Bearing anti-loosening device of screw compressor and screw compressor

Abstract

The application relates to a bearing anti-loosening device of a screw compressor and the screw compressor. The bearing anti-loosening device of the screw compressor comprises a shell and a rotor shaft, the rotor shaft is provided with a first bearing which is in interference fit and used for bearing axial load, the first bearing and the rotor shaft are both installed in the shell, and one side end face of an outer ring of the first bearing abuts against the shell; one detachable pressing block is arranged on the shell on both sides of the first bearing, an inner concave cavity is arranged in the pressing block, a circumferential side wall of the inner concave cavity is a matching surface, the matching surface is in arc surface shape and is in gap fit with a circumferential side wall of the outer ring of the first bearing, a front side wall of the inner concave cavity is a pressing surface, the pressing surface is a plane and is in pressing contact with the other side end face of the outer ring of the first bearing. The bearing anti-loosening device of the screw compressor is easy to assemble and can avoid axial movement of the rotor shaft during high-speed operation.

Description

Technical Field

[0001] The present invention relates to the technical field of screw compressors, and more specifically to a bearing anti-loosening device for a screw compressor and the screw compressor. Background Art

[0002] In a twin-screw compressor, the gap between the male and female rotors is controlled and adjusted by a synchronous gear. However, if the bearing installed on the rotor moves axially during the operation of the compressor, the rotor on which the moving bearing is located will also move axially, which will not only cause the axial position of the synchronous gear to shift, but also affect the meshing tooth gap between the male and female rotors. In severe cases, the male and female rotors may bite each other and damage the compressor.

[0003] To define the radial position of the yin-yang rotors, the prior art would place a bearing, such as a cylindrical roller bearing, on each rotor shaft at either end of the yin-yang rotor to support radial loads, with the inner ring of the bearing having an interference fit with the rotor shaft, while the outer ring would have an interference fit with the bearing seat within the housing. This would achieve radial positioning of the bearing and prevent radial displacement of the rotor shaft. To define the axial position of the yin-yang rotors, the prior art would place a bearing, such as a four-point angular contact bearing, on the rotor shaft of the yin-yang rotor to support axial loads. Similarly, the inner ring of the bearing would have an interference fit with the rotor shaft, while the outer ring of the bearing could have an interference fit or a clearance fit with the housing. One side of the inner ring of the bearing would rest against the shoulder of the rotor shaft, and a locking nut would be tightened on the other side of the bearing, pressing the locking nut against the other side of the inner ring of the bearing to achieve axial positioning of the bearing and the rotor shaft. Since the rotor shaft is prone to vibration during high-speed operation, this could cause the locking nut to loosen. Once the locking nut loosens, the axial positioning of the rotor shaft is lost, and the rotor shaft may experience axial movement, which is extremely harmful. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a bearing anti-loosening device for a screw compressor, which is not only easy to assemble but also can prevent the axial movement of the rotor shaft during high-speed operation.

[0005] The technical solution of the present invention is to provide a bearing anti-loosening device for a screw compressor, comprising a housing and a rotor shaft, wherein the rotor shaft is provided with a first bearing with an interference fit and used to bear an axial load, the first bearing and the rotor shaft are both installed in the housing, and one side end face of the outer ring of the first bearing rests on the housing; a detachable pressure block is respectively provided on both sides of the first bearing on the housing, an inner concave cavity is provided in the pressure block, the circumferential side wall of the inner concave cavity is a fitting surface, the fitting surface is in the shape of an arc surface and is clearance-fitted with the circumferential side wall of the outer ring of the first bearing, the front side wall of the inner concave cavity is a pressing surface, the pressing surface is a plane and is pressed against the other side end face of the outer ring of the first bearing.

[0006] Compared with the prior art, the bearing anti-loosening device of the screw compressor of the present invention has the following advantages: the first bearing can be installed on the rotor shaft first, and then pressure blocks are arranged on both sides of the first bearing to press the outer ring of the first bearing to achieve axial positioning of the first bearing. Compared with installing a locking nut on the rotor shaft, the assembly of the present invention is much easier; the pressure block and the housing can be directly fixed with two screws or locked with a bolt and a nut, and will not be easily loosened like a single locking nut connected to the rotor shaft. The contact between the pressure block and the outer ring of the first bearing is more reliable than the contact between the locking nut and the inner ring of the first bearing. The axial positioning of the first bearing is also reliable, and the axial movement of the rotor shaft during high-speed operation can be avoided. The pressure block is connected to the housing, and there is no need for fine processing of the rotor shaft. The pressure block and the circumferential side wall of the outer ring of the first bearing are clearance-matched, and only the pressing surface is pressed against the outer ring of the first bearing. The processing accuracy requirements for the matching surface and the pressing surface are not high, production and processing are convenient, and the processing cost is also low.

