A cold rolling equipment and a cold rolling expansion processing technology for sealing the inner ring of a bearing

Abstract

The present invention relates to the field of bearing processing, and specifically discloses a cold rolling device and a cold rolling expansion processing technology for sealing the inner ring of a bearing. The cold rolling device includes a rolling wheel and a core roller. A cold rolling groove is provided on the rolling wheel, and a plurality of feature forming parts are provided on the bottom surface of the cold rolling groove. The feature forming parts are defined to be annularly arranged around the center line of the rolling wheel. The feature forming part includes a groove forming convex part and two forming inclined surfaces. The groove forming convex part is located between the two forming inclined surfaces. The forming inclined surfaces are arranged towards the groove forming convex part and are inclined outwards relative to the groove forming convex part. A positioning groove is provided on the core roller, and the positioning groove is annularly arranged around the center line of the core roller. The above-mentioned cold rolling device realizes the one-time processing and forming of the inner ring of the sealed bearing by reasonably designing the cold rolling groove, which not only effectively guarantees the processing accuracy requirements, but also has the advantages of high production efficiency.

Description

Technical Field

[0001] The present invention relates to the field of bearing processing, and in particular to a cold rolling device and a cold rolling expansion processing technology for sealing the inner ring of a bearing. Background Art

[0002] As an important support and transmission component in the mechanical field, different requirements are put forward for the performance of bearings according to the operating conditions of the bearings. Among them, sealed bearings are common bearing forms and can adapt to various complex working conditions.

[0003] As Figures 1 - 3 shown, the sealed bearing includes an inner ring 01, an outer ring 03, rolling elements, a cage, and a seal cover 02. The seal cover rotates synchronously with the outer ring and slides and seals with the inner ring, which can effectively prevent impurities such as dust and water from entering the rolling element area and extend the service life of the bearing under complex working conditions.

[0004] As Figure 2 and Figure 3 shown for the inner ring of the sealed bearing, a raceway 012 is provided on the outer edge of the inner ring 01, and sealing inclined surfaces 011 are respectively provided on both sides of the raceway 012. The sealing inclined surfaces are inclined inward for sliding contact with the seal cover 02. For the normal operation of the bearing and to achieve a good sealing effect, higher requirements are imposed on the machining accuracy of each feature on the outer edge of the inner ring during machining. For example: the radius of curvature r of the cross-section of the raceway 012, the inclination angle σ of the sealing inclined surface 011, and the positional accuracy of the sealing inclined surface 011 relative to the raceway 012, etc. The positional accuracy of the sealing inclined surface relative to the communication is evaluated by the distance between the radial symmetry plane of the raceway and the lower edge of the sealing inclined surface, that is Figure 2 shown as m and n in

[0005] The transmission machining method for the outer edge surface of the bearing ring is to machine the raceway and the sealing inclined surface in the form of turning after the inner ring is integrally forged. However, it is difficult to effectively guarantee the above accuracy requirements in the turning machining process, and the machining efficiency is relatively low and the production cost is high.

[0006] Another common bearing ring machining process is cold rolling. However, the existing cold rolling expansion processing technology usually can only complete the forming of the raceway, and the machining of the sealing surface on the inner ring of the sealed bearing still needs to adopt the turning process. However, in the way of compound machining of cold rolling expansion and turning, at least two clampings are required, and it is more difficult to guarantee the positional accuracy between the sealing inclined surface and the raceway, and still cannot well meet the design requirements. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a cold rolling device and a cold rolling expansion processing technology for sealing the inner ring of a bearing. By reasonably designing the cold rolling groove, the one-time processing and forming of the sealing bearing inner ring can be realized, which not only effectively ensures the processing accuracy requirements, but also has the advantages of high production efficiency.

[0008] To solve the above technical problems, the technical solution provided by the present invention is as follows: A cold rolling device for sealing the inner ring of a bearing, including a rolling wheel and a core roll. The rolling wheel is provided with a cold rolling groove.

