A grinding method and grinding machine for guide roller for superfinishing tapered roller

Abstract

A method and a grinding machine for grinding guide rollers for super-finishing tapered rollers, which relate to the technical field of bearing processing. The method is as follows: the guide rollers are ground using a flat grinding wheel of a grinding machine, and during grinding, the axis of the grinding wheel has an inclination angle relative to the axis of the guide roller in a vertical plane parallel to the axis of the guide roller, and the axis of the grinding wheel also has an inclination angle relative to the axis of the guide roller in a horizontal plane, and the outer peripheral surface of the flat grinding wheel of the grinding machine is trimmed into two conical surfaces of a larger and a smaller width, and the spiral surface of the guide roller is ground using the conical surface with a larger width, and the spiral rib of the guide roller is ground using the conical surface with a smaller width, and a corresponding grinding machine is designed according to the grinding method. Beneficial effects of the invention: The invention can greatly improve the grinding quality and efficiency of the spiral rib of the guide roller while meeting the requirements for the grinding of the inclination angle of the guide roller rib and the spiral surface of the guide roller, and is suitable for both ordinary tapered rollers and the grinding of precision tapered roller super-finishing guide rollers.

Description

Technical Field

[0001] The invention belongs to the technical field of bearing processing, and in particular relates to a grinding method and a grinding machine for a guide roller for super-finishing a tapered roller. Background Art

[0002] Tapered roller is an important part of rolling bearing, and its conical surface needs to be ground and super-finished. The grinding and super-finishing of the conical surface of the tapered roller usually adopts the centerless through-type processing method. The guide roller used in super-finishing and the guide wheel used in grinding are both important special parts that play the role of the main shaft. Their own processing accuracy directly affects the processing quality of the tapered roller. The main working surfaces of the guide roller are two spiral working surfaces that are in direct contact with the roller. One is the spiral surface that contacts the rolling surface of the roller, and the other is the spiral rib that contacts the base surface of the roller ball. Due to the special structure of the spiral working surface of the guide roller, the structural parameters need to be specially designed according to the roller model and super-finishing processing requirements, and the grinding accuracy requirements are high, so a special guide roller grinder is required for grinding. The two main working surfaces of the guide roller are easy to wear, and after wear, they need to be repaired and ground before they can be reused. The working surface on the guide wheel that directly contacts the tapered roller has a similar structure and usage characteristics to the guide roller. Therefore, the grinding method and grinder of the guide roller can also be used for guide wheel grinding. As a special grinder for grinding guide rollers and guide wheels, it is required to be able to grind both spiral surfaces and spiral ribs. The super-finishing process using guide rollers is always arranged after the grinding process using guide wheels. In addition, the length of guide rollers is usually much longer than that of guide wheels. Therefore, the grinding requirements and grinding difficulty of guide rollers are often higher than those of guide wheels. Traditionally, guide wheel grinders can only grind guide wheels but not guide rollers. With the promotion of super-finishing technology, the demand for grinding guide rollers has increased. After improvement, guide wheel grinders have the function of grinding guide rollers, but the current name is still customarily called guide wheel grinders. The guide roller grinding method and grinder described in the present invention are suitable for guide wheel grinding and guide wheel grinders.

[0003] The characteristics of the existing guide roller grinder and guide roller grinding method include: (1) The axis of the guide roller is parallel to the straight line of movement of the worktable; the axis of the grinding wheel remains parallel to the axis of the guide roller in the horizontal plane and is inclined in the vertical plane. The inclination angle is the vertical swing angle of the grinding wheel frame and is adjustable. (2) A flat grinding wheel is used, and the outer peripheral surface of the grinding wheel is trimmed into a single conical surface, and the end surface of the grinding wheel is not trimmed. (3) When grinding the spiral rib of the guide roller, the inclination angle of the grinding wheel axis in the vertical plane is adjusted according to the helix angle of the guide roller rib and the inclination angle of the rib relative to the axis of the guide roller, and the spiral rib of the guide roller is ground with the help of the arc line at the large end of the outer peripheral conical surface of the grinding wheel.

[0004] The existing guide roller grinding method does not perform dressing on the end face of the grinding wheel in order to avoid affecting the grinding of the spiral surface of the guide roller. When grinding the spiral surface of the guide roller, the width of the grinding wheel must be slightly larger than the width of the spiral surface of the guide roller. If the end face of the grinding wheel is dressed, the width of the grinding wheel will decrease as the amount of dressing increases, thereby affecting the grinding of the spiral surface of the guide roller.

