US 7,443,061 B2Granted

Driving device

AssigneeCanon Kabushiki Kaisha

InventorChikara Aoshima

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Abstract

A driving device which is capable of delivering higher power and can be reduced in size. A hollow-cylindrical magnet (1) is magnetized so as to have circumferentially alternately different poles. First and second coils (2 and 3) are arranged concentric with the magnet (1) on respective axially opposite sides thereof. Tooth-shaped first and second outer magnetic pole parts (8A, 8B, 8C, 8D, 9A, 9B, 9C, and 9D) are arranged in opposed relation to the magnet (1) to extend from respective opposite end faces of the magnet (1), for being magnetized by the first and second coils (2 and 3). A rotary shaft (10) fixed to an inner periphery of the magnet (1) is formed with an inner magnetic pole part (10A) disposed in opposed relation to the first and second outer magnetic pole parts (8A, 8B, 8C, 8D, 9A, 9B, 9C, and 9D), for being magnetized by the first and second coils (2 and 3). The first and second outer magnetic pole parts (8A, 8B, 8C, 8D, 9A, 9B, 9C, and 9D) are each formed into a spiral shape.

Claims6

Dependent claims

A driving device comprising:

a magnet (1) that has a hollow cylindrical shape and is magnetized so as to have alternately different poles in a circumferential direction thereof;
a first coil (2) and a second coil (3) that are arranged concentric with said magnet (1) and disposed on axially opposite sides of said magnet (1), respectively;
first outer magnetic pole parts (8A, 8B, 8C, and 8D) that each have a tooth shape and are arranged in opposed relation to said magnet (1) to extend from a side close to one axial end face of said magnet (1) along an outer peripheral surface of said magnet (1), for being magnetized by said first coil (2);
second outer magnetic pole parts (9A, 9B, 9C, and 9D) that each have a tooth shape and are arranged in opposed relation to said magnet (1) to extend from a side close to another axial end face of said magnet (1) along the outer peripheral surface of said magnet (1), for being magnetized by said second coil (3);
and
a rotary shaft (10) that is fixed to an inner periphery of said magnet (1), and said rotary shaft has an inner magnetic pole part (10A) disposed in opposed relation to at least either of said first outer magnetic pole parts (8A, 8B, 8C, and 8D) and said second outer magnetic pole parts (9A, 9B, 9C, and 9D), for being magnetized by at least one of said first coil (2) and said second coil (3),
wherein said first outer magnetic pole parts (8A, 8B, 8C, and 8D) and said second outer magnetic pole parts (9A, 9B, 9C, and 9D) are each formed into a spiral shape.

4 more elements

A driving device comprising:

a magnet (1) that has a hollow cylindrical shape and is magnetized so as to have alternately different poles in a circumferential direction thereof;
a first coil (2) and a second coil (3) that are arranged concentric with said magnet (1) and disposed on axially opposite sides of said magnet (1), respectively;
first outer magnetic pole parts (58A, 58B, 58C, and 58D) that each have a tooth shape and are arranged in opposed relation to said magnet (1) to extend from a side close to one axial end face of said magnet (1) along an outer peripheral surface of said magnet (1), for being magnetized by said first coil (2);
second outer magnetic pole parts (59A, 59B, 59C, and 59D) that each have a tooth shaped and are arranged in opposed relation to said magnet (1) to extend from a side close to another end face of said magnet (1) along the outer peripheral surface of said magnet (1), for being magnetized by said second coil (3);
and
a rotary shaft (10) that is fixed to an inner periphery of said magnet (1), and said rotary shaft has an inner magnetic pole part (10A) disposed in opposed relation to at least either of said first outer magnetic pole parts (58A, 58B, 58C, and 58D) and said second outer magnetic pole parts (59A, 59B, 59C, and 59D), for being magnetized by at least one of said first coil (2) and said second coil (3),
wherein said magnet (1) is spirally magnetized.

4 more elements

Dependencies are inferred from the claim text.