Abstract:
A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc&#39;s working face is planar; the second grinding disc&#39;s surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller&#39;s cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application No. PCT/CN2015/095395 with a filing date of Nov. 24, 2015, designating the United States, now pending, and further claims priority to Chinese Patent. Application No. 201410784413.3 with a filing date of Dec. 16, 2014. The content of the aforementioned application, including any intervening amendments thereto, are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a technical field of precision machining on excircle surfaces of high precision cylindrical components, and more particularly to an excircle surface grinding device for a cylindrical-component and a method thereof. 
     BACKGROUND OF THE PRESENT INVENTION 
     Cylindrical roller bearings are widely used in various types of rotating machines. As a cylindrical roller is an important component of the cylindrical roller bearing, excircle surfaces machining precision of the cylindrical roller directly impacts the performance of the cylindrical roller bearings. Main methods of precision machining on excircle surfaces of cylindrical components include super-finishing methods and double-disc planetary grinding methods. 
     The super-finishing method is a micro finishing method, which can achieve micro cutting effects, by using a fine-grained whetstone as a grinding tool, such that the whetstone may apply load on a workpiece and perform a low-speed axial movement as well as a micro-reciprocating vibration relative to the workpiece. At present, a mostly used method of precision machining on excircle surfaces of the cylindrical roller is a through-feed centerless super-finishing method, which involves devices consisting of two guide rollers and a super-fine head assembled with a whetstone, the guide roller supporting and driving the workpiece to perform a low-speed spiral movement, the super-fine head applying a comparative low pressure to press the whetstone to the workpiece, the whetstone achieving a surface contact with the workpiece, and at the same time the whetstone performing a high-frequency vibration along an axial direction. During the process of the through-feed centerless super-finishing method, cylindrical rollers of successively penetrate processing areas and subject to be superfinished by the whetstone, and until all the cylindrical rollers have passed through the processing area for several times, a certain super-finishing process (rough finishing process, Fine finishing process, or super finishing process) ends. The through-feed centerless super-finishing method can improve the surface roughness of the workpiece (the through-feed centerless super-finishing method usually may obtain an accuracy up to Ra 0.025 μm), remove a surface degenerating layer formed by a prior process, and improve a roundness of the workpiece. Except for wear conditions of the whetstone and the super finishing roller, as well as differences of the cylindrical roller itself, each cylindrical roller share common super finishing conditions and parameters. 
     However, due to the limitations of processing principles, the super-finishing method involves following technical defects. In one aspect, variations of wear conditions of the whetstone and the super finishing roller are unfavorable for improving cylindrical surface size accuracy and shape accuracy of the cylindrical roller; in the other aspect, as in the through-feed centerless super-finishing method, only a limited number of cylindrical rollers are processed at the same time, and material removal amounts therein are almost independent of the difference between diameter thereof with that of the other cylindrical rollers of the same batch, so the through-feed centerless super-finishing method cannot obviously reduce the diameter difference of the cylindrical rollers. The above two aspects may lead to a slow improvement on excircle surface finishing precisions (shape accuracy and dimensional consistency) of the workpiece, a long processing cycle, and a high cost. 
     The main structure of a double-disc planetary cylindrical-component grinding device includes an upper grinding disc, a lower grinding disc, a planetary wheel retainer, an outer ring gear and an inner ring gear. The upper grinding disc and the lower grinding disc are coaxially arranged and respectively rotate independently, the upper plate grinding disc functioning to apply pressure. The planetary wheel retainer is placed between the inner ring gear and the outer ring gear, and a cylindrical roller is placed in a hole of the retainer, with the hole radically distributed on a surface of the retainer. During a grinding process, the retainer performs a revolution around a center of the grinding disc as well as a self rotation, under the effect of the upper and lower discs as well as the retainer, while the cylindrical roller performs a revolution around a center of the retainer and at the same time a rotation around an axis itself, thus involving a complicated spatial motion. A micro material removal is achieved under an effect of grinding solutions between the upper and lower grinding discs. Double-disc planetary cylindrical components grinding device can achieve an excircle surface of cylindrical workpiece with a high precision, for example, for a workpiece with a length of 30˜40 mm, after a super-finishing of a double-disc grinding machine, a roundness error of less than 0.001 mm may be achieved, a vertical section diameter consistency may be less than 0.002 mm, and a surface roughness is less than Ra 0.025 μm. However, the double-disc grinding machine can only be used for excircle super-finishing on small batch (dozens to hundreds) of cylindrical workpiece. For the large volume of bearing roller demand, it is difficult for the double-disc planetary grinding method to meet. 
