JP4897543B2 - Roller screw - Google Patents

Description

  The present invention relates to a roller screw in which a roller is interposed between a screw shaft and a nut so as to allow rolling motion.

  A ball screw with a ball that allows rolling motion between the screw shaft and the nut can reduce the coefficient of friction when rotating the screw shaft relative to the nut, compared to a screw that makes sliding contact. It has been put to practical use in positioning mechanisms, feed mechanisms, or automobile steering gears.

  In recent years, in order to increase an allowable load, a roller screw using a roller instead of a ball as a rolling element has been developed. As shown in FIG. 16, the applicant has a screw shaft 41 in which a spiral roller rolling groove 41a is formed on the outer peripheral surface and a nut 42 in which a spiral load roller rolling groove is formed on the inner peripheral surface. The roller screw comprised by these is proposed (refer patent document 1). In the load roller rolling path between the load roller rolling groove of the nut 42 and the roller rolling groove 41a of the screw shaft 41, a plurality of rollers are arranged so as to be capable of rolling motion. In order to circulate the roller, the nut 42 is provided with a through hole 42a extending in the axial direction, and the circulation pipe 43 is inserted into the through hole 42a. A direction change path component 44 in which a direction change path is formed is attached to the end face of the nut 42 in the axial direction. Inside the circulation pipe 43, a straight passage 45 for returning the roller is formed. The direction change path 46 connects the load roller rolling path and the straight path 45.

  As shown in FIG. 17, the center line of the track of the load roller rolling path 51 is spiral, the center line of the track of the straight path 52 is a straight line, and the center line of the track of the direction changing path 53 is a curve such as an arc. It is. The roller circulates through a roller circulation path constituted by the load roller rolling path 51, the straight path 52, and the direction changing path 53.

A retainer is interposed between adjacent rollers. In order to move the roller smoothly, the posture of the roller in the roller circulation path needs to be held by the retainer. The applicant has proposed a retainer for a cross arrangement as shown in FIG. The retainer contact surface 55 holds adjacent rollers so that the center line of the adjacent rollers passes through the center line 54 of the screw shaft in the spiral load roller rolling path 51. Further, the retainer contact surface 56 holds the adjacent rollers so that the center line of the adjacent rollers faces the center of the arc of the direction changing path 53 in the arc-shaped direction changing path 53. When the retainer moves from the load roller rolling path to the direction changing path, the contact surfaces 55 and 56 of the retainer are switched.
International Publication No. 2006/051706 Pamphlet

  The arrangement of the rollers in the roller circulation path can be classified into the following three types. The first is an array along the spiral on the load roller rolling path 51, the second is an array along the arc on the direction changing path 53, and the third is an array along the straight line on the straight path 52. is there.

  The conventional retainer corresponds to the first spiral load roller rolling path 51 and the second arcuate direction changing path 53, but does not correspond to the third straight path 52. Absent.

  Accordingly, an object of the present invention is to provide a roller screw including a retainer that can correspond to the arrangement of rollers along a spiral loaded roller rolling path and the arrangement of rollers along a straight path of a no-load roller return path. .

  The present invention will be described below. In addition, in order to make an understanding of this invention easy, the reference number of an accompanying drawing is attached in parenthesis writing, However, This invention is not limited to the form of illustration by it.

