WO2017043277A1 - Ball-screw type drive device and movable-body floating unit - Google Patents

Ball-screw type drive device and movable-body floating unit Download PDF

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Publication number
WO2017043277A1
WO2017043277A1 PCT/JP2016/074010 JP2016074010W WO2017043277A1 WO 2017043277 A1 WO2017043277 A1 WO 2017043277A1 JP 2016074010 W JP2016074010 W JP 2016074010W WO 2017043277 A1 WO2017043277 A1 WO 2017043277A1
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WO
WIPO (PCT)
Prior art keywords
rolling element
rolling
element arrangement
arrangement groove
groove
Prior art date
Application number
PCT/JP2016/074010
Other languages
French (fr)
Japanese (ja)
Inventor
弘幸 岸
勉 富樫
旭 石原
Original Assignee
Thk株式会社
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Application filed by Thk株式会社 filed Critical Thk株式会社
Publication of WO2017043277A1 publication Critical patent/WO2017043277A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
    • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
    • F16H25/20—Screw mechanisms
    • F16H25/22—Screw mechanisms with balls, rollers, or similar members between the co-operating parts; Elements essential to the use of such members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
    • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
    • F16H25/20—Screw mechanisms
    • F16H25/24—Elements essential to such mechanisms, e.g. screws, nuts

Definitions

  • the present invention relates to a ball screw type driving device and a movable body floating unit.
  • Patent Document 1 discloses a ball screw type driving device.
  • This ball screw type driving device includes a nut member on a movable body supported movably by a guide portion. By reciprocating rotation of the screw shaft screwed to the nut member, the movable body is driven to reciprocate along the guide portion via the nut member.
  • the ball screw type driving device includes a mounting bolt fixed to the movable body in a substantially equal circumferential direction and loosely fitted in a mounting hole of the nut member, and a first thrust interposed between the movable body and the nut member.
  • the second thrust bearing interposed between the bearing and the nut member and the mounting bolt supports the nut member movably in the radial direction with respect to the movable body, and absorbs vibration during rotation of the screw shaft.
  • the ball screw type driving device having the above configuration has a thrust bearing between the nut member and the movable body. For this reason, the mounting bolt fixed to the movable body is inserted into the mounting hole of the nut member, and the rotation of the nut member is regulated by the mounting bolt (see paragraph 0023 of Patent Document 1). However, when the rotation of the thrust bearing is restricted by the mounting bolt, the mounting bolt and the nut member are constrained, so that the vibration during rotation of the screw shaft is directly transmitted to the movable body via the nut member and the mounting bolt. Thus, in the above configuration, the floating function of the thrust bearing does not make sense, and there is a possibility that vibration during rotation of the screw shaft cannot be absorbed.
  • the present invention provides a ball screw type driving device and a movable body floating unit capable of restricting the rotation of a nut member and absorbing a vibration during rotation of a screw shaft transmitted to the movable body.
  • a ball screw type driving device includes a screw shaft having a spiral rolling element rolling groove on an outer peripheral surface, and a spiral shape facing the rolling element rolling groove on an inner peripheral surface.
  • a nut member having a rolling element load rolling groove, a plurality of first rolling elements interposed between the rolling element rolling groove and the rolling element load rolling groove, and a movable movable together with the nut member A body, a guide portion that supports the movable body so as to be movable in an axial direction in which the screw shaft extends, and a connection that couples the nut member and the movable body via a plurality of second rolling elements in the axial direction.
  • a vessel A vessel.
  • the coupler includes a rolling element arrangement groove that arranges the plurality of second rolling elements in a circumferential direction of the screw shaft.
  • the rolling element arrangement groove is formed in a non-circular shape when viewed from the axial direction or a circular shape whose center does not coincide with the axis of the screw shaft as viewed from the axial direction.
  • the nut member may be integrally provided with a plate-like flange portion.
  • the rolling element arrangement groove includes a first rolling element arrangement groove disposed on one surface side in the axial direction of the flange portion and a second surface disposed on the other surface side in the axial direction of the flange portion. And rolling element arrangement grooves.
  • the coupler has a pair of plate members that sandwich the flange portion via the plurality of second rolling elements arranged in the first rolling element arrangement groove and the second rolling element arrangement groove, At least one of the pair of plate members may have an attachment portion that is detachably attached to the movable body.
  • the coupler may have an attachment plate that is detachably attached to the movable body.
  • the rolling element arrangement groove includes a first rolling element arrangement groove disposed on one surface of the mounting plate in the axial direction and a second rolling element disposed on the other surface of the mounting plate in the axial direction. And a moving body arranging groove.
  • the coupler has a pair of plate members that sandwich the mounting plate via the plurality of second rolling elements arranged in the first rolling element arrangement groove and the second rolling element arrangement groove, At least one of the pair of plate members may have an attachment portion that is detachably attached to the nut member.
  • each of the first rolling element arrangement groove and the second rolling element arrangement groove has a predetermined contact angle with respect to the radial direction of the screw shaft. You may contact a rolling element.
  • the contact angle of the first rolling element arrangement groove and the second rolling element arrangement groove may be set to a front combination angular type.
  • the contact angle ⁇ of the first rolling element arrangement groove and the second rolling element arrangement groove is: 45 ° ⁇ ⁇ 90 ° May be satisfied.
  • the movable body floating unit provided in the ball screw type driving device includes a screw shaft having a spiral rolling element rolling groove on the outer peripheral surface, and the rolling element rolling unit on the inner peripheral surface.
  • a coupler coupled via a moving body.
  • the coupler includes a rolling element arrangement groove that arranges the plurality of second rolling elements in a circumferential direction of the screw shaft.
  • the rolling element arrangement groove is formed in a non-circular shape when viewed from the axial direction or a circular shape whose center does not coincide with the axis of the screw shaft as viewed from the axial direction.
  • the rotation of the nut member can be restricted and the vibration during rotation of the screw shaft transmitted to the movable body can be absorbed.
  • FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 of the present invention. It is a perspective view of a nut member provided with a connector in a 1st embodiment of the present invention. It is a perspective view of nut member 3 which removed a pair of board members in a 1st embodiment of the present invention. It is the figure which looked at the rolling element arrangement
  • FIG. 1 is a plan view of a ball screw type driving device 1 according to a first embodiment of the present invention.
  • 2 is a cross-sectional view taken along line AA in FIG.
  • the ball screw type driving device 1 includes a screw shaft 2, a nut member 3, a ball 4 (first rolling element), a movable body 5, a guide portion 6, and a connection. And a container 7.
  • the screw shaft 2 has a spiral ball rolling groove 21 (rolling element rolling groove) on the outer peripheral surface 2a as shown in FIG. As shown in FIG. 1, both ends of the screw shaft 2 are rotatably supported via a bearing 9 with respect to the base portion 8 of the ball screw type driving device 1. One end of the screw shaft 2 is connected to the motor 10. The motor 10 is supported by a support member 12 fixed to the base portion 8. The motor 10 rotates the screw shaft 2 around its axis C.
  • the nut member 3 has a spiral ball load rolling groove 31 (rolling element load rolling groove) on the inner peripheral surface 3b.
  • the ball load rolling groove 31 faces the ball rolling groove 21.
  • the ball load rolling path 13 is formed in the facing portion.
  • the ball 4 is interposed between the ball rolling groove 21 and the ball load rolling groove 31.
  • the ball 4 rolls under a load on the ball load rolling path 13.
  • the nut member 3 has rolling element circulation parts (not shown) such as a return pipe.
  • the rolling element circulation component has a rolling element circulation path and connects one end and the other end of the ball load rolling path 13. When one end and the other end of the ball load rolling path 13 are connected, an infinite circulation path of the ball 4 is formed. That is, the ball 4 rolls to the other end (tail) of the ball load rolling path 13, then moves in the rolling element circulation component, and is introduced again to one end (lead) of the ball load rolling path 13.
  • the movable body 5 is a movable table having a rectangular shape in a plan view in which a bracket 5a is disposed at the center thereof.
  • the bracket 5a is provided with a plurality of screw holes 5a1, and is fixed to the table portion of the movable body 5 by bolts (not shown).
  • the coupler 7 mentioned later is connected to the bracket 5a.
  • the movable body 5 moves together with the nut member 3 via the coupler 7.
  • the guide unit 6 supports the movable body 5 so as to be movable in an axial direction in which the screw shaft 2 extends (hereinafter, referred to as an axial direction).
  • the guide unit 6 includes a linear guide 61 and a rail 62.
  • the linear guide 61 is provided with a plurality of screw holes 61a.
  • the linear guide 61 is arrange
  • the rails 62 are arranged on both sides of the screw shaft 2 in a plan view and extend in parallel with the screw shaft 2.
  • the linear guide 61 engages with the rail 62 via a ball (rolling body) (not shown), and guides the movable body 5 along the rail 62.
  • the coupler 7 connects the nut member 3 and the movable body 5 in the axial direction via a plurality of balls 71 (second ball rolling elements).
  • the coupler 7 has rolling element arrangement grooves 72 that arrange the balls 71 in the circumferential direction of the screw shaft 2.
  • the nut member 3 is integrally provided with a plate-like flange portion 32.
  • the coupler 7 has a pair of plate members 73 a and 73 b that sandwich the flange portion 32 via the balls 71.
  • the rolling element arrangement groove 72 of the present embodiment is formed by a concave rolling element arrangement surface 33 provided in the flange portion 32 and a concave rolling element arrangement surface 74 provided in the pair of plate members 73a and 73b. .
  • At least one of the pair of plate members 73a and 73b (both in the present embodiment) has an attachment hole 75 (attachment portion) that is detachably attached to the movable body 5.
  • the attachment hole 75 penetrates the pair of plate members 73a and 73b in the axial direction.
  • the bracket 5 a of the movable body 5 has a screw hole 5 a 2 at a position facing the mounting hole 75.
  • a bolt 76 is screwed into the screw hole 5a2.
  • the bolt 76 is disposed so as to pass through the attachment hole 75 and tightens the pair of plate members 73a and 73b in the axial direction.
  • the pair of plate members 73 a and 73 b are detachably attached to the movable body 5.
  • FIG. 3 is a perspective view of the nut member 3 including the coupler 7 according to the first embodiment of the present invention.
  • FIG. 4 is a perspective view of the nut member 3 with the pair of plate members 73a and 73b removed in the first embodiment of the present invention.
  • FIG. 5 is a view of the rolling element arrangement groove 72 in the first embodiment of the present invention viewed from the axial direction.
  • FIG. 6 is an enlarged cross-sectional view of a main part of the coupler 7 in the first embodiment of the present invention.
  • the pair of plate members 73a and 73b are formed in a disc shape. At the center of the pair of plate members 73a and 73b, an opening 77 through which the screw shaft 2 is inserted is provided. An outer peripheral surface 78A of the pair of plate members 73a and 73b is formed in a circular shape. On the other hand, inner peripheral surfaces 78B (openings 77) of the pair of plate members 73a and 73b are formed in an elliptical shape.
  • the pair of plate members 73a and 73b is provided with a split surface 80 extending in the radial direction (hereinafter referred to as the radial direction) of the screw shaft 2, and each of the plate members 73a and 73b can be divided into two (see FIG. 4). ).
  • the rolling element arrangement groove 72 includes a first rolling element arrangement groove 72 a arranged on one surface side 32 ⁇ / b> A in the axial direction of the flange portion 32 and the other surface in the axial direction of the flange portion 32.
  • channel 72b arrange
  • the one surface side 32 ⁇ / b> A includes one surface 32 a in the axial direction of the flange portion 32 and one corner portion 32 b in the axial direction of the flange portion 32.
  • the other surface side 32 ⁇ / b> B includes the other surface 32 c in the axial direction of the flange portion 32 and the other corner portion 32 d in the axial direction of the flange portion 32.
  • the first rolling element arrangement groove 72a of the present embodiment is arranged at one corner portion 32b in the axial direction of the flange portion 32. Further, the second rolling element arrangement groove 72 b of this embodiment is arranged at the other corner portion 32 d in the axial direction of the flange portion 32. As shown in FIG. 5, the flange portion 32 is formed in an elliptical shape when viewed from the axial direction. For this reason, the rolling element arrangement groove 72 (the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b) is formed in an elliptical shape when viewed from the axial direction.
  • the rolling element arrangement groove 72 is formed in an elliptical shape whose center coincides with the axis C of the screw shaft 2. Moreover, the rolling element arrangement
  • the rolling element arrangement groove 72 has a line-symmetric shape with respect to the vertical axis, and also has a line-symmetric shape with respect to the horizontal axis.
  • the rolling element arrangement groove 72 of the present embodiment is formed in an elliptical shape having a major axis that is approximately 1.2 to 1.5 times the length of the minor axis.
  • the first rolling element arrangement groove 72 a and the second rolling element arrangement groove 72 b are in contact with the ball 71 with a predetermined contact angle with respect to the radial direction of the screw shaft 2.
