CN103419100A - Bearing outer ring grinding process - Google Patents
Bearing outer ring grinding process Download PDFInfo
- Publication number
- CN103419100A CN103419100A CN2013102483204A CN201310248320A CN103419100A CN 103419100 A CN103419100 A CN 103419100A CN 2013102483204 A CN2013102483204 A CN 2013102483204A CN 201310248320 A CN201310248320 A CN 201310248320A CN 103419100 A CN103419100 A CN 103419100A
- Authority
- CN
- China
- Prior art keywords
- outer ring
- bearing outer
- bearing
- grinding
- grinding process
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Rolling Contact Bearings (AREA)
- Grinding Of Cylindrical And Plane Surfaces (AREA)
Abstract
The invention relates to a bearing outer ring grinding process and solves the problems that appearance is influenced due to the fact that processing prints are unavoidably left on an outer ring of a bearing and the outer ring needs to be ground for many times during processing of a grooved way of the bearing when the circular center of the groove way of the bearing deviates from the circular center of the outer diameter of the bearing in the prior art of processing of the outer ring. The bearing outer ring grinding process is characterized by including the following steps: grinding the outer ring of the bearing for three times, directly grinding the outer ring to be in a final size, and adopting ceramic support for grinding of the grooved way of the outer ring of the bearing. The grooved way and the outer diameter are good in concentricity, process turnover is reduced, production efficiency of the outer ring is improved, grinding time and processing cost are reduced, wall thickness difference is high in controllability, and roundness accuracy of the grooved way of the outer ring is greatly improved.
Description
Technical field
The present invention relates to bearing manufacturing technology field, especially a kind of bearing outer ring grinding process.
Background technology
Bearing top circle centerless grinding is one of bearing outer ring processing method commonly used, and for medium and small model bearing, application also the most extensively, processing effect is also better.In bearing top circle centreless grinding process, the center of circle of bearing can't determine, so grinding of bearing outer ring channel needs to carry out the centerless grinding of external diameter after cutting again, and will cause like this bearing channel center of circle deviation to occur with the center of circle of bearing external diameter.And, in conventional bearing outer ring groove processing technique, also inevitably on bearing top circle, stay the processing marking, affect outward appearance.As the outer ring processing method that patent publication No. is the disclosed a kind of light and narrow series precision corner contact ball bearing of CN102996649A, manufacturing procedure is to grind the corase grind end face-outer internal diameter of corase grind external diameter-mill-corase grind outer fissure-corase grind fore shaft-additional tempering-whole face grinding-lappingout end face-fine grinding external diameter-end to grind fore shaft-end to grind raceway groove-superfinishing raceway groove external diameter-end.
Summary of the invention
The objective of the invention is in order to solve in the processing of existing outer ring, the bearing channel center of circle deviation occurs with the bearing external diameter center of circle, bearing channel adds man-hour, inevitably on bearing top circle, stay the processing marking, affect outward appearance, and cylindrical needs the repeatedly problem of grinding, provide a kind of technological design reasonable, utilize guide plate, ceramic support to be led, without the bearing outer ring grinding process that carries out again grinding after the bearing outer ring moulding.
Above-mentioned technical problem of the present invention is mainly solved by following technical proposals: a kind of bearing outer ring grinding process is characterized in that having following steps:
(1) prepare blank; (2) heat treatment; (3) mill Double End; (4) bearing top circle grinding; Cylindrical divides 3 grindings: at first remove the external diameter casting skin, stock removal 0.08～0.12mm; Then roughly grind external diameter, stock removal 0.10～0.15mm; Last fine grinding bearing outside diameter, stock removal 0.035～0.04mm; (5) grinding of bearing outer ring channel is cut, and adopts ceramic support, ceramic support width=bearing outer ring nominal height-2* bearing outer ring maximum axial chamfering length-(0.2～0.4) mm; (6) bearing outer ring channel superfine milling.