  In order to solve the above problems, the invention described in claim 1 is characterized in that a screw shaft (1,33) having a spiral roller rolling portion (1a, 33a) on an outer peripheral surface and the roller rolling on an inner peripheral surface. A nut (2,34) having a spiral load roller rolling part (2a, 34a) facing the running part (1a, 33a), and the load roller rolling part (2a, 34) of the nut (2,34). 34a) has a no-load roller return passage (11, 13, 36) connecting one end and the other end, and a straight passage (straight line) linearly extending to a part of this no-load roller return passage (11, 13, 36) 11, 36), circulating parts (8, 9, 31) including the load roller rolling part (2a, 34a) of the nut (2, 34) and the roller rolling of the screw shaft (1, 33). Roller circulation composed of a loaded roller rolling path (3) between the running section (1a, 33a) and the no-load roller return passage (11, 13, 36) of the circulating component (8, 9, 31) A plurality of rollers (4) arranged in a path, and a plurality of retainers (5) interposed between the plurality of rollers (4), Each side surface (5a) of the retainer (5) that contacts the roller (4), the retainer (5) in the state where the retainer (5) is arranged in the load roller rolling path (3) An inner peripheral side area (23) which is the inner peripheral side of the roller rolling path (3), and an outer peripheral side area (24) which is the outer peripheral side of the load roller rolling path (3), and the retainer (5) The inner peripheral area (23) is such that the distance between adjacent rollers (4) in the load roller rolling path (3) is smaller on the inner peripheral side of the load roller rolling path (3) and larger on the outer peripheral side. The adjacent roller (4) is held in the outer periphery side section (24) of the retainer (5), and the center line of the adjacent roller (4) is the straight line (11, 36). The roller screw is characterized in that the adjacent rollers (4) are held so as to be arranged in parallel when viewed from the side of the straight path (11, 36).

  According to a second aspect of the present invention, in the roller screw according to the first aspect, the linear passage (11, 36) is twisted, and the outer peripheral side section (24) of the retainer (5) is twisted. In the linear path (11, 36), the adjacent roller (4) is held so that the adjacent roller (4) corresponds to the twisted linear path (11, 36). To do.

  According to a third aspect of the present invention, in the roller screw according to the second aspect, the inner peripheral side area (23) of each side surface (5a) of the retainer (5) is a side surface shape of the roller (4). The outer peripheral side area (24) of each side surface (5a) of the retainer (5) is a pair of side surfaces corresponding to the side surface shape of the roller (4). It has a curved recess (24b) and a planar relief surface (24a) provided between the pair of curved recesses (24b).

The invention according to claim 4 includes a screw shaft (1, 33) having a spiral roller rolling part (1a, 33a) on the outer peripheral surface, and the roller rolling part (1a, 33a) on the inner peripheral surface. Nuts (2,34) having opposing spiral load roller rolling portions (2a, 34a), and one end and the other end of the load roller rolling portion (2a, 34a) of the nut (2,34) Circulation including a no-load roller return path (11, 13, 36) to be connected and a linear path (11, 36) extending linearly in a part of the no-load roller return path (11, 13, 36) Parts (8, 9, 31), the loaded roller rolling part (2a, 34a) of the nut (2, 34) and the roller rolling part (1a, 33a) of the screw shaft (1, 33) A plurality of rollers arranged in a roller circulation path composed of a loaded roller rolling path (3) between and the no-load roller return path (11, 13, 36) of the circulation component (8, 9, 31) (4) and a plurality of retainers (5) interposed between the plurality of rollers (4), the linear passage (11, 36) The retainer (5) is twisted, and in the twisted linear passage (11, 36), the center lines of the adjacent rollers (4) are arranged in parallel when viewed from the side of the linear passage (11, 36), And the adjacent rollers (4) are held so that the adjacent rollers (4) correspond to the twisted linear passages (11, 36), and both side surfaces (5a) of the retainer (5), respectively. Has a pair of curved concave portions (24b) corresponding to the side surface shape of the roller (4), and a planar relief surface (24a) provided between the pair of curved concave portions (24b). a roller screw according to claim.

According to a fifth aspect of the present invention, in the roller screw according to any one of the first to fourth aspects, the retainer (5) arranged in the loaded roller rolling path (3) is disposed on the retainer (5). A mark (26) for distinguishing between the inner peripheral side and the outer peripheral side is provided.

According to a sixth aspect of the present invention, in the roller screw according to any one of the first to fifth aspects, the circulating component (8, 9) is a through hole (7) penetrating the nut (2) in the axial direction. A circulation pipe (8) having a linear passage (11, 36) provided in the linear passage (11, 36) and an end face in the axial direction of the nut (2), and the load roller roller of the nut (2). A direction change path component (9) having a direction change path (13) that connects the running section (2a) and the straight path (11) of the circulation pipe (8).

According to a seventh aspect of the present invention, in the roller screw according to any one of the first to fifth aspects, the circulating component (31) is attached to a side surface of the nut (34), and the unloaded roller return is provided inside. It is a return pipe (31) in which the passage (36) is formed.

