Claw compressor

Abstract

Provided is a claw compressor in which a fluid to be compressed is unlikely to leak. In the present invention, an endless first groove part (g1) along a peripheral edge of a male rotor (24) is formed in an end surface (24d) of the male rotor (24) facing an accommodation surface, a tip seal (51) for improving airtightness by contacting a first accommodation surface (9b) is provided in the first groove part (g1), a pressing member is provided between the first groove part (g1) and the tip seal (51) and presses the tip seal (51) toward the accommodation surface, and a string-shaped rubber member (55) elongated along the first groove part (g1) is provided as the pressing member in a first range (g1a) in which the radius of curvature of the first groove part (g1) formed in the male rotor (24) is greater than a prescribed radius of curvature.

Description

Claw compressor

[0001] The present disclosure relates to claw compressors.

[0002] A claw compressor includes a pair of rotors, each with a hook-shaped claw, housed in a housing. The rotors rotate at the same speed in opposite directions without contact while maintaining a predetermined clearance, forming a compression section with the two rotors and the housing. Fluid compressed in the compression section is discharged to the outside of the housing. Such claw compressors are often used primarily as vacuum pumps and blowers (see, for example, Patent Document 1).

[0003] Patent No. 6845596

[0004] When a claw compressor is used to compress steam generated by a steam generation heat pump used as a boiler replacement, the differential pressure between the suction pressure and the discharge pressure is larger than when the claw compressor is used as a vacuum pump or a blower. This tends to result in a large amount of fluid leaking from the gap between the housing and the rotor (e.g., the gap between the surface of the housing perpendicular to the rotor's rotation axis and the end face of the rotor facing that surface). To achieve high efficiency, however, it is necessary to reduce this leakage. However, in claw compressors used as vacuum pumps or blowers, the differential pressure between the suction pressure and the discharge pressure is small, so sufficient measures to prevent fluid leakage have not been taken.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a claw compressor that is less susceptible to leakage of fluid to be compressed.

[0006] In order to solve the above-mentioned problems, the claw compressor of the present disclosure employs the following means: A claw compressor according to one aspect of the present disclosure includes: a first rotor that rotates about a first axis and has two first claws that protrude in a radial direction relative to the first axis; a second rotor that rotates in an opposite direction to the first rotor about a second axis that is parallel to the first axis and has two second claws that protrude in a radial direction relative to the second axis; a housing that forms a compression chamber that accommodates the first rotor and the second rotor; a plurality of seal members; and a plurality of pressing members, wherein the housing forms the compression chamber between a first accommodating surface and a second accommodating surface that are orthogonal to the first axis and the second axis, and the first rotor that faces the first accommodating surface and / or the second accommodating surface is pressed against the housing. and / or an endless seal groove is formed on at least one end face of the second rotor along the periphery of the first rotor and / or the second rotor, the seal groove is provided with the seal member that increases airtightness by coming into contact with the first accommodating surface and / or the second accommodating surface, the pressing member is a member that is provided between the seal groove and the seal member and presses the seal member toward the first accommodating surface and / or the second accommodating surface, and in the range of the seal groove formed in the first rotor and / or the second rotor where the radius of curvature is larger than a predetermined radius of curvature, a first elastic member that is elongated along the seal groove is provided as the pressing member.

[0007] According to the present disclosure, it is possible to provide a claw compressor that is less susceptible to leakage of fluid to be compressed.

[0008] 1 is a perspective view of a claw compressor according to an embodiment of the present disclosure; FIG. 1 is a cross-sectional view taken along line II-II of FIG. 1; FIG. 2 is a cross-sectional view taken along line III-III of FIG. 2; FIG. 3 is a partially enlarged view showing the vicinity of the male rotor of the claw compressor shown in FIG. 2; FIG. 4 is a partially enlarged view showing the vicinity of the female rotor of the claw compressor shown in FIG. 2; FIG. 5 is a view of the male rotor and female rotor shown in FIG. 2 from the gear portion side (without tip seal); FIG. 6 is a view of the male rotor and female rotor shown in FIG. 2 from the discharge port side (without tip seal); FIG. 7 is a view of the male rotor and female rotor shown in FIG. 2 from the gear portion side; FIG. 8 is a cross-sectional view taken along line X-X of FIG. 8; FIG. 10 is a plan view looking down from above (tip seal omitted); FIG. 11 is a cross-sectional view taken along line XII-XII of FIG. 8; FIG. 12 is a plan view looking down from above (tip seal omitted); FIG. 13 is a cross-sectional view of Modification 1 taken along the same cross-section as FIG. 12; FIG. 14 is a view of Modification 2 taken along the gear portion side of the male rotor and female rotor shown in FIG. 2;

[0009] Hereinafter, a claw compressor according to an embodiment of the present disclosure will be described with reference to the drawings.

[0010] In the following description, the up-down direction refers to the direction from top to bottom or bottom to top, the front-to-back direction refers to the direction from front to back or back to front, and the left-to-right direction refers to the direction from left to right or right to left. The up-to-down direction, front-to-back direction, and left-to-right direction are substantially perpendicular to each other. These directions are terms used to facilitate understanding of the description and do not limit the actual position of the product.

