Grinding disk kit, grinding equipment and grinding method for finishing rolling surfaces of bearing rollers

Abstract

Disclosed is a grinding disk kit for finishing rolling surfaces of bearing rollers, including a pair of coaxial first and second grinding disks; a front face of the first grinding disk includes a group of radially distributed linear grooves and transition faces for connecting the adjacent linear grooves; a front face of the second grinding disk includes one or more helical grooves and transition faces for connecting adjacent helical grooves; one bearing roller to be machined is distributed in each linear groove corresponding to each intersection of the helical grooves and the linear grooves during grinding machining; the rolling surfaces of the bearing rollers to be machined are respectively in contact with working faces of the linear grooves and the helical grooves corresponding to each intersection; and the bearing rollers to be machined translate along the linear grooves while rotating about the own axes under the friction.

We claim: 
     
         1 . A grinding disk kit for finishing rolling surfaces of bearing rollers, comprising a pair of coaxial first grinding disk ( 21 ) and second grinding disk ( 22 ), wherein a front face ( 211 ) of the first grinding disk is arranged opposite to a front face of the second grinding disk ( 221 );
 the front face ( 211 ) of the first grinding disk comprises a group of radially distributed linear grooves ( 2111 ) and transition faces ( 2112 ) for connecting the adjacent linear grooves; the front face ( 221 ) of the second grinding disk comprises one or more helical grooves ( 2211 ) and transition faces ( 2212 ) for connecting the adjacent helical grooves; surfaces of the linear grooves ( 2111 ) comprise working faces ( 21111 ) of the linear grooves in contact with the rolling surfaces ( 32 ) of the bearing rollers to be machined during grinding machining; surfaces of the helical grooves ( 2211 ) comprise working faces ( 22111 ) of the helical grooves in contact with the bearing rollers during grinding machining;   one bearing roller ( 3 ) to be machined is distributed in each linear groove ( 2111 ) of the first grinding disk along the linear groove corresponding to each intersection of the helical grooves ( 2211 ) of the second grinding disk and the linear grooves ( 2111 ) of the first grinding disk during grinding machining; the bearing rollers are cylindrical rollers or tapered rollers; a region, corresponding to each intersection, enclosed by working faces ( 21111 ) of the linear grooves of the first grinding disk and working faces ( 22111 ) of the helical grooves of the second grinding disk is a grinding machining region; the rolling surfaces ( 32 ) of the bearing rollers to be machined are in contact with the working faces ( 21111 ) of the linear grooves and the working faces ( 22111 ) of the helical grooves, respectively; the bearing rollers ( 3 ) to be machined translate along the linear grooves ( 2111 ) while rotating about the own axes ( 31 ) under the friction driving and thrusting actions of the working faces ( 22111 ) of the helical grooves; and the rolling surfaces ( 32 ) of the bearing rollers to be machined slide relative to the working faces ( 21111 ) of the linear grooves, to realize the grinding machining for the rolling surfaces ( 32 ) of the bearing rollers to be machined.   
     
