Technical Field
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The present disclosure relates to a claw compressor and a method for assembling the same.
Background Art
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The claw compressor includes a pair of rotors having hook-shaped claw parts inside a housing that forms a compression chamber. Each rotor rotates at the same speed in opposite directions without contact while maintaining a predetermined clearance, and the two rotors form a compression pocket and discharge a fluid compressed in the compression pocket. Such a claw-type compressor is mainly used as a vacuum pump or a blower (for example, see PTL 1).
Citation List
Patent Literature
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[PTL 1]
Japanese Patent No. 6845596 Summary of Invention
Technical Problem
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In a case where a vapor-generating heat pump is used as an alternative to a boiler and generated vapor is compressed, a differential pressure between a suction pressure and a discharge pressure is large and leakage is large as compared with the vacuum pump or the blower. Therefore, in order to increase efficiency, it is necessary to reduce a clearance during a compression step. In a case where the claw compressor is used for a vapor compression application in this manner, the following problems occur as compared with a vacuum pump application or a blower application.
- (1) A work load of the rotor is large and a torque is large. Therefore, there is a risk that the rotor may be displaced with respect to a shaft during an operation. In particular, a torque on a side of a male rotor is large.
- (2) In order to maintain high efficiency, room capable of adjusting a rotor phase is needed.
- (3) In a case of a form in which power is transmitted from a driving shaft to a driven shaft using a timing gear, the rotors may come into contact with each other due to backlash of the timing gear. Meanwhile, in order to maintain compression efficiency, a clearance between the rotors needs to be set to a minimum value.
- (4) In an oil-free claw compressor, in order to improve compressor efficiency, it is necessary to manage and adjust a clearance of a compression part, but relying solely on component accuracy for managing would mean managing the clearance through stacked tolerances, and there is a problem in that the clearance cannot be reduced.
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The present disclosure is made in view of the above-described circumstances, and an object of the present disclosure is to provide a claw compressor and a method for assembling the same which can achieve high compression efficiency even in a vapor compression application.
Solution to Problem
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A claw compressor according to an aspect of the present disclosure includes a first rotor provided with a claw part protruding in a radial direction, a first rotating shaft that rotatably supports the first rotor, a first bolt fastening part that fastens the first rotor to a shaft end of the first rotating shaft by means of a bolt, a second rotor that rotates in a direction opposite to the first rotor and has a recessed part that receives the claw part during a compression step, a second rotating shaft that rotatably supports the second rotor, a second bolt fastening part that fastens the second rotor to a shaft end of the second rotating shaft by means of a bolt, and a compression chamber that accommodates the first rotor and the second rotor, in which a rotation prevention part that prevents relative rotation between the first rotor and the first rotating shaft is provided.
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A claw compressor according to an aspect of the present disclosure includes a first rotor provided with a claw part protruding in a radial direction, a first rotating shaft that rotatably supports the first rotor, a first bolt fastening part that fastens the first rotor to a shaft end of the first rotating shaft by means of a bolt, a second rotor that rotates in a direction opposite to the first rotor and has a recessed part that receives the claw part, a second rotating shaft that rotatably supports the second rotor, a second bolt fastening part that fastens the second rotor to a shaft end of the second rotating shaft by means of a bolt, and a compression chamber that accommodates the first rotor and the second rotor, in which first hole parts into which a positioning pin is insertable are formed in the first rotor, and second hole parts into which a positioning pin is insertable are formed in the second rotor.
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A method for assembling a claw compressor according to an aspect of the present disclosure is a method for manufacturing a claw compressor including a first rotor provided with a claw part protruding in a radial direction, a first rotating shaft that rotatably supports the first rotor, a first bolt fastening part that fastens the first rotor to a shaft end of the first rotating shaft by means of a bolt, a second rotor that rotates in a direction opposite to the first rotor and has a recessed part that receives the claw part, a second rotating shaft that rotatably supports the second rotor, a second bolt fastening part that fastens the second rotor to a shaft end of the second rotating shaft by means of a bolt, and a compression chamber that accommodates the first rotor and the second rotor, the method including: an insertion step of inserting a positioning pin into first hole parts formed in the first rotor and inserting a positioning pin into second hole parts formed in the second rotor; and a fastening step of fastening each of the bolts of the first bolt fastening part and the second bolt fastening part.
