JP4349254B2 - Screw compressor - Google Patents

Description

  The present invention relates to a screw compressor that takes in gas from outside, compresses it, and discharges it.

  In screw compressors that do not inject lubricating oil or the like into the compression chamber, the clearance of each part has a great influence on the discharge performance of the compressor. There is a variation of 160%, and a large variation occurs in the discharge performance of the compressor.

Therefore, a rotor inspection method has been proposed in which one rotor is braked with a pair of rotors assembled, the other rotor is rotated in the forward and reverse rotation directions, and a minute gap is measured using a rotation angle difference ( For example, see Patent Document 1).
JP-A-11-51813

  However, if the inspection method described in Patent Document 1 is used, the ejection performance can be predicted to some extent. However, since there is no mechanism for adjusting the ejection performance, it is not possible to reduce variations in ejection performance due to individual differences.

  In view of the above points, an object of the present invention is to reduce variation in discharge performance among individual screw compressors.

  In order to achieve the above object, according to the first aspect of the present invention, a housing (7) having a suction port (7a) and a discharge port (7b) and a rotor chamber (10) in the housing (7) are accommodated. And a pair of rotors (1, 2) formed with meshing helical teeth, a suction space (10b) communicating with the suction port (7a) of the rotor chamber (10), and a rotor chamber (10 ) And a discharge space (10c) communicating with the discharge port (7b), and the gas sucked from the suction port (7a) by the rotation of the pair of rotors (1, 2) is compressed from the discharge port (7b). In the screw compressor that discharges, gas is formed from the discharge space (10c) to the suction space (10b), which is formed on a flat portion of the housing (7) facing the high pressure side end surfaces (1b, 2b) of the rotor (1, 2). Groove (7c) and groove Disposed within 7c), characterized in that it comprises a groove (leak adjustment member (51 for adjusting the amount of gas leaking through the 7c)).

  According to this, since the discharge performance can be adjusted by adjusting the gas leakage amount, it is possible to reduce the discharge performance variation among the individual screw compressors.

  According to a second aspect of the present invention, in the screw compressor according to the first aspect, the amount of gas leakage is adjusted by the position of the leakage adjusting member (51) in the groove (7c). A position adjusting member (52) for adjusting the position of the member (51) is provided.

  According to this, compared with the case where a large number of leakage adjusting members are selectively used, the types of parts can be reduced.

  The invention according to claim 3 is characterized in that, in the screw compressor according to claim 1 or 2, the groove (7c) communicates the suction space (10b) and the discharge space (10c).

  According to this, since a large amount of gas can be leaked through the groove, in other words, since the adjustment range of the gas leakage amount can be increased, even when the dispersion performance variation between individuals is large, the dispersion performance variation between individuals Can be reliably reduced.

  According to a fourth aspect of the present invention, in the screw compressor according to any one of the first to third aspects, the pair of rotors (1, 2) have different outer diameters, and the flat portion of the housing (7) Of these, a groove (7c) is formed only in a portion facing the high pressure side end surface (1b) of the large-diameter rotor (1).

  According to this, since the site | part which forms a groove | channel has a wide space and a big groove | channel can be formed, a groove | channel can be made into one and a groove processing man-hour can be reduced.

  The invention according to claim 5 is characterized in that in the screw compressor according to claim 2, the position adjusting member (52) can be operated from the discharge port (7b).

  According to this, after completion of the assembly / initial discharge performance evaluation, the discharge performance can be easily adjusted and the adjustment man-hours can be reduced.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
An embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view of a screw compressor according to an embodiment, FIG. 2 is a perspective view of a rotor of the screw compressor, FIG. 3 is a cross-sectional view taken along line CC in FIG. 1 with the rotor removed, and FIG. 4 is a cross-sectional view taken along the line DD of FIG. 3, FIG. 5A is a front view of the leakage adjusting member of FIG. 4, FIG. 5B is a bottom view of FIG. 5A, and FIG. It is a front view of this position adjustment member. 7 and 8 are schematic views showing the positional relationship between the groove of the housing and the high-pressure side end face of the rotor when viewed from the direction E of FIG.

