ENHANCED DECELERATION PROPULSION SYSTEM FOR ELEVATORS

• US 20150353321A1
• Filed: 01/17/2013
• Published: 12/10/2015
• Est. Priority Date: 01/17/2013
• Status: Active Grant

• Current Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Original Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Inventors: Fargo, Richard N.
• Granted Patent: US 10,087,044 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B66B 1/285 with the use of a speed pattern generator
• CPC Class Codes: B66B 1/30 effective on driving gear , e.g. acting on power electronics, on inverter or rectifier controlled motor
• CPC Class Codes: B66B 11/0407 actuated by an electrical linear motor in the counterweight B66B17/12
• CPC Class Codes: B66B 5/02 responsive to abnormal operating conditions
• CPC Class Codes: B66B 5/22 by means of linearly-movable wedges B66B5/24 takes precedence
• CPC Class Codes: Y02B 50/00 Energy efficient technologies in elevators, escalators and moving walkways, e.g. energy saving or recuperation technologies

Abstract

An elevator system includes a first propulsion system for imparting linear motion to an elevator car; a controller generating control signals for the first propulsion system; a brake for holding the elevator car; an energy storage unit; and a second propulsion system; the controller configured to at least one of (i) access the energy storage unit to power at least one of the first propulsion system and second propulsion system upon a fault during upward travel of the elevator car (ii) power the second propulsion system upon a fault in the first propulsion system during upward travel of the elevator car and (iii) delay applying the brake until the elevator car speed is less than a threshold upon a fault during upward travel of the elevator car.

Claims

1. An elevator system comprising:

a first propulsion system for imparting linear motion to an elevator car;

a controller generating control signals for the first propulsion system;

a brake for holding the elevator car;

an energy storage unit; and

a second propulsion system;

the controller configured to at least one of (i) access the energy storage unit to power at least one of the first propulsion system and second propulsion system upon a fault during upward travel of the elevator car (ii) power the second propulsion system upon a fault in the first propulsion system during upward travel of the elevator car and (iii) delay applying the brake until the elevator car speed is less than a threshold upon a fault during upward travel of the elevator car.

2. The elevator system of claim 1 wherein:

the controller is configured to access the energy storage unit to power the first propulsion system upon a loss of power.

3. The elevator system of claim 1 wherein:

the controller is configured to drive the second propulsion system upon a fault in the first propulsion system.

4. The elevator system of claim 1 wherein:

upon a fault, the controller controls at least one of the first propulsion system and the second propulsion system to provide elevator car deceleration of less than 9.8 m/s².

5. The elevator system of claim 1 wherein:

the energy storage unit includes at least one of a capacitor, a battery and a flywheel.

6. The elevator system of claim 1 wherein:

the energy storage unit is configured to store more than about 20,000 Joules of energy.

7. An elevator system comprising:

an elevator car;

a guide rail; and

a linear synchronous reluctance motor including;

a primary circuit having a plurality of primary poles and windings about the primary poles;

a secondary circuit having a plurality of secondary poles;

the primary circuit coupled to one of the elevator car and the guide rail, the secondary circuit coupled to the other of the elevator car and the guide rail.

8. The elevator system of claim 7 wherein:

the primary circuit is mounted to the elevator car.

9. The elevator system of claim 7 wherein:

a pitch of the primary poles matches a pitch of the secondary poles.

10. The elevator system of claim 7 wherein:

the secondary poles are formed in the guide rail.

11. The elevator system of claim 10 wherein:

the primary poles include a first primary pole positioned on a first side of the guide rail and a second primary pole positioned on a second side of the guide rail.

12. The elevator system of claim 10 wherein:

the guide rail includes guide surfaces for guiding the elevator car along a hoistway.

13. A unidirectional brake for an elevator, the unidirectional brake comprising:

a safety block having a tapered wedge guide for placement about an elevator guide rail;

a wedge configured to apply a braking force to the guide rail only upon downward movement of the elevator car; and

a biasing member configured to assume an extended position and a retracted position, the biasing member positioning the wedge in the wedge guide when the biasing member is in the extended position.

14. The unidirectional brake of claim 13 further comprising:

an actuator configured to selectively position the biasing member between the extended position and the retracted position.

15. The unidirectional brake of claim 14 wherein:

the actuator places the biasing member in the extended position upon a fault.

16. The unidirectional brake of claim 13 further comprising:

a second wedge configured to apply a braking force to the guide rail only upon downward movement of the elevator car.