JP2008051197A - Shaft coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve stability of coupling operation and durability in a shaft coupling adapted to transmit power between two parallel shafts through a cylindrical rolling element arranged in an intersecting position of guide grooves perpendicular to each other. <P>SOLUTION: A slider 9 to be engaged with a retainer 4 with a shaft (cylindrical rolling element) 3 being inserted thereto includes a recessed part 12 including a groove extending along an oblong hole 7 of the retainer 4 and a plurality of grooves perpendicular thereto. A shaft member 14 with a rolling bearing 13 fitted to the outer circumference is fixed on the inside of each recessed part 12 in parallel to the lateral direction of the oblong hole 7 of the retainer 4, and an outer ring of the rolling bearing 13 is rolled in contact with a side surface of the retainer 4. According to this, the resistance of the slider 9 in relative movement to the retainer 4 can be stabilized and minimized to stabilize the coupling operation and to reduce breakage or early wear of parts. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shaft coupling that couples two parallel shafts and transmits power between the two shafts.

  A shaft joint that connects two shafts of a general mechanical device and transmits power from the drive side to the driven side has a different structure depending on the positional relationship between the two shafts to be connected. And those that are parallel to each other (and not concentric).

As a shaft coupling for connecting two parallel shafts, the present applicant proposes a method for transmitting power via rolling elements arranged at the intersections of guide grooves orthogonal to each other between the two parallel shafts. (See Patent Document 1).
JP 2005-172217 A

  5 and 6 show an example of the above-described shaft coupling (see Japanese Patent Application No. 2005-154090 (FIGS. 5 and 6)). In this axial joint, a plurality of guide grooves 53 and 54 are provided on two rotating members 51 and 52 facing each other in the axial direction so as to be orthogonal to the guide groove on the other side. (Moving body) 55 is arranged, both end portions thereof are guided by the respective guide grooves 53, 54, and the central portion is passed through the elongated hole 57 of the retainer 56 and held. 5 and FIG. 6 show the state in which both the rotating members 51 and 52 are concentric for the sake of explanation, but they are usually used in a state in which the rotational axes of both are shifted (eccentric).

  The shafts 55 are in rolling contact with the recesses 53a and 54a of the guide grooves 53 and 54 via rolling bearings 58 fitted on the outer circumferences of both ends. Further, the central portion of the shaft 55 is passed through sliders 59 on both sides of the cage 56, and a rolling bearing 61 that rolls in the long hole 57 of the cage 56 is fitted on the outer periphery of the column member 60 that couples both the sliders 59. Thus, the shaft 55 is in a state in which the cage 56 is restrained from moving in the radial direction of the rotating member. In this state, the shaft 55 is pushed by the driving-side rotating member 51, thereby pushing the driven-side rotating member 52 while rolling inside the guide grooves 53, 54 and the long hole 57 of the cage 56, thereby generating power. introduce.

  Here, the slider 59 includes the axis of the shaft 55 by engaging with the retainer 56 in a state where the shaft 55 that receives forces having different operating points and directions from the rotating members 51 and 52 and the retainer 56 is passed. By restricting the rotation in the plane, the trouble that the shaft 55 is inclined with respect to the axial direction of the rotating member and bites into the guide grooves 53 and 54 is prevented.

  By the way, in this shaft coupling, a concave portion 62 extending in parallel with the elongated hole 57 of the cage 56 is provided on the surface of each slider 59 facing the cage 56, and a linear motion bearing 63 that is in rolling contact with the cage 56 in the concave portion 62. The slider 59 moves smoothly relative to the retainer 56 together with the shaft 55. Here, the concave portion 62 of the slider 59 is formed longer than the linear motion bearing 63 by the amount of joint eccentricity so that the roller of the linear motion bearing 63 rolls without slipping. Since it is not positioned by, there is a possibility of deviating from an appropriate position. When the displacement of the linear motion bearing 63 occurs, the slider 59 attempts to move relative to the other end side of the concave portion 62 in a state where the linear motion bearing 63 is close to one end in the longitudinal direction of the concave portion 62. In addition, the roller of the linear motion bearing 63 cannot roll, and the movement resistance of the slider 59 increases to deteriorate the operating characteristics of the joint, or the linear motion bearing 63 may be damaged due to excessive force. is there.