  According to the first aspect of the present invention, the retainer holds the arrangement of the rollers along the spiral in the load area and the arrangement of the rollers along the straight line in the no-load area. The spiral load roller rolling path and the direction changing path are common in that they are curved. If the posture of the roller on the spiral load roller rolling path can be maintained, the posture of the roller can be maintained to some extent even on the direction change path. Therefore, the roller moves smoothly along the roller circulation path.

  According to the second aspect of the present invention, the retainer maintains the posture of the roller so as to correspond to the twisted linear path, so that the roller smoothly moves even in the twisted linear path.

  According to the third aspect of the present invention, the retainer can hold the adjacent rollers so that the adjacent rollers are twisted.

According to the fourth aspect of the present invention, since the retainer maintains the posture of the roller so as to correspond to the twisted linear path, the roller smoothly moves even in the twisted linear path. Further, the retainer can hold the adjacent rollers so that the adjacent rollers are twisted.

According to the fifth aspect of the present invention, since the inner peripheral side and the outer peripheral side of the retainer can be distinguished, the work of incorporating the retainer into the roller circulation path is facilitated.

The roller circulation path may be a so-called end cap system as described in claim 6 , or may be a return pipe system as described in claim 7 .

  FIG.1 and FIG.2 shows the perspective view of the roller screw in one Embodiment of this invention. FIG. 1 is a perspective view (including a partial cross-sectional view) of a roller screw, and FIG. 2 is an enlarged view (including a partial cross-sectional view) of a circulating portion of the roller screw. In these drawings, the end piece 16 of the direction change path component is removed so as to show the circulation state of the roller.

  The roller screw includes a screw shaft 1 having a spiral roller rolling groove 1a formed on the outer peripheral surface, and a nut having a spiral load roller rolling groove 2a facing the roller rolling groove 1a on the inner peripheral surface. 2 is provided. A plurality of rollers 4 are arranged in a spiral load roller rolling path 3 between the roller rolling groove 1 a of the screw shaft 1 and the load roller rolling groove 2 a of the nut 2. Between the rollers 4, a retainer 5 that prevents contact between adjacent rollers 4 is interposed.

  The screw shaft 1 is formed by cutting and grinding or rolling a spiral roller rolling groove 1a having a predetermined lead on the outer peripheral surface of a steel bar such as carbon steel, chrome steel, or stainless steel. . The number of strips in the roller rolling groove 1a may be one, two or three. The roller 4 used for the roller screw of this embodiment is cylindrical. The roller rolling groove 1a has a V-shaped cross section and an opening angle of about 90 degrees so that a load roller rolling path 3 having a square cross section can be formed together with the load roller rolling groove 2a of the nut 2.

  The nut 2 is formed by cutting and grinding or rolling a spiral load roller rolling groove 2a having a predetermined lead on the inner peripheral surface of a cylinder such as carbon steel, chrome steel, or stainless steel. is there. The load roller rolling groove 2a has a V-shaped cross section and an opening angle of about 90 degrees. A flange 6 for attaching the nut 2 to the mating part is formed at the end of the outer periphery of the nut 2 in the axial direction.

  A through hole 7 extending in the axial direction of the nut 2 is formed in the nut 2. A circulation pipe 8 is inserted into the through hole 7. Inside the circulation pipe 8, a straight passage 11 is formed that extends linearly in the axial direction of the nut 2. The linear passage 11 has a square cross section and is twisted so that the posture of the roller 4 moving in the linear passage 11 can be rotated. The cross-sectional shape of the straight passage 11 is a quadrangle corresponding to the side shape of the roller 4. In this embodiment, since the side surface shape of the roller 4 is square, the cross-sectional shape of the linear passage 11 is also square.

  On both end surfaces of the nut 2 in the axial direction, mounting recesses 2b (see FIG. 3) connected to the through holes are formed. The direction change path component 9 is attached to the mounting recess 2b. Inside the direction change path component 9, a direction change path 13 extending in a curved shape such as an arc is formed. The direction change path 13 is provided at both ends of the linear straight path 11, and connects the linear path 11 and the spiral load roller rolling path 3. In this embodiment, the number of the circulation pipes 8 and the direction change path components 9 equal to the number of the roller rolling grooves 1a are provided.

