JP2016161090A - Linear bushing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear bushing in which end rings are fitted to both ends of a cage of substantial square-shaped section having an outer cylinder fitted and inserted to it, circulating passages where rolling members run under acceptance of load are oppositely arranged to face for every adjoining passages and a slider is reciprocated and slid in a stable and smooth manner on a shaft.SOLUTION: End rings 6 cover both ends 30 of a cage 5 protruded out of an outer cylinder 3, are fitted to them and abutted against end surfaces 31 of the outer cylinder 3. A circulating recess groove 25 of the cage 5 is constituted by a raceway recess groove 27 provided with a slit 26 in an axial direction opposing against a raceway surface 16 of a shaft 1, a U-turn recess groove 28 extending in parallel with the recess groove, and a pair of direction changing-over recess grooves 29 communicating with them. Each of adjoining circulation passages 44 is arranged at each of linear symmetrical positions where return passages 43 are alternatively faced against raceway passages 41 while holding a corner part 15 of the cage 5.SELECTED DRAWING: Figure 5

Description

  The present invention comprises a long shaft and a slider that moves relative to each other via a rolling element into which the shaft is fitted, and the slider holds the outer cylinder and the rolling element disposed in the outer cylinder. It is related with the linear bushing which consists of.

  Conventionally, a linear bushing is composed of a slider into which a long shaft is inserted, and a retainer for holding a rolling element disposed in an outer cylinder constituting the slider is composed of a synthetic resin or the like. The retainer is fixed to the outer cylinder by fitting retaining rings in grooves formed at both ends of the outer cylinder so as not to fall off from the cylinder.

  As a conventionally known polygonal column type ball bushing device, a combination of a ball bushing and a housing is known. The polygonal ball bushing device is a combination of a flat surface and a circular arc surface, and is configured by combining the top of the cylindrical surface so as to be inscribed in the cylindrical inner peripheral surface of the housing, and folding the bent edge of the outer cylinder. A cage is fixed to the outer cylinder (for example, see Patent Document 1).

  In addition, conventionally known ball bushings include an outer sleeve having a track extending in the axial direction on the inner cylinder, an axial guide track distributed around the outer sleeve, and two guide tracks. It comprises a cage having several ball guides composed of a semicircular turning track connected to and an endless sphere array arranged on the ball guide. The ball bush has an outer sleeve provided with a trajectory extending in the axial direction for the ball and a return trajectory on the inner cylinder, and the length of the outer sleeve is substantially equal to the guide raceway portion of the shaft cage in the cage, and the cage is made of plastic. A portion having a semicircular turning track protrudes from the outer sleeve, and a plastic end ring is placed on the protruding portion of the cage to cover the turning track (for example, see Patent Document 2).

JP 50-70759 A Japanese Patent Publication No.59-11771

  However, the above-described polygonal column type ball bushing device has a problem that it is troublesome to assemble. Since conventional linear bushings are structured to use retaining rings to fix the cage to the outer cylinder, it is necessary to form grooves at both ends of the inner periphery of the outer cylinder and fit the retaining rings into the grooves. There was a problem that the number of parts was large and the structure was complicated. The conventional ball bushing has a plastic end ring that covers the cage protruding from both ends of the outer sleeve, and the protruding part of the inner periphery of the end ring is caulked and fixed to the edge of the cage. If it is troublesome and the notch portions are provided at both ends of the body surface of the cage, the insertion direction of the end ring into the cage is limited.

  Therefore, the present applicant has developed a linear bushing in which the outer cylinder and the cage are configured as one piece to reduce the number of parts, and the cage is properly positioned and engaged with the outer cylinder and firmly fixed to each other. Filed as Japanese Patent Application No. 2013-176422. In the linear bushing, at least a pair of protrusions protruding from both ends of the outer peripheral surface is formed on the cage, and an elongated window portion extending in the longitudinal direction in which the pair of protrusions are fitted is formed on the outer cylinder. The pair of protrusions are fitted into the window portion at the end of the outer cylinder, so that the cage is positioned and fixed with respect to the outer cylinder in the longitudinal direction and the rotation direction. Since the linear bushing has a structure in which a window is formed in the outer cylinder and the circulation path is opened and exposed, there is a problem that foreign matter such as dust may enter from the outside.