The main distinction of the technical program and conventional machining mode is aspect bearing top circle grinding and grinding of bearing outer ring channel cut, when the bearing outside diameter grinding, by 3 times continuous grindings, directly be ground to the final size of bearing outside diameter, take external diameter as benchmark during because of the outer ring raceway grinding, as long as avoid the raceway groove grinding to the surface, outer ring, not bring bad result, it is exactly priority scheme, the design of ceramic supporting element has reached this requirement, like this, external diameter does not afterwards just need to carry out grinding again, and the concentricity of raceway groove and external diameter is more perfect.The outer ring engineering height of the guiding width of ceramic supporting element and processed bearing has close position relationship.
As preferably, described workpiece, the guide wheel line of centres and guide wheel, emery wheel line of centres angle are 4～8 degree, and workpiece, the emery wheel line of centres and guide wheel, emery wheel line of centres angle are 6～10 to spend.Best angle design between workpiece, guide wheel, emery wheel three, make workpiece stressed and stable state in the best in process.The technical program especially is applicable to external diameter 100～150mm bearing machining, and now, establishing the work piece centre-height is 13.5～19.7mm, and emery wheel is 12～16.7mm with respect to the displacement of workpiece.
As preferably, described ceramic support adopts zirconia ceramics to support; The ceramic support surface roughness is Ra0.19～0.23 μ m.Aspect structural ceramics, zirconia ceramics has high tenacity, high-flexural strength and high-wearing feature, and excellent heat-proof quality, and thermal coefficient of expansion is close to advantages such as steel; Aspect function ceramics, zirconia ceramics has excellent resistance to elevated temperatures.Best surface roughness design avoids ceramic support to produce vestige to bearing top circle.
As preferably, described grinding of bearing outer ring channel is cut, and adopts 120 order vitrified bonding emery wheels, and corase grind speed is 8～12 μ m/s, determines journey 0.30～0.35mm, and fine grinding speed is 3～5 μ m/s, determines journey 0.03～0.05mm.Adopt the technical program, bearing outer ring channel is also a continuous process, and its basis, location is constant, the concentricity with assurance with bearing outside diameter.
As preferably, described bearing top circle grinding is provided with guide plate below bearing outer ring.Guide plate and guide wheel form lower support and the location of bearing outer ring jointly.
As preferably, described guide plate has the height point on the inclined-plane ，Gai inclined-plane tangent with bearing outer ring towards the bearing outer ring screw-in direction, and the low spot on this inclined-plane screws out direction towards bearing outer ring.The horizontal plane that the inclined-plane of guide plate and emery wheel, guide wheel center line form at angle, and supported by the maximum weighted position during just to the bearing outer ring grinding.
Effective effect of the present invention is:
1. during due to the bearing outside diameter grinding, directly be ground to final size, take external diameter during the outer ring raceway grinding as benchmark, external diameter no longer carries out grinding, raceway groove and external diameter good concentricity afterwards.
2. by the technical program, reduce external diameter mill manufacturing procedure at least one times, reduced the operation turnover, improved outer ring production efficiency, reduced grinding time and processing cost.
3. outer ring raceway and external diameter good concentricity not only, the Wall-Thickness Difference controllability is strong, and outer ring raceway circularity precision improves greatly.
4. the raising of Product Precision, extended service life of bearing.
The accompanying drawing explanation
Fig. 1 is a kind of cylindricalo grinding status architecture schematic diagram of the present invention.
Fig. 2 is that a kind of grinding of bearing outer ring channel of the present invention is while cutting and the relational structure schematic diagram of Support Position.
In figure: 1. emery wheel, 2. bearing outer ring, 3. guide wheel, 4. guide plate, 5. ceramic support.
The specific embodiment
Below by embodiment, and by reference to the accompanying drawings, technical scheme of the present invention is described in further detail.
A kind of bearing outer ring grinding process of the present embodiment, the bearing that the external diameter of take is 100mm is example, makes according to the following steps:
One, prepare blank.
Two, heat treatment.Quenching, tempering, Bainitic hardening, 820～830 ℃ of hardening heats, 180 ± 5 ℃ of tempering after salt hardening.