[0007] Preferably, the pressing surface is provided with a pressing threaded hole, a pressing pin is threadedly connected to the inner surface of the pressing threaded hole, and a limiting groove or limiting hole is provided on the end surface of the outer ring of the first bearing opposite to the pressing threaded hole. The pressing pin is inserted into the limiting groove or limiting hole and abuts and presses against the outer ring of the first bearing. With this structure, the outer ring of the first bearing can be circumferentially limited by inserting the pressing pin into the limiting groove or limiting hole and abutting and pressing against the outer ring of the first bearing, thereby preventing the outer ring of the first bearing from rotating with the inner ring and generating a large amount of frictional heat or even wear.

[0008] Preferably, the bottom of the limiting groove is an inclined surface, and the height of the inclined surface gradually decreases from the inside of the outer ring of the first bearing to the outside of the outer ring of the first bearing. With this structure, the pressing pin gradually moves from the inside of the outer ring of the first bearing to the outside of the outer ring of the first bearing during the gradual tightening process, so that the pressing pin does not cause plastic damage to the bottom of the limiting groove during the process of abutting against the bottom of the limiting groove.

[0009] Preferably, the pressing block is connected to the housing by bolts. With this structure, the pressing block can be easily assembled and disassembled.

[0010] The technical problem to be solved by the present invention is to provide a screw compressor which is not only easy to assemble but also can prevent the axial movement of the male and female rotors during high-speed operation.

[0011] The technical solution of the present invention is to provide a screw compressor, including a shell and a male rotor and a female rotor installed in the shell, a rotor shaft is provided at both ends of the male rotor and the female rotor, and a second bearing with an interference fit and used to bear radial load is provided on the rotor shaft, a bearing seat is provided in the shell, and the second bearing is installed in the bearing seat with an interference fit; it is characterized in that the rotor shafts at the power input ends of the male rotor and the female rotor are provided with the bearing anti-loosening device of the screw compressor as described above, and the first bearing is arranged on the outside of the bearing seat.

[0012] Compared with the prior art, the screw compressor of the present invention has the following advantages: on the rotor shafts of the male rotor and the female rotor, the second bearing is used to bear the radial load and the first bearing is used to bear the axial load. The first bearing is arranged on the outside of the bearing seat, so that the assembly of the first bearing and the pressure block in the housing is relatively convenient. Pressure blocks are arranged on both sides of the first bearing to press the outer ring of the first bearing to achieve axial positioning of the first bearing, thereby achieving axial positioning of the rotor shaft, that is, achieving axial positioning of the male rotor and the female rotor respectively. Compared with installing a locking nut on the rotor shaft, the bearing anti-loosening device of the screw compressor of the present invention is much easier to assemble; the pressure block The housing can be directly fixed with two screws or locked with bolts and nuts. It will not loosen easily like a single locking nut connected to the rotor shaft. The contact between the pressure block and the outer ring of the first bearing is more reliable than the contact between the locking nut and the inner ring of the first bearing. The axial positioning of the first bearing is also reliable, which can prevent the rotor shaft from axial movement during high-speed operation. The pressure block is connected to the housing and does not require fine processing of the rotor shaft. The pressure block and the circumferential side wall of the outer ring of the first bearing are clearance-matched, and only the clamping surface is pressed against the outer ring of the first bearing. The processing accuracy requirements for the matching surface and the clamping surface are not high, production and processing are convenient, and the processing cost is also low.

