Multiple speed automatic transmission

• US 20080182704A1
• Filed: 01/25/2007
• Published: 07/31/2008
• Est. Priority Date: 01/25/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Goleski, Gregory D., Hoffman, Donald E., Thomas, Steve G.
• Granted Patent: US 7,766,785 B2
• Time in Patent Office: Days
• US Class Current: 475/269
• CPC Class Codes: F16H 2200/006 the gear ratios comprising eight forward speeds
• CPC Class Codes: F16H 2200/0086 the gear ratios comprising two reverse speeds
• CPC Class Codes: F16H 2200/2007 with two sets of orbital gears
• CPC Class Codes: F16H 2200/2023 using a Ravigneaux set with 4 connections
• CPC Class Codes: F16H 2200/2046 with six engaging means
• CPC Class Codes: F16H 3/663 with conveying rotary motion between axially spaced orbital gears, e.g. RAVIGNEAUX

Abstract

A multiple-speed automatic transmission includes an input, output, a first gear unit drivable connected to the input and including a component rotating at the speed of the input and a first gear unit output, the first gear unit producing a gear ratio of a speed of the input and a speed of a first gear unit output, the gear ratio being greater than unity, and a Ravigneaux gear unit for producing multiple ratios of the speed of the input and a speed of the output, the Ravigneaux gear unit being driveably connected to first, second, third, fourth, fifth and sixth rotating members and the output. A first clutch connects the first gear unit output and the first rotating member; a second clutch connects the first gear unit output and the second rotating member; a third clutch connects the third rotating member and one of the input and the rotating component, a fourth clutch connects the fourth rotating member and one of the input and the component; a first brake holds the fifth rotating member against rotation; and a second brake holds the sixth rotating member against rotation.

Claims

1. A multiple-speed automatic transmission comprising:

an input;

an output;

a first gear unit drivable connected to the input and including a component rotating at the speed of the input and a first gear unit output, the first gear unit producing a gear ratio of a speed of the input and a speed of a first gear unit output, the gear ratio being greater than unity;

a Ravigneaux gear unit for producing multiple ratios of the speed of the input and a speed of the output, the Ravigneaux gear unit being driveably connected to first, second, third, fourth, fifth, and sixth rotating members and the output;

a second clutch being operable to connect the first gear unit output and the second rotating member;

a third clutch being operable to connect the third rotating member and one of the input and the rotating component;

a fourth clutch being operable to connect the fourth rotating member and one of the input and the component;

a first brake being operable to hold the fifth rotating member against rotation; and

a second brake being operable to hold the sixth rotating member against rotation.

2. The transmission of claim 1 wherein:

the Ravigneaux gearset includes a first sun gear secured to the first rotating member;

a second sun gear secured to the second rotating member, the fourth rotating member and the fifth rotating member;

a first ring gear secured to the output;

a first carrier secured to the third and the sixth rotating members;

first planet pinions rotatably supported on the first carrier and meshing with the first sun gear;

second planet pinions rotatably supported on the first carrier and meshing with the second sun gear, first planet pinions and first ring gear; and

the first gear unit includes a third sun gear secured to the input, the third clutch and the fourth clutch;

a second ring gear secured to the first and second clutches;

a second carrier grounded against rotation and secured to the first brake;

third planet pinions supported on the second carrier and meshing with the third sun gear; and

fourth planet pinions supported on the second carrier and meshing with the third planet pinions, and the second ring gear.

3. The transmission of claim 1 wherein:

the Ravigneaux gearset includes a first sun gear secured to the first rotating member;

a second sun gear secured to the second rotating member, the fourth rotating member and the fifth rotating member;

a first ring gear secured to the output;

a first carrier secured to the third and the sixth rotating members;

first planet pinions rotatably supported on the first carrier and meshing with the first sun gear;

second planet pinions rotatably supported on the first carrier and meshing with the second sun gear, first- planet pinions and first ring gear; and

the first gear unit includes a third sun gear secured to the input and the third clutch;

a fourth sun secured to the fourth clutch;

a second ring gear grounded against rotation;

a second carrier secured to the first and second clutches; and

third planet pinions supported on the second carrier and meshing with the third sun gear, the fourth sun gear and the second ring gear.

4. The transmission of claim 1 wherein operation in a forward gear or a reverse gear is produced by concurrent engagement of two of the group consisting of the first clutch, the second clutch, the third clutch, the fourth clutch, the first brake, and the second brake.

5. The transmission of claim 1 wherein engagement of the first clutch and the second brake and disengagement of the second clutch, the third clutch, the fourth clutch, and the first brake produce a first forward gear having a first gear ratio.

