Ball type CVT with powersplit paths

• US 9,353,842 B2
• Filed: 09/06/2013
• Issued: 05/31/2016
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: DANA Limited (Caterpillar Incorporated)
• Original Assignee: DANA Limited (Caterpillar Incorporated)
• Inventors: Versteyhe, Mark R. J., Byltiauw, Matthias W. J.
• Primary Examiner(s): KNIGHT, DEREK DOUGLAS
• Application Number:
  US14/426,139
• Publication Number:
  US 20150204430A1
• Time in Patent Office: 998 Days
• US Class Current: 1/1
• CPC Class Codes: F16H 15/28 with external friction surface
• 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 2037/0873 with switching, e.g. to change ranges
• CPC Class Codes: F16H 2037/0893 characterised in the ratio of the continuously variable transmission is different from zero when the output shaft speed is zero
• CPC Class Codes: F16H 2037/103 Power split variators with each end of the CVT connected or connectable to a Ravigneaux set
• CPC Class Codes: F16H 2037/107 with switching means to provide three variator modes or ranges
• CPC Class Codes: F16H 37/022 the toothed gearing having orbital motion
• CPC Class Codes: F16H 37/082 and additional planetary reduction gears
• CPC Class Codes: F16H 37/086 CVT using two coaxial friction members cooperating with at least one intermediate friction member
• CPC Class Codes: F16H 37/10 at both ends of intermediate shafts F16H37/0806 takes precedence

Abstract

A variable transmission comprises an input shaft; three planetary gear sets; a Ravigneaux gear set; a variator comprising, a first ring assembly, a second ring assembly, a carrier assembly; various arrangements of brakes and clutches; and the output shaft. The variable transmissions comprise a continuously variable mode, an infinitely variable mode, or a combination thereof and can provide an input-coupled powersplit solution function. At least one configuration of the variable transmission comprises a direct drive mode.

Claims

1. A variable transmission comprising:

an input shaft;

a first planetary gear set, a second planetary gear set and a third planetary gear set;

a variator comprising a first ring assembly, a second ring assembly;

a first clutch, a second clutch and a third clutch; and

a first brake comprising a first brake member,

wherein said input shaft is drivingly engaged with the first ring assembly of the variator, and mechanically coupleable to a first planetary sun of the first planetary gear set using the second clutch;

wherein said input shaft is also drivingly engaged with the third sun of the third planetary gear set;

wherein the second ring assembly is drivingly engaged with a ring of the third planetary gear set;

wherein a first carrier of the first planetary gear set and a second carrier of the second planetary gear set are coupled together,

wherein a third carrier of the third planetary gear set is mechanically coupleable to the first carrier of the first planetary gear set and the second carrier of the second planetary gear set through the third clutch;

wherein the first brake member is coupled to the ring of the second planetary gear set; and

wherein the first ring of the first planetary gear set is mechanically coupled to the output of the transmission;

wherein the third carrier is mechanically coupled to the second sun of the second planetary gear set;

wherein the first sun of the first planetary gear set might be coupled to the first ring of the first planetary gear set with the first clutch.

2. The variable transmission of claim 1, comprising two continuously variable modes and an infinitely variable mode and a direct drive mode.

3. The variable transmission of claim 2, wherein the continuously variable modes of claim 2 comprise a low speed (CVM1) and a high speed (CVM2).

4. The variable transmission of claim 2, wherein either or both of the continuously variable modes and infinitely variable modes are enabled by blocking rotation of a variator carrier of the variator.

5. The variable transmission of claim 2, wherein engaging the first clutch and the first brake at the second planetary gear set reduces speed of the second ring assembly and allows the first planetary gear set to turn at a 1:

1 ratio, thereby engaging a first of the two continuously variable modes (CVM1).

6. The variable transmission of claim 2, wherein engaging the first clutch and the third clutch drives the output speed of the variator second ring assembly through the carrier of the first planetary gear set causing the first planetary gear set to turn at a 1:

1 output ratio to the differential, thereby engaging a second continuously variable mode (CVM2) with powersplitting.