Advantageous Effects of Invention
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High compression efficiency can be achieved even in the vapor compression application.
Brief Description of Drawings
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- FIG. 1 is a perspective view showing a claw compressor according to a first embodiment of the present disclosure.
- FIG. 2 is a cross-sectional view taken along cutting line II-II of the claw compressor of FIG. 1.
- FIG. 3 is a cross-sectional view taken along cutting line III-III of FIG. 2.
- FIG. 4 shows the claw compressor according to a second embodiment of the present disclosure, and is a cross-sectional view corresponding to FIG. 3.
- FIG. 5 shows the claw compressor of FIG. 4 and is a vertical cross-sectional view corresponding to FIG. 2.
- FIG. 6 is a cross-sectional view showing a state in which positioning pins are inserted into the claw compressor of FIG. 5.
- FIG. 7 is a side view showing a jig.
- FIG. 8 is a front view showing a female rotor of the claw compressor according to the second embodiment of the present disclosure.
- FIG. 9 is an enlarged view of a portion B in FIG. 8.
- FIG. 10 shows a claw compressor according to a fourth embodiment of the present disclosure, and is a cross-sectional view corresponding to FIG. 3.
Description of Embodiments
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Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings.
[First Embodiment]
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Hereinafter, a first embodiment of the present disclosure will be described.
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As shown in FIG. 1, a claw compressor 1 includes a compression part 3 in which a compression chamber is formed, and a gear part 5 in which a timing gear is accommodated. The compression part 3 is formed by a first housing 7 and a second housing 9, and the gear part 5 is formed by the second housing 9 and a third housing 11. The claw compressor 1 is erected on an installation surface by, for example, four leg parts 12.
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The compression part 3 includes a suction port 13 that suctions vapor (fluid), and a discharge port 15 that discharges the vapor after compression. The vapor is, for example, water vapor. The vapor to be suctioned may be negative pressure or positive pressure.
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As shown in FIG. 2, the compression part 3 is configured such that the first housing 7 closes a recess formed at a front end (one end) of the second housing 9 and a compression chamber 20 is formed inside. The first housing 7 is airtightly attached to the second housing 9 via an O-ring 22.
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A pair of rotors, that is, a male rotor (first rotor) 24 and a female rotor (second rotor) 26, are provided in the compression chamber 20.
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As shown in FIG. 3, the male rotor 24 has a pair of hook-shaped claw parts 24a. The claw parts 24a are symmetrically provided about a first rotational axis O1. The male rotor 24 rotates counterclockwise (in a direction of an arrow A1) in FIG. 3.
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The female rotor 26 has a pair of hook-shaped claw parts 26a. The claw parts 26a are symmetrically provided about a second rotational axis O2. The female rotor 26 rotates clockwise (in a direction of an arrow A2) in FIG. 3.
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The claw parts 24a of the male rotor 24 and the claw parts 26a of the female rotor 26 mesh with each other in a non-contact manner. A recessed part 26b that receives the claw part 24a of the male rotor 24 during the compression step is formed in the female rotor 26. The compressed vapor is discharged from the discharge port 15 having a substantially triangular shape in FIG. 3.
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As shown in FIG. 3, the compression chamber 20 has a shape defined by an inner wall 9a of the second housing 9, and has a cross-sectional shape in which two circles, that is, a circle centered on the first rotational axis O1 and a circle centered on the second rotational axis O2, partially overlap each other. Tips of the claw parts 24a and 26a of the respective rotors 24 and 26 move along the inner wall 9a of the second housing 9 with a predetermined clearance.
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As shown in FIG. 2, the male rotor 24 is fastened to the first rotating shaft 32 by a first bolt 31. Specifically, as shown in FIG. 2, the first bolt 31 is screwed to the first rotating shaft 32 in a state where an axis of the first bolt 31 is aligned with the first rotational axis O1. A fastening structure (first bolt fastening part) is configured in a state where a central part of the male rotor 24 is interposed between the tip surface of the first rotating shaft 32 and a head of the first bolt 31. The head of the first bolt 31 is accommodated in a cylindrical recess 24c formed at the center of the male rotor 24.
