass and the secondary flywheel mass of the torsional vibration damper are mounted together with the clutch on the transmission input shaft. Preferably, a bearing, such as a roller bearing, is situated radially inside of and overlapping in the axial direction an output flange of the torsional vibration damper.

A preferred exemplary embodiment of the torsional vibration damper is characterized in that the primary flywheel mass is linked through a cup-shaped carrier plate to a sheet metal drive plate, which is attached to the output shaft of the drive unit. The cup-shaped carrier plate permits a greater distance between the drive unit and the transmission in the axial direction.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the primary flywheel mass and the carrier plate are attached to an annular connecting element having two end faces. Preferably, the primary flywheel mass and the carrier plate are attached to the connecting element by rivet fastening elements.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the primary flywheel mass is attached radially inwardly on the end face of the connecting element that faces the transmission. The primary flywheel mass has essentially the shape of an annular disk.

Another preferred exemplary embodiment of the torque transmission device is characterized in that radially outwardly of the end face of the connecting element that faces the transmission, a step is provided to receive a radially inner circumferential rim of the primary flywheel mass. That serves to simplify assembly.

Another preferred exemplary embodiment of the torque transmission device is characterized in that a step is provided radially inwardly on the end face of the connecting element that faces the transmission. That step makes it possible to check the torsion characteristic of the torsional vibration damper prior to assembly and during manufacturing.

Another preferred exemplary embodiment of the torque transfer device is characterized in that a centering projection is provided radially inwardly on the connecting element. The centering projection serves during assembly to pre-center the connecting element on a bearing hub that is connected to the output shaft of the drive unit.

Another preferred exemplary embodiment of the torque transmission device is characterized in that radially outwardly of the end face of the connecting element that faces away from the transmission, a step is provided to receive a radially inner circumferential rim of the carrier plate. That serves to simplify assembly.

Another preferred exemplary embodiment of the torque transmission device is characterized in that on its radially inner side and on its radially outer side the carrier plate has an essentially annular disk-shaped attachment flange. The radially outer attachment flange serves to attach the carrier plate to a drive plate, which, in turn, is attached radially inwardly to the output shaft of the drive unit.

Another preferred exemplary embodiment of the torque transmission device is characterized in that the two attachment flanges of the carrier plate are spaced from each other in the axial direction. Because of the axial spacing between the attachment flanges, the axial distance between the drive unit and the transmission can be varied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Part of a power train1of a motor vehicle is shown inFIG. 1. Situated between a drive unit3, in particular an internal combustion engine from which a crankshaft4extends, and a transmission5, is a clutch6. Connected between drive unit3and clutch6is a torsional vibration damper8. The torsional vibration damper8is preferably a damped flywheel. The crankshaft4of internal combustion engine3is rigidly connected through threaded connections9to a drive plate10, which has essentially the form of an annular disk extending in the radial direction. The drive plate10is also referred to as a flexplate. A starter ring gear12is provided radially outwardly on the drive plate10.

An attachment flange16of a cup-shaped carrier plate18is attached to the radial outer circumferential area of the drive plate10by threaded fasteners14. Radially inwardly the carrier plate18has an attachment flange19. The attachment flange19rests on a step20that is formed on an end face of a connecting element22that faces away from the transmission. The connecting element22has the form of an annulus23, on which a circular centering projection24extends radially inwardly. The centering projection24is in contact with a bearing hub25, which extends from the crankshaft4of the drive unit3toward the transmission5.

On the end face of connecting element22that faces the transmission5a step26is formed, which serves to receive an attachment flange28. Attachment flange28is secured together with attachment flange19to connecting element22by rivet fastening elements29. Attachment flange28is part of a primary flywheel mass31of an input part32of torsional vibration damper8. Input part32of torsional vibration damper8has essentially the form of a radially extending annular disk that forms a radially outer torsional vibration damper retainer34. At least partially incorporated into torsional vibration damper retainer34is at least one energy storage device, in particular a spring35. The spring35is engaged by an output part37, also known as an output flange, of the torsional vibration damper8.

A secondary flywheel mass42of the torsional vibration damper8is attached to the output part37by rivet fastening elements39. The secondary flywheel mass42is connected radially inwardly to an integral hub44. The hub44of the secondary flywheel mass42is rotatably supported on a transmission input shaft50of transmission5by a roller bearing46. The roller bearing46is preferably a ball bearing.

Radially inwardly on the end face of the connecting element22that faces the transmission5is a step52that is used prior to assembly of torsional vibration damper8for rotatable support of the hub44. An axial thrust ring54is incorporated into the step52for that purpose. The hub44comes to rest against the axial thrust ring54prior to assembly in order to measure the torsion characteristic of the torsional vibration damper8during production. In the assembled state of the torsional vibration damper8, the step52on the connecting element22has no function.