     It can be seen that there is an inherent lack of processing precision when the excircle surface of the cylindrical workpiece is processed by the through-feed centerless super-finishing method, while the double-disc grinding method cannot meet the demand of a mass production, and thus there is an urgent need for a super-finishing device for excircle surface of the cylindrical component, which may achieve a high processing precision and a mass production, so as to meet requirements of the high precision cylindrical roller bearing on the processing precision of excircle surfaces of the cylindrical rollers, as well as the demand of production scales. 
     SUMMARY OF PRESENT INVENTION 
     Aiming at the problems in the prior art, a cylindrical-component grinding device and a grinding method using the same are provided in the present invention. The invention has the ability to meet demands of a mass production, to achieve a large removal of materials at a high position, and a small removal of that at a low position, and to realize a large material removal on the cylindrical surface of the cylindrical roller with a large diameter, and a small material removal on the cylindrical surface of the cylindrical roller with a small diameter, so as to improve the shape accuracy and dimensional consistency of cylindrical surfaces of the cylindrical roller, to enhance surface processing efficiencies of the cylindrical components (i.e. the cylindrical roller), and to reduce processing costs. 
     In order to solve the above technical problems, a cylindrical-component grinding device is provided in the invention, including a loading apparatus, a power system; and a workpiece advancing apparatus, a grinding disc apparatus, a workpiece and grinding fluid separating apparatus, a workpiece cleaning apparatus and a workpiece mixing apparatus, which are all connected to a workpiece conveying apparatus in sequence, the loading apparatus configured for loading the grinding disc apparatus, the power system configured for driving the grinding disc apparatus, wherein: the grinding disc apparatus comprises a first grinding disc and a second grinding disc, the second grinding disc and the first grinding disc rotating relative to each other, the second grinding disc having a rotation axis OO′ relative to the first grinding disc, a surface of the first grinding disc, opposite to the second grinding disc is planar, which is a working surface of the first grinding disc, and a set of radial straight grooves are provided on a surface of the second grinding disc opposite to the first grinding disc, the straight groove having a groove surface functioning as a working face of the second grinding disc, the working face of the second grinding disc having a cross-section outline in an arcuate shape or a V shape or a V shape with an arc; during grinding process, a processing workpiece is arranged in the straight groove along a groove extending direction, and meanwhile, an outer cylindrical surface of the processing workpiece contacts with the working face of the second grinding disc; the straight groove has a reference plane, a plane that passes through an axis/of the processing workpiece arranged in the straight groove, and is perpendicular to the working face of the first grinding disc; there is art angle θ between a normal plane at a contacting point or a midpoint of a contacting arc between the processing workpiece and the straight groove, and the reference plane of the straight groove, the angle θ ranging in 30˜60°; one end of the straight groove close to a center of the second grinding disc is a propulsion port, and the other end of the straight groove is a discharge outlet; an eccentric distance e exists between the reference plane of the straight groove and the rotation axis OO′, and the value of e is larger than or equal to zero, and smaller than a distance from the rotation axis OO′ to the discharge outlet of the straight groove; when the value of the eccentric distance e is zero, the straight groove is arranged in a radial arrangement; and the second grinding disc has a central position with a mounting portion of the workpiece advancing apparatus provided thereon; under a condition of a grinding pressure and grinding lubrication, a friction coefficient between materials of the first grinding disc&#39;s working face and materials of the processing workpiece is f1, a friction coefficient between materials of the second grinding disc&#39;s working face and materials of the processing workpiece is f2, and f1&gt;f2, so as to ensure the processing workpiece to achieve spinning in the grinding process. The workpiece advancing apparatus of the cylindrical-component grinding device proposed in the present invention, includes a main body, a plurality of material-pushing mechanisms and a plurality of material storage hoppers are arranged on the main body, and the number of the material-pushing mechanism and the number of the material storage hopper are the same with that of the straight grooves in the grinding disc apparatus, each of the material-pushing mechanisms respectively cooperating with one material storage hopper; the material storage hopper has a bottom provided with a push rod inlet and a discharge port; the material-pushing mechanism comprises a through hole provided at the main body&#39;s bottom, the through hole is coaxial with a line connecting a center of the push rod inlet and a center of the discharge port; a push rod and a stopper structure of the push rod are formed inside the through hole; there is a one-to-one correspondence between the discharge port of the material storage hopper and the propulsion port of the straight groove, and all of the push rods are driven one and the same intermittent reciprocating mechanism to pass the processing workpiece in the material storage hopper into the straight groove. 