     
         2 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 1 , wherein the working faces ( 21111 ) of the linear grooves are located on scanning planes ( 21113 ) of the linear grooves; the scanning planes ( 21113 ) of the linear grooves are constant cross-section scanning planes; scanning paths of the scanning planes ( 21113 ) of the linear grooves are straight lines; generatrices of the scanning planes ( 21113 ) of the linear grooves are in normal sections ( 21114 ) of the linear grooves; the scanning paths passing through a selected point are recorded as base lines ( 21116 ) of the linear grooves; all the base lines ( 21116 ) of the linear grooves are distributed on a right circular cone face; the right circular cone face is a base face ( 214 ) of the first grinding disk; an axis of the base face ( 214 ) of the first grinding disk is an axis ( 213 ) of the first grinding disk; and the base face ( 214 ) of the first grinding disk has a cone apex angle  2 α;
 when the bearing rollers are cylindrical rollers, in the normal sections ( 21114 ) of the linear grooves, a normal section profile ( 211131 ) of the scanning planes ( 21113 ) of the linear grooves is a circular arc with a curvature radius equal to that of the rolling surfaces ( 32 ) of the cylindrical rollers to be machined; the selected point is a center of curvature of the normal section profile ( 211131 ); the base lines ( 21116 ) of the linear grooves pass through the center of curvature of the normal section profile ( 211131 ); the base lines ( 21116 ) of the linear grooves are in an axial section ( 215 ) of the first grinding disk; the axial section ( 215 ) of the first grinding disk comprising the base lines ( 21116 ) of the linear grooves is a central plane ( 21112 ) of the working faces ( 21111 ) of the linear grooves; axes ( 31 ) of the cylindrical rollers to be machined are in the central plane ( 21112 ) of the working faces of the linear grooves during grinding machining; the rolling surfaces ( 32 ) of the cylindrical rollers to be machined are in contact with the working faces ( 21111 ) of the linear grooves; and the axes ( 31 ) of the cylindrical rollers to be machined overlap with the base lines ( 21116 ) of the linear grooves; 
 when the bearing rollers are tapered rollers, in the normal sections ( 21114 ) of the linear grooves, the normal section profile ( 211131 ) of the scanning planes ( 21113 ) of the linear grooves comprises two symmetrical linear segments; an angle between the two linear segments is  2 θ; during grinding machining, the rolling surfaces ( 32 ) of the tapered rollers to be machined is in line contact with two symmetrical side faces of the working faces ( 21111 ) of the linear grooves, respectively; the tapered rollers to be machined are placed as a reference in the linear grooves ( 2111 ), and a contact relationship between the tapered rollers to be machined and the working faces ( 21111 ) of the linear grooves is the same as that during grinding machining; the selected point is a midpoint (Q) of the mapping (CD) of the rolling surfaces ( 32 ) of the tapered rollers to be machined on the own axes ( 31 ); the base lines ( 21116 ) of the linear grooves pass through the midpoint (Q) of the mapping (CD) of the rolling surfaces ( 32 ) of the tapered roller to be machined on the own axes ( 31 ); a central plane ( 21112 ) of the working faces ( 21111 ) of the linear grooves is a plane comprising a normal section profile symmetry line ( 211132 ) of the scanning planes ( 21113 ) of the linear grooves and the base lines ( 21116 ) of the linear grooves; the base lines ( 21116 ) of the linear grooves are in the axial section ( 215 ) of the first grinding disk; the central plane ( 21112 ) of the working faces ( 21111 ) of the linear grooves overlap with the axial section ( 215 ) of the first grinding disk comprising the base lines ( 21116 ) of the linear grooves; the axes ( 31 ) of the tapered rollers to be machined are in the central plane ( 21112 ) of the working faces ( 21111 ) of the linear grooves during grinding machining; the tapered rollers to be machined have a half-cone angle φ; an angle between the axes ( 31 ) of the tapered rollers to be machined and the base lines ( 21116 ) of the linear grooves is γ; and sin φ=sin γ sin θ; 
 the working faces ( 22111 ) of the helical grooves comprise a first working face ( 221111 ) and a second working face ( 221112 ); 
 when the bearing rollers are the cylindrical rollers, during grinding machining, the rolling surfaces ( 32 ) of the cylindrical rollers to be machined are in line contact with the first working face ( 221111 ), and an end-face edge fillet ( 332 ) of the cylindrical rollers to be machined is in line or point contact with the second working face ( 221112 ) under the constraints of the working faces ( 21111 ) of the linear grooves of the first grinding disk; when the bearing rollers are the tapered rollers, during grinding machining, the rolling surfaces ( 32 ) of the tapered rollers to be machined are in line contact with the first working face ( 221111 ), and a big-end sphere base face ( 342 ) or a big-end edge fillet ( 341 ) or a small-end edge fillet ( 331 ) of the tapered rollers to be machined is in line contact with the second working face ( 221112 ) under the constraints of the working faces ( 21111 ) of the linear grooves of the first grinding disk; 
 the first working face ( 221111 ) and the second working face ( 221112 ) are respectively located on a first scanning plane ( 221121 ) and a second scanning plane ( 221122 ); both the first scanning plane ( 221121 ) and the second scanning plane ( 221122 ) are constant cross-section scanning planes; the bearing rollers to be machined are placed as a reference in the helical grooves ( 2211 ), and a contact relationship between the bearing rollers to be machined and the working faces ( 22111 ) of the helical grooves is the same as that during grinding machining; the scanning paths of the first scanning plane ( 221121 ) and the second scanning plane ( 221122 ) are right circular conical helices, which pass through the midpoint (Q) of the mapping (CD) of the rolling surfaces ( 32 ) of the bearing rollers to be machined on the own axes ( 31 ) and are distributed on a right circular cone face; the right circular conical helices are the base lines ( 22116 ) of the helical grooves; the right circular cone face is a base face ( 224 ) of the second grinding disk; and the axis of the base face ( 224 ) of the second grinding disk is an axis ( 223 ) of the second grinding disk; 
 the generatrices of the first scanning plane ( 221121 ) and the second scanning plane ( 221122 ) are both in the axial section ( 225 ) of the second grinding disk; 
 the base face ( 224 ) of the second grinding disk has a cone apex angle  2 β; 
 the cone apex angle of the base face ( 214 ) of the first grinding disk and the cone apex angle of the base face ( 224 ) of the second grinding disk satisfy the following relationship:  2 α+ 2 β=360°; 
 when  2 α= 2 β=180°, the axis ( 213 ) of the first grinding disk is perpendicular to the base face ( 214 ) of the first grinding disk; the axis ( 223 ) of the second grinding disk is perpendicular to the base face ( 224 ) of the second grinding disk; the base lines ( 21116 ) of the linear grooves may be in or out of the axial section ( 215 ) of the first grinding disk; and when the base lines ( 21116 ) of the linear grooves are out of the axial section ( 215 ) of the first grinding disk, the central plane ( 21112 ) of the working faces ( 21111 ) of the linear grooves is parallel to the axis ( 213 ) of the first grinding disk. 
 