[0009] The bottom surface of the cold rolling groove is provided with a plurality of feature forming parts, and the feature forming parts are defined to be arranged annularly around the center line of the rolling wheel; the feature forming parts include a groove forming protrusion part and two forming inclined surfaces, and the groove forming protrusion part is located between the two forming inclined surfaces; the forming inclined surfaces are arranged towards the groove forming protrusion part and are inclined outwards relative to the groove forming protrusion part.

[0010] The included angle between the forming inclined surface and any radial section of the rolling wheel is A; the axial distance between the upper edge of one forming inclined surface and the top of the groove forming protrusion part is M, and the axial distance between the upper edge of the other forming inclined surface and the top of the groove forming protrusion part is N.

[0011] Then: A = 30 ± 2°, |M - N| ≤ 0.03 mm.

[0012] The core roll is provided with a positioning groove, and the positioning groove is arranged annularly around the center line of the core roll; during processing, the center line of the core roll is arranged parallel to the center line of the rolling wheel, and the positioning groove is aligned with the cold rolling groove.

[0013] The positioning groove is used for the axial limit of the blank, and the cold rolling groove is used to apply pressure to the blank and extrude the blank to form a groove and a sealing inclined surface.

[0014] By reasonably setting the cold rolling groove, the cold rolling device of the present application can simultaneously form the groove and the sealing inclined surface in the form of cold rolling processing, effectively ensuring the dimensional accuracy of the sealing inclined surface and the groove, and at the same time reliably controlling the positional tolerance between the sealing inclined surface and the groove, improving the product quality. At the same time, compared with the cold rolling process in the background technology, the cold rolling device of the present application simplifies the processing steps and has higher production efficiency.

[0015] Preferably, a transition plane is formed between the groove forming protrusion part and the forming inclined surface, and a transition fillet is provided between the transition plane and the forming inclined surface.

[0016] Preferably, a transition inclined surface is provided between the groove forming protrusion part and the transition plane. The height of the groove forming protrusion part is H, and the height of the transition inclined surface is h. Then: h = 0.3 - 0.4H.

[0017] The settings of the transition fillets and transition chamfers can not only reduce the abrupt change in shape in the cold rolling groove, reduce stress concentration, but also ensure the full forming of the product, avoid local defects in the product, and improve the product quality.

[0018] Preferably, the two side faces of the cold rolling groove are inclined outward, and the included angle between the side face of the cold rolling groove and any radial section of the rolling wheel is B, and B = 4 ± 1°.

[0019] The outward inclination of the side face of the cold rolling groove facilitates the separation of the product from the cold rolling groove after forming, thereby improving the processing efficiency.

[0020] Preferably, a transition fillet is provided between the side face and the bottom face of the cold rolling groove.

[0021] Preferably, the surface hardness of the feature forming part is 58 - 62 HRC, and the surface roughness is 1.6 μm.

[0022] Preferably, pre-positioning surfaces are respectively provided between the bottom face and the two side faces of the positioning groove. The radial dimension of the pre-positioning surface is f, the axial dimension of the pre-positioning surface is g, the radial dimension of the positioning groove is F, and the axial dimension of the positioning groove is G; then: f = 0.6 - 0.7F, g = 0.15 - 0.2G.

[0023] During the conventional cold ring rolling process, due to the extrusion of the rolling wheel and the core roll, while the blank is being formed and its diameter is expanded, there is also a tendency for axial deformation. Even though the cold rolling groove can play a certain role in restraining the blank axially, the blank will inevitably have a certain amount of uncontrollable axial deformation, reducing the forming quality of the product.