     The grinding method using the cylindrical-component grinding device of the present invention includes following steps. 
     Step 1 is workpiece feeding. Herein, the workpiece conveying apparatus feeds the processing workpiece into the material storage hopper of the workpiece advancing apparatus, and under the drive of the intermittent reciprocating mechanism, the push rod pushes the processing workpiece in the material storage hopper from the bottom of the material storage hopper to the straight groove, until all the straight grooves are fulfilled with the processing workpiece. 
     Step 2 is grinding processing, in which, the loading apparatus provides loading for the grinding disc apparatus, the workpiece contacts with the first grinding disc&#39;s working face and the second grinding disc&#39;s working face; the power system drives the grinding disc apparatus, the second grinding disc rotates relative to the first grinding disc, with a joint cooperation of the first grinding disc and the second grinding disc, the processing workpiece spins along its axis, and at the same time, the processing workpiece performs translational slide motion from the propulsion port of the straight groove towards the discharge outlet; during the motion, under the effect of free grinding particles in a grinding fluid, a micro material removal of the processing workpiece is achieved, until the processing workpiece has been discharged from the discharge outlet of the straight groove. 
     Step 3 is workpiece cleaning, in which the workpiece and grinding fluid separating apparatus separates the workpiece grinded in step 2 from the grinding fluid, and after filtration and precipitation, the grinding fluid is then in reuse; and after the workpiece is cleaned by the workpiece cleaning apparatus, the method goes on to step 4. 
     Step 4 is that after the workpieces have been disordered by the workpiece mixing apparatus, the method goes back to step 1. 
     After a period of continuous cycle grinding processing, a sampling inspection of the workpiece is made, and if the process requirements are met, the grinding processing ends, or otherwise, the grinding processing continues. 
     Compared with the prior art, the invention has the advantages as follows. 
     As plenty of processing workpieces distributed in the plurality of straight grooves at the same time are simultaneously engaged in the grinding process, and due to the mixing process, the combination of the processing workpieces at the same time is highly random, the work load endured by the cylindrical roller with a larger diameter is greater than that of the cylindrical roller with a smaller diameter, and the work load endured by a processing face of the workpiece at a high position is larger than that of the processing face of the workpiece at a low position, thus facilitating a large material removal on cylindrical surfaces of the cylindrical roller with a larger diameter, a small material removal on cylindrical surfaces of the cylindrical roller with a smaller diameter, as well as a large material removal at a high processing face, and a small material removal on a low processing face, further to improve the consistency of cylindrical surfaces of the cylindrical roller. Because the large number of workpieces involved in processing at the same time and feature that a large material removal is involved on cylindrical surfaces of the cylindrical roller with a larger diameter, and a large material removal at a high position, all contribute to the improvement of processing efficiency on cylindrical surface of the cylindrical roller, thus an ability of a mass production is achieved, an excellent dimensional consistency of the workpiece, and a high shape accuracy and a high processing efficiency of cylindrical surface of the cylindrical roller, are involved, as well as a low processing cost. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an excircle surface super-finishing device for a double-disc straight groove cylindrical component; 
         FIG. 2  is a schematic view of a grinding disc apparatus; 
         FIG. 3  is a schematic view of second grinding disc having a straight groove; 