     
     
         3 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 2 , wherein when the bearing rollers are the cylindrical rollers, the base lines ( 22116 ) of the helical grooves are right circular conical equiangular helices ( 221161 ) or right circular conical non-equiangular helices ( 221162 ); and when the bearing rollers are the tapered rollers, the base lines ( 22116 ) of the helical grooves are right circular conical equiangular helices ( 221161 ). 
     
     
         4 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 2 , wherein when the bearing rollers are the tapered rollers and the rolling surfaces ( 32 ) of the tapered rollers are designed with convexity, the normal section profile ( 211131 ) of the scanning planes of the linear grooves, where the working faces ( 21111 ) of the linear grooves are adapted to the rolling surfaces, is modified according to a convexity curve of the rolling surfaces ( 32 ) of the tapered rollers. 
     
     
         5 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 3 , wherein when the bearing rollers are the tapered rollers and the rolling surfaces ( 32 ) of the tapered rollers are designed with convexity, the normal section profile ( 211131 ) of the scanning planes of the linear grooves, where the working faces ( 21111 ) of the linear grooves are adapted to the rolling surfaces, is modified according to a convexity curve of the rolling surfaces ( 32 ) of the tapered rollers. 
     
     
         6 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 2 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; a base body ( 220 ) of the second grinding disk is made of a magnetic conductive material; an annular magnetic structure ( 226 ) is embedded inside the base body ( 220 ) of the second grinding disk; a group of annular band-shaped or helical band-shaped non-magnetic conductive materials ( 228 ) are embedded in the front face ( 221 ) of the second grinding disk; the magnetic conductive material of the base body ( 220 ) of the second grinding disk and the embedded annular band-shaped or helical band-shaped non-magnetic conductive materials ( 228 ) are closely connected on the front face ( 221 ) of the second grinding disk and form the front face ( 221 ) of the second grinding disk together. 
     
     
         7 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 2 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; the base body ( 220 ) of the second grinding disk is made of the magnetic conductive material; the annular magnetic structure ( 226 ) is embedded in the base body ( 220 ) of the second grinding disk; and a group of annular grooves or helical grooves are formed in the front face ( 221 ) of the second grinding disk. 
     
     
         8 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 2 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; the base body ( 220 ) of the second grinding disk is made of the magnetic conductive material; the annular magnetic structure ( 226 ) is embedded in the base body ( 220 ) of the second grinding disk; and a group of annular grooves or helical grooves are formed in one side of an inner cavity of the base body ( 220 ) of the second grinding disk opposite to the front face ( 221 ) of the second grinding disk. 
     
