Planetary carrier with spring clutch

Patent metadata

Field	Value
Publication number	US-9772029-B2
Application number	US-201514795342-A
Country	US
Kind code	B2
Filing date	Jul 9, 2015
Priority date	Jul 9, 2015
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A planetary gear assembly comprising: a housing, which contains: a planetary carrier, a sun gear, at least one planetary gear, a ring gear, a coil spring; an input shaft; and an output shaft. The coil spring extends around at least a portion of the planetary carrier. The coil spring includes a first tang in communication with the ring gear and a second tang in communication with the housing. When torque is applied to the input shaft, the planetary carrier rotates within the coil spring in one or more driving directions so that torque is transferred to the output shaft. When no torque is applied to the input shaft and torque is applied to the output shaft, the coil spring constricts and provides sufficient contact force to the planetary carrier and housing to prevent the planetary carrier from moving relative to the housing in at least one of the driving directions.

First claim

What is claimed is:

1. A planetary gear assembly comprising:
a) a housing which contains:
(i) a planetary carrier;
(ii) a sun gear;
(iii) at least one planetary gear;
(iv) a ring gear; and
(v) a coil spring which extends around all or a portion of the planetary carrier;

b) an input shaft; and
c) an output shaft;
wherein the coil spring includes a first tang that is in communication with the ring gear and a second tang that is in communication with the housing;
wherein when torque is applied to the input shaft, the planetary carrier rotates within the coil spring in one or more driving directions so that torque is transferred to the output shaft;
wherein when no torque is applied to the input shaft and torque in one direction is applied to the output shaft, the coil spring constricts and provides sufficient contact force to the planetary carrier and to the housing to prevent the planetary carrier from moving relative to the housing in at least one of the one or more driving directions: and
wherein the housing includes a channel, the ring gear includes a projection engaged in the channel, and the channel limits a degree of rotation of the ring gear in at least one of the one or more driving directions.

2. The planetary gear assembly of claim 1 , wherein the coil spring is a helical torsion spring.

3. The planetary gear assembly of claim 1 , wherein when torque is applied to the input shaft in one of the one or more driving directions this results in rotation of the planetary carrier in a first direction and rotation of the ring gear in a direction opposing that of the planetary carrier is restricted by the projection contacting a first surface of the channel; and
wherein when torque is applied to the input shaft in another of the one or more driving directions this results in rotation of the planetary carrier in a second direction and rotation of the ring gear in a direction opposing that of the planetary carrier is restricted by the projection contacting a second surface of the channel.

4. The planetary gear assembly of claim l, wherein the ring gear includes a notch, the first tang of the coil spring is seated within the notch, and the notch can apply a force to the first tang of the coil spring in at least one of the one or more driving directions.

5. The planetary gear assembly of claim 4 , wherein when torque is applied to the input shaft in one of the one or more driving directions this results in rotation of the planetary carrier in a first direction and rotation of the ring gear in a direction opposing that of the planetary carrier is restricted by the projection contacting a first surface of the channel; and
wherein the first surface prevents the ring gear from rotating to a position in which the notch would apply force to the first tang of the coil spring.

6. The planetary gear assembly of claim 4 , wherein one of the one or more driving directions is a direction of torque applied to the input shaft which results in rotation of the planetary carrier in the direction that tends to contract the coil spring.

7. The planetary gear assembly of claim 6 , wherein when torque is applied to the input shaft in a direction which results in rotation of the planetary carrier in a direction that tends to contract the coil spring, rotation of the ring gear in a direction opposing that of the planetary carrier is restricted by the projection contacting a second surface of the channel.

8. The planetary gear assembly of claim 7 , wherein when torque is applied to the input shaft in a direction that results in rotation of the planetary carrier in a direction that tends to contract the coil spring, the notch applies force to the first tang in a direction tending to expand the coil spring so that the coil spring does not further contract about the planetary carrier.

9. The planetary gear assembly of claim 1 , wherein when no torque is applied to the input shaft and torque is applied to the output shaft in a direction of torque that tends to contract the coil spring, the coil spring contracts about the planetary carrier and a portion of the housing thereby restricting the planetary carrier from rotating further relative to the housing.

10. A brake system comprising:
a) a planetary gear assembly comprising:
(i) a housing which contains:
1) a planetary carrier;
2) a sun gear;
3) at least one planetary gear;
4) a ring gear; and
5) a coil spring which extends around all or a portion of the planetary carrier; the coil spring including a first tang that is in communication with the ring gear and a second tang that is in communication with the housing;

(ii) an input shaft; and
(iii) an output shaft;

b) at least one rotary to linear actuator in communication with the planetary gear assembly;
c) at least one torque multiplication assembly at least partially in communication with the input shaft or the output shaft of the planetary gear assembly;
wherein when torque is applied to the input shaft the planetary carrier rotates within the coil spring in one or more driving directions so that torque is transferred to the output shaft;
wherein when no torque is applied to the input shaft and torque in one direction is applied to the output shaft, the coil spring constricts and provides sufficient contact force to the planetary carrier and to the housing to prevent the planetary carrier from moving relative to the housing in at least one of the one or more driving directions;
wherein when torque is provided by the output shaft directly or indirectly to the rotary to linear actuator this results in movement of at least a portion of the rotary to linear actuator so that two or more brake shoes or brake pads respectively are moved to create a brake force or moved to release a brake force; and
wherein after a brake force is created and when no torque is applied to the input shaft, the coil spring constricts and applies sufficient force to the planetary carrier and the housing so that movement of the planetary carrier is prevented in at least one of the one or more driving directions.

11. The brake system of claim 10 , wherein the coil spring is a helical torsion spring.

12. The brake system of claim 10 , wherein the housing includes a channel, the ring gear includes a projection engaged in the channel, and the channel limits a degree of rotation of the ring gear in the one or more driving directions.

13. The brake system of claim 12 , wherein the ring gear includes a notch, the first tang is seated within the notch, and the notch can apply a force to the coil spring in at least one of the one or more driving directions.

14. The brake system of claim 13 , wherein when torque is applied to the input shaft in one of the one or more driving directions this results in rotation of the planetary carrier in a first direction and rotation of the ring gear in an a direction opposing that of the planetary carrier is restricted by the projection contacting a first surface of the channel; and
wherein the first surface prevents the ring gear from rotating to a position in which the notch would otherwise apply force to the coil spring; and
wherein when torque is applied to the input shaft in another of the one or more driving directions this results in rotation of the planetary carrier in a second direction and rotation of the ring gear in an a direction opposing that of the planetary carrier is restricted by the projection contacting a second surface of the channel.

15. The brake system of claim 13 , wherein when torque is applied to the input shaft in a direction resulting in rotation of the planetary carrier in a direction

Assignees

• Akebono Brake Ind

Inventors

• Thomas Carla

Classifications

• F16D2127/004

  direction-responsive · CPC title

• F16D51/22

  mechanically actuated · CPC title

• F16D2125/50

  with parallel non-stationary axes, e.g. planetary gearing · CPC title

• F16D65/22 Primary

  adapted for pressing members apart {, e.g. for drum brakes} · CPC title

• F16D65/18

  adapted for drawing members together {, e.g. for disc brakes} · CPC title