         FIG. 4  is a cross section view of a workpiece to be processed in the grinding disc apparatus, wherein: (a) illustrates a V-shaped cross-section outline of a working face of the straight groove of the second grinding disc; (b) illustrates an arc-shaped cross-section outline of the working face of the straight groove of the second grinding disc; and (c) illustrates a cross-section outline of a working face the second grinding disc in a V shape with an arc; 
         FIG. 5-1  schematically illustrates a cross section view of a feeding apparatus driven by a disc cam; 
         FIG. 5-2  shows a view of the disc cams in  FIG. 5-1  with different lift limit, wherein: (a) illustrates is a disc cam with a single lift limit, (b) shows a disc cam with double lift limits, and (c) is a view of a disc cam with triple lift limits; 
         FIG. 6  is a schematic longitudinal section view of an advancing apparatus driven by a disc cam; 
         FIG. 7  is a schematic diagram of an advancing apparatus driven by a conical cam; 
     
    
    
     In the figures: 
     reference sign  1  indicates a grinding disc apparatus; reference sign  2  indicates a workpiece advancing mechanism; 
     reference sign  3  indicates a workpiece conveying apparatus; reference sign  4  indicates a workpiece mixing apparatus; 
     reference sign  5  indicates a workpiece and grinding fluid separation apparatus; reference sign  6  indicates a workpiece cleaning apparatus; 
     reference sign  7  indicates a loading apparatus; reference sign  8  indicates a power system; 
     reference sign  9  indicates a processing workpiece; reference sign  11  indicates a first grinding disc; 
     reference sign  111  indicates the first grinding disc&#39;s working face; reference sign  12  indicates a second grinding disc; 
     reference sign OO′ indicates a rotation axis of the second grinding disc relative to the first grinding disc; reference sign  121  indicates a straight groove on the second grinding disc; 
     reference sign  1211  indicates the second grinding disc&#39;s working face; reference sign  1212  indicates a chip-hold groove at the bottom of the straight groove of the second grinding disc; 
     reference sign  211  indicates a disc cam; reference sign  212  indicates a conical cam; 
     reference sign  22  indicates a material-pushing mechanism; reference sign  222  indicates a positioning shaft shoulder; 
     reference sign  223  indicates a spring; reference sign  224  indicates a push rod; 
     reference sign  225  indicates a through hole; reference sign  23  indicates a material storage hopper. 
     Reference sign/indicates the axis of the processing workpiece in the straight groove; 
     Reference sign Δω indicates the relative rotational speed of the second grinding disc and the first grinding disc; 
     reference sign ω 1   indicates the spin angular velocity of processing workpiece under the processing; 
     reference sign α indicates a plane passing through the axis/and perpendicular to the working face of the first grinding disc; 
     reference sign β indicates a normal plane at an unique contacting point or a midpoint A of a contacting arc between the processing workpiece and the straight groove; 
     reference sign θ indicates an angle between plane α and plane β; 
     reference sign e indicates an eccentric distance from the plane α to the second grinding disc&#39;s rotational axis OO′ relative to the first grinding disc; 
     reference sign r indicates an excircle radius of the processing workpiece. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The technical solution of the present invention will now be described in further detail with reference to the accompanying drawings and specific examples. 
     As shown in  FIG. 1 , a cylindrical-component grinding device proposed in the present invention includes a loading apparatus  7 , a power system  8 , and a workpiece advancing apparatus  2 , a grinding disc apparatus  1 , a workpiece and grinding fluid separating apparatus  5 , a workpiece cleaning apparatus  6  and workpiece mixing apparatus  4 , the later five apparatuses connecting with a workpiece conveying apparatus  3  in sequence. The loading apparatus  7  is configured for material loading of the grinding disc apparatus  1  and the power system  8  is configured for driving the grinding disc apparatus  1 . 