  The direction change path 13 of the circulation pipe 8 and the straight path 11 of the direction change path component 9 constitute an unloaded roller return path. The circulation pipe 8 and the direction change path component 9 constitute a circulation component.

  A plurality of rollers 4 are arranged as rolling elements in a roller circulation path composed of the load roller rolling path 3, the direction change path 13 of the direction change path component 9, and the straight path 11 of the circulation pipe 8. The roller 4 is cylindrical and has substantially the same diameter and length. Precisely, the diameter of the roller 4 is slightly larger than the height of the roller 4. For this reason, the shape of the roller 4 seen from the side is close to a square. The rollers 4 are arranged in parallel so that the axes of the adjacent rollers 4 are substantially parallel in the roller circulation path. In addition, in the spiral load roller rolling path 3, since the axis of the roller 4 passes through the center line of the screw shaft 1, strictly speaking, the axis of the adjacent roller 4 is not parallel. In order to include such a case, the axes of the adjacent rollers 4 are substantially parallel. A plurality of retainers 5 that hold the posture of the rollers 4 are interposed between the plurality of rollers 4. The structure of the retainer 5 will be described later.

  When the screw shaft 1 is rotated relative to the nut 2, the plurality of rollers 4 move while rolling between the roller rolling groove 1 a and the load roller rolling groove 2 a. The roller 4 that has rolled to one end of the load roller rolling path 3 is lifted up by the lifting portion 15 (see FIG. 7) of the direction change path component 9 and guided into the direction change path 13. Then, after passing through the straight path 11 and the opposite direction change path 13, the sheet again enters between the roller rolling groove 1a and the load roller rolling groove 2a.

  FIG. 3 shows the roller screw viewed from the axial direction of the screw shaft 1, and FIG. 4 shows the roller screw viewed from the side of the screw shaft 1. Also in these drawings, the end piece 16 of the direction change path component 9 is removed to show the roller 4 inside the direction change path component 9. As shown in FIG. 3, when viewed from the axial direction of the screw shaft 1, the center line 13 a of the direction change path 13 is disposed in the tangential direction of the screw shaft 1. The center line 13a of the direction change path 13 on the front side of the page intersects with the center line 13a of the rear direction change path 13 (not shown) at a predetermined opening angle α. The straight path 11 rotates the posture of the roller 4 by an angle α equal to the opening angle. Thereby, the attitude | position of the roller 4 which transfers to the load roller rolling path 3 can be match | combined with the cross-sectional shape of the load roller rolling path 3. FIG. As shown in FIG. 4, when viewed from the side of the screw shaft 1, the tip end portion of the direction changing path 13 is arranged in accordance with the lead angle direction of the screw shaft 1.

  Note that seals may be attached to both end faces of the nut 2 in the axial direction in order to remove foreign substances and to prevent the lubricant from leaking from the inside of the nut 2.

  5 and 6 show the direction change path component 9 and the circulation pipe 8 incorporated in the nut 2. The direction change path component 9 is formed by combining an R piece 17 on the inner peripheral side of the direction change path 13 and an end piece 16 on the outer peripheral side of the direction change path 13. The circulation pipe 8 is formed by joining divided pieces 18a and 18b which are divided into two in the axial direction. Both end surfaces in the axial direction of the circulation pipe 8 are formed in a plane. An end surface of the circulation pipe 8 becomes a joint surface 8 a with the direction change path component 9. A plurality of (for example, four) positioning holes 19 are machined on the joint surface 8a of the circulation pipe 8 at an equal interval in the circumferential direction on a circumference having a constant radius. The joining surface 9a of the direction change path component 9 joined to the circulation pipe 8 is also formed in a plane (see FIG. 7). A plurality of (for example, four) positioning holes 20 are also machined on the joint surface 9a of the direction change path component 9 on the circumference having a constant radius at equal intervals in the circumferential direction. Positioning pins 21 are inserted into the positioning holes 19 and 20. The positioning pin 21 is manufactured with high accuracy so that there is no gap between the positioning holes 19 and 20 and the positioning pin 21. It is desirable that the positioning pin 21 and the positioning holes 19 and 20 have an interference fit with a tightening margin.