[0011] [Basic Structure] The claw compressor 1 is a device that compresses a fluid. The claw compressor 1 is used, for example, to compress steam generated by a steam generating heat pump that is used as a substitute for a boiler.

[0012] 1 and 2, the claw compressor 1 includes a compression section 3 having a compression chamber 20 formed therein, and a gear section 5 accommodating timing gears 39 and 49. The compression section 3 is formed by a front housing 7 and an intermediate housing 9. The gear section 5 is formed by the intermediate housing 9 and a rear housing 11.

[0013] For example, four legs 12 extending downward are provided symmetrically in the front-rear and left-right directions on the lower surface of the intermediate housing 9. The claw compressor 1 is placed on an installation surface by these legs 12.

[0014] An intake port 13 for drawing in steam (fluid) is provided on the upper surface of the intermediate housing 9 that constitutes the compression section 3. The intake port 13 is in communication with the compression chamber 20 and extends, for example, upward. A discharge port 15 for discharging compressed steam is provided on the front housing 7 that constitutes the compression section 3. The discharge port 15 is in communication with the compression chamber 20 and extends, for example, forward. The steam is, for example, water vapor. The drawn steam may be under negative pressure or positive pressure.

[0015] The compression section 3 is configured so that the front housing 7 is attached to the intermediate housing 9 so as to close the front opening of a recess formed in the intermediate housing 9, thereby forming a compression chamber 20 therein. The recess in the intermediate housing 9 is formed by an inner circumferential surface 9a and a first housing surface 9b that closes the rear opening of the inner circumferential surface 9a. An O-ring 22 is installed between the end face of the intermediate housing 9 (the end face that borders the front opening of the recess) and the front housing 7.

[0016] The front housing 7 has a second housing surface 7a that is perpendicular to the first axis X1 and the second axis X2 and faces a recess formed in the intermediate housing 9. The intermediate housing 9 has a first housing surface 9b that is perpendicular to the first axis X1 and the second axis X2 and is one of the surfaces that define the recess. The first housing surface 9b is a surface that is substantially parallel to the second housing surface 7a and is located rearward of the second housing surface 7a. The compression section 3 forms a compression chamber 20 in a region surrounded by the inner circumferential surface 9a of the intermediate housing 9 between the housing surface 9b of the intermediate housing 9 and the housing surface 7a of the front housing 7.

[0017] The compression chamber 20 is provided with a pair of rotors, namely a male rotor (first rotor) 24 and a female rotor (second rotor) 26 .

[0018] As shown in Figure 3, the male rotor 24 has a pair of hook-shaped claws (first claws) 24a. The claws 24a protrude in a radial direction perpendicular to the first axis X1 and are provided symmetrically about the first axis X1. The male rotor 24 rotates counterclockwise (in the direction of arrow A1) in Figure 3.

[0019] The female rotor 26 has a pair of hook-shaped claws (second claws) 26a. The claws 26a protrude in a radial direction perpendicular to the second axis X2 and are provided symmetrically about the second axis X2. The female rotor 26 rotates clockwise (in the direction of arrow A2) in FIG. 3.

[0020] The claws 24a of the male rotor 24 and the claws 26a of the female rotor 26 are adapted to mesh without contacting each other. The male rotor 24 is formed with recesses (first recesses) 24b that receive the claws 26a of the female rotor 26 during the compression stroke. The female rotor 26 is formed with recesses (second recesses) 26b that receive the claws 24a of the male rotor 24 during the compression stroke. The compressed steam is discharged to the outside of the compression chamber 20 from the discharge port 15, which is generally triangular in shape in Figure 3.

[0021] The inner circumferential surface 9a of the intermediate housing 9 has a curved shape formed by partially overlapping two cylinders: one centered on the first axis X1 and the other centered on a second axis X2 spaced apart in the left-right direction from the first axis X1. Note that in Figure 3, the inner circumferential surface 9a also extends in the front-to-rear direction. The tips of the claws 24a, 26a of the rotors 24, 26 run along the inner circumferential surface 9a of the intermediate housing 9 with a predetermined clearance therebetween.

[0022] 2, the male rotor 24 is fastened to the first rotating shaft 32 by a first bolt 31. Specifically, the first bolt 31 is screwed to the first rotating shaft 32 with the axis of the first bolt 31 coinciding with the first axis X1. At this time, the head of the first bolt 31 is housed in a cylindrical recess 24c formed in the front center portion of the male rotor 24.

[0023] A key 35 is provided between the tip of the first rotary shaft 32 and the male rotor 24. The key 35 is fitted into a common key groove formed in the male rotor 24 and the first rotary shaft 32, and prevents relative rotation between the male rotor 24 and the first rotary shaft 32.

[0024] The female rotor 26 is fastened to the second rotating shaft 42 by a second bolt 41. Specifically, the second bolt 41 is screwed to the second rotating shaft 42 with the axis of the second bolt 41 coinciding with the second axis X2. At this time, the head of the second bolt 41 is housed in a cylindrical recess 26c formed in the front center portion of the female rotor 26.

