阅读说明：本技术 用于精密结构装配的装置和用于分子泵配重的方法 (Device for precision structure assembly and method for molecular pump counterweight ) 是由 顾艳庆 李赏 于 2021-09-10 设计创作，主要内容包括：本发明提供一种用于精密结构装配的装置,解决了现有技术中精密结构装配效率低,装配装置结构复杂的技术问题。本发明提供的一种用于分子泵配重的方法,能够满足动平衡的过程中各个方向、不同角度的配重孔位的加减配重需要,解决了螺钉对不正、不能顺利装配到孔位里的问题。(The invention provides a device for assembling a precision structure, which solves the technical problems of low precision structure assembling efficiency and complex structure of an assembling device in the prior art. The method for balancing the weight of the molecular pump can meet the requirements of adding and subtracting weights of weight hole positions in different directions and different angles in the process of dynamic balance, and solves the problems that the screw pair is not correct and the screw pair cannot be smoothly assembled in the hole positions.)

1. An apparatus for precision structural assembly, comprising:

the operating component can be used for assembling a fastening piece into a mounting hole in the precision structure, a first thread rotating along a first direction is arranged on the circumferential direction of the inner circumferential wall of the mounting hole, and a second thread matched with the first thread is arranged at one end of the fastening piece;

the guide part is a cavity with openings at two ends and can be sleeved on the periphery of the operation part, and one end of the guide part is provided with a first limiting structure; the first stopper structure may stop the other end of the fastener to the guide member, and the other end of the fastener may be separated from the guide member as the first and second threads are assembled.

2. The apparatus for precision structural assembly of claim 1, wherein the operating member is a screwdriver, the screwdriver including a handle and a shaft connected to the handle; a second limiting structure is arranged at one end, far away from the handle, of the rod part, and the second limiting structure is matched with a third limiting structure at the top of the other end of the fastener to work, so that the fastener can be operated by the screwdriver;

the guide component is a guide sleeve, and the first limiting structure is a third thread which is arranged on the circumferential direction of the inner wall surface of the guide sleeve and rotates along the first direction; and a fourth thread matched with the third thread is arranged at the other end of the fastener.

3. The apparatus for precision structural assembly of claim 2, wherein the guide sleeve comprises a first cylinder provided with a third thread and a second cylinder connected to the first cylinder, wherein the first cylinder has an inner diameter larger than that of the second cylinder, and at least one set of the third thread is provided on an inner wall surface of the first cylinder.

4. The apparatus for precision structural assembly of claim 3, wherein the plurality of third threads provided on the inner wall surface of the first cylinder are different in size such that the cross section of the first cylinder has a stepped structure and the cross section is formed in a horn shape as a whole.

5. The apparatus for precision structural assembly of claim 2, wherein the length of the guide sleeve is less than the overall length of the screwdriver.

6. The apparatus for precision structural assembly of claim 2, wherein the guide sleeve and the screwdriver are of a split construction.

7. The apparatus for precision structural assembly of claim 6, wherein the apparatus for precision structural assembly comprises one of the screw drivers and a plurality of guide sleeves cooperating with the screw drivers, wherein the plurality of guide sleeves are provided with the third threads of different sizes.

8. An apparatus for precision structural assembly according to claim 2, wherein the length of the third thread is not less than one third of the overall length of the fastener.

9. An apparatus for precision structural assembly according to any of claims 1-8, wherein the precision structural assembly is a counterweight assembly of a molecular pump, the fastener is a counterweight screw, the mounting hole is a counterweight port provided on an impeller of a turbine of the molecular pump, and a central axis of the counterweight port forms an angle α with a center of the turbine, and 60 ° ≦ α ≦ 90 °.

