Synchronous motor

• US 4,410,818 A
• Filed: 09/17/1982
• Issued: 10/18/1983
• Est. Priority Date: 12/26/1981
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Higashifuji Seisakusho
• Original Assignee: Mitsubishi Mallory Metallurgical Company Limited
• Inventors: Omata, Hiroshi, Katumata, Saichi
• Primary Examiner(s): Duggan, Donovan F.
• Application Number:
  US06/419,621
• Time in Patent Office: 396 Days
• Field of Search: 310/41, 310/83, 310/162-165
• US Class Current: 310/41
• CPC Class Codes: H02K 7/1185 with a mechanical one-way direction control, i.e. with means for reversing the direction of rotation of the rotor

Abstract

A synchronous motor includes a reduction gear train operatively connecting a rotor to an output shaft. A retaining member is rotatably mounted on and frictionally engages the first gear member of the reduction gear train for angular movement about the axis thereof, the first gear member being in mesh with a drive gear on the rotor. The retaining member has an abutment lug which is engageable with the engaging portion when the rotor is rotated in its reverse direction whereupon the engaging portion rebounds from the lug to cause the rotor to rotate in its normal direction. The shaft of the first gear member is parallel to the axis of rotation of the rotor and is disposed at a position angularly displaced about the axis of the rotor from a predetermined point of the rotor by an angle of 360°/P x n when said engaging portion is brought into engagement with the abutment lug wherein P is the number of the magnetic poles around said rotor and n is an integer (0, 1, 2, 3 . . . ).

Claims

1. In a synchronous motor comprising a rotor having a plurality of permanent magnetic poles around its periphery and having a drive gear formed integrally with and coaxially with said rotor, said rotor having an engaging portion;

a reduction gear train operatively connecting said rotor to an output shaft, said reduction gear train comprising a plurality of gear members having respective shafts about which they are rotated, said shafts being parallel to the axis of rotation of said rotor and disposed therearound in spaced relation to each other, a first gear member of said reduction gear train being in mesh with said drive gear;

a stator having a plurality of electromagnetic poles disposed around said rotor; and

a retaining member rotatably mounted on said first gear member and frictionally engaging said first gear member for angular movement about the axis thereof, said retaining member having an abutment lug which is engageable with said engaging portion when said rotor is rotated in one direction whereupon said engaging portion rebounds from said lug to cause said rotor to rotate in the opposite direction;

the improvement wherein the shaft of said first gear member is disposed at a position angularly displaced about the axis of said rotor from a predetermined point of said rotor by an angle of 360°

/P×

n when said engaging portion is brought into engagement with said abutment lug wherein P is the number of the magnetic poles around said rotor and n is an integer (0, 1, 2, 3 . . . ).

2. A method of arranging a reduction gear train for a synchronous motor, said synchronous motor comprising a rotor having a plurality of permanent magnetic poles around its periphery and having a drive gear formed integrally with and coaxially with said rotor, said rotor having an engaging portion;

said reduction gear train operatively connecting said rotor to an output shaft, said reduction gear train comprising a plurality of gear members having respective shafts about which they are rotated, said shafts being parallel to the axis of rotation of said rotor and disposed therearound in spaced relation to each other, a first gear member of said reduction gear train being in mesh with said drive gear;

said synchronous motor also comprising a stator having a plurality of electromagnetic poles disposed around said rotor; and

a retaining member rotatably mounted on said first gear member and frictionally engaging said first gear member for angular movement about the axis thereof, said retaining member having an abutment lug which is engageable with said engaging portion when said rotor is rotated in one direction whereupon said engaging portion rebounds from said lug to cause said rotor to rotate in the opposite direction;

said method comprising the step of locating the shaft of said first gear member at a position angularly displaced about the axis of said rotor from a predetermined point of said rotor by an angle of 360°

/P×

n when said engaging portion is brought into engagement with said abutment lug wherein P is the number of the magnetic poles around said rotor and n is an integer (1, 2, 3 . . . ).