  • the contact angle of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is set to an angular type of front combination.
  • the angular contact angle of the front combination refers to the straight line L1 connecting the contact point between the ball 71 and the rolling element arrangement surfaces 33 and 74 in the first rolling element arrangement groove 72a and the ball in the second rolling element arrangement groove 72b.
  • the straight line L2 that connects the contact points of 71 and the rolling element arrangement surfaces 33 and 74 gradually approaches the flange portion 32, and the contact angle with respect to the flange portion 32 gradually decreases.
  • the contact angle of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is ⁇
  • the following relational expression (1) is satisfied. 45 ° ⁇ ⁇ 90 °
  • the angle is larger than 45 °.
  • the contact angle ⁇ of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is set with a predetermined margin from the above critical value.
  • the following relational expression (2) is satisfied. It is preferable. 50 ° ⁇ ⁇ 85 ° (2)
  • the contact angle ⁇ of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is set to 60 °, for example.
  • the screw shaft 2 is rotated by a motor 10.
  • the screw shaft 2 rotates, the nut member 3 engaged with the screw shaft 2 through the ball 4 moves in the axial direction.
  • the bracket 5 a of the movable body 5 is connected to the nut member 3 via the connector 7.
  • the movable body 5 moves in the axial direction together with the nut member 3 while being guided in the axial direction by the guide portion 6.
  • vibration during rotation of the screw shaft 2 occurs. Occurs (schematically indicated by reference numeral F1 in FIG. 6).
  • the coupler 7 couples the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction.
  • the nut member 3 and the movable body 5 are rigidly connected in the axial direction, and the fluctuation during rotation of the screw shaft 2 in the radial direction is caused by the contact fluctuation of the ball 71 in the rolling element arrangement groove 72. Can be absorbed.
  • the coupler 7 restrains the movable body 5 in the axial direction to improve the positional accuracy, and keeps the movable body 5 in a floating state in the radial direction, and transmits the vibration during rotation of the screw shaft 2 to the movable body 5. Can not be.
  • the coupler 7 has a rolling element arrangement groove 72 for arranging a plurality of balls 71 in the circumferential direction of the screw shaft 2.
  • the rolling element arrangement groove 72 is formed in a non-circular (elliptical) shape when viewed from the axial direction. According to this configuration, the rotation of the nut member 3 can be restricted only by the restraint by the ball 71. That is, even if the screw shaft 2 rotates, the rolling element arrangement groove 72 is non-circular, so that the ball 71 cannot roll in the circumferential direction of the screw shaft 2, and as a result, the nut member 3 does not rotate. For this reason, only the ball 71 can receive the rotational torque of the nut member 3.
  • the rotation of the nut member 3 can be restricted only by the ball 71 without providing a rotation-preventing bolt as in the prior art, and the screw shaft 2 transmitted to the movable body 5 without impairing the floating function due to the contact fluctuation of the ball 71.
  • the vibration during rotation can be absorbed.
  • the rolling element disposing groove 72 has a line-symmetric shape with respect to a vertical axis extending in the vertical direction orthogonal to the axial direction, and a horizontal axis extending in the horizontal direction orthogonal to the axial direction. It is also a line symmetrical shape. According to this configuration, since the contact stress due to the plurality of balls 71 is balanced in the vertical direction and the horizontal direction, anisotropy (bias) of restraining force by the balls 71 in the vertical direction and the horizontal direction can be suppressed. it can. For this reason, it is possible to suppress the deviation of the shake during rotation of the screw shaft 2.
  • the rolling element arrangement groove 72 is elliptical when viewed from the axial direction.
  • the plurality of balls 71 can receive the rotational torque of the nut member 3 as a whole.
  • the burden of rotational torque on the ball 71 disposed at the corner of the polygon is increased.
  • the rotational torque can be applied to the entire 71 approximately evenly. For this reason, the component lifetime of the plurality of balls 71 is extended, and the maintenance frequency, replacement frequency, and the like can be reduced.
  • the coupler 7 is the flange part 32 via the some ball
  • the pair of plate members 73 a and 73 b have attachment holes 75 that are detachably attached to the movable body 5. According to this configuration, it is possible to connect to the movable body 5 while sandwiching the flange portion 32 between the plurality of balls 71 disposed in the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b. That is, the structure in which only the ball 71 is in contact with the flange portion 32 (nut member 3) can be realized by the pair of plate members 73a and 73b. The vibration during rotation can be absorbed.
  • each of the first rolling element arrangement groove 72 a and the second rolling element arrangement groove 72 b comes into contact with the ball 71 with a predetermined contact angle with respect to the radial direction of the screw shaft 2. Yes.
  • the contact angle of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is set to an angular type of front combination.
  • the pitching of the nut member 3 (schematically indicated by the symbol F2 in FIG. 6) can also be absorbed. That is, the angular combination of the front combination has a small distance between the operating points with respect to the flange portion 32, and therefore can allow the ball 71 to change the angle of the nut member 3 in the pitch direction due to contact variation. For this reason, it is possible to prevent vibration due to pitching of the nut member 3 from being transmitted to the movable body 5.
  • the contact angle ⁇ of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b satisfies the relationship of 45 ° ⁇ ⁇ 90 °. That is, when the contact angle ⁇ is larger than 45 °, the rigidity in the axial direction of the coupler 7 becomes higher than the rigidity in the radial direction, and the nut member 3 and the movable body 5 can be rigidly connected in the axial direction. The moving accuracy of the movable body 5 in the direction can be increased. Further, when the contact angle ⁇ is smaller than 90 °, the coupler 7 can be an angular type as described above, and not only the radial runout (indicated by reference numeral F1) during rotation of the screw shaft 2 but also a nut. The vibration (indicated by reference numeral F2) due to pitching of the member 3 can also be absorbed.
  • the ball screw type driving device 1 includes the screw shaft 2 having the spiral ball rolling groove 21 on the outer peripheral surface 2a and the ball rolling groove 21 on the inner peripheral surface 3b. And a nut member 3 having a spiral ball load rolling groove 31 facing each other, a plurality of balls 4 interposed between the ball rolling groove 21 and the ball load rolling groove 31, and movable together with the nut member 3 It has a movable body 5 and a guide portion 6 that supports the movable body 5 so as to be movable in the axial direction in which the screw shaft 2 extends.
  • the ball screw type driving device 1 includes a coupler 7 that connects the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction.
  • the coupler 7 has rolling element arrangement grooves 72 that arrange a plurality of balls 71 in the circumferential direction of the screw shaft 2.
  • the rolling element arrangement groove 72 is formed in a non-circular (elliptical) shape when viewed from the axial direction. With this configuration, it is possible to regulate the rotation of the nut member 3 and absorb the vibration during rotation of the screw shaft transmitted to the movable body 5.
  • FIG. 7 is a cross-sectional view of a ball screw type driving apparatus 1A according to the second embodiment of the present invention.
  • FIG. 8 is a view of the rolling element arrangement groove 72A in the second embodiment of the present invention viewed from the axial direction.
  • the ball screw type driving device 1A of the second embodiment is different from the above embodiment in that it has a movable body floating unit 100 that is detachably attached.
  • the movable body floating unit 100 has a coupler 7 that connects the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction.
  • the coupler 7 of the second embodiment includes a mounting plate 101 that is detachably attached to the movable body 5 and a pair of plate members 102 a and 102 b that sandwich the mounting plate 101 via a plurality of balls 71.
  • the rolling element arrangement groove 72A for arranging a plurality of balls 71 is formed by a concave rolling element arrangement surface 103 provided on the mounting plate 101 and a concave rolling element arrangement surface 104 provided on the pair of plate members 102a and 102b. It is formed.
  • the mounting plate 101 has a mounting hole 105 penetrating in the axial direction.
  • a counterbore 105 a is formed in the mounting hole 105.
  • a bolt 76 that is screwed into the screw hole 5 a 2 of the bracket 5 a of the movable body 5 is inserted into the mounting hole 105.
  • the attachment plate 101 is detachably attached to the movable body 5 by bolts 76.
  • the mounting plate 101 has a through hole 106 that penetrates in the axial direction. Bolts 107 that connect the pair of plate members 102 a and 102 b are inserted through the through holes 106.
  • the plate member 102 a has a through hole 108 that penetrates in the axial direction at a position facing the through hole 106.
  • a counterbore 108 a is formed in the through hole 108.
  • the plate member 102 b has a screw hole 109 at a position facing the through hole 106.
  • a bolt 107 is screwed into the screw hole 109.
  • the bolt 107 is disposed so as to pass through the through holes 106 and 108, and tightens the pair of plate members 102a and 102b in the axial direction. Thereby, a pair of board member 102a, 102b is connected.
  • the through hole 106 is formed larger than the diameter of the bolt 107 and is configured so that the bolt 107 does not contact the mounting plate 101.
  • At least one of the pair of plate members 102a and 102b (in this embodiment, the plate member 102a) has a screw hole 109 (attachment portion) that is detachably attached to the nut member 3.
  • a bolt 110 is screwed into the screw hole 109.
  • the flange part 32 of the nut member 3 is provided with an insertion hole 111 through which the bolt 110 is inserted.
  • a counterbore 111 a is formed in the insertion hole 111.
  • the bolt 110 tightens the plate member 102a and the flange portion 32 in the axial direction. Accordingly, the plate member 102a is detachably attached to the nut member 3.
  • the rolling element arrangement groove 72A is a first rolling element arrangement groove 72a arranged on one surface 101a in the axial direction of the mounting plate 101 and a second rolling element arrangement groove 72a arranged on the other surface 101b in the axial direction of the mounting plate 101.
  • Rolling element arrangement groove 72b The 1st rolling element arrangement
  • channel 72b become a structure which arrange
  • the rolling element arrangement grooves 72A (the first rolling element arrangement grooves 72a and the second rolling element arrangement grooves 72b) are formed in a polygonal shape as viewed from the axial direction, as shown in FIG.
  • the rolling element arrangement groove 72A is formed in a quadrangle whose center of gravity coincides with the axis C of the screw shaft 2. Further, the rolling element arrangement groove 72A is formed in a rectangular shape in which a short side is set along a vertical axis extending in the vertical direction and a long side is set along a horizontal axis extending in the horizontal direction. The rolling element arrangement groove 72A is formed in a rectangular shape having a long side of about 1.2 to 1.5 times the length of the short side. A predetermined curvature is given to the corner portion 72A1 that is an intersection of the short side and the long side of the rectangle, and the corner portion 72A1 is curved.
  • the coupler 7 couples the nut member 3 and the movable body 5 via the plurality of balls 71 in the axial direction as shown in FIG.
  • the nut member 3 and the movable body 5 are rigidly connected in the axial direction, and the fluctuation during rotation of the screw shaft 2 in the radial direction is caused by the contact fluctuation of the ball 71 in the rolling element arrangement groove 72. Can be absorbed. Further, as shown in FIG.
  • the coupler 7 includes a mounting plate 101 detachably attached to the movable body 5, a first rolling element arrangement groove 72 a, and a second rolling element arrangement groove. And a pair of plate members 102 a and 102 b that sandwich the attachment plate 101 via a plurality of balls 71 arranged in 72 b, and the plate member 102 a has a screw hole 109 that is detachably attached to the nut member 3.
  • the nut member 3 and the movable body 5 are detachable while the mounting plate 101 is sandwiched between the plurality of balls 71 arranged in the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b. Can be linked to. For this reason, the movable body floating unit 100 can be easily installed with respect to the existing ball screw type driving device.
  • the rolling element arrangement groove 72A of the second embodiment is arranged on one surface 101a and the other surface 101b in the axial direction of the mounting plate 101. According to this configuration, it is easy to process the rolling element arrangement groove 72A. That is, when the rolling element disposition groove 72 is disposed in the corners 32b and 32d (see FIG. 6) of the flange portion 32 as in the above-described embodiment, it is necessary to form the groove with a cam grinding machine or the like.
  • the rolling element arrangement groove 72A is formed on the plate surface of the mounting plate 101 as in the embodiment, it can be formed by a general processing machine such as a ball end mill. The groove can be easily formed.
  • the movable body floating unit 100 provided in the ball screw type driving device 1A includes the screw shaft 2 having the spiral ball rolling groove 21 on the outer peripheral surface 2a, the inner shaft A nut member 3 having a spiral ball load rolling groove 31 opposed to the ball rolling groove 21 on the peripheral surface 3b, and a plurality of balls 4 interposed between the ball rolling groove 21 and the ball load rolling groove 31. And a movable body 5 movable together with the nut member 3 and a guide portion 6 that supports the movable body 5 so as to be movable in the axial direction in which the screw shaft 2 extends.
  • the movable body floating unit 100 includes a coupler 7 that couples the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction.
