Tapered roller grinding method and device based on large end ball base surface as reference positioning

Abstract

The invention discloses a method and device for grinding a tapered roller based on a large-end ball base surface as a reference positioning. A reverse positioning mechanism is installed at the front end of a guide plate of a centerless grinder. The reverse positioning mechanism comprises a positioning crank arm, the middle part of which is rotatably connected to the guide plate through a hinge shaft, one end of the positioning crank arm is provided with an elastic preload rod, the guide plate is provided with a rear positioning block and a front positioning shaft, the rear positioning block and the front positioning shaft respectively define the positioning crank arm and the elastic preload rod; during grinding, the elastic preload rod, the front positioning shaft and the rear positioning block are adjusted so that the other end of the positioning crank arm contacts with the large-end ball base surface of the tapered roller, so as to realize positioning grinding based on the large-end ball base surface of the roller, so that the tapered roller is based on the tapered roller ball base surface during grinding wheel correction, guide wheel correction, grinding and measurement; and the reverse positioning mechanism is highly consistent with the running track of the bearing when in use, so as to improve the accuracy grade, rotation speed and service life of the tapered roller bearing.

Description

Technical Field

[0001] The invention relates to a method for grinding a tapered roller, in particular to a method and a device for grinding a tapered roller based on a large end ball base surface as a reference for positioning. Background Art

[0002] At present, in the scope of mechanical assembly industry, in order to improve production efficiency and reduce production costs, it is necessary to increase the speed of bearings and extend their service life. Tapered roller bearings can bear radial force, axial force and a certain overturning moment load; tapered roller bearings can also be designed as double-row and four-row tapered roller bearings according to the requirements of installation conditions to meet different working conditions. They are favored by many designers in order to maximize the service life of equipment without increasing equipment investment; but the design limit speed of tapered roller bearings of the same size is lower than that of other types of bearings (deep groove ball, cylindrical roller bearings, etc.), especially large and extra-large tapered roller bearings. The use effect is worse.

[0003] As the research deepened, we conducted a systematic analysis of the traditional grinding method of tapered rollers, and found that the key factor restricting the quality of tapered roller grinding is that the positioning of the small end face of the tapered roller is contrary to the design principle; that is, the design principle requires that the center line of the tapered roller intersects with the outer ring raceway generatrix and the inner ring raceway generatrix at one point, and the intersection of the three lines must be tangent to the roller ball base surface, in order to achieve the pure rolling condition of the tapered roller bearing during use. The traditional tapered roller processing method uses the small end face of the tapered roller as the positioning reference and adopts the cut-in grinding method. It cannot ensure that the three-line intersection section and the roller ball base surface will form a tangent, which will cause the tapered roller bearing to slide during use, which will affect the service life and speed of the bearing. The main consideration for grinding tapered rollers on a centerless grinder using the small end face of the tapered roller as the positioning reference is to facilitate loading and unloading, while the inspection and use of tapered rollers are based on the large end ball base surface. If the tapered roller is replaced with the spherical base surface as the reference surface during measurement, the batch grouping size of the finished roller will have a large deviation, which will increase the batch grouping labor, high rework rate and increase costs. The use of tapered rollers will cause the bearings to heat up easily when rotating at high speeds, greatly reduce the bearing limit speed, and seriously affect the service life of the bearings. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a tapered roller grinding method and device based on the large end ball base surface as reference positioning, which has a reasonable design, improves machining accuracy and prolongs service life.

[0005] The technical solution of the present invention is:

[0006] A method for grinding a tapered roller based on the large end ball base surface as a reference positioning comprises the following steps:

[0007] a. A reverse positioning mechanism is installed at the front end of the guide plate of the centerless grinder, and the reverse positioning mechanism includes a positioning crank arm, the middle part of which is rotatably connected to the guide plate through a hinge shaft, one end of the positioning crank arm is provided with an elastic preload rod, and the guide plate is provided with a rear positioning block and a front positioning shaft, and the rear positioning block and the front positioning shaft respectively define the positioning crank arm and the elastic preload rod;

[0008] b. During grinding, by adjusting the elastic preload rod, the front positioning shaft and the rear positioning block, the other end of the positioning arm is brought into contact with the large end ball base surface of the tapered roller, so as to achieve positioning grinding based on the large end ball base surface of the roller, so that the tapered roller is corrected with the grinding wheel, corrected with the guide wheel, ground and measured based on the tapered roller ball base surface, and the tapered roller is highly consistent with the running track of the bearing when in use.

