CN114135547B - Method for eliminating axial clearance generated by shrinkage in long shaft part cold-assembling process - Google Patents
Method for eliminating axial clearance generated by shrinkage in long shaft part cold-assembling process Download PDFInfo
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- CN114135547B CN114135547B CN202111393648.6A CN202111393648A CN114135547B CN 114135547 B CN114135547 B CN 114135547B CN 202111393648 A CN202111393648 A CN 202111393648A CN 114135547 B CN114135547 B CN 114135547B
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- long shaft
- cold
- piece
- shaft piece
- liquid nitrogen
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- 238000000034 method Methods 0.000 title claims abstract description 26
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 98
- 239000007788 liquid Substances 0.000 claims abstract description 49
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 49
- 230000000694 effects Effects 0.000 claims abstract description 4
- 239000000463 material Substances 0.000 claims description 14
- 238000012856 packing Methods 0.000 claims description 8
- 238000004321 preservation Methods 0.000 claims description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 4
- 238000002791 soaking Methods 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910000831 Steel Inorganic materials 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 229910001369 Brass Inorganic materials 0.000 description 2
- 229910000906 Bronze Inorganic materials 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 2
- 239000010951 brass Substances 0.000 description 2
- 239000010974 bronze Substances 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 2
- 238000005429 filling process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 230000008092 positive effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B4/00—Shrinkage connections, e.g. assembled with the parts at different temperature; Force fits; Non-releasable friction-grip fastenings
- F16B4/006—Shrinkage connections, e.g. assembled with the parts being at different temperature
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Heat Treatment Of Articles (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
The invention discloses a method for eliminating axial clearance generated by shrinkage in the cold-loading process of a long shaft piece, which comprises the steps of firstly, finely requiring the size of a movable piece, reducing the size of an upper end hole of the movable piece, increasing the size of a lower end hole of the movable piece, increasing the chamfer angles of two holes, and cold-loading the long shaft piece into the movable piece from top to bottom; then the lower end of a long shaft piece which is cold-filled into the movable piece is completely immersed into a cold barrel filled with liquid nitrogen, and meanwhile, a weight is additionally arranged at the upper end of the long shaft piece; until the cold barrel filled with liquid nitrogen returns to room temperature. According to the invention, one end of the long shaft piece immersed in liquid nitrogen again still leaves a gap with the hole of the movable piece, the other end of the long shaft piece is expanded first to be in interference fit with the hole wall of the movable piece, after the end immersed in liquid nitrogen is restored to room temperature, the generated interference fit does not have the effect of enabling the long shaft piece to generate axial movement, so that the axial gap generated in the process of restoring cold load to normal temperature is eliminated, and the cold load quality and the integral assembly efficiency are ensured.
Description
Technical Field
The invention belongs to the technical field of long shaft piece cold-filling, and particularly relates to a method for eliminating axial gaps generated by shrinkage in the long shaft piece cold-filling process.
Background
In the heavy machinery assembly, the shaft part with the diameter of more than 150mm and the length of more than 1.5m is cold-assembled, and the existing method only comprises the step of immersing the shaft to be assembled by liquid nitrogen to reduce the diameter of the shaft, so that the assembly gap between the shaft and the hole is formed, and the aim of cold-assembling is fulfilled. However, this method causes axial play due to expansion during the recovery of the shaft from the low temperature state to the normal temperature, resulting in axial play between the shaft and the assembled movable member.
Disclosure of Invention
The invention provides a method for eliminating axial clearance generated by shrinkage in the cold-loading process of long shaft parts, which can not only effectively reduce the axial clearance generated by expansion after cold-loading, but also avoid repair work generated by the clearance, improve the overall efficiency and ensure the service life and quality of machinery.
The invention is realized in such a way that the axial clearance generated by shrinkage in the cold-mounting process of the long shaft piece is eliminated, and the long shaft piece is firstly cold-mounted into the movable piece from top to bottom; then the lower end of the long shaft piece which is cold-filled into the movable piece is completely immersed into a cold barrel filled with liquid nitrogen, and meanwhile, a weight is additionally arranged at the upper end of the long shaft piece to prevent the axial movement of the long shaft piece; until the cold barrel filled with liquid nitrogen returns to room temperature.