     
         9 . A grinding equipment for finishing rolling surfaces of bearing rollers, comprising a main machine, a part of a roller circulating system outside the grinding disk and the grinding disk kit of  claim 2 , wherein
 the main machine comprises a base ( 11 ), a column ( 12 ), a beam ( 13 ), a sliding table ( 14 ), an upper pallet ( 15 ), a lower pallet ( 16 ), an axial loading device ( 17 ) and a spindle device ( 18 );   a frame of the main machine is composed of the base ( 11 ), the column ( 12 ) and the beam ( 13 );   the first grinding disk ( 21 ) of the grinding disk kit is connected with the lower pallet ( 16 ); and the second grinding disk ( 22 ) of the grinding disk kit is connected with the upper pallet ( 15 );   the sliding table ( 14 ) is connected with the beam ( 13 ) through the axial loading device ( 17 ); the column ( 12 ) can also serve as a guide component to play a role of guiding the sliding table ( 14 ) to move linearly along the axis ( 223 ) of the second grinding disk; the sliding table ( 14 ) moves linearly along the axis ( 223 ) of the second grinding disk under the driving of the axial loading device ( 17 ) and the constraints of the column ( 12 ) and other guide components;   the spindle device ( 18 ) is configured to drive the first grinding disk ( 21 ) or the second grinding disk ( 22 ) to rotate about the own axis;   the part of the roller circulating system outside the grinding disk comprises roller collecting devices ( 41 ), roller conveying systems ( 43 ), roller sorting mechanisms ( 44 ) and roller feeding mechanisms ( 45 );   the roller collecting device ( 41 ) is arranged at an outlet ( 21119 ) of each linear groove of the first grinding disk, and configured to collect the bearing roller ( 3 ) to be machined leaving the grinding machining region enclosed by the working faces ( 21111 ) of the linear grooves and the working faces ( 22111 ) of the helical grooves from the outlet ( 21119 ) of each linear groove;   the roller conveying systems ( 43 ) are configured to convey the bearing rollers ( 3 ) to be machined from the roller collecting devices ( 41 ) to the roller feeding mechanisms ( 45 );   the roller sorting mechanisms ( 44 ) are arranged at front ends of the roller feeding mechanisms ( 45 ); based on different types of the bearing rollers, the roller sorting mechanisms ( 44 ) have functions as follows:   1) when the bearing rollers are the cylindrical rollers, the roller sorting mechanisms ( 44 ) are configured to adjust the axes ( 31 ) of the cylindrical rollers to be machined to a direction required by the roller feeding mechanisms ( 45 );   2) when the bearing rollers are the tapered rollers, the roller sorting mechanisms ( 44 ) are configured to adjust the axes ( 31 ) of the tapered rollers to be machined to the direction required by the roller feeding mechanisms ( 45 ), and adjust the direction of small ends of the tapered rollers to be machined to a direction adapted to an axial section profile of the scanning planes ( 22112 ) of helical grooves, wherein the working faces ( 22111 ) of the helical grooves of the second grinding disk are located at the scanning planes ( 22112 ) of the helical grooves;   during grinding machining, the grinding disk kit can rotate in two modes; in a first mode, the first grinding disk ( 21 ) rotates about the own axis, and the second grinding disk ( 22 ) does not rotate; and in a second mode, the first grinding disk ( 21 ) does not rotate, and the second grinding disk ( 22 ) rotates about the own axis;   the main machine has three configurations: a first main machine configuration for rotating the grinding disk kit in the first mode, a second main machine configuration for rotating the grinding disk kit in the second mode, and a third main machine configuration suitable for rotating the grinding disk kit in the first mode and the second mode;   based on different configurations of the main machine, the relative motion of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) as well as positions and functions of the roller feeding mechanisms ( 45 ) in the grinding equipment are shown as follows:   in correspondence to the first main machine configuration:   the spindle device ( 18 ) is mounted on the base ( 11 ) and drives the first grinding disk ( 21 ) to rotate about the own axis by the connected lower pallet ( 16 ); the upper pallet ( 15 ) is connected with the sliding table ( 14 );   the first grinding disk ( 21 ) rotates about the own axis during grinding machining; the sliding table ( 14 ), together with the connected upper pallet ( 15 ) and the second grinding disk ( 22 ) connected with the upper pallet, approaches the first grinding disk ( 21 ) along the axis ( 223 ) of the second grinding disk under the constraints of the column ( 12 ) or other guide components, and applies a working pressure to the bearing rollers ( 3 ) to be machined distributed in the linear grooves ( 2111 ) of the first grinding disk ( 21 );   the roller feeding mechanisms ( 45 ) are respectively mounted at an inlet ( 22118 ) of each helical groove of the second grinding disk, and configured to push one bearing roller ( 3 ) to be machined into the inlet ( 22118 ) of one linear groove when the inlet ( 21118 ) of any linear groove of the first grinding disk intersects the inlet ( 22118 ) of one helical groove;   in correspondence to the second main machine configuration:   the spindle device ( 18 ) is mounted on the sliding table ( 14 ) and drives the second grinding disk ( 22 ) to rotate about the own axis by the connected upper pallet ( 15 ); the lower pallet ( 16 ) is mounted on the base ( 11 );   the second grinding disk ( 22 ) rotates about the own axis during grinding machining; the sliding table ( 14 ), together with the spindle device ( 18 ), the upper pallet ( 15 ) connected with the spindle device ( 18 ) and the second grinding disk ( 22 ) connected with the upper pallet ( 15 ), approaches the first grinding disk ( 21 ) along the axis ( 223 ) of the second grinding disk under the constraints of the column ( 12 ) or other guide components, and applies a working pressure to the bearing rollers ( 3 ) to be machined distributed in the linear grooves ( 2111 ) of the first grinding disk ( 21 );   the roller feeding mechanisms ( 45 ) are respectively mounted at an inlet ( 21118 ) of each linear groove of the first grinding disk, and configured to push one bearing roller ( 3 ) to be machined into the inlet ( 21118 ) of one linear groove when the inlet ( 22118 ) of any helical groove of the second grinding disk intersects the inlet of one linear groove;   in correspondence to the third main machine configuration:   two spindle devices ( 18 ) are provided, wherein one spindle device ( 18 ) is mounted on the base ( 11 ) and drives the first grinding disk ( 21 ) to rotate about the own axis by the connected lower pallet ( 16 ); the other spindle device ( 18 ) is mounted on the sliding table ( 14 ) and drives the second grinding disk ( 22 ) to rotate about the own axis by the connected upper pallet ( 15 ); the two spindle devices ( 18 ) are provided with locking mechanisms; only one of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) is allowed to rotate at a time while the other grinding disk is in a circumferentially locked state;   when the grinding disk kit of the grinding equipment rotates in the first mode for grinding machining, the relative motion of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) is the same as that in the first main machine configuration, and the positions and functions of the roller feeding mechanisms ( 45 ) in the equipment are the same as those in the first main machine configuration; and when the grinding disk kit of the grinding equipment rotates in the second mode for grinding machining, the relative motion of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) is the same as that in the second main machine configuration, and the positions and functions of the roller feeding mechanisms ( 45 ) in the equipment are the same as those in the second main machine configuration.   
     