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A key 35 (rotation prevention part) is provided between the male rotor 24 and a tip part of the first rotating shaft 32. The key 35 is fitted to a key groove formed in the male rotor 24 and the first rotating shaft 32 and prevents the male rotor 24 and the first rotating shaft 32 from rotating relative to each other.
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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 in a state where an axis of the second bolt 41 is aligned with the second rotational axis O2. The second rotating shaft 42 is provided in parallel to the first rotating shaft 32. That is, the first rotational axis O1 and the second rotational axis O2 are parallel to each other.
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A fastening structure (second bolt fastening part) is configured in a state where a central part of the female rotor 26 is interposed between the tip surface of the second rotating shaft 42 and a head of the second bolt 41. The head of the second bolt 41 is accommodated in a cylindrical recess 26c formed at the center of the female rotor 26. The key 35 provided between the male rotor 24 and the first rotating shaft 32 is not provided between the female rotor 26 and the second rotating shaft 42. Therefore, before the female rotor 26 is fixed by the second bolt 41, the relative rotation between the female rotor 26 and the second rotating shaft 42 is allowed.
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The first rotating shaft 32 that supports the male rotor 24 has a tip located in the compression chamber 20, and a rear end connected to a drive part (not shown). As the drive part, for example, an electric motor is used. The first rotating shaft 32 rotates about the first rotational axis O1, and thus the male rotor 24 rotates in the compression chamber 20. The first rotating shaft 32 is rotatably supported at two locations of a tip-end-side bearing 37 and a rear-end-side bearing 38. The tip-end-side bearing 37 is provided in the second housing 9 and, for example, a double-row ball bearing is used. However, the tip-end-side bearing 37 is not limited to a double row or a ball bearing. The rear-end-side bearing 38 is located closer to a rear end side than the tip-end-side bearing 37 and is provided in the third housing 11. The rear-end-side bearing 38 is a single-row ball bearing, but is not limited to a single row or a ball bearing.
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A first timing gear 39 is fixed to the first rotating shaft 32 between a tip-end-side bearing 37 and the rear-end-side bearing 38. The first timing gear 39 is, for example, a spur gear and rotates about the first rotational axis O1 together with the first rotating shaft 32.
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The first timing gear 39 is provided in the gear part 5 and is accommodated in a gear chamber 21 formed between a rear end (other end) of the second housing 9 and a front end of the third housing 11. The second housing 9 and the third housing 11 are attached to each other in a liquid-tight manner via an O-ring 23 to seal the lubricating oil in the gear chamber 21.
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The second rotating shaft 42 that supports the female rotor 26 has a tip located in the compression chamber 20, and a rear end terminated in the third housing 11. A rear end cover 44 is provided in the third housing 11 and closes the rear end of the second rotating shaft 42. The rear end cover 44 is fixed to the third housing 11 in a liquid-tight manner via an O-ring 45 to seal the lubricating oil in the gear chamber 21.
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The second rotating shaft 42 rotates about the second rotational axis O2, and thus the female rotor 26 rotates in the compression chamber 20. The second rotating shaft 42 is rotatably supported at two locations of the tip-end-side bearing 47 and a rear-end-side bearing 48. The tip-end-side bearing 47 is provided in the second housing 9 and, for example, a double-row ball bearing is used. However, the tip-end-side bearing 47 is not limited to a double row or a ball bearing. The rear-end-side bearing 48 is located closer to a rear end side than the tip-end-side bearing 47 and is provided in the third housing 11. The rear-end-side bearing 48 is a single-row ball bearing, but is not limited to a single row or a ball bearing.
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A second timing gear 49 is fixed to the second rotating shaft 42 between the tip-end-side bearing 47 and the rear-end-side bearing 48. The second timing gear 49 is, for example, a spur gear and rotates about the second rotational axis O2 together with the second rotating shaft 42.
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The second timing gear 49 is provided in the gear part 5 and is accommodated in the gear chamber 21. The second timing gear 49 meshes with the first timing gear 39, and a driving force is transmitted from the first timing gear 39. Therefore, the first rotating shaft 32 is a driving shaft, and the second rotating shaft 42 is a driven shaft.