  When joining the direction change path component 9 to the circulation pipe 8, an adhesive or the like is applied in advance to the positioning pin 21, and positioning is performed in one of the positioning holes 19 and 20 of the direction change path component 9 and the circulation pipe 8. The pin 21 is inserted. Then, the one where the positioning pin 21 is inserted is brought close to the other one, and the positioning pin 21 is inserted into the remaining one positioning hole 19, 20.

  In this embodiment, the positioning holes 19 and 20 are provided in both the direction changing path component 9 and the circulation pipe 8, but the positioning holes 19 and 20 are provided only in either the direction changing path component 9 or the circulation pipe 8. 20 may be provided, and the positioning pin 21 may be integrally formed on the other side.

  FIG. 7 shows a perspective view of the direction change path component 9. A direction change path 13 is formed in the direction change path component 9. The direction change path 13 has a square cross section. The direction change path 13 extends in an arc shape, but is not twisted. This is because if the arcuate direction change path 13 is twisted, the roller 4 may be clogged because it is twisted while being bent. The direction change path component 9 is divided into an inner peripheral R piece 17 and an outer end end piece 16 along diagonal vertices 13c and 13d of the direction change path 13 having a square cross section. The direction change path component 9 is provided with a lifting portion 15 that scoops up the roller 4 moving on the load roller rolling path 3 into the direction change path 13. The direction changing path 13 changes the direction of the roller 4 raised by the lifting unit 15 and guides it to the straight path 11.

  As shown in FIG. 5, the R piece 17 and the end piece 16 are overlapped, the bolts are passed through the flange portions 16 a, 17 a, and the bolts are fitted into the screw holes 23 formed in the recesses 2 b on the end face of the nut 2. Then, the direction change path component 9 is attached to the nut 2.

  8 and 9 show the circulation pipe 8. FIG. 8 shows a perspective view of the circulation pipe 8, and FIG. 9 shows a twisted straight passage 11 of the circulation pipe 8. A straight passage 11 having a square cross section is formed inside the cylindrical circulation pipe 8. The straight passage 11 is twisted so that the posture of the moving roller 4 can be rotated. In this embodiment, the outlet of the straight passage 11 is twisted nearly 90 degrees with respect to the inlet. A plurality of positioning holes 19 are processed in both end faces of the circulation pipe 8. The circulation pipe 8 is formed by joining a pair of divided pieces 18 a and 18 b divided into two along the vertices 11 a and 11 b of the diagonal line of the straight passage 11. The divided pieces 18a and 18b may be manufactured by cutting, or may be resin molded products.

  FIG. 10 shows the locus of the center line of the roller circulation path. The roller circulation path includes a spiral load roller rolling path 3, a linear path 11 extending linearly, and a direction changing path 13 extending in an arc shape. The trajectory of the center line at the connection point of these paths is continuous and the tangent line of the trajectory is continuous so that the rollers can smoothly move.

  As shown in FIG. 10A, the locus of the center line of the spiral load roller rolling path 3 as seen from the axial direction of the screw shaft 1 is a circle. When viewed from the axial direction of the screw shaft 1, the plurality of rollers 4 are arranged in the load roller rolling path 3 so that the center line thereof faces the center line of the screw shaft.

  As shown in FIG. 10B, the locus of the center line of the direction change path 13 is an arc. The plurality of rollers 4 are arranged in the direction change path 13 so that the center line thereof faces the center of the arc.

  As shown in FIG. 10 (B), the locus of the center line of the straight passage 11 is a straight line. The plurality of rollers 4 are arranged in the straight path 11 so that the center lines are arranged in parallel when viewed from the side of the straight path 11.

  FIG. 11 shows the retainer 5 interposed between the adjacent rollers 4. The retainer 5 has side surfaces that contact the roller 4 at both ends in the traveling direction.

