Magnetic screw propulsion system for elevators

Patent metadata

Field	Value
Publication number	US-9878881-B2
Application number	US-201214443780-A
Country	US
Kind code	B2
Filing date	Nov 20, 2012
Priority date	Nov 20, 2012
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A propulsion system includes a magnetic screw having a first magnetic element having a first polarity, the first magnetic element arranged along a first non-linear path along a longitudinal axis of the magnetic screw and a second magnetic element having a second polarity, the second magnetic element arranged along a second non-linear path along the longitudinal axis of the magnetic screw; a motor for rotating the magnetic screw about the longitudinal axis; and a stator made from a ferrous material, the stator having a body with an internal cavity, the body including a plurality of poles extending into the cavity, the poles arranged along a pole non-linear path along a longitudinal axis of the stator.

First claim

The invention claimed is:

1. A propulsion system comprising:
a magnetic screw having a first magnetic element having a first polarity, the first magnetic element arranged along a first non-linear path along a longitudinal axis of the magnetic screw and a second magnetic element having a second polarity, the second magnetic element arranged along a second non-linear path along the longitudinal axis of the magnetic screw;
a motor for rotating the magnetic screw about the longitudinal axis; and
a stator made from a ferrous material, the stator having a body with an internal cavity, the body including a plurality of poles extending into the cavity, the poles arranged along a pole non-linear path along a longitudinal axis of the stator;
a backup propulsion system having a mechanical screw, wherein the mechanical screw can engage the stator.

2. The propulsion system of claim 1 wherein: at least one of the first non-linear path, the second non-linear path and the pole non-linear path is helical.

3. The propulsion system of claim 1 wherein: the first magnetic element includes a strip permanent magnet having a surface with the first polarity facing away from the magnetic screw.

4. The propulsion system of claim 1 wherein: the first magnetic element includes a plurality of first permanent magnets arranged along the first non-linear path, the plurality of first permanent magnets having a surface with the first polarity facing away from the magnetic screw.

5. The propulsion system of claim 4 wherein: the second magnetic element includes a plurality of second permanent magnets arranged along the second non-linear path, the plurality of second permanent magnets having a surface with the second polarity facing away from the magnetic screw.

6. The propulsion system of claim 1 wherein: the first magnetic element includes a first strip of ferrous material adjacent to a first pole of a permanent magnet.

7. The propulsion system of claim 6 wherein: the second magnetic element includes a second strip of ferrous material adjacent to a second pole of the permanent magnet.

8. A propulsion system comprising:
a magnetic screw having a first magnetic element having a first polarity, the first magnetic element arranged along a first non-linear path along a longitudinal axis of the magnetic screw and a second magnetic element having a second polarity, the second magnetic element arranged along a second non-linear path along the longitudinal axis of the magnetic screw;
a motor for rotating the magnetic screw about the longitudinal axis; and
a stator made from a ferrous material, the stator having a body with an internal cavity, the body including a plurality of poles extending into the cavity, the poles arranged along a pole non-linear path along a longitudinal axis of the stator;
wherein at least one end of the magnetic screw is tapered in diameter to provide an increased airgap between the magnetic screw and the stator at the tapered end.

9. An elevator propulsion system comprising:
a magnetic propulsion assembly configured for connection to an elevator car, the magnetic propulsion assembly including:
a magnetic screw having a first magnetic element having a first polarity, the first magnetic element arranged along a first non-linear path along a longitudinal axis of the magnetic screw and a second magnetic element having a second polarity, the second magnetic element arranged along a second non-linear path along the longitudinal axis of the magnetic screw;
a motor for rotating the magnetic screw about the longitudinal axis to impart motion to the elevator car;
a brake for stopping rotation of the magnetic screw; and
a stator made from a ferrous material, the stator having a body with an internal cavity, the body including a plurality of poles extending into the cavity, the poles arranged along a pole non-linear path along a longitudinal axis of the stator;
a backup propulsion system having a mechanical screw, wherein the mechanical screw can engage the stator.

10. The elevator propulsion system of claim 9 wherein: at least one of the first non-linear path, the second non-linear path and the pole non-linear path is helical.

11. The elevator propulsion system of claim 9 wherein: the first magnetic element includes a strip permanent magnet having a surface with the first polarity facing away from the magnetic screw.

12. The elevator propulsion system of claim 9 wherein: the first magnetic element includes a plurality of first permanent magnets arranged along the first non-linear path, the plurality of first permanent magnets having a surface with the first polarity facing away from the magnetic screw.

13. The elevator propulsion system of claim 12 wherein: the second magnetic element includes a plurality of second permanent magnets arranged along the second non linear path, the plurality of second permanent magnets having a surface with the second polarity facing away from the magnetic screw.

14. The elevator propulsion system of claim 9 wherein: the first magnetic element includes a first strip of ferrous material adjacent to a first pole of a permanent magnet.

15. The elevator propulsion system of claim 14 wherein: the second magnetic element includes a second strip of ferrous material adjacent to a second pole of the permanent magnet.

16. The elevator propulsion system of claim 9 wherein: the motor and the brake are positioned within the internal cavity of the stator.

17. An elevator propulsion system comprising:
a magnetic propulsion assembly configured for connection to an elevator car, the magnetic propulsion assembly including:
a magnetic screw having a first magnetic element having a first polarity, the first magnetic element arranged along a first non-linear path along a longitudinal axis of the magnetic screw and a second magnetic element having a second polarity, the second magnetic element arranged along a second non-linear path along the longitudinal axis of the magnetic screw;
a motor for rotating the magnetic screw about the longitudinal axis to impart motion to the elevator car; and
a brake for stopping rotation of the magnetic screw; and a stator made from a ferrous material, the stator having a body with an internal cavity, the body including a plurality of poles extending into the cavity, the poles arranged along a pole non-linear path along a longitudinal axis of the stator;
wherein at least one end of the magnetic screw is tapered in diameter to provide an increased airgap between the magnetic screw and the stator at the tapered end.

18. An elevator system comprising:
an elevator car for travel in a hoistway;
a magnetic propulsion assembly coupled to the elevator car, the magnetic propulsion assembly including:
a magnetic screw having a first magnetic element having a first polarity, the first magnetic element arranged along a first non-linear path along a longitudinal axis of the magnetic screw and a second magnetic element having a second polarity, the second magnetic element arranged along a second non-linear path along the longitudinal axis of the magnetic screw;
a motor for rotating the magnetic screw about the longitudinal axis to impart motion to the elevator car;
a brake for stopping rotation of the magnetic screw;
a stator positioned along a length of the hoistway, the stator made from a ferrous material, the stator having a body with an internal cavity, the body including a plurality of poles extending into the cavity, the poles arranged along a pole non-linear path along a longitudinal axis of the stator;
a backup propu

Assignees

• Otis Elevator Co

Inventors

• Fargo Richard N

Classifications

• H02K41/00

  Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path {(electromagnetic launchers F41B6/00)} · CPC title

• B66B11/0407

  actuated by an electrical linear motor (in the counterweight B66B17/12) · CPC title

• H02K49/102

  Magnetic gearings, i.e. assembly of gears, linear or rotary, by which motion is magnetically transferred without physical contact (magnetized gearings with physical contact F16H13/12, F16H49/005) · CPC title

• H02K7/06 Primary

  Means for converting reciprocating motion into rotary motion or vice versa · CPC title

• B66B11/0438 Primary

  with a gearless driving, e.g. integrated sheave, drum or winch in the stator or rotor of the cage motor · CPC title