Drive train having clutch activation for overcoming the backlash of the drive train before start-up

• US 8,584,545 B2
• Filed: 12/20/2011
• Issued: 11/19/2013
• Est. Priority Date: 06/25/2009
• Status: Expired due to Fees

• Current Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Inventors: Reuschel, Michael
• Primary Examiner(s): Ho, Ha D
• Assistant Examiner(s): Agendia, Jude
• Application Number:
  US13/331,454
• Publication Number:
  US 20120160046A1
• Time in Patent Office: 700 Days
• Field of Search: 744/09, 744/40, 744/115, 744/06, 744/11, 744/12.R, 744/21.A, 475/331
• US Class Current: 74/409
• CPC Class Codes: F16D 2500/10412 Transmission line of a vehicle
• CPC Class Codes: F16D 2500/1045 Friction clutch
• CPC Class Codes: F16D 2500/3067 Speed of the engine
• CPC Class Codes: F16D 2500/30816 Speed of the input shaft
• CPC Class Codes: F16D 2500/30825 Speed of the output shaft
• CPC Class Codes: F16D 2500/50623 Preventing transmission load change
• CPC Class Codes: F16D 48/08 Regulating clutch take-up on starting
• CPC Class Codes: F16H 2312/022 Preparing to drive off
• CPC Class Codes: F16H 61/68 specially adapted for stepped gearings
• CPC Class Codes: Y10T 74/19623 Backlash take-up

Abstract

A drive train for a motor vehicle, including a drive unit having a drive shaft and a transmission having a transmission input shaft and a plurality of gears, of which at least one is used as a starting gear for the motor vehicle, and having a friction clutch, which is arranged between the crankshaft and the transmission input shaft and is actuated in an automated manner. In order to prevent start-up noise caused by backlashes in the motor vehicle, a backlash present in the transmission is compensated by applying a small compensating torque set at the friction clutch to the transmission input shaft while the starting gear is engaged before start up.

Claims

1. A drive train for a motor vehicle, comprising a drive unit having:

a drive shaft; and

,

a transmission having a transmission input shaft and a plurality of gears, of which at least one is used as a starting gear for the motor vehicle, and having a friction clutch, which is arranged between the crankshaft and the transmission input shaft and is actuated in an automated manner, wherein a rotation clearance present in the transmission is compensated by applying a small compensating torque set at the friction clutch to the transmission input shaft while the starting gear is engaged before start up.

2. The drive train according to claim 1, wherein the compensation torque is smaller than a startup torque required for moving the motor vehicle.

3. The drive train according to claim 1, wherein the compensation torque required for compensating the rotation clearance is learned during operations of the drive train.

4. The drive train according to claim 1, wherein:

the transmission includes an output shaft; and

the rotation clearance is determined by comparing a speed of the transmission input shaft with a speed of the transmission output shaft.

5. The drive train according to claim 4, wherein a respective compensation torque is associated with the determined rotation clearance.

6. The drive train according to claim 1, the compensation torque is configured as a function of the startup gear used.

7. The drive train according to claim 1, wherein the rotation clearance is compensated when the motor vehicle is standing still and a brake of the motor vehicle is actuated.

8. A method for actuating a drive train for a motor vehicle including a drive unit having a drive shaft and a transmission having a transmission input shaft and a plurality of gears, of which at least one is used as a starting gear for the motor vehicle, and having a friction clutch, which is arranged between the crankshaft and the transmission input shaft and is actuated in an automated manner, the method comprising:

compensating a rotation clearance present in the transmission by applying a small compensating torque set at the friction clutch to the transmission input shaft while the starting gear is engaged before start up, wherein;

compensating the rotation clearance includes compensating the rotation clearance when the motor vehicle is standing still and a brake of the motor vehicle is actuated.

9. A drive train for a motor vehicle, comprising a drive unit having:

a drive shaft; and

,

a transmission including an input shaft, an output shaft, a plurality of gears, and a friction clutch, wherein;

a gear from the plurality of gears is used as a starting gear for the motor vehicle;

the friction clutch is arranged between the crankshaft and the transmission input shaft and is actuated in an automated manner;

a rotation clearance is present in the transmission;

the rotation clearance is determined by comparing a speed of the transmission input shaft with a speed of the transmission output shaft; and

the rotation clearance is compensated by applying a small compensating torque set at the friction clutch to the transmission input shaft while the starting gear is engaged before start up.