  • the coupler 7 has a rolling element arrangement groove 72 ⁇ / b> A for arranging a plurality of balls 71 in the circumferential direction of the screw shaft 2.
  • the rolling element arrangement groove 72A is formed in a non-circular (rectangular) shape when viewed from the axial direction. With this configuration, it is possible to regulate the rotation of the nut member 3 and absorb the vibration during rotation of the screw shaft transmitted to the movable body 5.
  • FIG. 9 is a view of the rolling element arrangement groove 72B in another embodiment of the present invention viewed from the axial direction.
  • the rolling element arrangement groove 72B shown in FIG. 9 has a first rolling element arrangement groove 72a and a second rolling element arrangement groove 72a having a periodicity in which the same shape (wave shape) is repeated a predetermined number of times in the circumferential direction of the screw shaft 2.
  • 72b The period of the first rolling element arrangement groove 72a and the period of the second rolling element arrangement groove 72b are shifted from each other by a half period. According to this configuration, the period of the first rolling element arrangement groove 72a and the period of the second rolling element arrangement groove 72b are equal to each other than the structure of the above-described embodiment (see FIGS. 5 and 8). Anisotropy (bias) due to the restraining force of the ball 71 can be greatly reduced.
  • FIG. 10 is a view of the rolling element arrangement groove 72C in another embodiment of the present invention viewed from the axial direction.
  • the rolling element arrangement groove 72 ⁇ / b> C shown in FIG. 10 is formed in a circular shape when viewed from the axial direction, the circular center C ⁇ b> 1 does not coincide with the axial center C of the screw shaft 2.
  • the center C1 of the rolling element arrangement groove 72C is offset from the axis C of the screw shaft 2, the ball 71 cannot roll in the circumferential direction of the screw shaft 2 even if it is circular. Therefore, similarly to the above embodiment, the rotation of the nut member 3 can be restricted only by the restraint by the ball 71.
  • the rolling element arrangement grooves are arranged in one row, but the rolling element arrangement grooves are arranged in a plurality of rows, and the diameter of the second rolling element is made smaller (preferably than the first rolling element). (Small).
  • the contact stress of Hertz increases, and the rotation of the nut member 3 can be suitably controlled.
  • the ball is exemplified as the second rolling element, but the second rolling element only needs to be able to change the contact point.
  • a spherical roller having a thick center and narrow both ends is adopted. can do.
  • the rolling element arrangement groove is arranged in an angular shape, but may be arranged in a thrust type as in the second embodiment.
  • rolling element arrangement grooves are arranged on one surface and the other surface in the axial direction of the flange portion.
  • the shape of the rolling element arrangement groove of the first embodiment may be a polygon (square or other polygon) as shown in FIG. 8, or may be an irregular shape as shown in FIG. As shown in FIG. 10, it may be circular and the center may be offset.
  • the rolling element arrangement groove is arranged in a thrust type, but may be arranged in an angular type as in the second embodiment.
  • the contact angle can be changed in the second embodiment as in the first embodiment by changing the shape and arrangement of the grooves as disclosed in Japanese Patent Application Laid-Open No. 2006-600767.
  • the shape of the rolling element arrangement groove of the second embodiment may be an ellipse as shown in FIG. 5, a polygon other than the quadrangle shown in FIG. 8, or as shown in FIG.
  • the shape may be irregular, or may be circular and offset at the center as shown in FIG.
  • the rotation of the nut member can be restricted and the vibration during rotation of the screw shaft transmitted to the movable body can be absorbed.
  • Ball screw type drive device Screw shaft 2a Outer peripheral surface 3 Nut member 3b Inner peripheral surface 4 Ball (first rolling element) 5 Movable body 6 Guide part 7 Coupler 21 Ball rolling groove (Rolling body rolling groove) 31 Ball-loaded rolling groove (rolling element loaded rolling groove) 32 Flange portion 32A One side 32B The other side 71 Ball (second rolling element) 72, 72A, 72B, 72C Rolling element arrangement groove 72a First rolling element arrangement groove 72b Second rolling element arrangement groove 73a, 73b A pair of plate members 75 Attachment holes (attachment portions) DESCRIPTION OF SYMBOLS 100 Movable body floating unit 101 Mounting plate 102a, 102b A pair of plate member 105 Mounting hole (mounting part) C axis C1 center ⁇ contact angle

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Abstract

This ball-screw type drive device has a connector (7) for axially connecting a nut member (3) and a movable body through a plurality of balls (71). The connector (7) has a rolling body arrangement groove (72) in which the plurality of balls (71) are arranged in the circumferential direction of a threaded shaft (2). The rolling body arrangement groove (72) is formed either in a non-circular shape when viewed in the axial direction or in a circular shape when viewed in the axial view, the center of the circular shape not coinciding with the axis (C) of the threaded shaft (2).

Description

ボールねじ式駆動装置及び可動体フローティングユニットBall screw type driving device and movable body floating unit
　本発明は、ボールねじ式駆動装置及び可動体フローティングユニットに関する。
　本願は、２０１５年９月９日に、日本に出願された特願２０１５－１７７６１９号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a ball screw type driving device and a movable body floating unit.
This application claims priority based on Japanese Patent Application No. 2015-177619 filed in Japan on September 9, 2015, the contents of which are incorporated herein by reference.
　特許文献１には、ボールねじ式駆動装置が開示されている。このボールねじ式駆動装置は、案内部により移動自在に支持された可動体にナット部材を備える。このナット部材に螺合するねじ軸の往復回転により、該ナット部材を介して可動体を案内部に沿って往復駆動する。このボールねじ式駆動装置は、可動体に周方向に略等配に固定され且つナット部材の取り付け孔に遊嵌された取り付けボルトと、可動体とナット部材との間に介在された第１スラスト軸受と、ナット部材と取り付けボルトとの間に介在された第２スラスト軸受とにより、ナット部材を可動体に対してラジアル方向に移動自在に支持し、ねじ軸の回転時の振れを吸収する。 Patent Document 1 discloses a ball screw type driving device. This ball screw type driving device includes a nut member on a movable body supported movably by a guide portion. By reciprocating rotation of the screw shaft screwed to the nut member, the movable body is driven to reciprocate along the guide portion via the nut member. The ball screw type driving device includes a mounting bolt fixed to the movable body in a substantially equal circumferential direction and loosely fitted in a mounting hole of the nut member, and a first thrust interposed between the movable body and the nut member. The second thrust bearing interposed between the bearing and the nut member and the mounting bolt supports the nut member movably in the radial direction with respect to the movable body, and absorbs vibration during rotation of the screw shaft.
特開２０１１－２０４７号公報JP 2011-2047 A
　上記構成のボールねじ式駆動装置は、ナット部材と可動体との間にスラスト軸受がある。このため、可動体に固定された取り付けボルトをナット部材の取り付け孔に挿通し、この取り付けボルトによりナット部材の回転を規制している（特許文献１の段落００２３参照）。しかしながら、取り付けボルトによりスラスト軸受の回転を規制すると、取り付けボルトとナット部材とが拘束されるため、ねじ軸の回転時の振れが、ナット部材、取り付けボルトを介して可動体に直接伝わる。このように、上記構成では、スラスト軸受のフローティング機能が意味を成さず、ねじ軸の回転時の振れを吸収することができない可能性がある。 The ball screw type driving device having the above configuration has a thrust bearing between the nut member and the movable body. For this reason, the mounting bolt fixed to the movable body is inserted into the mounting hole of the nut member, and the rotation of the nut member is regulated by the mounting bolt (see paragraph 0023 of Patent Document 1). However, when the rotation of the thrust bearing is restricted by the mounting bolt, the mounting bolt and the nut member are constrained, so that the vibration during rotation of the screw shaft is directly transmitted to the movable body via the nut member and the mounting bolt. Thus, in the above configuration, the floating function of the thrust bearing does not make sense, and there is a possibility that vibration during rotation of the screw shaft cannot be absorbed.
　本発明は、ナット部材の回転を規制し、可動体に伝わるねじ軸の回転時の振れを吸収することができるボールねじ式駆動装置及び可動体フローティングユニットを提供する。 The present invention provides a ball screw type driving device and a movable body floating unit capable of restricting the rotation of a nut member and absorbing a vibration during rotation of a screw shaft transmitted to the movable body.
　本発明の第一の態様によれば、ボールねじ式駆動装置は、外周面に螺旋状の転動体転動溝を有するねじ軸と、内周面に前記転動体転動溝と対向する螺旋状の転動体負荷転動溝を有するナット部材と、前記転動体転動溝と前記転動体負荷転動溝との間に介在する複数の第１の転動体と、前記ナット部材と共に移動可能な可動体と、前記可動体を前記ねじ軸が延びる軸方向に移動可能に支持する案内部と、前記ナット部材と前記可動体とを前記軸方向において複数の第２の転動体を介して連結する連結器と、を備える。前記連結器は、前記複数の第２の転動体を前記ねじ軸の周方向に配置する転動体配置溝を有する。前記転動体配置溝は、前記軸方向から視て非円形、若しくは、前記軸方向から視て前記ねじ軸の軸心と中心が一致しない円形に形成されている。 According to the first aspect of the present invention, a ball screw type driving device includes a screw shaft having a spiral rolling element rolling groove on an outer peripheral surface, and a spiral shape facing the rolling element rolling groove on an inner peripheral surface. A nut member having a rolling element load rolling groove, a plurality of first rolling elements interposed between the rolling element rolling groove and the rolling element load rolling groove, and a movable movable together with the nut member A body, a guide portion that supports the movable body so as to be movable in an axial direction in which the screw shaft extends, and a connection that couples the nut member and the movable body via a plurality of second rolling elements in the axial direction. A vessel. The coupler includes a rolling element arrangement groove that arranges the plurality of second rolling elements in a circumferential direction of the screw shaft. The rolling element arrangement groove is formed in a non-circular shape when viewed from the axial direction or a circular shape whose center does not coincide with the axis of the screw shaft as viewed from the axial direction.
　本発明の第二の態様によれば、前記ナット部材には、板状のフランジ部が一体で設けられていてもよい。前記転動体配置溝は、前記フランジ部の前記軸方向における一方の面側に配置された第１の転動体配置溝と、前記フランジ部の前記軸方向における他方の面側に配置された第２の転動体配置溝と、から構成されていてもよい。前記連結器は、前記第１の転動体配置溝及び前記第２の転動体配置溝に配置された前記複数の第２の転動体を介して前記フランジ部を挟み込む一対の板部材を有し、前記一対の板部材の少なくともいずれか一方は、前記可動体に着脱自在に取り付けられる取付部を有していてもよい。 According to the second aspect of the present invention, the nut member may be integrally provided with a plate-like flange portion. The rolling element arrangement groove includes a first rolling element arrangement groove disposed on one surface side in the axial direction of the flange portion and a second surface disposed on the other surface side in the axial direction of the flange portion. And rolling element arrangement grooves. The coupler has a pair of plate members that sandwich the flange portion via the plurality of second rolling elements arranged in the first rolling element arrangement groove and the second rolling element arrangement groove, At least one of the pair of plate members may have an attachment portion that is detachably attached to the movable body.
　本発明の第三の態様によれば、前記連結器は、前記可動体に着脱自在に取り付けられる取付板を有していてもよい。前記転動体配置溝は、前記取付板の前記軸方向における一方の面に配置された第１の転動体配置溝と、前記取付板の前記軸方向における他方の面に配置された第２の転動体配置溝と、から構成されてもよい。前記連結器は、前記第１の転動体配置溝及び前記第２の転動体配置溝に配置された前記複数の第２の転動体を介して前記取付板を挟み込む一対の板部材を有し、前記一対の板部材の少なくともいずれか一方は、前記ナット部材に着脱自在に取り付けられる取付部を有してもよい。 According to the third aspect of the present invention, the coupler may have an attachment plate that is detachably attached to the movable body. The rolling element arrangement groove includes a first rolling element arrangement groove disposed on one surface of the mounting plate in the axial direction and a second rolling element disposed on the other surface of the mounting plate in the axial direction. And a moving body arranging groove. The coupler has a pair of plate members that sandwich the mounting plate via the plurality of second rolling elements arranged in the first rolling element arrangement groove and the second rolling element arrangement groove, At least one of the pair of plate members may have an attachment portion that is detachably attached to the nut member.
　本発明の第四の態様によれば、前記第１の転動体配置溝及び前記第２の転動体配置溝のそれぞれは、前記ねじ軸の半径方向に対して所定の接触角をもって前記第２の転動体と接触してもよい。前記第１の転動体配置溝及び前記第２の転動体配置溝の接触角は、正面組み合わせのアンギュラ型に設定されていてもよい。 According to a fourth aspect of the present invention, each of the first rolling element arrangement groove and the second rolling element arrangement groove has a predetermined contact angle with respect to the radial direction of the screw shaft. You may contact a rolling element. The contact angle of the first rolling element arrangement groove and the second rolling element arrangement groove may be set to a front combination angular type.