10. A method for molecular pump weighting, comprising:

fitting one end of a balance weight screw to a third thread of one end of a guide sleeve in an apparatus for precision structure fitting, the third thread being rotated in a first direction;

the rod part of a screwdriver in the device for assembling the precise structure is deeply inserted into the guide sleeve through the other end of the guide sleeve and is limited together with the top of a counterweight screw assembled on the guide sleeve, and a first thread rotating along the first direction is arranged in the counterweight hole;

aligning one end of the counterweight screw, which is far away from the guide sleeve, with a counterweight hole on the molecular pump;

rotating the screwdriver in a first direction to screw one end of the weight screw into the weight port while screwing the other end of the weight screw out in a direction away from the guide cylinder until at least one third of the weight screw is screwed into the weight port and the other end of the weight screw is disengaged from the guide cylinder until the weight screw is fully rotated into the weight port.

Technical Field

The invention relates to the technical field of precision structure assembly, in particular to a device for precision structure assembly and a method for balancing weight of a molecular pump.

Background

The precision structure causes a problem of low assembling efficiency due to the limitation of assembling space during the assembling process. The following is a detailed description of the problems encountered during the weighting process of this precise structure of the molecular pump: the impeller of the molecular pump needs to use counterweight screws with different specifications in the process of adding or subtracting counterweight, but due to the impeller structure, the screw installation position and the like, the counterweight screws fall into the inside of a product in the assembly process, and therefore the counterweight screws need to be aligned to the direction of the counterweight holes, so that the counterweight screws are prevented from falling into the inside of the product. In the prior art, the following two methods are commonly used in the assembly process of the counterweight screw of the molecular pump: the first method is that a screw is clamped by tweezers, and meanwhile, a screwdriver is matched to complete the assembly of a balance weight screw; and the other method is that the counterweight screw is firstly placed in the heat shrinkable tube, so that the counterweight screw is aligned with the counterweight hole, and then the assembly of the counterweight screw is completed by matching with a screwdriver. However, in any of the above methods, there are problems that the taking and placing of the weight screw are difficult, the weight screw is difficult to align with the weight hole, and the weight screw is easy to fall off in the tweezers or the heat shrinkable tube, which causes a problem of low assembly efficiency in the weight balancing process of the molecular pump.

Therefore, it is urgently needed to provide a new solution to the problem of low assembly efficiency in a precise structure.

Disclosure of Invention

In view of the above, embodiments of the present invention are directed to an apparatus for assembling a precision structure and a method for balancing a molecular pump, so as to solve the problem of low precision structure assembling efficiency in the prior art.

In a first aspect the present application provides an apparatus for precision structure assembly comprising:

the operating component can be used for assembling the fastening piece into an installation hole in the precision structure, a first thread rotating along a first direction is arranged on the circumferential direction of the inner circumferential wall of the installation hole, and a second thread matched with the first thread is arranged at one end of the fastening piece;

the guide part is a cavity with openings at two ends and can be sleeved on the periphery of the operation part, and one end of the guide part is provided with a first limiting structure; the first retaining structure may retain the other end of the fastener to the guide member, and the other end of the fastener may be disengaged from the guide member following the assembly of the first and second threads.

In one embodiment, the operating member is a screwdriver, the screwdriver including a handle and a shaft connected to the handle; a second limiting structure is arranged at one end, far away from the handle, of the rod part, and the second limiting structure is matched with a third limiting structure at the top of the other end of the fastener to work, so that the operation of the screwdriver on the fastener is realized;

the guide component is a guide sleeve, and the first limiting structure is a third thread which is arranged on the inner wall surface of the guide sleeve and rotates along the first direction in the circumferential direction; the other end of the fastener is provided with a fourth thread matched with the third thread.

In one embodiment, the guide sleeve comprises a first cylinder body provided with third threads and a second cylinder body connected with the first cylinder body, wherein the inner diameter of the first cylinder body is larger than that of the second cylinder body, and at least one set of third threads is arranged on the inner wall surface in the first cylinder body.

In one embodiment, the third threads disposed on the inner wall surface of the first cylinder have different sizes, so that the cross section of the first cylinder has a step structure, and the whole cross section is horn-shaped.

In one embodiment, the length of the guide sleeve is less than the overall length of the screwdriver.

In one embodiment, the guide sleeve and the screwdriver are of a split structure.

In one embodiment, the means for precision structural assembly comprises a screwdriver and a plurality of guide sleeves cooperating with the screwdriver, wherein the plurality of guide sleeves are provided with third threads of different sizes.