  In order to solve the above-mentioned problem, the present applicant fits end rings to both ends of a polygonal cage into which a polygonal outer cylinder is inserted, and positions and fixes them appropriately in the rotational direction and the axial direction. A linear bushing was developed and a patent application was filed as Japanese Patent Application No. 2014-158933. In the linear bushing, the end ring is fitted to the end of the cage protruding from the outer cylinder and is brought into contact with the end surface of the outer cylinder to cover the outer periphery of both ends of the cage. The circulation groove of the cage is composed of a track groove having a slit on the track surface facing the track surface, a return groove extending in parallel therewith, and a pair of direction changing grooves communicating with them. An outer circumferential groove is formed on the outer circumferential surface of the cage, and the projections of the inner circumferential groove of the end ring are engaged with the projections formed at the ends of both grooves and positioned in the rotational direction. A cylinder is interposed and positioned and fixed in the longitudinal direction of the cage. However, the linear bushing may not allow the slider to slide smoothly. That is, normally, in the linear bushing, the cage is incorporated with a slight gap with respect to the outer cylinder. In the previous linear bushing, the raceway surface of the outer cylinder was flat, so that when the rolling element rolls on the raceway, the rolling element rolls easily and adversely affects the smooth sliding motion of the slider. There is a risk of giving. In other words, the slider in which the cage is incorporated does not slide stably when moved relative to the shaft, and is swung with respect to the shaft. Therefore, there is a problem of how to configure the slider in order to prevent such a phenomenon from occurring.

  An object of the present invention is to solve the above-mentioned problems. The outer cylinder and the end ring are formed in a circular cross section, and the inner peripheral surface of the outer cylinder is formed in a raceway surface having a circular arc shape. The rolling positions of the rolling elements are stabilized, and adjacent circulation paths of a plurality of circulation paths formed on the slider are arranged symmetrically with respect to the axial center of the corner of the cage. By changing the arrangement of the track path, return path, and direction change path around the axis, the rolling element position in the circulation path is stabilized, and the sliding motion of the slider incorporating the cage is not rattled. , A smooth and stable sliding movement of the slider, and a polygonal outer cylinder having an inner peripheral surface, a polygonal cage that holds the rolling elements positioned and fixed to each other in the outer cylinder, and an outer cylinder Proper positioning on both ends of the cage protruding from the end of the A simple structure is constructed from a pair of end rings that are fitted and fixed in place, and the cage is easily and accurately inserted into the outer cylinder. By properly positioning and fixing each other in the axial direction, the outer periphery of the slider can be prevented from entering the outside, and dust can be prevented from entering from the outside. It is to provide a linear bushing consisting of easily configuring proper positioning and assembling of an outer cylinder and an end ring.

According to the present invention, a long shaft having a circular cross section in which a first raceway surface is formed on a first outer peripheral surface, and relative to the shaft along a longitudinal direction of the shaft through a plurality of rolling element balls. The slider has a slidable slider, the second outer peripheral surface having a circular cross section, the first inner peripheral surface having a substantially square cross section, and a second raceway surface on which the rolling element can roll along the longitudinal direction; An outer cylinder formed with a return road surface extending in parallel with the second raceway surface, a retainer having a substantially rectangular cross-section that is fitted into the outer cylinder and protrudes from both end surfaces of the outer cylinder, and the outer cylinder A pair of end rings that are fitted and covered with the second inner peripheral surface having a substantially square cross section over the entire length of the end portion of the cage protruding from the end surface of the retainer. Has
The retainer has a plurality of circuit-shaped circulation grooves in which the rolling element rolls and circulates on a third outer peripheral surface having a substantially quadrangular cross section similar to the outer cylinder, and a fourth outer periphery of the end ring. The surface is formed in a circular cross section smaller than the second outer peripheral surface of the outer cylinder, and the circulation groove of the retainer is the first because the rolling element contacts the first raceway surface of the shaft. 3. A track groove in which an inner peripheral surface is formed with a slit extending along the longitudinal direction, a return groove extending in parallel with the track groove and separated by a partition wall, and the track at the end of the cage It is comprised from a pair of direction change path ditch | groove which connects a ditch | groove and the said return ditch | groove,
The slider includes a track path on which the rolling elements formed by the first raceway surface of the shaft and the second raceway surface of the outer cylinder in a region of the raceway groove of the cage are loaded and rolled. A return path formed by the return groove of the retainer and the return road surface of the outer cylinder; and the direction change path recess of the retainer and the end ring that communicate with the track path and the return path. The direction change path formed by the second inner peripheral surface of the circuit forms four endless circulation paths through which the rolling elements circulate, and the adjacent circulation path has the return path to the track path. In contrast, the present invention relates to a linear bushing, which is alternately arranged in opposite directions and arranged at line-symmetrical positions across the first corner of the cage.

  Further, in this linear bushing, the third outer peripheral surface of the cage is formed with a groove extending in the entire length in the longitudinal direction, and both groove end portions of the groove have stepped portions protruding outward from the groove. A plurality of arc-shaped first arc surfaces extending along the longitudinal direction are formed on the second inner peripheral surface of the end ring, and projecting inwardly at the center of the first arc surface A protrusion is formed, and the slider is positioned in the rotational direction by fitting the retainer into the outer tube, and the end ring is connected to the end of the retainer. The end ring is positioned in the circumferential direction with respect to the retainer and is engaged with the outer cylinder by engaging the protrusions of the end ring with the stepped portions of the retainer. The cage is positioned in the longitudinal direction. It is intended to be fixed.

  The outer cylinder has a second arc surface in which the second raceway surface is formed in an R shape on the first inner circumferential surface, and a second corner portion between the return arc surface and the second arc surface. The third circular arc surface forms a substantially square cross section.

