Wet type friction clutch and electromagnetic clutch

• US 6,719,110 B2
• Filed: 07/02/2002
• Issued: 04/13/2004
• Est. Priority Date: 07/05/2001
• Status: Active Grant

• Current Assignee: Tochigi Fuji Sangyo Kabushiki Kaisha (Melrose Industries Plc)
• Original Assignee: Tochigi Fuji Sangyo Kabushiki Kaisha (Melrose Industries Plc)
• Inventors: Ishizuka, Makoto, Kitsunezuka, Yoshiaki, Karasawa, Kenji, Koshigaya, Yasushi, Iizuka, Kouji, Nakabayashi, Yoshiyuki, Sayama, Masayuki, Ishikawa, Yasuhiko
• Primary Examiner(s): Lorence, Richard M.
• Application Number:
  US10/189,220
• Publication Number:
  US 20030015385A1
• Time in Patent Office: 651 Days
• Field of Search: 192/35, 192/70.12, 192/84.7, 192/84.91, 192/84.96, 192/113.34
• US Class Current: 192/35
• CPC Class Codes: F16D 13/69 Arrangements for spreading lamellae in the released state
• CPC Class Codes: F16D 2027/008 Details relating to the magnetic circuit, or to the shape of the clutch parts to achieve a certain magnetic path
• CPC Class Codes: F16D 25/123 in view of cooling and lubrication
• CPC Class Codes: F16D 27/004 with permanent magnets combined with electromagnets
• CPC Class Codes: F16D 27/115 with more than two discs, e.g. multiple lamellae
• CPC Class Codes: F16H 2048/346 using a linear motor
• CPC Class Codes: F16H 48/22 using friction clutches or brakes

Abstract

A wet type friction clutch and an electromagnetic clutch is disclosed wherein a pilot clutch 61 is disposed in a magnetic flux path 95 of an electromagnet 57 and is kept between an armature 71 and the electromagnet 57. Upon excitation of the electromagnet 57, the armature 57 is retracted to allow the pilot clutch 61 to be coupled. The pilot clutch 61 includes a plurality of clutch plates 87, 89 which are interleaved with respect to one another for sliding movements. Adjacent clutch plates 87, 87A, 87B, 89, 89A, 89B, 89C, 89D, 89E, 89F are formed with oil guide passageways 86, 96, 98, 106, 108, 110, 114 to create a hydrodynamic pressure effect to allow the clutch plates to be separated with a limited drag torque. Further, the clutch plate has magnetic flux path forming portions 89b, 89c, at inner and outer peripheral sides, between which through-bores 112 are formed to allow bridge portions 120 to be intervened between the through-bores, with each of the bridge portions being configured such that opposing walls of the bridge portions of adjacent clutch plates have reduced contact surface areas to eliminate a leakage of a magnetic flux.

Claims

1. A wet type friction clutch operatively disposed between first and second torque transmission components, comprising:

a first plurality of clutch plates disposed for rotation with the first torque transmission component;

a second plurality of clutch plates interleaved with the first plurality of clutch plates and disposed for rotation with the second torque transmission component;

a clutch operator operative to selectively render the first and second plurality of clutch plates to engage or disengage; and

an oil guide passageway formed on at least one of adjacent clutch plates to introduce an oil to sliding areas of the adjacent clutch plates and extending in a given length along circumferential peripheries of the adjacent clutch plates to communicate with an oil chamber to allow the oil to be introduced into the sliding areas of the adjacent clutch plates,

wherein the oil guide passageway has an edge portion with a thickness smaller than that of a body portion of the clutch plate to define a space between adjacent clutch plates.

2. A wet type friction clutch according to claim 1, wherein the oil guide passageway is formed in a radial direction of the clutch plate and communicates with the oil chamber.

3. A wet type friction clutch according to claim 1, wherein the oil guide passageway is formed to communicate between an outer diameter side and an inner diameter side of the clutch plate.

4. A wet type friction clutch according to claim 1, wherein the oil guide passageway has an edge portion contiguous with an outer surface of the clutch plate via an inclined surface.

5. A wet type friction clutch according to claim 1, wherein the oil guide passageway has opposite ends formed with respective edge portions each configured in a circular arc shape.

6. A wet type friction clutch according to claim 1, wherein the clutch operator comprises an electromagnetic clutch which includes an electromagnetic coil having a magnetic flux path in which the first and second plurality of clutch plates are operatively disposed, and an armature attracted by a magnetic flux of the electromagnet, the first and second plurality of clutch plates having gap portions which form a part of the magnetic flux path, and the oil guide passage being formed between the gap portions.

