Assembly method of screw vacuum pump

Abstract

A method for assembling a screw vacuum pump includes pre-tightening the front end cover and the rear end cover of the body, and then tightening the front end cover and the rear end cover to accurately control the radial fit clearance between the female rotor and the male rotor by controlling the radial fit clearance between the female rotor and the male rotor through a feeler gauge, and then using an axial positioning device to find a reference to keep the axial fit clearance between the female rotor and the male rotor at zero, and then adjusting the axial clearance between the female rotor and the male rotor by installing a corresponding number of gaskets between a limit sleeve and a rear end bearing cover. The invention is simple and convenient to operate, has high assembly efficiency and qualified precision, can effectively reduce the maintenance cost of the screw vacuum pump, and improve the utilization efficiency of the screw vacuum pump.

Description

Technical Field

[0001] The invention relates to the field of chemical industry, and in particular to an assembly method of a screw vacuum pump. Background Art

[0002] The screw vacuum pump is a vacuum device that uses the suction and exhaust effects generated by a pair of screws rotating synchronously at high speed in the pump housing to evacuate the container to obtain a vacuum.

[0003] The maintenance content is not included in the random data of this type of equipment, and the maintenance manufacturer keeps the technical data and maintenance methods confidential. Therefore, this type of equipment has been sent out for repair and maintenance, which is costly and has a long maintenance cycle. During the outsourcing repair process, if the equipment in use fails, there is no spare equipment to replace it, which poses a great hidden danger to the stable operation of the device. Although the above problems can be avoided by self-maintenance, due to the high assembly accuracy requirements of the screw vacuum pump, the radial clearance and axial clearance of the positive and negative rotors of the vacuum pump cannot be guaranteed according to the conventional assembly method, resulting in reduced working efficiency of the vacuum pump after maintenance.

[0004] Therefore, how to ensure the assembly accuracy of the screw vacuum pump after self-maintenance is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to provide an assembly method of a screw vacuum pump in view of the deficiencies in the prior art, which is simple and convenient to operate, has high assembly efficiency and qualified precision, can effectively reduce the maintenance cost of the screw vacuum pump, and improve the utilization efficiency of the screw vacuum pump.

[0006] The technical solution of the present invention is: a method for assembling a screw vacuum pump, comprising the following steps:

[0007] 1) Assemble the disassembled and cleaned female rotor and male rotor into the inner cavity of the pump body, install the front cover at the front end of the pump body and the rear cover at the rear end of the pump body, so that the two ends of the female rotor can be rotatably supported in the corresponding bearings of the front cover and the rear cover, and the two ends of the male rotor can be rotatably supported in the corresponding bearings of the front cover and the rear cover, and pre-tighten the end cover mounting bolts;

[0008] 2) Insert a feeler gauge with a thickness of 0.1-0.2mm into the gap between the female rotor and the male rotor along the air inlet at the top of the pump body, maintain the radial position of the female rotor or the male rotor, adjust the radial position of the male rotor or the female rotor, clamp the feeler gauge, and tighten the end cover mounting bolts;

[0009] 3) The first synchronous gear and the second synchronous gear are simultaneously assembled on the front outwardly extending ends of the female rotor and the male rotor, the first synchronous gear is flush with the front outwardly extending end of the female rotor, and the second synchronous gear is flush with the front outwardly extending end of the male rotor, and they are meshed;

[0010] 4) Install limit sleeves on the rear extension ends of the female rotor and the male rotor respectively;

[0011] 5) Take an axial positioning device, which includes a positioning chuck and a mounting shaft arranged at the center of the positioning chuck, wherein the diameter of the positioning chuck is larger than the outer diameter of the first synchronous gear or the second synchronous gear, and the axial positioning device is fixedly mounted on the front outwardly extending end of the female rotor or the male rotor through the mounting shaft, and is in contact with the outer side surface of the first synchronous gear and the outer side surface of the second synchronous gear;

[0012] 6) Use the axial positioning device to push the female rotor and the male rotor backward into place;

[0013] 7) According to the assembly requirements of the screw vacuum pump, install a corresponding number of gaskets between the rear end cover bearing and the corresponding rotor limit sleeve;

[0014] 8) Install a protective shell on the front cover to protect the first synchronous gear and the second synchronous gear, install a limit shell on the rear cover to limit the axial position of the female rotor and the male rotor, remove the feeler gauge, and complete the assembly of the screw vacuum pump.

[0015] Preferably, the thickness of the feeler gauge in step 2) is 0.15 mm.

