Shift by wire transmission shift control system with park release
View Patent ↗At least some implementations of a gear shift control system include first and second drive members, a drivetrain selectively driven by the first and second drive members and a retainer. The drivetrain includes a first input driven by the first drive member, a second input and an output coupled to and selectively driven by both the first input and the second input. The second drive member is coupled to the second input to drive the output through the second input during a second mode of operation to cause a transmission gear shift. The retainer is selectively coupled to the second input and movable between first and second positions to permit movement of the second input during the second mode of operation and prevent such movement during a first mode of operation.
1. A gear shift control system, comprising:
a first drive member;
a drivetrain including a first input driven by the first drive member during a first mode of operation to cause a transmission gear shift, a second input driven during a second mode of operation to cause a transmission gear shift and an output coupled to and selectively driven by both the first input and the second input, the output adapted to be coupled to a shift mechanism of the transmission;
a second drive member coupled to the second input to drive the output through the second input during said second mode of operation to cause a transmission gear shift; and
a retainer selectively coupled to the second input and manually movable between a first position wherein the retainer prevents movement of the second input during the first mode of operation and a second position wherein the retainer permits movement of the second input during the second mode of operation.
2. The system of claim 1 wherein the second drive element includes a drive gear coupled to the second input and the retainer includes at least one stop surface engaged by a stop in the first position to prevent rotation of the drive gear and wherein the retainer stop surface may be disengaged from the stop in the second position to permit rotation of the drive gear.
3. The system of claim 2 wherein the drive gear may be manually rotated.
4. The system of claim 2 wherein the drive gear may be rotated in a first direction to cause a transmission gear change toward or into a park gear and in a second direction to cause a transmission gear change away from or out of park gear.
5. The system of claim 2 wherein the drive gear and second input include meshed teeth.
6. The system of claim 2 wherein the first input, second input and the output are gears in a planetary gear set with the first input being one of a sun gear and a ring gear and the second input being the other of the sun gear and ring gear, and the second input includes teeth that are meshed with teeth of the drive gear.
7. The system of claim 6 wherein the second input is the ring gear and the teeth of the ring gear are formed in a periphery of the ring gear.
8. The system of claim 1 which also comprises a release associated with the retainer and manually movable from a first position in which the retainer holds the second input against movement and a second position wherein the retainer does not hold the second input against movement.
9. The system of claim 2 which also comprises a housing in which the drivetrain is received and wherein the stop is defined by the housing.
10. The system of claim 2 wherein the retainer is yieldably biased toward the first position, and movable axially relative to the stop and the second input.
11. The system of claim 2 which also comprises a limit surface adapted to limit movement of the second input during the second mode of operation.
12. The system of claim 11 wherein the limit surface is positioned so that when the limit surface is engaged by the second input the transmission is in a desired gear.
13. The system of claim 12 wherein the desired gear is park.
14. The system of claim 12 wherein the desired gear is not park.
15. The system of claim 14 which also comprises a second limit surface wherein the second limit surface corresponds to a position of the second input wherein the transmission is in park.
16. The system of claim 1 wherein the first drive member is electrically operated and the second drive member is not electrically operated.
17. The system of claim 8 wherein the retainer includes a torsion spring having a movable leg and the release is manually movable to the second position wherein the movable leg is displaced.
18. The system of claim 17 wherein the second drive element includes a spring that biases the second input for movement and upon movement of the release to the second position the second drive element moves the second input.
19. A gear shift control system, comprising:
a first drive member including an electric motor;
an output adapted to be coupled to a vehicle transmission and to the first drive member to be driven for rotation by the first drive member;
a planetary gear set coupled to the first drive member and the output, and having three intermeshed gear elements including a ring gear, a sun gear and at least one planet gear, where a first gear element is coupled to the first drive member and is driven for rotation by the first drive member, and a second gear element is coupled to the output shaft for rotation with the output shaft;
a second drive member coupled to a third gear element to drive the output shaft through the third gear element, wherein during a first mode of operation the transmission is shifted between park and other gears by causing the first drive member to rotate the output through the second gear element and the first gear element when a transmission gear shift is desired, and during a second mode of operation, the transmission is shifted by the second drive member which drives the output through the third gear element and first gear element, and wherein the second drive member includes a drive gear with teeth and the third gear element includes teeth meshed with the drive gear teeth so that rotation of the drive gear causes rotation of the third gear element.
20. The system of claim 19 which also includes at least one stop surface with which the retainer is selectively engaged to prevent rotation of the drive gear, and wherein the drive gear teeth are engaged with teeth of the ring gear when the drive gear is engaged with the stop surface to prevent rotation of the third gear element.
21. The system of claim 19 wherein the drive gear may be rotated in a first direction to cause a transmission gear change toward or into a park gear and in a second direction to cause a transmission gear change away from or out of park gear.
22. The system of claim 19 wherein the second drive member includes a spring that rotates the third gear element when the retainer is moved to the second position.
23. The system of claim 19 wherein the retainer is coupled to the drive gear and includes a stop surface that when engaged by a stop, prevents rotation of the drive gear, and wherein the retainer and drive gear are movable relative to the stop to permit rotation of the drive gear when the retainer is in the second position.
24. The system of claim 23 wherein the drive gear is rotated about an axis and the retainer and drive gear move axially when the retainer is moved between the first and second positions.