  As shown in FIG. 1, the screw compressor of this embodiment includes a screw-shaped male rotor 1 and a female rotor 2, a rotation transmission mechanism 3 that rotationally drives the rotors 1 and 2 by the rotational force of a drive source, and a pair of rotors 1. 2 and a casing 4 that houses the rotation transmission mechanism 3, an input shaft 5 that receives the rotational force of the drive source, and the like. In FIG. 1, the pair of rotors 1 and 2 are arranged side by side on the back side and the near side.

  The male rotor 1 and the female rotor 2 are rotationally driven by a rotation transmission mechanism 3 that obtains rotational force from a drive source such as an electric motor 100. In the first embodiment, the male rotor 1 is on the driving side and the female rotor 2 is on the driven side, and rotates about the rotation shafts 1a and 2a, respectively.

  As shown in FIG. 2, the male rotor 1 and the female rotor 2 are formed in a male screw shape in which a spiral protrusion is formed so as to mesh with each other. The tooth tip of the male rotor 1 and the tooth root of the female rotor 2 mesh with each other, and the tooth tip of the male rotor 1 and the tooth tip of the female rotor 2 mesh with each other. The male rotor 1 is a large-diameter rotor and the female rotor 2 is a small-diameter rotor. The outer diameter A of the male rotor 1 is larger than the outer diameter B of the female rotor 2.

  Returning to FIG. 1, the casing 4 includes a lubrication box 6, a rotor housing 7, and a cover 8 in order from the motor 100 side. The lubrication box 6, the rotor housing 7 and the cover 8 are firmly connected by fastening means such as bolts (not shown). The rotors 1 and 2 and the rotation transmission mechanism 3 are housed in the casing 4 in a state of being separated from each other, the pair of rotors 1 and 2 are housed in the rotor housing 7, and the rotation transmission mechanism 3 is housed in the circulation box 6. Has been.

  In the lubrication box 6, a lubricating oil space 9 in which the rotation transmission mechanism 3 and the lubricating oil supplied to the rotation transmission mechanism 3 are accommodated is formed. As the lubricating oil, for example, an oil having a viscosity comparable to that of engine oil can be used. Lubrication is carried out by splashing the lubricating oil in the lubricating oil space 9 on the gears and the like constituting the rotation transmission mechanism 3.

  The lubrication box 6 is provided with an input shaft 5 that receives a rotational force from the motor 100. The lubrication box 6 is provided with a first bearing 11 on the motor 100 side and a second bearing 12 on the lubricating oil space 9 side. The input shaft 5 is connected to the lubrication box 6 via these bearings 11 and 12. It is supported by. In addition, a first oil seal 13 for preventing the lubricating oil from flowing out of the casing 4 is mounted inside the insertion hole into which the input shaft 5 formed in the lubricating box 6 is inserted.

  A rotor chamber 10 in which a pair of rotors 1 and 2 are accommodated is formed in the rotor housing 7. In the rotor housing 7, a suction port 7 a for sucking gas into the rotor chamber 10 and a discharge port 7 b for discharging gas to the outside of the rotor chamber 10 are formed. The suction port 7 a is provided on the cover 8 side of the axial end portion of the rotor housing 7, and the discharge port 7 b is provided on the lubrication box 6 side of the axial end portion of the rotor housing 7.

  Further, a seal structure is formed in which a minute gap is formed between the outer peripheral tips of the rotors 1 and 2 and the inner wall of the rotor chamber 10. A compression chamber 10a for compressing the gas sucked from the suction port 7a is formed between the rotors 1 and 2 and the inner wall of the rotor chamber 10.