In one embodiment, the length of the third thread is no less than one third of the overall length of the fastener.

In one embodiment, the precision structure assembly is a counterweight assembly of the molecular pump, the fastener is a counterweight screw, the mounting hole is a counterweight hole arranged on an impeller of a turbine of the molecular pump, an included angle alpha is formed between a central axis of the counterweight hole and the center of the turbine, and the included angle alpha is more than or equal to 60 degrees and less than or equal to 90 degrees.

In a second aspect, the present application also provides a method for molecular pump weighting, comprising:

fitting one end of a balance weight screw to a third thread of one end of a guide sleeve in an apparatus for precision structure fitting, the third thread being rotated in a first direction;

the rod part of a screwdriver in the device for assembling the precise structure is deeply inserted into the guide sleeve through the other end of the guide sleeve and is limited together with the top of a counterweight screw assembled on the guide sleeve, and a first thread rotating along a first direction is arranged in a counterweight hole;

aligning one end of the counterweight screw, which is far away from the guide sleeve, with a counterweight hole on the molecular pump;

and rotating the screwdriver along the first direction to enable one end of the counterweight screw to be screwed into the counterweight hole and simultaneously to enable the other end of the counterweight screw to be screwed out in the direction far away from the guide cylinder until at least one third of the counterweight screw is screwed into the counterweight hole, and separating the other end of the counterweight screw from the guide cylinder until the counterweight screw is completely rotated into the counterweight hole.

The application provides a device for precision structure assembly, cooperation work through operating means and guide part has not only solved the problem of assembling inefficiency, difficult operation in the precision structure device, and simultaneously, the device has simple structure, the part is few, low in production cost and portable's advantage. The application also provides a method for balancing the weight of the molecular pump, and in the method, the weight holes in all directions in the process of balancing the weight of the molecular pump can be met through positioning and guiding the weight screws, so that the requirement of adding and subtracting the weight of the weight holes at different angles is met, and the problem that the weight cannot be smoothly assembled to the weight holes due to the fact that the screw pairs are not correct is solved.

Drawings

Fig. 1 is a schematic structural diagram of an apparatus for precision structure assembly according to an embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of an apparatus for precision structure assembly according to an embodiment of the present application.

Fig. 3 is a partially enlarged view of a device for precision structure assembly according to an embodiment of the present application in use.

Fig. 4 is a schematic structural diagram of a turbine of a molecular pump according to an embodiment of the present disclosure.

Fig. 5 is an enlarged view of a portion a in fig. 4.

1-fastener, 11-second thread; 12-fourth thread; 2-a guide sleeve, 21-a first cylinder; 22-a second cylinder; 23-a third thread; 3-a screwdriver; 31-a handle; 32-a stem portion; 4-a weight port; 41-first thread.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

Exemplary devices

As shown in fig. 1 to 3, an exemplary embodiment of the present application provides an apparatus for precision structure assembly, which includes an operating member and a guide member.

In one embodiment, the operating component can be used for assembling the fastening piece 1 into a mounting hole on a precision structure, a first thread 41 rotating along a first direction is arranged on the circumferential direction of the inner circumferential wall of the mounting hole, and a second thread 11 matched with the first thread 41 is arranged at one end of the fastening piece 1; the guide part is a cavity with openings at two ends and can be sleeved on the periphery of the operation part, and one end of the guide part is provided with a first limiting structure; the first stopping structure may stop the other end of the fastening member 1 to the guide member, and the other end of the fastening member 1 may be separated from the guide member as the first and second threads 41 and 11 are assembled.

In the process of using the device for precision structure assembly, after the first limiting structure limits the other end of the fastener 1 in the cavity at one end of the guide part, the operating part enters the cavity through the other end of the guide part. Then, while screwing one end of the fastening member 1 into the mounting hole by the operating member, the other end of the fastening member 1 is moved in a direction to be separated from the guide member until the fastening member 1 is separated from the cavity of the guide member, and then the fastening member 1 is fitted into the mounting hole. The guide component is utilized to realize the fixing and installation guiding effects on the fastener 1, and the assembly efficiency is greatly improved.