     As shown in  FIG. 2 , the grinding disc apparatus  1  includes a first grinding disc  11  and a second grinding disc  12 , and the second grinding disc  12  and the first grinding disc  11  rotate relative to each other. The second grinding disc  12  has a rotation axis OO′ relative to the first grinding disc  11 , a surface of the first grinding disc  11 , opposite to the second grinding disc  12 , is planar, which is a working surface  111  of the first grinding disc  11 . As shown in  FIG. 3 , a set of radial straight grooves  121  are provided on a surface of the second grinding disc  12  opposite to the first grinding disc  11 , and a groove surface of the straight groove  121  is a working surface  1211  of the second grinding disc  12 . As shown in  FIG. 4 , the working face  1211  of the second grinding disc  12  has a cross-section outline in an arcuate shape or a V shape or a V shape with an arc. Herein, the cross-section outline of the working face  1211  of the second grinding disc  12  shown in  FIG. 4 -( a ) is V-shaped, the cross-section outline of the work surface  1211  of the second grinding disc  12  shown in  FIG. 4 -( b ) is in an arcuate shape, and the cross-section outline of the working face  1211  of the second grinding disc  12  as shown in  FIG. 4 -( c ) is a V shape with an arc. The bottom of the straight groove is provided with a chip-hold groove  212 . Processing workpieces  9  are laterally disposed on the eccentric straight groove  121 , to be processed in a grinding working area consisting of the working face  111  of the first grinding disc  11  and the working face  1211  of the second grinding disc  12 . Under load conditions and lubrication conditions of the grinding fluid described in the present invention, the friction pair formed by the material of the working face  111  of the first grinding disc  11  and the material of the processing workpiece  9  has a friction coefficient f1 larger than a friction coefficient f2 of the friction pair formed by the material of the working face  1211  of the second grinding disc  12  and the material of the processing workpiece  9  under the same conditions. 
     During grinding process, the processing workpiece  9  is arranged in the straight groove  121  along a groove extending direction, meanwhile, an outer cylindrical surface of the processing workpiece  9  contacts with the working face  1211  of the second grinding disc  12 , and the working face  1211  of the straight groove  121  locates the position of the excircle surface of the workpiece  9 . The straight, groove  121  has a reference plane α, a plane that passes through an axis/of the processing workpiece arranged in the straight groove, and is perpendicular to the working face  111  of the first grinding disc  11 . There is an angle θ between a normal plane β at a contacting point or a midpoint A of a contacting arc between the processing workpiece  9  and the straight groove  121 , and the reference plane of the straight groove  121 . The angle θ ranges in 30˜60°. One end, of the straight groove  121  close to the center of the second grinding disc  12  is a propulsion port of the processing workpiece, and the other end of the straight groove  121  is a discharge outlet. An eccentric distance e exists between the reference plane a of the straight groove  121  and the second grinding disc&#39;s rotation axis OO′ relative to the first grinding disc. The value of e is larger than or equal to zero, and smaller than a distance from the rotation axis OO′ to the discharge outlet of the straight groove  121 . When the value of the eccentric distance e is zero, the straight groove  121  is actually arranged in a radial arrangement, and the second grinding disc  12  has a mounting portion of the workpiece advancing apparatus  2 , provided at a central position thereof. 
     Under the conditions of the grinding pressure and grinding lubrication, the friction coefficient between the material of the first grinding disc&#39;s working face  111  and the material of the processing workpiece is f1, and the friction coefficient between the material of the second grinding disc&#39;s working face  1211  and the material of the processing workpiece is f2, and f1&gt;f2, so as to ensure that the processing workpiece may achieve spinning in the grinding process. 