  On the other hand, a recess extending in parallel with the slot is provided at the edge of the slot on both sides of the cage, and a slider is fitted into the recess via a slide bearing (guide rail) to slide the slider and the slide bearing. If contact is made (see Japanese Patent Application No. 2005-154090 (FIGS. 1 and 2)), the above-mentioned problem of the linear motion bearing is eliminated, but the resistance when the slider moves relative to the cage is reduced. Furthermore, it becomes larger and the operating characteristics of the joint are likely to deteriorate. Further, when the relative movement of the slider and the cage is performed at a high speed while the surface pressure between the slider and the slide bearing is high, the slider and the slide bearing may be prematurely worn or damaged.

  An object of the present invention is to improve the stability and durability of joint operation in a shaft joint that transmits power via a cylindrical rolling element disposed at the intersection of guide grooves that are orthogonal to each other between two parallel shafts. It is to plan.

  In order to solve the above-described problems, the present invention provides a plurality of linearly extending guides on opposing surfaces of two rotating members that are axially opposed and are held in a state where the rotation axes are parallel to each other and not concentric. A cylindrical shape is provided in which a groove is provided so as to be orthogonal to a guide groove at a corresponding position of the counterpart rotating member, and the guide grooves of both the rotating members intersect with each other, and both ends are guided by the guide grooves to roll. A rolling element is provided, and a retainer for restraining movement of each rolling element in the radial direction of the rotating member through a central portion of each rolling element is provided in a linear long hole having a predetermined angle with each guide groove, Power is transmitted between the rotating members via the rolling elements, and the rolling elements are engaged with the cage while passing through the through holes between the rotating members and the cage. A shaft coupling provided with a slider that restrains rotation in a plane including the axis of the rolling element. In the state where the shaft member in which the rolling bearing is fitted on the outer periphery is oriented in parallel with the width direction of the long hole of the cage, inside the recess provided on one of the opposing surfaces of the slider and the cage Fixed, the outer ring of the rolling bearing was brought into rolling contact with the facing surface of the slider or cage facing the recess.

  That is, the resistance when the slider moves relative to the cage is provided between the slider and the cage by providing a rolling bearing fitted into a shaft member fixed to one of the members and in rolling contact with the other member. Is made stable and the joint operation is stabilized, and the parts between the two members are not easily damaged or prematurely worn.

  In the above configuration, on the facing surface of the slider or cage where the outer ring of the rolling bearing is in rolling contact, a groove that extends in parallel with the long hole of the cage and into which a part of the outer ring of the rolling bearing fits is provided. The straightness when the slider moves relative to the cage is improved, and the joint operation can be further stabilized.

  As described above, the shaft coupling according to the present invention is provided with the rolling bearing fixed to one member of the slider and the cage so as to make rolling contact with the other member. Compared with the one provided with a bearing, the resistance when the slider moves relative to the cage can be stably reduced, and the joint operation can be stabilized. In addition, the rolling bearing is unlikely to be damaged by receiving excessive force like a linear motion bearing, and even if the slider and the cage are moved at high speed, they are unlikely to be worn or damaged early like a sliding bearing. Therefore, it is advantageous in terms of durability.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4. As shown in FIGS. 1 and 2, the shaft coupling is a plate (rotating member) 1 that is fixed to each of the input / output shafts A and B that are opposed to each other in the axial direction and are held in parallel with each other. 2, a plurality of shafts (cylindrical rolling elements) 3 disposed between the plates 1 and 2, and a cage 4 that restrains the movement of each shaft 3 in the plate radial direction. Power is transmitted between the plates 1 and 2. 1 and 2 show the state where the input / output shafts A and B are concentric for the sake of explanation, but the rotation shafts of the input / output shafts A and B are usually shifted (eccentric) as will be described later. Used in state.