Three, processing mode grinds Double End routinely.
Four, bearing top circle grinding.As shown in Figure 1, the high 13.5mm that is made as of workpiece centre, emery wheel is 12mm with respect to the displacement of bearing outer ring, and bearing outer ring workpiece, the guide wheel line of centres and guide wheel, emery wheel line of centres angle are 8 degree, and bearing outer ring workpiece, the emery wheel line of centres and guide wheel, emery wheel line of centres angle are 6 degree.During grinding, be provided with guide plate below bearing outer ring, guide plate has the inclined-plane tangent with bearing outer ring, the height point on this inclined-plane is towards the bearing outer ring screw-in direction, the low spot on inclined-plane screws out direction towards bearing outer ring, figure middle (center) bearing outer ring is rotated counterclockwise, and guide plate is positioned at take the third quadrant of the coordinate seat that the bearing outer ring center is round dot.Cylindrical divides and carries out grinding 3 times: the first step is used the A60J emery wheel to remove the external diameter casting skin, stock removal 0.08～0.12mm; A80J emery wheel corase grind external diameter for second step, stock removal 0.10～0.15mm; The 3rd step is used A100J emery wheel fine grinding bearing outside diameter, stock removal 0.035～0.04mm.
Five, grinding of bearing outer ring channel is cut.The employing zirconia ceramics supports.
The length of ceramic support (L)=bearing outer ring nominal height (H)-2* bearing outer ring maximum axial chamfering length-(0.2～0.4) mm, as shown in Figure 2.
The ceramic support surface roughness is Ra0.19 μ m.Adopt 120 order vitrified bonding emery wheels, corase grind speed is 10 μ m/s, determines journey 0.30mm, and fine grinding speed is 4 μ m/s, determines journey 0.04mm.
Six, carry out the bearing outer ring channel superfine milling.
By the processing of the technical program, the concentricity of bearing outer ring channel and external diameter is better, and within Wall-Thickness Difference can be controlled in 2 μ m, the circularity of bearing outer ring channel is within 1.2 μ m, more than running accuracy all can be controlled in the P5 grade.Outer ring production efficiency approximately 20% be can improve, mill process time and processing cost reduced.
Above-described embodiment is to explanation of the present invention, is not limitation of the invention, any structure after simple transformation of the present invention, method is all belonged to protection scope of the present invention.
Claims (6)
1. a bearing outer ring grinding process is characterized in that having following steps:
(1) prepare blank;
(2) heat treatment;
(3) mill Double End;
(4) bearing top circle grinding; Cylindrical divides 3 grindings: at first remove the external diameter casting skin, stock removal 0.08～0.12mm; Then roughly grind external diameter, stock removal 0.10～0.15mm; Last fine grinding bearing outside diameter, stock removal 0.035～0.04mm;
(5) grinding of bearing outer ring channel is cut, and adopts ceramic support, ceramic support width=bearing outer ring nominal height-2* bearing outer ring maximum axial chamfering length-(0.2～0.4) mm;
(6) bearing outer ring channel superfine milling.
2. a kind of bearing outer ring grinding process according to claim 1, is characterized in that, workpiece, the guide wheel line of centres and guide wheel, emery wheel line of centres angle are 4～8 degree, and workpiece, the emery wheel line of centres and guide wheel, emery wheel line of centres angle are 6～10 degree.
3. a kind of bearing outer ring grinding process according to claim 1 and 2, is characterized in that described ceramic support adopts zirconia ceramics to support; The ceramic support surface roughness is Ra0.19～0.23 μ m.
4. a kind of bearing outer ring grinding process according to claim 1 and 2, is characterized in that, grinding of bearing outer ring channel is cut, adopt 120 order vitrified bonding emery wheels, corase grind speed is 8～12 μ m/s, determines journey 0.30～0.35mm, fine grinding speed is 3～5 μ m/s, determines journey 0.03～0.05mm.
5. a kind of bearing outer ring grinding process according to claim 1 and 2, is characterized in that, described bearing top circle grinding is provided with guide plate below bearing outer ring.
