| 摘要 |
An actuator of an electric parking brake system includes a motor, an output member, and a transmission device. The transmission device includes a housing, a self-locking unit and a transmission unit. The self-locking unit includes a fixed sleeve, and a driving member, a driven member and a lock holder that are rotatable with respect to the sleeve. The lock holder supports lock elements arranged to prevent the driven member from turning unless it is driven by the driving member. A planetary gear unit may be provided as part of the transmission device. |
| 主权项 |
1. An actuator of an electric parking brake system, comprising:
a motor; an output member; and a transmission device connected between the motor and the output member, the transmission device comprising a housing, and a self-locking unit and a transmission unit that are received in the housing, the self-locking unit comprising: a sleeve fixed with respect to the housing, a driving member, a driven member and a holder, all arranged coaxially with the sleeve and are rotatable with respect to the sleeve, the driving member and the driven member having transmission components configured to engage with each other, the holder being rotatably sleeved on the sleeve and located in the driven member, and the holder is provided with a plurality of lock elements, wherein each of the lock elements extend beyond the holder in a radial direction, and is located between a radially inner wall surface of the driven member and a radially outer wall surface of the sleeve, a distance between the inner wall surface of the driven member and the outer wall surface of the sleeve is configured to gradually decrease from the center of the inner wall surface of the driven member to two sides of the inner wall surface of the driven member, in a circumferential direction, a greatest distance is greater than a diameter of the lock element, and a smallest distance is smaller than the diameter of the lock element, whereby when the driving member rotates the driven member, the holder is rotated by the driving member to maintain the lock element located approximately at a position corresponding to the greatest distance; and when the driven member rotates without the driving member, the inner wall surface of the driven member rotates with respect to the holder to allow the lock element to move towards a position corresponding to the smallest distance, to stop further rotation of the driven member with respect to the sleeve. |