[0005] Regarding the problem of grinding the spiral rib of the guide roller by means of the arc line at the large end of the outer peripheral conical surface of the grinding wheel, a paper entitled "Analysis of the rib profile of the guide roller for superfinishing of tapered rollers" published in the journal "Bearings" No. 8, 2013 (hereinafter referred to as Public Document 1) has been analyzed in detail. According to Public Document 1, when grinding the spiral rib of the guide roller by means of the arc line at the large end of the outer peripheral conical surface of the grinding wheel, in order to meet the requirement of the inclination angle of the rib relative to the axis of the guide roller, the vertical swing angle of the grinding wheel frame needs to be smaller than the helix angle of the guide roller rib, so as to grind the rib by means of the arc line at the large end of the outer peripheral conical surface of the grinding wheel.

[0006] The existing method of grinding the spiral rib of the guide roller is that only the arc line at the large end of the outer peripheral conical surface of the grinding wheel is involved in the grinding, so the surface quality after grinding is very poor, which is difficult to meet the requirements of precision tapered roller superfinishing processing and also affects the service life of the guide roller. During the tapered roller superfinishing process, there is a large thrust between the spiral rib of the guide roller and the base surface of the roller ball, and they are in a sliding state. If the surface roughness of the guide roller rib is large, it is easy to produce scratches or even scratches on the base surface of the roller ball. In addition, the greater the surface roughness of the guide roller rib, the easier it is to wear, thereby affecting the service life of the guide roller. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a grinding method and a grinding machine for a guide roller for superfinishing a tapered roller, so as to overcome the shortcomings of the prior art, improve the grinding quality of the spiral rib of the guide roller, and at the same time meet the grinding requirements of the spiral surface of the guide roller.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a method for grinding a guide roller for super-finishing a tapered roller, the grinding method uses a flat grinding wheel of a grinding machine to grind the guide roller, during grinding, the axis of the grinding wheel has an inclination angle ε relative to the axis of the guide roller in a vertical plane parallel to the axis of the guide roller, and the axis of the grinding wheel also has an inclination angle θ relative to the axis of the guide roller in a horizontal plane, the outer peripheral surface of the flat grinding wheel of the grinding machine is trimmed into two conical surfaces of different widths, the larger conical surface is used to grind the spiral surface of the guide roller, and the smaller conical surface is used to grind the spiral rib of the guide roller.

[0009] In the method for grinding a guide roller for superfinishing a tapered roller of the present invention, the inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane ranges from 10° to 20°.

[0010] In the method for grinding a guide roller for superfinishing a tapered roller of the present invention, the value of the inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane is 15°.

[0011] A grinding machine for guide rollers for superfinishing tapered rollers, the grinding machine adopts a flat grinding wheel, the grinding wheel axis has an inclination angle ε relative to the guide roller axis in a vertical plane parallel to the guide roller axis, and has an inclination angle θ relative to the guide roller axis in a horizontal plane, the outer peripheral surface of the flat grinding wheel is trimmed into two conical surfaces of larger and smaller widths, the conical surface with a larger width is called the large conical surface, which is used for grinding the spiral surface of the guide roller; the conical surface with a smaller width is called the small conical surface, which is used for grinding the spiral rib of the guide roller.

[0012] In the grinding machine for guide rollers for superfinishing tapered rollers of the present invention, the inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane ranges from 10° to 20°.

[0013] In the grinding machine for guide rollers for superfinishing tapered rollers of the present invention, the value of the inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane is 15°.

[0014] The beneficial effects of the present invention are: while meeting the requirements for the grinding of the inclination angle of the rib and the spiral surface of the guide roller, the grinding quality of the spiral rib of the guide roller is greatly improved; the efficiency of the spiral rib of the guide roller and the durability of the grinding wheel are improved; it is suitable for grinding both ordinary tapered rollers and precision tapered roller super-finished guide rollers, and is also suitable for grinding guide wheels for centerless grinding of tapered rollers, and is specifically manifested as follows:

[0015] (1) When grinding the spiral rib of the guide roller, in the existing method, only the large end arc line of the grinding wheel conical surface is involved in the grinding. Moreover, since the end surface of the grinding wheel is not trimmed, the abrasive grains on the large end arc line cannot all be involved in the grinding, resulting in very few abrasive grains actually involved in the grinding. Therefore, the grinding quality is poor, the efficiency is low, and the grinding wheel is easily blunted. In contrast, the grinding method and grinding machine of the present invention use the trimmed small conical surface of the grinding wheel to participate in the grinding. According to the grinding wheel grit size of 60 and the guide roller rib width of 1.5-3mm, the number of abrasive grains involved in the grinding is at least 5-10 times that of the existing method. Therefore, the grinding quality and grinding efficiency are greatly improved, and the durability of the grinding wheel is also greatly improved.

