Electromagnetic clutch with an improved magnetic rotatable member

• US 4,694,945 A
• Filed: 10/16/1984
• Issued: 09/22/1987
• Est. Priority Date: 10/16/1984
• Status: Expired due to Term

• Current Assignee: Takatoshi Koitabashi
• Original Assignee: Sanden Corporation (Hisense Home Appliances Group Co., Ltd.)
• Inventors: Koitabashi, Takatoshi
• Primary Examiner(s): Krizmanich, George H.
• Application Number:
  US06/661,465
• Time in Patent Office: 1,071 Days
• Field of Search: 192/84 C, 192/12 D, 192/17 C, 192/18 B, 192/84 C, 188/161, 310/78
• US Class Current: 192/84.961
• CPC Class Codes: B21D 53/261 pulleys
• CPC Class Codes: B23P 15/14 gear parts, e.g. gear wheels
• 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 27/112 with flat friction surfaces, e.g. discs

Abstract

An electromagnetic clutch includes a first rotatable member of magnetic material having an axial end surface and a hollow portion in which an annular electromagnetic device is disposed in a stationary position. A second rotatable member, such as a drive shaft, is provided within the first rotatable member. A hub is secured on the second rotatable member and a magnetic armature plate is supported on and around the hub. The magnetic armature plate, which faces the axial end surface of the first rotatable member at a predetermined axial air gap, is capable of limited axial movement and is attracted to the first rotatable member when the electromagnetic device is energized to frictionally engage the first rotatable member. In particular, in the electromagnetic clutch of this invention, the first rotatable member includes an outer cylindrical member, an inner cylindrical member and an axial end plate member which has an axial end surface connected therebetween, with the outer diameter of the axial end plate member exceeding the diameter of the outer cylindrical member and the inner diameter being smaller than the diameter of the inner cylindrical member.

Claims

1. An electromagnetic clutch including a first rotatable member of magnetic material rotatably supported on a bearing, an annular electromagnetic device disposed in a stationary position in a hollow portion of said first rotatable member, said annular electromagnetic device including an annular magnetic housing, an annular magnetic coil disposed therein, a second rotatable member, a hub secured on said second rotatable member, a magnetic armature plate supported on and around said hub at a predetermined radial gap, said magnetic armature plate being capable of limited axial movement and facing said first rotatable member at a predetermined axial air gap, said magnetic armature plate further being attracted to said first rotatable member when said annular magnetic coil is energized, the improvement comprising said first rotatable member comprising an outer cylindrical member, an inner cylindrical member and an axial end plate member which has an axial end surface connecting said outer and inner cylindrical members, wherein the outer diameter of said axial end plate member is larger than the diameter of any part of the outer cylindrical member and the inner diameter of said axial end plate member is smaller than the diameter of any part of the inner cylindrical member.

2. The electromagnetic clutch of claim 1 wherein said first rotatable member is a single piece of pressed and drawn metal and an axial end portion of both of said cylindrical members is connected to said axial end plate member through a drawn flange portion.