In the above technical solution, preferably, the hole at the upper end of the movable member is processed to a lower difference of-0.21, the hole at the lower end is processed to an upper difference of the required size, and the upper difference is +0.16; the chamfer angles of the holes at the upper end and the lower end are 16-19 multiplied by 45 degrees.
In the above technical scheme, preferably, the long shaft member is cold-packed into the movable member by soaking the long shaft member in liquid nitrogen to a required temperature and preserving heat for a certain time, and then rapidly cold-packing.
In the above technical solution, it is further preferable that the temperature required for cold-filling the long shaft member is calculated by the following formula (1):
T＝2i/dα (1)
wherein: t is the temperature required by cold-packing of the long shaft piece, and is at the temperature of DEG C; alpha is the linear expansion coefficient of the long shaft piece; i is the maximum interference of the movable piece, mm; d is the matching diameter of the movable part and mm.
The heat preservation time required by cold-filling of the long shaft piece is calculated by adopting the following formula (2):
t＝aδ+6 (2)
wherein: t is the heat preservation time required by cold-packing of the long shaft piece, and min; a is the integral coefficient related to the material of the long shaft piece; delta is the maximum cooling wall thickness of the long shaft piece and mm.
The liquid nitrogen amount required by cold filling of the long shaft piece is calculated by adopting the following formula (3):
P＝2G+b (3)
wherein: p is the liquid nitrogen quantity required by cold filling of the long shaft piece, kg; g is the weight of the long shaft piece, kg; b is the amount of liquid nitrogen consumed in a cold-packed container or the like, which is not easy to calculate, and (1/3-1/2) G and kg are generally taken.
In the above technical scheme, preferably, the material of cold barreled is copper inner core iron sheet outer wall, and the evacuation is done to the centre, can realize the heat preservation function and can deposit liquid nitrogen and not damage.
In the above technical scheme, preferably, the amount of liquid nitrogen filled in the cold filling barrel is controlled by a liquid nitrogen vehicle valve.
In the above technical solution, preferably, the weight is a regular weight of 2 tons to 5 tons.
The invention has the advantages and positive effects that:
according to the invention, the size of the upper end hole of the movable piece with the axial gap is reduced by refining the size of the movable piece, the size of the lower end hole of the movable piece is increased, and the chamfer angles of the two holes are increased; the shaft end exposed out of the long shaft piece which is cold-filled into the movable piece is completely immersed into the cold-filling barrel filled with liquid nitrogen, meanwhile, the other end of the long shaft piece is additionally provided with a heavy object to prevent the axial movement of the long shaft piece until the cold-filling barrel filled with liquid nitrogen returns to the room temperature, so that one end of the long shaft piece which is immersed into liquid nitrogen again leaves a gap with a hole of the movable piece, the other end of the long shaft piece is expanded first to be in interference fit with the hole wall of the movable piece, and after one end immersed into liquid nitrogen returns to the room temperature, the generated interference fit does not have the effect of enabling the long shaft piece to generate the axial movement, so that the axial gap generated in the process of cold-filling returning to the room temperature is eliminated, and the cold-filling quality and the whole assembly efficiency are ensured.
Drawings
Fig. 1 is a schematic structural view of a cold pack according to an embodiment of the present invention.
In the figure: 1. a weight; 2. a long shaft member; 3. a movable member; 4. and (5) cold barreling.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Examples
Referring to fig. 1, the present embodiment provides a method for eliminating axial gaps generated by shrinkage of a long shaft member during cold-assembling, wherein the long shaft member 2 is cold-assembled into a movable member 3 from top to bottom; then the lower end of the long shaft piece 2 which is cold-filled into the movable piece 3 is completely immersed into a cold-filling barrel 4 filled with liquid nitrogen, and meanwhile, the upper end of the long shaft piece 2 is additionally provided with a weight 1 for preventing the axial movement of the long shaft piece 2; until the cold barrel 4 filled with liquid nitrogen returns to room temperature.
The hole at the upper end of the movable piece 3 is processed to a lower difference of-0.21, the hole at the lower end is processed to an upper difference of the required size, and the upper difference is +0.16; the chamfer angles of the holes at the upper end and the lower end are 16-19 multiplied by 45 degrees.
The long shaft piece 2 is cold-packed into the movable piece 3 by soaking the long shaft piece 2 to the required temperature through liquid nitrogen and preserving heat for a certain time, and then rapidly cold-packing.