[0016] (2) According to the conjugate surface principle, based on the geometric relationship and relative motion relationship between the grinding wheel and the guide roller during guide roller grinding, the inclination angle of the spiral edge of the guide roller after grinding of the present invention can meet its design requirements. At the same time, the spiral surface of the guide roller after grinding of the present invention can also meet its design requirements.

[0017] (3) The surface quality of the spiral rib of the guide roller ground by the present invention is better than that of the existing method, and can also meet other requirements for guide roller grinding, so it is suitable for grinding precision tapered roller super-finishing guide rollers. At the same time, compared with the existing grinding method, the method and grinder of the present invention for grinding guide rollers does not impose additional requirements, does not increase costs, and improves efficiency, so it is also suitable for grinding ordinary tapered roller super-finishing guide rollers.

[0018] (4) The grinding method and grinding machine of the present invention are also applicable to the grinding of guide wheels for centerless grinding of tapered rollers, because the structures and usage characteristics of the spiral working surfaces of the guide wheels and guide rollers are similar. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the layout of the guide roller grinder of the present invention and the shape of the outer peripheral surface of the grinding wheel;

[0020] Figure 2 It is a schematic diagram of the structure of the spiral working surface of the guide roller represented in the axial plane of the guide roller of the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of the spiral working surface of the guide roller represented in the radial normal plane of the spiral of the guide roller rib of the present invention;

[0022] Figure 4 Schematic diagram of the relationship between the axial width of the large and small conical surfaces of the grinding wheel and the inclination angle θ of the grinding wheel axis;

[0023] Figure 5 It is a schematic diagram of the geometric relationship between the changes in the widths of the large and small conical surfaces caused by the dressing of the large and small conical surfaces of the grinding wheel of the present invention;

[0024] Figure 6 It is a schematic diagram of the geometric relationship between the grinding wheel and the guide roller in the vertical plane parallel to the axis of the guide roller of the present invention;

[0025] Figure 7 It is a schematic diagram of the geometric relationship between the grinding wheel and the guide roller represented in the radial normal plane of the guide roller rib spiral of the present invention;

[0026] Figure 8 The figure is a schematic diagram of the spatial geometric relationship between the contact line between the small conical surface of the grinding wheel and the guide roller rib and the grinding wheel axis and the guide roller axis of the present invention.

[0027] Markings in the figure: 1, grinding wheel, 2, guide roller. DETAILED DESCRIPTION

[0028] The specific implementation manner (embodiment) of the present invention is described below in conjunction with the accompanying drawings so that those skilled in the art can better understand the present invention.

[0029] A method for grinding a guide roller for superfinishing a tapered roller, wherein the guide roller is ground by using a flat grinding wheel of a grinding machine. During grinding, the axis of the grinding wheel has an inclination angle ε relative to the axis of the guide roller in a vertical plane parallel to the axis of the guide roller, and the axis of the grinding wheel also has an inclination angle θ relative to the axis of the guide roller in a horizontal plane. The outer peripheral surface of the flat grinding wheel of the grinding machine is trimmed into two conical surfaces of a larger width and a smaller width. The conical surface with a larger width is used to grind the spiral surface of the guide roller, and the conical surface with a smaller width is used to grind the spiral rib of the guide roller.

[0030] A grinding machine for guide rollers for superfinishing tapered rollers, the grinding machine adopts a flat grinding wheel, the grinding wheel axis has an inclination angle ε relative to the guide roller axis in a vertical plane parallel to the guide roller axis, and has an inclination angle θ relative to the guide roller axis in a horizontal plane, the outer peripheral surface of the flat grinding wheel is trimmed into two conical surfaces of larger and smaller widths, the conical surface with a larger width is called the large conical surface, which is used for grinding the spiral surface of the guide roller; the conical surface with a smaller width is called the small conical surface, which is used for grinding the spiral rib of the guide roller.

[0031] The inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane ranges from 10° to 20°.

[0032] The preferred value of the inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane is 15°.

[0033] The spiral surface of the guide roller and the spiral rib are ground respectively with the large cone surface and the small cone surface of the grinding wheel.