Regarding the technical solutions of how the first limit structure can limit the position of the fastener 1 and how the first thread 41 and the second thread 11 are matched to realize the efficient assembly of the fastener 1, in one embodiment, the following technical solutions can be adopted: the operating part is a screwdriver 3, and the screwdriver 3 comprises a handle 31 and a rod part 32 connected with the handle 31; a second limiting structure is arranged at one end, far away from the handle 31, of the rod part 32, and the second limiting structure is matched with a third limiting structure at the top of the other end of the fastener 1 to work, so that the operation of the screwdriver 3 on the fastener 1 is realized; the guide component is the guide sleeve 2, and the first limiting structure is a third thread 23 which is arranged on the circumferential direction of the inner wall surface of the guide sleeve 2 and rotates along the first direction. The other end of the fastener 1 is provided with a fourth thread 12 cooperating with the third thread 23. The first threads 41 and the third threads 23 which are arranged along the first direction in the same rotating direction are matched with the threads at the two ends of the fastening piece 1 and the threads of the mounting hole, so that the guiding effect on the fastening piece 1 in the mounting process is ingeniously realized, and meanwhile, the structural design of the device is greatly reduced, so that the technical problems that the precision structure is low in assembly efficiency and the assembly tool used in the assembly process is complex are solved.

In one embodiment, the guide sleeve 2 is a metallic material. The metal guide sleeve not only can better realize the guide function, but also is convenient to process, thereby saving the production cost.

In one embodiment, the specific structure of the device comprises a screwdriver 3 and a metal guide sleeve 2 cooperating with the screwdriver 3. In use of the device, the shaft 32 of the screwdriver 3 is fitted inside the guide sleeve 2 and the shank of the screwdriver 3 is outside the guide sleeve 2, thereby facilitating the operation of the screwdriver. Wherein the clearance between the inner diameter of the guide sleeve and the outer diameter of the shaft part 32 of the screwdriver 3 is 0.20mm-0.50 mm. In an embodiment the clearance between the inner diameter of the guide sleeve and the outer diameter of the shaft 32 of the screwdriver 3 is 0.35mm, which clearance arrangement can increase the speed of the insertion and removal of the screwdriver 3 relative to the guide sleeve 2. The internal thread provided in the guide sleeve, i.e., the third thread 23, can prevent the problem of the falling-off of the weight screw.

In one embodiment, the screwdriver 3 is made of metal, and the screwdriver 3 includes a shaft 32 and a handle 31, wherein the length of the shaft 32 is 120.00mm, the length of the handle 31 is 50.00mm, and the handle is knurled. When the screwdriver 3 is used, the length of the rod part 32 entering the guide sleeve is not less than 80.00mm, so that the problem that the screw is easy to slip off the screwdriver head or deviate from the screw when the screwdriver 3 is used can be effectively solved. Meanwhile, the handle 31 with knurling and long enough can solve the problem that the screw is difficult to mount and dismount due to insufficient torque. The size of the internal thread of the guide sleeve 2 is matched with that of the counterweight screw, the length of the internal thread is 3.00-8.00 mm, the screwing direction of the thread is right-handed, namely the first direction, and the whole length of the guide sleeve 2 is 100.00 mm.

In order to improve the production efficiency of the device and save the cost, in one embodiment, the guiding sleeve 2 comprises a first cylinder 21 provided with a third thread 23 and a second cylinder 22 connected with the first cylinder 21, wherein the inner diameter of the first cylinder 21 is larger than that of the second cylinder 22, and at least one set of the third thread 23 is arranged on the inner wall surface in the first cylinder 21. The first barrel 21 being larger than the second barrel 22 facilitates the provision of the third thread 23, while multiple sets of the third thread 23 may be suitable for different sizes of fasteners 1. In other embodiments, the first cylinder 21 has a length of 10mm and an outer diameter of 10mmThe outer diameter of the second cylinder of the guide sleeve 2 isThe design scheme that the front section of the guide sleeve is thick and the rear end of the guide sleeve is thin relative to the fastener can ensure that the front end of the guide sleeve 2 can be processed into a large enough internal thread, so that a large-size screw can be assembled into the guide sleeve; the thin rear end of the guide sleeve enables the guide sleeve to be flexibly operated in a limited moving space formed by two adjacent layers of blade teeth of the impeller.

