JP5714454B2 - Compression device - Google Patents

Description

  The present invention relates to a compression apparatus.

  In the screw compressor, the suction pressure and the discharge pressure pulsate according to the phase of the screw rotor. The pulsation of the suction pressure and the discharge pressure causes vibration and can be recognized as noise.

  Patent Document 1 describes an invention that reduces pulsation by changing the cross-sectional area of a discharge flow path of a screw compressor in synchronization with a screw rotor. However, the phase at which the discharge pressure of the screw compressor peaks varies depending on the rotational speed and the discharge pressure. For this reason, the invention described in Patent Document 1 can be applied only when the rotational speed and the pressure condition are constant.

  In Patent Document 2, in order to reduce noise leaking to the outside through the suction passage of the liquid-cooled screw compressor, an amount of cooling liquid corresponding to the number of rotations of the screw compressor is supplied to the suction passage. Although the invention for adjusting the silencing action of the coolant is described, the pulsation on the discharge side cannot be suppressed.

JP 7-332267 A JP 2010-164059 A

  In view of the above problems, an object of the present invention is to provide a compression device that can reduce noise regardless of the number of rotations and pressure conditions.

In order to solve the above-described problems, a compression apparatus according to the present invention includes a plurality of screw compressors having the same number of teeth of a male rotor, which are driven so that the number of rotations of the male rotor is equal, and whose discharge passages are connected to each other. has, when the number of the screw compressor n, the number of teeth of the male rotor is m, the plurality of screw compressors, 360 / (m · n) degrees each of the male rotor phase have been shifted The suction flow paths are connected to the same intake chamber so that the suction pressures are equal to each other .

According to this configuration, each screw compressor cancels out the pulsation of the discharge pressure, so the pulsation of the discharge pressure is small and the noise is low.
Further, since the suction pressures are connected to be equal to each other, the conditions on the discharge side are equalized by matching the conditions on the suction side, and the pulsations on the discharge side can be effectively offset.

  In the compression device of the present invention, the plurality of screw compressors may be connected to each other via gears and may be driven by a single motor.

  According to this configuration, since the phase difference between the male rotors of each screw compressor is mechanically determined, pulsation can be reliably reduced.

    As described above, the compression apparatus according to the present invention has a plurality of screw compressors having discharge rotors connected to each other and having the same number of teeth of the male rotor, the number of the screw compressors being n, and the teeth of the male rotor. When the number is m, the phase of the male rotor is shifted by 360 / (m · n) degrees in the plurality of screw compressors. Therefore, according to the present invention, it is possible to provide a compressor with low discharge pressure pulsation and low noise.

It is a schematic sectional drawing of the compression apparatus of 1st Embodiment of this invention. It is a figure which shows the connection of the screw rotor and motor of the compression apparatus of FIG. It is a figure which shows the connection of the screw rotor and motor of the compression apparatus of 2nd Embodiment of this invention.

  Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows a schematic configuration of an air compressor 1 according to the first embodiment of the present invention. The air compressor 1 includes two (number n = 2) screw compressors 2a and 2b, a single motor 3 that drives the screw compressors 2a and 2b, and screw compressors 2a and 2b and a motor 3. A gear box 4 to be connected, an intake chamber 5 having a filter 5a, suction passages 6a and 6b for connecting the intake chamber 5 and the suction portions of the screw compressors 2a and 2b, and a discharge portion of the screw compressors 2a and 2b, respectively. Each of the discharge channels 7a and 7b is connected to each other, and the collecting channel 8 is connected to the discharge channels 7a and 7b.

  Each of the screw compressors 2a and 2b accommodates a male rotor 10 and a female rotor 11 that mesh with each other as shown in FIG. The rotor shaft 10 a of the male rotor 10 extends into the gear box 4, and driven gears 13 a and 13 b that are engaged with and driven by the drive gear 12 attached to the output shaft 3 a of the motor 3 are attached in the gear box 4. It has been.

  In the screw compressors 2a and 2b, the shapes of the male rotor 10 and the female rotor 11 are equal to each other. In the present embodiment, the male rotor 10 is a screw rotor with 4 threads (number of teeth m = 4), and the female rotor 11 is a 6 screw rotor. The number of teeth of the driven gears 13a and 13b is also equal to each other, but the driven gear is set so that the phase of the male rotor 10 is 45 degrees and the phase of the female rotor 11 is 30 degrees different between the screw compressor 2a and the screw compressor 2b. 13a, 13b and the drive gear 12 are engaged.