　本発明の第五の態様によれば、前記第１の転動体配置溝及び前記第２の転動体配置溝の接触角αは、
　４５°＜α＜９０°
　の関係を満たしてもよい。 According to the fifth aspect of the present invention, the contact angle α of the first rolling element arrangement groove and the second rolling element arrangement groove is:
45 ° <α <90 °
May be satisfied.
　本発明の第六の態様によれば、ボールねじ式駆動装置に設けられる可動体フローティングユニットは、外周面に螺旋状の転動体転動溝を有するねじ軸と、内周面に前記転動体転動溝と対向する螺旋状の転動体負荷転動溝を有するナット部材と、前記転動体転動溝と前記転動体負荷転動溝との間に介在する複数の第１の転動体と、前記ナット部材と共に移動可能な可動体と、前記可動体を前記ねじ軸が延びる軸方向に移動可能に支持する案内部と、前記ナット部材と前記可動体とを前記軸方向において複数の第２の転動体を介して連結する連結器とを備える。前記連結器は、前記複数の第２の転動体を前記ねじ軸の周方向に配置する転動体配置溝を有する。前記転動体配置溝は、前記軸方向から視て非円形、若しくは、前記軸方向から視て前記ねじ軸の軸心と中心が一致しない円形に形成されている。 According to the sixth aspect of the present invention, the movable body floating unit provided in the ball screw type driving device includes a screw shaft having a spiral rolling element rolling groove on the outer peripheral surface, and the rolling element rolling unit on the inner peripheral surface. A nut member having a spiral rolling element load rolling groove facing the rolling groove, a plurality of first rolling elements interposed between the rolling element rolling groove and the rolling element load rolling groove, and A movable body that can move together with the nut member, a guide portion that supports the movable body so as to be movable in an axial direction in which the screw shaft extends, and a plurality of second rollers in the axial direction. And a coupler coupled via a moving body. The coupler includes a rolling element arrangement groove that arranges the plurality of second rolling elements in a circumferential direction of the screw shaft. The rolling element arrangement groove is formed in a non-circular shape when viewed from the axial direction or a circular shape whose center does not coincide with the axis of the screw shaft as viewed from the axial direction.
　上記したボールねじ式駆動装置及び可動体フローティングユニットによれば、ナット部材の回転を規制し、可動体に伝わるねじ軸の回転時の振れを吸収することができる。 According to the ball screw type driving device and the movable body floating unit described above, the rotation of the nut member can be restricted and the vibration during rotation of the screw shaft transmitted to the movable body can be absorbed.
本発明の第１実施形態におけるボールねじ式駆動装置の平面図である。It is a top view of the ball screw type drive device in a 1st embodiment of the present invention. 本発明の図１の矢視Ａ－Ａ断面図である。FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 of the present invention. 本発明の第１実施形態における連結器を備えたナット部材の斜視図である。It is a perspective view of a nut member provided with a connector in a 1st embodiment of the present invention. 本発明の第１実施形態における一対の板部材を取り外したナット部材３の斜視図である。It is a perspective view of nut member 3 which removed a pair of board members in a 1st embodiment of the present invention. 本発明の第１実施形態における転動体配置溝を軸方向から視た図である。It is the figure which looked at the rolling element arrangement | positioning groove | channel in 1st Embodiment of this invention from the axial direction. 本発明の第１実施形態における連結器の要部拡大断面図である。It is a principal part expanded sectional view of the coupler in 1st Embodiment of this invention. 本発明の第２実施形態におけるボールねじ式駆動装置の断面図である。It is sectional drawing of the ball screw type drive device in 2nd Embodiment of this invention. 本発明の第２実施形態における転動体配置溝を軸方向から視た図である。It is the figure which looked at the rolling element arrangement | positioning groove | channel in 2nd Embodiment of this invention from the axial direction. 本発明の一別実施形態における転動体配置溝を軸方向から視た図である。It is the figure which looked at the rolling element arrangement | positioning groove | channel in another embodiment of this invention from the axial direction. 本発明の一別実施形態における転動体配置溝を軸方向から視た図である。It is the figure which looked at the rolling element arrangement | positioning groove | channel in another embodiment of this invention from the axial direction.
　以下、本発明の実施形態について図面を参照して説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　（第１実施形態）
　図１は、本発明の第１実施形態におけるボールねじ式駆動装置１の平面図である。図２は、図１の矢視Ａ－Ａ断面図である。
　図１及び図２に示すように、ボールねじ式駆動装置１は、ねじ軸２と、ナット部材３と、ボール４（第１の転動体）と、可動体５と、案内部６と、連結器７と、を有する。 (First embodiment)
FIG. 1 is a plan view of a ball screw type driving device 1 according to a first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG.
As shown in FIGS. 1 and 2, the ball screw type driving device 1 includes a screw shaft 2, a nut member 3, a ball 4 (first rolling element), a movable body 5, a guide portion 6, and a connection. And a container 7.
　ねじ軸２は、図２に示すように、外周面２ａに螺旋状のボール転動溝２１（転動体転動溝）を有する。ねじ軸２の両端は、図１に示すように、ボールねじ式駆動装置１のベース部８に対し、ベアリング９を介して回転自在に支持されている。ねじ軸２の一方の端部は、モーター１０と接続されている。モーター１０は、ベース部８に固定された支持部材１２に支持される。モーター１０は、ねじ軸２を、その軸心Ｃを中心に回転させる。 The screw shaft 2 has a spiral ball rolling groove 21 (rolling element rolling groove) on the outer peripheral surface 2a as shown in FIG. As shown in FIG. 1, both ends of the screw shaft 2 are rotatably supported via a bearing 9 with respect to the base portion 8 of the ball screw type driving device 1. One end of the screw shaft 2 is connected to the motor 10. The motor 10 is supported by a support member 12 fixed to the base portion 8. The motor 10 rotates the screw shaft 2 around its axis C.
　ナット部材３は、図２に示すように、内周面３ｂに螺旋状のボール負荷転動溝３１（転動体負荷転動溝）を有する。ボール負荷転動溝３１は、ボール転動溝２１に対向する。ボール転動溝２１とボール負荷転動溝３１が対向すると、その対向する部分にボール負荷転走路１３が形成される。ボール４は、ボール転動溝２１とボール負荷転動溝３１との間に介在する。 2, the nut member 3 has a spiral ball load rolling groove 31 (rolling element load rolling groove) on the inner peripheral surface 3b. The ball load rolling groove 31 faces the ball rolling groove 21. When the ball rolling groove 21 and the ball load rolling groove 31 face each other, the ball load rolling path 13 is formed in the facing portion. The ball 4 is interposed between the ball rolling groove 21 and the ball load rolling groove 31.
　ボール４は、ボール負荷転走路１３において負荷がかかった状態で転動する。ナット部材３は、リターンパイプ等の図示しない転動体循環部品を有する。転動体循環部品は、転動体循環路を有し、ボール負荷転走路１３の一端と他端とを接続する。ボール負荷転走路１３の一端と他端とを接続すると、ボール４の無限循環路が形成される。すなわち、ボール４は、ボール負荷転走路１３の他端（末尾）まで転動した後、転動体循環部品の中を移動して、ボール負荷転走路１３の一端（先頭）に再び導入される。 The ball 4 rolls under a load on the ball load rolling path 13. The nut member 3 has rolling element circulation parts (not shown) such as a return pipe. The rolling element circulation component has a rolling element circulation path and connects one end and the other end of the ball load rolling path 13. When one end and the other end of the ball load rolling path 13 are connected, an infinite circulation path of the ball 4 is formed. That is, the ball 4 rolls to the other end (tail) of the ball load rolling path 13, then moves in the rolling element circulation component, and is introduced again to one end (lead) of the ball load rolling path 13.
　可動体５は、図１に示すように、その中央にブラケット５ａが配置される平面視矩形状の可動テーブルである。ブラケット５ａには、複数のねじ孔５ａ１が設けられており、図示しないボルトによって可動体５のテーブル部分に固定される。図２に示すように、ブラケット５ａには、後述する連結器７が接続されている。可動体５は、連結器７を介してナット部材３と共に移動する。 As shown in FIG. 1, the movable body 5 is a movable table having a rectangular shape in a plan view in which a bracket 5a is disposed at the center thereof. The bracket 5a is provided with a plurality of screw holes 5a1, and is fixed to the table portion of the movable body 5 by bolts (not shown). As shown in FIG. 2, the coupler 7 mentioned later is connected to the bracket 5a. The movable body 5 moves together with the nut member 3 via the coupler 7.
　案内部６は、図１に示すように、可動体５をねじ軸２が延びる軸方向（以下、軸方向という）に移動可能に支持する。案内部６は、リニアガイド６１と、レール６２と、を有する。リニアガイド６１には、複数のねじ孔６１ａが設けられている。リニアガイド６１は、可動体５の四隅に配置され、ねじ孔６１ａに螺合する図示しないボルトによって可動体５に固定される。レール６２は、平面視でねじ軸２の両側に配置されると共に、ねじ軸２と平行に延びる。リニアガイド６１は、図示しないボール（転動体）を介してレール６２に係合し、可動体５をレール６２に沿って案内する。 As shown in FIG. 1, the guide unit 6 supports the movable body 5 so as to be movable in an axial direction in which the screw shaft 2 extends (hereinafter, referred to as an axial direction). The guide unit 6 includes a linear guide 61 and a rail 62. The linear guide 61 is provided with a plurality of screw holes 61a. The linear guide 61 is arrange | positioned at the four corners of the movable body 5, and is fixed to the movable body 5 with the volt | bolt which is not shown in FIG. The rails 62 are arranged on both sides of the screw shaft 2 in a plan view and extend in parallel with the screw shaft 2. The linear guide 61 engages with the rail 62 via a ball (rolling body) (not shown), and guides the movable body 5 along the rail 62.
　連結器７は、図２に示すように、ナット部材３と可動体５とを軸方向において複数のボール７１（第２のボール転動体）を介して連結する。連結器７は、ボール７１をねじ軸２の周方向に配置する転動体配置溝７２を有する。ナット部材３には、板状のフランジ部３２が一体で設けられている。連結器７は、ボール７１を介してフランジ部３２を挟み込む一対の板部材７３ａ，７３ｂを有する。本実施形態の転動体配置溝７２は、フランジ部３２に設けられた凹状の転動体配置面３３と、一対の板部材７３ａ，７３ｂに設けられた凹状の転動体配置面７４とによって形成される。 As shown in FIG. 2, the coupler 7 connects the nut member 3 and the movable body 5 in the axial direction via a plurality of balls 71 (second ball rolling elements). The coupler 7 has rolling element arrangement grooves 72 that arrange the balls 71 in the circumferential direction of the screw shaft 2. The nut member 3 is integrally provided with a plate-like flange portion 32. The coupler 7 has a pair of plate members 73 a and 73 b that sandwich the flange portion 32 via the balls 71. The rolling element arrangement groove 72 of the present embodiment is formed by a concave rolling element arrangement surface 33 provided in the flange portion 32 and a concave rolling element arrangement surface 74 provided in the pair of plate members 73a and 73b. .
　一対の板部材７３ａ，７３ｂの少なくともいずれか一方（本実施形態では両方）は、可動体５に着脱自在に取り付けられる取付孔７５（取付部）を有する。取付孔７５は、一対の板部材７３ａ，７３ｂを軸方向に貫通する。可動体５のブラケット５ａは、取付孔７５に対向する位置にねじ孔５ａ２を有する。ねじ孔５ａ２には、ボルト７６が螺合する。ボルト７６は、取付孔７５を挿通するように配置され、一対の板部材７３ａ，７３ｂを軸方向に締め付ける。これにより、一対の板部材７３ａ，７３ｂが可動体５に対し着脱自在に取り付けられる。 At least one of the pair of plate members 73a and 73b (both in the present embodiment) has an attachment hole 75 (attachment portion) that is detachably attached to the movable body 5. The attachment hole 75 penetrates the pair of plate members 73a and 73b in the axial direction. The bracket 5 a of the movable body 5 has a screw hole 5 a 2 at a position facing the mounting hole 75. A bolt 76 is screwed into the screw hole 5a2. The bolt 76 is disposed so as to pass through the attachment hole 75 and tightens the pair of plate members 73a and 73b in the axial direction. As a result, the pair of plate members 73 a and 73 b are detachably attached to the movable body 5.
　次に、図３～図６を参照して、連結器７の構成について詳しく説明する。
　図３は、本発明の第１実施形態における連結器７を備えたナット部材３の斜視図である。図４は、本発明の第１実施形態における一対の板部材７３ａ，７３ｂを取り外したナット部材３の斜視図である。図５は、本発明の第１実施形態における転動体配置溝７２を軸方向から視た図である。図６は、本発明の第１実施形態における連結器７の要部拡大断面図である。 Next, the configuration of the coupler 7 will be described in detail with reference to FIGS.