7. The variable transmission of claim 2, wherein engaging the first clutch and the second clutch bypasses the variator and allows output of the first planetary gear set to turn at a 1:

1 ratio with the input shaft, directly engaging a vehicle output, thus engaging a direct drive mode.

8. The variable transmission of claim 2, wherein engaging the second clutch and the first brake engage a infinitely variable mode that allows positive speeds, negative speeds and powered neutral (IVP).

9. The variable transmission of claim 1, wherein power from the input shaft passes through the variator and simultaneously passes to a vehicle output.

10. The variable transmission of claim 1, wherein engaging the second clutch and the first brake results in an infinitely variable mode.

11. The variable transmission of claim 10, wherein reverse and low positive speeds can be obtained when the input shaft is directly engaged to the first sun of the first planetary gear set.

12. The variable transmission of claim 1, comprising a traction fluid.

13. The variable transmission of claim 1, disposed between an engine and a vehicle output, thereby forming a vehicle driveline.

14. A variable transmission comprising:

an input shaft;

a variator comprising a first ring assembly, a second ring assembly;

a first planetary gear set, a second planetary gear set and a third planetary gear set;

a Ravigneaux gear set;

a first clutch; and

a first brake and a second brake,

wherein the input shaft is drivingly engaged with a first sun of the first planetary gear set having the second brake coupled to the ring of this first planetary gear set;

wherein the input shaft is drivingly engaged with a second carrier of the second planetary gear set;

wherein a second sun of the second planetary gear set is coupled to the first ring assembly of the variator,

wherein the second ring assembly is drivingly engaged with a third sun of the third planetary gear set which is fixed to ground by its ring,

wherein a third carrier of the third planetary gear set is drivingly engaged to a second ring of the second planetary gear set;

wherein a second ring of the second planetary is drivingly engaged with the first sun of the Ravigneaux gear set which is mechanically coupled to the first brake by its second sun; and

wherein a ring of the Ravigneaux gear set is engaged with a vehicle output; and

wherein a first clutch engages the first sun of the Ravigneaux gear set to a carrier of the Ravigneaux gear set.

15. The variable transmission of claim 14, wherein the first brake holds the second sun of the Ravigneaux gear set.

16. The variable transmission of claim 14, wherein the second brake holds the ring gear of the first planetary gear set.

17. The variable transmission of claim 14, wherein the carrier of the Ravigneaux gear set is linked to a first carrier of the first planetary gear set.

18. The variable transmission of claim 14, comprising a first continuously variable mode, a second continuously variable mode, and an infinitely variable mode.

19. The variable transmission of claim 18, wherein the first sun of the Ravigneaux gear set is engaged in all of the first continuously variable mode, the second continuously variable mode, and the infinitely variable mode.

20. The variable transmission of claim 14, wherein the second brake is engaged to hold the first ring of the first planetary gear set, thereby engaging the infinitely variable mode.

21. The variable transmission of claim 20, wherein the speed of second ring of the Ravigneaux is reduced.

22. The variable transmission of claim 14, wherein when the first brake is engaged the second sun is held which results in a first continuously variable mode (CVM1) of operation.

23. The variable transmission of claim 14, wherein when the first clutch is engaged, the Ravigneaux gear set is engaged which results in a second continuously variable mode (CVM2) of operation.

24. The variable transmission of claim 23, wherein in the second continuously variable mode (CVM2) of operation the entire Ravigneaux gear set turns at the same speed, and achieves an efficient 1:

1 ratio.

25. The variable transmission of claim 14, further comprising a second clutch and a third brake, the second clutch operably coupled to the third planetary gear set, the third brake operably coupled to the third planetary gear set.

26. The variable transmission of claim 14, comprising a traction fluid.

27. The variable transmission of claim 14, disposed between an engine and a vehicle output, thereby forming a vehicle driveline.