[0009] The other end of the positioning crank arm is provided with an arc surface, and is in tangential contact with the large end ball base surface of the tapered roller. The outer end of the elastic preload rod is provided with a spherical handle for easy operation, and the elastic preload rod is made of elastic material.

[0010] The rear positioning block is fixed on the guide plate by connecting bolts, and its side surface is in contact with the side surface of the positioning crank arm. The front positioning shaft is tightly matched with the positioning hole on the guide plate.

[0011] A tapered roller grinding device based on the large end ball base surface as the reference positioning, including a positioning crank arm, the middle part of the positioning crank arm is rotatably connected to the guide plate through a hinge shaft, one end of the positioning crank arm is provided with an elastic preload rod, the guide plate is provided with a rear positioning block and a front positioning shaft, the rear positioning block and the front positioning shaft respectively define the positioning crank arm and the elastic preload rod, the other end of the positioning crank arm contacts the large end ball base surface of the tapered roller, and positioning grinding is achieved based on the large end ball base surface of the roller, so that the tapered roller is corrected with the tapered roller ball base surface as the reference during grinding wheel correction, guide wheel correction, grinding, and measurement; and it is highly consistent with the running track of the bearing when in use.

[0012] The beneficial effects of the present invention are:

[0013] 1. The present invention adopts a reverse positioning mechanism to realize positioning grinding based on the ball base surface of the large end of the roller, so that the tapered roller is trimmed, ground and measured with the ball base surface of the tapered roller as the reference; and it is highly consistent with the running track of the bearing when in use; it will not only improve the accuracy level of the tapered roller bearing, but also increase the speed and service life of the tapered roller bearing.

[0014] 2. The present invention is mainly for grinding the generatrix of long-life symmetrical logarithmically trimmed tapered rollers on CNC centerless grinders, and can realize that the CNC grinding wheel dresser and CNC guide wheel dresser can use the contact point between the ball base surface and the reverse fixed mechanism as the starting point for the X-axis value and the calculation start end when dressing the grinding wheel and the guide wheel, so as to realize that the ball base surface of the tapered roller is used as the reference for grinding wheel correction, guide wheel correction, grinding and measurement, thereby improving production efficiency and inspection efficiency.

[0015] 3. The present invention makes it easy to put and take the tapered roller, so the reverse positioning mechanism is designed as a linkage structure, that is, when putting and taking the tapered roller on the grinding machine, the spherical positioning device needs to fall under the guide plate, and when grinding, the spherical positioning device will rise and contact the base surface of the tapered roller for positioning, and a reverse preload mechanism and a reverse positioning mechanism must be installed. Note: When the axial force generated by grinding is positive.

[0016] 4. The present invention enables the tapered roller to generate an axial force pointing to the operator during grinding, so that it automatically rotates and pushes the roller ball base surface to tangentially contact and position with the reverse positioning surface (consistent with the motion trajectory of the bearing when in use, the tapered roller ball base surface is tangentially contacted and positioned with the large rib cone surface). Therefore, the layout of the grinding wheel axis and the guide wheel axis of the original centerless grinder must be adjusted in the opposite direction to achieve precise tangential contact positioning.

[0017] 5. The present invention is very suitable for grinding high-precision long-life tapered rollers: the generatrix design of high-precision long-life tapered rollers is a symmetrical logarithmic generatrix. When grinding, the large end ball base surface of the tapered roller must be used as the starting end of the CNC grinding wheel corrector calibration selection surface, and the grinding wheel and guide wheel grinding surface correction must be performed to achieve the tangency of the logarithmic generatrix of the tapered roller outer diameter and the large end ball base surface of the tapered roller. Note: The logarithmic correction formula for tapered rollers is: P(X)=K*Dwe*Ln(1 / [1-(2*X / Lwe)½]), when 2*X≥Lwe, the logarithmic function does not hold.