     The workpiece advancing apparatus  2  according to the present invention has a structure as shown in  FIGS. 5-1, 5-2, 6 and 7 , including a main body, wherein a plurality of material-pushing mechanisms  22  and a plurality of material storage hoppers  23  are arranged on the main body, the plurality of material-pushing mechanisms  22  are arranged along circumferential distribution, and both the number of the plurality of material-pushing mechanisms  22  and the plurality of the number of the material storage hopper  23  are the same with the number of the straight grooves  121  in the grinding disc apparatus. The material storage hopper  23  has a section dimension matching the dimension of the processing workpiece  9 , and the processing requirements of the processing workpiece  9  with different diameters can be met by replacing the material storage hopper  23  with different cross-section dimensions. Each of the material-pushing mechanisms  22  respectively cooperates with one material storage hopper  23 , the bottom of the material storage hopper  23  is provided with a push rod inlet  231  and a discharge port  232 , the material-pushing mechanism  22  including a through hole  225  provided at the bottom of the main body. The through hole  225  is coaxial with a line connecting the center of the push rod inlet  231  and the center of the discharge port  232 , the through hole  225  communicates with the push rod inlet  231 , and a push rod  224  and a stopper structure of the push rod  224  are provided inside the through hole  225 , The stopper structure consists of a positioning shaft shoulder  222  provided on the push rod  224 , a positioning step provided in the through hole, and a spring  223  disposed on the push rod  224 , the positioning shaft  222  confining the stroke of the push rod  224 , the spring  223  keeping the push rod  224  contacting with the cam. There is a one-to-one correspondence between the discharge port of the material storage hopper  23  and the propulsion port of the straight groove  121 , and all of the push rods  224  always contact with the same intermittent reciprocating mechanism (for example, the disc cam  211  shown in  FIG. 5-1  or the conical cam  212  as shown in  FIG. 7 ). That is to say, driven by the same intermittent reciprocating mechanism, the cam pushes all of the push rods  224  to reciprocate in the through hole  225 , so as to pass the processing workpiece  9  in the material storage hopper  23  into the straight groove  121  through the discharge port  232  at the bottom of the material storage hopper  23 . The processing workpieces  9  are stacked one by one in the material storage hopper  23  and the one workpiece  9  at the bottom has an axis aligned with the axis/of the processing workpiece  9  in the straight groove  121  corresponding to the material storage hopper  23 . When grinding is continued, the workpiece conveying apparatus  3  conveys the processing workpiece  9  to the workpiece advancing mechanism  2 , and the workpiece  9  is then stored in the material storage hopper  23 . 
     The workpiece conveying apparatus  3  according to the present invention employs a common vibration feeding mechanism and a screw feeding mechanism on the market, which function to realize a continuous feeding of the processing workpiece  9 , The workpiece mixing apparatus  4  according to the present invention adopts a common cylindrical workpiece mixing mechanism on the market, for achieving disordering the sequence of the workpiece and improving the randomness of the processing. The workpiece and grinding fluid separating apparatus  5  of the present invention is provided with a precipitation tank, a grinding fluid delivery pipe and a grinding fluid separation apparatus, for conveying the grinding fluid to the device, collecting the used grinding fluid, and for separating the grinding debris and grinding fluid after precipitation and filtration, thus to achieve a recycling of grinding fluid. The workpiece cleaning apparatus  6  of the present invention employs a common workpiece cleaning apparatus on the market, for cleaning the primarily grinded workpiece with a cleaning liquid and for recovering the cleaning liquid. In order to prevent environment pollution, the wastewater produced by cleaning of rollers firstly flows into the precipitation tank to precipitate through the pipe, and precipitated wastewater enters the grinding fluid separation apparatus for a centrifugal separation and filtration. Separated cleaning liquid then returns to the roller cleaning apparatus and gets a reuse. 
     The intermittent reciprocating mechanism in the device of the present invention is driven by a disc cam mechanism or a conical cam mechanism, and in order to complete a function of intermittent reciprocating, the workpiece advancing mechanism  2  can adopt a structure in a variety of solutions: a first embodiment is shown in  FIGS. 5-1, 5-2 and 6 , wherein, (a), (b) and (c) in  FIG. 5-2  show a structure of a disc cam with a single, a double and a triple lift limits, respectively, and a multi-lift-limit disc cam  211  can be used to achieve an intermittent reciprocation, with an operation process that a multi-lift-limit disc cam  211  is used to connect to the first grinding disc  11 , the push rod  224  connects to the second grinding disc  12 , and by virtue of a rotation speed difference between the two grinding discs, the push rod  224  is driven to advance the processing workpiece  9  into the straight groove  121  via the change in the lift distance of the disc cam  211 . 
     Embodiment 2 is shown in  FIG. 7 , in this case, the intermittent reciprocating mechanism is driven by the conical cam  212 , with an operation process that the conical cam  212  reciprocates linearly under the drive of an external power source, so as to further drive the push rod  224  to advance the processing workpiece  9  into the straight groove  121 . Both the embodiment 1 and the embodiment 2 can be adapted to meet the needs of the processing workpiece in different dimensions by changing the cross-section dimension of the cam and by changing the cross-section dimension of the material storage hopper  23 , thus involving a strong applicability. 
     To realize grinding on cylindrical components by virtue of the cylindrical-component grinding device of the present invention, following steps are included. 