[0024] However, when using the cold rolling equipment of the present application, after the blank is placed in the positioning groove, the pre-positioning surface plays a supporting role for the blank. The inner edge of the blank cannot contact the bottom face of the positioning groove, but a certain space, that is, a deformation interval, is formed between the inner edge and the bottom face of the positioning groove. When starting the cold rolling process, under the extrusion of the rolling wheel, especially under the extrusion force of the two forming inclined faces towards the inside, the blank gradually deforms towards the deformation interval during the forming process. The deformation interval plays a certain guiding role in the deformation of the blank, thereby reducing the tendency of the blank to deform axially to a certain extent, making the forming of the blank more controllable and improving the forming quality of the product.

[0025] A cold ring rolling process for sealing the inner ring of a bearing uses the cold rolling equipment as described above; it at least includes the following steps:

[0026] S01 Blank forming: Use a ring-shaped blank and pre-process a channel positioning groove on the side surface of the blank; the radial dimension of the channel positioning groove is b, the axial dimension of the blank is e, the height of the channel forming protrusion is H, and the width of the cold rolling groove is E. Then: b = 0.85 - 0.95H, E - e = 0.4 - 0.5 mm;

[0027] S02 Clamping: Set the blank on the core roller, with the inner part of the blank placed in the positioning groove;

[0028] S03 Cold rolling: The rolling wheel rotates, and the core roller drives the blank to move synchronously towards the rolling wheel. The blank enters the cold rolling groove and is formed under the combined pressure of the rolling wheel and the core roller.

[0029] Preferably, the following steps are further included:

[0030] S04 Post-treatment: Trim the end face of the product by grinding.

[0031] Preferably, in S03, the highest temperature of the part is 100 ± 10 °C, the forming time is 10 - 15 s / piece, and the forming pressure is 1.5 - 3.0 MPa. Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of a sealed bearing;

[0033] Figure 2 It is a schematic structural diagram of the inner ring of a sealed bearing;

[0034] Figure 3 It is for Figure 2 The partial enlarged view at C in;

[0035] Figure 4 It is a schematic structural diagram of the blank processed by the cold rolling equipment for the inner ring of the sealed bearing in this embodiment;

[0036] Figure 5 It is a schematic structural diagram of the cold rolling equipment for the inner ring of the sealed bearing in this embodiment;

[0037] Figure 6 It is a schematic structural diagram of the rolling wheel in the cold rolling equipment for the inner ring of the sealed bearing in this embodiment;

[0038] Figure 7 It is for Figure 6 The partial enlarged view at K in;

[0039] Figure 8 It is a schematic structural diagram of the core roller in the cold rolling equipment for the inner ring of the sealed bearing in this embodiment;

[0040] Figure 9 It is for Figure 8 The partial enlarged view at Q in;

[0041] Figure 10 This is a schematic structural view of the cooperation between the core roller and the blank in the cold rolling equipment for sealing the inner ring of the bearing in this embodiment;

[0042] Figure 11 is Figure 10 a partial enlarged view at Y in;

[0043] Figure 12 This is a schematic structural view of the processing state of the cold rolling equipment for sealing the inner ring of the bearing in this embodiment. Specific embodiments

[0044] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Embodiment

[0045] As Figure 5 shown, a cold rolling equipment for sealing the inner ring of a bearing includes a rolling wheel 1 and a core roller 2, and a cold rolling groove 11 is provided on the rolling wheel 1. As Figure 6 and Figure 7 shown, specifically, the two side faces of the cold rolling groove 11 are inclined outward, and the angle between the side face of the cold rolling groove 11 and any radial section of the rolling wheel 1 is B, and B = 4 ± 1°. The side face of the cold rolling groove 11 is inclined outward, which is convenient for the product to be separated from the cold rolling groove 11 after forming, thereby improving the processing efficiency. A transition fillet is provided between the side face and the bottom face of the cold rolling groove 11.