     
         10 . The grinding equipment for finishing rolling surfaces of bearing rollers according to  claim 9 , which is different from the grinding equipment of  claim 9  in that:
 the grinding disk kit of  claim 6  is used as the grinding disk kit; 
 the part of the roller circulating system outside the grinding disk also comprises roller demagnetizing devices ( 42 ); the roller demagnetizing devices ( 42 ) are arranged in the roller conveying systems ( 43 ) in a part of a roller circulating path outside the grinding disk or in front of the roller conveying systems ( 43 ) and configured to demagnetize the ferromagnetic bearing rollers ( 3 ) to be machined, wherein the ferromagnetic bearing rollers to be machined are magnetized by a magnetic field of an annular magnetic structure ( 226 ) inside the base body of the second grinding disk. 
 
     
     
         11 . A grinding method for finishing rolling surfaces of bearing rollers, using the grinding equipment of  claim 9  and comprising the following steps:
 step 1, making the second grinding disk ( 22 ) approach the first grinding disk ( 21 ) along the own axis until a space of each grinding machining region enclosed by the working faces ( 21111 ) of the linear grooves of the first grinding disk and the working faces ( 22111 ) of the helical grooves of the second grinding disk can just accommodate one bearing roller to be machined; 
 step 2, in correspondence to the first rotation mode of the grinding disk kit, rotating the first grinding disk ( 21 ) about the own axis relative to the second grinding disk ( 22 ) at a low speed of 1-10 rpm; and in correspondence to the second rotation mode of the grinding disk kit, rotating the second grinding disk ( 22 ) about the own axis relative to the first grinding disk ( 21 ) at a low speed of 1-10 rpm; 
 step 3, starting the roller conveying systems ( 43 ), the roller sorting mechanisms ( 44 ) and the roller feeding mechanisms ( 45 ); adjusting the feeding speed of the roller feeding mechanisms ( 45 ) to be matched with a relative rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ); and adjusting the conveying speed of the roller conveying systems ( 43 ) and the sorting speed of the roller sorting mechanisms ( 44 ) to be matched with the feeding speed of the roller feeding mechanisms ( 45 ), thereby establishing a circulation of the linear feeding of the bearing rollers ( 3 ) to be machined along the base lines ( 21116 ) of the linear grooves between the first grinding disk ( 21 ) and the second grinding disk ( 22 ) as well as the collecting, conveying, sorting and feeding through the part of the roller circulating system outside the grinding disk; 
 step 4, adjusting the relative rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) to a relative working rotation speed of 5-60 rpm, adjusting the feeding speed of the roller feeding mechanisms ( 45 ) to a working feeding speed so as to match with the relative working rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ), adjusting the conveying speed of the roller conveying systems ( 43 ) and the sorting speed of the roller sorting mechanisms ( 44 ) so that the bearing rollers ( 3 ) to be machined at each of the roller collecting devices ( 41 ), the roller conveying systems ( 43 ), the roller sorting mechanisms ( 44 ) and the roller feeding mechanisms ( 45 ) in the part of the roller circulating system outside the grinding disk are matched in stock and smooth and orderly in circulation; 
 step 5, filling the grinding machining regions with grinding fluid; 
 step 6, comprising: 
 1) when the bearing rollers are the cylindrical rollers, making the second grinding disk ( 22 ) further approach the first grinding disk ( 21 ) along the own axis, so that the rolling surfaces ( 32 ) of the cylindrical rollers to be machined in the grinding machining regions are in face contact with the working faces ( 21111 ) of the linear grooves of the first grinding disk and in line contact with the first working faces ( 221111 ) of the helical grooves of the second grinding disk, respectively; when the bearing rollers are the tapered rollers, making the second grinding disk ( 22 ) further approach the first grinding disk ( 21 ) along the own axis, so that the rolling surfaces ( 32 ) of the tapered rollers to be machined in the grinding machining regions are in line contact with two symmetrical side faces of the working faces ( 21111 ) of the linear grooves of the first grinding disk and the first working faces ( 221111 ) of the helical grooves of the second grinding disk, and big-end sphere base faces ( 342 ) or big-end edge fillets ( 341 ) or small-end edge fillets ( 331 ) of the tapered rollers to be machined are in line contact with the second working faces ( 221112 ) of the helical grooves of the second grinding disk; 
 2) applying an average initial working pressure of 0.5-2 N to all the bearing rollers ( 3 ) to be machined distributed in the grinding machining region; driving the bearing rollers ( 3 ) to be machined by the friction of the working faces ( 22111 ) of the helical grooves of the second grinding disk to continuously rotate about the own axes ( 31 ); meanwhile, continuously pushing the bearing rollers ( 3 ) to be machined by the working faces ( 22111 ) of the helical grooves to be fed linearly along the base lines ( 21116 ) of the linear grooves of the first grinding disk; and starting to grind the rolling surfaces ( 32 ) of the bearing rollers to be machined by the working faces ( 21111 ) of the linear grooves of the first grinding disk and the first working faces ( 221111 ) of the helical grooves of the second grinding disk; 
 step 7, with the stable operation of grinding machining process, gradually increasing the working pressure of each bearing roller ( 3 ) to be machined distributed in the grinding machining region to a normal working pressure of 2-50 N; making the bearing rollers ( 3 ) to be machined continuously maintain the contact with the working faces ( 21111 ) of the linear grooves of the first grinding disk and the working faces ( 22111 ) of the helical grooves of the second grinding disk in the step 6, rotate about the own axes ( 31 ) and linearly fed along the base lines ( 21116 ) of the linear grooves; and continuously grinding the rolling surfaces ( 32 ) by the working faces ( 21111 ) of the linear grooves of the first grinding disk and the first working faces ( 221111 ) of the helical grooves of the second grinding disk; 
 step 8, after a period of grinding machining, sampling the bearing rollers ( 3 ) to be machined; if the surface quality, the shape precision and the dimensional uniformity of the rolling surface ( 32 ) of the sampled bearing rollers to be machined have not yet met technical requirements, continuing the grinding machining in the step 8; and if the surface quality, the shape precision and the dimensional uniformity of the rolling surface ( 32 ) of the sampled bearing rollers to be machined meet the technical requirements, entering into step 9; and 
 step 9, gradually reducing the working pressure to zero eventually; stopping the operation of the roller feeding mechanisms ( 45 ), the roller conveying systems ( 43 ) and the roller finishing mechanisms ( 44 ); adjusting the relative rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) to zero; stopping filling the grinding machining regions with the grinding fluid; and making the second grinding disk ( 22 ) return to a non-working position along the own axis. 
 