FIG. 3 is a perspective view of the nut member 3 including the coupler 7 according to the first embodiment of the present invention. FIG. 4 is a perspective view of the nut member 3 with the pair of plate members 73a and 73b removed in the first embodiment of the present invention. FIG. 5 is a view of the rolling element arrangement groove 72 in the first embodiment of the present invention viewed from the axial direction. FIG. 6 is an enlarged cross-sectional view of a main part of the coupler 7 in the first embodiment of the present invention.
　図３に示すように、一対の板部材７３ａ，７３ｂは、円板状に形成されている。一対の板部材７３ａ，７３ｂの中央には、ねじ軸２が挿通する開口７７が設けられている。一対の板部材７３ａ，７３ｂの外周面７８Ａは、円形に形成されている。一方、一対の板部材７３ａ，７３ｂの内周面７８Ｂ（開口７７）は、楕円形に形成されている。この一対の板部材７３ａ，７３ｂには、ねじ軸２の半径方向（以下、半径方向という）に延びる割面８０が設けられ、それぞれが２つに分割可能な構成となっている（図４参照）。 As shown in FIG. 3, the pair of plate members 73a and 73b are formed in a disc shape. At the center of the pair of plate members 73a and 73b, an opening 77 through which the screw shaft 2 is inserted is provided. An outer peripheral surface 78A of the pair of plate members 73a and 73b is formed in a circular shape. On the other hand, inner peripheral surfaces 78B (openings 77) of the pair of plate members 73a and 73b are formed in an elliptical shape. The pair of plate members 73a and 73b is provided with a split surface 80 extending in the radial direction (hereinafter referred to as the radial direction) of the screw shaft 2, and each of the plate members 73a and 73b can be divided into two (see FIG. 4). ).
　転動体配置溝７２は、図４に示すように、フランジ部３２の軸方向における一方の面側３２Ａに配置された第１の転動体配置溝７２ａと、フランジ部３２の軸方向における他方の面側３２Ｂに配置された第２の転動体配置溝７２ｂと、を含む。なお、一方の面側３２Ａとは、図６に示すように、フランジ部３２の軸方向における一方の面３２ａと、フランジ部３２の軸方向における一方の角部３２ｂと、を含む。また、他方の面側３２Ｂとは、フランジ部３２の軸方向における他方の面３２ｃと、フランジ部３２の軸方向における他方の角部３２ｄと、を含む。 As shown in FIG. 4, the rolling element arrangement groove 72 includes a first rolling element arrangement groove 72 a arranged on one surface side 32 </ b> A in the axial direction of the flange portion 32 and the other surface in the axial direction of the flange portion 32. 2nd rolling element arrangement | positioning groove | channel 72b arrange | positioned at the side 32B. As shown in FIG. 6, the one surface side 32 </ b> A includes one surface 32 a in the axial direction of the flange portion 32 and one corner portion 32 b in the axial direction of the flange portion 32. The other surface side 32 </ b> B includes the other surface 32 c in the axial direction of the flange portion 32 and the other corner portion 32 d in the axial direction of the flange portion 32.
　本実施形態の第１の転動体配置溝７２ａは、フランジ部３２の軸方向における一方の角部３２ｂに配置される。また、本実施形態の第２の転動体配置溝７２ｂは、フランジ部３２の軸方向における他方の角部３２ｄに配置される。フランジ部３２は、図５に示すように、軸方向から視て楕円形に形成されている。このため、転動体配置溝７２（第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂ）は、軸方向から視て楕円形に形成されている。 The first rolling element arrangement groove 72a of the present embodiment is arranged at one corner portion 32b in the axial direction of the flange portion 32. Further, the second rolling element arrangement groove 72 b of this embodiment is arranged at the other corner portion 32 d in the axial direction of the flange portion 32. As shown in FIG. 5, the flange portion 32 is formed in an elliptical shape when viewed from the axial direction. For this reason, the rolling element arrangement groove 72 (the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b) is formed in an elliptical shape when viewed from the axial direction.
　具体的に、転動体配置溝７２は、ねじ軸２の軸心Ｃに中心が一致する楕円形に形成されている。また、転動体配置溝７２は、その楕円形の長軸が上下方向に延びる鉛直軸に沿って設定され、その楕円形の短軸が水平方向に延びる水平軸に沿って設定されている。転動体配置溝７２は、鉛直軸に対して線対称形状であり、また、水平軸に対しても線対称形状である。本実施形態の転動体配置溝７２は、短軸の長さに対し、長軸が１．２～１．５倍程度の長さを有する楕円形に形成されている。 Specifically, the rolling element arrangement groove 72 is formed in an elliptical shape whose center coincides with the axis C of the screw shaft 2. Moreover, the rolling element arrangement | positioning groove | channel 72 is set along the horizontal axis | shaft in which the elliptical long axis extends in the up-down direction, and the elliptical short axis extends in the horizontal direction. The rolling element arrangement groove 72 has a line-symmetric shape with respect to the vertical axis, and also has a line-symmetric shape with respect to the horizontal axis. The rolling element arrangement groove 72 of the present embodiment is formed in an elliptical shape having a major axis that is approximately 1.2 to 1.5 times the length of the minor axis.
　図６に示すように、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂは、ねじ軸２の半径方向に対して所定の接触角をもってボール７１と接触している。第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂの接触角は、正面組み合わせのアンギュラ型に設定されている。正面組み合わせのアンギュラ型の接触角とは、第１の転動体配置溝７２ａにおいてボール７１と転動体配置面３３，７４との接触点を結ぶ直線Ｌ１と、第２の転動体配置溝７２ｂにおいてボール７１と転動体配置面３３，７４との接触点を結ぶ直線Ｌ２とが、フランジ部３２に向かって漸次近接し、フランジ部３２に対する作用点間距離が漸次小さくなる接触角をいう。 As shown in FIG. 6, the first rolling element arrangement groove 72 a and the second rolling element arrangement groove 72 b are in contact with the ball 71 with a predetermined contact angle with respect to the radial direction of the screw shaft 2. The contact angle of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is set to an angular type of front combination. The angular contact angle of the front combination refers to the straight line L1 connecting the contact point between the ball 71 and the rolling element arrangement surfaces 33 and 74 in the first rolling element arrangement groove 72a and the ball in the second rolling element arrangement groove 72b. The straight line L2 that connects the contact points of 71 and the rolling element arrangement surfaces 33 and 74 gradually approaches the flange portion 32, and the contact angle with respect to the flange portion 32 gradually decreases.
　第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂの接触角をαとしたとき、下記関係式（１）を満たす。
　４５°＜α＜９０°　…（１）
　すなわち、接触角α＝４５°は、連結器７の軸方向における剛性（拘束）が、半径方向における剛性（拘束）と同じになる臨界値であり、接触角αは、軸方向における剛性が高くなるように、４５°よりも大きい方が好ましい。また、接触角α＝９０°は、アキシャル型ではなくスラスト型となる臨界値であり、接触角αは９０°よりも小さい方が好ましい。 When the contact angle of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is α, the following relational expression (1) is satisfied.
45 ° <α <90 ° (1)
That is, the contact angle α = 45 ° is a critical value at which the rigidity (restraint) in the axial direction of the coupler 7 is the same as the rigidity (restraint) in the radial direction, and the contact angle α is high in rigidity in the axial direction. Thus, it is preferable that the angle is larger than 45 °. Further, the contact angle α = 90 ° is a critical value that is not an axial type but a thrust type, and the contact angle α is preferably smaller than 90 °.
　なお、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂの接触角αは、上記臨界値よりも所定の余裕をもって設定することが好ましく、例えば、下記関係式（２）を満たすことが好ましい。
　５０°＜α＜８５°　…（２）
　本実施形態では、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂの接触角αが、例えば、６０°に設定されている。 In addition, it is preferable to set the contact angle α of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b with a predetermined margin from the above critical value. For example, the following relational expression (2) is satisfied. It is preferable.
50 ° <α <85 ° (2)
In the present embodiment, the contact angle α of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is set to 60 °, for example.
　続いて、上記構成のボールねじ式駆動装置１の動作及び連結器７の作用について説明する。 Subsequently, the operation of the ball screw type driving device 1 configured as described above and the operation of the coupler 7 will be described.
　図１に示すように、ねじ軸２は、モーター１０によって回転する。ねじ軸２が回転すると、ボール４を介してねじ軸２に係合するナット部材３が軸方向に移動する。可動体５のブラケット５ａは、連結器７を介してナット部材３に連結されている。可動体５は、案内部６によって軸方向に案内されながら、ナット部材３と共に軸方向に移動する。このようにボールねじ式駆動装置１が動作すると、ねじ軸２、ナット部材３、ボール４の加工精度等に起因して、半径方向に振れ（以下、ねじ軸２の回転時の振れという）が発生する（図６において符号Ｆ１で模式的に示す）。 1, the screw shaft 2 is rotated by a motor 10. When the screw shaft 2 rotates, the nut member 3 engaged with the screw shaft 2 through the ball 4 moves in the axial direction. The bracket 5 a of the movable body 5 is connected to the nut member 3 via the connector 7. The movable body 5 moves in the axial direction together with the nut member 3 while being guided in the axial direction by the guide portion 6. When the ball screw type driving device 1 operates as described above, due to the processing accuracy of the screw shaft 2, nut member 3, and ball 4, vibration in the radial direction (hereinafter referred to as vibration during rotation of the screw shaft 2) occurs. Occurs (schematically indicated by reference numeral F1 in FIG. 6).
　ここで、連結器７は、ナット部材３と可動体５とを軸方向において複数のボール７１を介して連結している。この構成によれば、軸方向においてナット部材３と可動体５とを剛的に連結しつつ、半径方向においてねじ軸２の回転時の振れを転動体配置溝７２の中のボール７１の接点変動により吸収することができる。すなわち、連結器７は、軸方向においては可動体５を拘束して位置精度を高めつつ、半径方向においては可動体５をフローティング状態として、可動体５にねじ軸２の回転時の振れを伝えないようにすることができる。 Here, the coupler 7 couples the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction. According to this configuration, the nut member 3 and the movable body 5 are rigidly connected in the axial direction, and the fluctuation during rotation of the screw shaft 2 in the radial direction is caused by the contact fluctuation of the ball 71 in the rolling element arrangement groove 72. Can be absorbed. In other words, the coupler 7 restrains the movable body 5 in the axial direction to improve the positional accuracy, and keeps the movable body 5 in a floating state in the radial direction, and transmits the vibration during rotation of the screw shaft 2 to the movable body 5. Can not be.
　連結器７は、複数のボール７１をねじ軸２の周方向に配置する転動体配置溝７２を有する。転動体配置溝７２は、図５に示すように、軸方向から視て非円形（楕円形）に形成されている。この構成によれば、ボール７１による拘束のみで、ナット部材３の回転を規制できる。すなわち、ねじ軸２が回転しても、転動体配置溝７２が非円形であるため、ボール７１は、ねじ軸２の周方向に転動できず、結果、ナット部材３が回らない。このため、ボール７１のみによってナット部材３の回転トルクを受けることができる。したがって、従来のような回り止め用のボルトを設けなくとも、ボール７１のみによってナット部材３の回転を規制でき、ボール７１の接点変動によるフローティング機能を損なうことなく、可動体５に伝わるねじ軸２の回転時の振れを吸収することができる。 The coupler 7 has a rolling element arrangement groove 72 for arranging a plurality of balls 71 in the circumferential direction of the screw shaft 2. As shown in FIG. 5, the rolling element arrangement groove 72 is formed in a non-circular (elliptical) shape when viewed from the axial direction. According to this configuration, the rotation of the nut member 3 can be restricted only by the restraint by the ball 71. That is, even if the screw shaft 2 rotates, the rolling element arrangement groove 72 is non-circular, so that the ball 71 cannot roll in the circumferential direction of the screw shaft 2, and as a result, the nut member 3 does not rotate. For this reason, only the ball 71 can receive the rotational torque of the nut member 3. Accordingly, the rotation of the nut member 3 can be restricted only by the ball 71 without providing a rotation-preventing bolt as in the prior art, and the screw shaft 2 transmitted to the movable body 5 without impairing the floating function due to the contact fluctuation of the ball 71. The vibration during rotation can be absorbed.