  The retainer is similar to the outer cylinder by a fourth arc surface parallel to the first inner peripheral surface of the outer cylinder and a fifth arc surface of a second corner between the fourth arc surfaces. And the concave groove is formed along the longitudinal direction of the fourth arc surface of the cage.

  In addition, the first arc surface of the end ring is formed at a central position where the first arc surface is fitted to the second corner portion of the cage, and the direction change path of the cage is provided on both sides of the first arc surface. A sixth arc surface on the second inner peripheral surface that covers the concave groove and forms the direction change path is formed. Furthermore, the first arc surface adjacent to the end ring extends in the longitudinal direction as a ridge-like projection that protrudes inwardly at the center of the region corresponding to the fourth arc surface of the cage. Is.

  In addition, the concave groove of the cage has a trapezoidal cross-sectional shape, and the protruding portion of the end ring is formed on the cage end surface side of the step portion formed at the groove end of the concave groove. Is formed in a circumferential direction with respect to the cage, and a tapered guide groove is formed to engage and guide the groove. The protrusion of the end ring is elastically deformed in cooperation with the cage. And over the protrusion along the tapered guide groove of the cage, and fitted into the groove of the cage.

  The projection of the end ring is located at the center of the end ring in the longitudinal direction, and the first arc surface of the end ring is located with respect to the center position of the raceway groove of the cage. It is formed symmetrically. Further, the end ring is configured to be fitted to either side of the end portion of the cage, and the protruding portion extends from the one end portion to the other end portion of the cage. It is guided by the groove and is movable along the longitudinal direction.

  In addition, the linear bushing has an inspection member at a position corresponding to the center position of the track groove to inspect and determine the number of the rolling elements incorporated in the circulation groove at the end of the cage. A through-hole extending in the longitudinal direction for inserting a plug is formed on each end face. Moreover, the said retainer is comprised in the position where the said adjacent circulation ditch | groove mutually opposed each said return ditch | groove.

  Since the linear bushing according to the present invention is configured as described above, it is easy to insert the cage into the outer cylinder having a simple shape, and end rings are sandwiched between both ends of the cage. Positioning and fitting can be performed easily and accurately, the outer cylinder, the cage and the end ring can be easily assembled with high accuracy, and the cost of the linear bushing can be reduced. In particular, the plurality of circulation paths formed on the slider are arranged so that adjacent circulation paths are in a line-symmetrical position with respect to the axial center of the corner of the cage, in other words, the circulation paths provided on the slider The arrangement of the track path, return path and direction change path around the axis is changed to stabilize the position of the rolling element in the circulation path, and as a result, the slider slides with respect to the shaft without rattling. The structure of the cage acts as a function for providing a smooth sliding motion, and the slider can perform a smooth and stable relative reciprocating sliding motion on the shaft. Furthermore, since the second raceway surface formed on the outer cylinder is formed in an R shape with an arcuate surface, the rolling element rolling on the raceway composed of the first raceway surface and the second raceway surface is stable. There is no fear of shaking in the circumferential direction, and it can roll stably and smoothly without wobbling. In addition, the outer circumferential surface of the cage is formed with an outer circumferential groove that can be easily and properly inserted and fixed in the end ring over the entire length in the longitudinal direction. When the end ring is positioned and fixed in the rotation direction and the end ring is inserted into the cage and no outer cylinder is interposed, the end ring can move in the longitudinal direction along the outer circumferential groove. The outer cylinder can be easily positioned and fixed in the axial direction with respect to the cage, and the direction in which the end ring is assembled into the cage is not limited, and the end ring can be mounted from either end of the cage. It is constructed so that it can be assembled, and the inner circumferential surface of the end ring is fitted with an arc surface of an inner circumferential groove that fits closely to the outer circumferential surface of the cage. End Ring of the assembly is properly can be easily performed, increases the degree of freedom at the time of assembly, it is possible mass production of using an automatic assembly machine.

It is a perspective view which shows one Example of the linear bushing by this invention. It is a disassembled perspective view which shows the slider in the linear bushing of FIG. It is the front view which showed the linear bushing of FIG. 1 and was seen from the end surface position of the slider. It is sectional drawing which shows the slider inserted by the axis | shaft in the AA position of the linear bushing of FIG. FIG. 5 is a cross-sectional view showing the slider at the BB position of the linear bushing of FIG. 4. It is sectional drawing which shows the slider in CC position of the linear bushing of FIG. It is sectional drawing which shows the engagement state of the holder | retainer and end ring in the slider in the area | region shown with the code | symbol D of the linear bushing of FIG. It is sectional drawing which shows the insertion state of the holder | retainer and end ring in the slider which shows the area | region shown with the code | symbol E of the linear bushing of FIG. It is a front view which shows the holder | retainer which comprises the linear bushing of FIG. It is a top view which shows the holder | retainer of FIG. FIG. 10 is a cross-sectional view showing the cage at the FF position in FIG. 9. It is sectional drawing which shows the holder | retainer in the HH position of FIG. It is an enlarged front view which shows the holder | retainer in the area | region shown with the code | symbol G of FIG. It is an expanded sectional view which shows the holder | retainer in the area | region shown with the code | symbol I of FIG. It is an expanded sectional view which shows the holder | retainer in the area | region shown with the code | symbol J of FIG. It is a front view which shows the end ring in the linear bushing of FIG. It is sectional drawing which shows the end ring in the KK position of FIG. It is an enlarged front view of the end ring in the area | region shown with the code | symbol L of FIG. It is an enlarged front view of the end ring in the area | region shown with the code | symbol M of FIG. It is a front view which shows the outer cylinder in the linear bushing of FIG. It is sectional drawing which shows the outer cylinder in the NN position of FIG.