[0025] The second rotation shaft 42 is arranged parallel to the first rotation shaft 32. That is, the first axis X1 and the second axis X2 are parallel to each other. The first axis X1 and the second axis X2 extend in the front-rear direction. That is, the first rotation shaft 32 and the second rotation shaft 42 also extend in the front-rear direction.

[0026] No key such as the key 35 is provided between the female rotor 26 and the second rotary shaft 42. Therefore, before the female rotor 26 is fixed by the second bolt 41, relative rotation between the female rotor 26 and the second rotary shaft 42 is permitted.

[0027] The first rotating shaft 32 supporting the male rotor 24 has its tip located within the compression chamber 20 and its rear end connected to a drive unit (not shown). An example of the drive unit is an electric motor. The first rotating shaft 32 rotates about a first axis X1, thereby rotating the male rotor 24 within the compression chamber 20. The first rotating shaft 32 is rotatably supported by a front bearing 37 and a rear bearing 38.

[0028] The front bearing 37 is provided in the intermediate housing 9. For example, a double-row ball bearing is used as the front bearing 37. However, the front bearing 37 is not limited to a double-row or ball bearing. The rear bearing 38 is located rearward of the front bearing 37 and is provided in the rear housing 11. For example, a single-row ball bearing is used as the rear bearing 38. However, the rear bearing 38 is not limited to a single-row or ball bearing.

[0029] A first timing gear 39 is fixed to the first rotating shaft 32 between the front bearing 37 and the rear bearing 38. The first timing gear 39 is, for example, a spur gear, and rotates together with the first rotating shaft 32 about the first axis X1.

[0030] The first timing gear 39 is provided in the gear portion 5 and is housed in a gear chamber 21 formed by the intermediate housing 9 and the rear housing 11. An O-ring 23 is installed between the end face of the intermediate housing 9 and the rear housing 11.

[0031] A first shaft seal member 71 (two in FIG. 2 ) is provided in the intermediate housing 9 between the front bearing 37 and the compression chamber 20. The first shaft seal member 71 is annular and centered on the first axis X1 and is in close contact with the outer peripheral surface of the first rotating shaft 32. A lip seal is an example of the first shaft seal member 71. A first seal pressing member 72 is provided in the intermediate housing 9 adjacent to the forward-most first shaft seal member 71 (close to the first housing surface 9b) of the two first shaft seal members 71. The first seal pressing member 72 is annular and centered on the first axis X1 and is in contact with the front surface of the first shaft seal member 71. The first seal pressing member 72 is fixed to the intermediate housing 9 and restricts movement of the first shaft seal member 71 along the first axis X1 (forward movement). The front surface of the first seal pressing member 72 is flush with the first housing surface 9b.

[0032] The second rotary shaft 42 supporting the female rotor 26 has a front end located within the compression chamber 20 and a rear end terminated in the rear housing 11 .

[0033] The second rotary shaft 42 rotates about the second axis X2, thereby rotating the female rotor 26 within the compression chamber 20. The second rotary shaft 42 is rotatably supported at two locations, a front bearing 47 and a rear bearing 48.

[0034] The front bearing 47 is provided in the intermediate housing 9. The front bearing 37 is, for example, a double-row ball bearing. However, the front bearing 37 is not limited to a double-row or ball bearing. The rear bearing 48 is located rearward of the front bearing 37 and is provided in the rear housing 11. The rear bearing 38 is, for example, a single-row ball bearing. However, the rear bearing 38 is not limited to a single-row or ball bearing.

[0035] A second timing gear 49 is fixed to the second rotating shaft 42 between the front bearing 47 and the rear bearing 48. The second timing gear 49 is, for example, a spur gear, and rotates together with the second rotating shaft 42 about the second axis X2.

[0036] The second timing gear 49 is provided in the gear unit 5 and housed in the gear chamber 21. The second timing gear 49 meshes with the first timing gear 39, and receives driving force from the first timing gear 39. Therefore, the first rotating shaft 32 serves as a driving shaft, and the second rotating shaft 42 serves as a driven shaft.

[0037] A second shaft seal member 81 (two in FIG. 2 ) is provided in the intermediate housing 9 between the front bearing 47 and the compression chamber 20. The second shaft seal member 81 is annular and centered on the second axis X2 and is in close contact with the outer peripheral surface of the second rotating shaft 42. A lip seal is an example of the second shaft seal member 81. A second seal holder 82 is provided in the intermediate housing 9 adjacent to the front of the two second shaft seal members 81 (close to the first housing surface 9b). The second seal holder member 82 is annular and centered on the second axis X2 and is in contact with the front surface of the second shaft seal member 81. The second seal holder member 82 is fixed to the intermediate housing 9 and restricts movement of the second shaft seal member 81 along the second axis X2 (forward movement). The front surface of the second seal holder member 82 is flush with the first housing surface 9b.

[0038] [Operation of the claw compressor] The first rotary shaft 32 is rotationally driven by a drive unit (not shown), causing the male rotor 24 to rotate within the compression chamber 20. The second rotary shaft 42 is rotated by the second timing gear 49, to which a rotational drive force is transmitted from the first timing gear 39, which rotates together with the first rotary shaft 32, causing the female rotor 26 to rotate within the compression chamber 20.