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The claw compressor 1 having the above-described configuration operates as follows.
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The first rotating shaft 32 is rotationally driven by the drive part (not shown), and the male rotor 24 rotates in the compression chamber 20. The second rotating shaft 42 is rotated by the second timing gear 49 to which a rotational driving force is transmitted from the first timing gear 39 that rotates together with the first rotating shaft 32, and the female rotor 26 rotates in the compression chamber 20.
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The male rotor 24 and the female rotor 26 rotate in the compression chamber 20, and the vapor is suctioned from the suction port 13. The male rotor 24 rotates counterclockwise (in the direction of the arrow A1) in FIG. 3, takes in vapor into the compression pocket formed by the claw parts 24a, and moves downward along the outer periphery of the compression chamber 20. The female rotor 26 rotates clockwise (in the direction of the arrow A2) in FIG. 3, takes in vapor into the compression pocket formed by the claw parts 26a, and moves downward along the outer periphery of the compression chamber 20. The compression pocket formed by the male rotor 24 and the compression pocket formed by the female rotor 26 merge at a center of a lower portion of the compression chamber 20, and the claw part 24a of the male rotor 24 enters the recessed part 26b of the female rotor 26 in the combined compression pocket to compress the vapor. The compressed vapor is discharged from the discharge port 15 to the outside.
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The phase adjustment of each of the rotors 24 and 26 during the assembly of the claw compressor is performed as follows.
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First, the key 35 is attached between the male rotor 24 and the first rotating shaft 32 in a state where the tip side (side of compression chamber 20) of the second housing 9 is open. As a result, the rotation is prevented by the key 35, and the relative position of the male rotor 24 in the rotation direction with respect to the first rotating shaft 32 is uniquely determined. The male rotor 24 is fastened to the first rotating shaft 32 by the first bolt 31.
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Next, the female rotor 26 is fastened to the second rotating shaft 42 by the second bolt 41. In this case, the second bolt 41 is used to perform the fastening after the position in the rotation direction with respect to the second rotating shaft 42 is adjusted to a desired value.
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The first housing 7 is attached to the tip side of the second housing 9 to form the compression chamber 20.
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The operations and effects of the present embodiment described above are as follows.
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In a case where the claw part 24a of the male rotor 24 enters the recessed part 26b of the female rotor 26 to compress the vapor, a larger torque is applied to the male rotor 24 than to the female rotor 26. Therefore, the relative rotation between the male rotor 24 and the first rotating shaft 32 is prevented by the key 35 to prevent the phase shift from the desired rotor angle. Meanwhile, the female rotor 26 can be fixed after the phase adjustment is performed in a case where the female rotor 26 is fastened to the end part of the second rotating shaft 42 by the second bolt 41. As a result, the phase of the male rotor 24 is determined to the desired value, and the phase of the female rotor 26 can be adjusted to the desired value, so that the claw compressor 1 having high compression efficiency and high reliability can be provided.
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A pin and a pin hole may be used instead of the key 35 and the key groove.
[Second Embodiment]
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Next, a second embodiment of the present disclosure will be described. In the present embodiment, a structure of and a method for assembling the claw compressor 1 that can perform relative positioning of the respective rotors 24 and 26 will be described. The present embodiment may be used together with the key 35 of the first embodiment, or may be used separately from the key 35 of the first embodiment. Therefore, in the following description, the same components as those in the first embodiment will be given the same reference numerals and description thereof will be omitted. Further, in the following description, the case of not using the key 35 of the first embodiment will be described.
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As shown in FIG. 4, first hole parts 24d into which a positioning pin is insertable are formed in the male rotor 24. The first hole parts 24d are formed such that an axis thereof is in a direction perpendicular to the end surface of the male rotor 24 (parallel to the first rotational axis O1). Two first hole parts 24d are symmetrically provided with the center (first rotational axis O1) of the male rotor 24 interposed therebetween. Each first hole part 24d is provided on an inner side of a first inscribed circle C1 that is in contact with a position having a smallest radius at a root of each claw part 24a. This is to avoid a compression loss to prevent the first hole parts 24d from passing through a region in which the compression pocket is formed in a case where the male rotor 24 rotates.