  Hereinafter, an embodiment of a linear bushing according to the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 6, the linear bushing according to the present invention generally has an elongated round shape having a circular cross section in which a raceway surface 16 (first raceway surface) is formed on an outer circumference surface 10 (first outer circumference surface). The shaft 1 is composed of a shaft 1 and a slider 2 that can be relatively slid along the longitudinal direction of the shaft 1 through balls 4 that are rolling elements by inserting the shaft 1 (see FIG. 1). . As shown in FIG. 2, the slider 2 mainly includes an outer cylinder 3, a cage 5, an end ring 6, and a ball 4 that is a rolling element. Specifically, the slider 2 includes a raceway surface 17 (second raceway surface) on which the ball 4 rolls on an arc surface 19 (second arc surface) of the inner circumference surface 7 (first inner circumference surface) and a return road surface 24. A circuit shape for forming a circulation path 44 through which a ball 4 as a rolling element circulates by being inserted from an insertion opening 46 in an inner peripheral surface 7 of the outer cylinder 3 and the outer cylinder 3 formed of a thin steel plate formed with A plurality of circulation concave grooves 25 are fitted into the retainer 5 formed on the outer peripheral surface 12 (third outer peripheral surface) and the end 30 of the retainer 5 protruding from both end surfaces 31 of the outer cylinder 3 from the insertion opening 48 respectively. The raceway surface 16 of the outer circumference surface 10 of the shaft 1 and the raceway surface of the outer cylinder 3 through the pair of end rings 6 that respectively cover the outer circumference surface 12 of the end portion 30 and the slit 26 of the window portion formed in the cage 5. 17 and rolls along the circulation groove 25 of the cage 5 while being held by the cage 5. And a ball 4 is a rolling element number. The cage 5 is configured such that the shaft 1 is inserted into the insertion opening 47 and slides on the shaft 1.

  In this linear bushing, the outer cylinder 3 has an outer peripheral surface 11 (second outer peripheral surface) having a circular cross section, and an inner peripheral surface 7 having fitting insertion openings 46 at both ends, which is polygonal (in the embodiment, a substantially rectangular cross section). It is formed into a one-piece shape by pressing. In the cage 5, the inner peripheral surface 8 (third inner peripheral surface) having the outer peripheral surface 12 having a polygonal shape (in the embodiment, a substantially square cross section) and the both end surfaces 34 having insertion insertion openings 47 is inserted into the shaft 1. It is formed into a one-piece shape by resin molding into a circular cross section. Further, the end ring 6 has an outer peripheral surface 13 (fourth outer peripheral surface) having a circular cross-section and an inner peripheral surface 9 (second inner peripheral surface) having fitting insertion openings 48 at both ends. It is formed into a one-piece shape by resin molding processing in a substantially square cross section). The slider 2 includes a metal outer cylinder 3, a synthetic resin cage 5, a pair of synthetic resin end rings 6, and balls 4 of rolling elements. The outer cylinder 3 can be formed into a cylindrical shape by, for example, pressing, the outer peripheral surface 10 is circular, and the inner peripheral surface 7 is formed in a polygonal shape. In the embodiment, the polygonal shape is a substantially square cross section. It is formed into a shape. Further, the outer cylinder 3 has a corner portion between four arcuate surfaces 19 and an arcuate surface 19 forming a raceway surface 17 formed so that the inner peripheral surface 7 extends along the longitudinal direction so that the ball 4 can roll. Four arcuate surfaces 20 (third arcuate surfaces) forming a return road surface 24 formed at 14 (second corner) are substantially formed in a quadrangular shape. Specifically, since the circular arc surface 20 cannot be formed into a predetermined shape only by pressing, the outer cylinder 3 is formed into a cylindrical shape by pressing and then formed by finishing by shaving. The outer cylinder 3 is formed by progressive pressing, and the outer shape of the outer cylinder 3 is formed into a pipe shape with a thin steel plate. After punching one end of the outer cylinder 3, the arc surface 20 of the outer cylinder 3 is shaved. Finishing process is completed by scraping off by processing. In the cage 5, a circulation concave groove 25 in which the ball 4 can circulate and roll is formed on the outer peripheral surface 12. The circulation groove 25 is formed with a track groove 27 in which a slit 26 serving as a window for forming a track 41 on which the ball 4 rolls is formed.

