United States Patent
US Patent 7992459: Shifting claw transmission and shifting method…
US 7992459 · granted 2011-08-09
Abstract
In a shifting claw transmission for a motor vehicle including a main shaft and a countershaft and an electric motor for rotating the countershaft or being rotated thereby with freely rotatable gear wheels supported on the counter shaft and engageable with the countershaft by claw engagement structures, the speed of the countershaft is adjustable by the electric motor to be close to, but somewhat different from, the speed of the freely rotatable gear wheels to be engaged in order to facilitate shifting but avoid a tooth-on-tooth problem which would inhibit shifting.
| Patent Number | 7992459 |
|---|---|
| Title | Shifting claw transmission and shifting method therefor |
| Filed | 2008-03-13 |
| Granted | 2011-08-09 |
| Inventor(s) | Ludwig, Sager; Frank |
| Assignee | Daimler AG |
| CPC Classification | F16H 59/38, F16H 3/38 |
| Number of Claims | 45 |
Abstract
In a shifting claw transmission for a motor vehicle including a main shaft and a countershaft and an electric motor for rotating the countershaft or being rotated thereby with freely rotatable gear wheels supported on the counter shaft and engageable with the countershaft by claw engagement structures, the speed of the countershaft is adjustable by the electric motor to be close to, but somewhat different from, the speed of the freely rotatable gear wheels to be engaged in order to facilitate shifting but avoid a tooth-on-tooth problem which would inhibit shifting.
Claim 1
A shifting claw transmission (19) for a motor vehicle, comprising a main shaft (29) and a counter shaft (22), an electric motor (M) operatively connected to thecountershaft (22), said countershaft (22) being fitted with countershaft gearwheels (20b, 21b, 23, 24, 25) which mesh with main shaft gearwheels (20c, 21c, 26, 27, 28) of the main shaft (29), said gearwheels (20b, 21b, 23, 24, 25, 20c, 21c, 26, 27, 28)being one of fixed gear wheels and freely rotating gear wheels, the freely rotating gear wheels being provided with shifting claw structures for coupling them in a rotationally fixed fashion to the respective shaft (22 or 29) on which the respectivefreely rotating gear wheels are disposed, and control means (49) for controlling operation of the electric motor (M) for rotating the countershaft (22) so as to establish relative movement between the countershaft (22) and a gear wheel to be engaged inorder to avoid a tooth-on-tooth position of the shifting claws which would prevent engagement of the respective shifting claw structure.
Claims
45 totalA shifting claw transmission (19) for a motor vehicle, comprising a main shaft (29) and a counter shaft (22), an electric motor (M) operatively connected to thecountershaft (22), said countershaft (22) being fitted with countershaft gearwheels (20b, 21b, 23, 24, 25) which mesh with main shaft gearwheels (20c, 21c, 26, 27, 28) of the main shaft (29), said gearwheels (20b, 21b, 23, 24, 25, 20c, 21c, 26, 27, 28)being one of fixed gear wheels and freely rotating gear wheels, the freely rotating gear wheels being provided with shifting claw structures for coupling them in a rotationally fixed fashion to the respective shaft (22 or 29) on which the respectivefreely rotating gear wheels are disposed, and control means (49) for controlling operation of the electric motor (M) for rotating the countershaft (22) so as to establish relative movement between the countershaft (22) and a gear wheel to be engaged inorder to avoid a tooth-on-tooth position of the shifting claws which would prevent engagement of the respective shifting claw structure.