NTN CORPORATION : Patent Issued for Work Feeder for Roller End Face Working Machine, Roller End Face Working Machine and Rollers for Roller Bearing
Resource from: 4-traders.com Likes:247
Jan 10,2014
According to news reporting originating from Alexandria, Virginia, by VerticalNews journalists, a patent by the inventor Sugitatsu, Satoshi (Iwata, JP), filed on March 29, 2010, was published online on December 24, 2013.
The assignee for this patent, patent number 8613643, is NTN Corporation (Osaka, JP).
Reporters obtained the following quote from the background information supplied by the inventors: "As a method of performing crowning processing on end faces of a roller, there is known processing using a double-head surface grinder and processing using a cup grinding stone. As a method of feeding a workpiece, it is general to feed a workpiece using a carrier (rotary carrier) having pockets arranged concentrically in an outer rim portion of a disk thereof.
"However, the size of the carrier pocket is larger than the diameter of the workpiece, and hence a 'clearance' is formed between the two (between the workpiece and the pocket), with the result that the processing position and the posture are unstable. Further, the carrier itself does not have any action of controlling the rotation of the workpiece, and the rotation depends entirely on processability of the grinding stone, with the result that stable rotation cannot be attained. Hence, uniform processing cannot be performed in a circumferential direction and runout accuracy of end faces cannot be obtained.
"Therefore, in recent years, there have been developed products that enable both the end faces of the workpiece to be ground with high accuracy (Patent Literature 1 and Patent Literature 2).
"Patent Literature 1 describes a double-head surface grinder. As illustrated in FIG. 11, the double-head surface grinder includes a pair of ring-like grinding stones 1, a carrier 4 arranged between the grinding stones 1, and a ring-like guide member 5 arranged on an outer periphery side of the carrier 4.
"The carrier 4 has pockets 3 formed in its radially-outer surface and arranged at a predetermined pitch along the circumferential direction. Workpieces W are fitted to the pockets 3. Further, the workpieces W can be held in the pockets 3 by the guide member 5.
"In this case, the guide member 5 is arranged by decentering an axis O1 of the guide member 5 from a carrier axis O by a decentering amount A so that a gap between a guide surface (radially-inner surface of the guide member 5) and the carrier 4 is smaller on a processing position H side and larger on a loading position X side opposite to the processing position H. In this case, the guide member 5 holds, together with the pocket 3, the workpiece W fed to the pocket 3 of the carrier 4 at the loading position X, and guides the workpiece W from the loading position x to an unloading position Y through the processing position H while rotating the workpiece W about its axis along with the rotation of the carrier 4.
"The gap between the guide surface and the carrier 4 is larger on the loading position X side, and hence the workpiece W can be fed to the pocket 3 easily and quickly. Further, the gap between the guide surface and the carrier 4 is smaller on the processing position H side, and hence the stability of the posture of the workpiece W is enhanced, with the result that both the end faces of the workpiece W can be ground with high accuracy.
"As illustrated in FIG. 12, the product described in Patent Literature 2 includes a rotatable inner disk 6, a cage 9 holding a plurality workpieces substantially equiangularly on a radially-outer portion having pocket portions 8 and a drive belt 10 stretched over radially-outer portions of the plurality of workpieces W held by the inner disk 6 and the cage 9.
"Further, by rotationally driving the inner disk 6 and the drive belt 10 in opposite directions, rotational motion is applied to the workpieces W, and further, by rotating the cage 9, revolutional motion is applied to the workpieces W.
"Further, cup grinding stones for processing the end faces of the workpiece W are pressed at two positions against the end faces of the workpiece W at a fixed pressure from opposite directions, and hence both the end faces of the workpiece W can be processed.
"Accordingly, in the processing apparatus illustrated in FIG. 12, the end faces of the workpiece can be processed by using the elastic processing tool while rotating and revolving the workpiece. Thus, the rotation of the workpiece is kept stable, and the runout accuracy of the roller end faces can be enhanced.