  As described above, the rotors 1 and 2 are rotationally driven by the rotation transmission mechanism 3. The rotation transmitting mechanism 3 is configured to transmit the rotation of the input shaft 5 to the male rotor rotating shaft 1a and the female rotor rotating shaft 2a and to rotate the pair of rotors 1 and 2 synchronously. The rotation transmission mechanism 3 is transmitted to the male rotor rotary shaft 1a from the first and second gears 14 and 15 which transmit the rotation of the input shaft 5 driven by the motor 100 to the male rotor rotary shaft 1a. The third and fourth gears 16 and 17 are configured to transmit the rotation to the female rotor rotating shaft 2a. The third and fourth gears 16 and 17 are timing gears for synchronously rotating the pair of rotors 1 and 2.

  One end side of the male rotor rotating shaft 1a and the female rotor rotating shaft 2a is rotatably supported by the rotor housing 7 via the third and fourth bearings 18 and 19, and the other end side is supported via the fifth and sixth bearings 20 and 21. The cover 8 is rotatably supported.

  Further, the lubricating oil supplied to the third and fourth bearings 18 and 19 is prevented from leaking into the rotor chamber 10 in the insertion holes formed in the rotor housing 7 into which the rotor rotation shafts 1a and 2a are inserted. For this purpose, second and third oil seals 22 and 23 are mounted. Further, the grease sealed in the fifth and sixth bearings 20 and 21 is also prevented from leaking into the rotor chamber 10 through the insertion holes formed in the cover 8 into which the rotor rotation shafts 1a and 2a are inserted. The fourth and fifth oil seals 24 and 25 are attached.

  Next, the characteristic part of the screw compressor of this embodiment is demonstrated.

  As shown in FIGS. 3 and 4, a rectangular column-shaped groove 7 c is provided in a flat portion of the housing 7 that faces the high pressure side end surfaces 1 b and 2 b (see FIG. 2) of the rotors 1 and 2. More specifically, a groove 7 c is provided in a flat portion of the housing 7 that faces the high-pressure end surface 1 b of the male rotor 1. The groove 7c is formed as a recess that is slightly recessed from the contact surface with the rotors 1 and 2.

  As shown in FIG. 7, the groove 7 c can communicate with the suction space 10 b that communicates with the suction port 7 a of the rotor chamber 10 and the discharge space 10 c that communicates with the discharge port 7 b of the rotor chamber 10. Yes. The high-pressure side end surface 1b of the male rotor 1 is the end surface on the lubrication box 6 side of the axial end surfaces, in other words, the end surface on the discharge port 7b side.

  As shown in FIG. 3, a cylindrical first positioning hole 7d having a diameter smaller than the short side of the groove 7c is provided at one end of the groove 7c in the housing 7, and at the other end of the groove 7c in the housing 7, A cylindrical second positioning hole 7e having a diameter larger than the diagonal length of the groove 7c is provided. The second positioning hole 7e opens to the discharge port 7b.

  As shown in FIGS. 3 and 4, the groove 7 c has a rectangular columnar leakage adjustment member 51 that adjusts the amount of gas leaking through the groove 7 c, and a columnar position adjustment that adjusts the position of the leakage adjustment member 51. A member 52 is inserted. The leakage adjusting member 51 has the same cross-sectional shape as the groove 7c, and has a size that allows the groove 7c to fit into the gap. Further, as shown in FIG. 5, a female screw 51 a is formed inside the leakage adjusting member 51.

  As shown in FIG. 6, one end of the position adjustment member 52 is provided with a first cylindrical portion 52 a for positioning that is inserted (for example, press-fitted) into the first positioning hole 7 d of the housing 7. A second cylindrical portion 52b for positioning inserted into the second positioning hole 7e of the housing 7 is provided at the end. Further, a male screw 52 c into which the female screw 51 a of the leakage adjusting member 51 is screwed is formed at the intermediate portion of the position adjusting member 52. In order to rotate the position adjusting member 52 from the outside, a hexagonal hole (not shown) is formed on the end surface of the second cylindrical portion 52b.

