Method and device for positioning and affixing magnets on a magnetic yoke member of a motor

• US 20050246886A1
• Filed: 05/05/2005
• Published: 11/10/2005
• Est. Priority Date: 05/07/2004
• Status: Active Grant

• Current Assignee: ETEL S.A. (Dr. Johannes Heidenhain GmbH)
• Original Assignee: ETEL S.A. (Dr. Johannes Heidenhain GmbH)
• Inventors: Morel, Jean-Pierre
• Granted Patent: US 7,523,540 B2
• Time in Patent Office: Days
• US Class Current: 29/596
• CPC Class Codes: H02K 15/03 having permanent magnets
• CPC Class Codes: Y10T 29/13 Button-fastener making
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49012 Rotor
• CPC Class Codes: Y10T 29/49076 From comminuted material
• CPC Class Codes: Y10T 29/4981 Utilizing transitory attached element or associated separate material
• CPC Class Codes: Y10T 29/49879 Spaced wall tube or receptacle
• CPC Class Codes: Y10T 29/53083 including means to apply magnetic force directly to position or hold work
• CPC Class Codes: Y10T 29/53143 Motor or generator

Abstract

A method and a device are for positioning and affixing magnets on a magnetic yoke member of an electric motor. The device includes: a nonmagnetic support for receiving the magnets, this support having a shape complementary to that of the magnetic yoke member on which the magnets are to be affixed; a magnetic element for holding the magnets in position on the nonmagnetic support, this element being arranged on the other side of the nonmagnetic support with respect to the magnets, the attraction exerted by this element on the magnets being greater than that exerted by the magnetic yoke member during the positioning of the device with respect to the yoke; a device for varying the magnetic forces present, whereby the magnetic attraction of the magnetic yoke member and/or the magnetic element on the magnets may be varied such that the magnetic force of attraction exerted by the yoke on the magnets becomes greater than that exerted by the magnetic element on them, thus provoking the transfer of the magnets to the yoke. The yoke member forms the magnetic path of a linear motor.

Claims

1. A method for positioning and affixing magnets to a magnetic yoke member of a motor, comprising:

arranging magnets on a face of a nonmagnetic support and maintaining the magnets in position on the nonmagnetic support by a force of attraction of a magnetic element, the magnetic element arranged on a side of the nonmagnetic support opposite to the face;

positioning the nonmagnetic support with respect to the magnetic yoke member with the magnets facing the magnetic yoke member and with the magnets held in position by the attraction of the magnetic element against a force of attraction of the magnetic yoke member, the force of attraction of the magnetic yoke member less than the force of attraction of the magnetic element;

varying magnetic forces acting on the magnets to at least one of (a) decrease the force of attraction of the magnetic element and (b) increase the force of attraction of the magnetic yoke element;

detaching the magnets from the nonmagnetic support;

attaching the magnets to the magnetic yoke member;

at least partially affixing the magnets on the magnetic yoke member; and

withdrawing the nonmagnetic support from the magnetic yoke member.

2. The method according to claim 1, further comprising:

before the positioning step, depositing glue on a face of the magnets to be glued to the magnetic yoke member so that, during the positioning of the nonmagnetic support, glue-covered faces of the magnets are oriented toward the magnetic yoke member;

wherein the at least partially affixing step includes gluing the magnets on the magnetic yoke member, the withdrawing step being performed after at least one of (a) sufficient drying and (b) sufficient polymerization of the glue to provide at least preliminary attachment of the magnets to the magnetic yoke member.

3. The method according to claim 1, wherein the varying step includes bringing together an assembly of the nonmagnetic support and the magnetic element, held together by a magnetic force of attraction of the magnets with the magnetic element of the magnetic yoke member of the motor.

4. The method according to claim 1, wherein the varying step includes separating the magnetic element from the nonmagnetic support.

5. The method according to claim 1, wherein the arranging and maintaining step includes increasing retention of the magnets in position on the nonmagnetic support by attractive effect of the magnetic element after arranging the magnets by bringing together the nonmagnetic support and the magnetic element.

6. A device for positioning and affixing magnets to a magnetic yoke member of a motor, comprising:

a nonmagnetic support adapted to receive the magnets, a shape of the nonmagnetic support complementary to a shape of the magnetic yoke member;

a magnetic element adapted to hold the magnets in position on the nonmagnetic support, the magnetic element arranged on an opposite side of the nonmagnetic support than the magnets, the magnetic element adapted to exert a magnetic attraction on the magnets greater than a magnetic attraction exerted by the magnetic yoke member during positioning of the device with respect to the magnetic yoke member; and

an arrangement adapted to vary at least one of (a) the magnetic attraction of the magnetic yoke member on the magnets and (b) the magnetic attraction of the magnetic element on the magnets to render the magnetic attraction of the magnetic yoke member on the magnets greater than the magnetic attraction of the magnetic element on the magnets.

7. The device according to claim 6, wherein the arrangement is adapted to displace the nonmagnetic support and the magnetic element in a direction of the magnetic yoke member to increase the magnetic attraction of the magnetic yoke member on the magnets.

8. The device according to claim 6, wherein the arrangement is adapted to displace the magnetic element to separate the magnetic element from the nonmagnetic support without reduction of a separation between the magnets and the magnetic yoke member.

9. The device according to claim 6, wherein the nonmagnetic support includes fins arranged on a disposition surface for the magnets adapted to retain the magnets in position.

10. The device according to claim 6, wherein the magnetic element is arranged as a lower part of a chassis, the chassis including vertical rods adapted to secure the magnetic element to an upper plate.

11. The device according to claim 10, wherein the nonmagnetic support is joined to a cap mounted to slide along the vertical rods of the chassis, the magnetic element arranged between the nonmagnetic support and an upper part of the cap.

12. The device according to claim 10, further comprising a housing vertically movable with respect to the chassis, the housing including an arrangement adapted to position the device on the magnetic yoke member during placement of the device on the magnetic yoke member, the housing adapted to rest against the magnetic yoke member.

13. The device according to claim 12, further comprising an arrangement adapted to displace the magnetic element and including a screw configured to cooperate with a thread in the upper plate to raise the upper plate and the magnetic element relative to the housing in accordance with turning of the screw.

14. The device according to claim 13, wherein a lower part of the screw is connected to a sleeve that extends vertically in a direction of the housing, the sleeve adapted to rest against the housing during turning of the screw.

15. The device according to claim 13, further comprising an arrangement adapted to maintain the nonmagnetic support in a lower position and near the magnetic yoke member when the magnetic element is raised.

16. A device for positioning and affixing magnets to a magnetic yoke member of a motor, comprising:

nonmagnetic support means for receiving the magnets, a shape of the nonmagnetic support means complementary to a shape of the magnetic yoke member;

magnetic means for holding the magnets in position on the nonmagnetic support means, the magnetic means arranged on an opposite side of the nonmagnetic support means than the magnets, the magnetic means exerting a magnetic attraction on the magnets greater than a magnetic attraction exerted by the magnetic yoke member during positioning of the device with respect to the magnetic yoke member; and

means for varying at least one of (a) the magnetic attraction of the magnetic yoke member on the magnets and (b) the magnetic attraction of the magnetic means on the magnets to render the magnetic attraction of the magnetic yoke member on the magnets greater than the magnetic attraction of the magnetic means on the magnets.