[0013] Preferably, the first and second bearings are positioned opposite each other, with a washer positioned on the rotor shaft between them. The pressure block and washer are located on either side of the first bearing, with both sides of the washer contacting one end face of the inner ring of the first bearing and the inner ring of the second bearing, respectively; the other end face of the inner ring of the second bearing rests on the shoulder of the rotor shaft. With this structure, the first bearing can withstand axial forces. The force applied by the pressure block to the outer ring of the first bearing is transmitted to the inner ring of the first bearing via the rollers and bracket within the bearings. The inner ring of the first bearing, the washer, the inner ring of the second bearing, and the shoulder of the rotor shaft are pressed against each other, thus completing the axial positioning of the first bearing relative to the second bearing.

[0014] Preferably, a sleeve is provided on the rotor shaft on the other side of the second bearing's inner ring. The two sides of the sleeve respectively contact the other end surface of the second bearing's inner ring and the rotor shaft shoulder. With this structure, the first bearing's inner ring, washer, second bearing's inner ring, sleeve, and rotor shaft shoulder are pressed against each other, effectively positioning the first bearing axially relative to the second bearing.

[0015] Preferably, a detachable pad is provided between the housing and the pressure block, and the pad is pressed against the housing by the pressure block. With this structure, the pressure block does not directly contact the housing but is instead pressed against the pad, which helps reduce the machining accuracy of the contact surface on the housing and facilitates fine machining of the pad. Furthermore, the provision of the pad can reduce the sidewall width of the inner concave cavity of the pressure block, making the sidewall width of the inner concave cavity of the pressure block smaller than the width of the outer ring of the first bearing. This also allows the front sidewall of the inner concave cavity to be pressed against the end face of the outer ring of the first bearing, which helps reduce the machining accuracy of the pressure block.

[0016] Preferably, the pad and the pressure block are provided with opposing threaded mounting holes, the threaded mounting holes being threadedly connected with mounting screws, and the pressure block, the pad and the housing are pressed against each other by the mounting screws. This structure facilitates the connection and mutual pressing of the pressure block, the pad and the housing.

[0017] Preferably, the outer ring of the first bearing is pressed against the cushion block. With this structure, the outer ring of the first bearing and the cushion block are not in direct contact with the housing, but are pressed against the cushion block, which helps to reduce the machining accuracy of the contact surface on the housing and is also more convenient for fine machining of the cushion block. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic cross-sectional structure diagram of the bearing anti-loosening device of the screw compressor of the present invention.

[0019] Figure 2 It is a schematic diagram of the assembly structure of the pressure block and the bearing in the present invention.

[0020] Figure 3 for Figure 2 AA direction cross-section diagram.

[0021] Figure 4 for Figure 2 Exploded diagram.

[0022] As shown in the figure: 1. Shell, 2. Male rotor, 3. Female rotor, 3-1. Rotor shaft, 4. Bushing, 5. Second bearing, 6. First bearing, 6-1. Limiting groove, 7. Washer, 8. Spacer, 9. Pressing block, 9-1. Fitting surface, 9-2. Pressing surface, 9-3. Pressing threaded hole, 9-4. Mounting threaded hole. DETAILED DESCRIPTION

[0023] In order to better understand the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of exemplary embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0024] In the drawings, the thickness, size and shape of objects have been slightly exaggerated for ease of explanation. The drawings are only examples and are not drawn strictly to scale.

[0025] It should also be understood that the terms "comprising," "having," "including," and "containing," when used in this specification, indicate the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. Furthermore, expressions such as "...at least one of" when following a list of listed features modify the entire list, rather than modifying the individual elements in the list.

[0026] Example 1:

[0027] The screw compressor of the present invention comprises a housing 1 and a male rotor 2 and a female rotor 3 installed in the housing 1. Both ends of the male rotor 2 and the female rotor 3 are provided with rotor shafts. The rotor shafts are provided with second bearings with interference fit and for bearing radial loads. The second bearings can be cylindrical roller bearings. The male rotor 2 and the female rotor 3 are also provided with bearing anti-loosening devices of the screw compressor of the present invention at the power input end, such as Figure 1 As shown in , the bearing arrangements on the male rotor 2 and the female rotor 3 are the same, and the following description will be made taking the female rotor 3 as an example.

[0028] A second bearing 6 for bearing radial loads and a first bearing 5 for bearing axial loads are provided on the rotor shaft 3-1 at the power input end of the female rotor 3. The inner ring of the first bearing 5 and the inner ring of the second bearing 6 are both interference fit with the rotor shaft 3-1. In this embodiment, the second bearing 6 adopts a cylindrical roller bearing, and the first bearing 5 adopts a four-point angular contact bearing. A bearing seat is provided in the housing 1, and the outer ring of the second bearing 6 is interference fit with the inner cavity of the bearing seat. The first bearing 5 is located on the outside of the bearing seat and is arranged opposite to the second bearing.