[0046] As Figure 6 and Figure 7 shown, a plurality of feature forming parts are provided on the bottom face of the cold rolling groove 11, and the feature forming parts are defined to be annularly arranged around the center line of the rolling wheel 1. The feature forming parts include a channel forming protrusion 111 and two forming inclined surfaces 114, and the channel forming protrusion 111 is located between the two forming inclined surfaces 114. The forming inclined surface 114 faces the channel forming protrusion 111 and is inclined outward relative to the channel forming protrusion 111. The surface hardness of the feature forming parts is 58 - 62 HRC, and the surface roughness is 1.6 μm.

[0047] As Figure 6 and Figure 7As shown in the figure, specifically, a transition plane 113 is formed between the channel forming protrusion 111 and the forming inclined surface 114, and a transition fillet is provided between the transition plane 113 and the forming inclined surface 114. A transition inclined surface 112 is provided between the channel forming protrusion 111 and the transition plane 113. The height of the channel forming protrusion 111 is H, and the height of the transition inclined surface 112 is h. Then: h = 0.3 - 0.4H. The setting of the transition fillet and the transition inclined surface 112 can not only reduce the shape mutation in the cold rolling groove 11 and reduce the stress concentration, but also ensure the full forming of the product, avoid local defects in the product, and improve the product quality.

[0048] As Figure 6 and Figure 7 shown in the figure, the included angle between the forming inclined surface 114 and any radial section of the rolling wheel 1 is A, and A = 30 ± 2°. The axial distance between the upper edge of one forming inclined surface 114 and the top of the channel forming protrusion 111 is M, and the axial distance between the upper edge of the other forming inclined surface 114 and the top of the channel forming protrusion 111 is N. |M - N| ≤ 0.03 mm.

[0049] As Figure 8 and Figure 9 shown in the figure, a positioning groove 21 is provided on the core roll 2, and the positioning groove 21 is arranged annularly around the center line of the core roll 2. During processing, the center line of the core roll 2 is arranged parallel to the center line of the rolling wheel 1, and the positioning groove 21 is aligned with the cold rolling groove 11.

[0050] The positioning groove 21 is used for the axial limit of the blank 04, and the cold rolling groove 11 is used to apply pressure to the blank 04 and extrude the blank 04 to form a channel and a sealing inclined surface.

[0051] Specifically, as Figure 8 and Figure 9 shown in the figure, pre-positioning surfaces 22 are respectively provided between the bottom surface and the two side surfaces of the positioning groove 21. The radial dimension of the pre-positioning surface 22 is f, the axial dimension of the pre-positioning surface 22 is g, the radial dimension of the positioning groove 21 is F, and the axial dimension of the positioning groove 21 is G. Then: f = 0.6 - 0.7F, g = 0.15 - 0.2G.

[0052] During the conventional cold rolling and expanding process, due to the extrusion of the rolling wheel 1 and the core roll 2, while the blank 04 is being formed and expanded in diameter, there is also a tendency for axial deformation. Even though the cold rolling groove 11 can play a certain role in restricting the blank 04 axially, the blank 04 will inevitably have a certain amount of uncontrollable axial deformation, reducing the forming quality of the product.

[0053] When using the cold rolling equipment of the present application, after the blank 04 is placed in the positioning groove 21, the pre-positioning surface 22 supports the blank 04. The inner edge of the blank 04 cannot contact the bottom surface of the positioning groove 21, but a certain space, that is, the deformation interval 23, is formed between the inner edge and the bottom surface of the positioning groove 21. When starting the cold rolling process, under the extrusion of the rolling wheel 1, especially under the inward extrusion force of the two forming inclined surfaces 114, the blank 04 gradually deforms towards the deformation interval 23 during the forming process. The deformation interval 23 plays a certain guiding role in the deformation of the blank 04, thereby reducing the tendency of the blank 04 to deform along the axial direction to a certain extent, making the forming of the blank 04 more controllable and improving the forming quality of the product.

