JP2007162811A - Shaft coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft coupling for transmitting power between two parallel shafts via rolling elements arranged at intersecting positions of guide grooves perpendicular to each other, with a rotary member and a cage having reduced manufacturing cost. <P>SOLUTION: Plates 1, 2 as rotary members having guide grooves 5, 6 on mutually opposed faces for guiding steel balls (the rolling elements), and the cage 4 having an oblong hole 7 for storing the steel balls 3 are molded with general pressing work for a cold rolled steel plate. This reduces the number of processes for these members during work, reduces material loss and reduces manufacturing cost. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shaft coupling that couples two parallel shafts to transmit 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).

  Of these, an Oldham coupling is well known as a shaft coupling for connecting two parallel axes. However, when the Oldham coupling transmits a large amount of power, poor lubrication may occur on the friction surface between the sliders interposed between the two shafts, and the power transmission may not be performed smoothly, and a large amount of eccentricity (2 There is also a problem that the amount of deviation of the shaft in the radial direction cannot be allowed.

In addition to Oldham couplings, a plate is inserted between two axially opposed rotating members (disks), and linear motion guides are provided at a plurality of locations on the front and back surfaces of the plate, and their operating directions are orthogonal to each other on the front and back surfaces of the plate. A mechanism has been proposed in which power is transmitted between both rotating members via a plate and a linear motion guide (see Patent Document 1).
JP 2003-260902 A

  By adopting this mechanism, the required amount of eccentricity can be obtained simply by changing the length of the linear guide, and a large amount of power can be obtained by arranging a plurality of steel balls on the relative movement surface in the linear guide. It can also be transmitted smoothly. However, since a large number of linear motion guides are used, the manufacturing cost is considerably increased, it is difficult to assemble the linear motion guides with high accuracy, and the assembling work becomes very troublesome.

Therefore, prior to the present invention, the applicant of the present invention has proposed a shaft coupling that transmits power via rolling elements arranged at intersecting positions of guide grooves orthogonal to each other between two parallel axes (Patent Document 2). reference.).
JP 2005-172217 A

  This shaft coupling is provided at the intersecting position of the guide grooves of both rotating members by providing a plurality of guide grooves so as to be orthogonal to the opposing guide grooves on the opposing surfaces of the two rotating members facing each other in the axial direction. The rolling element is pushed by the driving-side rotating member in a state where movement of the rotating member in the radial direction is constrained by the cage, and transmits power by pushing the driven-side rotating member while rolling in the guide groove. It is a thing. Therefore, the frictional resistance during power transmission is small, large power can be transmitted, and the necessary amount of eccentricity can be obtained by simply changing the length of the guide groove. In addition, since the parts between the rotating members are only the rolling elements and the cage, it has many features such as low manufacturing cost and good assemblability compared to the case of using the linear guide.

  However, if the rotating member and the cage are formed by cutting, the number of steps increases and material loss is not a little, so there is room for cost reduction in these aspects.

  An object of the present invention is to reduce the manufacturing cost of a rotating member and a cage in a shaft coupling of a system that transmits power via rolling elements arranged at intersecting positions of guide grooves orthogonal to each other between two parallel axes. It is.

  In order to solve the above problems, in the present invention, the rotating member and the cage are formed by pressing a steel plate. Thereby, while reducing the processing process of a rotation member or a holder | retainer, material loss can be reduced and reduction of manufacturing cost can be aimed at.

  Here, when the rotating member is formed by pressing a steel plate, after forming each rotating member separately from the power transmission shaft, the power transmission shaft is screwed, welded, friction welded, or riveted. It is desirable to fasten by means.

  On the other hand, when the cage is formed by pressing a steel plate and the rolling element is a sphere, the cage is divided into a pair of cage pieces each having a long hole at a position corresponding to each rolling element. It is possible to suppress the axial movement of the cage and stabilize the operation of the shaft joint by joining the container pieces so that they contact the rolling elements at the surfaces formed by bending the edges of the respective long holes. it can. Alternatively, the cage comes into contact with the rolling element on the surface formed by bending the edge of the long hole at a position corresponding to each rolling element, and the bending direction of the edge of the long hole is the outer circumferential side and the inner circumferential side of the cage. In the opposite directions and alternately in the circumferential direction of the cage, the axial component force of the force by which the cage is uniformly pushed to the inner circumference side or the outer circumference side by each rolling element is obtained. By canceling out, the axial movement of the cage can be suppressed, and the operation of the shaft coupling can be stabilized.