6. a kind of bearing outer ring grinding process according to claim 5, is characterized in that, described guide plate has the height point on the inclined-plane ，Gai inclined-plane tangent with bearing outer ring towards the bearing outer ring screw-in direction, and the low spot on this inclined-plane screws out direction towards bearing outer ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310248320.4A CN103419100B (en) | 2013-06-21 | 2013-06-21 | A kind of bearing outer ring grinding process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310248320.4A CN103419100B (en) | 2013-06-21 | 2013-06-21 | A kind of bearing outer ring grinding process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103419100A true CN103419100A (en) | 2013-12-04 |
| CN103419100B CN103419100B (en) | 2015-09-16 |
Family
ID=49644740
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310248320.4A Active CN103419100B (en) | 2013-06-21 | 2013-06-21 | A kind of bearing outer ring grinding process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103419100B (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103692302A (en) * | 2013-12-23 | 2014-04-02 | 河南金鑫精密轴承制造有限公司 | Precision angular contact ball bearing excircle grinding process |
| CN103753359A (en) * | 2013-12-16 | 2014-04-30 | 海宁奇晟轴承有限公司 | Outer peripheral face polishing machine for bearing outer ring |
| CN105003544A (en) * | 2015-07-22 | 2015-10-28 | 如皋市非标轴承有限公司 | Novel sealed bearing and manufacturing method thereof |
| CN106041651A (en) * | 2015-04-02 | 2016-10-26 | 马勒国际有限公司 | Grinding machine |
| CN106493614A (en) * | 2016-11-14 | 2017-03-15 | 海瑞恩精密技术（太仓）有限公司 | A kind of milling drum and its using method |
| CN108581641A (en) * | 2018-04-12 | 2018-09-28 | 常熟市创新陶瓷有限公司 | A kind of grinding process pumping high-accuracy Ceramic shaft sleeve |
| CN109605177A (en) * | 2018-12-11 | 2019-04-12 | 贵州天马虹山轴承有限公司 | A kind of processing technology controlling bearing inside/outside lasso ball race grinding stress |
| CN110355627A (en) * | 2019-06-18 | 2019-10-22 | 无锡诚石轴承有限公司 | A kind of centreless grinding supporting plate magnetizer |
| CN110449999A (en) * | 2019-08-22 | 2019-11-15 | 朱林辉 | A kind of bearing outer ring manufacture processing method |
| CN110814868A (en) * | 2019-11-30 | 2020-02-21 | 重庆瑞生机械厂有限公司 | High-precision gearbox shaft grinding process |
| CN112296866A (en) * | 2019-08-02 | 2021-02-02 | 青岛泰德汽车轴承股份有限公司 | Main shaft channel grinding device in shaft-connected bearing |
| CN112720258A (en) * | 2020-12-18 | 2021-04-30 | 象山县三环机电有限公司 | Convenient fixing device for machining and polishing outer ring of hardware bearing |
| CN113601273A (en) * | 2021-07-12 | 2021-11-05 | 无锡诚石轴承有限公司 | Excircle fine super-grinding process method of precision micro-motor bearing |
| CN114310494A (en) * | 2021-12-22 | 2022-04-12 | 中国科学院金属研究所 | Steel bearing ring and preparation method thereof |
| CN114850978A (en) * | 2022-06-16 | 2022-08-05 | 浙江昕兴科技有限公司 | Hub bearing grinding method capable of ensuring inner ring groove position |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112008834A (en) * | 2020-07-16 | 2020-12-01 | 洛阳轴承研究所有限公司 | Production and processing method of ceramic cylindrical roller |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5928065A (en) * | 1998-02-09 | 1999-07-27 | Cummins Engine Company, Inc. | Centerless grinding machine with optimal regulating wheel truing and dressing |
| RU2143966C1 (en) * | 1998-04-09 | 2000-01-10 | Акционерное общество открытого типа "РОЛТОМ" | Method for working races of outer raceways of ball bearings |