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Second hole parts 26d into which a positioning pin is insertable are formed in the female rotor 26. The second hole parts 26d are formed such that an axis thereof is in a direction perpendicular to the end surface of the female rotor 26 (parallel to the second rotational axis O2). Two second hole parts 26d are symmetrically provided with the center (second rotational axis O2) of the female rotor 26 interposed therebetween. Each second hole part 26d is provided on an inner side of a second inscribed circle C2 that is in contact with a position having a smallest radius at a root of each claw part 26a. This is to avoid a compression loss to prevent the second hole parts 26d from passing through a region in which the compression pocket is formed in a case where the female rotor 26 rotates.
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As shown in FIG. 5, first housing hole parts 9d1 are provided at positions corresponding to the respective first hole parts 24d in the second housing 9. In addition, second housing hole parts 9d2 are provided at positions corresponding to the respective second hole parts 26d in the second housing 9. As shown in FIG. 6, a positioning pin 50 is inserted in a state in which each first housing hole part 9d1 matches each first hole part 24d and in a state in which each second housing hole part 9d2 matches each second hole part 26d.
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In the claw compressor 1 having the above-described configuration, the respective rotors 24 and 26 are assembled as follows.
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As shown in FIG. 6, the positioning pin 50 is inserted by causing each first housing hole part 9d1 to match each first hole part 24d formed in the male rotor 24 in a state in which the first housing 7 is removed and the tip side (side of compression chamber 20) of the second housing 9 is opened (insertion step). The positioning pin 50 is inserted by causing each second housing hole part 9d2 to match each second hole part 26d formed in the female rotor 26 (insertion step).
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Next, the male rotor 24 is fastened to the first rotating shaft 32 by the first bolt 31 (fastening step). The female rotor 26 is fastened to the second rotating shaft 42 by the second bolt 41 (fastening step).
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The first housing 7 is attached to the tip side of the second housing 9 to form the compression chamber 20.
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The operations and effects of the present embodiment described above are as follows.
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The positioning pin 50 is inserted into the first hole parts 24d formed in the male rotor 24, and the positioning pin 50 is inserted into the second hole parts 26d formed in the female rotor 26, so that the relative position between the male rotor 24 and the female rotor 26 is fixed, and each of the rotors 24 and 26 is fastened to the corresponding rotating shafts 32 and 42 by the first bolt 31 and the second bolt 41. As a result, the clearance between the inner wall 9a of the compression chamber 20 and each of the rotors 24 and 26 can be managed by only the processing accuracy of the male rotor 24, each of the hole parts 24d, 26d, 9d1, and 9d2, and the female rotor 26, and the clearance can be made as small as possible, so that the performance can be improved.
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Only one first hole part 24d of the male rotor 24 attached to the first rotating shaft 32 that is the driving shaft may be provided. This is because the position of the male rotor 24 is determined by one first hole part 24d and the first bolt 31. In this case, it is preferable that two or more second hole parts are provided in the female rotor 26 attached to the second rotating shaft 42 that is the driven shaft. This is because the driven shaft has play in the rotation direction due to the backlash of the second timing gear 49.
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The two first hole parts 24d and two second hole parts 26d are symmetrically provided with the center of each of the rotors 24 and 26 interposed therebetween. As a result, the balance of the moment of inertia of the respective rotors 24 and 26 can be achieved.
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The positioning of each of the rotors 24 and 26 can be performed by inserting the positioning pin 50 into the aligned first hole parts 24d and first housing hole parts 9d1 and into the aligned second hole parts 26d and second housing hole parts 9d2. As a result, it is not necessary to use a jig that fixes a plurality of positioning pins corresponding to the first hole parts 24d and the second hole parts 26d, and the assembly is facilitated.
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However, as shown in FIG. 7, a jig 54 including a base 52 to which a plurality of positioning pins 50 inserted into the first hole parts 24d and the second hole parts 26d are fixed may be used. In this case, the first housing hole parts 9d1 and the second housing hole parts 9d2 are not necessary.