[0039] As the male rotor 24 and female rotor 26 rotate within the compression chamber 20, steam is drawn into the suction port 13. The male rotor 24 rotates counterclockwise in Figure 3 (in the direction of arrow A1), taking in steam into the compression pockets formed by the claws 24a and moving it downward along the outer periphery (inner circumferential surface 9a) of the compression chamber 20. The female rotor 26 rotates clockwise in Figure 3 (in the direction of arrow A2), taking in steam into the compression pockets formed by the claws 26a and moving it downward along the outer periphery (inner circumferential surface 9a) of the compression chamber 20.

[0040] The compression pocket formed by the male rotor 24 and the compression pocket formed by the female rotor 26 join at the bottom center of the compression chamber 20, and in this combined compression pocket, the claws 24a of the male rotor 24 enter the recesses 26b of the female rotor 26 to compress the steam. The compressed steam is discharged to the outside from the discharge port 15. As shown in Figure 5, an injection port 60 may be provided to supply a fluid (e.g., water) to the compression chamber 20 in order to lower the temperature of the compressed steam.

[0041] [Regarding the sealing structure for the gaps between the rotors and the housing surfaces] The sealing structure is designed to prevent steam from leaking from the gaps between the male rotor 24 and the first housing surface 9 b and the second housing surface 7 a, and the gaps between the female rotor 26 and the first housing surface 9 b and the second housing surface 7 a. The sealing structure includes tip seals (sealing members) 51, 52, and 53, and pressing members for pressing them against the housing surfaces 7 a and 9 b.

[0042] The tip seals 51, 52, and 53 are formed from a highly wear-resistant material (for example, a material containing polyphenylene sulfide (PPS), carbon, etc.).

[0043] 4, 6, and 8, the tip seal 51 is a member that airtightly seals the first axial gap CL1 formed between the first housing surface 9b of the compression section 3 and the rear end surface 24d of the male rotor 24 that faces the first housing surface 9b. The tip seal 51 is installed in a first groove portion (seal groove) g1 formed in the rear end surface 24d.

[0044] 5, 6, and 8, the tip seal 52 is a member that airtightly seals the second axial gap CL2 formed between the first housing surface 9b of the compression section 3 and the rear end surface 26d of the female rotor 26 that faces the first housing surface 9b. The tip seal 52 is installed in a second groove portion (seal groove) g2 formed in the rear end surface 26d.

[0045] 4, 7, and 9, the tip seal 53 is a member that airtightly seals the third axial gap CL3 formed between the second housing surface 7a of the compression section 3 and the front end face 24e of the male rotor 24 that faces the second housing surface 7a. The tip seal 53 is installed in a third groove portion (seal groove) g3 formed in the front end face 24e.

[0046] 5, 7, and 9, no tip seal is provided in the fourth axial gap CL4 formed between the second housing surface 7a of the compression section 3 and the front end surface 26e of the female rotor 26 facing the second housing surface 7a. The reason why no tip seal is provided in the fourth axial gap CL4 is because the discharge port 15 is formed in the second housing surface 7a. If a tip seal were provided in the fourth axial gap CL4, the tip seal would come into contact with the corner of the boundary between the discharge port 15 and the second housing surface 7a and be damaged.

[0047] 6 and 8, the first groove g1 is a groove formed in the rear end surface 24d of the male rotor 24. The first groove g1 is a continuous, endless groove formed along the outer circumferential edge of the male rotor 24, i.e., approximately parallel to the outer circumferential edge of the male rotor 24. The first groove g1 is slightly smaller than the outer circumferential edge of the male rotor 24.

[0048] The first groove portion g1 is divided into two ranges, a first range g1a and a second range g1b. The first range g1a is a range in which the radius of curvature is greater than a predetermined radius of curvature. On the other hand, the second range g1b is a range in which the radius of curvature is equal to or less than the predetermined radius of curvature. The radius of curvature of the first groove portion g1 is determined, for example, by a center line passing through the center of the groove in the width direction.

[0049] The second groove g2 is a groove formed in the rear end surface 26d of the female rotor 26. The second groove g2 is a continuous, endless groove formed along the outer circumferential edge of the female rotor 26, i.e., approximately parallel to the outer circumferential edge of the female rotor 26. The second groove g2 is slightly smaller than the outer circumferential edge of the female rotor 26.

[0050] The second groove portion g2 is divided into two ranges, a first range g2a and a second range g2b. The first range g2a is a range in which the radius of curvature is greater than a predetermined radius of curvature. On the other hand, the second range g2b is a range in which the radius of curvature is equal to or less than the predetermined radius of curvature. The radius of curvature of the second groove portion g2 is determined, for example, by a center line passing through the center of the groove in the width direction.

[0051] 7 and 9, the third groove g3 is a groove formed in the front end surface 24e of the male rotor 24. The third groove g3 is a continuous, endless groove formed along the outer circumferential edge of the male rotor 24, i.e., approximately parallel to the outer circumferential edge of the male rotor 24. The third groove g3 is slightly smaller than the outer circumferential edge of the male rotor 24.