The temperature required by cold-filling the long shaft piece 2 is calculated by adopting the following formula (1):
T＝2i/dα (1)
wherein: t is the temperature required by cold-packing of the long shaft piece 2, and is at the temperature of DEG C; alpha is the linear expansion coefficient of the long shaft member 2; i is the maximum interference of the movable piece 3, mm; d is the matching diameter of the movable part 3, and mm. The linear expansion coefficient α was 0.000016 when the material of the long shaft member 2 was brass, 0.000015 when the material was bronze, 0.0000085 when the material was steel, and 0.000008 when the material was cast iron.
The heat preservation time required by cold-filling of the long shaft piece 2 is calculated by adopting the following formula (2):
t＝aδ+6 (2)
wherein: t is the heat preservation time required by cold-packing of the long shaft piece 2, and min; a is the comprehensive coefficient related to the material of the long shaft piece 2; delta is the maximum cooling wall thickness of the long shaft piece 2 and mm. When the material of the long shaft member 2 is brass, the overall coefficient a is 0.8, when the material is bronze, the overall coefficient a is 0.9, when the material is steel, the overall coefficient a is 1.2, and when the material is cast iron, the overall coefficient a is 1.3.
The liquid nitrogen amount required by cold filling of the long shaft piece 2 is calculated by the following formula (3):
P＝2G+b (3)
wherein: p is the liquid nitrogen quantity required by cold filling of the long shaft piece 2, kg; g is the weight of the long shaft piece 2 and kg; b is the amount of liquid nitrogen consumed in a cold-packed container or the like, which is not easy to calculate, and (1/3-1/2) G and kg are generally taken.
The cold filling barrel 4 is made of copper inner core iron sheet outer wall, and the middle is vacuumized, so that the heat preservation function can be realized, and liquid nitrogen can be stored without damage.
The amount of liquid nitrogen filled in the cold filling barrel 4 is controlled by a liquid nitrogen vehicle valve.
The weight 1 is a regular weight of 2 tons to 5 tons.
The invention takes a long shaft piece 2 with the shaft length of 2.8m and the diameter of 323mm in a 2300 winding drum as an example to illustrate the cold-filling process, and specifically comprises the following steps:
firstly, processing the hole at the upper end of the movable piece 3 to a lower difference of required size, wherein the lower difference is-0.21, the hole at the upper end is phi 317mm, the hole at the lower end of the movable piece 3 is processed to an upper difference of required size, the upper difference is +0.16, and the hole at the lower end is phi 323mm; and the chamfer angles of the holes at the upper end and the lower end are increased to be 17 multiplied by 45 degrees.
The linear expansion coefficient alpha of the long shaft piece 2 is 0.0000085, and the maximum interference i of the movable piece 3 is 0.8mm; the matching diameter d of the movable piece 3 is 323mm; the material of the long shaft piece 2 is steel, and the comprehensive coefficient a related to the material of the long shaft piece 2 is 1.2; the maximum cooling wall thickness delta of the long shaft piece 2 is 323mm, and the weight of the long shaft piece 2 is 1600 kg; the temperature required by the long shaft piece 2 for cold filling is calculated to be-200 ℃ according to the formula (1), the heat preservation time required by the long shaft piece 2 for cold filling is calculated to be 426min according to the formula (2), and the liquid nitrogen amount required by the long shaft piece 2 for cold filling is calculated to be 3800kg according to the formula (3).
Soaking the long shaft piece 2 to about-200 ℃ through liquid nitrogen, preserving heat for 400-450min, quickly filling the long shaft piece 2 into the movable piece 3, adding a cold filling barrel 4 filled with liquid nitrogen at the exposed shaft end at the lower end of the long shaft piece 2, and controlling the liquid nitrogen amount through a liquid nitrogen vehicle valve to enable the shaft end to be completely immersed into the liquid nitrogen; meanwhile, a 2 ton standard block weight 1 is additionally arranged at the upper end of the long shaft piece 2 to prevent the axial movement of the long shaft piece 2 until the cold barrel 4 filled with liquid nitrogen returns to room temperature.
