Split magnet drive

• US 4,163,164 A
• Filed: 10/11/1977
• Issued: 07/31/1979
• Est. Priority Date: 10/11/1977
• Status: Expired due to Term

• Current Assignee: Micropump, Inc. (RELX PLC)
• Original Assignee: Micropump, Inc. (RELX PLC)
• Inventors: Pieters, Ferdinandus A.
• Primary Examiner(s): Duggan, Donovan F.
• Application Number:
  US05/841,034
• Time in Patent Office: 658 Days
• Field of Search: 310/103, 310/105
• US Class Current: 310/103
• CPC Class Codes: F04D 13/026 Details of the bearings
• CPC Class Codes: F04D 13/027 Details of the magnetic circuit
• CPC Class Codes: H02K 49/106 with a radial air gap
• CPC Class Codes: H02K 5/128 using air-gap sleeves or air-gap discs

Abstract

One of two permanent magnets used to drive pumps and the like is split--i.e., the annular permanent magnet is split into two annular members, one fixed to one of the rotating members, the other freely rotatable independent of the other. The structure provides for recoupling without having to stop the driving magnet when decoupling has occurred. It also provides free travel and/or dynamic damping to alleviate oscillation and sporadic decoupling.

The member fixed for rotation is a permanent magnet; the other is preferably a permanent magnet but may also be of a material which is magnetically permeable, in which case damping only is accomplished.

Claims

1. A magnetic drive comprising an annular first magnet, an annular second magnet in driving proximity to said first magnet, drive means for driving said first magnet, drive means driven by said second magnet, and an annular control member in proximity to one of said magnets, said control member being independent of rotation of said driven means, said control member having at least one position of movement when said control magnet is in frictional contact with one of said magnets, said first and second magnets each having a plurality of magnetic poles.

2. A drive according to claim 1 in which said control member is magnetically permeable.

3. A drive according to claim 1 in which said control member is a magnet having a plurality of poles.

4. A drive according to claim 3 in which said control member is axially aligned and in proximity to said second magnet.

5. A drive according to claim 4 in which both said second magnet and said control member are inside said first magnet and magnetically attracted by said first magnet, said control member being axially movable toward and away from said second magnet.

6. A drive according to claim 4 in which said control member is remote from magnetic influence by said first magnet but is in frictional contact with said second magnet.

7. A drive according to claim 6 which further comprises non-magnetizable mass rotatably connected to said control member, said control member being positioned to frictionally dampen said second magnet.

8. A drive according to claim 1 in which said control member is a magnet in frictional contact with said one of said magnets but remote from magnetic influence by the other of said magnets.

9. A drive according to claim 8 which further comprises an annular second control member, said second control member being a multi-pole magnet in frictional contact with said other of said magnets but remote from magnetic influence by the said one of said magnets.

10. A drive according to claim 9 which further comprises a mass rotatably connected to one of said control members, each said control member being positioned to frictionally dampen one of said magnets.