[0018] 6. The contact positioning point of the reverse positioning mechanism of the present invention complies with the rotation direction of the tapered roller to reduce the friction resistance during grinding, thereby improving the processing quality of the tapered roller.

[0019] 7. The reverse positioning mechanism of the present invention is provided with a front positioning shaft and a rear positioning block, which can ensure the position of the positioning crank arm, thereby providing stable support for the large end spherical surface of the tapered roller.

[0020] 8. The present invention is provided with an elastic preload rod, which can be deformed under a strong force, so as to realize the function of rotating and regulating the positioning crank arm, and is easy to operate and highly efficient.

[0021] 9. The positioning crank arm of the present invention adopts the working principle of a lever, wherein the middle part is hinged on the guide plate and can rotate, and an arc surface is arranged at one end of the positioning crank arm to facilitate contact with the large end ball base surface of the tapered roller, and the two are in tangential contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the principle diagram of tapered roller grinding;

[0023] Figure 2 It is a structural schematic diagram of the reverse positioning mechanism of the tapered roller grinding device based on the large end ball base surface as the reference positioning;

[0024] Figure 3 for Figure 2 Side view of the reverse positioning mechanism shown. DETAILED DESCRIPTION

[0025] Example: See Figure 1 , Figure 2 and Figure 3 , 1-tapered roller, 2-grinding wheel, 3-guide wheel, 4-guide plate, 5-positioning crank arm, 6-rear positioning block, 7-front positioning shaft, 8-elastic preload rod, 9-handle, 10-front support shaft, 11-rear support shaft, 12-articulated shaft; 13-tangent contact point.

[0026] Figure 1 In the figure, the grinding wheel 2 and the guide wheel 3 both rotate to the right, and when they are tangent to the left and right of the center of the roller respectively, they will drive the tapered roller 1 to rotate to the left, that is, the guide wheel 3 guides the roller to rotate to the left, and the grinding wheel 2 grinds the roller to rotate to the left so that the roller can achieve friction rotation.

[0027] The tapered roller grinding method based on the large end ball base surface as the reference positioning, the technical solution is:

[0028] a. A reverse positioning mechanism is installed at the front end of the guide plate 4 of the centerless grinder. The reverse positioning mechanism includes a positioning crank arm 5. The middle part of the positioning crank arm 5 is rotatably connected to the guide plate 4 through a hinge shaft 12. An elastic preload rod 8 is arranged at one end of the positioning crank arm 5. A rear positioning block 6 and a front positioning shaft 7 are arranged on the guide plate 4. The rear positioning block 6 and the front positioning shaft 7 respectively define the positioning crank arm 5 and the elastic preload rod 8;

[0029] b. During grinding, by adjusting the elastic preload rod 8, the front positioning shaft 7 and the rear positioning block 6, the other end of the positioning arm 5 is brought into contact with the large end ball base surface of the tapered roller 1, so as to achieve positioning grinding based on the large end ball base surface of the roller, so that the tapered roller is corrected with the grinding wheel, the guide wheel, ground and measured based on the tapered roller ball base surface, and the tapered roller is highly consistent with the running track of the bearing when in use.

[0030] Preferred solution: The other end of the positioning crank arm 5 is provided with an arc surface, and is in tangential contact with the large end ball base surface of the tapered roller 1. The outer end of the elastic preload rod 8 is provided with a spherical handle 9 for easy operation. The elastic preload rod 8 is made of elastic material. The rear positioning block 6 is fixed to the guide plate 4 by connecting bolts, and its side surface is in contact with the side surface of the positioning crank arm 5. The front positioning shaft 7 is tightly matched with the positioning hole on the guide plate 4.

[0031] Since the elastic preload rod 8 has a certain elasticity, it can be pressed downward and bent outward, so as to be free from the restraint of the front positioning column 7. In addition, the elastic preload rod 8 also has a certain hardness, so as to provide support force for the tapered roller 1.

[0032] When the handle 9 is pressed and bent outward, the other end of the positioning crank arm 5 rotates downward. When the rotation height is lower than the guide plate 4, the roller can be easily taken in and out. When the grinding wheel 2 is fed, the reverse operation is performed to press the handle 9 down to the front positioning shaft 7, so that the elastic preload rod 8 is bent to generate a preload force so that the positioning tangent point of the positioning crank arm 5 is tangent to the ball base surface of the large end of the tapered roller 1, and the preload force makes the positioning surface of the positioning crank arm 5 closely contact with the reverse positioning surface of the rear positioning block 6 to achieve precise positioning.