　また、転動体配置溝７２は、図５に示すように、軸方向と直交する上下方向に延びる鉛直軸に対して線対称形状であり、且つ、軸方向と直交する水平方向に延びる水平軸に対しても線対称形状である。この構成によれば、複数のボール７１による接触応力が、上下方向と水平方向のそれぞれでバランスするため、上下方向及び水平方向におけるボール７１による拘束力の異方性（偏り）を抑制することができる。このため、ねじ軸２の回転時の振れの偏りを抑制することができる。 Further, as shown in FIG. 5, the rolling element disposing groove 72 has a line-symmetric shape with respect to a vertical axis extending in the vertical direction orthogonal to the axial direction, and a horizontal axis extending in the horizontal direction orthogonal to the axial direction. It is also a line symmetrical shape. According to this configuration, since the contact stress due to the plurality of balls 71 is balanced in the vertical direction and the horizontal direction, anisotropy (bias) of restraining force by the balls 71 in the vertical direction and the horizontal direction can be suppressed. it can. For this reason, it is possible to suppress the deviation of the shake during rotation of the screw shaft 2.
　さらに、転動体配置溝７２は、軸方向から視て楕円形である。この構成によれば、複数のボール７１が全体でナット部材３の回転トルクを受けることができる。例えば、転動体配置溝７２を多角形に形成した場合は、多角形の角部に配置されたボール７１への回転トルクの負担が大きくなるが、楕円形では角部がないため、複数のボール７１の全体に略均等に回転トルクを負担させることができる。このため、複数のボール７１の部品寿命が延び、メンテナンス頻度や交換頻度等を下げることができる。 Furthermore, the rolling element arrangement groove 72 is elliptical when viewed from the axial direction. According to this configuration, the plurality of balls 71 can receive the rotational torque of the nut member 3 as a whole. For example, when the rolling element disposition groove 72 is formed in a polygon, the burden of rotational torque on the ball 71 disposed at the corner of the polygon is increased. The rotational torque can be applied to the entire 71 approximately evenly. For this reason, the component lifetime of the plurality of balls 71 is extended, and the maintenance frequency, replacement frequency, and the like can be reduced.
　また、本実施形態では、図２に示すように、連結器７は、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂに配置された複数のボール７１を介してフランジ部３２を挟み込む一対の板部材７３ａ，７３ｂを有し、一対の板部材７３ａ，７３ｂは、可動体５に着脱自在に取り付けられる取付孔７５を有する。この構成によれば、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂに配置された複数のボール７１によってフランジ部３２を挟み込みつつ、可動体５に接続することができる。すなわち、一対の板部材７３ａ，７３ｂによって、フランジ部３２（ナット部材３）に対してボール７１のみが接触する構造を実現できるため、ボール７１の接点変動によるフローティング機能を損なうことなく、ねじ軸２の回転時の振れを吸収することができる。 Moreover, in this embodiment, as shown in FIG. 2, the coupler 7 is the flange part 32 via the some ball | bowl 71 arrange | positioned at the 1st rolling element arrangement | positioning groove | channel 72a and the 2nd rolling element arrangement | positioning groove | channel 72b. The pair of plate members 73 a and 73 b have attachment holes 75 that are detachably attached to the movable body 5. According to this configuration, it is possible to connect to the movable body 5 while sandwiching the flange portion 32 between the plurality of balls 71 disposed in the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b. That is, the structure in which only the ball 71 is in contact with the flange portion 32 (nut member 3) can be realized by the pair of plate members 73a and 73b. The vibration during rotation can be absorbed.
　さらに、図６に示すように、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂのそれぞれは、ねじ軸２の半径方向に対して所定の接触角をもってボール７１と接触している。第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂの接触角は、正面組み合わせのアンギュラ型に設定されている。この構成によれば、ナット部材３のピッチング（図６において符号Ｆ２で模式的に示す）も吸収することができる。すなわち、正面組み合わせのアンギュラ型は、フランジ部３２に対する作用点間距離が小さいため、ボール７１に接点変動によって、ナット部材３のピッチ方向の角度変化を許容することができる。このため、可動体５にナット部材３のピッチングによる振れも伝達しないようにすることができる。 Further, as shown in FIG. 6, each of the first rolling element arrangement groove 72 a and the second rolling element arrangement groove 72 b comes into contact with the ball 71 with a predetermined contact angle with respect to the radial direction of the screw shaft 2. Yes. The contact angle of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b is set to an angular type of front combination. According to this configuration, the pitching of the nut member 3 (schematically indicated by the symbol F2 in FIG. 6) can also be absorbed. That is, the angular combination of the front combination has a small distance between the operating points with respect to the flange portion 32, and therefore can allow the ball 71 to change the angle of the nut member 3 in the pitch direction due to contact variation. For this reason, it is possible to prevent vibration due to pitching of the nut member 3 from being transmitted to the movable body 5.
　また、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂの接触角αは、４５°＜α＜９０°の関係を満たす。すなわち、接触角αが４５°より大きいと、連結器７の軸方向における剛性が、半径方向における剛性よりも高くなり、ナット部材３と可動体５とを軸方向において剛的に連結でき、軸方向における可動体５の移動精度を高めることができる。また、接触角αが９０°より小さいと、連結器７を上記のようにアンギュラ型とすることができ、ねじ軸２の回転時の半径方向の振れ（符号Ｆ１で示す）だけでなく、ナット部材３のピッチングによる振れ（符号Ｆ２で示す）も吸収することができる。 Also, the contact angle α of the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b satisfies the relationship of 45 ° <α <90 °. That is, when the contact angle α is larger than 45 °, the rigidity in the axial direction of the coupler 7 becomes higher than the rigidity in the radial direction, and the nut member 3 and the movable body 5 can be rigidly connected in the axial direction. The moving accuracy of the movable body 5 in the direction can be increased. Further, when the contact angle α is smaller than 90 °, the coupler 7 can be an angular type as described above, and not only the radial runout (indicated by reference numeral F1) during rotation of the screw shaft 2 but also a nut. The vibration (indicated by reference numeral F2) due to pitching of the member 3 can also be absorbed.
　このように、上述の本実施形態によれば、ボールねじ式駆動装置１は、外周面２ａに螺旋状のボール転動溝２１を有するねじ軸２と、内周面３ｂにボール転動溝２１と対向する螺旋状のボール負荷転動溝３１を有するナット部材３と、ボール転動溝２１とボール負荷転動溝３１との間に介在する複数のボール４と、ナット部材３と共に移動可能な可動体５と、可動体５をねじ軸２が延びる軸方向に移動可能に支持する案内部６と、を有する。このボールねじ式駆動装置１は、ナット部材３と可動体５とを軸方向において複数のボール７１を介して連結する連結器７を有する。連結器７は、複数のボール７１をねじ軸２の周方向に配置する転動体配置溝７２を有する。転動体配置溝７２は、軸方向から視て非円形（楕円形）に形成されている。この構成により、ナット部材３の回転を規制し、可動体５に伝わるねじ軸の回転時の振れを吸収することができる。 Thus, according to the above-described embodiment, the ball screw type driving device 1 includes the screw shaft 2 having the spiral ball rolling groove 21 on the outer peripheral surface 2a and the ball rolling groove 21 on the inner peripheral surface 3b. And a nut member 3 having a spiral ball load rolling groove 31 facing each other, a plurality of balls 4 interposed between the ball rolling groove 21 and the ball load rolling groove 31, and movable together with the nut member 3 It has a movable body 5 and a guide portion 6 that supports the movable body 5 so as to be movable in the axial direction in which the screw shaft 2 extends. The ball screw type driving device 1 includes a coupler 7 that connects the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction. The coupler 7 has rolling element arrangement grooves 72 that arrange a plurality of balls 71 in the circumferential direction of the screw shaft 2. The rolling element arrangement groove 72 is formed in a non-circular (elliptical) shape when viewed from the axial direction. With this configuration, it is possible to regulate the rotation of the nut member 3 and absorb the vibration during rotation of the screw shaft transmitted to the movable body 5.
　（第２実施形態）
　次に、本発明の第２実施形態について説明する。以下の説明において、上述の実施形態と同一又は同等の構成については同一又は同等の符号を付し、その説明を簡略若しくは省略する。 (Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same or equivalent symbols, and the description thereof is simplified or omitted.
　図７は、本発明の第２実施形態におけるボールねじ式駆動装置１Ａの断面図である。図８は、本発明の第２実施形態における転動体配置溝７２Ａを軸方向から視た図である。
　図７に示すように、第２実施形態のボールねじ式駆動装置１Ａは、着脱自在に取り付けられる可動体フローティングユニット１００を有する点で、上記実施形態と異なる。 FIG. 7 is a cross-sectional view of a ball screw type driving apparatus 1A according to the second embodiment of the present invention. FIG. 8 is a view of the rolling element arrangement groove 72A in the second embodiment of the present invention viewed from the axial direction.
As shown in FIG. 7, the ball screw type driving device 1A of the second embodiment is different from the above embodiment in that it has a movable body floating unit 100 that is detachably attached.
　可動体フローティングユニット１００は、ナット部材３と可動体５とを軸方向において複数のボール７１を介して連結する連結器７を有する。第２実施形態の連結器７は、可動体５に着脱自在に取り付けられる取付板１０１と、取付板１０１を複数のボール７１を介して挟み込む一対の板部材１０２ａ，１０２ｂと、を有する。複数のボール７１を配置する転動体配置溝７２Ａは、取付板１０１に設けられた凹状の転動体配置面１０３と、一対の板部材１０２ａ，１０２ｂに設けられた凹状の転動体配置面１０４とによって形成される。 The movable body floating unit 100 has a coupler 7 that connects the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction. The coupler 7 of the second embodiment includes a mounting plate 101 that is detachably attached to the movable body 5 and a pair of plate members 102 a and 102 b that sandwich the mounting plate 101 via a plurality of balls 71. The rolling element arrangement groove 72A for arranging a plurality of balls 71 is formed by a concave rolling element arrangement surface 103 provided on the mounting plate 101 and a concave rolling element arrangement surface 104 provided on the pair of plate members 102a and 102b. It is formed.
　取付板１０１は、軸方向に貫通する取付孔１０５を有する。取付孔１０５には、座ぐり１０５ａが形成されている。取付孔１０５には、可動体５のブラケット５ａのねじ孔５ａ２に螺合するボルト７６が挿通される。取付板１０１は、ボルト７６によって可動体５に対し着脱自在に取り付けられる。また、取付板１０１は、軸方向に貫通する貫通孔１０６を有する。貫通孔１０６には、一対の板部材１０２ａ，１０２ｂを連結するボルト１０７が挿通される。 The mounting plate 101 has a mounting hole 105 penetrating in the axial direction. A counterbore 105 a is formed in the mounting hole 105. A bolt 76 that is screwed into the screw hole 5 a 2 of the bracket 5 a of the movable body 5 is inserted into the mounting hole 105. The attachment plate 101 is detachably attached to the movable body 5 by bolts 76. The mounting plate 101 has a through hole 106 that penetrates in the axial direction. Bolts 107 that connect the pair of plate members 102 a and 102 b are inserted through the through holes 106.
　板部材１０２ａは、貫通孔１０６と対向する位置に、軸方向に貫通する貫通孔１０８を有する。貫通孔１０８には、座ぐり１０８ａが形成されている。板部材１０２ｂは、貫通孔１０６と対向する位置に、ねじ孔１０９を有する。ねじ孔１０９には、ボルト１０７が螺合する。ボルト１０７は、貫通孔１０６，１０８を挿通するように配置され、一対の板部材１０２ａ，１０２ｂを軸方向に締め付ける。これにより、一対の板部材１０２ａ，１０２ｂが連結される。なお、貫通孔１０６は、ボルト１０７の径よりも大きく形成されており、ボルト１０７が取付板１０１に接触しないように構成されている。 The plate member 102 a has a through hole 108 that penetrates in the axial direction at a position facing the through hole 106. A counterbore 108 a is formed in the through hole 108. The plate member 102 b has a screw hole 109 at a position facing the through hole 106. A bolt 107 is screwed into the screw hole 109. The bolt 107 is disposed so as to pass through the through holes 106 and 108, and tightens the pair of plate members 102a and 102b in the axial direction. Thereby, a pair of board member 102a, 102b is connected. The through hole 106 is formed larger than the diameter of the bolt 107 and is configured so that the bolt 107 does not contact the mounting plate 101.
　一対の板部材１０２ａ，１０２ｂの少なくともいずれか一方（本実施形態では板部材１０２ａ）は、ナット部材３に着脱自在に取り付けられるねじ孔１０９（取付部）を有する。ねじ孔１０９には、ボルト１１０が螺合する。ナット部材３のフランジ部３２には、ボルト１１０が挿通される挿通孔１１１が設けられる。挿通孔１１１には、座ぐり１１１ａが形成されている。ボルト１１０は、板部材１０２ａとフランジ部３２とを軸方向に締め付ける。これにより、板部材１０２ａがナット部材３に対し着脱自在に取り付けられる。 At least one of the pair of plate members 102a and 102b (in this embodiment, the plate member 102a) has a screw hole 109 (attachment portion) that is detachably attached to the nut member 3. A bolt 110 is screwed into the screw hole 109. The flange part 32 of the nut member 3 is provided with an insertion hole 111 through which the bolt 110 is inserted. A counterbore 111 a is formed in the insertion hole 111. The bolt 110 tightens the plate member 102a and the flange portion 32 in the axial direction. Accordingly, the plate member 102a is detachably attached to the nut member 3.