[0034] When using the large conical surface of the grinding wheel to grind the spiral surface of the guide roller, the large conical surface of the grinding wheel needs to be trimmed to ensure its grinding performance. At the same time, the width of the large conical surface of the grinding wheel should also be kept at an appropriate value slightly larger than the width of the spiral surface of the guide roller. When the width of the large conical surface of the grinding wheel is less than the appropriate value, the large conical surface can be trimmed to increase it; when the width of the large conical surface of the grinding wheel is greater than the required value, the small conical surface can be trimmed to reduce it.

[0035] When using the small conical surface of the grinding wheel to grind the spiral rib of the guide roller, the small conical surface of the grinding wheel also needs to be trimmed to ensure its grinding performance. At the same time, the width of the small conical surface of the grinding wheel should be larger than the width of the spiral rib of the guide roller. When the width of the small conical surface of the grinding wheel is less than the required value, the small conical surface can be trimmed to increase it.

[0036] The technical principle of the present invention to achieve the beneficial effects is further described below in conjunction with the accompanying drawings.

[0037] (1) Layout of the guide roller grinder of the present invention and shape of the outer peripheral surface of the grinding wheel

[0038] Figure 1 Schematic diagram of the layout of the guide roller grinder and the outer peripheral surface shape of the grinding wheel of the present invention, wherein OO is the grinding wheel axis, and O1O1 is the guide roller axis. Figure 1As shown, the grinding wheel axis has an inclination angle θ relative to the guide roller axis in the horizontal plane, and also has an inclination angle ε in the vertical plane parallel to the guide roller axis; the outer peripheral surface of the flat grinding wheel is trimmed into two conical surfaces of larger and smaller widths, of which the conical surface with a larger width is called the large conical surface, which is used to grind the spiral surface of the guide roller; the conical surface with a smaller width is called the small conical surface, which is used to grind the spiral rib of the guide roller.

[0039] (2) Structure of the spiral working surface of the guide roller

[0040] Figure 2 It is a schematic diagram of the structure of the spiral working surface of the guide roller represented in the axial plane of the guide roller. Figure 2 In the figure, the axial section of the spiral surface of the guide roller is a slightly concave inclined curve, and its inclination angle relative to the axis of the guide roller is called the roller bevel angle, which is represented by βg; the amount of concavity is usually only a few microns, and its concave feature is not drawn in the figure; the helix angle of the guide roller spiral rib is η, which is the angle between the straight line J2J2 and the axis of the guide roller; the straight line J1J1 represents the tangent plane of the spiral surface of the guide roller rib; J2J2 represents the plane passing through the normal line and radial straight line at any point on the guide roller spiral rib, hereinafter referred to as the radial normal plane of the guide roller rib spiral; the straight line J2J2 is perpendicular to J1J1.

[0041] Figure 3 It is a schematic diagram of the structure of the guide roller spiral working surface represented in the radial normal plane of the guide roller rib spiral. Figure 3 In the figure, the spiral rib section of the guide roller is an inclined straight line, and its inclination angle relative to the radial direction of the guide roller is called the rib inclination angle, denoted by ωg. The rib inclination angle ωg here is not the same as the rib inclination angle ω described in Public Document 1. Although both angles represent the degree of inclination of the guide roller rib relative to the axis of the guide roller, their reference planes and angle reference lines are different. The rib inclination angle ω described in Public Document 1 is measured in a plane passing through the axis of the guide roller with the axis of the guide roller as the reference line.

[0042] (3) Working method of the present invention when grinding the guide roller

[0043] The working mode when grinding the guide roller is that the grinding wheel rotates at high speed; the guide roller rotates on the workbench at a low speed and moves linearly with the workbench; when grinding the spiral surface of the guide roller, the grinding wheel moves horizontally and linearly to achieve tool setting and radial feeding of the guide roller; when grinding the spiral rib of the guide roller, the tool setting is achieved by combining the horizontal linear movement of the grinding wheel with the longitudinal linear movement of the workbench, and the axial feeding of the guide roller is achieved by the longitudinal linear movement of the workbench. The matching relationship between the rotation of the guide roller and the movement of the workbench is: for every rotation of the guide roller, the workbench moves the length of the guide roller lead. The axis of the guide roller is consistent with the linear direction of the workbench movement.

