PLANETARY DIFFERENTIAL AND SPEED SERVO

• US 3,768,715 A
• Filed: 05/01/1972
• Issued: 10/30/1973
• Est. Priority Date: 05/01/1972
• Status: Expired due to Term

• Current Assignee: Stanley D. Tout
• Original Assignee: Stanley D. Tout
• Inventors: Tout, Stanley D.
• Primary Examiner(s): Schacher, Richard A.
• Application Number:
  US05/249,046
• Time in Patent Office: 547 Days
• Field of Search: 226/31,44,40 74/797,801,798,697,796
• US Class Current: 226/40
• CPC Class Codes: F16H 13/08 with balls or with rollers acting in a similar manner
• CPC Class Codes: F16H 3/724 using external powered electric machines

Abstract

A planetary differential employs a longitudinal shaft having a restricted portion at least two balls directly engaging the longitudinal shaft at said restricted portion forming an inner race. The differential includes further an outer race having a taper engaged by the balls and a cage for the balls. A first rotary input is provided to one of the inner race, outer race, and cage. A secondary rotary input is provided to another of the inner race, outer race, and cage. A rotary output is provided to yet another of the inner race, outer race, and cage. The inner race and outer race are mounted for rotary movement. A servo system, including the planetary differential, is also disclosed.

Claims

1. A planetary differential comprising in combination:

a longitudinal shaft having a restricted portion;

at least two balls directly engaging said longitudinal shaft at said restricted portion forming an inner race for said balls;

an outer race for said balls having a taper engaged by said balls;

a cage for said balls;

first rotary input means connected to one of said inner race, outer race and cage;

second rotary input means connected to another of said inner race, outer race and cage;

rotary output means connected to yet another of said inner race, outer race and cage; and

means for mounting said races for rotary movement.

2. A planetary differential as claimed in claim 1, wherein:

said first rotary input means are connected to said inner race;

said second rotary input means are connected to said cage; and

said rotary output means are connected to said outer race.

3. A planetary differential as claimed in claim 1, wherein:

said planetary differential has only two of said balls.

4. A planetary differential as claimed in claim 1, wherein:

said restricted shaft portion is curved and has a radius larger than the radius of each of said balls.

5. A planetary differential as claimed in claim 1, wherein:

said shaft has a free end and said outer race has a cavity forming a bearing for said free shaft end.

6. A planetary differential as claimed in claim 5, including in said combination:

means for biasing said shaft in an axial direction toward said bearing in the outer race.

7. A planetary differential as claimed in claim 6, wherein:

said restricted shaft portion is curved and has a radius larger than the radius of each of said balls.

8. A planetary differential as claimed in claim 7, wherein:

said planetary differential has only two of said balls.

9. A planetary differential as claimed in claim 1, including said combination:

a drive pulley integral with said cage.

10. An apparatus for controllably moving an object, comprising in combination:

a longitudinal shaft having a restricted portion;

at least two balls directly engaging said longitudinal shaft at said restricted portion forming an inneR race for said balls;

an outer race for said balls having a taper engaged by said balls;

a cage for said balls;

means for mounting said races for rotary movement;

first driving means connected to one of said inner race, outer race and cage;

second driving means connected to another of said inner race, outer race and cage;

means for coupling said object for movement to yet another of said inner race, outer race and cage; and

means connected to said first driving means for selectively energizing said first driving means.

11. An apparatus as claimed in claim 10, wherein:

said object is a web of material; and

said means for selectively energizing said first driving means include means for sensing excessive and insufficient movement of said web, and means connected to said sensing means and to said first driving means for selectively energizing said first driving means in a first sense and in a second sense, respectively, in response to sensing of excessive and insufficient web movement.

12. An apparatus as claimed in claim 11, wherein:

said sensing means include means for sensing the size of a loop of said web.

13. An apparatus as claimed in claim 10, wherein:

said first driving means are connected to said inner race;

said second driving means are connected to said cage; and

said coupling means are connected to said outer race.

14. An apparatus as claimed in claim 10, wherein:

said planetary differential has only two of said balls.

15. An apparatus as claimed in claim 10, wherein:

said restricted shaft portion is curved and has a radius larger than the radius of each of said balls.

16. An apparatus as claimed in claim 10, wherein:

said shaft has a free end and said outer race has a cavity forming a bearing for said free shaft end.

17. An apparatus as claimed in claim 16, including in said combination:

means for biasing said shaft in an axial direction toward said bearing in the outer race.

18. An apparatus as claimed in claim 17, wherein:

said restricted shaft portion is curved and has a radius larger than the radius of each of said balls.

19. An apparatus as claimed in claim 18, wherein:

said planetary differential has only two of said balls.

20. An apparatus as claimed in claim 10, including in said combination:

a drive pulley integral with said cage.