     
     
         12 . A grinding method for finishing rolling surfaces of bearing rollers, using the grinding equipment of  claim 10 , used for machining rolling surfaces of ferromagnetic bearing rollers and comprising the following steps:
 step 1, making the second grinding disk ( 22 ) approach the first grinding disk ( 21 ) along the own axis until a space of each grinding machining region enclosed by the working faces ( 21111 ) of the linear grooves of the first grinding disk and the working faces ( 22111 ) of the helical grooves of the second grinding disk can just accommodate one bearing roller to be machined;   step 2, in correspondence to the first rotation mode of the grinding disk kit, rotating the first grinding disk ( 21 ) about the own axis relative to the second grinding disk ( 22 ) at a low speed of 1-10 rpm; and in correspondence to the second rotation mode of the grinding disk kit, rotating the second grinding disk ( 22 ) about the own axis relative to the first grinding disk ( 21 ) at a low speed of 1-10 rpm;   step 3, starting the roller demagnetizing devices ( 42 ), the roller conveying systems ( 43 ), the roller sorting mechanisms ( 44 ) and the roller feeding mechanisms ( 45 ); adjusting the feeding speed of the roller feeding mechanisms ( 45 ) to be matched with the relative rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ); and adjusting the conveying speed of the roller conveying systems ( 43  and the sorting speed of the roller sorting mechanisms ( 44 ) to be matched with the feeding speed of the roller feeding mechanisms ( 45 ), thereby establishing a circulation of the linear feeding of the bearing rollers ( 3 ) to be machined along the base lines ( 21116 ) of the linear grooves between the first grinding disk ( 21 ) and the second grinding disk ( 22 ) as well as the collecting, conveying, sorting and feeding through the part of the roller circulating system outside the grinding disk;   step 4, adjusting the relative rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) to a relative working rotation speed of 5-60 rpm, adjusting the feeding speed of the roller feeding mechanisms ( 45 ) to a working feeding speed so as to match with the relative working rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ), adjusting the conveying speed of the roller conveying systems ( 43 ) and the sorting speed of the roller sorting mechanisms ( 44 ) so that the bearing rollers ( 3 ) to be machined at each of the roller collecting devices ( 41 ), the roller conveying systems ( 43 ), the roller sorting mechanisms ( 44 ) and the roller feeding mechanisms ( 45 ) in the part of the roller circulating system outside the grinding disk are matched in stock and smooth and orderly in circulation;   step 5, filling the grinding machining regions with grinding fluid;   step 6, comprising:   1) allowing the annular magnetic structure ( 226 ) inside the base body of the second grinding disk to enter into a working state; when the bearing rollers are the cylindrical rollers, making the second grinding disk ( 22 ) further approach the first grinding disk ( 21 ) along the own axis, so that the rolling surfaces ( 32 ) of the cylindrical rollers to be machined in the grinding machining regions are in face contact with the working faces ( 21111 ) of the linear grooves of the first grinding disk and in line contact with the first working faces ( 221111 ) of the helical grooves of the second grinding disk, respectively; when the bearing rollers are the tapered rollers, making the second grinding disk ( 22 ) further approach the first grinding disk ( 21 ) along the own axis, so that the rolling surfaces ( 32 ) of the tapered rollers to be machined in the grinding machining regions are in line contact with two symmetrical side faces of the working faces ( 21111 ) of the linear grooves of the first grinding disk and the first working faces ( 221111 ) of the helical grooves of the second grinding disk, and the big-end sphere base faces ( 342 ) or the big-end edge fillets ( 341 ) or the small-end edge fillets ( 331 ) of the tapered rollers to be machined are in line contact with the second working faces ( 221112 ) of the helical grooves of the second grinding disk;   2) applying an average initial working pressure of 0.5-2 N to all the bearing rollers ( 3 ) to be machined distributed in the grinding machining regions; adjusting a magnetic field strength of the annular magnetic structure ( 226 ), so that a sliding frictional driving moment generated by the working faces ( 22111 ) of the helical grooves of the second grinding disk when the bearing rollers ( 3 ) to be machined rotate about the own axes ( 31 ) is greater than a sliding frictional