JPH07317673A - Screw fluid machine - Google Patents

Abstract

PURPOSE:To facilitate the timing setting work and prevent the corrosion of motor windings. CONSTITUTION:Rotors 5A, 5B are overhung and fixed at one shaft end of both rotary shafts 6A, 6B, timing gears 7A, 7B are overhung and fixed at the other end, and a motor rotor 10 is fixed between the upper bearing 8A and the lower bearing 9A of one rotary shaft 6A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw fluid machine in which rotors engage with each other in a non-contact state around two parallel axes to rotate synchronously, and both ends of both rotary shafts are rotatably supported by bearings. .

[0002]

2. Description of the Related Art In such a conventional screw fluid machine, a timing gear is provided in the middle of both bearings of both rotary shafts.

Further, the motor stator chamber is open to the rotor side.

[0004]

Therefore, in order to set the timing of both rotors, it is necessary to set the rotor on the rotary shaft and set the rotary shaft to the normal state with both bearings. It was difficult to set the timing when there was between both bearings.

When a corrosive gas such as a semiconductor manufacturing apparatus is sucked as a vacuum pump, the corrosive gas may enter the motor stator chamber and corrode the winding of the motor.

It is an object of the present invention to provide a screw fluid machine which facilitates the timing setting work and prevents corrosion of the motor winding.

[0007]

According to the invention, the parallel two
In a screw fluid machine in which rotors provided in a casing mesh with each other in a non-contact state around shafts and rotate synchronously, and both rotary shafts are rotatably supported by two bearings, respectively. A rotor is overhung and fixed to one shaft end, a timing gear is overhung and fixed to the other shaft end, and a motor rotor is fixed between both bearings of one rotating shaft.

Further, according to the present invention, the motor stator casing is detachably attached to the central casing with bolts.

Further, according to the present invention, both rotary shafts are formed in the same shape.

[0010]

In the screw fluid machine configured as described above, the rotor is set on both rotary shafts, both rotary shafts are supported by both bearings in a normal state, and the timing is easily set by setting the timing gear. Can be installed.

Further, since the motor stator casing can be easily formed into a can structure and the motor stator chamber can be isolated from the motor chamber and opened to the atmosphere, the lead wire can be easily taken out and the motor can be removed. It is possible to prevent the corrosive gas from entering the stator chamber.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2, the entire casing of the screw fluid machine, that is, the screw pump, is designated by reference numeral A. The casing comprises a rotor casing 1, a central casing 2, a lower casing 3 and a bottom cover 4. On a part of the lower surface of the central casing 2, a motor stator casing 12 of a motor stator 11 containing a motor rotor 10 is detachably attached with bolts 20 (see FIG. 3). The rotary shaft 6A is rotatably supported by the central casing 2 and the motor stator casing 12 by an upper bearing 8A and a lower bearing 9A.
A prevents the oil that lubricates the bearing from entering the pump chamber B. On the other hand, a rotary shaft 6B having the same shape as the rotary shaft 6A is rotatably supported by the central casing 2 and the lower casing 3 by an upper bearing 8B and a lower bearing 9B, and oil that lubricates the bearing by the shaft sealing device 18B is pump chamber. B is prevented from invading.

Then, at the upper ends of both rotary shafts 6A and 6B,
The rotors 5A and 5B are overhangingly fixed so as to mesh with each other in a non-contact manner. On the other hand, timing gears 7A and 7B meshing with each other are fixed to the lower ends of both rotary shafts 6A and 6B by overhanging and are covered with a bottom cover 4. Further, a motor rotor 10 is fixedly provided between the one rotating shaft 6A and the upper bearing 8A and the lower bearing 9A.

The motor stator chamber D is open to the atmosphere through a passage 17, and the lead wire 15 is drawn out. Reference numeral 13 in the drawing indicates a can, which divides the motor rotor chamber C and the motor stator chamber D. 1
Reference numeral 4 is a water-cooled room by passing water.

Next, the operation will be described.

In assembly, first, the rotary shaft 6A having the motor rotor 10 fixed thereto is attached to the central casing 2 via the bearing 8A, and then the motor stator casing 12 is fixed to the central casing 2 from below with bolts or the like. After supporting the rotary shaft 6A in a normal state via the bearing 9A, the rotor 5A is mounted.

On the other hand, the rotary shaft 6B is mounted on the central casing 2 via the bearing 8B, then the lower casing 3 is mounted on the central casing 2, the rotary shaft 6B is supported by the bearing 9B, and the rotor 5B is mounted. In this state, the rotary shaft 6A,
The timing gears 7A and 7B are attached to the lower end of 6B, and the timing gears 7A and 7B are fixed by adjusting the rotors 5A and 5B so that they mesh with each other with a proper gap. At this time, the timing gears 7A and 7B are exposed at the shaft end,
Since there are no parts around the timing setting work, it can be set very easily.

After that, the rotor casing 1 and the bottom cover 4
Install and finish the assembly.

The motor rotor chamber C has a shaft sealing device 18
Although it is sealed from pump chamber B by A and 18B,
It is conceivable that the corrosive gas in the pump chamber B may enter the motor rotor chamber C when the pressure in the pump chamber B varies depending on the operating conditions. However, since the motor stator chamber D is isolated from the pump chamber B by the can structure, the motor winding can be protected from corrosion. Moreover, since the motor stator casing 12 is a separate body that can be detached from the pump casing, it can be easily manufactured in a can structure.

When the corrosive gas may corrode the motor rotor 10, the motor rotor 10 may be covered with a can.

Further, both rotary shafts 6A and 6B are formed in the same shape even though the motor rotor is fixedly mounted on only one of them, so that the cost can be reduced by the effect of mass production.

[0023]

Since the present invention is constructed as described above, it has the following effects.

(1) The timing setting work can be easily performed.

(2) The motor stator casing can be easily manufactured to have a can structure, the corrosive gas can be prevented from entering the motor stator chamber, and the winding corrosion can be prevented.

(3) The cost of both rotary shafts can be reduced by mass production.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a side sectional view showing a lead wire lead portion.

FIG. 3 is a mounting view of the motor stator casing viewed in the MM direction in FIG.

[Explanation of symbols]

 A ... Pump casing B ... Pump chamber C ... Motor rotor chamber D ... Motor stator chamber 1 ... Rotor casing 2 ... Central casing 3 ... Lower casing 4 ... Bottom cover 5A 5B ... Rotor 6A, 6B ... Rotating shaft 7A, 7B ... Timing gear 8A, 8B ... Upper bearing 9A, 9B ... Lower bearing 10 ... Motor rotor 11 ... Motor stator 12・ ・ ・ Motor stator casing 13 ・ ・ ・ Can 14 ・ ・ ・ Water cooling chamber 15 ・ ・ ・ Lead wire 16 ・ ・ ・ Sealing member 17 ・ ・ ・ Passages 18A, 18B ・ ・ ・ Shaft sealing device 20 ・ ・ ・ Motor stator casing Mounting bolts

Claims (3)

[Claims] 1. A screw fluid machine in which two rotors are rotatably supported by two bearings, respectively, in which rotors provided in a casing mesh with each other in a non-contact state around two parallel shafts to rotate synchronously. In above, a rotor is overhung and fixed to one shaft end of each rotary shaft, and a timing gear is overhung and fixed to the other shaft end, and a motor rotor is provided between both bearings of one rotary shaft. A screw fluid machine characterized by having a fixed. 2. The screw fluid machine according to claim 1, wherein the motor stator casing is detachably attached to the central casing with bolts. 3. The screw fluid machine according to claim 1, wherein both rotary shafts have the same shape.