"By the way, there is conventionally a tangential feed grinding method using a centerless grinder (Patent Literature 3). In this case, as illustrated in FIG. 13, the centerless grinder includes a grinding wheel 11, a regulating wheel 12, and a carrier 13. Further, the centerless grinder includes a rotation shaft 12a and a rotation shaft 13a for supporting and driving the grinding wheel 11 and the carrier 13, respectively. Further, at least one end face 15 of a workpiece W fitted into a workpiece pocket 14 of the carrier 13 is in a state of being closed completely or partially."
In addition to obtaining background information on this patent, VerticalNews editors also obtained the inventor's summary information for this patent: "Technical Problems
"In the product described in Patent Literature 1 above, the posture of the workpiece W is restrained by the carrier 4 and the guide member 5, and the rotation is applied to the workpiece W by the guide member 5. However, the posture of the workpiece W is stabilized only within the narrow range of the processing position. Therefore, there is a fear that the posture of the workpiece W is not stable when the workpiece W enters the processing position because the posture is unstable during transport of the workpiece W to the processing position, and an unnecessary external force is applied to the workpiece W, the carrier 4, and the guide member 5. Accordingly, the workpiece W is not sufficiently pressed against the guide member 5, and the rotation of the workpiece is also unstable, with the result that the grinding cannot be performed with high accuracy.
"Further, in the product described in Patent Literature 2, the rotation is applied to the workpiece W by the drive belt 10, but the workpiece itself constitutes part of the drive system, and hence, when there is a pocket having no workpiece W fed thereto due to a feeding failure or the like, the belt 10 loses the tensile force. As a result, the drive force cannot be obtained. Further, the carrier (cage 9) and the belt 10 come into direct contact with each other, which causes trouble such as damage to the belt.
"In the case of performing the tangential feed grinding as illustrated in FIG. 13, at least one end face 15 of the workpiece W is in the state of being closed completely or partially. Therefore, both the end faces cannot be ground at the same time, which leads to lower productivity.
"In view of the above-mentioned problems, the present invention has an object to provide a workpiece feeder for roller end face processing which is capable of feeding a roller to a roller end face processing machine in a stable posture, to provide a roller end face processing machine which is capable of stably and highly accurately processing both end faces of the roller fed by such a workpiece feeder for roller end face processing, and to provide a roller for a rolling bearing processed by such a roller end face processing machine.
"Solution to Problems
"A workpiece feeder for roller end face processing according to the present invention includes: a carrier ring having a plurality of recesses arranged in a radially-inner surface thereof at a predetermined pitch along a circumferential direction; a regulating wheel fitted into the carrier ring to form roller fitting cavities between a radially-outer surface of the regulating wheel and the plurality of recesses; a carrier support for supporting the carrier ring on a radially-outer side with respect to the plurality of recesses; and rotational force applying means for applying rotation to the carrier ring on the radially-outer side with respect to the plurality of recesses, in which, into each of the roller fitting cavities, a roller is fitted so that end faces of the roller are exposed to an outside with an axial direction of the roller being in parallel to an axial direction of the carrier ring, and in which the plurality of recesses each include an elastic member arranged therein, the elastic member being elastically brought into contact with a radially-outer surface of the roller to restrain a posture of the roller.
"According to the workpiece feeder for roller end face processing of the present invention, the elastic member for restraining the posture of the roller is arranged in each of the recesses of the carrier ring, and hence the workpiece (roller) during transport can be kept in a stable posture. At this time, the carrier support and the rotational force applying means are arranged on the radially-outer side with respect to the recesses, and thus the carrier support and the rotational force applying means do not affect the exposure of the end faces of the roller to the outside.
"It is preferred that the workpiece feeder for roller end face processing further include: a roller loading position, at which the roller is fittable into the each of the roller fitting cavities along the axial direction of the roller in parallel to the axial direction of the carrier ring; and an end face processing position, at which both the end faces of the roller fitted into the each of the roller fitting cavities are processed, in which, at the roller loading position, a radial gap dimension of the each of the roller fitting cavities is set larger than an outer diameter of the roller, and in which, at the end face processing position, the radial gap dimension of the each of the roller fitting cavities is set substantially equal to the outer diameter of the roller.