resistance moment generated by the working faces ( 21111 ) of the linear grooves of the first grinding disk when the bearing rollers ( 3 ) to be machined rotate about the own axes ( 31 ), thereby driving the bearing rollers ( 3 ) to be machined continuously rotate about the own axes ( 31 ); meanwhile, continuously pushing the bearing rollers ( 3 ) to be machined by the working faces ( 22111 ) of the helical grooves to be fed linearly along the base lines ( 21116 ) of the linear grooves of the first grinding disk; and starting to grind the rolling surfaces ( 32 ) of the bearing rollers to be machined by the working faces ( 21111 ) of the linear grooves of the first grinding disk and the first working faces ( 221111 ) of the helical grooves of the second grinding disk;   step 7, with the stable operation of grinding machining process, gradually increasing the working pressure of each bearing roller ( 3 ) to be machined distributed in the grinding machining region to a normal working pressure of 2-50 N; making the bearing rollers ( 3 ) to be machined continuously maintain the contact with the working faces ( 21111 ) of the linear grooves of the first grinding disk and the working faces ( 22111 ) of the helical grooves of the second grinding disk in the step 6, rotate about the own axes ( 31 ) and linearly fed along the base lines ( 21116 ) of the linear grooves; and continuously grinding the rolling surfaces ( 32 ) by the working faces ( 21111 ) of the linear grooves of the first grinding disk and the first working faces ( 221111 ) of the helical grooves of the second grinding disk;   step 8, after a period of grinding machining, sampling the bearing rollers ( 3 ) to be machined; if the surface quality, the shape precision and the dimensional uniformity of the rolling surface ( 32 ) of the sampled bearing rollers to be machined have not yet met technical requirements, continuing the grinding machining in the step 8; and if the surface quality, the shape precision and the dimensional uniformity of the rolling surface ( 32 ) of the sampled bearing rollers to be machined meet the technical requirements, entering into step 9; and   step 9, gradually reducing the working pressure to zero eventually; stopping the operation of the roller feeding mechanisms ( 45 ), the roller conveying systems ( 43 ) and the roller finishing mechanisms ( 44 ); adjusting the relative rotation speed of the first grinding disk ( 21 ) and the second grinding disk ( 22 ) to zero; switching the annular magnetic structure ( 226 ) to a non-working state for stopping the operation of the roller demagnetizing devices ( 42 ); stopping filling the grinding machining regions with the grinding fluid; and making the second grinding disk ( 22 ) return to the non-working position along the own axis.   
     
     
         13 . The grinding method for finishing rolling surfaces of bearing rollers according to  claim 12 , wherein the magnetic structure is arranged inside the second grinding disk ( 22 ) of the grinding disk kit in the adopted grinding equipment in one of the following two cases:
 case 1: when the ferromagnetic bearing rollers ( 3 ) to be machined are ground by a fixed abrasive grain grinding mode, the magnetic structure is arranged inside the second grinding disk ( 22 ); the magnetic field strength of the magnetic structure is adjusted, so that the sliding frictional driving moment generated by the working faces ( 22111 ) of the helical grooves of the second grinding disk when the ferromagnetic bearing rollers ( 3 ) to be machined rotate about the own axes ( 31 ) is greater than the sliding frictional resistance moment generated by the working faces ( 21111 ) of the linear grooves of the first grinding disk when the ferromagnetic bearing rollers ( 3 ) to be machined rotate about the own axes ( 31 ), thereby driving the ferromagnetic bearing rollers ( 3 ) to be machined to continuously rotate about the own axes ( 31 );   case 2: when the ferromagnetic bearing rollers ( 3 ) to be machined are ground by a free abrasive grain grinding mode, the magnetic structure is arranged inside the second grinding disk ( 22 ) to increase the sliding frictional driving moment generated by the working faces ( 22111 ) of the helical grooves of the second grinding disk when the ferromagnetic bearing rollers ( 3 ) to be machined rotate about the own axes ( 31 ), so that the ferromagnetic bearing rollers ( 3 ) to be machined can continuously rotate about the own axes ( 31 ) without being affected by the matching of materials of the working faces ( 21111 ) of the linear grooves of the first grinding disk and the working faces ( 22111 ) of the helical grooves of the second grinding disk.   
     