[0052] The third groove portion g3 is divided into two ranges, a first range g3a and a second range g3b. The first range g3a is a range in which the radius of curvature is greater than a predetermined radius of curvature. On the other hand, the second range g3b is a range in which the radius of curvature is equal to or less than the predetermined radius of curvature. The radius of curvature of the third groove portion g3 is determined, for example, by a center line passing through the center of the groove in the width direction.

[0053] Different types of pressing members are installed depending on the range (first range or second range) of the grooves g1, g2, and g3. In other words, different types of pressing members are used depending on the curvature radii of the grooves g1, g2, and g3. The following description will be given taking the first groove g1 and the tip seal 51 installed in the first groove g1 as an example.

[0054] 9 to 13, multiple types of pressing members are provided in the first groove g1 between the tip seal 51 and the bottom surface of the first groove g1. Each pressing member is a member that exhibits elasticity at least in the depth direction of the first groove g1 (the thickness direction of the male rotor 24).

[0055] As shown in Figures 8, 10, and 11, the pressing member provided in the first region g1a having a large radius of curvature is, for example, a string-shaped rubber member 55 serving as an elongated elastic member (first elastic member) extending along the first groove portion g1. The cross-sectional shape of the string-shaped rubber member 55 (the shape of the cross section of the string-shaped rubber member 55 taken along a plane perpendicular to the longitudinal direction) is, for example, a solid circle in an unloaded state. However, it goes without saying that the string-shaped rubber member 55 will deform (be crushed) into, for example, an ellipse upon contact with the tip seal 51. Preferably, the string-shaped rubber member 55 is provided over substantially the entire area of ​​each first region g1a. In other words, it is preferable that one string-shaped rubber member 55 is provided over substantially the entire area of ​​one first region g1a. In this case, the portion of the tip seal 51 corresponding to one first region g1a is pressed by one string-shaped rubber member 55.

[0056] On the other hand, as shown in FIGS. 9 , 12 , and 13 , the pressing member provided in the second region g1b, which has a smaller radius of curvature, is, for example, a coil spring 56 serving as an elastic member (second elastic member) having a smaller dimension along the extension direction of the first groove portion g1 than the first elastic member. The coil spring 56 expands and contracts in the depth direction of the first groove portion g1. The outer shape of the coil spring 56 when viewed from the expansion / contraction direction (see FIG. 13 ) is smaller than the width dimension of the first groove portion g1. It is preferable that multiple coil springs 56 be provided in each second region g1b. In other words, it is preferable that multiple coil springs 56 be provided across substantially the entire area of ​​one second region g1b. In this case, the portion of the tip seal 51 corresponding to one second region g1b is pressed by the multiple coil springs 56.

[0057] The reason for using different pressing members (string-shaped rubber member 55 / coil spring 56) depending on the radius of curvature of the groove g1 is as follows. Specifically, the string-shaped rubber member 55 can efficiently press the tip seal 51 over a wide range along the groove g1. However, in the range with a small radius of curvature, the amount of deformation (curvature) becomes excessively large, resulting in a higher pressing force in the area where the amount of deformation becomes excessively large compared to other areas (ranges). On the other hand, the coil spring 56 has a small dimension along the groove g1 and does not deform along the shape of the groove g1. This makes it less likely that the pressing force will be locally high. However, if coil springs 56 were to be provided over the entire range of the groove g1, a large number of coil springs 56 would have to be evenly provided around the entire circumference of the groove g1, which could lead to concerns about poor assembly and increased costs. Therefore, the advantages of the string-shaped rubber member 55 and the coil spring 56 are utilized by providing the string-shaped rubber member 55 in the range with a large radius of curvature and the coil spring 56 in the range with a small radius of curvature.

[0058] The predetermined radius of curvature is, for example, 45 mm, but this value can be changed as appropriate depending on the shape and dimensions of the male rotor 24, the groove g1, the string-like rubber member 55, and the coil spring 56.

[0059] It is not necessary to provide a pressing member in both the first region g1a and the second region g1b, and for example, either the string-shaped rubber member 55 in the first region g1a or the coil spring 56 in the second region g1b may be omitted. In either case, at least the tip seal 51 can be pressed.

[0060] 12 and 13, the lower portion of the coil spring 56 may be inserted into a hole g1h formed in the bottom surface of the first groove portion g1, thereby stabilizing the installation of the coil spring 56.

[0061] The depth of the first groove portion g1 is substantially constant over the entire circumference, except for the hole g1h.

[0062] Up to this point, the first groove portion g1 and the tip seal 51 have been described as an example, but the second groove portion g2 and the tip seal 52 and the third groove portion g3 and the tip seal 53 also have similar configurations.

[0063] [Effects] The claw compressor 1 according to this embodiment has the following effects.