6. The transmission of claim 1 wherein engagement of the first clutch and the first brake and disengagement of the second clutch, the third clutch, the fourth clutch, and the second brake produce a second forward gear having a second speed ratio that is less than the first speed ratio.

7. The transmission of claim 1 wherein engagement of the first clutch and the second clutch and disengagement of the third clutch, the fourth clutch, the first brake, and the second brake produce a third forward gear having a third gear ratio that is less than the second gear ratio.

8. The transmission of claim 1 wherein engagement of the first clutch and the fourth clutch and disengagement of the second clutch, the third clutch, the first brake, and the second brake produce a fourth forward gear having a fourth speed ratio that is less than the third gear ratio.

9. The transmission of claim 1 wherein engagement of the first clutch and the third clutch and disengagement of the second clutch, the fourth clutch, the first brake, and the second brake produce a fifth forward gear having a fifth gear ratio that is less than the fourth gear ratio.

10. The transmission of claim 1 wherein engagement of the third clutch and the fourth clutch and disengagement of the first clutch, the second clutch, the first brake, and the second brake produce a sixth forward gear having a sixth gear ratio that is less than the fifth gear ratio.

11. The transmission of claim 1 wherein engagement of the second clutch and the third clutch and disengagement of the first clutch, the fourth clutch, the first brake, and the second brake produce a seventh forward gear having a seventh gear ratio that is less than the sixth gear ratio.

12. The transmission of claim 1 wherein engagement of the first brake and the third clutch and disengagement of the first clutch, the second clutch, the fourth clutch, and the second brake produce an eight forward gear having a eighth gear ratio that is less than the seventh gear ratio.

13. The transmission of claim 1 wherein engagement of the second clutch and the second brake and disengagement of the first clutch, the third clutch, the fourth clutch, and the first brake produce a low speed reverse gear having a first reverse gear ratio.

14. The transmission of claim 1 wherein engagement of the fourth clutch and the second brake and disengagement of the first clutch, the second clutch, the third clutch, and the first brake produce a relatively higher reverse gear having a gear ratio that is less than the first reverse gear ratio.

15. A multiple-speed automatic transmission comprising:

an input;

an output;

a Ravigneaux gearset including a first sun gear;

a second sun gear;

a first ring gear secured to the output;

a first carrier;

first planet pinions rotatably supported on the first carrier and meshing with the first sun gear;

second planet pinions rotatably supported on the first carrier and meshing with the second sun gear, the first planet pinions and the first ring gear;

a first gear unit including a third sun gear;

a second ring gear;

a second carrier grounded against rotation;

third planet pinions supported on the second carrier and meshing with the third sun gear; and

fourth planet pinions supported on the second carrier and meshing with the third planet pinions and the second ring gear;

a first clutch being operable to connect the second ring gear and the first sun gear;

a second clutch being operable to connect the second ring gear and the second sun gear;

a third clutch being operable to connect the first carrier and the input;

a fourth clutch being operable to connect the second sun gear and the input;

a first brake being operable to hold the second sun gear against rotation; and

a second brake being operable to hold the first carrier against rotation.

16. The transmission of claim 15, wherein:

a low-reverse gear having a first reverse gear ratio is produced when the second clutch and second brake are engaged.

17. The transmission of claim 15, wherein:

a low-reverse gear having a second reverse gear ratio less than the first reverse gear ratio is produced when the fourth clutch and second brake are engaged.

18. A multiple-speed automatic transmission comprising:

an input;

an output;

the Ravigneaux gearset includes a first sun gear;

a second sun gear;

a first ring gear secured to the output;

a first carrier;

first planet pinions rotatably supported on the first carrier and meshing with the first sun gear;

second planet pinions rotatably supported on the first carrier and meshing with the second sun gear, first planet pinions and first ring gear;

the first gear unit includes a third sun gear secured to the input;

a fourth sun;

a second ring gear grounded against rotation;

a second carrier; and

third planet pinions supported on the second carrier and meshing with the third sun gear, the fourth sun gear and the second ring gear;

a first clutch being operable to connect the second carrier and the first sun gear;

a second clutch being operable to connect the second carrier and the second sun gear;

a third clutch being operable to connect the input and the first carrier;

a fourth clutch being operable to connect the fourth sun gear and the second sun gear;

a first brake being operable to hold the second sun gear against rotation; and

a second brake being operable to hold the first carrier against rotation.

19. The transmission of claim 18, wherein:

a low-reverse gear having a first reverse gear ratio is produced when the second clutch and second brake are engaged.

20. The transmission of claim 19, wherein:

a low-reverse gear having a second reverse gear ratio less than the first reverse gear ratio is produced when the fourth clutch and second brake are engaged.