JP2909951B2 - GM refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GM refrigerator, and is used, for example, for a cryopump required for a semiconductor manufacturing process.

[0002]

2. Description of the Related Art As a prior art related to the present invention, for example, a catalog "AISIN CRYOPUMP Aisin Cryopump Series (9006-5000NH)"
There is one issued by Aisin Seiki Co., Ltd. The GM refrigerator used in the cryopump according to the prior art will be described. The configuration mainly includes a compressor unit, an expansion unit connected to the compressor unit via piping, and a pressure of the expansion unit. And a motor that drives the piston and the valve mechanism that constitute the regenerator.

A conventional technique for controlling the motor of the refrigerator is disclosed in, for example, JP-A-4-60179. The commercial power supply transmits three-phase alternating current. However, since a two-phase synchronous motor is used for the motor, a phase converter such as a Scott connection transformer (three-phase to two-phase) is used.
Phase) is always required. Therefore, a large space is required for the phase converter, and the cost is increased due to the connection between the motor and the phase converter.

Further, a single-phase AC power source is converted into two phases by a capacitor, and the rotor is rotated and moved by 1.8 degrees per one AC waveform (one pulse), thereby controlling a type of obtaining a predetermined rotation speed. In the two-phase synchronous motor to be performed, the waveform of the phase shifted by the capacitor is far from the sine wave, and a periodic imbalance occurs in the electromagnetic force for moving the rotor of the motor, causing vibration.

[0005] The GM refrigerator is incorporated in a cryopump used in a semiconductor manufacturing process. With the recent increase in the degree of integration of semiconductors, there is an increasing demand for vibration reduction of the cryopump. Vibration of lower frequency is more easily transmitted from the cryopump to the semiconductor manufacturing apparatus, and the two-phase synchronous motor has a large vibration peak at 500 Hz or less. For this reason, in a GM refrigerator using a two-phase synchronous motor, as a measure to reduce the amount of vibration transmission, a bellow is used for the cryopump case, a disk is attached to impart inertia to the motor shaft, or a semiconductor is used. For example, a vibration isolator was added to the manufacturing apparatus. However, in either case, cost increases cannot be avoided, and the installation space increases.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the vibration of a GM refrigerator.

[0007]

In order to solve the above-mentioned problems, the present invention provides a compressor unit, an expansion unit connected to the compressor unit via a refrigerant pipe, and a pressure of the expansion unit. a valve mechanism for controlling, in the GM refrigerator having a motor for driving the piston and the valve mechanism constituting the cold accumulating material, thereby forming the motor in three-phase synchronous motor, the three-phase synchronous motor
The GM refrigerator is characterized by supplying a three-phase power to the heater .

[0008]

According to the above means, the refrigerant is pressure-fed from the compressor unit to the expansion section via the refrigerant pipe, and the motor consisting of the three-phase synchronous motor operates the valve mechanism and the piston, thereby storing the refrigerant in the cold storage. After being pre-cooled by the body, it is adiabatically expanded in the expansion section to generate cold heat.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.
The GM refrigerator 10 is used as a cryopump (not shown), that is, a vacuum pump refrigerator.
1, a refrigerant pipe 12, an expansion portion 13, and a motor 14. In particular, the expansion portion 13 and the motor 14 are integrally arranged as a pump unit 15.

First, the compressor unit 11 will be described. The compressor unit 11 is a low-pressure refrigerant gas (for example, H
e) performs cooling and oil separation by sucking / compressing e) and supplies clean high-pressure refrigerant gas to the pump unit 15, and mainly includes a compressor (not shown), a discharge gas and an oil cooler, an oil separator, an adsorber, and the like. Is done.

The refrigerant pipe 12 includes a suction pipe 12a and a discharge pipe 12b.

The expansion section 13 has a cold head 13a, to which an adsorption panel or a cryopanel (not shown) of the cryopump is thermally coupled. The cryopanel is exposed in a space to be evacuated, and gas molecules in this space are condensed and adsorbed by cold heat.
The expansion portion has an expansion piston (not shown) therein to define an expansion space, and a regenerator (not shown) is provided in the expansion piston.

In the pump unit 15, a valve mechanism 2 is provided.
1, a suction valve and a discharge valve (not shown) are provided.

The motor 14 opens and closes the valve mechanism 21 and reciprocates the expansion piston up and down. The torque of the motor 14 is transmitted to the expansion piston via a rotation / reciprocation conversion mechanism such as a scotch yoke mechanism. Is done. The motor 14 comprises a three-phase synchronous motor, and a three-phase commercial power supply 16 (generally, 200 V AC)
Are connected via the control device 17.

The GM refrigerator 10 having the above configuration
The operation is started by turning on an operation switch (not shown), the clean high-pressure refrigerant gas discharged from the compressor unit 11 flows through the discharge side pipe 12b, and the suction valve in the pump unit 15 is operated by the motor 14 by the motor 14. By being opened, it is supplied to the expansion space of the expansion section 13, and by opening the suction valve after closing the discharge valve, adiabatic expansion of the high-pressure refrigerant gas generates cold heat. This cold heat is cold head 13
Gas is condensed and adsorbed on each panel from a through an adsorption panel or a cryopanel. Then, the refrigerant gas that has expanded to a low pressure is sucked into the compressor unit 11 from the suction side pipe 12a by opening the discharge valve in the pump unit 15. Various components are electronically controlled by a control unit (not shown).

By using a three-phase synchronous motor, a larger torque can be extracted than in a conventional two-phase synchronous motor, so that the motor can be used irrespective of the size of the GM refrigerator and cost reduction can be expected.

[0017]

According to the present invention, since a three-phase synchronous motor is used for the motor of the GM refrigerator, three-phase commercial power can be supplied to the motor only through a control device without a phase converter. In addition, the configuration between the power supply and the motor can be simplified.

The three-phase synchronous motor is driven by the supply of three-phase power from a three-phase commercial power supply, and rotates the rotor by 1.2 degrees per pulse, and the sinusoidal waveform of each phase is the same. This is a wave and can suppress the generation of an unbalanced periodic excitation force generated by the two-phase synchronous motor. Therefore, when the GM refrigerator is used for a device that dislikes vibration (for example, a cryopump used in a semiconductor manufacturing device), it is not necessary to employ a vibration transmission preventing structure for the device, and the overall structure is simple, inexpensive, and highly reliable. Can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a GM refrigerator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Compressor unit 12 Refrigerant piping 13 Expansion part 14 Motor 21 Valve mechanism

Claims (1)

(57) [Claims] 1. A compressor unit, an expansion unit connected to the compressor unit via a refrigerant pipe, a valve mechanism for controlling the pressure of the expansion unit, a piston constituting a regenerator, and the valve mechanism. A GM refrigerator having a driving motor, wherein the motor is constituted by a three-phase synchronous motor, and the three-phase synchronous motor is provided with a three-phase synchronous motor.
A GM refrigerator characterized by supplying power .