     Step 1 is workpiece feeding. Herein, the workpiece conveying apparatus  3  feeds the processing workpiece into the material storage hopper  23  of the workpiece advancing apparatus  2 , and under the drive of the intermittent reciprocating mechanism, the push rod  224  pushes the processing workpiece  9  in the material storage hopper  23  from the bottom of the material storage hopper to the straight groove  121 , until all the straight grooves are fulfilled with the processing workpiece  9 . 
     Step 2 is grinding processing. Herein, the loading apparatus  7  provides loading for the grinding disc apparatus  1 , the workpiece  9  contacts with the first grinding disc&#39;s working face  111  and the second grinding disc&#39;s working face  1211 ; the power system  8  drives the grinding disc apparatus  1 , the second grinding disc  12  rotates relative to the first grinding disc  11 , the processing workpiece  9  is processed in the grinding working area formed by the working face  111  of the first grinding disc  11  and the working face  1211  of the second grinding disc  12 . Under the conditions of the grinding pressure and grinding lubrication, the friction coefficient f1 between the material of the first grinding disc&#39;s working face  111  and the material of the processing workpiece is larger than the friction coefficient f2 between the material of the second grinding disc&#39;s working face  1211  and the material of the processing workpiece, so with the joint cooperation of the first grinding disc  11  and the second grinding disc  12 , the processing workpiece may spinning along its axis, and at the same time, the advancing apparatus  2  keeps pushing the processing workpiece  9  into the straight groove  121 . Pushed by following processing workpieces  9 , the processing workpiece  9  in the straight groove  121  performs translational slide motion from the propulsion port of the straight groove  121  towards the discharge outlet. During the above-described motion, the contacting region between the working face of the grinding disk apparatus  1  and an outer cylindrical surface of the processing workpiece  9 , under the effect of free grinding particles in the grinding fluid, may realize a micro material removal of the processing workpiece  9 , until the processing workpiece  9  has been discharged from the discharge outlet of the straight groove  121 . 
     During the grinding process, plenty of processing workpieces  9  distributed in the plurality of straight grooves  121  at the same time are simultaneously engaged in the grinding process, and the combination of the processing workpieces  9  at the same time is highly random, the load endured by the processing workpiece  9  with a larger diameter is greater than that of the processing workpiece  9  with a smaller diameter, thus facilitating a large material removal on excircle surfaces of the processing workpiece  9  in a larger diameter, as well as a small material removal on excircle surfaces of the processing workpiece  9  in a smaller diameter, further to improve the processing efficiency, and dimensional accuracy and consistency of excircle surfaces of the processing workpiece  9 . 
     Step 3 is workpiece cleaning. Herein, the workpiece and grinding fluid separating apparatus  5  separates the workpiece grinded in step 2 from the grinding fluid, and after filtration and precipitation, the grinding fluid is then in reuse. After the workpiece is cleaned by the workpiece cleaning apparatus  6 , the process goes on to step 4. 
     Step 4 is that after the workpieces have been disordered by the workpiece mixing apparatus  4 , the process goes back to step 1; 
     After a period of continuous cycle grinding processing, a sampling inspection of the workpiece is made, and if the result meets the process requirements, the grinding processing ends, or otherwise, the grinding processing continues. 
     With the grinding method of the present invention, plenty of the processing workpieces  9  distributed in the straight groove  121  at the same time are engaged in the grinding process and the combination of the processing workpieces  9  at the same time is highly random, the load endured by the processing workpiece  9  with a larger diameter is greater than that of the processing workpiece  9  with a smaller diameter, thus facilitating a large material removal on excircle surfaces of the processing workpiece  9  in a larger diameter, as well as a small material removal on excircle surfaces of the processing workpiece  9  in a smaller diameter, further to improve the dimensional consistency of cylindrical surfaces of the processing workpiece  9 . A large removal of the material at a high position and a larger material removal of the processing workpiece  9  in a larger diameter, contribute to the improvement of processing efficiency on cylindrical surface of the processing workpiece  9 . 
     Though the invention has been described above with reference to the accompanying drawings, the invention shall not be limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative and not restrictive, and for one of ordinary skill in the art, under the inspiration of the present invention, many modifications may be made without departing from the spirit of the invention, which shall fall into the protection scope of the present invention.