  Also, for both the rotating member and the cage, by pressing the steel plate that is the raw material and then subjecting it to surface hardening treatment, premature wear and damage of the contact portion with the rolling element are less likely to occur. The durability of the shaft coupling can be improved.

  In the present invention, as described above, since the rotating member and the cage of the shaft coupling are formed by pressing the steel plate, the number of steps during the processing of these members can be reduced and the material loss can be reduced. This can reduce the cost of the shaft coupling. In addition, since the thickness of the rotating member and the cage can be made uniform by applying the present invention, it is possible to reduce the excess waste and reduce the weight of the shaft coupling. Further, when the shaft coupling is damaged or reaches the end of its life, it is only necessary to replace an inexpensive rotating member or cage, so that the maintenance cost can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 shows a first embodiment. As shown in FIGS. 1 (a) and 1 (b), this shaft coupling is opposed to the input / output shafts (power transmission shafts) A and B that face each other in the axial direction and whose rotating shafts are held parallel to each other. Plates 1 and 2 as rotating members fastened to respective shaft ends, steel balls 3 as a plurality of rolling elements arranged between both plates 1 and 2, and movement of each steel ball 3 in the plate radial direction , And a power transmission between the plates 1 and 2 via each steel ball 3. FIG. 1 shows the state where the input / output shafts A and B are concentric for the sake of explanation, but normally, the input / output shafts A and B are used in a state where the rotation shafts are shifted (eccentric) as described later. Is done.

  Each of the plates 1 and 2 is a disk-shaped member formed by pressing a steel plate, and is screwed to the shaft end portions of the input shaft A and the output shaft B at the four central portions, and is opposed in the axial direction. It is fixed in the state. The fastening means of the plates 1 and 2 with the input shaft A and the output shaft B is screwed so that the plates 1 and 2 can be easily replaced during maintenance, but welding, friction welding, riveting, etc. May be adopted. Four guide grooves 5 and 6 are respectively provided on the opposing surfaces of the plates 1 and 2 at equal intervals in the circumferential direction, orthogonal to the guide grooves at the corresponding positions of the counterpart plate, and 45 degrees from the plate radial direction. Extrusion is performed by a press so as to extend linearly in the direction of forming. The cage 4 is an annular shape formed by pressing a steel plate, and elongated holes 7 extending linearly in a direction perpendicular to the radial direction are provided at four locations at equal intervals in the circumferential direction. . And each said steel ball 3 is distribute | arranged to the crossing position of the guide grooves 5 and 6 of both plates 1 and 2, respectively, and is accommodated in the long hole 7 of the holder | retainer 4, and the movement of a plate radial direction is restrained. The guide grooves 5 and 6 are guided to roll.

  Here, each of the plates 1 and 2 and the cage 4 uses a general cold-rolled steel plate as a raw material, and presses the steel plate of each raw material and then performs heat treatment such as carburizing and quenching or nitriding. Thus, the surface hardness is increased so that the contact portion with the steel ball 3 is less likely to cause early wear or damage. Instead of performing such heat treatment, surface hardening treatment such as shot peening may be performed.

  This shaft coupling has the above-described configuration. When the input shaft A is driven to rotate and the plate 1 fixed thereto rotates, the steel ball 3 pushed from the circumferential direction into the guide groove 5 of the input side plate 1. However, in a state where the movement in the plate radial direction is restricted by the cage 4, 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. Is done. 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.

  The power transmission mechanism is basically the same in a normal use state in which the rotation axes of the input / output shafts A and B are shifted. That is, although illustration is omitted, when the rotation axes of the plates 1 and 2 are shifted, the crossing position of the guide grooves 5 and 6 changes in the circumferential direction of the plate, and the steel balls 3 are moved to the guide grooves 5 and 6 and the cage 4. Power is transmitted between the plates 1 and 2 while rolling in the long hole 7.

  In this shaft coupling, as described above, since the plates 1 and 2 and the cage 4 are formed by pressing a steel plate, the number of processes and material loss during processing of these members are small, and the manufacturing cost is reduced. However, since the thickness of these members is made uniform, the overall weight is reduced. Further, when the shaft coupling is damaged or reaches the end of its life, these inexpensive members can be replaced, so that maintenance can be performed easily and at low cost.

  2 and 3 show the second and third embodiments, respectively. In these embodiments, only the cage 4 is formed by pressing a steel plate, and the rotating members 8 and 9 on the input side and the output side can respectively transmit larger power than in the first embodiment. The parts corresponding to the plates 1 and 2 and the input / output shafts A and B in FIG. 1 are integrally formed by cutting a steel material. Since other basic configurations and mechanisms of power transmission are the same as those in the first embodiment, differences from the first embodiment will be described below.