In order to improve the applicability of the device, which is suitable for assembling fasteners 1 with various sizes, in one embodiment, the sizes of the third threads 23 arranged on the inner wall surface of the first cylinder 21 are different, so that the cross section of the first cylinder 21 has a step structure, and the whole cross section is horn-shaped. The third threads 23 of different sizes correspond to fasteners 1 of different outer diameters, improving the applicability of the product.

In order to improve the assembly efficiency, in one embodiment the length of the guide sleeve 2 is smaller than the overall length of the screwdriver 3. The design scheme is convenient for users to operate.

In order to improve the portability of the product, in one embodiment, the guiding sleeve 2 and the screwdriver 3 are of a split structure.

In order to improve the product suitability, in addition to the solution by providing different sized third threads 23 on the same guiding sleeve 2, in one embodiment the means for precision structure assembly comprises one screwdriver 3 and a plurality of guiding sleeves 2 cooperating with the screwdriver 3, wherein the plurality of guiding sleeves 2 are provided with different sized third threads 23. In a kit, the screwdriver 3 can be used with a plurality of guide sleeves 2, each guide sleeve 2 corresponding to a different size of fastener 1.

To improve the guiding action of the guiding sleeve 2, in one embodiment the length of the third thread 23 is not less than one third of the overall length of the fastener 1.

As shown in fig. 4-5, in one embodiment, the precision structure assembly is a counterweight assembly of a molecular pump, the fastener 1 is a counterweight screw, and the mounting hole is a counterweight hole 4 disposed on an impeller of a turbine of the molecular pump. The balance weight screw has the same overall outer diameter as the fastener 1 used in the present application, and therefore, a device for precision structural assembly can be considered to realize the balance weight of the molecular pump. Considering that the balance weight screw is loosened or moved in the balance weight port during the operation of the molecular pump due to the fact that the overall outer diameter of the balance weight screw is equal, in one embodiment, an included angle alpha is formed between the central axis of the balance weight port 4 and the center of the turbine, and is more than or equal to 60 degrees and less than or equal to 90 degrees.

Exemplary method

The turbo molecular pump is a vacuum pump which utilizes a turbine rotor rotating at high speed to transmit kinetic energy to gas molecules so as to enable the gas molecules to obtain directional speed, and then the gas molecules are compressed and driven to an exhaust port and pumped away by a backing pump. The magnetic suspension molecular pump adopts a magnetic bearing to replace a traditional mechanical bearing and is used as a support mode of a turbine rotor of the turbo molecular pump, the rotor is stably suspended in the air during working, and the turbine rotor can stably work at the rotating speed of tens of thousands of revolutions per minute due to no mechanical contact. In a rotary machine, rotor vibration is a main factor that restricts rotational stability, reliability, life, and the like, and rotor imbalance is the most dominant excitation source of rotor vibration. Therefore, in order to reduce the vibration amount of the turbine rotor in the operation process and prolong the service life of equipment, the dynamic balance test of the turbine molecular pump rotor is an effective means and is also a necessary link in the production, maintenance and repair process of the turbine molecular pump.

Dynamic balancing is a method of reducing the amount of unbalance by measuring the vibration of a rotor, determining the magnitude and location of the unbalance of the rotor with a specific balancing algorithm, and weighting or de-weighting the unbalance at the corresponding locations. The structural design of the rotating parts of some magnetic suspension turbomolecular pumps determines that only the unbalance amount can be reduced by removing the weight on the turbine, but the assembly space of the balance weight on the turbine is limited, and the assembly efficiency of the balance weight is influenced. Therefore, it is necessary to design a method of weighting molecular pumps.