| CN1544204A (en) * | 2003-11-21 | 2004-11-10 | 瓦房店轴承集团有限责任公司 | Bearing outside diameter grinding and processing method utilizing noncentral excircle through feed grinding |
| CN101219522A (en) * | 2007-11-30 | 2008-07-16 | 洛阳轴研科技股份有限公司 | Method for abrasively processing flange bearing top circle and end plane |
| CN102756317A (en) * | 2012-07-09 | 2012-10-31 | 大连冶金轴承股份有限公司 | Small-size aligning spherical roller bearing outer ring raceway positioning and abrasive machining device and method |
-
2013
- 2013-06-21 CN CN201310248320.4A patent/CN103419100B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5928065A (en) * | 1998-02-09 | 1999-07-27 | Cummins Engine Company, Inc. | Centerless grinding machine with optimal regulating wheel truing and dressing |
| RU2143966C1 (en) * | 1998-04-09 | 2000-01-10 | Акционерное общество открытого типа "РОЛТОМ" | Method for working races of outer raceways of ball bearings |
| CN1544204A (en) * | 2003-11-21 | 2004-11-10 | 瓦房店轴承集团有限责任公司 | Bearing outside diameter grinding and processing method utilizing noncentral excircle through feed grinding |
| CN101219522A (en) * | 2007-11-30 | 2008-07-16 | 洛阳轴研科技股份有限公司 | Method for abrasively processing flange bearing top circle and end plane |
| CN102756317A (en) * | 2012-07-09 | 2012-10-31 | 大连冶金轴承股份有限公司 | Small-size aligning spherical roller bearing outer ring raceway positioning and abrasive machining device and method |
Non-Patent Citations (1)
| Title |
|---|
| 张洪波: "轴承套圈磨加工工艺过程改进", 《轴承》, no. 12, 5 December 2008 (2008-12-05), pages 19 - 20 * |
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103753359A (en) * | 2013-12-16 | 2014-04-30 | 海宁奇晟轴承有限公司 | Outer peripheral face polishing machine for bearing outer ring |
| CN103753359B (en) * | 2013-12-16 | 2016-07-06 | 海宁奇晟轴承有限公司 | A kind of outer peripheral face polisher of bearing outer ring |
| CN105881122A (en) * | 2013-12-16 | 2016-08-24 | 海宁奇晟轴承有限公司 | Bearing outer ring peripheral surface grinding machine of improved structure |
| CN103692302A (en) * | 2013-12-23 | 2014-04-02 | 河南金鑫精密轴承制造有限公司 | Precision angular contact ball bearing excircle grinding process |
| CN103692302B (en) * | 2013-12-23 | 2016-05-11 | 河南金鑫精密轴承制造有限公司 | Precision corner contact ball bearing peripheral milling processing technology |
| CN106041651A (en) * | 2015-04-02 | 2016-10-26 | 马勒国际有限公司 | Grinding machine |
| CN105003544A (en) * | 2015-07-22 | 2015-10-28 | 如皋市非标轴承有限公司 | Novel sealed bearing and manufacturing method thereof |
| CN106493614A (en) * | 2016-11-14 | 2017-03-15 | 海瑞恩精密技术（太仓）有限公司 | A kind of milling drum and its using method |
| CN108581641A (en) * | 2018-04-12 | 2018-09-28 | 常熟市创新陶瓷有限公司 | A kind of grinding process pumping high-accuracy Ceramic shaft sleeve |
| CN109605177A (en) * | 2018-12-11 | 2019-04-12 | 贵州天马虹山轴承有限公司 | A kind of processing technology controlling bearing inside/outside lasso ball race grinding stress |
| CN110355627A (en) * | 2019-06-18 | 2019-10-22 | 无锡诚石轴承有限公司 | A kind of centreless grinding supporting plate magnetizer |
| CN112296866A (en) * | 2019-08-02 | 2021-02-02 | 青岛泰德汽车轴承股份有限公司 | Main shaft channel grinding device in shaft-connected bearing |
| CN110449999A (en) * | 2019-08-22 | 2019-11-15 | 朱林辉 | A kind of bearing outer ring manufacture processing method |
| CN110814868A (en) * | 2019-11-30 | 2020-02-21 | 重庆瑞生机械厂有限公司 | High-precision gearbox shaft grinding process |
| CN110814868B (en) * | 2019-11-30 | 2021-03-02 | 重庆瑞生机械厂有限公司 | High-precision gearbox shaft grinding process |