  In this linear bushing, the outer cylinder 3 is formed by press-molding a thin steel plate as shown in FIGS. 20 and 21, and the heat treatment of the outer cylinder 3 is performed by quenching and tempering after carburizing treatment. It is formed by barrel polishing after the heat treatment. The outer cylinder 3 includes a plurality of (four in the embodiment) arcuate surfaces 19 in which the raceway surface 17 is formed on the inner peripheral surface 7 and a corner having a return road surface 24 between the arcuate surfaces 19 smaller than the radius of curvature of the arcuate surface 19. 14 is formed in a polygonal cross section. Here, since the raceway surface 17 of the outer cylinder 3 is formed by pressing, the radius of curvature is larger than that of the circular arc surface 20 formed by shaving. The raceway surface 17 formed on the outer cylinder 3 is formed at positions orthogonal to the slider 2 and formed at four arcuate surfaces 19 so that the ball 4 can slide smoothly. Accordingly, the raceway surface 16 formed on the shaft 1 is formed at positions orthogonal to each other on the outer peripheral surface 10 facing the raceway surface 17.

  Further, as shown in FIGS. 9 to 15, the cage 5 includes an outer peripheral surface 12 having an arc surface 21 (fourth arc surface) and an arc surface 22 (fifth arc surface), and the inner peripheral surface of the outer cylinder 3. 7 is formed in a quadrangular shape similar to 7, formed by an outer peripheral surface 12 in which four rows of circulation concave grooves 25 through which the balls 4 circulate and an inner peripheral surface 8 into which the shaft 1 is inserted, and an outer cylinder 3, the end portions 30 are protruded from both end surfaces 31 of the outer cylinder 3. The cage 5 is formed with tapered guide grooves 40 at four corners 15 (first corners) of the end surface 34, and the grooves 40 are gated when the cage 5 is formed. It serves as a mouth for use. Further, the outer peripheral surface 12 of the cage 5 is composed of, in particular, an arcuate surface 21 in which the track groove 27 is formed and an arcuate surface 22 in which the return groove 28 is formed, as shown in FIGS. The center of the arc surface 22 in the axial direction is formed so as to form the corner 15. The cage 5 has a substantially quadrangular cross-sectional shape similar to that of the outer cylinder 3 with an arc surface 21 parallel to the inner peripheral surface 7 of the outer cylinder 3 and an arc surface 22 of the corner 15 between the arc surfaces 21. A groove 32 is formed along the longitudinal direction of the circular arc surface 21 of the cage 5.

  Further, since the end ring 6 has a substantially square inner peripheral surface 9, the arcuate surface 18 (first arcuate surface) of the corner portion in which the protrusions 38 are formed corresponding to the four corner portions 15 of the cage 5. ) And the arcuate surfaces 23 (sixth arcuate surfaces) on both sides thereof constitute one set, and the four sets constitute the inner peripheral surface 9 of the end ring 6. Further, the outer peripheral surface 13 of the end ring 6 is substantially circular and is formed in a circular cross section that is smaller than the outer peripheral surface 11 of the outer cylinder 3. The slider 2 is positioned in the rotational direction by inserting the cage 5 into the outer cylinder 3. In this linear bushing, a concave groove 32 extending in the longitudinal direction is formed on the outer peripheral surface 12 of the cage 5, and step portions 33 projecting outward from the concave groove 32 at both groove end portions 35 of the concave groove 32. Is formed. On the inner peripheral surface 9 of the end ring 6, a plurality of arc-shaped arc surfaces 18 extending in the longitudinal direction are formed, and a projecting portion 38 projecting inward is formed at the center of the arc surface 18. . The end ring 6 is inserted into the retainer 5 so as to be movable in the longitudinal direction from the end 30 of the retainer 5, and the protrusion 38 of the end ring 6 is engaged with the concave groove 32 of the retainer 5 to retain the end ring 6. The protrusion 38 of the end ring 6 is engaged with the step portion 33 of the container 5, so that the retainer 5 is positioned in the circumferential direction with respect to the retainer 5, and the retainer 5 is positioned and fixed in the longitudinal direction with respect to the outer cylinder 3. It will be. That is, the end ring 6 is positioned in the rotational direction with respect to the cage 5, and the end surface 36 of the end ring 6 abuts against the end surface 31 of the outer cylinder 3 with the shaft 1 being inserted into the cage 5. Will be positioned in the axial direction. In this linear bushing, the arc surface 18 of the end ring 6 is formed at a central position where it is fitted to the corner 15 of the cage 5, and the direction of the cage 5 is on both sides of the arc surface 18 of the end ring 6. An arcuate surface 23 is formed on the inner peripheral surface 9 that covers the turning path concave groove 29 and forms the direction changing path 42. Further, the adjacent arc surface 18 of the end ring 6 extends in the longitudinal direction as a ridge-line projection 39 that protrudes inwardly at the center of the region corresponding to the arc surface 21 of the cage 5.