[0044] (4) Optimal inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane

[0045] Figure 4 It is a schematic diagram of the relationship between the axial width of the large and small cone surfaces of the grinding wheel and the inclination angle θ of the grinding wheel axis. Figure 4 In the figure, H1 is the width of the large cone surface of the grinding wheel along its axial direction, H2 is the width of the small cone surface of the grinding wheel along its axial direction, H is the total axial width of the grinding wheel, AB is the width of the large cone surface of the grinding wheel along its generatrix direction, BC is the width of the small cone surface of the grinding wheel along its generatrix direction, OO is the grinding wheel axis, O2O2 is the straight line of movement of the worktable, It is the angle between the large cone surface of the grinding wheel and the adjacent end surface of the grinding wheel. It is the angle between the small cone surface of the grinding wheel and the adjacent grinding wheel end surface; βs is the angle between the generatrix of the large cone surface of the grinding wheel in the horizontal plane and the straight line of movement of the worktable, that is, the axis of the guide roller, which is approximately equal to the roller bevel angle of the spiral surface of the guide roller. For tapered rollers with a semi-cone angle between 0.5° and 5°, the angle is approximately between 0.65° and 6.5°; ωs is the angle between the generatrix of the small cone surface of the grinding wheel in the horizontal plane and the radial direction of the guide roller, which is approximately equal to the inclination angle of the spiral rib of the guide roller, generally around 5°. According to Figure 4 The geometric relationship shown, the calculation formula of H1 and H2 is:

[0046]

[0047]

[0048] in,

[0049] From the perspective of grinding wheel abrasive consumption, H represents the total amount of grinding wheel abrasive, H1 represents the amount of abrasive consumed in the grinding of the guide roller spiral surface, H2 represents the amount of abrasive consumed in the grinding of the guide roller spiral rib, and the sum of H1 and H2 is equal to H. On the other hand, from the perspective of the amount of metal material that needs to be removed, the width of the guide roller spiral surface represents the amount of metal material that needs to be removed when the guide roller spiral surface is ground, and the width of the guide roller spiral rib represents the amount of metal material that needs to be removed when the guide roller spiral rib is ground. There is a certain proportional relationship between the grinding wheel abrasive consumption and the amount of metal material removed. Therefore, the ratio of H1 to H2 should be equal to the ratio of the width of the guide roller spiral surface to the width of the guide roller spiral rib.

[0050] The width of the spiral rib of the guide roller is relatively small, generally 1.5mm to 3mm; considering the convenience of tool setting and other factors, the width BC of the small conical surface of the grinding wheel along its generatrix direction is generally 3mm to 6mm, that is, the ratio k of BC to the width of the spiral rib of the guide roller is generally in the range of 2 to 4. The width of the spiral surface of the guide roller depends on the length of the tapered roller, and its value is often much larger than the width of the spiral rib of the guide roller, and is very close to the width AB of the large conical surface of the grinding wheel along its generatrix direction, that is, the ratio of AB to the width of the spiral surface of the guide roller is approximately equal to 1. Therefore, the ratio relationship between H1 and H2 is as follows:

[0051]

[0052] According to the ratio relationship between H1 and H2, and noting the calculation formulas of H1 and H2, the optimal value analysis formula of the inclination angle θ is as follows:

[0053] cos(θ+βs)=ksin(θ+ωs)

[0054] Among them, k is the ratio of the width of the small cone surface of the grinding wheel along its generatrix direction to the width of the spiral rib of the guide roller, and the value range is generally 2 to 4.

[0055] According to the above analytical formula for the preferred value of the inclination angle θ, and noting the value ranges of k, βs and ωs, it can be obtained that the preferred value range of the inclination angle θ is 10° to 20°. Therefore, the preferred value of the inclination angle θ of the grinding wheel axis relative to the guide roller axis in the horizontal plane is 15°.

[0056] (5) Guarantee of the width of the grinding wheel cone

[0057] When grinding the spiral surface of the guide roller with the large conical surface of the grinding wheel, the width of the large conical surface along its generatrix direction should be greater than the width of the spiral surface. However, due to the width of the spiral groove of the guide roller, the width of the large conical surface of the grinding wheel cannot be too large, so an appropriate value must be ensured. When grinding the spiral rib of the guide roller with the small conical surface of the grinding wheel, the width of the small conical surface of the grinding wheel along its generatrix direction should be greater than the width of the spiral rib of the guide roller.

