JPH06346881A - Two-stage oil-free screw compressor - Google Patents

Abstract

(57) [Summary] [Structure] The one-stage compressor body and the two-stage compressor body are arranged above the gear casing 3, and the gear casing oil sump portion 24 and the gear casing side frame 25 are disposed below the compressor body. A motor was arranged in the middle, a V-belt speed-up drive device was provided, and a gear casing assembly accommodating drive system components was fixed on the base 6 with a vibration-proof rubber 30. Further, a belt tension adjusting device including a motor base 28 having a hinge mechanism is provided. [Effect] The speed increasing device can be downsized and the cost can be reduced, and the vibration propagating from the vibration source to the base can be blocked to reduce the noise of the compressor. Further, the maintainability and durability of the belt tension adjusting device can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw compressor, and more particularly to a speed increasing mechanism and a vibration isolating structure for a small capacity and medium capacity two-stage oilless screw compressor.

[0002]

2. Description of the Related Art In the prior art, as disclosed in Japanese Patent Laid-Open No. 3-151592, there is an example in which a gear shaft in a gear casing and a motor are directly connected by a coupling. In this conventional technology, the speedup ratio between the pinion gear and the bull gear is increased because the belt is not accelerated, and the gear casing that houses the bull gear and the bull gear is made larger. Therefore, the types of speed-up gears increase and the cost increases.

As a conventional technique, Japanese Patent Laid-Open No. 316555/1989
In order to simplify the method of adjusting the tension of the compressor V belt, the shape of the motor bolt is made special, and the belt tension adjustment work is simplified by combining the tension bolts. However, there is a drawback that the adjustment mechanism is complicated and the number of parts for adjustment is large.

[0004]

The main object of the present invention is to:
It is to realize simplification and cost reduction of the speed increasing device of the compressor, and further to reduce the noise value and the vibration value of the compressor.
Another object of the present invention is to improve maintainability such as belt tension adjustment and further improve the durability of the belt tension adjusting device.

[0005]

In order to achieve the above-mentioned object, a low pressure stage side compressor body, a high pressure stage side compressor body, and a drive device for driving both compressor bodies such as a speed increasing gear and an electric motor. In a two-stage oil-free screw compressor including a gear casing that houses a speed-increasing gear, the low-pressure stage side compressor body and the high-pressure stage side compressor body are placed on top of the gear casing, and the oil on the side surface of the gear casing. A sump is provided, a side frame is provided on the other side surface, and an electric motor is arranged below the compressor main body and between the oil sump and the side frame, and further comprises an M sheave, a V pulley, and a motor base. A V-belt speed-up drive device is provided. Further, the gear casing assembly containing the drive system components was fixed on the base via a vibration isolator.

Further, in the two-stage compressor, the side end of a plate-shaped motor base having a hinge hole is fixed to the gear casing with a hinge bolt, and the other side end of the motor base is fixed to the gear casing with a supporting bolt. In addition, a hinge mechanism that can be rotated and fixed around the motor base and hinge bolts is provided. Furthermore, self-lubrication is applied to the hinge part of the motor base, the support bolt and hinge part, the contact part of the motor base hinge part and the gear casing. The bush or sleeve having the property is provided.

[0007]

The vibration source of the two-stage oil-free screw compressor has pulsating gas torque due to the meshing of the male rotor and female rotor, the internal backlash of the bearing, the bull gear, and the imbalance of the rotating body such as the M sheave. The larger the vibration value of these vibration sources, the larger the vibration value and noise value of the entire compressor. All the parts that become the vibration source are housed in the gear casing, and the entire gear casing assembly is fixed with a vibration-proof rubber or other vibration-proof material to block the vibration that propagates from various vibration sources to the base and cover. To be done.

Next, regarding the belt tension adjusting mechanism, if the motor base is provided with a hinge mechanism and the fitting clearance of the hinge portion is made small, the motor base is mounted after the first V-belt is centered and attached. Even if the hinge is rotated about the hinge and a new belt tension is applied, the misalignment of the V-belt in the motor axis direction does not occur. In addition, bushes and sleeves made of highly lubricious material are provided at the metal-to-metal contacting parts such as the hinge part of the belt tension adjusting device, due to the propagation of vibration of the motor and the action of impact load when the motor is started and stopped. It is difficult for seizure and wear to occur at the contact area.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 to 3, the main constituent parts are air (gas, etc.) sucked from a suction valve (not shown).
-Stage compressor body 1, which boosts the pressure to a predetermined intermediate pressure, two-stage compressor body 2, which boosts the compressed air boosted by the one-stage compressor body 1 to a predetermined discharge pressure, one-stage compressor body 1 and two-stage compressor A gear casing 3 that fixes the main body 2 and houses the speed increasing device, a motor 4 that is a power source, and a V belt 5 that transmits the axial power from the motor 4 to the compressor main bodies 1 and 2. Further, a common base 6 for arranging all the components and a soundproof cover 7 for blocking noise to the outside are provided.

