Linear motor system and compressor

Patent metadata

Field	Value
Publication number	US-11411522-B2
Application number	US-202016992218-A
Country	US
Kind code	B2
Filing date	Aug 13, 2020
Priority date	May 27, 2016
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

Controllability of a linear motor or a compressor is improved in a linear motor system that includes: an armature having magnetic poles and winding wires; a mover having a permanent magnet; and a power conversion unit that outputs AC power to the winding wires, in which the mover and the armature are relatively movable, and the mover or the armature is connected to an elastic body. The linear motor system further includes: a position detection unit that detects and outputs the position of the mover with respect to the armature, a position estimation, or a current detection unit that outputs the value of current flowing through the winding wires; and a control unit that controls the output of the power conversion unit on the basis of the output of the position detection unit, the output of the position estimation unit, or the output of the current detection unit.

First claim

The invention claimed is:

1. A compressor including an armature having magnetic poles and winding wires; a mover having a permanent magnet; a power conversion unit that outputs AC power to the winding wires, in which the mover and the armature are movable relative to each other, the mover or the armature is connected to an elastic body and a piston, and the piston compresses a fluid and a load caused by compressing the fluid changes in accordance with a phase or a drive frequency of the mover or the armature, the compressor comprising:
a position detection unit that detects and outputs a position of the mover or a position of the piston with respect to the armature, or a position estimation unit that estimates and outputs the position of the mover or the position of the piston with respect to the armature; and
a control unit that controls an output of the power conversion unit based on an output of the position detection unit or an output of the position estimation unit,
wherein the load is measured as pressure, temperature or discharge amount of the fluid and a frequency of the AC power is increased or decreased in correlation with the increase or decrease of the load, and
wherein the frequency of the AC power is controlled using an arctangent of a ratio of Fourier coefficients of the position of the mover with respect to the armature.

Assignees

• Hitachi Ltd

Inventors

• Suzuki Takahiro
• Nagata Shuhei
• Hatsuse Wataru
• Koyama Masaki

Classifications

• F04B35/04

  the means being electric · CPC title

• F04B2203/0404

  Frequency of the electric current · CPC title

• F04B49/06

  Control using electricity (regulating by means of floats actuating electric switches F04B49/04) · CPC title

• H02K41/031

  of the permanent magnet type · CPC title

• H02P25/064 Primary

  of the synchronous type · CPC title