[0064] In the first ranges g1a, g2a, and g3a where the radius of curvature is greater than a predetermined radius of curvature (e.g., 45 mm), long string-shaped rubber members 55 are provided along the grooves g1, g2, and g3 as pressing members. Therefore, in these ranges, the string-shaped rubber members 55 can press the tip seals 51, 52, and 53 toward the accommodation surfaces 7a and 9b, thereby making it difficult for the compressed fluid to leak. Furthermore, if the string-shaped rubber members 55 are provided along the entire circumference of the grooves g1, g2, and g3, the string-shaped rubber members 55, which deform along the shapes of the grooves g1, g2, and g3, will deform excessively in ranges with small radius of curvature (e.g., second ranges g1b, g2b, and g3b where the radius of curvature is 45 mm or less), and the pressing force in the excessively deformed portions will be higher than in other portions (ranges). In this case, the surface pressure of the tip seals 51, 52, and 53 against the storage surfaces 7a and 9b may become locally high in those areas, possibly exceeding the limit PV value set for the tip seals 51, 52, and 53. Therefore, by limiting the range in which the string-shaped rubber member 55 is provided to a range with a large radius of curvature (for example, first ranges g1a, g2a, and g3a with a radius of curvature greater than 45 mm), the surface pressure of the tip seals 51, 52, and 53 is kept within an appropriate range so as not to exceed the limit PV value, and the tip seals 51, 52, and 53 are efficiently pressed over a wide range along the groove portions g1, g2, and g3.

[0065] Furthermore, in the second ranges g1b, g2b, and g3b where the curvature radius is equal to or less than a predetermined curvature radius (e.g., 45 mm), a coil spring 56 is provided as a pressing member. In these ranges, the coil spring 56 can press the tip seals 51, 52, and 53 toward the accommodation surfaces 7a and 9b, thereby reducing leakage of the compressed fluid. In this case, the dimension of the coil spring 56 along the grooves g1, g2, and g3 is smaller than the corresponding dimension of the string-shaped rubber member 55. In this case, even in the second ranges g1b, g2b, and g3b where the curvature radius is equal to or less than 45 mm, the coil spring 56 does not deform along the shape of the grooves g1, g2, and g3, so the problem of locally high pressing force, as with the string-shaped rubber member 55, is less likely to occur. In other words, even in the second ranges g1b, g2b, and g3b where the curvature radius is equal to or less than a predetermined curvature radius (e.g., 45 mm), the limit PV value can be prevented from being exceeded. However, if coil springs 56 were to be provided in the entire range of grooves g1, g2, and g3, a large number of coil springs 56 would have to be provided evenly around the entire circumference of grooves g1, g2, and g3, which could lead to concerns about poor assembly and increased costs. Therefore, by providing long string-shaped rubber members 55 in the first ranges g1a, g2a, and g3a, which have a large radius of curvature, the above concerns are resolved.

[0066] Furthermore, since the seal pressing members 72, 82 are configured to be flush with the first housing surface 9b, the contact area between the tip seals 51, 52 and the opposing seals can be ensured even when the tip seals 51, 52 pass through the seal pressing members 72, 82. This makes it less likely for the fluid to be compressed to leak.

[0067] 14 , a plate 57 having a larger Young's modulus than the tip seal 51 is provided between the tip seal 51 and the coil spring 56 in the second region g1b of the first groove g1. The plate 57 has a larger dimension along the extension direction of the first groove g1 than the coil spring 56, and a dimension along the width direction of the first groove g1 that is equal to or larger than the coil spring 56. This allows a wider region (the region of the tip seal 51) to be pressed with a uniform force than when the coil spring 56 directly presses the tip seal 51. This prevents the tip seal 51 from contacting one side of the shaft.

[0068] 15 , for example, if an imaginary circle corresponding to the maximum outer diameter of the male rotor 24 is defined as the maximum outer diameter circle C1, and an imaginary circle 15% smaller in diameter than the maximum outer diameter circle C1 is defined as the inner circle C2, the coil spring 56 is preferably provided in the first groove g1 (second range g1b) ranging from the maximum outer diameter circle C1 to the inner circle C2. This allows the coil spring 56 to efficiently press the tip seal 51 located at the tip end of the claw portion 24a. The same applies to the second groove g2 and the third groove g3 of the female rotor 26.

[0069] [Variation 3] As shown in Fig. 16, a string-shaped rubber member 55 having a hollow circular cross section may be used as the first elastic member. The cross section of the string-shaped rubber member 55 may also have a different shape, such as an X-shape. By selecting an appropriate cross section shape, the elasticity exerted can be adjusted.

[0070] [Variation 4] The second elastic member may be a member / component other than the coil spring 56. For example, the other second elastic member may be a leaf spring or a columnar rubber member. Furthermore, any member whose outer shape when viewed in the extension / contraction direction is smaller than the width dimension of the grooves g1, g2, and g3 can be used as the second elastic member.

[0071] [Additional Notes] The claw compressor according to the present embodiment described above can be understood, for example, as follows.