[0016] Furthermore, in step 3), both the first synchronous gear and the second synchronous gear are helical gears.

[0017] Furthermore, the middle parts of the front outwardly extending ends of the female rotor and the male rotor are both provided with threaded holes extending in the axial direction, and the axial positioning device in step 5) is fixedly connected by threaded cooperation between the mounting shaft and the threaded hole.

[0018] Preferably, in step 5), the diameter of the positioning chuck of the axial positioning device is smaller than the spacing distance between the female rotor and the male rotor.

[0019] The above technical solution has the following beneficial effects:

[0020] 1. The assembly method of the present invention has a simple and convenient operation process, low requirements on equipment, and can be directly assembled at the production site, effectively shortening the maintenance cycle of the screw vacuum pump, thereby improving the operating efficiency of the equipment. In addition, the assembly accuracy can be effectively guaranteed, thereby ensuring the normal operation of the screw vacuum pump after maintenance.

[0021] 2. The assembly method of the present invention can effectively and cost-effectively ensure the radial matching accuracy between the negative rotor and the positive rotor by pre-tightening the end cover mounting bolts, then inserting a feeler gauge with a thickness of 0.1-0.2 mm into the gap between the negative rotor and the positive rotor, maintaining the radial position of the negative rotor or the positive rotor, adjusting the radial position of the positive rotor or the negative rotor, clamping the feeler gauge, and tightening the end cover mounting bolts. The assembly process is convenient and reliable.

[0022] 3. The assembly method of the present invention, after the radial fitting accuracy of the female rotor and the male rotor is adjusted, uses the axial positioning device to synchronously push the female rotor and the male rotor backward into place, and then installs a corresponding number of gaskets between the rear end cover bearing and the limiting sleeve of the corresponding rotor according to the assembly requirements of the screw vacuum pump, and finally installs a limiting shell on the rear end cover to form an axial limit for the female rotor and the male rotor. The axial fitting clearance between the female rotor and the male rotor is kept at zero by finding a reference first, and then the axial fitting clearance between the female rotor and the male rotor is adjusted by installing a corresponding number of gaskets between the limiting sleeve and the rear end bearing cover. The axial fitting accuracy between the female rotor and the male rotor can be guaranteed efficiently and at a low cost, and the assembly process is convenient and reliable.

[0023] 4. A threaded hole extending axially is provided in the middle of the front outwardly extending end of the female rotor and the male rotor. The axial positioning device in step 5) is fixedly connected by threaded cooperation between the mounting shaft and the threaded hole. The installation and disassembly of the axial positioning device is simple and convenient, and the stability of the axial positioning device is ensured.

[0024] 5. Step 5) The diameter of the positioning chuck of the axial positioning device is smaller than the spacing distance between the female rotor and the male rotor. On the basis of ensuring that the reference surfaces of the female rotor and the male rotor are accurately located, interference with the front end cover is avoided to ensure smooth assembly process.

[0025] The following is a further description in conjunction with specific implementation methods. DETAILED DESCRIPTION

[0026] Example 1

[0027] First, disassemble the screw vacuum pump to be repaired, measure the data and mark it before disassembly, thoroughly clean the disassembled parts, check whether the parts have defects and repair or replace them. Preparation for assembly work includes the following steps:

[0028] 1) Assemble the disassembled and cleaned female rotor and male rotor into the inner cavity of the pump body, install the front cover at the front end of the pump body and the rear cover at the rear end of the pump body, so that the two ends of the female rotor can be rotatably supported in the corresponding bearings of the front cover and the rear cover, and the two ends of the male rotor can be rotatably supported in the corresponding bearings of the front cover and the rear cover, and pre-tighten the end cover mounting bolts;

[0029] 2) Insert a feeler gauge with a thickness of 0.15 mm into the gap between the female rotor and the male rotor along the air inlet at the top of the pump body, maintain the radial position of the female rotor or the male rotor, adjust the radial position of the male rotor or the female rotor, clamp the feeler gauge, and tighten the end cover mounting bolts;

[0030] 3) The first synchronous gear and the second synchronous gear are simultaneously assembled at the front outwardly extending ends of the female rotor and the male rotor. The first synchronous gear is flush with the front outwardly extending end of the female rotor, and the second synchronous gear is flush with the front outwardly extending end of the male rotor, and they are meshed. In this embodiment, the first synchronous gear and the second synchronous gear are both helical gears;