In summary, the present invention reduces the size of the hole at the upper end of the movable member 3 (to the lower dimension of the drawing), which generates the axial gap, by refining the hole at the upper and lower ends of the movable member 3, thereby increasing the size of the hole at the lower end of the movable member 3 (to the upper dimension of the drawing), and increasing the chamfer angles of the two holes; the exposed shaft end of the long shaft piece 2 which is cold-filled into the movable piece 3 is completely immersed into the cold-filling barrel 4 filled with liquid nitrogen, meanwhile, the weight 1 is additionally arranged at the other end of the long shaft piece 2 to prevent the axial movement of the long shaft piece 2 until the cold-filling barrel 4 filled with liquid nitrogen returns to room temperature, so that one end of the long shaft piece 2 which is immersed again into liquid nitrogen still leaves a gap with a hole at the lower end of the movable piece 3, the other end of the long shaft piece is expanded for interference fit with the hole wall at the upper end of the movable piece 3, after the end immersed into liquid nitrogen returns to room temperature, the generated interference fit does not have the effect of enabling the long shaft piece 2 to generate axial movement, the axial gap generated in the process of cold-filling to room temperature is eliminated, and the cold-filling quality and the assembly attractiveness are ensured.
The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the invention in any way, but any simple modification, equivalent variation and modification of the above embodiments according to the technical principles of the present invention are within the scope of the technical solutions of the present invention.
Claims (7)
1. A method for eliminating axial clearance generated by shrinkage in the cold-mounting process of a long shaft piece is characterized in that the long shaft piece is firstly cold-mounted into a movable piece from top to bottom; then the lower end of the long shaft piece which is cold-filled into the movable piece is completely immersed into a cold barrel filled with liquid nitrogen, and meanwhile, a weight is additionally arranged at the upper end of the long shaft piece to prevent the axial movement of the long shaft piece; until the cold barrel filled with liquid nitrogen returns to room temperature;
the long shaft piece is cold-installed into the movable piece by soaking the long shaft piece to a required temperature through liquid nitrogen and preserving heat for a certain time, and then rapidly cold-installing;
the liquid nitrogen amount required by cold filling of the long shaft piece is calculated by adopting the following formula (3):
P=2G+b（3）
wherein: p is the liquid nitrogen quantity required by cold filling of the long shaft piece, kg; g is the weight of the long shaft piece, kg; b is the liquid nitrogen amount consumed in cold-packed containers and the like and is not easy to calculate, and (1/3-1/2) G and kg are generally taken;
the long shaft piece is immersed in the liquid nitrogen again, one end of the long shaft piece still leaves a gap with the hole at the lower end of the movable piece, the other end of the long shaft piece is expanded first to be in interference fit with the hole wall at the upper end of the movable piece, after the end immersed in the liquid nitrogen is restored to room temperature, the generated interference fit does not have the effect of enabling the long shaft piece to axially float, and the axial gap generated in the process of restoring cold packs to normal temperature is eliminated.
2. The method for eliminating axial clearance caused by shrinkage during cold-fitting of long shaft parts according to claim 1, wherein the holes at the upper end of the movable part are processed to a lower difference of required size, the lower difference is-0.21, the holes at the lower end are processed to an upper difference of required size, and the upper difference is +0.16; the chamfer angles of the holes at the upper end and the lower end are 16-19 multiplied by 45 degrees.
3. The method for eliminating axial gap generated by shrinkage during cold-filling of long shaft parts according to claim 1, wherein the temperature required for cold-filling of the long shaft parts is calculated by the following formula (1):
T=2i/dα （1）
wherein: t is the temperature required by cold-packing of the long shaft piece, and is at the temperature of DEG C; alpha is the linear expansion coefficient of the long shaft piece; i is the maximum interference of the movable piece, mm; d is the matching diameter of the movable part and mm.
4. The method for eliminating axial clearance caused by shrinkage during cold-filling of long shaft members according to claim 1, wherein the heat-retaining time required for cold-filling of the long shaft members is calculated by the following formula (2):
t=aδ+6（2）
wherein: t is the heat preservation time required by cold-packing of the long shaft piece, and min; a is the integral coefficient related to the material of the long shaft piece; delta is the maximum cooling wall thickness of the long shaft piece and mm.
5. The method for eliminating axial gaps generated by shrinkage in the cold-assembling process of long shaft parts according to claim 1, wherein the cold-assembling barrel is made of an outer wall of a copper core iron sheet, and the middle is vacuumized, so that the heat-insulating function can be realized, and liquid nitrogen can be stored without damage.
6. The method of eliminating shrinkage from an axial gap during cold filling of long shaft members according to claim 1, wherein the amount of liquid nitrogen filled in the cold filling barrel is controlled by a valve of a liquid nitrogen vehicle.