  This linear bushing is particularly characterized by the arrangement of the circulation path 44 formed in the slider 2, that is, the arrangement of the track path 41, the return path 43, and the direction change path 42 that form the circulation path 44. This linear bushing is provided with a pair of end rings 6 that fit over the entire length of the end portion 30 of the retainer 5 protruding from the end surface 31 of the outer cylinder 3. The outer peripheral surface 12 of the end portion 30 of the cage 5 is incorporated so as to cover the polygonal cross section and abut against the end surface 31 of the outer cylinder 3. The circulation groove 25 formed in the cage 5 is a track groove in which a slit 26 is formed as a window in which the inner peripheral surface 8 extends along the longitudinal direction because the rolling element 4 contacts the track surface 16 of the shaft 1. 27, a return groove 28 extending parallel to the track groove 27 and separated by a partition wall 45, and a pair of direction change paths that connect the track groove 27 and the return groove 28 at the end 30 of the cage 5. It is composed of a concave groove 29. In this linear bushing, the raceway 41 formed by the raceway surface 16 of the shaft 1 and the raceway surface 17 of the outer cylinder 3 in the region of the raceway groove 27 of the cage 5 is loaded with the raceway 41 and the cage 5. The return path 43 formed by the return recess groove 28 and the return path surface 24 of the outer cylinder 3, and the raceway path 41 and the return path 43 communicate with each other, and the direction change path recess groove 29 of the cage 5 and the end ring 6 A circulation path 44 through which the rolling elements 4 circulate infinitely is formed by a direction change path 42 formed with the peripheral surface 9. In this linear bushing, a direction change path groove 29 is formed at the end 30 of the retainer 5 protruding from the end surface 31 of the outer cylinder 3. Although not shown in the drawings, in the conventional linear bushing, relief was formed on the inner peripheral surfaces of both ends of the outer cylinder for the direction change path, but this processing can be omitted in the linear bushing of the present invention. . In particular, the linear bushing is characterized in that the return paths 43 are adjacent to each other and arranged symmetrically in the axial direction of the corner portion 15 with respect to the adjacent circulation paths 44 formed in the slider 2. That is, adjacent circulation grooves 25 formed in the cage 5 are configured by extending the respective return grooves 28 to positions facing each other. In other words, the circulation paths 44 are formed in four rows on the slider 2, and the adjacent two-row circulation paths 44 are in the longitudinal direction of the corner 15 of the cage 5 in which the concave grooves 32 are formed in the circular arc surface 22. Are arranged in line-symmetric positions with respect to the center.

  With regard to this linear bushing, in other words, this linear bushing has a circulation path 44 composed of a track path 41 on which the rolling element ball 4 rolls, a return path 43, and a pair of direction change paths 42 that connect these. It is formed in four rows. The pair of circulation paths 44 at the 0-degree position and the 180-degree position of the cage 5 and the pair of circulation paths 44 at the 90-degree position and the 270-degree position are point-symmetric with respect to the axial center position O of the cage 5. Respectively. In addition, the pair of circulation paths 44 at the 0 degree position and the 90 degree position of the cage 5 and the pair of circulation paths 44 at the 180 degree position and the 270 degree position are P− passing through the axial center position of the cage 5. They are arranged symmetrically with respect to the OP line. In other words, the pair of circulation paths 44 at the 0-degree position and the 90-degree position of the cage 5 and the pair of circulation paths 44 at the 180-degree position and the 270-degree position pass through the axial center position of the cage 5. They are arranged symmetrically with respect to the -O-P line and the Q-O-Q line at 90 degrees. In this linear bushing, the plurality of (four) circulation paths 44 formed in the slider 2 are arranged so that the arrangement of the adjacent circulation paths 44 is line-symmetrical with respect to the axial center of the corner 15 of the cage 5. The arrangement of the raceway 44, the return path 43, and the direction change path 42 constituting the circulation path 44 provided in the slider 2 is alternately changed and arranged around the axis. And the function of preventing the wobbling of the cage 44 is achieved, so that a smooth and stable relative sliding movement of the slider 2 can be achieved.

In this linear bushing, the concave groove 32 of the cage 5 is formed in a trapezoidal cross section. On the end face 34 side of the retainer 5 of the stepped portion 33 formed in the groove end portion 35 of the recessed groove 32, a protrusion 38 of the end ring 6 is positioned in the circumferential direction with respect to the retainer 5 to form the recessed groove 32. A tapered guide groove 40 for engaging and guiding is formed, and the protruding portion 38 of the end ring 6 is elastically deformed in cooperation with the cage 5 to project along the tapered guide groove 40 of the cage 5. It is configured to fit over the recessed groove 32 of the cage 5 over the portion 38. Further, the projection 38 of the end ring 6 is positioned at the center in the longitudinal direction of the end ring 6, and the arc surface 18 of the end ring 6 is symmetrical with respect to the 27 center position of the track groove of the cage 5. Is formed. Further, the end ring 6 is configured to be fitted to either side of the end portion 30 of the cage 5, and the protruding portion 38 is a concave groove from one end portion 30 to the other end portion 30 of the cage 5. It is guided by 32 and can move along the longitudinal direction. Furthermore, in order to test and determine the number of rolling elements 4 incorporated in the circulation groove 25 at the end 30 of the cage 5, a longitudinal length for inserting an inspection member at a position corresponding to the center position of the track groove 27. A through hole 37 extending in the direction is formed in each end face 34.
The through-holes 37 formed in the cage 5 are formed on four end faces 34 at positions corresponding to the center position of the track groove 27 and are formed at positions on the extension line of the track path 41. The shape of 37 may be a round shape or a stepped hole.