As shown in FIG. 4, the first-stage compressor body 1 and the second-stage compressor body 2 have a pair of male rotors 8 and female rotors 9 that mesh with each other, and bearings 10, 11 for supporting both rotors 8, 9. 1
2, 13, a male rotor 8, and a pair of timing gears 14, 15 fitted to the discharge side shaft ends of the male rotor 9,
Pinion gear 16 fitted to the suction side shaft end of the female rotor 9
When the shaft power is transmitted to the male rotor 8 and the female rotor 9, the male rotor 8 and the female rotor 9 rotate in a non-contact manner via the timing gears 14 and 15, and the air sucked from the suction port is discharged from the discharge port.

As shown in FIG. 5, inside the gear casing 3, the bull gear 1 for transmitting the shaft power to the pinion gear 16.
7, a gear shaft 18 into which the bull gear 17 is fitted, a bearing 19 that supports the gear shaft 18, and a bearing 20,
A V-pulley 21 is fitted on the shaft end of the gear shaft 18.

On the other hand, as shown in FIGS. 1, 2 and 3, the gear casing 3 is provided with flanges 22 and 23 for fixing the first-stage compressor main body 1 and the second-stage compressor main body 2 on the upper side thereof, and the side faces thereof. A gear casing oil reservoir 24 for storing lubricating oil is provided, and a gear casing side frame 2 for reinforcement is provided on the side opposite to the side surface.
5, and a gear casing bottom frame 26 for reinforcement is provided on the bottom portion.

An M sheave 27 is attached to the shaft end of the motor 4, and the motor 4 is provided below the first-stage compressor body 1 and the second-stage compressor body 2 with a gear casing oil sump 24 and a gear casing side frame 25. And is fixed to the motor base 28.

Further, as shown in FIGS. 1 and 6, four gear casing legs 29 for fixing the gear casing are provided on the bottom surface of the gear casing 3. Insert the anti-vibration rubber 30 between the gear casing foot 29 and the common base 6, and tighten the bolt 3
1, the nut 32 to the gear casing assembly common base 6
Fixed to.

The shaft power from the motor 4 is M sheave 27,
The pinion gear 16 is transmitted to the bull gear 17 via the V-belt 5, V-pulley and 21, and is accelerated to rotate the first-stage compressor body 1 and the second-stage compressor body 2.

The vibration source of the two-stage oil-free screw compressor is pulsating gas torque due to the meshing of the male rotor 8 and the female rotor 9 and the bearings 10, 11, 12, 1 in the compressor bodies 1, 2.
3 internal play, internal play of bearings 19 and 20 in gear casing 3, male rotor 8, female rotor 9, timing gear 1
4,15, union of pinion gear 16, bull gear 1
7, M sheave 27, V pulley 21, motor rotor imbalance, etc. The larger the vibration value of these vibration sources is, the more this vibration is transmitted to the common base 6 and the soundproof cover 7, and the larger the vibration value and the noise value of the entire two-stage compressor unit are.

As in the present invention, all the parts to be the vibration source including the motor are housed in the gear casing, and the entire gear casing assembly is fixed with a vibration-proof rubber or other vibration-proof material. The vibration propagating from the vibration source to the common base and soundproof cover is blocked, and the vibration and noise of the entire two-stage compressor unit can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS. 7 to 9, 10, and 11. In the second embodiment of the present invention, a belt tension adjusting mechanism is added to the first embodiment.

Two gear casing bosses 33 having screw holes are formed at the joint between the gear casing oil sump 24 and the gear casing bottom frame 26, and a screw is formed at the joint between the gear casing side frame 25 and the gear casing bottom frame 26. Two gear casing bosses 34 having holes are provided. Further, two motor base hinge portions 35 are provided at the end of the motor base 28 side.

A hinge bolt 36 is attached to the gear casing boss 33, and a hinge bolt 37 is attached to the gear casing boss 34.
Is screwed in. The motor base hinge portion 35 is fitted to the hinge bolt 36, the support bolt 39 is fitted to the hinge bolt 37, and the support bolt 39 and the motor base 28 are fixed by double nuts 40 and 41. Further, the support bolt 39 and the motor base hinge portion 3
5 is fixed by a double nut 42, and the hinge bolt 37 and the support bolt 39 are fixed by a double nut 43.

