Continuously variable transmission

• US 7,169,076 B2
• Filed: 01/05/2005
• Issued: 01/30/2007
• Est. Priority Date: 02/28/2003
• Status: Active Grant

• Current Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Original Assignee: Fallbrook Technologies Incorporated
• Inventors: Allen, David J., Smithson, Robert A., Miller, Donald C.
• Primary Examiner(s): Wright; Dirk
• Application Number:
  US11/030,535
• Publication Number:
  US 20050124456A1
• Time in Patent Office: 755 Days
• Field of Search: 475/214, 475/215, 476/37, 476/38
• US Class Current: 476/38
• CPC Class Codes: B62M 11/04 of changeable ratio
• CPC Class Codes: B62M 11/14 with planetary gears
• CPC Class Codes: B62M 9/08 involving eccentrically- mounted or elliptically-shaped driving or driven wheel; with expansible driving or driven wheel
• CPC Class Codes: F16H 15/28 with external friction surface
• CPC Class Codes: F16H 15/40 in which two members co-operative by means of balls, or rollers of uniform effective diameter, not mounted on shafts
• CPC Class Codes: F16H 15/50 Gearings providing a continuous range of gear ratios
• CPC Class Codes: F16H 15/503 in which two members co-operate by means of balls or rollers of uniform effective diameter, not mounted on shafts
• CPC Class Codes: F16H 15/52 in which a member of uniform effective diameter mounted on a shaft may co-operate with different parts of another member
• CPC Class Codes: F16H 2037/088 Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
• CPC Class Codes: F16H 2037/101 Power split variators with one differential at each end of the CVT
• CPC Class Codes: F16H 37/084 at least one power path being a continuously variable transmission, i.e. CVT
• CPC Class Codes: F16H 37/0853 CVT using friction between rotary members having a first member of uniform effective diameter cooperating with different parts of a second member
• CPC Class Codes: F16H 37/086 CVT using two coaxial friction members cooperating with at least one intermediate friction member
• CPC Class Codes: F16H 61/6649 characterised by the means for controlling the torque transmitting capability of the gearing
• CPC Class Codes: F16H 63/067 mechanical actuating means
• CPC Class Codes: Y10T 29/49464 Assembling of gear into force transmitting device
• CPC Class Codes: Y10T 408/65 Means to drive tool

Abstract

A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Claims

1. A support cage for supporting and positioning power transfer tiltable balls in a rolling traction transmission, the cage comprising:

first and second support discs, each disc comprising a sheet having a plurality of two-sided slots;

a first plurality of spacers extending between the first and second discs, each spacer having front and back sides and first and second ends;

wherein the first and second ends each has a mounting surface, each mounting surface having a curved surface; and

wherein the first plurality of spacers are positioned angularly about the first and second discs, between the slots in the support discs, such that the curved surfaces align with the sides of the slots.

2. The cage of claim 1, wherein at least one of the support discs comprises a generally circular sheet.

3. The cage of claim 1, wherein at least one of the support discs comprises a central bore and the slots extend radially from the central bore to the perimeter of the disc.

4. The cage of claim 1, wherein at least one of the spacers comprises a generally flat rectangular sheet having a through hole positioned at or near the center of the rectangular sheet.

5. The cage of claim 1, wherein there are two spacers for each ball.

6. The cage of claim 1, further comprising:

third and fourth support discs, each disc comprising a sheet having a plurality of two-sided slots;

a second plurality of spacers extending between the third and fourth support discs, each spacer having front and back sides and first and second ends;

wherein the first and second ends each has a mounting surface, each mounting surface having a curved surface; and

wherein the second plurality of spacers are positioned angularly about the third and fourth support discs, between the slots in the third and fourth support discs, such that the curved surfaces align with the sides of the slots.

7. The cage of claim 6, further comprising a stator bridge coupled to the first and third support discs.

8. The cage of claim 7, wherein the stator bridge comprises a cylindrical body having a central bore.

9. A method of manufacturing a support cage for supporting and positioning power transfer tiltable balls in a rolling traction transmission, the method comprising:

providing first and second support bodies, each body comprising a sheet having a plurality of slots; and

placing a first plurality of spacers between the first and second support bodies, each spacer having curved first and second ends; and

positioning the first plurality of spacers angularly about the first and second discs, between the slots, such that the curved first and second ends align with the sides of corresponding slots.

10. The method of claim 9, wherein at least one of the support bodies comprises a generally circular sheet.

11. The method of claim 9, wherein at least one of the support bodies comprises a central bore and the slots extend radially from the central bore to the perimeter of the body.

12. The method of claim 9, wherein at least one of the spacers comprises a generally flat rectangular sheet having a through hole positioned at or near the center of the rectangular sheet.

13. The method of claim 9, wherein there are two spacers for each ball.

14. The method of claim 9, further comprising:

providing third and fourth support bodies, each body comprising a sheet having a plurality of slots; and

placing a second plurality of spacers between the third and fourth support bodies, each spacer having first and second curved ends;

positioning the second plurality of spacers angularly about the third and fourth support bodies, between the slots in the third and fourth support bodies, such that the curved ends align with the sides of the slots.

15. The method of claim 14, further comprising a stator bridge coupled to the first and third support bodies.

16. The method of claim 15, wherein the stator bridge comprises a cylindrical body having a central bore.

17. A support cage for supporting and positioning power transfer tiltable balls in a rolling traction transmission, the cage comprising:

a first, second, third, and fourth supports, each support having a plurality of slots;

a first and second pluralities of spacers, each spacer having first and second curved ends;

a stator bridge coupled to the first and third supports, the stator bridge comprising a cylindrical body having a central bore;

wherein the first plurality of spacers is positioned between and angularly about the first and second supports; and

wherein the second plurality of spacers is positioned between and angularly about the third and fourth supports.

18. The cage of claim 17, wherein at least one of the supports comprises a generally circular sheet.

19. The cage of claim 18, wherein at least one of the supports comprises a central bore and the slots extend radially from the central bore to the perimeter of the support.

20. The cage of claim 17, wherein at least one of the spacers comprises a generally flat rectangular sheet having a through hole positioned at or near the center of the rectangular sheet.