  In this linear bushing, the outer cylinder 3, the cage 5 and the end ring 6 can be assembled as follows, for example. The cage 5 has a groove 32 extending over its entire length in the longitudinal direction, and step portions 33 are formed at both groove ends 35 of the groove 32. The cage 5 has a shape in which the groove 32 extends over the entire length between the step portions 33 of the groove end portion 35. Therefore, the pair of end rings 6 can be inserted into the cage 5 from the one end portion 32 side. Regarding this linear bushing, an example in which the outer cylinder 3, the cage 5 and the end ring 6 are assembled by hand will be described. For example, the end ring 6 is fitted into the end 30 on one end side of the cage 5 and assembled. Next, the outer cylinder 3 is inserted and assembled from the end 30 on the other end side of the cage 5. At this time, the outer cylinder 3 can be inserted from one end 30 side where the end ring 6 is inserted into the cage 5. In this case, the end ring 6 fitted to the cage 5 may be moved to the other end 30 of the cage 5. With the end ring 6 and the outer cylinder 3 incorporated in the cage 5, an appropriate number of balls 4 of rolling elements are loaded from the direction change groove 29 of the cage 5 exposed from the outer cylinder 3 into the circulation groove 25. . After assembling the appropriate number of balls 4 into the circulation concave groove 25 of the cage 5, the end ring 6 is fitted into the end 32 on the other end side of the cage 5, and the assembly of the linear bushing is completed.

  Next, another example of the linear bushing when the outer cylinder 3, the cage 5 and the end ring 6 are automatically assembled will be described. For example, a dummy outer cylinder for assembling a linear bushing is prepared, a dummy outer cylinder is inserted from one end side of the cage 5, and the dummy outer cylinder is exposed to the end 30 on the other end side of the cage 5. Include. Next, an appropriate number of balls 4 is loaded into the circulation groove 25 from the direction changing groove 29 of the cage 5 exposed from the dummy outer cylinder. In this linear bushing, since the concave groove 32 extends in the longitudinal direction between the groove end portions 35 in the cage 5, the end ring 6 is inserted into the cage 5 from the one end face 36 side. Can do. Therefore, the end ring 6, the regular outer cylinder 3 and the end ring 6 can be sequentially inserted from one end side of the cage 5, and these can be pushed into the cage 5 to assemble the linear bushing.

  The linear bushing according to the present invention is used by being incorporated in a sliding portion in various apparatuses such as various assembling apparatuses, precision machines, and measurement / inspection apparatuses.

1 axis 2 slider 3 outer cylinder 4 ball (rolling element)
5 Cage 6 End ring 7 Inner peripheral surface (first inner peripheral surface)
8 Inner peripheral surface (third inner peripheral surface)
9 Inner peripheral surface (second inner peripheral surface)
10 outer peripheral surface (first outer peripheral surface)
11 outer peripheral surface (second outer peripheral surface)
12 outer peripheral surface (third outer peripheral surface)
13 Outer peripheral surface (fourth outer peripheral surface)
14 corner (second corner)
15 corner (first corner)
16 Track surface (first track surface)
17 Track surface (second track surface)
18 Arc surface (first arc surface)
19 Arc surface (second arc surface)
20 Arc surface (third arc surface)
21 Arc surface (4th arc surface)
22 Arc surface (5th arc surface)
23 Arc surface (sixth arc surface)
24 Return road surface 25 Circulating groove 26 Slit 27 Track groove 28 Return groove 29 Direction changing path groove 30, 35 End portion 31, 34 End surface 32 Recessed groove 35 Groove end portion 37 Through hole 38 Projection portion 39 Ridge-like projection 40 Taper Guide guide groove 41 Track path 42 Direction change path 43 Return path 44 Circulation path 45 Partition wall

Claims (11)