Further, as shown in FIGS. 9 to 11, between the motor base hinge portion 35 and the hinge bolt 36,
Further, a cylindrical bush 46 made of metal such as white metal having self-lubricating property is fitted between the support bolt hinge portion 44 and the hinge bolt 37. Further, a sleeve 47 made of a metal having a high fixed lubricity is provided at a contact portion between the gear casing boss 33 and the motor base hinge portion 35.

When a new V belt is attached to the M sheave 27 and the V pulley 21, the motor base 28 is attached to the V pulley 21.
Rotate around hinge bolt 36 in the direction to M sheave 2
7. Shorten the axial distance between the V pulley 21 and the V belt 5, and then tighten the double nuts 40 and 41 so that they are positioned downward, and increase the axial distance between the M sheave 27 and the V pulley 21. Appropriate belt tension is applied to the V-belt 5.

In addition to the above structure, the hinge bolt 3
6 and the bush 46 in the motor base hinge part 35, and the fitting gap between the hinge bolt 37 and the bush 46 in the support bolt hinge part 44, the first V belt 5 is centered. After mounting, the positions of the double nuts 40 and 41 are changed and the motor base 2
Even if 8 is rotated around the hinge bolt 36, the V-belt 5 is not misaligned in the motor axial direction. Therefore, during the maintenance of the compressor, the belt tension adjustment work and the belt replacement work can be easily performed without newly performing the belt centering work, and the work time can be greatly shortened.

When the bush 46 and the sleeve 47 are not used, the motor base hinge portion 35 and the hinge bolt 3
6, and the support bolt hinge portion 44 and the hinge bolt 37,
Also, the gear casing boss portion 33 and the motor base hinge portion 35 are in a metal-to-metal contact state. In this case, seizure and wear (fretting wear) may occur at these contact portions due to the propagation of vibration of the motor and the like, the action of impact load when the motor is started and stopped, and the like.

According to the present invention, a material having high lubricity is used for the metal-to-metal contact portion of the belt tension adjusting mechanism, so that problems such as seizure and abrasion can be prevented.

[0026]

The present invention has the following effects. That is, (1) All the parts that become the vibration source including the motor are housed in the gear casing, and the entire gear casing assembly is fixed with vibration-proof rubber or other vibration-proof material. The vibration propagating to the soundproof cover is blocked, and the vibration and noise of the entire two-stage compressor unit can be reduced.

(2) By adopting the V-belt speed increasing mechanism, the bull gear and the gear casing can be downsized, and the manufacturing cost of the compressor can be reduced.

(3) Since the motor base having the hinge mechanism is provided, the belt tension adjustment work can be performed at the time of compressor maintenance without newly carrying out the belt centering work.
Belt replacement work is possible.

(4) A bush or the like made of a highly lubricious material is provided in the metal contact portion of the belt tension adjusting device,
Problems such as seizure and wear at the contact portion are less likely to occur, and the durability of the components of the belt tension adjusting device is improved.

[Brief description of drawings]

FIG. 1 is a front view seen from a V-belt direction.

FIG. 2 is a side view seen from the direction of the main body of the two-stage compressor.

FIG. 3 is a top view of FIG.

FIG. 4 is a cross-sectional view of a compressor body.

FIG. 5 is a vertical sectional view of a gear casing.

FIG. 6 is a sectional view of the vibration-proof rubber mounting.

FIG. 7 is a front view seen from the V-belt direction.

FIG. 8 is a side view seen from the direction of the main body of the two-stage compressor.

FIG. 9 is a cross-sectional view.

FIG. 10 is an explanatory view of assembly of a support bolt and a bush.

FIG. 11 is an explanatory diagram of assembly of a motor base and a bush.

[Explanation of symbols]

3 ... Gear casing, 4 ... Motor, 5 ... V belt, 6 ...
Common base, 21 ... V pulley, 27 ... M sheave, 28
... motor base, 30 ... anti-vibration rubber.

Claims (1)

[Claims] 1. A two-stage oil-free type which is composed of a low-pressure stage side compressor body, a high-pressure stage side compressor body, a gear casing for driving both of the compressor bodies, a speed-increasing gear, and an electric motor drive device. In the screw compressor, the low pressure stage side compressor main body and the high pressure stage side compressor main body are arranged on the upper part of the gear casing, a lubricating oil reservoir is provided on a side surface of the gear casing, and a frame is provided on the other side surface. And a motor is arranged below both the compressor main bodies and between the lubricating oil sump and the side frame, and the M sheave, V pulley,
A two-stage oil-free screw compressor, which is provided with a V-belt speed-up drive device composed of a motor base.