[0033] The invention has reasonable design, convenient and simple use. It cleverly uses the anti-positioning mechanism to bear the axial force generated by the plunge grinding to realize the automatic rotation and positioning of the tapered roller. After the anti-positioning mechanism is installed on the guide plate, a new grinding method for grinding the long-life symmetrical logarithm-shaped tapered roller generatrix on the CNC centerless grinder is realized; and the X-axis value and calculation starting end of the CNC grinding wheel dresser and the CNC guide wheel dresser when dressing the grinding wheel and the guide wheel are both based on the tangent point of the spherical base surface as the starting end point, so as to realize that the grinding wheel correction, guide correction, plunge grinding, inspection and measurement are all based on the spherical base surface of the tapered roller as the common reference surface, and the production efficiency and inspection efficiency can be improved while reducing the production cost under the premise of ensuring quality.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for grinding a tapered roller based on the large end ball base surface as a reference positioning, comprising the following steps: a. A reverse positioning mechanism is installed at the front end of the guide plate of the centerless grinder, and the reverse positioning mechanism includes a positioning crank arm, the middle part of which is rotatably connected to the guide plate through a hinge shaft, one end of the positioning crank arm is provided with an elastic preload rod, and the guide plate is provided with a rear positioning block and a front positioning shaft, and the rear positioning block and the front positioning shaft respectively define the positioning crank arm and the elastic preload rod; b. During grinding, by adjusting the elastic preload rod, the front positioning shaft and the rear positioning block, the other end of the positioning arm is brought into contact with the large end ball base surface of the tapered roller, so as to achieve positioning grinding based on the large end ball base surface of the roller, so that the tapered roller is corrected with the grinding wheel, corrected with the guide wheel, ground and measured based on the tapered roller ball base surface, and the tapered roller is highly consistent with the running track of the bearing when in use.

2. The tapered roller grinding method based on the large end ball base surface as the reference positioning according to claim 1 is characterized in that: The other end of the positioning crank arm is provided with an arc surface, and is in tangential contact with the large end ball base surface of the tapered roller.

3. The tapered roller grinding method based on the large end ball base surface as the reference positioning according to claim 1 is characterized in that: The outer end of the elastic pre-tightening rod is provided with a spherical handle for easy operation, and the elastic pre-tightening rod is made of elastic material.

4. The tapered roller grinding method based on the large end ball base surface as the reference positioning according to claim 1 is characterized in that: The rear positioning block is fixed on the guide plate by connecting bolts, and its side surface is in contact with the side surface of the positioning crank arm. The front positioning shaft is tightly matched with the positioning hole on the guide plate.

5. A tapered roller grinding device based on the large end ball base surface as the reference positioning, including a positioning crank arm, characterized by: The middle part of the positioning crank arm is rotatably connected with the guide plate through a hinge shaft, one end of the positioning crank arm is provided with an elastic preload rod, the guide plate is provided with a rear positioning block and a front positioning shaft, the rear positioning block and the front positioning shaft respectively define the positioning crank arm and the elastic preload rod, the other end of the positioning crank arm contacts with the large end ball base surface of the tapered roller, and the positioning grinding is realized with the large end ball base surface of the roller as the reference, so that the tapered roller is corrected with the grinding wheel, the guide wheel, ground, and measured with the tapered roller ball base surface as the reference; and it is highly consistent with the running track of the bearing when in use; The other end of the positioning crank arm is provided with an arc surface, and is in tangential contact with the large end ball base surface of the tapered roller; The outer end of the elastic pre-tightening rod is provided with a spherical handle for easy operation, and the elastic pre-tightening rod is made of elastic material.

6. The tapered roller grinding device based on the large end ball base surface as the reference positioning according to claim 5 is characterized in that: The rear positioning block is fixed on the guide plate by connecting bolts, and its side surface is in contact with the side surface of the positioning crank arm. The front positioning shaft is tightly matched with the positioning hole on the guide plate.

Images