  Each of the plates 1 and 2 is a donut-shaped disk, fitted into the outer periphery of the shaft end portions of the input shaft A and the output shaft B, and fixed in a state of being opposed in the axial direction. Each of the plates 1 and 2 is provided with a plurality of guide grooves 5 and 6 at equal intervals in the circumferential direction so as to be orthogonal to the corresponding guide grooves of the counterpart plate. The shaft 3 is incorporated in parallel with the plate axis direction.

  Each of the guide grooves 5 and 6 is formed so as to extend linearly, and concave portions 5a and 6a having a certain depth are provided on the inner surface thereof, and both end portions of the shaft 3 are formed by the concave portions 5a and 6a. Is to guide you. In addition, each guide groove does not necessarily need to penetrate a plate like this embodiment, and should just be provided in the opposing surface of both plates.

  The retainer 4 is formed in an annular shape, and a plurality of elongated holes 7 extending linearly in a direction forming 45 degrees with the guide grooves 5 and 6 are provided at equal intervals in the circumferential direction. And is held through the central portion of the shaft 3.

  The shafts 3 are in rolling contact with the recesses 5a and 6a of the guide grooves 5 and 6 via rolling bearings 8 fitted on the outer circumferences of both ends. Further, the central portion of the shaft 3 is passed through through holes 9 a of sliders 9 provided on both sides of the cage 4, and the long holes 7 of the cage 4 are formed on the outer periphery of the two column members 10 connecting the sliders 9. Rolling bearings 11 that roll inside are fitted, and the shaft 3 is in a state in which movement in the plate radial direction is restrained by the cage 4.

  Each of the sliders 9 is a rectangular plate-like member, and has two grooves 12 extending along the long holes 7 of the cage 4 and a plurality of recesses 12 perpendicular to the grooves on the surface facing the cage 4. A shaft member 14 fitted with a rolling bearing 13 on the outer periphery thereof is fixed inside the recess 12 in a state parallel to the width direction of the long hole 7 of the cage 4, and the outer ring of the rolling bearing 13 is provided. Is in rolling contact with the side surface of the cage 4. As a result, rotation in a plane including the axis of the shaft 3 is restricted, and the slider 9 and the shaft 3 can smoothly move relative to the cage 4.

  Next, the power transmission mechanism of this shaft coupling will be described. When the input shaft A of the shaft coupling is driven to rotate and the plate 1 fixed thereto rotates, the shaft 3 pushed from the circumferential direction into the guide groove 5 of the input side plate 1 is moved by the retainer 4 to the plate diameter. Power is transmitted to the output shaft B by pushing the guide groove 6 of the plate 2 fixed to the output shaft B and rotating the output side plate 2 in a state where the movement of the direction is constrained. Even if the rotation direction of the input shaft A changes or the driving side and the driven side of the input / output shafts A and B are reversed, power transmission is performed by the same mechanism.

  At this time, each shaft 3 generates a moment of rotation because the acting point and direction of the force received from the plates 1 and 2 are not coaxial, but the shaft 9 is engaged by the engagement between the slider 9 passing the shaft 3 and the cage 4. Therefore, it is possible to maintain a posture parallel to the plate axis direction, and there is no possibility of biting into the guide grooves 5 and 6.

  The power transmission mechanism is basically the same even in a normal use state where the input / output shafts A and B are eccentric. That is, although illustration is omitted, when the input / output shafts A and B are decentered, the intersecting position of the guide grooves 5 and 6 changes in the circumferential direction of the plate, and each shaft 3 has a long hole in the guide grooves 5 and 6 and the cage 4. The power is transmitted between the plates 1 and 2 while moving inside 7.

  At this time, each slider 9 also moves relative to the cage 4 together with the shaft 3 in the direction in which the long hole 7 extends, but the outer ring of the rolling bearing 13 provided on the surface of the slider 9 facing the cage 4 rolls. Therefore, the slider 9 can smoothly move relative to each other.

