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US4651040A Expired / Lapsed US ⏱️ 0.0 years remaining

Induction motor

Assignee: Robert Bosch GmbH
•
Filing: 1984-12-08
•
Granted: 1987-03-17
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Expires: 2004-12-08
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Abstract

Abstract An induction motor is suggested with a permanent magnet rotor and a stator which is excited electromagnetically by an alternating field, whereby an electrically conductive rotor outer part (17) is mounted between a freely rotatable permanent magnetic rotor inner part (16) and the stator poles (11,12) in the form of a hollow cylinder or a short circuit cage. The rotor outer part (17) rotates in form of a cage runner asynchronous and drives the connected load, after the start of the permanent magnetic inner part (16) which runs synchronous in the continuous operation. A rotating direction arresting device (36,37) assures a defined rotating direction of a drive shaft (27).

Inventors

  • 👤 Bruno Gerstner
  • 👤 Rudiger Pfeiffer
  • 👤 Berthold Seng

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 22:26
CPC Classifications
D; D06; D06F; D06F39/00; D06F39/08; D06F39/083; D06F39/085; H; H02; H02K; H02K16/00; H02K16/02; H02K7/00; H02K7/10; H02K7/118; H02K7/1185; D06F2103/00; D06F2103/44; D06F2103/48; H02K17/00; H02K17/02; H02K17/04; H02K21/00; H02K21/12; H02K21/14; H02K21/16

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 205 words
An induction motor preferably for pump drives, comprising: a rotor having a rotor inner part and a rotor outer part; at least one permanent magnet supported by said rotor inner part; a stator surrounding said rotor inner part circumferentially such that an air space is formed therebetween, said rotor outer part being arranged between said stator and said rotor inner part in said air space, said air space having a width between said rotor outer part and said stator which varies around said rotor outer part to define an air space shape, said stator being excitable by an alternating electromagnetic field to provide a stator magnetic field direction for generating a starting torque, said rotor inner part being movable into a rest position because of said air space shape to provide a rotor magnetic field direction which is different from said stator magnetic field direction, said rotor inner part being rotatable synchronously with respect to said stator field direction, said rotor outer part being rotatable with respect to said rotor inner part and being rotatable asynchronously with respect to said stator field direction; and a drive shaft connected to said rotor outer part, said rotor outer part being formed as an electrically conductive hollow cylinder.
Claim 2
Dependent Claim 205 words
An induction motor preferably for pump drives, comprising: a rotor having a rotor inner part and a rotor outer part; at least one permanent magnet supported by said rotor inner part; a stator surrounding said rotor inner part circumferentially such that an air space is formed therebetween, said rotor outer part being arranged between said stator and said rotor inner part in said air space, said air space having a width between said rotor outer part and said stator which varies around said rotor outer part to define an air space shape, said stator being excitable by an alternating electromagnetic field to provide a stator magnetic field direction for generating a starting torque, said rotor inner part being movable into a rest position because of said air space shape to provide a rotor magnetic field direction which is different from said stator magnetic field direction, said rotor inner part being rotatable synchronously with respect to said stator field direction, said rotor outer part being rotatable with respect to said rotor inner part and being rotatable asynchronously with respect to said stator field direction; and a drive shaft connected to said rotor outer part, said rotor outer part being formed as an electrically conductive hollow cylinder.
Claim 3
Dependent Claim 22 words
Induction motor in accordance with claim 1, characterized in that the rotor outer part (17) is composed of a copper hollow cylinder.
Claim 4
Dependent Claim 33 words
Induction motor in accordance with claim 2, characterized in that the rotor outer part (17) is cup shaped and is mechanically connected to the drive shaft in the area of the cup bottom.
Claim 5
Dependent Claim 58 words
Induction motor in accordance with claim 2, characterized in that the drive shaft (27) has a thinner shaft portion and a thicker shaft portion, said rotor inner part (16) being freely rotatable on said thinner shaft portion (28) within said rotor outer part (17), said rotor outer part having a side connected to said thicker shaft portion (29).
Claim 6
Dependent Claim 24 words
Induction motor in accordance with claim 4, characterized in that the rotor outer part (17) is fixedly mounted on the thicker shaft segment (29).
Claim 7
Dependent Claim 21 words
Induction motor in accordance with claim 2, characterized in that a vent (33) is provided on the inner rotor part (16).
Claim 8
Dependent Claim 26 words
Induction motor in accordance with claim 2, characterized in that the permanent magnetic rotor inner part (16) is designed with two poles and is diametrically magnetized.
Claim 9
Dependent Claim 23 words
Induction motor in accordance with claim 2, characterized in that the rotor inner part (16) is assembled from two permanent magnet half shells.
Claim 10
Dependent Claim 26 words
Induction motor in accordance with claim 1, characterized in that the rotor inner part (16) is designed as a unitary piece made from permanent magnet material.
Claim 11
Dependent Claim 37 words
Induction motor in accordance with claim 2; further comprising: a hub (18) inserted axially into said rotor inner part (16) and composed of plastic and mounted on said drive shaft (27, 28) with a slight bearing clearance.
Claim 12
Dependent Claim 12 words
Induction motor as defined in claim 10, wherein said plastic is polytetrafluorethylene.
Claim 13
Dependent Claim 65 words
Induction motor in accordance with claim 2, characterized in that said rotor inner part is rotatable in at least one direction; further comprising: means for blocking said rotor inner part from rotating in said one direction, said blocking means being mounted between said rotor inner part (16) and said rotor outer part (17), to thereby define a predetermined rotating direction of the drive shaft (27).
Claim 14
Dependent Claim 37 words
Induction motor in accordance with claim 12, characterized in that said blocking means includes at least one ratchet pawl (53) pivotably retained on said rotor outer part (17), and a gear (54) on said rotor inner part.
Claim 15
Dependent Claim 14 words
Induction motor in accordance with claim 7, wherein said stator has an asymmetric construction.
Claim 16
Dependent Claim 57 words
Induction motor in accordance with claim 7, wherein said inner part is rotatable in at least one direction; further comprising: means for blocking said inner part from rotating in said one direction; and means for supporting said motor, said supporting means being stationary, said blocking means being mounted between said rotor outer part and said supporting means.
Claim 17
Dependent Claim 47 words
Induction motor in accordance with claim 15; further comprising: a plate mounting said motor, said rotor outer part being cupped shaped and having a bottom area, said blocking means including at least one ratchet pawl pivotably mounted on said plate, and a gear in said bottom area.
Claim 18
Dependent Claim 57 words
Induction motor in accordance with claim 2, wherein said inner part is rotatable in at least one direction; further comprising: means for blocking said inner part from rotating in said one direction; and means for mounting said motor, said mounting means being stationary, said blocking means being mounted between said rotor inner part and said mounting means.
Claim 19
Dependent Claim 38 words
Induction motor in accordance with claim 17; further comprising: a support plate supporting said motor, said blocking means including at least one ratchet pawl pivotably mounted on said support plate, and a gear on said rotor inner part.

References Cited (Backward Citations)

US2159769A Cited
US2492678A Cited
US2974242A Cited
DE1199390B Cited
US3866071A Cited
US4045698A Cited
GB1413782A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-03-16 1990-09-15 1991-03-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-03-16 1994-09-15 1995-03-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-03-16 1998-09-15 1999-03-17 $7700.00 Window Closed / Lapsed

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