[0058] The dressing of the large or small cone surface of the grinding wheel will cause the width of the large and small cone surfaces of the grinding wheel to change simultaneously. Figure 5 This is a schematic diagram of the change in the width of the large and small cones caused by the dressing of the large and small cones of the grinding wheel. In the figure, AB is the width of the large cone of the grinding wheel, BC is the width of the small cone of the grinding wheel, CD is the adjacent end face of the small cone of the grinding wheel, AE is the adjacent end face of the large cone of the grinding wheel, OO is the axis of the grinding wheel, A1B1 is the width of the large cone of the grinding wheel after dressing, and B1C1 is the width of the small cone of the grinding wheel after dressing. Since the angle between AB and AE and the angle between AB and BC are both obtuse angles, and the angle between BC and CD is also an obtuse angle, therefore, A1B1 is greater than AB, and B1C1 is greater than BC. This means that dressing the large cone will increase the width of the large cone and reduce the width of the small cone; dressing the small cone will increase the width of the small cone and reduce the width of the large cone.

[0059] According to the above-mentioned trend of the change in the width of the large and small conical surfaces of the grinding wheel caused by grinding wheel dressing, when the large conical surface of the grinding wheel is used to grind the spiral surface of the guide roller, if the width of the large conical surface of the grinding wheel is less than the required value, the large conical surface can be trimmed to increase it; if the width of the large conical surface of the grinding wheel is greater than the required value, the small conical surface can be trimmed to decrease it, thereby ensuring that the width of the large conical surface of the grinding wheel meets the grinding requirements. When the small conical surface of the grinding wheel is used to grind the spiral rib of the guide roller, if the width of the small conical surface of the grinding wheel is less than the required value, the small conical surface can be trimmed to increase it, thereby ensuring that the width of the small conical surface of the grinding wheel meets the grinding requirements.

[0060] (6) The design requirements for the inclination angle of the spiral rib of the guide roller after grinding are met

[0061] When the invention uses the grinding wheel small cone surface to grind the spiral rib of the guide roller, the design requirements of the rib inclination angle can be met by rationally selecting two parameters, namely, the vertical swing angle of the grinding wheel frame and the semi-cone angle of the grinding wheel small cone surface.

[0062] The vertical swing angle of the grinding wheel frame is ε2, and the half cone angle of the small cone surface of the grinding wheel is β2. The selection of β2 and ε2 must not only meet the design requirements of the inclination angle of the guide roller spiral rib, but also ensure that the small cone surface of the grinding wheel participates in the grinding, and it cannot be that only one arc on the grinding wheel participates in the grinding as in the existing method. To this end, the axis of the grinding wheel is located in the radial normal plane of the guide roller rib spiral, and the inclination angle of the truncated straight line of the small cone surface of the grinding wheel in the plane relative to the radial direction of the guide roller is equal to the inclination angle ωg of the guide roller rib. In this case, the linear velocity direction of the small cone surface of the grinding wheel at the point where it contacts the guide roller spiral rib is exactly the tangent direction of the spiral surface of the guide roller spiral rib, and the small cone surface of the grinding wheel can maintain line contact with the guide roller spiral rib, and the contact line is the axial contour line of the small cone surface of the grinding wheel. Therefore, on the one hand, it can ensure that the small cone surface of the grinding wheel participates in the grinding, and on the other hand, it can ensure that the inclination angle of the guide roller rib after grinding is equal to the inclination angle ωg of the truncated straight line of the small cone surface of the grinding wheel in the radial normal plane of the guide roller rib spiral relative to the radial direction of the guide roller.

[0063] The geometric relationship between the grinding wheel and the guide roller in the vertical plane parallel to the axis of the guide roller is as follows: Figure 6 The geometric relationship between the grinding wheel and the guide roller in the radial normal plane of the guide roller rib spiral is shown in Figure 7 The grinding wheel axis is located in the radial normal plane of the guide roller rib spiral. Figure 6 In the vertical plane parallel to the axis of the guide roller, the angle between the axis of the grinding wheel and the axis of the guide roller is equal to the helix angle η of the guide roller rib; Figure 7 In the spiral radial normal plane of the guide roller rib shown in the figure, the truncation straight line of the small cone surface of the grinding wheel is consistent with the truncation straight line of the guide roller rib, and the overlapping part of the two is the contact straight line between the small cone surface of the grinding wheel and the guide roller rib. Its inclination angle relative to the radial direction of the guide roller is equal to the inclination angle ωg of the guide roller rib, and its inclination angle relative to the axis of the grinding wheel is equal to the half cone angle β2 of the small cone surface of the grinding wheel.