[0031] 4) Install limit sleeves on the rear outward ends of the female rotor and the male rotor respectively, and it is obvious that the positions of the limit sleeves correspond to each other;

[0032] 5) Take an axial positioning device, which includes a positioning chuck and a mounting shaft arranged at the center of the positioning chuck. The diameter of the positioning chuck is larger than the outer diameter of the first synchronous gear or the second synchronous gear, and smaller than the spacing distance between the female rotor and the male rotor. The axial positioning device is fixedly mounted on the front protruding end of the female rotor or the male rotor through the mounting shaft, and is fitted with the outer side surface of the first synchronous gear and the outer side surface of the second synchronous gear. In this embodiment, the middle part of the front protruding end of the female rotor and the male rotor is provided with a threaded hole extending in the axial direction. The axial positioning device is fixedly connected by threading the mounting shaft with the threaded hole;

[0033] 6) Use the axial positioning device to push the female rotor and the male rotor backward into place;

[0034] 7) According to the assembly requirements of the screw vacuum pump, install a corresponding number of gaskets between the rear end cover bearing and the corresponding rotor limit sleeve;

[0035] 8) Install a protective shell on the front cover to protect the first synchronous gear and the second synchronous gear, and install a limit shell on the rear cover. The limit shell cooperates with the limit sleeves at the rear ends of the negative rotor and the positive rotor to form an axial limit on the rear extended ends of the negative rotor and the positive rotor. Take out the feeler gauge to complete the assembly of the screw vacuum pump.

[0036] It has been verified by the applicant that the assembled screw vacuum pump meets the requirements of assembly accuracy.

Claims

1. A method for assembling a screw vacuum pump, characterized in that: The following steps are involved: 1) Assemble the disassembled and cleaned female rotor and male rotor into the inner cavity of the pump body, install the front cover at the front end of the pump body and the rear cover at the rear end of the pump body, so that the two ends of the female rotor can be rotatably supported in the corresponding bearings of the front cover and the rear cover, and the two ends of the male rotor can be rotatably supported in the corresponding bearings of the front cover and the rear cover, and pre-tighten the end cover mounting bolts; 2) Insert a feeler gauge with a thickness of 0.1-0.2mm into the gap between the female rotor and the male rotor along the air inlet at the top of the pump body, maintain the radial position of the female rotor or the male rotor, adjust the radial position of the male rotor or the female rotor, clamp the feeler gauge, and tighten the end cover mounting bolts; 3) The first synchronous gear and the second synchronous gear are simultaneously assembled on the front outwardly extending ends of the female rotor and the male rotor, the first synchronous gear is flush with the front outwardly extending end of the female rotor, and the second synchronous gear is flush with the front outwardly extending end of the male rotor, and they are meshed; 4) Install limit sleeves on the rear extension ends of the female rotor and the male rotor respectively; 5) Take an axial positioning device, which includes a positioning chuck and a mounting shaft arranged at the center of the positioning chuck, wherein the diameter of the positioning chuck is larger than the outer diameter of the first synchronous gear or the second synchronous gear, and the axial positioning device is fixedly mounted on the front outwardly extending end of the female rotor or the male rotor through the mounting shaft, and is in contact with the outer side surface of the first synchronous gear and the outer side surface of the second synchronous gear; 6) Use the axial positioning device to push the female rotor and the male rotor backward into place; 7) According to the assembly requirements of the screw vacuum pump, install a corresponding number of gaskets between the rear end cover bearing and the corresponding rotor limit sleeve; 8) Install a protective shell on the front cover to protect the first synchronous gear and the second synchronous gear, install a limit shell on the rear cover to limit the axial position of the female rotor and the male rotor, remove the feeler gauge, and complete the assembly of the screw vacuum pump.

2. The method for assembling a screw vacuum pump according to claim 1, characterized in that: Step 2) The thickness of the feeler gauge is 0.15 mm.

3. The method for assembling a screw vacuum pump according to claim 1, characterized in that: Step 3) The first synchronous gear and the second synchronous gear are both helical gears.

4. The method for assembling a screw vacuum pump according to claim 1, characterized in that: The middle parts of the front outwardly extending ends of the female rotor and the male rotor are both provided with threaded holes extending in the axial direction. In step 5), the axial positioning device is fixedly connected by threaded cooperation between the mounting shaft and the threaded hole.

5. The method for assembling a screw vacuum pump according to claim 1, characterized in that: Step 5) The diameter of the positioning chuck of the axial positioning device is smaller than the spacing distance between the female rotor and the male rotor.