[0029] like Figures 1 to 4As shown in FIG, two spacers 8 are provided on the outer side of the bearing seat of the housing. Both spacers 8 are fixed to the housing with bolts or screws and are opposite to one side of the outer ring of the first bearing 5. Two pressure blocks 9 are provided on the housing on the other side of the outer ring of the first bearing 5. The two pressure blocks 9 are respectively located on the upper and lower sides or the left and right sides of the first bearing 5 and correspond one-to-one with the two spacers 8. The spacers 8 and pressure blocks 9 are also provided with two corresponding mounting threaded holes 9-4. The internal threads of the two mounting threaded holes 9-4 are connected to mounting screws. The mounting screws pass through the pressure blocks 9 and the spacers 8 and are threadedly connected to the housing, thereby pressing the pressure blocks 9, the spacers 8 and the housing 1 against each other. The mounting screws can also be locked with a fastening nut after passing through the housing, making the connection between the pressure blocks 9, the spacers 8 and the housing more reliable. An inner concave cavity is provided in the pressure block 9, and the circumferential side wall of the inner concave cavity is a mating surface 9-1. The mating surface 9-1 is in the shape of an arc surface and is gap-matched with the circumferential side wall of the outer ring of the first bearing 5. The inner concave cavity is provided with a front side wall but no rear side wall. The front side wall is a clamping surface 9-2. The clamping surface 9-2 is a plane and is pressed against the end face of the outer ring of the first bearing 5, so that the outer ring of the first bearing 5 is also pressed against the gasket 8. In this way, the housing 1, the two gaskets 8, the rotor shaft, the first bearing 5 and the two pressure blocks 9 constitute the bearing anti-loosening device of the screw compressor of the present invention, which realizes the axial positioning of the first bearing 5, the rotor shaft 3-1 and the female rotor 3, and the axial positioning is reliable, which can prevent the rotor shaft 3-1 and the female rotor 3 from axial movement during high-speed operation.

[0030] In the screw compressor bearing anti-loosening device of the present invention, a compression threaded hole 9-3 is further provided on the compression surface 9-2, into which a compression pin is threadedly connected. A retaining groove 6-1 is provided on the end surface of the outer ring of the first bearing 5, opposite to the compression threaded hole 9-3. The compression pin is inserted into the retaining groove 6-1 and abuts against the outer ring of the first bearing 5, thereby circumferentially retaining the outer ring of the first bearing 5 and preventing the outer ring of the first bearing 5 from rotating with the inner ring and generating a large amount of frictional heat or even wear. The bottom of the retaining groove 6-1 is an inclined surface, and the height of the inclined surface gradually decreases from the inside of the outer ring of the first bearing 5 to the outside of the outer ring of the first bearing 5. As the compression pin is gradually tightened, it gradually moves along the bottom of the retaining groove 6-1 from the inside of the outer ring of the first bearing 5 to the outside of the outer ring of the first bearing 5. This ensures that the retaining groove 6-1 bottom does not plastically damage the retaining groove bottom during the compression pin's abutment with the retaining groove bottom. The limiting groove 6 - 1 can also be configured as a limiting hole. As long as the pressing pin passes through the pressing block 9 and is inserted into the limiting hole, the outer ring of the first bearing 5 can be limited in the circumferential direction.

[0031] A shoulder opposite to the second bearing 6 is provided on the rotor shaft 3-1. A sleeve 4 is sleeved between the shoulder and the second bearing 6 on the rotor shaft 3-1. A washer 7 is provided between the second bearing 6 and the first bearing 5 on the rotor shaft 3-1. The inner ring of the first bearing 5, the washer 7, the inner ring of the second bearing 6, the sleeve 4 and the shoulder of the rotor shaft 3-1 are in contact with and pressed against each other in sequence. In this way, the first bearing 5 completes the axial positioning of the second bearing 6.