7. A wet type friction clutch operatively disposed between first and second torque transmission components, comprising:

a first plurality of clutch plates disposed for rotation with the first torque transmission component;

a second plurality of clutch plates interleaved with the first plurality of clutch plates and disposed for rotation with the second torque transmission component;

a clutch operator operative to selectively render the first and second plurality of clutch plates to engage or disengage;

a first oil guide passageway formed on at least one of adjacent clutch plates to introduce an oil into sliding areas of the adjacent clutch plates; and

a second oil guide passageway formed on the other one of the adjacent clutch plates;

wherein the first oil guide passageway is formed to have a volume different from that of the second oil guide passageway to allow the oil to be introduced into the sliding areas of the adjacent clutch plates from the first and second oil guide passageways.

8. A wet type friction clutch according to claim 7, Therein the first oil guide passageway has a larger width in a radial direction of the clutch plate than that of the second oil guide passageway.

9. A wet type friction clutch according to claim the first oil guide passageway has an end portion formed with an extension which radially extends outward and terminates in an area outside an area in which the second oil guide passageway is formed.

10. A wet type friction clutch according to claim 7, wherein the first oil guide passageway has both ends formed with expanded portions, respectively, each of which radially expands in a larger width than that of the second oil guide passageway.

11. A wet type friction clutch according to claim 7, wherein at least one of the first and second oil guide passageways has both lengthwise ends each formed with an edge which is smaller in thickness than a body portion of the clutch plate.

12. A wet type friction clutch according to claim 7, the first and second oil guide passageways are communicable with one another in an axial direction.

13. A wet type friction clutch according to claim 7, wherein the clutch operator comprises an electromagnetic clutch which includes an electromagnetic coil having a magnetic flux path, in which the first and second plurality of clutch plates are operatively disposed, and an armature operative to be retracted by a magnetic flux of the electromagnetic coil, wherein the first and second oil guide passageways form gap portions, respectively, to define magnetic permeability reduction means for establishing the magnetic flux path.

14. A clutch plate for an electromagnetic clutch having a group of clutch plates including first clutch plates disposed for rotation with a drive shaft and second clutch plates interleaved with the first clutch plates and disposed for rotation with a driven shaft, an electromagnet disposed at one side of the group of clutch plates, and an armature disposed at the other side of the group of clutch plates to be retracted by an electromagnetic force generated by the electromagnet for thereby causing the group of clutch plates to be brought into pressured contact such that the clutch plates are coupled, wherein the clutch plate has a plurality of through-bores, formed along a circumferential periphery of the clutch plate in alignment with a magnetic flux path forming portion which establishes a magnetic flux path generated by the electromagnet, between which a bridge portion is intervened for interconnecting an inner circumferential periphery and an outer circumferential periphery of the clutch plate, the clutch plate comprising:

a body formed with oil guide passageways, composed of the through-bores, and the bridge portions, each of which includes opposing walls facing opposed clutch plates, respectively, and an inner wall facing each of the through-bores, wherein each of the bridge portions is formed such that, while ensuring a given cross sectional area, a circumferentially peripheral length of the opposing wall is shorter than that of each bridge portion.

15. A clutch plate for an electromagnetic clutch having a group of clutch plates including first clutch plates disposed for rotation with a drive shaft and second clutch plates interleaved with the first clutch plates and disposed for rotation with a driven shaft, an electromagnetic coil disposed at one side of the group of clutch plates, and an armature disposed at the other side of the group of clutch plates to be retracted by an electromagnetic force generated by the electromagnetic coil for thereby causing the group of clutch plates to be brought into pressured contact such that the clutch plates are coupled, wherein the clutch plate has a plurality of through-bores, formed along a circumferential periphery of the clutch plate in alignment with a magnetic flux path forming portion which establishes a magnetic flux path generated by the electromagnetic coil, between which a bridge portion is intervened for interconnecting an inner circumferential periphery and an outer circumferential periphery of the clutch plate, the clutch plate comprising:

a body formed with oil guide passageways, composed of the through-bores, and the bridge portions each of which includes opposing walls facing opposed clutch plates, respectively, and an inner wall facing each of the through-bores, wherein each of the bridge portions is formed such that, while ensuring a given cross sectional area, each bridge portion is smaller in thickness than the magnetic flux path forming portion.