An exemplary embodiment of the present application provides a method for molecular pump weighting as shown in fig. 4, comprising:

fitting one end of the weight screw to the third thread 23 of the guide sleeve 2, wherein the third thread 23 is rotated in the first direction;

the rod part 32 of the screwdriver 3 penetrates into the guide sleeve 2 through the other end of the guide sleeve 2 and is limited together with the top of a counterweight screw assembled on a third thread, and a first thread 41 rotating along a first direction is arranged in the counterweight hole 4;

aligning one end of the counterweight screw, which is far away from the guide sleeve 2, to a counterweight port 4 on the molecular pump;

and rotating the screwdriver 3 along the first direction to enable one end of the counterweight screw to be screwed into the counterweight hole 4 to be matched with the first thread 41 and enable the other end of the counterweight screw to be screwed out in the direction away from the guide cylinder until at least one third of the counterweight screw is screwed into the counterweight hole 4, separating the other end of the counterweight screw from the guide cylinder until the counterweight screw is completely screwed into the counterweight hole 4, and finishing assembly.

When the operation of the molecular pump counterweight is carried out, the required counterweight screw needs to be manually installed on the third thread at one end of the guide sleeve, and the length of the counterweight screw screwed into the third thread is not less than one third of the length of the counterweight screw, so that the assembly firmness between the counterweight screw and the guide sleeve is improved; after the assembly between the counterweight screw and the guide sleeve is completed, the screwdriver enters the guide sleeve from the other end of the guide sleeve, the rod part of the screwdriver is pushed into the straight groove at the end part of the counterweight screw, and the counterweight screw rotates along with the screwdriver; and after the assembly of the screwdriver and the guide sleeve is completed, the counterweight screw on the guide sleeve is aligned with the counterweight hole on the impeller. At this time, the screwdriver is rotated clockwise to rotate the weight screw into the weight port. After the counterweight screws enter the counterweight holes, one hand grips the guide sleeve and the other hand continues to operate the screwdriver. And after all the counterweight screws are screwed out of the guide sleeve, the counterweight screws are screwed into the counterweight holes continuously until the bottoms of the counterweight holes, and the counterweight assembly is completed by screwing.

In the dynamic balance process of the impeller, the hole position of the balance weight adding and reducing screw is far away from the tip end of the blade tooth, and the maximum distance is more than 70.00mm, so that the assembly by using tools such as tweezers or heat shrink tubes is difficult to be in place at one time. However, by adopting the above-mentioned counterweight method for the molecular pump of the application, the counterweight device adopted by the counterweight device plays a role in positioning and guiding the counterweight screw, and can quickly realize the assembly between the counterweight screw and the counterweight holes in different directions and different angles in the counterweight assembly process of the dynamic balance of the molecular pump, thereby solving the problem that the counterweight screw cannot smoothly align to the counterweight holes due to the misalignment of the counterweight screw.

In summary, the present invention provides an apparatus for precision structure assembly and a method for molecular pump balancing, comprising: the device comprises an operating component and a guide component, wherein the operating component can be used for assembling a fastener into a mounting hole in a precision structure, a first thread rotating along a first direction is arranged on the circumferential direction of the inner circumferential wall of the mounting hole, and a second thread matched with the first thread is arranged at one end of the fastener; the guide part is a cavity with openings at two ends and can be sleeved on the periphery of the operation part, and one end of the guide part is provided with a first limiting structure; the first retaining structure may retain the other end of the fastener to the guide member, and the other end of the fastener may be disengaged from the guide member following the assembly of the first and second threads. By using the molecular pump counterweight method of the device, the assembly between the counterweight screws and the counterweight holes in different directions and different angles can be quickly realized in the counterweight assembly process of the dynamic balance of the molecular pump, and the problem that the counterweight screws cannot be smoothly aligned to the counterweight holes due to the misalignment of the counterweight screws is solved. Meanwhile, the device is simple in structure and convenient to operate.

In the description herein, references to the description of the terms "one embodiment," "some embodiments," "an example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Furthermore, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, whereby the features defining "first", "second" may explicitly or implicitly include at least one such feature.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modifications, equivalents and the like that are within the spirit and principle of the present application should be included in the scope of the present application.