  In the air compressor 1, the pressure of the compressed air discharged from the screw compressors 2a and 2b changes in the same manner for each tooth gap. Therefore, the pressure of the compressed air discharged from the screw compressors 2 a and 2 b peaks at every 90 degrees in the phase of the male rotor 10. Since the screw compressors 2a and 2b are shifted from each other by 45 degrees in the phase of the male rotor 10, the timing at which the peak pressure of the compressed air discharged from the screw compressors 2a and 2b is generated is relative to the male rotor 10. The timing is shifted by 45 degrees in the phase.

  For this reason, the pulsation of the discharge pressure in the discharge flow path 7a of the screw compressor 2a and the pulsation of the discharge pressure in the discharge flow path 7b of the screw compressor 2b are shifted to cancel each other's peaks. The pulsation of the pressure of the compressed air in the flow path 8 becomes small.

  In the compressor 1 of this embodiment, as a result of measuring the noise value by changing the phase of the male rotor 10 of the screw compressors 2a and 2b and measuring the noise value, the noise value when the phase of the male rotor 10 is shifted by 45 degrees is The value was about half that when the phase of the male rotor 10 was the same.

  In the present embodiment, the suction flow paths 6 a and 6 b are arranged so as to suck in the air in the same intake chamber 5. For this reason, the suction pressure of the screw compressor 2a and the suction pressure of the screw compressor 2b become equal. Therefore, the pressure changes of the compressed air discharged from the screw compressors 2a and 2b having the same shapes of the male rotor 10 and the female rotor 11 have the same waveform with only different phases. Thereby, the pulsations of the discharge pressure of the screw compressors 2a and 2b are canceled out to the same extent.

  Next, FIG. 3 shows a configuration of gears related to driving of the male rotor 10 and the female rotor 11 according to the compression device 1 of the second embodiment of the present invention. The compression apparatus 1 of this embodiment has three (n = 3) screw compressors 2a, 2b, 2c, and the driven gears 13a, 13b, 13c of the male rotor 10 of each screw compressor 2a, 2b, 2c. Are connected to each other via an intermediate gear 14. Only the driven gear 13b of the screw compressor 2b is engaged with and driven by the drive gear 12 driven by one motor (not shown).

  In the present embodiment, in the screw compressors 2a, 2b, 2c, the phase of each male rotor 10 is shifted by 30 degrees and the phase of the female rotor 11 is shifted by 20 degrees in order. As a result, the discharge pressures of the screw compressors 2a, 2b, and 2c show one peak every 30 degrees as the phase of the male rotor 10, and these pressure fluctuations cancel each other.

  The present invention can be applied to a compression apparatus having a larger number of screw compressors. In the compressor, where n is the number of screw compressors connected to the discharge flow path and m is the number of teeth of the male rotor of the screw compressor, the phase of the male rotor of each compressor is 360 / (n · m) degrees. By shifting, the pulsations of the discharge pressures of the screw compressors can cancel each other and noise can be reduced.

  Naturally, when the phase of the male rotor is shifted, the phase of the female rotor having the number of teeth m ′ is also shifted by 360 / (n · m ′) degrees. Further, in order to keep the phase of the male rotor constant, the male rotor must be driven so as to have the same rotational speed. If the phase of the male rotor can be kept constant, each screw compressor may be driven by an individual motor.

DESCRIPTION OF SYMBOLS 1 ... Compressor 2a, 2b, 2c ... Screw compressor 3 ... Motor 4 ... Gear box 6a, 6b ... Suction flow path 7a, 7b ... Discharge flow path 8 ... Collective flow path 10 ... Male rotor 11 ... Female rotor 12 ... Drive Gears 13a, 13b, 13c ... driven gear 14 ... intermediate gear

Claims (2)

A plurality of screw compressors having the same number of teeth of the male rotor, which are driven so that the number of rotations of the male rotor is equal, and the discharge flow paths are connected to each other;
When the number of screw compressors is n and the number of teeth of the male rotor is m,
In the plurality of screw compressors, the phases of the male rotors are shifted by 360 / (m · n) degrees , and the suction flow paths are connected to the same intake chamber so that the suction pressures are equal to each other. A compression device characterized by comprising: The compression device according to claim 1, wherein the plurality of screw compressors are connected to each other via a gear and are driven by a single motor .

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