| CN112720258A (en) * | 2020-12-18 | 2021-04-30 | 象山县三环机电有限公司 | Convenient fixing device for machining and polishing outer ring of hardware bearing |
| CN113601273A (en) * | 2021-07-12 | 2021-11-05 | 无锡诚石轴承有限公司 | Excircle fine super-grinding process method of precision micro-motor bearing |
| CN114310494A (en) * | 2021-12-22 | 2022-04-12 | 中国科学院金属研究所 | Steel bearing ring and preparation method thereof |
| CN114310494B (en) * | 2021-12-22 | 2023-12-08 | 中国科学院金属研究所 | Steel bearing ring and preparation method thereof |
| CN114850978A (en) * | 2022-06-16 | 2022-08-05 | 浙江昕兴科技有限公司 | Hub bearing grinding method capable of ensuring inner ring groove position |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103419100B (en) | 2015-09-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103419100B (en) | A kind of bearing outer ring grinding process | |
| CN103949851B (en) | A kind of processing method of aluminium alloy thin-walled cylindrical member | |
| CN101224540B (en) | Ball screw processing method | |
| CN110039268B (en) | Processing method of cold-extruded high-wear-resistance bearing outer ring | |
| CN104227345A (en) | Processing method for high-precision thin step shaft and grinding chuck for processing method | |
| CN103273280B (en) | A kind of processing method of special type inspection template | |
| CN103639660A (en) | Machining method of bearing outer ring | |
| CN102267055A (en) | Centre frame of machining cutting machine | |
| CN108673072A (en) | Face-hardened large thin-wall stainless steel axle sleeve manufacturing process | |
| CN109352270B (en) | Male head processing technology | |
| CN104476140A (en) | Turning processing technique for flange of angular contact bearing | |
| CN202985325U (en) | Grinding tool for improving processing precision of deep long through hole | |
| CN101555907B (en) | Ball-type slewing bearing with asymmetric raceway and processing method thereof | |
| CN108568489A (en) | A kind of taper roll bearing outer ring precision cold-rolled manufacturing process | |
| CN104128757A (en) | Lathe spindle machining technology facilitating surface hardenability depth | |
| CN107891320A (en) | A kind of floating support of bearing grinder | |
| CN105081686A (en) | Ball crank processing flow | |
| CN109794626A (en) | A kind of cutter arrangement and method for roughing pulley groove | |
| CN102865304B (en) | Ball type rotary support of composite raceway and machining method of ball type rotary support | |
| CN101804590A (en) | Method for eliminating grinding crack of transition fillet externally connected with shaft shoulder | |
| CN104128753A (en) | Lathe spindle machining technology facilitating machining efficiency and surface quality | |
| CN104440408A (en) | Novel grinding machining method of secondary nozzle-class precision part | |
| CN102554290A (en) | Turning tool and ball screw nut roller path machining method by using same | |
| CN104227354B (en) | The manufacturing process of " the black set of chuck axis " in a kind of high speed winding head | |
| CN114211266A (en) | High-precision thin-wall pipe fitting excircle machining device and machining method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 310022 No. 416 Shiqiao Road, Xiacheng District, Zhejiang, Hangzhou Patentee after: Hangzhou Renben Motor Bearings Co.,Ltd. Patentee after: HANGZHOU BEARING GROUP Co.,Ltd. Address before: 310022 No. 416 Shiqiao Road, Xiacheng District, Zhejiang, Hangzhou Patentee before: HANGZHOU C&U MIDDLE BEARING CO.,LTD. Patentee before: HANGZHOU BEARING GROUP Co.,Ltd. |