     
         14 . The grinding method for finishing rolling surfaces of bearing rollers according to  claim 11 , wherein before the first grinding disk ( 21 ) and the second grinding disk ( 22 ) are used for the first time, the working faces ( 21111 ) of the linear grooves of the first grinding disk and the working faces ( 22111 ) of the helical grooves of the second grinding disk are ground by the bearing rollers ( 3 ) to be machined with the same geometric parameters; the grinding-in method is the same as the grinding method of the bearing rollers ( 3 ) to be machined; for the step 8, the bearing rollers ( 3 ) to be machined involved in grinding-in are sampled; when the surface quality, the shape precision and the dimensional uniformity of the rolling surfaces ( 32 ) of the sampled bearing rollers to be machined meet the technical requirements, the grinding-in process enters into step 9; otherwise, the step 8 is continued. 
     
     
         15 . The grinding method for finishing rolling surfaces of bearing rollers according to  claim 12 , wherein before the first grinding disk ( 21 ) and the second grinding disk ( 22 ) are used for the first time, the working faces ( 21111 ) of the linear grooves of the first grinding disk and the working faces ( 22111 ) of the helical grooves of the second grinding disk are ground by the bearing rollers ( 3 ) to be machined with the same geometric parameters; the grinding-in method is the same as the grinding method of the bearing rollers ( 3 ) to be machined; for the step 8, the bearing rollers ( 3 ) to be machined involved in grinding-in are sampled; when the surface quality, the shape precision and the dimensional uniformity of the rolling surfaces ( 32 ) of the sampled bearing rollers to be machined meet the technical requirements, the grinding-in process enters into step 9; otherwise, the step 8 is continued. 
     
     
         16 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 3 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; a base body ( 220 ) of the second grinding disk is made of a magnetic conductive material; an annular magnetic structure ( 226 ) is embedded inside the base body ( 220 ) of the second grinding disk; a group of annular band-shaped or helical band-shaped non-magnetic conductive materials ( 228 ) are embedded in the front face ( 221 ) of the second grinding disk; the magnetic conductive material of the base body ( 220 ) of the second grinding disk and the embedded annular band-shaped or helical band-shaped non-magnetic conductive materials ( 228 ) are closely connected on the front face ( 221 ) of the second grinding disk and form the front face ( 221 ) of the second grinding disk together. 
     
     
         17 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 3 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; the base body ( 220 ) of the second grinding disk is made of the magnetic conductive material; the annular magnetic structure ( 226 ) is embedded in the base body ( 220 ) of the second grinding disk; and a group of annular grooves or helical grooves are formed in the front face ( 221 ) of the second grinding disk. 
     
     
         18 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 3 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; the base body ( 220 ) of the second grinding disk is made of the magnetic conductive material; the annular magnetic structure ( 226 ) is embedded in the base body ( 220 ) of the second grinding disk; and a group of annular grooves or helical grooves are formed in one side of an inner cavity of the base body ( 220 ) of the second grinding disk opposite to the front face ( 221 ) of the second grinding disk. 
     
     
         19 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 4 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; a base body ( 220 ) of the second grinding disk is made of a magnetic conductive material; an annular magnetic structure ( 226 ) is embedded inside the base body ( 220 ) of the second grinding disk; a group of annular band-shaped or helical band-shaped non-magnetic conductive materials ( 228 ) are embedded in the front face ( 221 ) of the second grinding disk; the magnetic conductive material of the base body ( 220 ) of the second grinding disk and the embedded annular band-shaped or helical band-shaped non-magnetic conductive materials ( 228 ) are closely connected on the front face ( 221 ) of the second grinding disk and form the front face ( 221 ) of the second grinding disk together. 
     
     
         20 . The grinding disk kit for finishing rolling surfaces of bearing rollers according to  claim 4 , wherein the grinding disk kit is used for machining rolling surfaces of ferromagnetic bearing rollers; the base body ( 220 ) of the second grinding disk is made of the magnetic conductive material; the annular magnetic structure ( 226 ) is embedded in the base body ( 220 ) of the second grinding disk; and a group of annular grooves or helical grooves are formed in the front face ( 221 ) of the second grinding disk.