  As shown in FIGS. 1 and 3, a pipe member 53 to which a hose (not shown) is connected is detachably attached to the housing 7 at a portion of the discharge port 7 b of the housing 7. When the pipe member 53 is attached to the housing 7, the second positioning hole 7 e of the housing 7 is covered with the flange portion of the pipe member 53. Incidentally, the pipe member 53 is attached to the housing 7 after adjusting the discharge performance described later.

  The rotors 1 and 2, the lubrication box 6, the rotor housing 7, the cover 8, and the leakage adjusting member 51 are made of aluminum, and the position adjusting member 52 is made of iron.

  Next, the operation of the screw compressor of this embodiment will be described.

  When the pair of rotors 1 and 2 are synchronously rotated by the rotation transmission mechanism 3, gas is sucked into the compression chamber 10a from the suction port 7a provided on the cover 8 side of the rotor housing 7. At this time, the volume of the compression chamber 10a is reduced while moving from the cover 8 side to the lubricating oil space 9 side with the rotation of the pair of rotors 1 and 2, so that the gas in the compression chamber 10a is gradually pressurized. It moves toward the lubricating oil space 9 while being compressed.

  When the rotation angle of the pair of rotors 1 and 2 reaches a predetermined angle, the compression chamber 10a reaches the discharge port 7b provided on the lubricating oil space 9 side of the rotor housing 7, and the compression that has been sealed until then. Since the chamber 10a is opened at the discharge port 7b, the compressed gas in the compression chamber 10a is discharged from the discharge port 7b.

  Next, adjustment of the discharge performance of the screw compressor will be described in detail with reference to FIGS.

  First, components other than the pipe member 53 are assembled, and then the leakage adjusting member 51 is set at the reference position and the discharge performance is measured. If the discharge performance deviates from the reference value, the amount of gas leaking through the groove 7c is adjusted by rotating the position adjusting member 52 from the discharge port 7b and adjusting the position of the leak adjusting member 51. As a result, the discharge performance is adjusted.

  Here, the principle of adjusting the amount of gas leaking through the groove 7c will be described. FIG. 7 shows a state where leakage has occurred. That is, when the pair of rotors 1 and 2 are at the rotation angle positions shown in the figure, the space in which the leakage adjusting member 51 is not inserted in the groove 7c (hereinafter referred to as the open space in the groove) is the suction space 10b and the discharge space 10c. Therefore, gas leaks from the high pressure discharge space 10c to the low pressure suction space 10b through the open space in the groove.

  On the other hand, FIG. 8 shows a state where no leakage occurs. That is, when the pair of rotors 1 and 2 are at the rotation angle positions shown in the figure, the high-pressure side end surface 1b of the male rotor 1 is in contact with the leakage adjusting member 51 to block communication between the open space in the groove and the discharge space 10c. Therefore, no gas leaks through the open space in the groove.

  Although not shown, when the pair of rotors 1 and 2 further rotate and the high-pressure side end surface 1b of the male rotor 1 blocks the communication between the open space in the groove and the suction space 10b, the open space in the groove is also used. No gas leakage occurs.

  Then, by adjusting the position of the leakage adjusting member 51 by the position adjusting member 52, the time during which leakage occurs due to the open space in the groove communicating with the suction space 10b and the discharge space 10c (that is, a pair of rotors) The rotation angle range of 1 and 2 changes, and the amount of gas leaking through the groove 7c changes.

  As described above, in the present embodiment, since the discharge performance can be adjusted by adjusting the amount of gas leaking through the groove 7c, it is possible to reduce the discharge performance variation among the individual screw compressors. .

  In addition, in the predetermined rotation angle range of the pair of rotors 1 and 2, since the open space in the groove communicates with both the suction space 10b and the discharge space 10c, a large amount of gas can be leaked through the groove 7c. Then, since the adjustment range of the gas leakage amount can be increased, even when the variation in discharge performance among individuals is large, it is possible to reliably reduce the variation in discharge performance between individuals.

