Dual mass flywheel

Patent metadata

Field	Value
Publication number	US-9964177-B2
Application number	US-201214353160-A
Country	US
Kind code	B2
Filing date	Oct 22, 2012
Priority date	Oct 21, 2011
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

The dual mass flywheel comprises a spring assembly ( 4; 104; 112; 128; 129 ), if necessary, with two stages of which one can include a spiral spring. Furthermore, the dual mass flywheel comprises a friction damping system ( 111 ) that applies torque independently of the rotational speed of the flywheel.

First claim

The invention claimed is:

1. A dual mass flywheel comprising:
a primary mass,
a secondary mass angularly movable with respect to said primary mass, and
a spring assembly to connect said primary mass to said secondary mass, the spring assembly comprising:
a first spring stage comprising at least one spiral spring,
a second spring stage having a torsional stiffness greater than that of the said first spring stage, and
a structure configured to connect said first spring stage in series with said second spring stage,
wherein said at least one spiral spring comprises a first end portion rigidly connected to said primary mass or to said secondary mass and a second end portion connected to a body of said structure, said first spring stage as a whole being placed side by side, in the axial direction, to said second spring stage.

2. A flywheel according to claim 1 , wherein said body is radially surrounded by said at least one spiral spring and is radially supported by and surrounds a tubular portion of one of said primary and secondary masses.

3. A flywheel according to claim 1 , wherein said second spring stage comprises a plurality of cylindrical springs.

4. A flywheel according to claim 1 , further comprising a friction device arranged in parallel to said structure and said second spring stage and comprising an axial loading spring acting against at least one friction element positioned to dampen the torsional oscillations within said flywheel so as to generate a friction effect substantially independent of the rotational speed of said flywheel.

5. A flywheel according to claim 4 , wherein said friction device is a dry friction device.

6. A flywheel according to claim 4 , wherein said friction device applies a variable damping action in a manner dependent on the relative angular position between said structure and said primary mass or secondary mass.

7. A flywheel according to claim 6 , wherein said friction device comprises an axial cam and a cam follower.

8. A flywheel according to claim 6 , wherein said friction device is configured to apply a constant friction torque and a variable friction torque summed to said constant friction torque, wherein the variable friction torque is in the range between 0 and 150 Nm.

9. A flywheel according to claim 4 , wherein said friction device applies a constant friction torque in the range between 20 Nm and 70% of the maximum torque of the engine to which it is associated.

10. A flywheel according to claim 4 , wherein one of said first and second spring stages comprises a first and a second element connected to each other and defining an annular compartment radially delimited by a cylindrical wall, said annular compartment housing said friction device and said first and second elements being connected to said primary mass or secondary mass.

11. A flywheel according to claim 10 , wherein at least one of said first and second spring stages comprises a plurality of cylindrical springs and in that said first and second elements are configured to be loaded in a circumferential direction by the action of said cylindrical springs.

12. A flywheel according to claim 10 , wherein said disc is axially interposed between said first and second elements, and said body is connected to said disc in a manner rigid in rotation and free to slide axially.

13. A flywheel according to claim 1 , wherein said structure comprises a disc to load one of said first and second spring stages, wherein said disc is connected to said body in a manner rigid in rotation and free to move axially.

14. A flywheel according to claim 1 , further comprising a cap element rigidly connected between one of said primary and secondary masses and said at least one spiral spring and having a cavity housing an end portion of said at least one spiral spring.

15. An assembly comprising an internal combustion engine and a flywheel according to claim 1 , wherein said primary mass is connected to a crankshaft and said first spring stage is connected between said primary mass and said structure.

Assignees

• Dayco Europe Srl

Inventors

• Cariccia Gianluca
• Giansetto Giacomo
• Montani Andrea
• Guala Andrea

Classifications

• F16F15/13484

  acting on multiple sets of springs · CPC title

• F16F15/1395

  characterised by main friction means acting radially outside the circumferential lines of action of the elastic members · CPC title

• Y10T74/2132

  Structural detail, e.g., fiber, held by magnet, etc. · CPC title

• F16F15/137

  the elastic members consisting of two or more springs of different kinds, {e.g. elastomeric members and wound springs} · CPC title

• F16F15/1333 Primary

  Spiral springs, e.g. lying in one plane, around axis of rotation · CPC title