JPS645100Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oil-cooled screw compressor equipped with a means for discharging lubricating oil from a gear chamber housing a speed increasing gear.

(Prior art) Conventionally, as this type of oil-cooled screw compressor,
The devices shown in FIGS. 4 to 7 are known, and two types of methods are employed to drain lubricating oil from the gear chamber. As shown in FIGS. 4 and 5, the oil-cooled screw compressor that adopts the first of these two methods is partitioned by a partition wall 3a provided with pressure equalization holes 16, and the pressure is equalized with each other. Rotor chamber 4 and gear chamber 7
have. A pair of male and female screw rotors (hereinafter referred to as rotors) 5 and 6 that mesh with each other are rotatably housed in the rotor chamber 4. In addition,
Since the rotor chamber 4 and the rotors 5 and 6 appear redundantly in the drawing, the number of the rotor chamber 4 is written in brackets next to the number of the rotor 5. On the other hand, inside the gear chamber 7, a first gear 9 is attached to a drive shaft 8 which is driven by an outdoor motor (not shown) so as to be able to rotate integrally with the drive shaft 8.
and a second gear 10 mounted coaxially with the rotor 6 so as to be able to rotate integrally therewith are housed in mesh with each other, so as to increase the rotation speed of the drive shaft 8 and transmit it to the rotor 6. It has been formed. After compressing the gas sucked in through a suction port 11 provided on one side of the rotor chamber 4, the gas is discharged from a discharge port 12 provided on the other side to a discharge passage (not shown).

Further, a nozzle 13 is provided in the upper part of the gear chamber 7, which supplies lubricating oil to the first and second gears 9 and 10, and also supplies lubricating oil to the lower part of the gear chamber 7 and the suction port 11 side of the rotor chamber 4. The lubricating oil 15 accumulated in the lower part of the gear chamber 7 is communicated with the lower part through a discharge pipe 14.
is guided into the rotor chamber 4. When the oil level on the suction port 11 side of the rotor chamber 4 rises to a certain extent, the lubricating oil 15 mixes with the suction gas and is sucked into the compression space formed by the two rotors 5 and 6. It is assumed that the surface always remains constant. In this case, the lubricating oil 15 flows due to the difference in oil level height between the gear chamber 7 and the suction port 11 side of the rotor chamber 4, that is, the differential pressure of the lubricating oil in each chamber.

However, in this case, the discharge pipe 14 cannot be made too thick due to the structure of the compressor, and if the resistance inside the pipe increases due to its small diameter, the oil level in the gear chamber 7 will rise, causing the first gear 9 or the It reaches up to 2 gears 10. Therefore, the lubricating oil 15 is not only stirred by the gears and the oil temperature increases, but also the loss of rotational energy of the gears increases, and as a result, the shaft power increases. In particular, when gas is mixed in the oil, the resistance of the discharge pipe 14 increases, causing problems such as almost no oil flowing.

Next, FIGS. 6 and 7 show an oil-cooled screw compressor that adopts another method. The oil-cooled screw compressor shown in FIGS. 4 and 5 has a rotor chamber 5 and a gear chamber 7. Except for the partition wall 3a between them, the other parts are substantially the same, and corresponding parts are given the same numbers.

As shown in FIG. 7, the partition wall 3 of this compressor does not have a hole corresponding to the pressure equalizing hole 16 described above.
This completely isolates the rotor chamber 4 and gear chamber 7.

In this case, the gear chamber 7 has a sealed structure, and the discharge pipe 14
Although the lubricating oil 15 is guided to the suction port 11 side through the nozzle 13, the gas in the space above the oil level of the gear chamber 7 does not enter or exit and its volume is approximately constant.
The same amount of lubricating oil as that supplied from
The oil level in the gear chamber 7 is kept constant.

However, due to independent operation of the oil pump before starting the compressor, an excessive amount of lubricating oil 15 accumulates in the gear chamber 7, and the first gear 9 or the second gear 10 does not absorb the lubricating oil 15.
It can sometimes reach a state of 5. Since the gear chamber 7 before starting the compressor does not have a sealed structure, and in this case, the oil level remains constant even after starting the compressor, the gears stir up the lubricating oil, causing vibrations. This not only causes an increase in noise and a rise in oil temperature, but also causes problems such as overloading the gear drive motor and making it prone to burnout.

(Purpose of the invention) The present invention was devised in view of the above conventional problems, and its purpose is to provide an oil-cooled screw compressor that can maintain an appropriate oil level in the gear chamber. It is in.

(Structure of the invention) In order to achieve the above object, the present invention includes a rotor chamber rotatably housing a pair of male and female rotors, and a gear train that rotationally drives one of the rotors. The gear chamber is equipped with a discharge pipe that communicates the lower part of the gear chamber with the lower part of the rotor chamber on the suction port side and guides the lubricating oil supplied into the gear chamber to the suction port side, and also discharges compressed gas. In an oil-cooled screw compressor configured to discharge oil into a discharge flow path that includes oil recovery and oil separation means, the gear chamber and rotor chamber are partitioned by a partition wall that completely blocks off the gear chamber and the rotor chamber, and the oil recovery means is separated from the rotor chamber immediately after the gas outlet side. A line for returning the separated oil in the oil separating means to the low pressure side is formed so as to lead to the upper part of the gear chamber.