  12 and 13 are detailed views of the retainer 5. FIG. 12 shows a perspective view of the retainer 5, and FIG. 13 shows a three-view view of the retainer 5. Each of the both side surfaces 5a of the retainer 5 that contacts the roller 4 is divided into an inner peripheral area 23 on the left side and an outer peripheral area 24 on the right side in FIG. The inner peripheral area 23 is on the inner peripheral side of the load roller rolling path 3 in a state where the retainers 5 are arranged in the load roller rolling path 3. On the other hand, the outer peripheral side area 24 is on the outer peripheral side of the load roller rolling path 3. The inner peripheral side area 23 and the outer peripheral side area 24 are partitioned by a boundary line 25.

  The inner peripheral side area 23 has a curved concave portion 23 a corresponding to the side shape of the roller 4. Since the roller 4 is cylindrical, the curved concave portion 23a also forms a part of the cylinder. The radius of curvature of the curved concave portion 23 a is equal to the radius of the roller 4 or slightly larger than the radius of the roller 4. A pair of relief curved surfaces 23b having a radius of curvature larger than the radius of the roller 4 is formed on both sides of the curved concave portion 23a.

  The outer peripheral side area 24 has a pair of curved concave portions 24b corresponding to the side surface shape of the roller 4, and a planar relief surface 24a provided between the pair of curved concave portions 24b. The radius of curvature of the curved concave portion 24 b is equal to the radius of the roller 4 or slightly larger than the radius of the roller 4. In this embodiment, the planar flank 24a is formed in a triangular shape. A pair of relief surfaces 24a formed on both side surfaces 5a of the retainer 5 are parallel to each other.

  On the outer peripheral side surface 5b of the retainer 5, a mark 26 is attached to distinguish the outer peripheral side and the inner peripheral side of the retainer 5. If the inner peripheral side and the outer peripheral side of the retainer 5 can be easily distinguished by the mark, the work of incorporating the retainer 5 into the load roller circulation path becomes easy. The mark 26 may be attached to the side surface 5 c on the inner peripheral side of the retainer 5.

  FIG. 14 shows the rollers 4 arranged in the roller circulation path. 14A shows the rollers 4 arranged in the loaded roller rolling path 3, and FIG. 14B shows the rollers 4 arranged in the straight passage 11 of the circulation pipe 8. In the loaded roller rolling path 3, the roller 4 comes into contact with the inner peripheral side area 23 of the side surface 5 a of the retainer 5. And the inner peripheral side area 23 of the retainer 5 holds the adjacent rollers 4 so that the distance between the adjacent rollers 4 is smaller on the inner peripheral side of the load roller rolling path 3 and larger on the outer peripheral side. Thereby, the center line of the roller 4 comes to face the center of the screw shaft 1.

  On the other hand, as shown in FIG. 14B, in the linear passage 11, the roller 4 comes into contact with the outer peripheral side area 24 on the side surface of the retainer 5. And the outer peripheral side area | region 24 of the retainer 5 hold | maintains the said adjacent roller 4 so that the centerline of the adjacent roller 4 may be located in parallel seeing from the side of the linear channel | path 11. FIG. Further, since the linear passage 11 is twisted, the adjacent rollers 4 are held so that the adjacent rollers 4 correspond to the twisted linear passage 11. That is, the outer peripheral side section 24 of the retainer 5 holds the roller 4 so that the center lines of the front and rear rollers 4 intersect as seen from the traveling direction of the roller 4. The twist angle of the front and rear rollers 4 is an angle obtained by dividing the total twist angle of the straight path 11 by the number of rollers 4 arranged in the straight path 11. Further, the flank face of the outer peripheral side section 24 is formed in a plane so as not to interfere with the roller 4 when the posture is changed so that the roller 4 in contact with the outer peripheral side section 24 is twisted.

  Assuming that the center lines of the adjacent rollers 4 are inclined with respect to each other when viewed from the side of the straight path 11, the end surfaces of the rollers 4 move while sliding on the wall surface of the straight path 11, so that there is a risk of catching. In particular, when the straight passage 11 is twisted, the possibility of being caught becomes larger. Therefore, in the straight path 11, the center lines of the adjacent rollers 4 are kept parallel, and the adjacent rollers 4 are kept in a twisted state.