A long shaft having a circular cross-section with a first raceway surface formed on the first outer peripheral surface, and a relatively slidable portion along the longitudinal direction of the shaft via a ball of a plurality of rolling elements by inserting the shaft. Has a slider,
The slider has a second outer peripheral surface having a circular cross section and a first inner peripheral surface having a substantially square cross section, and extends parallel to the second track surface and the second track surface on which the rolling element can roll along the longitudinal direction. An outer cylinder formed with a return road surface, a retainer having a substantially square cross section that is fitted into the outer cylinder and protrudes from both end surfaces of the outer cylinder, and the retainer that protrudes from the end surface of the outer cylinder A second inner peripheral surface having a substantially quadrangular cross-section over the entire length of the end portion, and a pair of end rings that are in contact with the end surface of the outer cylinder.
The retainer has a plurality of circuit-shaped circulation grooves in which the rolling element rolls and circulates on a third outer peripheral surface having a substantially quadrangular cross section similar to the outer cylinder, and a fourth outer periphery of the end ring. The surface is formed in a circular cross section smaller than the second outer peripheral surface of the outer cylinder,
The circulation ditch of the cage includes a ditch having a third inner circumferential surface formed with a slit extending along a longitudinal direction so that the rolling element contacts the first raceway surface of the shaft, and the raceway ditch. A return groove extending parallel to the groove and separated by a partition wall, and a pair of direction change path grooves communicating the track groove and the return groove at the end of the cage. ,
The slider includes a track path on which the rolling elements formed by the first raceway surface of the shaft and the second raceway surface of the outer cylinder in a region of the raceway groove of the cage are loaded and rolled. A return path formed by the return groove of the retainer and the return road surface of the outer cylinder; and the direction change path recess of the retainer and the end ring that communicate with the track path and the return path. The direction change path formed with the second inner peripheral surface of the circuit forms a circulation path in which the rolling elements circulate infinitely in four rows,
The adjacent circulation paths are linear bushings, each of which is arranged in a line-symmetrical position across the first corner of the cage with the return path alternately opposite to the track path. .   A concave groove extending in the longitudinal direction is formed on the third outer peripheral surface of the retainer, and stepped portions protruding outward from the concave groove are formed at both groove end portions of the concave groove, A plurality of arc-shaped first arc surfaces extending along the longitudinal direction are formed on the second inner peripheral surface, and a protrusion projecting inward is formed at the center of the first arc surface, and the slider The outer cylinder and the cage are positioned in the rotational direction by inserting the cage into the outer cylinder, and the end rings are fitted into the end portions of the cage, respectively. The end ring is positioned in the circumferential direction with respect to the retainer by the projection of the end ring being engaged with the stepped portion of the retainer, and the retainer is in the longitudinal direction with respect to the outer cylinder. The method of claim 1, further comprising positioning and fixing. The placing of the linear bushing.   The outer cylinder has a second arc surface in which the second raceway surface is formed in an R shape on the first inner peripheral surface, and a second corner portion between the second arc surface is formed on the return road surface. The linear bushing according to claim 1, wherein the linear bushing is formed in a substantially square cross section by three arc surfaces.   The retainer is similar to the outer cylinder in a fourth arc surface parallel to the first inner peripheral surface of the outer cylinder and a fifth arc surface of the second corner between the fourth arc surfaces. The linear bushing according to claim 3, wherein the linear bushing is formed on the third outer peripheral surface having a substantially square cross section, and the concave groove is formed along the longitudinal direction of the fourth arc surface of the cage. .   The first arc surface of the end ring is formed at a central position where the first arc surface is fitted to the second corner of the cage, and the direction change path groove of the cage is formed on both sides of the first arc surface. 5. The linear bushing according to claim 3, wherein a sixth arc surface on the second inner peripheral surface that forms the direction change path is formed.   Since the first arc surface adjacent to the end ring extends in the longitudinal direction as a ridge-like projection that protrudes inward and intersects at the center of the region corresponding to the fourth arc surface of the cage. A linear bushing according to claim 5 comprising.   The concave groove of the cage has a trapezoidal cross-sectional shape, and the protrusion of the end ring is formed on the side of the cage end surface of the step formed on the groove end of the concave groove. A tapered guide groove is formed that is circumferentially positioned with respect to the cage and engages and guides into the groove. The protrusion of the end ring is elastically deformed in cooperation with the cage to The linear bushing according to any one of claims 2 to 6, wherein the linear bushing is formed by getting over the protrusion along the tapered guide groove of the cage and fitting into the groove of the cage.   The protrusion of the end ring is positioned at the center in the longitudinal direction of the end ring, and the first arc surface of the end ring is symmetrical with respect to the center position of the track groove of the cage. The linear bushing according to claim 1, wherein the linear bushing is formed.   The end ring is configured to be fitted to either side of the end portion of the cage, and the protruding portion extends from the one end portion to the other end portion of the cage in the concave groove. The linear bushing according to claim 1, wherein the linear bushing is guided and movable along a longitudinal direction.   The longitudinal direction for inserting an inspection member at a position corresponding to the center position of the raceway groove to inspect and determine the number of the rolling elements incorporated in the circulation groove at the end of the cage The linear bushing according to any one of claims 1 to 9, wherein through-holes extending in a straight line are formed on both end faces.   The linear bushing according to any one of claims 1 to 10, wherein the retainer is configured such that adjacent circulation grooves are arranged at positions where the return grooves are opposed to each other.

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