[0064] The spatial geometric relationship between the small conical surface of the grinding wheel and the contact line between the guide roller rib and the grinding wheel axis and the guide roller axis is as follows: Figure 8 As shown in the figure, P2P2 is the contact straight line between the small cone surface of the grinding wheel and the guide roller rib, OO is the grinding wheel axis, and O1O1 is the guide roller axis.

[0065] according to Figure 8 The geometric relationship shown in the figure, if θ, η and the design required ωg values ​​are known, the values ​​of β2 and ε2 can be calculated. In this way, by selecting the vertical swing angle of the grinding wheel frame and the semi-cone angle of the small cone surface of the grinding wheel according to the calculated values ​​of β2 and ε2, it can be ensured that the inclination angle ωg of the retaining edge reaches the design required value, and at the same time, the small cone surface of the grinding wheel is involved in grinding.

[0066] (7) Improvement of grinding quality and efficiency of guide roller spiral ribs

[0067] When grinding the spiral rib of the guide roller, in the existing method, only the large end arc line of the grinding wheel conical surface is involved in the grinding, and because the end surface of the grinding wheel is not trimmed, the abrasive grains on the large end arc line cannot all participate in the grinding, so that very few abrasive grains actually participate in the grinding, and thus the grinding quality is poor, the efficiency is low, and the grinding wheel is easily blunted; in contrast, the grinding method and the grinding machine of the present invention use the trimmed small conical surface of the grinding wheel to participate in the grinding, and according to the grinding wheel grit size of 60 and the guide roller rib width of 1.5-3mm, the number of abrasive grains involved in the grinding is at least 5-10 times higher than that of the existing method, and when the grinding wheel grit size increases, the number of abrasive grains involved in the grinding increases more, so the grinding quality and grinding efficiency are greatly improved, and the durability of the grinding wheel is also greatly improved.

[0068] When the present invention uses the small conical surface of the grinding wheel to grind the guide roller rib, the axis of the grinding wheel is located in the spiral radial normal plane of the guide roller rib. Therefore, the small conical surface of the grinding wheel and the guide roller rib only form linear contact in this plane and do not contact at other positions, thereby ensuring that the small conical surface of the grinding wheel participates in the grinding.

[0069] In contrast, in the existing grinding method, only the arc line at the large end of the grinding wheel cone surface is involved in the grinding, see Public Document 1.

[0070] (8) Meeting the design requirements of the spiral surface of the guide roller after grinding

[0071] When the invention uses the grinding wheel large cone surface to grind the spiral surface of the guide roller, the design requirements can be met through the reasonable selection of two parameters: the vertical swing angle of the grinding wheel frame and the semi-cone angle of the grinding wheel large cone surface.

[0072] The paper entitled "Analysis of the Cone-Cylinder Matching Guide Roller Surface of Tapered Roller Superfinishing with Convexity" published in the journal "Chinese Journal of Mechanical Engineering" in November 2018, vol. 54, No. 21, hereinafter referred to as Public Document 2, gives the ideal surface equation of the tapered roller oblique through-type superfinishing guide roller in its sections 3.1 and 3.2, and explains the characteristics of the ideal surface, indicating that the axial section of the guide roller spiral surface is a slightly concave inclined curve, and its characteristics can be expressed by two parameters: roller concavity and roller taper angle (that is, the roller bevel angle βg mentioned earlier in this specification). When the roller bevel angle described in Public Document 2 is equal to zero, it is upright through-type superfinishing. Public Document 2 does not limit the value of the roller bevel angle, so its ideal guide roller surface equation is applicable to both oblique and upright methods. These two methods are the main methods of tapered roller through-type superfinishing.

[0073] The paper entitled "Grinding Roller Shape and Precision Measurement of Superfinished Tapered Roller Guide Roller" published in the journal "Bearings" No. 8, August 2015, hereinafter referred to as Public Document 3, in its Section 1, based on the conjugate surface principle, based on the geometric relationship and relative motion relationship between the grinding wheel and the guide roller during the grinding process, established the spiral surface equation of the superfinished tapered roller guide roller after grinding, and explained its surface characteristics and the influence of grinding parameters such as the grinding wheel semi-cone angle and the vertical swing angle of the grinding wheel frame on the spiral surface. It shows that the axial section of the spiral surface of the guide roller after grinding is also a slightly concave inclined curve, and its characteristics can also be expressed by two parameters: roller concavity and roller cone angle (i.e., the roller bevel angle mentioned in the previous text of this specification); with different values ​​of grinding parameters such as the grinding wheel semi-cone angle and the vertical swing angle of the grinding wheel frame, the roller cone angle and roller concavity of the spiral surface of the guide roller change accordingly.