[Third Embodiment]
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Next, a third embodiment of the present disclosure will be described. The present embodiment relates to a shape of a tip of the claw part 24a of the male rotor 24, and is the same as the first embodiment except for this. Therefore, mainly the difference from the first embodiment will be described in the following description. The present embodiment can also be applied to the second embodiment.
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FIG. 9 shows an enlarged view in a portion B in FIG. 8. That is, FIG. 9 shows an enlarged view of a tip of the claw part 26a of the female rotor 26.
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As shown in FIG. 9, a tip 26e of the claw part 26a is retracted by the following retraction amount D from an intersection 26g of extension lines 26f of outlines on both sides that define an outer shape of the claw part 26a.
- Retraction amount D = BR × Rcy/PCD
- BR: backlash of timing gears 39 and 49
- Rcy: inner diameter of compression chamber 20
- PCD: pitch circle diameter of timing gears 39 and 49
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The inner diameter Rcy of the compression chamber 20 means an inner diameter (cylinder inner diameter) of the inner wall 9a defined about each of the rotational axes O1 and O2 as shown in FIG. 3.
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The tip 26e has an R shape connected to the outlines on both sides.
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According to the present embodiment, the following operations and effects are obtained.
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The claw part 26a may be bitten into a recessed part of the male rotor 24 that faces the claw part 26a by an amount corresponding to the backlash of the timing gears 39 and 49. Therefore, by giving the retraction amount D to the tip of the claw part 26a to avoid the contact between the tip 26e of the claw part 26a and the recessed part and to set the clearance as small as possible, the high efficiency can be achieved.
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The retraction amount D may be provided in the claw part 24a of the male rotor 24.
[Fourth Embodiment]
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Next, a fourth embodiment of the present disclosure will be described. The present embodiment relates to a seizure prevention coating, and is the same as the first embodiment except for this. Therefore, mainly the difference from the first embodiment will be described in the following description. The present embodiment can also be applied to the second embodiment and the third embodiment.
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As shown by a thick line in FIG. 10, a seizure prevention coating 60 is provided on the inner wall 9a that defines the compression chamber 20. As the seizure prevention coating, for example, a soft coating using a resin such as Teflon (registered trademark) can be used. In addition, an abradable coating that is machined while the claw parts 24a and 26a of the respective rotors 24 and 26 and the inner wall 9a are brought into contact with each other to form a desired clearance amount may also be used.
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According to the present embodiment, the following operations and effects are obtained.
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By applying the seizure prevention coating 60 to the inner wall 9a that defines the compression chamber 20, seizure in a case where each of the rotors 24 and 26 and the inner wall 9a are brought into contact with each other can be prevented. Since the risk of seizure is eliminated, the clearance can be reduced to reduce the leakage amount, and the high efficiency can be achieved.
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In addition, the seizure prevention coating may be applied to an outer peripheral surface of the male rotor 24 and/or the female rotor 26, more preferably to outer peripheral surfaces of the claw parts 24a and 26a.
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In each of the above-described embodiments, the male rotor 24 is the driving side and the female rotor 26 is the driven side, but the male rotor 24 may be the driven side and the female rotor 26 may be the driving side.
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The claw compressor and the method for assembling the same described in each of the embodiments described above are understood as follows, for example.
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A claw compressor (1) according to a first aspect of the present disclosure includes a first rotor (24) provided with a claw part (24a) protruding in a radial direction, a first rotating shaft (32) that rotatably supports the first rotor, a first bolt fastening part that fastens the first rotor to a shaft end of the first rotating shaft by means of a bolt (31), a second rotor (26) that rotates in a direction opposite to the first rotor and has a recessed part that receives the claw part during a compression step, a second rotating shaft (42) that rotatably supports the second rotor, a second bolt fastening part that fastens the second rotor to a shaft end of the second rotating shaft by means of a bolt (41), and a compression chamber (20) that accommodates the first rotor and the second rotor, in which a rotation prevention part (35) that prevents relative rotation between the first rotor and the first rotating shaft is provided.