  According to this embodiment, the retainer 5 holds the arrangement of the rollers 4 along the spiral in the load area and the arrangement of the rollers 4 along the straight line in the no-load area. The spiral load roller rolling path 3 and the direction changing path 13 are common in that they are curved. The ratio of the load roller rolling path 3 to the entire length of the roller circulation path is larger than the ratio of the direction changing path 13. If the posture of the roller 4 in the spiral load roller rolling path 3 can be maintained, the orientation of the roller 4 can be maintained to some extent even in the direction changing path 13.

  FIG. 15 shows a roller screw according to the second embodiment of the present invention. In the roller screw of this embodiment, a return pipe 31 is provided instead of the direction change path component 9 and the circulation pipe 8, and the roller 32 is circulated by the return pipe 31. The roller screw includes a screw shaft 33 having a spiral roller rolling groove 33a on the outer peripheral surface, and a nut 34 having a spiral load roller rolling groove 34a facing the roller rolling groove 33a on the inner peripheral surface. Prepare. A through hole 35 is formed in the side surface of the nut 34. The return pipe 31 is inserted into the through hole 35.

  A no-load roller return path is formed in the return pipe 31. The no-load roller return path connects the one end and the other end of the load roller rolling groove 34a of the nut 34 so that the roller 32 can be circulated, and includes a straight path 36. A plurality of rollers 32 are cross-arranged in the roller circulation path including the loaded roller rolling groove 34 a of the nut 34 and the unloaded roller return path of the return pipe 31. That is, when viewed from the traveling direction of the rollers 32, the axes of the adjacent rollers 32 are orthogonal.

  The straight passage 36 of the no-load roller return passage in the return pipe 31 has a square cross section and is twisted. And the retainer 5 is interposed between rollers similarly to the roller screw of 1st embodiment. Since the structure of the retainer 5 is the same as that of the first embodiment, the same reference numerals are given and the description thereof is omitted.

  The present invention is not limited to the above-described embodiment, and can be variously modified without changing the gist of the present invention. For example, a tapered roller having a tapered side surface may be used as the roller instead of the cylindrical roller. The ratio of the diameter and height of the roller can be appropriately set according to the load. The rollers may be arranged in parallel as in the above embodiment or in a cross arrangement.

  Moreover, in the said embodiment, although the flat flank is formed in the outer peripheral side area of the side surface of a retainer, when a linear channel is twisted by a fixed ratio, it is not necessary to form a flank. This is because the torsion angle of the rollers before and after moving in the straight path becomes constant.

The perspective view (including partial sectional view) of the roller screw in one embodiment of the present invention Enlarged view of the main part of the roller screw Front view of roller screw (including partial cross-sectional view) Side view of roller screw (including partial cross-sectional view) The perspective view which shows the direction change path component assembled in a nut, and a circulation pipe Perspective view of direction change path components and circulation pipe Perspective view of direction change path components Perspective view of circulating parts Diagram showing twisted straight passage The figure which shows the locus | trajectory of the centerline of a roller circulation path | route ((A) in a figure shows the state seen from the axial direction of a screw shaft, (B) in the figure shows the state seen from the side of a screw shaft) A perspective view showing a retainer interposed between adjacent rollers Retainer perspective view Three views of retainer ((A) is a plan view, (B) is a side view, (C) is a front view of the outer periphery side) The figure which shows the roller arranged in a roller circulation path ((A) in the figure shows the roller arranged in a load roller rolling path, (B) shows the roller arranged in the linear path of a circulation pipe) The perspective view (including a partial sectional view) showing the roller screw in the second embodiment of the present invention An exploded perspective view showing a conventional roller screw The figure which shows the locus | trajectory of the centerline of a roller circulation path | route ((A) in a figure shows the state seen from the axial direction of a screw shaft, (B) in the figure shows the state seen from the side of a screw shaft) A perspective view showing a conventional retainer