[0054] Specifically, as Figure 8 and Figure 9 shown, the pre-positioning surface 22 includes a first segment 221 connected to the side surface of the positioning groove 21 and a second segment 222 corresponding to the bottom surface of the positioning groove 21. The first segment 221 and the second segment 222 are inclined surfaces, and the angle α between the first segment 221 and the radial cross-section of the core roller 2 is 20° - 30°, and the angle β between the second segment 222 and the radial cross-section of the core roller 2 is 70° - 80°. The transition between the side surface and the bottom surface usually adopts a rounded corner or chamfer form. However, the shape mutation of the rounded corner form is too large in the edge area, and it cannot achieve a good support and positioning effect. Once the chamfer form has a large size setting, the weakening effect on the mechanical properties of the product is too large. Therefore, the pre-positioning surface 22 is set in a segmented form. The first segment 221 mainly undertakes the support and positioning of the blank 04, and the second segment 222 is mainly used to control the inner edge forming of the product, that is, to form a chamfer at the inner edge of the product. The segmented setting of the pre-positioning surface 22 can take into account both the support and positioning effect and the mechanical properties of the product.

[0055] Furthermore, the first segment 221 and the second segment 222 are transitioned by an arc to reduce stress concentration.

[0056] By reasonably setting the cold rolling groove 11, the cold rolling equipment of the present application can simultaneously form the groove and the sealing inclined surface in the form of cold rolling, effectively ensuring the dimensional accuracy of the sealing inclined surface and the groove, and at the same time reliably controlling the position tolerance between the sealing inclined surface and the groove, improving the product quality. At the same time, compared with the cold rolling process in the background technology, when using the cold rolling equipment of the present application, the processing steps are simplified and the production efficiency is higher.

[0057] A cold rolling expansion processing technology for sealing the inner ring of a bearing uses the cold rolling equipment as described above; it at least includes the following steps:

[0058] S01 Blank 04 Forming: Use an annular blank 04, and pre-process a channel positioning groove 21041 on the side surface of the blank 04. The radial dimension of the channel positioning groove 21041 is b, and the axial dimension of the blank 04 is e; the height of the channel forming protrusion 111 is H, the width of the cold rolling groove 11 is E, and the width of the positioning groove 21 is F; then: b = 0.85 - 0.95H, E - e = 0.4 - 0.5 mm, F - e = 0.4 - 0.5 mm. Refer to the blank structure Figure 4 as shown.

[0059] S02 Clamping: As shown in Figure 10 and Figure 11 shown, sleave the blank 04 on the core roller 2, and a part of the inner edge of the blank 04 is placed in the positioning groove 21 and contacts the pre-positioning surface 22.

[0060] S03 Cold Rolling: The rolling wheel 1 rotates, the core roller 2 drives the blank 04 to move synchronously towards the rolling wheel 1, the blank 04 enters the cold rolling groove 11, and is formed under the combined pressure of the rolling wheel 1 and the core roller 2. During the cold rolling process, the maximum temperature of the part is 100 ± 10 °C, the forming time is 10 - 15 s / piece, and the forming pressure is 1.5 - 3.0 MPa. Controlling the forming temperature can avoid the formation of an oxide layer on the product surface, and controlling the forming time and forming pressure can effectively ensure the forming effect. That is, in the state as shown in Figure 12 shown.

[0061] S04 Post-treatment: Use grinding to trim the end face of the product.

[0062] Using the above cold rolling and expanding processing technology, the dimensional errors of the channel and the sealing inclined surface can be effectively controlled, and at the same time, the position error between the channel and the sealing inclined surface can be ensured. The surface roughness of the channel and the sealing inclined surface can reach 0.1 μm, which is much higher than the 3.2 μm achieved by the conventional processing technology. The product quality is reliable and the processing efficiency is high.