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In a case where the claw part of the first rotor enters the recessed part of the second rotor to compress the fluid, a larger torque is applied to the first rotor than to the second rotor. Therefore, the relative rotation between the first rotor and the first rotating shaft is prevented by the rotation prevention part to prevent the phase shift from the desired rotor angle. Meanwhile, the second rotor can be fixed after the phase adjustment is performed in a case where the second rotor is fastened to the end part of the second rotating shaft by the second bolt fastening part. As a result, the phase of the first rotor is determined to the desired value, and the phase of the second rotor can be adjusted to the desired value, so that the claw compressor having high compression efficiency and high reliability can be provided.
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As the rotation prevention part, for example, a key and a key groove or a pin and a pin hole can be used.
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A claw compressor (1) according to a second aspect of the present disclosure includes a first rotor (24) provided with a claw part (24a) protruding in a radial direction, a first rotating shaft (32) that rotatably supports the first rotor, a first bolt fastening part that fastens the first rotor to a shaft end of the first rotating shaft by means of a bolt (31), a second rotor (26) that rotates in a direction opposite to the first rotor and has a recessed part that receives the claw part during a compression step, a second rotating shaft (42) that rotatably supports the second rotor, a second bolt fastening part that fastens the second rotor to a shaft end of the second rotating shaft by means of a bolt (41), and a compression chamber (20) that accommodates the first rotor and the second rotor, in which first hole parts (24d) into which a positioning pin (50) is insertable are formed in the first rotor, and second hole parts (26d) into which a positioning pin is insertable are formed in the second rotor.
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The positioning pin is inserted into the first hole parts formed in the first rotor, and the positioning pin is inserted into the second hole parts formed in the second rotor, so that the relative position between the first rotor and the second rotor is fixed, and each of the rotors is fastened to the corresponding rotating shafts by the first bolt fastening part and the second bolt fastening part. As a result, the clearance between the wall part of the compression chamber and each of the rotors can be managed by only the processing accuracy of the first rotor, a jig including the positioning pin, and the second rotor, and the clearance can be made as small as possible, so that the performance can be improved.
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In a case where one of the first rotating shaft and the second rotating shaft is a driving shaft and the other is a driven shaft provided via a gear, only one hole part may be provided in the rotor corresponding to the rotating shaft that is the driving shaft. This is because the position of the rotor is determined by one hole part and the bolt fastening part. In this case, it is preferable that two or more hole parts are provided in the rotor corresponding to the rotating shaft that is the driven shaft. This is because the driven shaft has play in the rotation direction due to the backlash of the gear.
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In a claw compressor (1) according to a third aspect of the present disclosure, in the first aspect or the second aspect, the first hole parts are symmetrically provided with a center of the first rotor interposed therebetween, and the second hole parts are symmetrically provided with a center of the second rotor interposed therebetween.
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The two first hole parts and two second hole parts are symmetrically provided with the center of each of the rotors interposed therebetween. As a result, the balance of the moment of inertia of the respective rotors can be achieved.
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A claw compressor (1) according to a fourth aspect of the present disclosure includes, in any one of the first to third aspects, a housing (7, 9) that forms the compression chamber, in which housing hole parts (9d1, 9d2) corresponding to the first hole parts and housing hole parts corresponding to the second hole parts are formed in the housing.
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The positioning of each of the rotors can be performed by inserting the positioning pin into the aligned housing hole parts and first hole parts and second hole parts. As a result, it is not necessary to use a jig that fixes a plurality of positioning pins corresponding to the first hole parts and the second hole parts, and the assembly is facilitated.
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A claw compressor (1) according to a fifth aspect of the present disclosure includes, in any one of the first to fourth aspects, timing gears (39, 49) that are fixed to the first rotating shaft and the second rotating shaft and mesh with each other, in which a tip of the claw part and/or a tip of a claw part of the second rotor is retracted by the following retraction amount D from an intersection of extension lines of outlines on both sides that define an outer shape of the tip of the claw part.
- Retraction amount D = BR × Rcy/PCD
- BR: backlash of the timing gears
- Rcy: inner diameter of the compression chamber
- PCD: pitch circle diameter of the timing gears
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The claw part may be bitten into a recessed part that faces the claw part by an amount corresponding to the backlash of the timing gears. Therefore, by giving the retraction amount to the tip of the claw part to avoid the contact between the tip of the claw part and the recessed part and to set the clearance as small as possible, the high efficiency can be achieved.