　転動体配置溝７２Ａは、取付板１０１の軸方向における一方の面１０１ａに配置された第１の転動体配置溝７２ａと、取付板１０１の軸方向における他方の面１０１ｂに配置された第２の転動体配置溝７２ｂと、を含む。第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂは、上述したアンギュラ型ではなく、複数のボール７１をスラスト型に配置する構成となっている。この転動体配置溝７２Ａ（第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂ）は、図８に示すように、軸方向から視て多角形に形成されている。 The rolling element arrangement groove 72A is a first rolling element arrangement groove 72a arranged on one surface 101a in the axial direction of the mounting plate 101 and a second rolling element arrangement groove 72a arranged on the other surface 101b in the axial direction of the mounting plate 101. Rolling element arrangement groove 72b. The 1st rolling element arrangement | positioning groove | channel 72a and the 2nd rolling element arrangement | positioning groove | channel 72b become a structure which arrange | positions the several ball | bowl 71 not in the angular type mentioned above but in a thrust type. The rolling element arrangement grooves 72A (the first rolling element arrangement grooves 72a and the second rolling element arrangement grooves 72b) are formed in a polygonal shape as viewed from the axial direction, as shown in FIG.
　具体的に、転動体配置溝７２Ａは、ねじ軸２の軸心Ｃに重心位置が一致する四角形に形成されている。また、転動体配置溝７２Ａは、上下方向に延びる鉛直軸に沿って短辺が設定され、水平方向に延びる水平軸に沿って長辺が設定される長方形に形成されている。転動体配置溝７２Ａは、短辺の長さに対し、長辺が１．２～１．５倍程度の長さを有する長方形に形成されている。長方形の短辺と長辺との交点である角部７２Ａ１には、所定の曲率が付され、湾曲している。 Specifically, the rolling element arrangement groove 72A is formed in a quadrangle whose center of gravity coincides with the axis C of the screw shaft 2. Further, the rolling element arrangement groove 72A is formed in a rectangular shape in which a short side is set along a vertical axis extending in the vertical direction and a long side is set along a horizontal axis extending in the horizontal direction. The rolling element arrangement groove 72A is formed in a rectangular shape having a long side of about 1.2 to 1.5 times the length of the short side. A predetermined curvature is given to the corner portion 72A1 that is an intersection of the short side and the long side of the rectangle, and the corner portion 72A1 is curved.
　上記構成の可動体フローティングユニット１００によれば、上記実施形態と同様に、可動体５に伝わるねじ軸２の回転時の振れを吸収することができる。すなわち、連結器７は、図７に示すように、ナット部材３と可動体５とを軸方向において複数のボール７１を介して連結している。この構成によれば、軸方向においてナット部材３と可動体５とを剛的に連結しつつ、半径方向においてねじ軸２の回転時の振れを転動体配置溝７２の中のボール７１の接点変動により吸収することができる。また、図８に示すように、転動体配置溝７２Ａが非円形（四角形）であるため、ボール７１は、ねじ軸２の周方向に転動できず、ボール７１による拘束のみで、ナット部材３の回転を規制できる。したがって、ボール７１の接点変動によるフローティング機能を損なうことなく、可動体５に伝わるねじ軸２の回転時の振れを吸収することができる。 According to the movable body floating unit 100 having the above-described configuration, it is possible to absorb vibration during rotation of the screw shaft 2 transmitted to the movable body 5 as in the above embodiment. That is, the coupler 7 couples the nut member 3 and the movable body 5 via the plurality of balls 71 in the axial direction as shown in FIG. According to this configuration, the nut member 3 and the movable body 5 are rigidly connected in the axial direction, and the fluctuation during rotation of the screw shaft 2 in the radial direction is caused by the contact fluctuation of the ball 71 in the rolling element arrangement groove 72. Can be absorbed. Further, as shown in FIG. 8, since the rolling element arranging groove 72 </ b> A is non-circular (rectangular), the ball 71 cannot roll in the circumferential direction of the screw shaft 2, and the nut member 3 is only restrained by the ball 71. Can be controlled. Therefore, it is possible to absorb the vibration during rotation of the screw shaft 2 transmitted to the movable body 5 without impairing the floating function due to the contact variation of the ball 71.
　また、第２実施形態では、図７に示すように、連結器７は、可動体５に着脱自在に取り付けられる取付板１０１と、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂに配置された複数のボール７１を介して取付板１０１を挟み込む一対の板部材１０２ａ，１０２ｂと、を有し、板部材１０２ａは、ナット部材３に着脱自在に取り付けられるねじ孔１０９を有する。この構成によれば、第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂに配置された複数のボール７１によって取付板１０１を挟み込みつつ、ナット部材３と可動体５とを着脱自在に連結することができる。このため、既存のボールねじ式駆動装置に対し、可動体フローティングユニット１００の設置を簡単に行うことができる。 In the second embodiment, as shown in FIG. 7, the coupler 7 includes a mounting plate 101 detachably attached to the movable body 5, a first rolling element arrangement groove 72 a, and a second rolling element arrangement groove. And a pair of plate members 102 a and 102 b that sandwich the attachment plate 101 via a plurality of balls 71 arranged in 72 b, and the plate member 102 a has a screw hole 109 that is detachably attached to the nut member 3. According to this configuration, the nut member 3 and the movable body 5 are detachable while the mounting plate 101 is sandwiched between the plurality of balls 71 arranged in the first rolling element arrangement groove 72a and the second rolling element arrangement groove 72b. Can be linked to. For this reason, the movable body floating unit 100 can be easily installed with respect to the existing ball screw type driving device.
　また、第２実施形態の転動体配置溝７２Ａは、取付板１０１の軸方向における一方の面１０１ａと他方の面１０１ｂに配置される。この構成によれば、転動体配置溝７２Ａの加工が容易になる。すなわち、上述した実施形態のようにフランジ部３２の角部３２ｂ，３２ｄ（図６参照）に転動体配置溝７２を配置する場合、カム研削機械等で溝を形成する必要があるが、第２実施形態のように、取付板１０１の板面に対して転動体配置溝７２Ａを形成する場合は、ボールエンドミル等の一般的な加工機械で形成が可能であるため、図８に示すような四角形の溝を容易に形成することができる。 Further, the rolling element arrangement groove 72A of the second embodiment is arranged on one surface 101a and the other surface 101b in the axial direction of the mounting plate 101. According to this configuration, it is easy to process the rolling element arrangement groove 72A. That is, when the rolling element disposition groove 72 is disposed in the corners 32b and 32d (see FIG. 6) of the flange portion 32 as in the above-described embodiment, it is necessary to form the groove with a cam grinding machine or the like. When the rolling element arrangement groove 72A is formed on the plate surface of the mounting plate 101 as in the embodiment, it can be formed by a general processing machine such as a ball end mill. The groove can be easily formed.
　このように、上述の第２実施形態によれば、ボールねじ式駆動装置１Ａに設けられる可動体フローティングユニット１００は、外周面２ａに螺旋状のボール転動溝２１を有するねじ軸２と、内周面３ｂにボール転動溝２１と対向する螺旋状のボール負荷転動溝３１を有するナット部材３と、ボール転動溝２１とボール負荷転動溝３１との間に介在する複数のボール４と、ナット部材３と共に移動可能な可動体５と、可動体５をねじ軸２が延びる軸方向に移動可能に支持する案内部６と、を有する。この可動体フローティングユニット１００は、ナット部材３と可動体５とを軸方向において複数のボール７１を介して連結する連結器７を有する。連結器７は、複数のボール７１をねじ軸２の周方向に配置する転動体配置溝７２Ａを有する。転動体配置溝７２Ａは、軸方向から視て非円形（四角形）に形成されている。この構成により、ナット部材３の回転を規制し、可動体５に伝わるねじ軸の回転時の振れを吸収することができる。 As described above, according to the above-described second embodiment, the movable body floating unit 100 provided in the ball screw type driving device 1A includes the screw shaft 2 having the spiral ball rolling groove 21 on the outer peripheral surface 2a, the inner shaft A nut member 3 having a spiral ball load rolling groove 31 opposed to the ball rolling groove 21 on the peripheral surface 3b, and a plurality of balls 4 interposed between the ball rolling groove 21 and the ball load rolling groove 31. And a movable body 5 movable together with the nut member 3 and a guide portion 6 that supports the movable body 5 so as to be movable in the axial direction in which the screw shaft 2 extends. The movable body floating unit 100 includes a coupler 7 that couples the nut member 3 and the movable body 5 via a plurality of balls 71 in the axial direction. The coupler 7 has a rolling element arrangement groove 72 </ b> A for arranging a plurality of balls 71 in the circumferential direction of the screw shaft 2. The rolling element arrangement groove 72A is formed in a non-circular (rectangular) shape when viewed from the axial direction. With this configuration, it is possible to regulate the rotation of the nut member 3 and absorb the vibration during rotation of the screw shaft transmitted to the movable body 5.
　以上、図面を参照しながら本発明の好適な実施形態について説明したが、本発明は上記実施形態に限定されるものではない。上述した実施形態において示した各構成部材の諸形状や組み合わせ等は一例であって、本発明の主旨から逸脱しない範囲において設計要求等に基づき種々変更可能である。 The preferred embodiment of the present invention has been described above with reference to the drawings, but the present invention is not limited to the above embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
　図９は、本発明の一別実施形態における転動体配置溝７２Ｂを軸方向から視た図である。
　図９に示す転動体配置溝７２Ｂは、ねじ軸２の周方向において同一の形状（波形状）が所定回数繰り返される周期性を有する第１の転動体配置溝７２ａ及び第２の転動体配置溝７２ｂを含む。第１の転動体配置溝７２ａの周期と、第２の転動体配置溝７２ｂの周期は、互いに半周期ずれている。この構成によれば、第１の転動体配置溝７２ａの周期と、第２の転動体配置溝７２ｂの周期が、互いに一致する上述した実施形態の構造（図５、図８参照）よりも、ボール７１の拘束力による異方性（偏り）を大幅に低減することができる。 FIG. 9 is a view of the rolling element arrangement groove 72B in another embodiment of the present invention viewed from the axial direction.
The rolling element arrangement groove 72B shown in FIG. 9 has a first rolling element arrangement groove 72a and a second rolling element arrangement groove 72a having a periodicity in which the same shape (wave shape) is repeated a predetermined number of times in the circumferential direction of the screw shaft 2. 72b. The period of the first rolling element arrangement groove 72a and the period of the second rolling element arrangement groove 72b are shifted from each other by a half period. According to this configuration, the period of the first rolling element arrangement groove 72a and the period of the second rolling element arrangement groove 72b are equal to each other than the structure of the above-described embodiment (see FIGS. 5 and 8). Anisotropy (bias) due to the restraining force of the ball 71 can be greatly reduced.
　図１０は、本発明の一別実施形態における転動体配置溝７２Ｃを軸方向から視た図である。
　図１０に示す転動体配置溝７２Ｃは、軸方向から視て円形に形成されているが、円形の中心Ｃ１が、ねじ軸２の軸心Ｃに一致しない。このように、転動体配置溝７２Ｃの中心Ｃ１が、ねじ軸２の軸心Ｃからオフセットされると、円形であっても、ボール７１は、ねじ軸２の周方向に転動できない。したがって、上記実施形態と同様に、ボール７１による拘束のみで、ナット部材３の回転を規制できる。 FIG. 10 is a view of the rolling element arrangement groove 72C in another embodiment of the present invention viewed from the axial direction.
Although the rolling element arrangement groove 72 </ b> C shown in FIG. 10 is formed in a circular shape when viewed from the axial direction, the circular center C <b> 1 does not coincide with the axial center C of the screw shaft 2. Thus, if the center C1 of the rolling element arrangement groove 72C is offset from the axis C of the screw shaft 2, the ball 71 cannot roll in the circumferential direction of the screw shaft 2 even if it is circular. Therefore, similarly to the above embodiment, the rotation of the nut member 3 can be restricted only by the restraint by the ball 71.
　また、例えば、上記実施形態では、転動体配置溝を１列としたが、転動体配置溝を複数列とし、また、第２の転動体の径を小さく（好ましくは第１の転動体よりも小さく）してもよい。第２の転動体の数が増え、第２の転動体の径が小さくなると、ヘルツの接触応力が大きくなり、ナット部材３の回転を好適に規制できる。 Further, for example, in the above embodiment, the rolling element arrangement grooves are arranged in one row, but the rolling element arrangement grooves are arranged in a plurality of rows, and the diameter of the second rolling element is made smaller (preferably than the first rolling element). (Small). When the number of second rolling elements increases and the diameter of the second rolling element decreases, the contact stress of Hertz increases, and the rotation of the nut member 3 can be suitably controlled.