[0063] In summary, the above are only the preferred embodiments of the present invention, and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cold rolling device for sealing the inner ring of a bearing, comprising a rolling wheel and a core roll. The rolling wheel is provided with a cold rolling groove. It is characterized in that: Several feature forming parts are provided on the bottom surface of the cold rolling groove. The feature forming parts are defined to be arranged annularly around the center line of the rolling wheel; the feature forming parts include a channel forming convex part and two forming inclined surfaces. The channel forming convex part is located between the two forming inclined surfaces; the forming inclined surfaces are arranged towards the channel forming convex part and are inclined outwards relative to the channel forming convex part; The included angle between the forming inclined surface and any radial section of the rolling wheel is A; the axial distance between the upper edge of one forming inclined surface and the top of the channel forming convex part is M, and the axial distance between the upper edge of the other forming inclined surface and the top of the channel forming convex part is N; Then: A = 30 ± 2°, |M - N| ≤ 0.03 mm; A positioning groove is provided on the core roll. The positioning groove is arranged annularly around the center line of the core roll; during processing, the center line of the core roll is arranged parallel to the center line of the rolling wheel, and the positioning groove is aligned with the cold rolling groove; Pre-positioning surfaces are respectively provided between the bottom surface and the two side surfaces of the positioning groove. The radial dimension of the pre-positioning surface is f, the axial dimension of the pre-positioning surface is g, the radial dimension of the positioning groove is F, and the axial dimension of the positioning groove is G; then: f = 0.6 - 0.7F, g = 0.15 - 0.2G; The pre-positioning surface includes a first segment connected to the side surface of the positioning groove and a second segment corresponding to the bottom surface of the positioning groove. The first segment and the second segment are inclined surfaces, and the included angle α between the first segment and the radial section of the core roll is 20° - 30°, and the included angle β between the second segment and the radial section of the core roll is 70° - 80°.

2. The cold rolling equipment according to claim 1, wherein: A transition plane is formed between the channel forming convex part and the forming inclined surface, and a transition fillet is provided between the transition plane and the forming inclined surface.

3. The cold rolling equipment according to claim 2, wherein: A transition inclined surface is provided between the channel forming convex part and the transition plane. The height of the channel forming convex part is H, and the height of the transition inclined surface is h. Then: h = 0.3 - 0.4H.

4. The cold rolling equipment according to claim 1, characterized in that: The two side surfaces of the cold rolling groove are inclined outwards, and the included angle between the side surface of the cold rolling groove and any radial section of the rolling wheel is B. Then: B = 4 ± 1°.

5. The cold rolling equipment according to claim 1, characterized in that: A transition fillet is provided between the side surface and the bottom surface of the cold rolling groove.

6. The cold rolling equipment according to claim 1, characterized in that: The surface hardness of the feature forming part is 58 - 62 HRC, and the surface roughness is 1.6 μm.

7. A cold ring rolling process for sealing the inner ring of a bearing, characterized in that: Using the cold rolling device according to any one of claims 1 - 6; at least including the following steps: S01 Blank forming: Using an annular blank, and pre-processing a channel positioning groove on the side surface of the blank; the radial dimension of the channel positioning groove is b, the axial dimension of the blank is e, the height of the channel forming convex part is H, and the width of the cold rolling groove is E. Then: b = 0.85 - 0.95H, E - e = 0.4 - 0.5 mm; S02 Clamping: Sleeving the blank on the core roll, and placing the inner part of the blank in the positioning groove; S03 Cold rolling: The rolling wheel rotates, the core roll drives the blank to move towards the rolling wheel synchronously, the blank enters the cold rolling groove, and is formed under the combined pressure of the rolling wheel and the core roll.

8. The cold ring rolling process according to claim 7, wherein: It also includes the following steps: S04 Post-treatment: The end face of the product is trimmed by grinding.

9. The cold ring rolling process according to claim 7 or 8, characterized in that: In S03, the maximum temperature of the part is 100 ± 10 °C, the forming time is 10 - 15 s per piece, and the forming pressure is 1.5 - 3.0 MPa.

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