[0074] According to public document 3, by properly selecting the grinding wheel semi-cone angle and the grinding wheel frame vertical swing angle, the spiral surface of the guide roller after grinding can be very close to the designed surface in terms of roller bevel angle and roller concavity, thereby meeting the design requirements.

[0075] From the perspective of grinding forming principle, the fundamental reason why the axial section of the grinding roller shape described in Publication 3 has the characteristics of inclination and concaveness is that the outer peripheral surface of the grinding wheel is a conical surface, and the grinding wheel axis and the guide roller axis are in a spatially staggered relationship. The outer peripheral surface of the grinding wheel of the present invention is also a conical surface, and the grinding wheel axis and the guide roller axis are also in a spatially staggered relationship. The axial section of the guide roller surface after grinding also has the characteristics of inclination and concaveness. Therefore, through the reasonable selection of the two parameters of the vertical swing angle of the grinding wheel frame and the semi-cone angle of the large cone surface of the grinding wheel, the design requirements of the guide roller surface can also be met.

[0076] The surface quality of the spiral rib of the guide roller ground by the present invention is better than that of the existing method, and can also meet other requirements of guide roller grinding, so it is suitable for grinding precision tapered roller super-finishing guide rollers. At the same time, compared with the existing grinding method, the method and grinder of the present invention for grinding guide rollers does not impose additional requirements, does not increase the cost, and improves the efficiency, so it is also suitable for grinding ordinary tapered roller super-finishing guide rollers.

[0077] The method and grinding machine of the present invention are also suitable for grinding guide wheels for centerless grinding of tapered rollers, because the structures and usage characteristics of the spiral working surfaces of the guide wheels and guide rollers are similar.

Claims

1. A method for grinding a guide roller for superfinishing a tapered roller, wherein the guide roller is ground using a flat grinding wheel of a grinding machine, and during grinding, the axis of the grinding wheel has an inclination angle relative to the axis of the guide roller in a vertical plane parallel to the axis of the guide roller. e , characterized in that: The grinding wheel axis also has an inclination angle relative to the guide roller axis in the horizontal plane. I, The outer peripheral surface of the flat grinding wheel of the grinder is trimmed into two conical surfaces of different widths. The larger conical surface is used to grind the spiral surface of the guide roller, and the smaller conical surface is used to grind the spiral rib of the guide roller. The width of the small conical surface of the grinding wheel along its generatrix is ​​greater than the width of the spiral rib of the guide roller, and the ratio of the two is 2-4. The ratio of the width of the large conical surface of the grinding wheel along its generatrix to the width of the spiral surface of the guide roller is 1.

2. The method for grinding a guide roller for superfinishing a tapered roller according to claim 1, characterized in that: The inclination angle of the grinding wheel axis relative to the guide roller axis in the horizontal plane i The value range is 10°~20°.

3. The method for grinding a guide roller for superfinishing a tapered roller according to claim 2, characterized in that: The inclination angle of the grinding wheel axis relative to the guide roller axis in the horizontal plane i The value is 15°.

4. A grinding machine for guide rollers for superfinishing tapered rollers, the grinding machine using a flat grinding wheel, the grinding wheel axis having an inclination angle relative to the guide roller axis in a vertical plane parallel to the guide roller axis e , characterized in that: The grinding wheel axis also has an inclination angle relative to the guide roller axis in the horizontal plane. i The outer peripheral surface of the flat grinding wheel is trimmed into two conical surfaces of different widths. The conical surface with a larger width is called the large conical surface, which is used to grind the spiral surface of the guide roller; the conical surface with a smaller width is called the small conical surface, which is used to grind the spiral rib of the guide roller. The width of the small conical surface of the grinding wheel along its generatrix is ​​greater than the width of the spiral rib of the guide roller, and the ratio of the two is 2-4. The ratio of the width of the large conical surface of the grinding wheel along its generatrix to the width of the spiral surface of the guide roller is 1.

5. A grinding machine for guide rollers for superfinishing tapered rollers according to claim 4, characterized in that: The inclination angle of the grinding wheel axis relative to the guide roller axis in the horizontal plane i The value range is 10°~20°.

6. The grinding machine for guide rollers for superfinishing tapered rollers according to claim 5 is characterized in that: The inclination angle of the grinding wheel axis relative to the guide roller axis in the horizontal plane i The value is 15°.

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