[0072] A claw compressor (1) according to a first aspect of the present disclosure includes: a first rotor (24) that rotates about a first axis (X1) and has two first claw portions (24a) that protrude in a radial direction relative to the first axis; a second rotor (26) that rotates in a direction opposite to that of the first rotor about a second axis (X2) that is parallel to the first axis and has two second claw portions (26a) that protrude in a radial direction relative to the second axis; a housing (7, 9) that forms a compression chamber (20) that houses the first rotor and the second rotor; a plurality of sealing members (51, 52, 53); and a plurality of pressing members (55, 56). The housing forms the compression chamber between a first housing surface (9b) and a second housing surface (7a) that are orthogonal to the first axis and the second axis, and the first housing surface and the second housing surface are pressed against each other. and / or the second rotor, an endless seal groove (g1, g2, g3) is formed along the periphery of the first rotor and / or the second rotor on at least one end face of the first rotor and / or the second rotor facing the first accommodating surface and / or the second accommodating surface, the seal groove is provided with the seal member that increases airtightness by coming into contact with the first accommodating surface and / or the second accommodating surface, the pressing member is a member that is provided between the seal groove and the seal member and presses the seal member toward the first accommodating surface and / or the second accommodating surface, and in a range of the seal groove formed in the first rotor and / or the second rotor where the radius of curvature is larger than a predetermined radius of curvature, a first elastic member (55) that is elongated along the seal groove is provided as the pressing member.

[0073] In the seal groove formed in the rotor, a first elastic member (e.g., a string-shaped rubber member) is provided as a pressing member along the seal groove in a region where the radius of curvature is greater than a predetermined radius of curvature. In this region, the first elastic member presses the seal member toward the first and / or second housing surfaces, thereby reducing leakage of the compressed fluid. Furthermore, if the string-shaped rubber member is provided around the entire circumference of the seal groove, the rubber member, which deforms to conform to the shape of the seal groove, will deform excessively in regions with small radii of curvature (e.g., regions where the radius of curvature is equal to or smaller than the predetermined radius of curvature), resulting in a higher pressing force in the excessively deformed region than in other regions (regions). In this case, the surface pressure of the seal member against the first and / or second housing surfaces will be locally high in these regions, potentially exceeding the limit PV value set for the seal member. Therefore, by limiting the range in which the first elastic member is provided to a range in which the radius of curvature is large (for example, a range in which the radius of curvature is larger than a predetermined radius of curvature), the surface pressure of the sealing member can be kept within an appropriate range and prevented from exceeding the limit PV value, while efficiently pressing the sealing member over a wide range along the sealing groove.

[0074] In the claw compressor according to the second aspect of the present disclosure, in the first aspect, a second elastic member (56) having a dimension along the seal groove smaller than that of the first elastic member is provided as the pressing member in the range where the radius of curvature of the seal groove formed in the first rotor and / or the second rotor is equal to or less than a predetermined radius of curvature.

[0075] In the seal groove formed in the rotor, a second elastic member is provided as a pressing member in a range where the radius of curvature is equal to or less than a predetermined radius of curvature. In this range, the second elastic member can press the seal member toward the first and / or second housing surfaces, thereby reducing leakage of the compressed fluid. In this case, the second elastic member can be a member whose dimension along the seal groove is smaller than that of the first elastic member. For example, the second elastic member can be an elastic member (e.g., a coil spring or a columnar rubber member) whose outer shape is smaller than the width of the seal groove. In this case, even when the radius of curvature is equal to or less than the predetermined radius of curvature, the second elastic member does not deform along the shape of the seal groove, thereby reducing the problem of locally high pressing force, as occurs with string-shaped rubber members. In other words, even when the radius of curvature is equal to or less than the predetermined radius of curvature, the limit PV value can be prevented from being exceeded. However, if the second elastic member were to be provided throughout the entire seal groove, multiple second elastic members would have to be evenly distributed around the entire circumference of the seal groove, which could lead to poor assembly and increased costs. Therefore, the above concerns are resolved by providing a long string-like rubber member in the area with a large radius of curvature.

[0076] In the claw compressor according to the third aspect of the present disclosure, in the second aspect, the second elastic member is provided in the seal groove formed in the first rotor and / or the second rotor in a range from the maximum outer diameter circle (C1) of the first rotor and / or the second rotor to a circle (C2) that is 15% smaller than the maximum outer diameter circle.

[0077] The second elastic member is provided in the seal groove formed in the rotor in a range from the maximum outer diameter circle of the rotor to a circle that is 15% smaller than that maximum outer diameter circle, so that the second elastic member can efficiently press the seal member located at the tip portion of the claw portion.

[0078] In the claw compressor according to the fourth aspect of the present disclosure, in the second or third aspect, an intervening member (57) having a larger Young's modulus than the sealing member and a larger contact area with the sealing member than the second elastic member is provided between the second elastic member and the sealing member.

[0079] An intervening member having a larger Young's modulus than the seal member and a larger contact area with the seal member than the second elastic member is provided between the second elastic member and the seal member, so that a wider area (the area of ​​the seal member) can be pressed with a uniform force than when the second elastic member directly presses the seal member, thereby preventing the seal member from contacting unevenly.

[0080] A claw compressor according to a fifth aspect of the present disclosure is the claw compressor of any one of the first to fourth aspects, wherein the predetermined radius of curvature is 45 mm.

[0081] The predetermined radius of curvature is set to 45 mm, so that it is easy to determine whether to use the first elastic member or the second elastic member.

