Double clutch drive with position maintaining function

A double clutch drive comprising:

• a first and second clutch;
• a first electronically activated hydraulic device for closing/opening the first clutch;
• a second electronically activated hydraulic device for closing/opening the second clutch;
• a position-holding hydraulic device to which position signals corresponding to a momentary shifted position of the first and second clutch are sent through a first and a second hydraulic line, and which is connected through hydraulic control lines with the first and second hydraulic device,
• wherein the position-holding hydraulic device operates the first and the second hydraulic device such that, in the event of the failure of electronic control, a clutch that was slipping before the failure is opened.

A double clutch drive comprising:

• a first and a second clutch;
• a first electronically activated hydraulic device for closing/opening the first clutch;
• a second electronically activated hydraulic device for closing/opening the second clutch;
• a position-holding hydraulic device to which position signals corresponding to a momentary shifted position of the first and second clutch are sent through a first and a second hydraulic line, and which is connected through hydraulic control lines with the first and second hydraulic device,
• wherein the position-holding hydraulic device operates the first and the second hydraulic device such that, in case of the failure of electronic control, a clutch that was slipping before the failure is closed.

A double clutch drive comprising:

• a first and a second clutch;
• a first electronically activated hydraulic device for closing/opening the first clutch;
• a second electronically activated hydraulic device for closing/opening the second clutch;
• a position-holding hydraulic device to which position signals corresponding to a momentary shifted position of the first and second clutch are sent through a first and a second hydraulic line, and which is connected through hydraulic control lines with the first and second hydraulic device,
• wherein the position-holding hydraulic device operates the first and the second hydraulic device and, in the event of the failure of electronic control, a clutch that was slipping before the failure is closed only if a supply pressure is present at a supply inlet of the position-holding hydraulic device.

A method for making a double clutch drive, comprising:

• providing a first and a second clutch;
• providing a first electronically activated hydraulic device for closing/opening the first clutch;
• providing a second electronically activated hydraulic device for closing/opening the second clutch;
• providing a position-holding hydraulic device to which position signals corresponding to a momentary shifted position of the first and second clutch are sent through a first and a second hydraulic line, and which is connected through hydraulic control lines with the first and second hydraulic device, wherein the position-holding hydraulic device operates, in many positions of the clutches, the first and the second hydraulic device such that positions of the clutches immediately before a failure of electronic control remain sustained.