  This shaft coupling has the above-described configuration, and is provided with a linear bearing or a plain bearing between the slider and the cage by providing a rolling bearing 13 that is fixed to the slider 9 and is in rolling contact with the cage 4. In comparison, since the resistance when the slider 9 moves relative to the cage 4 is stably reduced, the joint operation is excellent in stability. Further, the rolling bearing 13 is not likely to be damaged by receiving an excessive force like a linear motion bearing, and early wear and damage unlike a sliding bearing are less likely to occur, which is advantageous in terms of durability.

  Here, as shown in FIGS. 3 (a) and 3 (b), rolling bearings that extend in parallel to the long holes 7 on the opposing surfaces (both side surfaces) of the cage 4 to the sliders 9 and are fixed to the sliders 9. If the groove 15 into which a part of the outer ring 13 is fitted is provided, the straightness when the slider 9 moves relative to the cage 4 is improved, and the joint operation can be further stabilized. In this example, the outer peripheral surface of the outer ring of the bearing 13 and the bottom surface of the groove 15 that is in rolling contact with the outer surface are spherical surfaces, thereby reducing the surface pressure acting between them.

  In the above-described embodiment, the rolling bearing 13 that is in rolling contact with the cage 4 is provided on the slider 9 side. However, as shown in FIG. 4, the position at which the rolling bearing 13 is provided can be changed to the cage 4 side. . That is, in the example of FIG. 4, recesses 12 similar to those of the example of FIGS. 1 to 3 are provided on both side surfaces of the cage 4, and the shaft member 14 in which the rolling bearing 13 is fitted inside these recesses 12 is fixed. Thus, the outer ring of the rolling bearing 13 is in rolling contact with the inner surface of the slider 9. In this example, the recesses 12 on both side surfaces of the cage 4 are communicated to facilitate processing.

Partially cutaway side view of the shaft coupling of the embodiment II-II sectional view of FIG. a is a partially cutaway side view of an example in which a rolling bearing guide groove is provided in the cage, and b is a cross-sectional view illustrating the shape of the rolling bearing and the groove of a. Sectional view corresponding to FIG. 2 of the example which changed arrangement | positioning of a rolling bearing Partially cutaway side view of a conventional shaft coupling Sectional view taken along line VI-VI in FIG.

Explanation of symbols

1, 2 Plate (Rotating member)
3 Shaft (cylindrical rolling element)
4 Cage 5, 6 Guide groove 7 Long hole 8 Rolling bearing 9 Slider 9 a Through hole 10 Column member 11 Rolling bearing 12 Recess 13 Rolling bearing 14 Shaft member 15 Groove A Input shaft B Output shaft

Claims (2)

  A plurality of linearly extending guide grooves are formed on the opposing surfaces of the two rotating members that are axially opposed and are held in a state where the rotation axes are parallel to each other and not concentric. Cylindrical rolling elements that roll while being guided by both ends of each guide groove are provided at positions where the guide grooves of the two rotating members intersect with each other. A retainer is provided in a linear long hole that forms an angle of through the central portion of each rolling element to restrain the movement of each rolling element in the radial direction of the rotating member, and between the two rotating members via each rolling element. Power is transmitted, and between the rotating members and the cage, the rolling elements are engaged with the cage in a state of passing through the through-holes and rotate in a plane including the axis of the rolling elements. In a shaft coupling provided with a slider for restraining, the slider and the cage are opposed to each other. A shaft member fitted with a rolling bearing on its outer periphery is fixed inside the recess provided in any one of them in a state of being parallel to the width direction of the long hole of the cage, and the outer ring of the rolling bearing is A shaft coupling characterized by being brought into rolling contact with an opposing surface of a slider or a cage facing the recess.   The groove which extends in parallel with the long hole of the cage and into which a part of the outer ring of the rolling bearing fits is provided on the opposing surface of the slider or cage to which the outer ring of the rolling bearing comes into rolling contact. The shaft coupling according to 1.

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