[0082] A claw compressor according to a sixth aspect of the present disclosure is, in any of the first to fifth aspects, a first rotating shaft (32) extending along the first axis and connected to the first rotor, a second rotating shaft (42) extending along the second axis and connected to the second rotor, a first shaft seal member (71) in close contact with an outer circumferential surface of the first rotating shaft, a second shaft seal member (81) in close contact with an outer circumferential surface of the second rotating shaft, a first seal presser member (72) provided at a position closer to the second accommodating surface than the first shaft seal member and restricting movement of the first shaft seal member along the first axis, and a second seal presser member (82) provided at a position closer to the second accommodating surface than the second shaft seal member and restricting movement of the second shaft seal member along the second axis, wherein the first seal presser member and the second seal presser member are configured to be flush with the first accommodating surface.

[0083] The seal pressing member is configured to be flush with the first housing surface, so that even when the seal member passes through the seal pressing member, the contact area between the seal member and the mating member can be secured, thereby making it less likely for the compressed fluid to leak.

[0084] DESCRIPTION OF SYMBOLS 1 Claw compressor 3 Compression section 5 Gear section 7 Front housing (housing) 7a Second housing surface 9 Middle housing (housing) 9a Inner peripheral surface 9b First housing surface 11 Rear housing (housing) 13 Intake port 15 Discharge port 20 Compression chamber 21 Gear chamber 24 Male rotor (first rotor) 24a Claw portion 24b Recessed portion 24c Recessed portion 24d Rear end surface (end surface) 24e Front end surface (end surface) 26 Female rotor (second rotor) 26a Claw portion 26b Recessed portion 26c Recessed portion 26d Rear end surface (end surface) 26e Front end surface (end surface) 32 First rotating shaft (drive shaft) 42 Second rotating shaft (driven shaft) 51, 52, 53 Tip seal (sealing member) 55 String-shaped rubber member (first elastic member) 56 Coil spring (second elastic member) 57 Plate (intervening member) 60 Injection port 71 First shaft seal member 72 First seal retainer member 81 Second shaft seal member 82 Second seal retainer member C1 Maximum outer diameter circle C2 Inner circle CL1 First axial gap CL2 Second axial gap CL3 Third axial gap CL4 Fourth axial gap g1 First groove portion (seal groove) g1a First range (range with large curvature radius) g1b Second range (range with small curvature radius) g1h Hole g2 Second groove portion (seal groove) g2a First range (range with large curvature radius) g2b Second range (range with small curvature radius) g3 Third groove portion (seal groove) g3a First range (range with large curvature radius) g3b Second range (range with small radius of curvature) X1 First axis X2 Second axis

Claims

1. A compressor comprising: a first rotor that rotates about a first axis and has two first claws that protrude in a radial direction relative to the first axis; a second rotor that rotates in the opposite direction to the first rotor about a second axis that is parallel to the first axis and has two second claws that protrude in a radial direction relative to the second axis; a housing that forms a compression chamber that accommodates the first rotor and the second rotor; a plurality of seal members; and a plurality of pressing members, wherein the housing forms the compression chamber between a first accommodating surface and a second accommodating surface that are perpendicular to the first axis and the second axis, and an endless seal groove is formed along the periphery of the first rotor and / or the second rotor on at least one end face of the first rotor and / or the second rotor that faces the first accommodating surface and / or the second accommodating surface, and the seal member that comes into contact with the first accommodating surface and / or the second accommodating surface is provided in the seal groove to enhance airtightness, the pressing member is a member that is provided between the seal groove and the seal member and presses the seal member toward the first accommodating surface and / or the second accommodating surface, and a first elastic member that is elongated along the seal groove is provided as the pressing member in a range of the seal groove formed in the first rotor and / or the second rotor where the radius of curvature is larger than a predetermined radius of curvature.

2. A claw compressor as described in claim 1, wherein a second elastic member having a dimension along the seal groove smaller than that of the first elastic member is provided as the pressing member in the seal groove formed in the first rotor and / or the second rotor within a range in which the radius of curvature is equal to or less than the predetermined radius of curvature.

3. A claw compressor as set forth in claim 2, wherein the second elastic member is provided in the seal groove formed in the first rotor and / or the second rotor in a range from the maximum outer diameter circle of the first rotor and / or the second rotor to a circle that is 15% smaller than the maximum outer diameter circle.

4. A claw compressor as described in claim 2, wherein an intervening member having a larger Young's modulus than the sealing member and a larger contact area with the sealing member than the second elastic member is provided between the second elastic member and the sealing member.

5. A claw compressor according to any one of claims 1 to 4, wherein the predetermined radius of curvature is 45 mm.

6. A claw compressor according to any one of claims 1 to 4, comprising: a first rotating shaft extending along the first axis and connected to the first rotor; a second rotating shaft extending along the second axis and connected to the second rotor; a first shaft seal member in close contact with the outer circumferential surface of the first rotating shaft; a second shaft seal member in close contact with the outer circumferential surface of the second rotating shaft; a first seal presser member provided at a position closer to the second accommodating surface than the first shaft seal member, and restricting movement of the first shaft seal member along the first axis; and a second seal presser member provided at a position closer to the second accommodating surface than the second shaft seal member, and restricting movement of the second shaft seal member along the second axis, wherein the first seal presser member and the second seal presser member are configured to be flush with the first accommodating surface.

Images