  The cage 4 of the second embodiment shown in FIGS. 2 (a) and 2 (b) has a pair of cage pieces 10 and 11 having long holes 7 at positions corresponding to the steel balls 3, respectively. It is joined so that the surface 12 formed by bending the edge of the long hole 7 is in contact with the steel ball 3, and both the cage pieces 10 and 11 are formed by pressing a steel plate. In addition, it is good to perform joining of both the cage pieces 10 and 11 by electrical resistance welding, riveting, etc. so that sufficient joint strength may be obtained.

  In this embodiment, as described above, the cage 4 is in contact with the steel ball 3 at the surface 12 of the edge of the long hole 7 of both the cage pieces 10 and 11, so that the cage is compared with the first embodiment. 4 is suppressed, and the power transmission operation can be stabilized.

  On the other hand, the cage 4 of the third embodiment shown in FIGS. 3 (a) and 3 (b) is formed by pressing a single steel plate, and is long at a position corresponding to each steel ball 3. It has a hole 7 and is in contact with the steel ball 3 at a surface 12 formed by bending the edge of the long hole 7. And the bending direction of the edge part of each long hole 7 is mutually reversed in the cage | basket 4 outer peripheral side and an inner peripheral side, and is alternately changed in the cage | basket 4 circumferential direction. This is because when the power is transmitted, the output-side rotating member 9 is rotated while the steel ball 3 pushed by the input-side rotating member 8 is constrained by the cage 4. Since it is pushed to the inner peripheral side or the outer peripheral side (the direction of the force is determined by the rotation direction of the rotating member), if the bending direction of the edge of the long hole 7 is constant, the axis of the force that the cage 4 receives from the steel ball 3 This is because the directional component force moves in the axial direction.

  That is, in this shaft coupling, the cage 4 moves in the axial direction by canceling the axial component of the force that the cage 4 is uniformly pushed to the inner circumferential side or the outer circumferential side by each steel ball 3 during power transmission. This can be suppressed, and the operation of the shaft coupling can be stabilized.

Side view of the shaft coupling of the first embodiment Sectional drawing along the II line | wire of Fig.1 (a) Side view of shaft coupling of second embodiment Sectional drawing along the II-II line of Fig.2 (a) Side view of shaft coupling of third embodiment Sectional drawing along the III-III line of Fig.3 (a)

Explanation of symbols

1, 2 Plate (Rotating member)
3 Steel balls (rolling elements)
4 Cage 5, 6 Guide groove 7 Slot 8, 9 Rotating member 10, 11 Cage piece 12 Surface A Input shaft B Output shaft

Claims (6)

  A plurality of guide grooves are orthogonal to the guide grooves at corresponding positions of the counterpart rotating member 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. A rolling element that rolls while being guided by each guide groove at a position where the guide grooves of the two rotating members intersect with each other, and that holds the rolling members in the radial direction of the rotating member. In the shaft coupling in which a power is transmitted between the rotating members via the rolling elements, the rotating members are formed by pressing a steel plate. Shaft coupling.   2. The shaft according to claim 1, wherein each rotating member is fastened to a power transmission shaft separate from the rotating member by any one of screwing, welding, friction welding, or riveting. Fittings.   A plurality of guide grooves are orthogonal to the guide grooves at corresponding positions of the counterpart rotating member 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. A rolling element that rolls while being guided by each guide groove at a position where the guide grooves of the two rotating members intersect with each other, and that holds the rolling members in the radial direction of the rotating member. A shaft coupling provided with a cage and configured to transmit power between the rotating members via the rolling elements, wherein the cage is formed by pressing a steel plate. Fittings.   The rolling element is a sphere, and the retainer is composed of a pair of retainer pieces having long holes at positions corresponding to the respective rolling elements, and both the retainer pieces are bent at the edges of the long holes. The shaft coupling according to claim 3, wherein the shaft joint is joined so as to come into contact with the rolling elements on a formed surface.   The rolling element is a sphere, and the retainer has a long hole at a position corresponding to each rolling element, and contacts the rolling element at a surface formed by bending an edge of the long hole. The bending direction of the edge of the long hole of the cage is opposite to each other on the outer circumferential side and the inner circumferential side of the cage, and is alternately switched in the circumferential direction of the cage. 3. The shaft coupling according to 3.   The shaft joint according to any one of claims 1 to 5, wherein the steel sheet is subjected to a surface hardening treatment after press working.

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