HOISTING MACHINE INCLUDING A MEASURING ARRANGEMENT AND ELEVATOR SYSTEM CONTAINING THE SAME

• US 20130025977A1
• Filed: 10/10/2012
• Published: 01/31/2013
• Est. Priority Date: 09/25/2009
• Status: Active Grant

• Current Assignee: Kone Corporation
• Original Assignee: Kone Corporation
• Inventors: LAHTEENMAKI, Jussi, Tenhunen, Asmo, Huppunen, Jussi, Korhonen, Tuukka
• Granted Patent: US 8,596,420 B2
• Time in Patent Office: Days
• US Class Current: 187/394
• CPC Class Codes: B66B 1/3492 Position or motion detectors or driving means for the detector B66B1/40, B66B1/50 take precedence; length measuring G01B; speed measuring G01P
• CPC Class Codes: H02K 11/215 Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements
• CPC Class Codes: H02K 7/1008 structurally associated with the machine rotor H02K7/1012 takes precedence

Abstract

A measuring arrangement for the measurement of the position and/or movement of a rotor of an electricmachine, an electric drive including the measuring arrangement, and an elevator system including the electric drive are provided. The measuring arrangement includes a magnetic band whose magnetic property is so implemented that it varies in the longitudinal direction of the band.

Claims

1. A measuring arrangement for the measurement of the position and/or movement of the rotor of an electric machine, comprising:

a magnetic band, the magnetic property of said magnetic band being so implemented that the magnetic property varies in a longitudinal direction of the band,

wherein the magnetic band is attached to a rotating part of the electric machine, so that the magnetic band is fitted to revolve about a rotational axis of the rotor, and

wherein the measuring arrangement comprises a reader which senses the magnetic property varying in the longitudinal direction of the magnetic band, said reader being mounted on a stationary part of the electric machine in the immediate vicinity of the magnetic band.

2. The measuring arrangement according to claim 1, wherein the magnetic band has successive portions following each other in the longitudinal direction of the band, each two of said successive portions having mutually different magnetic properties.

3. The measuring arrangement according to claim 1, wherein the magnetic band has at least two parallel channels, each one of said channels containing successive portions following each other in the longitudinal direction of the band, and wherein different parallel channels differ from each other in respect of the disposition and/or frequency of occurrence of the said successive portions following each other.

4. The measuring arrangement according to claim 1, wherein the magnetic band is placed on a substantially circular ring around the rotational axis of the rotor.

5. The measuring arrangement according to claim 1, wherein the magnetic fields generated by two successive portions following each other in the longitudinal direction of the magnetic band differ from each other in respect of intensity.

6. The measuring arrangement according to claim 1, wherein the magnetic fields generated by two successive portions following each other in the longitudinal direction of the magnetic band are oriented in mutually opposite directions.

7. The measuring arrangement according to claim 1, wherein the intensity of the magnetic field generated by the magnetic band varies in the longitudinal direction of the band substantially sinusoidally.

8. The measuring arrangement according to claim 1, wherein the reader is arranged to produce a measurement signal on the basis of the magnetic property and/or change in the magnetic property of the magnetic band portion located in the immediate vicinity of the reader.

9. The measuring arrangement according to claim 1, wherein the measuring arrangement comprises a magnetic-band reading circuit, which has an input for the measurement signal produced by the reader sensing the magnetic property, and which reading circuit has an output for data representing the position and/or movement of the rotor of the electric machine.

10. An electric drive comprising:

an electric machine; and

a frequency converter for producing a variable-amplitude and variable-frequency supply voltage for controlling the electric machine,

wherein the measuring arrangement according to claim 1 is fitted in the electric machine for measuring the position and/or movement of the rotor of the electric machine.

11. An elevator system, comprising the electric drive according to claim 10 for controlling the movement of the elevator car, wherein an elevator control unit is arranged to determine the position of the elevator car in the elevator shaft, using for this determination the data detected by the magnetic band reader representing the movement and/or position of the rotor of the electric machine.

12. The measuring arrangement according to claim 2, wherein the magnetic band has at least two parallel channels, each one of said channels containing successive portions following each other in the longitudinal direction of the band, and wherein different parallel channels differ from each other in respect of the disposition and/or frequency of occurrence of the said successive portions following each other.

13. The measuring arrangement according to claim 2, wherein the magnetic band is placed on a substantially circular ring around the rotational axis of the rotor.