The present invention relates to an actuator for an electronic parking brake. The actuator for an electronic parking brake of the present invention includes a motor configured to provide a driving force, and a housing in which a gear unit for transmitting the driving force of the motor is mounted. The gear unit includes a worm gear to which the driving force of the motor is transmitted, a plurality of planetary gears coupled to an outer side of a sun gear which is provided in the worm gear, and a carrier configured to rotatably support the planetary gears, have the same rotation shaft as a rotation shaft of the sun gear, and output the driving force. A carrier accommodation unit coupled to outer sides of the planetary gears is formed in the housing.

The present invention relates to an actuator for an electronic parking brake. The actuator for an electronic parking brake of the present invention includes a motor configured to provide a driving force, and a housing in which a gear unit for transmitting the driving force of the motor is mounted. The gear unit includes a worm gear to which the driving force of the motor is transmitted, a plurality of planetary gears coupled to an outer side of a sun gear which is provided in the worm gear, and a carrier configured to rotatably support the planetary gears, have the same rotation shaft as a rotation shaft of the sun gear, and output the driving force. A carrier accommodation unit coupled to outer sides of the planetary gears is formed in the housing.

The subject matter of this specification can be embodied in, among other things, an actuator that includes a worm drive assembly having a worm shaft, and a worm wheel configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the inner perimeter, and an epicyclic gear assembly having a sun gear and a planet gear engaged with the sun gear and the second collection of gear teeth.

The subject matter of this specification can be embodied in, among other things, an actuator that includes a worm drive assembly having a worm shaft, and a worm wheel configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the inner perimeter, and an epicyclic gear assembly having a sun gear and a planet gear engaged with the sun gear and the second collection of gear teeth.

A planetary gearset (6) has a sun gear (10) connected rotationally fixedly to an input shaft (8), a carrier (15) that carries planetary gears (11) and is connected rotationally fixedly to an output shaft (16), and a ring gear (14) fixedly connected to a housing (4) that encloses the planetary gearset (6). To reduce the noise emission from the planetary gearset with as little structural complexity as possible without reducing its efficiency due to pressure rings that are guided and slide against the planetary gears and the carrier, the sun gear (10), the planetary gears (11) and the ring gear (14) are provided with helical teeth and the input shaft (8) is at least indirectly supported on the housing (4), in both axial directions, by way of a single roller bearing (20).

A planetary gearset (6) has a sun gear (10) connected rotationally fixedly to an input shaft (8), a carrier (15) that carries planetary gears (11) and is connected rotationally fixedly to an output shaft (16), and a ring gear (14) fixedly connected to a housing (4) that encloses the planetary gearset (6). To reduce the noise emission from the planetary gearset with as little structural complexity as possible without reducing its efficiency due to pressure rings that are guided and slide against the planetary gears and the carrier, the sun gear (10), the planetary gears (11) and the ring gear (14) are provided with helical teeth and the input shaft (8) is at least indirectly supported on the housing (4), in both axial directions, by way of a single roller bearing (20).

A positively-engaged infinitely-variable transmission (PE-IVT) system employs a gear assembly including a first helical gear and a second helical gear meshed with the first helical gear. The first helical gear is divided into a plurality of gear segments that can individually move axially along a spline shaft. The PE-IVT system further includes a swashplate configured to constrain the axial motion of the plurality of gear segments. In some embodiments, the system further includes one or more thread-aligners configured to axially align a gear segment with one or more additional gear segments. In some embodiments, the second helical gear is also divided into a plurality of gear segments.

A positively-engaged infinitely-variable transmission (PE-IVT) system employs a gear assembly including a first helical gear and a second helical gear meshed with the first helical gear. The first helical gear is divided into a plurality of gear segments that can individually move axially along a spline shaft. The PE-IVT system further includes a swashplate configured to constrain the axial motion of the plurality of gear segments. In some embodiments, the system further includes one or more thread-aligners configured to axially align a gear segment with one or more additional gear segments. In some embodiments, the second helical gear is also divided into a plurality of gear segments.

The subject matter of this specification can be embodied in, among other things, an actuator that includes a worm drive assembly having a worm shaft, and a worm wheel configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the inner perimeter, and an epicyclic gear assembly having a sun gear and a planet gear engaged with the sun gear and the second collection of gear teeth.

The subject matter of this specification can be embodied in, among other things, an actuator that includes a worm drive assembly having a worm shaft, and a worm wheel configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the inner perimeter, and an epicyclic gear assembly having a sun gear and a planet gear engaged with the sun gear and the second collection of gear teeth.