Explanation of symbols

1 ... Screw shaft 1a ... Roller rolling groove (roller rolling part)
2 ... Nut 2a ... Loaded roller rolling groove (Loaded roller rolling part)
DESCRIPTION OF SYMBOLS 3 ... Load roller rolling path 4 ... Roller 5 ... Retainer 5a ... Both sides 7 ... Through-hole 8 ... Circulation pipe (circulation component)
9 ... Direction change path components (circulation parts)
DESCRIPTION OF SYMBOLS 11 ... Straight path 13 ... Direction change path 23 ... Inner peripheral side area 23a ... Curved recessed part 24 of inner peripheral side area ... Outer peripheral side area 24a ... Flank 24b ... Curved concave part 26 of outer peripheral side area ... Mark 31 ... Return pipe (Circulating parts)
32 ... Roller 33a ... Roller rolling groove (roller rolling part)
33 ... Screw shaft 34 ... Nut 34a ... Load roller rolling groove (load roller rolling part)
36 ... Straight passage

Claims (7)

A screw shaft having a spiral roller rolling part on the outer peripheral surface;
A nut having a spiral load roller rolling part facing the roller rolling part on the inner peripheral surface;
A circulating component including a no-load roller return passage connecting one end and the other end of the load roller rolling portion of the nut, and including a linear passage extending linearly in a part of the no-load roller return passage;
It is arranged in a roller circulation path composed of a loaded roller rolling path between the loaded roller rolling section of the nut and the roller rolling section of the screw shaft, and the no-load roller return path of the circulating component. Multiple rollers,
A plurality of retainers interposed between the plurality of rollers,
Each of both side surfaces of the retainer that contacts the roller includes an inner peripheral area that is an inner peripheral side of the load roller rolling path in a state where the retainer is arranged in the load roller rolling path, and the load roller. Including the outer peripheral side area that becomes the outer peripheral side of the rolling path,
The inner peripheral side section of the retainer holds the adjacent rollers in the load roller rolling path so that the distance between adjacent rollers is small on the inner peripheral side of the load roller rolling path and large on the outer peripheral side. ,
The outer peripheral side section of the retainer holds the adjacent rollers in the linear path so that the center lines of the adjacent rollers are aligned in parallel when viewed from the side of the linear path. . The straight passage is twisted;
The said outer peripheral side area | region of the said retainer hold | maintains the said adjacent roller so that the said adjacent roller may be in the state corresponding to the said linear path twisted in the said twisted linear path. Roller screw as described in. The inner peripheral side area of each side surface of the retainer has a curved concave portion corresponding to the side surface shape of the roller,
The outer peripheral side area of each side surface of the retainer has a pair of curved concave portions corresponding to the side surface shape of the roller, and a planar relief surface provided between the pair of curved concave portions. The roller screw according to claim 2, wherein A screw shaft having a spiral roller rolling part on the outer peripheral surface;
A nut having a spiral load roller rolling part facing the roller rolling part on the inner peripheral surface;
A circulating component including a no-load roller return passage connecting one end and the other end of the load roller rolling portion of the nut, and including a linear passage extending linearly in a part of the no-load roller return passage;
It is arranged in a roller circulation path composed of a loaded roller rolling path between the loaded roller rolling section of the nut and the roller rolling section of the screw shaft, and the no-load roller return path of the circulating component. Multiple rollers,
A plurality of retainers interposed between the plurality of rollers,
The straight passage is twisted;
The retainer is arranged in such a manner that, in the twisted linear path, the center lines of adjacent rollers are aligned in parallel when viewed from the side of the linear path, and the adjacent rollers correspond to the twisted linear path. Holding adjacent rollers ,
Each of the both side surfaces of the retainer has a pair of curved concave portions corresponding to the shape of the side surface of the roller , and a planar relief surface provided between the pair of curved concave portions. . The mark for distinguishing the inner peripheral side and outer peripheral side of the said retainer arranged in the said load roller rolling path is given to the said retainer, The Claim 1 thru | or 4 characterized by the above-mentioned. Roller screw. The circulating component is
A circulation pipe provided in a through-hole penetrating the nut in the axial direction and having the linear passage extending linearly;
A direction change path component having a direction change path that is attached to the axial end face of the nut and connects the load roller rolling portion of the nut and the linear path of the circulation pipe;
Roller screw according to any one of claims 1 to 5, characterized in that it comprises. The circulating component is
The mounted to the side of the nut, the roller screw according to any one of claims 1 to 5, characterized in that a return pipe to the unloaded roller return path is formed inside.

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