7. The method of eliminating shrinkage from axial play during cold-filling of long shaft members as defined in claim 1, wherein said weight is a regular weight of 2 ton to 5 ton.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111393648.6A CN114135547B (en) | 2021-11-23 | 2021-11-23 | Method for eliminating axial clearance generated by shrinkage in long shaft part cold-assembling process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111393648.6A CN114135547B (en) | 2021-11-23 | 2021-11-23 | Method for eliminating axial clearance generated by shrinkage in long shaft part cold-assembling process |
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| Publication Number | Publication Date |
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| CN114135547A CN114135547A (en) | 2022-03-04 |
| CN114135547B true CN114135547B (en) | 2024-04-12 |
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101134280A (en) * | 2007-09-26 | 2008-03-05 | 中国北车集团北京二七机车厂有限责任公司 | Device for assembling and disassembling gas valve seat on the cylinder cap |
| CN103551797A (en) * | 2013-10-10 | 2014-02-05 | 车晋绥 | Red-hot iron heating method of small-sized gear internal hole |
| CN203822683U (en) * | 2014-05-12 | 2014-09-10 | Tcl瑞智（惠州）制冷设备有限公司 | Assembly structure for shaft and rotor of compressor |
| CN204471233U (en) * | 2014-12-25 | 2015-07-15 | 天津华建天恒传动有限责任公司 | Heavy pin shaft positioner |
| CN205496905U (en) * | 2016-04-20 | 2016-08-24 | 山东博特精工股份有限公司 | Special frock of cold charge thin wall copper sheathing |
| CN107407316A (en) * | 2014-09-30 | 2017-11-28 | Lisi航空 | By the fastener for lubricating interference fit |
| CN109693071A (en) * | 2018-12-27 | 2019-04-30 | 苏州海陆重工股份有限公司 | For taking over and the adapter tube cold joint technique of aperture interference fit |
| CN109723704A (en) * | 2019-01-17 | 2019-05-07 | 中国工程物理研究院机械制造工艺研究所 | A kind of memorial alloy interference connector and preparation method thereof |
| JP2020029609A (en) * | 2018-08-24 | 2020-02-27 | 株式会社神戸製鋼所 | Treatment method for improving fretting fatigue strength |
| CN113385885A (en) * | 2021-05-20 | 2021-09-14 | 中国电子科技集团公司第十四研究所 | Device for intelligently monitoring interference assembly of rotary table in real time and assembly method |
-
2021
- 2021-11-23 CN CN202111393648.6A patent/CN114135547B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101134280A (en) * | 2007-09-26 | 2008-03-05 | 中国北车集团北京二七机车厂有限责任公司 | Device for assembling and disassembling gas valve seat on the cylinder cap |
| CN103551797A (en) * | 2013-10-10 | 2014-02-05 | 车晋绥 | Red-hot iron heating method of small-sized gear internal hole |
| CN203822683U (en) * | 2014-05-12 | 2014-09-10 | Tcl瑞智（惠州）制冷设备有限公司 | Assembly structure for shaft and rotor of compressor |
| CN107407316A (en) * | 2014-09-30 | 2017-11-28 | Lisi航空 | By the fastener for lubricating interference fit |
| CN204471233U (en) * | 2014-12-25 | 2015-07-15 | 天津华建天恒传动有限责任公司 | Heavy pin shaft positioner |
| CN205496905U (en) * | 2016-04-20 | 2016-08-24 | 山东博特精工股份有限公司 | Special frock of cold charge thin wall copper sheathing |
| JP2020029609A (en) * | 2018-08-24 | 2020-02-27 | 株式会社神戸製鋼所 | Treatment method for improving fretting fatigue strength |
| CN109693071A (en) * | 2018-12-27 | 2019-04-30 | 苏州海陆重工股份有限公司 | For taking over and the adapter tube cold joint technique of aperture interference fit |
| CN109723704A (en) * | 2019-01-17 | 2019-05-07 | 中国工程物理研究院机械制造工艺研究所 | A kind of memorial alloy interference connector and preparation method thereof |
| CN113385885A (en) * | 2021-05-20 | 2021-09-14 | 中国电子科技集团公司第十四研究所 | Device for intelligently monitoring interference assembly of rotary table in real time and assembly method |
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| CN114135547A (en) | 2022-03-04 |
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