  Moreover, although the groove | channel 7c is provided in the site | part which opposes the high voltage | pressure side end surface 1b of the large diameter rotor 1 among the plane parts of the housing 7, since this site | part has a wide space and the big groove | channel 7c can be formed. The number of grooves 7c can be reduced to one, and the number of processing steps for the grooves 7c can be reduced.

  In addition, since the position of the leakage adjustment member 51 can be adjusted by rotating the position adjustment member 52 from the discharge port 7b, the discharge performance adjustment can be easily performed after the assembly / initial discharge performance evaluation is completed. Adjustment man-hours can be reduced.

(Other embodiments)
In the above embodiment, the amount of gas leakage is adjusted by adjusting the position of the leakage adjustment member 51. However, the gas leakage amount is adjusted by selecting and using a leakage adjustment member having a different thickness or length. Also good.

  Moreover, in the said embodiment, although the groove | channel 7c was provided in the site | part facing the high voltage | pressure side end surface 1b of the large diameter rotor 1 among the plane parts of the housing 7, the high voltage side of the small diameter rotor 2 among the plane parts of the housing 7 is provided. A groove 7c may be provided in a portion facing the end surface 2b, and the leakage adjusting member 51 and the position adjusting member 52 may be inserted into the groove 7c.

It is sectional drawing of the screw compressor which concerns on one Embodiment of this invention. It is a perspective view of the rotor of the screw compressor of FIG. It is sectional drawing which follows the CC line | wire of FIG. 1 in the state which removed the rotor. It is sectional drawing which follows the DD line | wire of FIG. (A) is a front view of the leakage adjustment member of FIG. 4, (b) is a bottom view of (a). It is a front view of the position adjustment member of FIG. It is a schematic diagram which shows the positional relationship of the groove | channel of a housing and the high voltage | pressure side end surface of a rotor when it sees from the E direction of FIG. It is a schematic diagram which shows the positional relationship of the groove | channel of a housing and the high voltage | pressure side end surface of a rotor when it sees from the E direction of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Male rotor, 1b ... High pressure side end surface, 2 ... Female rotor, 7 ... Rotor housing, 7a ... Suction port, 7b ... Discharge port, 7c ... Groove, 10 ... Rotor chamber, 10b ... Suction space, 10c ... Discharge space, 51 ... Leak adjustment member.

Claims (5)

A housing (7) having a suction port (7a) and a discharge port (7b);
A pair of rotors (1, 2) housed in a rotor chamber (10) in the housing (7) and formed with helical tooth grooves meshing with each other;
A suction space (10b) communicating with the suction port (7a) in the rotor chamber (10);
A discharge space (10c) communicating with the discharge port (7b) in the rotor chamber (10);
In the screw compressor that compresses the gas sucked from the suction port (7a) by the rotation of the pair of rotors (1, 2) and discharges the gas from the discharge port (7b),
A groove formed in a flat portion of the housing (7) facing the high pressure side end surface (1b, 2b) of the rotor (1, 2) to leak gas from the discharge space (10c) to the suction space (10b). (7c),
A screw compressor, comprising: a leakage adjusting member (51) disposed in the groove (7c) for adjusting the amount of gas leaking through the groove (7c). The amount of gas leakage is adjusted by the position of the leakage adjusting member (51) in the groove (7c),
The screw compressor according to claim 1, further comprising a position adjusting member (52) for adjusting a position of the leak adjusting member (51). The screw compressor according to claim 1 or 2, wherein the groove (7c) communicates the suction space (10b) and the discharge space (10c). The pair of rotors (1, 2) have different outer diameters, and the groove (only in the portion facing the high-pressure end surface (1b) of the large-diameter rotor (1) in the flat portion of the housing (7). The screw compressor according to any one of claims 1 to 3, wherein 7c) is formed. The screw compressor according to claim 2, wherein the position adjusting member (52) is operable from the discharge port (7b).

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