"With this structure, the roller can be fitted at the loading position along the axial direction of the roller in parallel to the axial direction of the carrier ring. In addition, at the roller loading position, the radial gap dimension of the roller fitting cavity is larger than the outer diameter of the roller, and hence the fitting property (loading property) of the roller into the fitting cavity can be enhanced. Further, at the end face processing position, the radial gap dimension of the roller fitting cavity is set substantially equal to the outer diameter of the roller, and hence, at the end face processing position, the radial 'clearance' in the fitting cavity is eliminated.
"It is preferred that the roller loading position and the end face processing position be situated opposite to each other by 180 degrees across an axis of the carrier ring, and the workpiece feeder for roller end face processing further include a roller unloading position, at which the roller is unloadable along the axial direction of the roller in parallel to the axial direction of the carrier ring, the roller unloading position being situated at a position spaced apart from the end face processing position by 90 degrees along a rotation direction of the carrier ring.
"The rotational force applying means may apply the rotational force by driving a belt or a roller.
"A first roller end face processing machine according to the present invention includes: the workpiece feeder for roller end face processing described above; and a double-head grinder including a pair of grinding stones for grinding the end faces of the roller.
"A second roller end face processing machine according to the present invention includes: the workpiece feeder for roller end face processing described above; and a cup grinding stone for grinding the end faces of the roller.
"A roller for a rolling bearing according to the present invention is obtained by processing both end faces thereof in the roller end face processing machine described above.
"Advantageous Effects of Invention
"According to the present invention, the end faces of the roller are exposed to the outside with the axial direction of the workpiece (roller) being in parallel to the axial direction of the carrier ring. Accordingly, it is possible to obtain a sufficient region in which the end faces of the roller interfere with the surfaces of the grinding stones, and to process both the end faces of the roller uniformly at the same time with high accuracy, with the result that the grinding processing is stabilized. Further, the workpiece (roller) during transport can be kept in a stable posture. Accordingly, it is possible to process the end faces of the workpiece (roller) in the state of the stable posture, and thus the processing can be performed with high accuracy.
"At the loading position, the radial gap dimension of the roller fitting cavity is set larger than the outer diameter of the roller, and hence the fitting property of the roller into the fitting cavity can be enhanced, with the result that working efficiency can be enhanced. Further, at the end face processing position, the radial gap dimension of the roller fitting cavity is set substantially equal to the outer diameter of the roller, and hence the 'clearance' of the roller at the end face processing position is eliminated. Thus, there is no backlash at the time of processing the end faces, and the stable posture can be maintained, with the result that the processing can be performed with high accuracy.
"The roller loading position and the end face processing position are situated opposite to each other by 180 degrees across the axis of the carrier ring, and hence the loading property of the roller at the roller loading position and the processability at the end face processing position can be enhanced. Further, the unloading position is provided at the position spaced apart from the end face processing position by 90 degrees along the rotation direction of the carrier ring, and hence the unloading property of the roller at the unloading position after the processing can be enhanced.
"The rotational force applying means may apply the rotational force by driving a belt or a roller, and hence various existing apparatuses may be used therefor.
"The roller end face processing machine may include the double-head grinder or the cup grinding stone, and the grinding can be performed with high accuracy irrespective of which of the two is used. In addition, an existing double-head grinder or cup grinding stone may be used, with the result that cost reduction can be achieved.
"The roller for a rolling bearing processed as described above is a high-quality roller, and hence the rolling bearing using such a roller exerts a function as a bearing with high accuracy."
(4-traders.com)
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1.The news above mentioned with detailed source are from internet.We are trying our best to assure they are accurate ,timely and safe so as to let bearing users and sellers read more related info.However, it doesn't mean we agree with any point of view referred in above contents and we are not responsible for the authenticity. If you want to publish the news,please note the source and you will be legally responsible for the news published.
2.All news edited and translated by us are specially noted the source"CBCC".
3.For investors,please be cautious for all news.We don't bear any damage brought by late and inaccurate news.
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