　また、例えば、上記実施形態では、第２の転動体としてボールを例示したが、第２の転動体としては接点変動できるものであればよく、例えば、中心が太く両端が細い球面コロ等を採用することができる。 Further, for example, in the above embodiment, the ball is exemplified as the second rolling element, but the second rolling element only needs to be able to change the contact point. For example, a spherical roller having a thick center and narrow both ends is adopted. can do.
　また、例えば、第１実施形態では、転動体配置溝をアンギュラ型に配置したが、第２実施形態のようにスラスト型に配置してもよい。この場合、フランジ部の軸方向における一方の面と他方の面にそれぞれ転動体配置溝が配置される。また、第１実施形態の転動体配置溝の形状を、図８に示すように多角形（四角形や、その他の多角形）にしてもよいし、図９に示すように異形にしてもよいし、図１０に示すように円形であって中心をオフセットさせてもよい。 Also, for example, in the first embodiment, the rolling element arrangement groove is arranged in an angular shape, but may be arranged in a thrust type as in the second embodiment. In this case, rolling element arrangement grooves are arranged on one surface and the other surface in the axial direction of the flange portion. Further, the shape of the rolling element arrangement groove of the first embodiment may be a polygon (square or other polygon) as shown in FIG. 8, or may be an irregular shape as shown in FIG. As shown in FIG. 10, it may be circular and the center may be offset.
　また、例えば、第２実施形態では、転動体配置溝をスラスト型に配置したが、第２実施形態のようにアンギュラ型に配置してもよい。例えば、公知技術である特開２００６－２００６７７号公報のように溝の形状と配置を変更することで、第２実施形態でも第１実施形態のように接触角は変更可能である。また、第２実施形態の転動体配置溝の形状を、図５に示すように楕円形にしてもよいし、図８に示す四角形以外の多角形にしてもよいし、図９に示すように異形にしてもよいし、図１０に示すように円形であって中心をオフセットさせてもよい。 Also, for example, in the second embodiment, the rolling element arrangement groove is arranged in a thrust type, but may be arranged in an angular type as in the second embodiment. For example, the contact angle can be changed in the second embodiment as in the first embodiment by changing the shape and arrangement of the grooves as disclosed in Japanese Patent Application Laid-Open No. 2006-600767. Further, the shape of the rolling element arrangement groove of the second embodiment may be an ellipse as shown in FIG. 5, a polygon other than the quadrangle shown in FIG. 8, or as shown in FIG. The shape may be irregular, or may be circular and offset at the center as shown in FIG.
　上記したボールねじ式駆動装置及び可動体フローティングユニットによれば、ナット部材の回転を規制し、可動体に伝わるねじ軸の回転時の振れを吸収することができる。 According to the ball screw type driving device and the movable body floating unit described above, the rotation of the nut member can be restricted and the vibration during rotation of the screw shaft transmitted to the movable body can be absorbed.
　１，１Ａ　　ボールねじ式駆動装置
　２　　ねじ軸
　２ａ　　外周面
　３　　ナット部材
　３ｂ　　内周面
　４　　ボール（第１の転動体）
　５　　可動体
　６　　案内部
　７　　連結器
　２１　　ボール転動溝（転動体転動溝）
　３１　　ボール負荷転動溝（転動体負荷転動溝）
　３２　　フランジ部
　３２Ａ　　一方の面側
　３２Ｂ　　他方の面側
　７１　　ボール（第２の転動体）
　７２，７２Ａ，７２Ｂ，７２Ｃ　　転動体配置溝
　７２ａ　　第１の転動体配置溝
　７２ｂ　　第２の転動体配置溝
　７３ａ，７３ｂ　　一対の板部材
　７５　　取付孔（取付部）
　１００　　可動体フローティングユニット
　１０１　　取付板
　１０２ａ，１０２ｂ　　一対の板部材
　１０５　　取付孔（取付部）
　Ｃ　　軸心
　Ｃ１　　中心
　α　　接触角 1, 1A Ball screw type drive device 2 Screw shaft 2a Outer peripheral surface 3 Nut member 3b Inner peripheral surface 4 Ball (first rolling element)
5 Movable body 6 Guide part 7 Coupler 21 Ball rolling groove (Rolling body rolling groove)
31 Ball-loaded rolling groove (rolling element loaded rolling groove)
32 Flange portion 32A One side 32B The other side 71 Ball (second rolling element)
72, 72A, 72B, 72C Rolling element arrangement groove 72a First rolling element arrangement groove 72b Second rolling element arrangement groove 73a, 73b A pair of plate members 75 Attachment holes (attachment portions)
DESCRIPTION OF SYMBOLS 100 Movable body floating unit 101 Mounting plate 102a, 102b A pair of plate member 105 Mounting hole (mounting part)
C axis C1 center α contact angle

Claims (6)

  1. 　外周面に螺旋状の転動体転動溝を有するねじ軸と、
    　内周面に前記転動体転動溝と対向する螺旋状の転動体負荷転動溝を有するナット部材と、
    　前記転動体転動溝と前記転動体負荷転動溝との間に介在する複数の第１の転動体と、
    　前記ナット部材と共に移動可能な可動体と、
    　前記可動体を前記ねじ軸が延びる軸方向に移動可能に支持する案内部と、
    　前記ナット部材と前記可動体とを前記軸方向において複数の第２の転動体を介して連結する連結器と、
    　を備え、
    　前記連結器は、前記複数の第２の転動体を前記ねじ軸の周方向に配置する転動体配置溝を有し、
    　前記転動体配置溝は、前記軸方向から視て非円形、若しくは、前記軸方向から視て前記ねじ軸の軸心と中心が一致しない円形に形成されている
    　ボールねじ式駆動装置。     A screw shaft having a spiral rolling element rolling groove on the outer peripheral surface;
    A nut member having a spiral rolling element load rolling groove facing the rolling element rolling groove on the inner peripheral surface;
    A plurality of first rolling elements interposed between the rolling element rolling grooves and the rolling element load rolling grooves;
    A movable body movable together with the nut member;
    A guide portion that supports the movable body so as to be movable in an axial direction in which the screw shaft extends;
    A coupler for connecting the nut member and the movable body in the axial direction via a plurality of second rolling elements;
    With
    The coupler includes a rolling element arrangement groove that arranges the plurality of second rolling elements in a circumferential direction of the screw shaft,
    The rolling element arrangement groove is a ball screw type driving device formed in a non-circular shape when viewed from the axial direction or a circular shape whose center does not coincide with the axis of the screw shaft when viewed from the axial direction.
  2. 　前記ナット部材には、板状のフランジ部が一体で設けられており、
    　前記転動体配置溝は、前記フランジ部の前記軸方向における一方の面側に配置された第１の転動体配置溝と、前記フランジ部の前記軸方向における他方の面側に配置された第２の転動体配置溝と、から構成され、
    　前記連結器は、前記第１の転動体配置溝及び前記第２の転動体配置溝に配置された前記複数の第２の転動体を介して前記フランジ部を挟み込む一対の板部材を有し、
    　前記一対の板部材の少なくともいずれか一方は、前記可動体に着脱自在に取り付けられる取付部を有する
    　請求項１に記載のボールねじ式駆動装置。     The nut member is integrally provided with a plate-like flange portion,
    The rolling element arrangement groove includes a first rolling element arrangement groove disposed on one surface side in the axial direction of the flange portion and a second surface disposed on the other surface side in the axial direction of the flange portion. Rolling element arrangement groove, and
    The coupler has a pair of plate members that sandwich the flange portion via the plurality of second rolling elements arranged in the first rolling element arrangement groove and the second rolling element arrangement groove,
    The ball screw type drive device according to claim 1, wherein at least one of the pair of plate members has an attachment portion that is detachably attached to the movable body.
  3. 　前記連結器は、前記可動体に着脱自在に取り付けられる取付板を有し、
    　前記転動体配置溝は、前記取付板の前記軸方向における一方の面に配置された第１の転動体配置溝と、前記取付板の前記軸方向における他方の面に配置された第２の転動体配置溝と、から構成され、
    　前記連結器は、前記第１の転動体配置溝及び前記第２の転動体配置溝に配置された前記複数の第２の転動体を介して前記取付板を挟み込む一対の板部材を有し、
    　前記一対の板部材の少なくともいずれか一方は、前記ナット部材に着脱自在に取り付けられる取付部を有する
    　請求項１に記載のボールねじ式駆動装置。     The coupler has an attachment plate that is detachably attached to the movable body,
    The rolling element arrangement groove includes a first rolling element arrangement groove disposed on one surface of the mounting plate in the axial direction and a second rolling element disposed on the other surface of the mounting plate in the axial direction. A moving body arranging groove, and
    The coupler has a pair of plate members that sandwich the mounting plate via the plurality of second rolling elements arranged in the first rolling element arrangement groove and the second rolling element arrangement groove,
    The ball screw type drive device according to claim 1, wherein at least one of the pair of plate members has an attachment portion that is detachably attached to the nut member.
  4. 　前記第１の転動体配置溝及び前記第２の転動体配置溝のそれぞれは、前記ねじ軸の半径方向に対して所定の接触角をもって前記第２の転動体と接触しており、
    　前記第１の転動体配置溝及び前記第２の転動体配置溝の接触角は、正面組み合わせのアンギュラ型に設定されている
    　請求項２または３に記載のボールねじ式駆動装置。     Each of the first rolling element arrangement groove and the second rolling element arrangement groove is in contact with the second rolling element with a predetermined contact angle with respect to the radial direction of the screw shaft,
    4. The ball screw type driving device according to claim 2, wherein a contact angle between the first rolling element arrangement groove and the second rolling element arrangement groove is set to an angular type of front combination. 5.
  5. 　前記第１の転動体配置溝及び前記第２の転動体配置溝の接触角αは、
    　４５°＜α＜９０°
    　の関係を満たす
    　請求項４に記載のボールねじ式駆動装置。     The contact angle α of the first rolling element arrangement groove and the second rolling element arrangement groove is:
    45 ° <α <90 °
    The ball screw type driving device according to claim 4, wherein the relationship is satisfied.
  6. 　ボールねじ式駆動装置に設けられる可動体フローティングユニットであって、
    　外周面に螺旋状の転動体転動溝を有するねじ軸と、
    　内周面に前記転動体転動溝と対向する螺旋状の転動体負荷転動溝を有するナット部材と、
    　前記転動体転動溝と前記転動体負荷転動溝との間に介在する複数の第１の転動体と、
    　前記ナット部材と共に移動可能な可動体と、
    　前記可動体を前記ねじ軸が延びる軸方向に移動可能に支持する案内部と、
    　前記ナット部材と前記可動体とを前記軸方向において複数の第２の転動体を介して連結する連結器と、
    　を備え、
    　前記連結器は、前記複数の第２の転動体を前記ねじ軸の周方向に配置する転動体配置溝を有し、
    　前記転動体配置溝は、前記軸方向から視て非円形、若しくは、前記軸方向から視て前記ねじ軸の軸心と中心が一致しない円形に形成されている
    　可動体フローティングユニット。     A movable body floating unit provided in a ball screw type driving device,
    A screw shaft having a spiral rolling element rolling groove on the outer peripheral surface;
    A nut member having a spiral rolling element load rolling groove facing the rolling element rolling groove on the inner peripheral surface;
    A plurality of first rolling elements interposed between the rolling element rolling grooves and the rolling element load rolling grooves;
    A movable body movable together with the nut member;
    A guide portion that supports the movable body so as to be movable in an axial direction in which the screw shaft extends;
    A coupler for connecting the nut member and the movable body in the axial direction via a plurality of second rolling elements;
    With
    The coupler includes a rolling element arrangement groove that arranges the plurality of second rolling elements in a circumferential direction of the screw shaft,
    The rolling element arrangement groove is formed in a non-circular shape when viewed from the axial direction or a circular shape whose center does not coincide with the center of the screw shaft when viewed from the axial direction.
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JP7339500B2 (en) 2019-03-25 2023-09-06 株式会社今仙電機製作所 seat slide device

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58109757A (en) * 1981-12-24 1983-06-30 Hiroshi Teramachi Ball screw with support bearing
JPH03277820A (en) * 1990-03-23 1991-12-09 T H K Kk Ball screw device using oldham's coupling
JP2016017535A (en) * 2014-07-04 2016-02-01 本田技研工業株式会社 Suspension device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58109757A (en) * 1981-12-24 1983-06-30 Hiroshi Teramachi Ball screw with support bearing
JPH03277820A (en) * 1990-03-23 1991-12-09 T H K Kk Ball screw device using oldham's coupling
JP2016017535A (en) * 2014-07-04 2016-02-01 本田技研工業株式会社 Suspension device

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JP2017053431A (en) 2017-03-16
TW201723349A (en) 2017-07-01
JP6558163B2 (en) 2019-08-14

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