[0032] Example 2:

[0033] The difference between the bearing anti-loosening device of the screw compressor in this embodiment and that in embodiment 1 is that no pad is provided on the outer side of the bearing seat on the shell, and the pressure block 9 is directly mounted on the shell 1 by bolts. The two end faces of the outer ring of the first bearing 5 are respectively pressed against the shell 1 and the pressing surface 9-2 of the pressure block 9. In this way, the pressure block 9 and the shell 1 are connected by two mounting screws, or are connected by two bolts and fastening nuts are installed on the bolts to tighten and lock them, so that the bearing anti-loosening device of the screw compressor in this embodiment can reliably position the axial direction of the first bearing 5, thereby preventing the rotor shaft 3-1 and the female rotor 3 from axial movement during high-speed operation.

[0034] In addition, if the second bearing 6 is not axially positioned by the first bearing 5, the second bearing 6 can also be axially positioned by providing a locking nut on the rotor shaft to press the inner ring of the second bearing 6 against the shoulder of the rotor shaft.

[0035] The above are only specific embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced with equivalents without departing from the spirit and scope of the present invention, they should be included in the scope of protection of the claims of the present invention.

Claims

1. A bearing anti-loosening device for a screw compressor, comprising a housing and a rotor shaft, wherein the rotor shaft is provided with a first bearing having an interference fit and configured to bear an axial load, the first bearing and the rotor shaft being both mounted within the housing, with one end face of an outer ring of the first bearing abutting against the housing; characterized in that: A detachable pressure block is respectively provided on both sides of the first bearing on the shell, and an inner concave cavity is provided in the pressure block, and the circumferential side wall of the inner concave cavity is a matching surface, and the matching surface is in the shape of an arc surface and is gap-matched with the circumferential side wall of the outer ring of the first bearing, and the front side wall of the inner concave cavity is a clamping surface, and the clamping surface is a plane and is clamped to the other side end face of the outer ring of the first bearing; a clamping threaded hole is provided on the clamping surface, and a clamping pin is connected to the inner thread of the clamping threaded hole, and a limiting groove or limiting hole opposite to the clamping threaded hole is provided on the end face of the outer ring of the first bearing, and the clamping pin is inserted into the limiting groove or limiting hole and is pressed against the outer ring of the first bearing; the bottom of the limiting groove is an inclined surface, and the height of the inclined surface gradually decreases from the inside of the outer ring of the first bearing to the outside of the outer ring of the first bearing.

2. The screw compressor bearing anti-loosening device according to claim 1, characterized in that: The pressing block is connected to the shell through bolts.

3. A screw compressor comprising a housing and a male rotor and a female rotor mounted within the housing, wherein a rotor shaft is provided at both ends of the male rotor and the female rotor, wherein a second bearing having an interference fit and configured to bear a radial load is provided on each of the rotor shafts, wherein a bearing seat is provided within the housing, and wherein the second bearing is installed within the bearing seat with an interference fit; wherein: The rotor shafts at the power input ends of the male rotor and the female rotor are both provided with the bearing anti-loosening device of the screw compressor as claimed in claim 1 or 2, and the first bearing is arranged on the outside of the bearing seat.

4. The screw compressor according to claim 3, characterized in that The first bearing and the second bearing are arranged opposite to each other, and a washer is arranged on the rotor shaft between the first bearing and the second bearing. The pressure block and the washer are respectively located on both sides of the first bearing, and the two sides of the washer respectively contact with the inner ring of the first bearing and one side end face of the inner ring of the second bearing; the other side end face of the inner ring of the second bearing rests on the shoulder of the rotor shaft.

5. The screw compressor according to claim 4, characterized in that A shaft sleeve is provided on the rotor shaft on the other side of the inner ring of the second bearing, and two sides of the shaft sleeve respectively contact the other side end surface of the inner ring of the second bearing and the shaft shoulder of the rotor shaft.

6. The screw compressor according to claim 3, characterized in that A detachable cushion block is provided between the shell and the pressing block, and the cushion block is pressed tightly against the shell by the pressing block.

7. The screw compressor according to claim 6, characterized in that The cushion block and the pressing block are provided with opposite mounting threaded holes, the mounting threaded holes are internally threadedly connected with mounting screws, and the pressing block, the cushion block and the housing are pressed against each other by the mounting screws.

8. The screw compressor according to claim 6, characterized in that The outer ring of the first bearing is pressed tightly against the cushion block.

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