(Example) Next, an example of the present invention will be described with reference to the drawings. 1 and 2 show an oil-cooled screw compressor (hereinafter referred to as a compressor) 1 according to the present invention,
As shown in FIG. 3, an oil collector 21 and an oil separator 22
Together, they form a compressed gas generator.

That is, the compressor 1 passes the gas flowing in from the gas inlet 23 through the oil separator 22 and through the orifice 2.
After being sucked in together with the mixed gas containing lubricating oil via the return flow path 2 equipped with 4 and compressed, the compressed mixed gas is discharged to the discharge flow path 25 equipped with an oil recovery device 21 and an oil separator 22. It's becoming like that.
Then, in the oil collector 21, the liquefied lubricating oil is dropped into the lower part of the container and separated from the gas.
A mixed gas containing lubricating oil in a mist state is sent to the oil separator 22. Furthermore, this oil separator 22
In this case, most of the mixed gas is sent to the gas outlet 26 after removing lubricating oil by a filter (not shown), while a part of the mixed gas is sent to the return flow path 2 together with the removed lubricating oil without passing through the filter. It is formed like this.

Therefore, the compressor 1 shown in FIGS. 1 and 2 will be further explained.

This compressor 1 is substantially the same as the compressor shown in FIGS. 1 and 2 above, except for a part of its gear chamber 7, and corresponding parts are given the same numbers. The explanation will be omitted.

As shown in the figure, the above-mentioned return flow path 2 is communicated with the upper space of the gear chamber 7 of the compressor 1. With this configuration, the high-pressure mixed gas from the oil separator 22 is guided into the gear chamber 7, the pressure inside the gear chamber 7 is increased, and the lubricating oil 15 is forced to the suction port 11 side of the rotor chamber 4. This prevents lubricating oil from accumulating in the gear chamber 7. In addition, the mixed gas of gas and lubricating oil flowing out from the return flow path 2 is returned to the suction port 11 side through the gear chamber 7, and the original role of the suction mixed gas in an oil-cooled compressor is fulfilled. It also performs cooling, sealing of gaps between rotors, and lubrication.

In addition, in the above embodiment, the suction port 1 of the rotor chamber 4
1 is shown with a discharge pipe 14 leading to
The present invention is not limited to this, but has a discharge pipe that leads to the suction port side of the confinement part in the rotor chamber 4 (the tooth groove space of the rotors 5 and 6 that traps the suction gas and is in the compression process). It may be hot.

In addition, although the return flow path 2 was designed to lead the high-pressure mixed gas from the oil separator 22, the same function as described above can be achieved even if the return flow path 2 is led from the discharge gas section (high pressure section) of the compressor 1. It can be made to stand.

For example, a pipe may be provided that branches from the discharge passage 25 between the oil recovery device 21 and the oil separator 22 and reaches the gear chamber 7 via an orifice or via a solenoid valve. All you have to do is activate this and open it only when the machine starts up.

(Effect of the invention) As is clear from the above explanation, according to the invention, the gear chamber and the rotor chamber are separated by a partition wall that completely blocks them, and the high pressure gas in the oil separator is guided to the upper part of the gear chamber. Because of this structure, the gear chamber is under high pressure, and the lubricating oil is forced to return to the low-pressure side of the rotor chamber suction port or to the confinement area, preventing the lubricating oil from accumulating in the gear chamber. can. As a result, the rotor driving section is prevented from being overloaded, the vibration and noise of the compressor are reduced, and the temperature rise in the gear chamber can be suppressed.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the compressor according to the present invention, Figure 2
The figure is a sectional view taken along the - line in Figure 1, and Figure 3 is an equipment configuration diagram of a compressed gas generation device using the compressor in Figure 1.
Figures 4 and 6 are longitudinal sectional views of a conventional compressor, and Figure 5
The figures are a cross-sectional view taken along the line -- in FIG. 4, and FIG. 7 is a cross-sectional view taken along the line -- in FIG. 1... Compressor (oil-cooled screw compressor), 2...
...Return flow path, 3... Partition wall, 4... Rotor chamber, 5,
6... Rotor (screw rotor), 7... Gear room,
9...First gear, 10...Second gear, 11...Suction port, 14...Discharge pipe, 21...Oil recovery device, 22
...Oil separator.

Claims (1)

[Scope of utility model registration request] A rotor chamber that rotatably accommodates a pair of male and female rotors, a gear chamber that accommodates a gear train that rotationally drives one of the rotors, and a lower part of this gear chamber that is located on the suction port side of the rotor chamber. A discharge pipe communicating with the lower part of the gear chamber and guiding the lubricating oil supplied into the gear chamber to the suction port side, and discharging the compressed mixed gas to a discharge flow path including oil recovery and oil separation means. In a refrigerated screw compressor, the gear chamber and the rotor chamber are separated by a partition wall that completely isolates them, and a line for returning the separated oil in the oil separating means to the low pressure side immediately after the gas outlet side of the oil collecting means or in the oil separating means is connected to the gear chamber. An oil-cooled screw compressor characterized by being formed so as to lead to the upper part of the chamber.