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In a claw compressor (1) according to a sixth aspect of the present disclosure, in any one of the first to fifth aspects, a seizure prevention coating (60) is provided on outer peripheral surfaces of the first rotor and the second rotor and/or on an inner wall that defines the compression chamber.
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By applying the seizure prevention coating to the outer peripheral surface of each of the rotors and/or the inner wall that defines the compression chamber, seizure in a case where the rotor and the inner wall are brought into contact with each other can be prevented. Since the risk of seizure is eliminated, the clearance can be reduced to reduce the leakage amount, and the high efficiency can be achieved.
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As the seizure prevention coating, for example, a soft coating using a resin such as Teflon (registered trademark) can be used. In addition, an abradable coating that is machined while the rotor and the inner wall are brought into contact with each other to form a desired clearance amount may also be used.
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A method for assembling a claw compressor according to the first aspect of the present disclosure is a method for manufacturing a claw compressor including a first rotor provided with a claw part protruding in a radial direction, a first rotating shaft that rotatably supports the first rotor, a first bolt fastening part that fastens the first rotor to a shaft end of the first rotating shaft by means of a bolt, a second rotor that rotates in a direction opposite to the first rotor and has a recessed part that receives the claw part, a second rotating shaft that rotatably supports the second rotor, a second bolt fastening part that fastens the second rotor to a shaft end of the second rotating shaft by means of a bolt, and a compression chamber that accommodates the first rotor and the second rotor, the method including: an insertion step of inserting a positioning pin into first hole parts formed in the first rotor and inserting a positioning pin into second hole parts formed in the second rotor; and a fastening step of fastening each of the bolts of the first bolt fastening part and the second bolt fastening part.
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In a method for assembling a claw compressor according to the second aspect of the present disclosure, in the method for assembling a claw compressor of the first aspect, in the insertion step, a jig (54) including the positioning pin inserted into the first hole parts, the positioning pin inserted into the second hole parts, and a base (52) to which the positioning pins are fixed is used.
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In a method for assembling a claw compressor according to the third aspect of the present disclosure, in the method for assembling a claw compressor of the first aspect, the claw compressor further includes a housing that forms the compression chamber, and housing hole parts corresponding to the first hole parts and housing hole parts corresponding to the second hole parts are formed in the housing, and in the insertion step, the positioning pin is inserted into the first hole parts and the housing hole parts corresponding to the first hole parts, and the positioning pin is inserted into the second hole parts and the housing hole parts corresponding to the second hole parts.
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It is not necessary to use a jig that fixes a plurality of positioning pins corresponding to the first hole parts and the second hole parts, and the assembly is facilitated.
Reference Signs List
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- 1: claw compressor
- 3: compression part
- 5: gear part
- 7: first housing
- 9: second housing
- 9a: inner wall
- 9d1: first housing hole part
- 9d2: second housing hole part
- 11: third housing
- 12: leg part
- 13: suction port
- 15: discharge port
- 20: compression chamber
- 21: gear chamber
- 22: O-ring
- 23: O-ring
- 24: male rotor (first rotor)
- 24a: claw part
- 24c: recess
- 24d: first hole part
- 26: female rotor (second rotor)
- 26a: claw part
- 26b: recessed part
- 26d: second hole part
- 26e: tip
- 26f: extension line
- 26g: intersection
- 31: first bolt
- 32: first rotating shaft
- 35: key (rotation prevention part)
- 37: tip-end-side bearing
- 38: rear-end-side bearing
- 39: first timing gear
- 41: second bolt
- 42: second rotating shaft
- 44: rear end cover
- 45: O-ring
- 47: tip-end-side bearing
- 48: rear-end-side bearing
- 49: second timing gear
- 50: positioning pin
- 52: base
- 54: jig
- 60: seizure prevention coating
- C1: first inscribed circle
- C2: second inscribed circle
- D: retraction amount
- O1: first rotational axis
- O2: second rotational axis
- Rcy: inner diameter of compression chamber