Motor system and compressor equipped therewith

Patent metadata

Field	Value
Publication number	US-10288117-B2
Application number	US-201515541863-A
Country	US
Kind code	B2
Filing date	Jan 7, 2015
Priority date	Jan 7, 2015
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

To provide a motor system that can control the position of a control object in multiple directions while suppressing the number of required switching elements. A motor system includes: a power conversion device including first, second, and third up-down arms each including two switching elements connected in series; a control object; and a first load including a magnetic pole tooth facing the control object, and a winding wound around the magnetic pole tooth. The motor system includes a second load including two magnetic pole teeth facing each other in a second direction with the control object therebetween, and a winding wound around one or both of the magnetic pole teeth. The power conversion device provides a force with respect to a first direction to the control object through an output to the first load, and provides a force with respect to the second direction to the control object through an output to the second load.

First claim

The invention claimed is:

1. A motor system comprising:
a power conversion device including first, second, and third up-down arms each including two switching elements connected in series;
a control object; and
a first load including a magnetic pole tooth facing the control object, and a winding wound around the magnetic pole tooth, wherein
the motor system includes a second load including two magnetic pole teeth facing each other in a second direction with the control object therebetween, and a winding wound around one or both of the magnetic pole teeth, and
the power conversion device
provides a force with respect to a first direction to the control object through an output to the first load, and
provides a force with respect to the second direction to the control object through an output to the second load; and

wherein
the power conversion device
connects the first up-down arm and the second up-down arm to the first load,
connects the second up-down arm and the third up-down arm to the second load,
outputs a sinusoidal AC signal or rectangular-wave AC signal to the first load, and
outputs a positive-negative variable DC signal or constant signal to the second load.

2. The motor system according to claim 1 , further comprising a DC voltage source and a voltage dividing resistor connected in parallel to the DC voltage source, wherein
the motor system includes three first loads,
respective one end sides of the three first loads are respectively connected to the three up-down arms,
the respective other end sides of the three first loads are connected to each other to form a neutral point,
the power conversion device outputs a symmetrical three-phase AC signal to the three first loads,
one end side of the second load is connected to the neutral point, and
the other end side of the second load is connected between two resistors belonging to the voltage dividing resistor.

3. The motor system according to claim 1 , further comprising:
a position detection unit that detects or estimates a position of the control object with respect to the first direction;
an eccentricity/inclination detection unit that detects or estimates a position or inclination of the control object with respect to the second direction; and
a control unit that changes an amplitude, frequency, or offset of output signals to the first load and the second load according to outputs of the position detection unit and the eccentricity/inclination detection unit.

4. The motor system according to claim 1 , wherein
the first load and the second load are arranged in the first direction,
the control object includes a permanent magnet capable of facing the first load and a permanent magnet capable of facing the second load, and
the permanent magnet capable of facing the second load has a flat-plate shape having a width in a third direction.

5. A compressor comprising:
the motor system according to claim 1 ;
a piston provided on one end side of the control object and capable of performing reciprocating motion in the first direction; and
a cylinder on which the piston slides, wherein
the second load is provided on the other end side of the control object.

Assignees

• Hitachi Ltd

Inventors

• Suzuki Takahiro
• Aoyama Yasuaki
• Nagata Shuhei
• Koyama Masaki

Classifications

• H02K11/21

  Devices for sensing speed or position, or actuated thereby (specially adapted for machines having non-mechanical commutating devices H02K29/06, H02K29/14) · CPC title

• F04B35/045

  using solenoids · CPC title

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• H02P25/064

  of the synchronous type · CPC title

• H02K7/09

  with magnetic bearings · CPC title