JP2007003001A - Shaft coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability and durability while securing operation performance in the shaft coupling which transmits power through a rolling body arranged to an intersection location of the guide groove which crosses mutually between two shafts in parallel. <P>SOLUTION: Plates 1, 2 attached to the input-output shafts A, B consist of the plate bodies 1a, 2a and groove members 1b, 2b having the guide grooves 5, 6 and a retainer 4 which binds the radial movement of a plates for a steel ball 3 as a rolling body consists of a retainer body 4a and a hole member 4b having a long hole 7 to store the steel ball 3. These groove members 1b, 2b and hole member 4b are formed of the surface-hardened metal, and the plates 1, 2 and the retainer 4 are made in high dimension accuracy and the surface damage and the early abrasion are hard to happen on the contact part with the steel ball 3 by fixing them to the plate bodies 1a, 2a and the retainer body 4a after finish processing. <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

  Fig.5 (a) and FIG.5 (b) show an example of the shaft coupling of the system mentioned above. This shaft coupling is provided with a plurality of guide grooves 53 and 54 on the opposing surfaces of 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, and is transferred to each guide groove crossing position. The moving body 55 is arranged, and each rolling element 55 is accommodated in the long hole 57 of the cage 56. The guide grooves 53 and 54 extend linearly in a direction that forms 45 degrees with the radial direction of the rotating member. Each of the 56 long holes 57 is formed so as to extend in a direction of 45 degrees with the guide grooves 53 and 54 at the corresponding positions. FIG. 5 shows a state in which both the rotating members 51 and 52 are concentric for the sake of explanation, but normally, they are used in a state in which the rotational axes of both are shifted (eccentric).

  Each rolling element 55 is pushed by the drive-side rotating member 51 in a state where movement of the rotating member in the radial direction is restrained by the cage 56, whereby the guide grooves 53 and 54 and the long holes 57 of the cage 56 are formed. Power is transmitted by pushing the rotation member 52 on the driven side while rolling inside. Therefore, the frictional resistance at the time of power transmission is small, large power can be transmitted, and a necessary amount of eccentricity can be obtained only by changing the lengths of the guide grooves 53 and 54 and the long hole 57 of the cage 56. Further, since the parts between the rotating members 51 and 52 are only the rolling elements 55 and the retainer 56, the manufacturing cost is low and the assembling property is good.

  In addition, when the rolling element is a sphere as in the example of FIG. 5, a force acts to separate the two rotating members from each other in proportion to the transmission power. For example, as described in Patent Document 2 above, If an axial restraint mechanism is provided that sandwiches both rotating members between two restraining members arranged on the opposite side of the rotating member and restrains the change in the axial distance, the axial backlash during power transmission It is also possible to suppress the sticking.

  By the way, when it is going to transmit a big motive power with this type of shaft coupling, the contact portion with each rotating member or the rolling element of the cage, or the contact portion with the restraining member of the axial restraining mechanism of each rotating member. Therefore, in order to improve the reliability and durability of the shaft coupling, the rotating member and cage are made of high carbon steel or carburized steel, and the surface is hardened by heat treatment to prevent surface damage or damage. It is desirable to prevent premature wear.

  However, when the hardness of the rotating member or the cage is increased by the method as described above, the larger the size of the shaft coupling, the larger the deformation of the entire member during the heat treatment, and the deformation of the rotating member. The dimensional accuracy of the guide groove and the long hole of the cage decreases, and the movement of the rolling element worsens, and the frictional force between the rotating member and the restraining member increases, which deteriorates the operability of the shaft coupling. There are things to do.

  To deal with this, it may be possible to finish the guide groove, long hole, sliding surface with the restraining member, etc. after heat-treating the rotating member or cage. Since it is necessary to set the cost to be considerably large according to the size of the deformation caused by the heat treatment, processing is very laborious, and material costs and processing costs are greatly increased.

  In addition, when the size of the shaft coupling is relatively large, if the rotating member and the cage are made of steel having a large specific gravity, not only the weight of the entire shaft coupling increases, but also the sliding when the eccentric amount of both rotating members changes. The inertial force of the rotating member and the cage that are to be increased increases, and the relative sliding of the rotating members and the cage is not performed smoothly. In particular, when the amount of eccentricity changes at a high frequency, deterioration in operability due to a decrease in follow-up performance with respect to eccentric motion tends to be a problem.

  An object of the present invention is to provide reliability and durability while ensuring operability in a shaft coupling that transmits power via rolling elements arranged at intersecting positions of guide grooves perpendicular to each other between two parallel axes. It is to be able to improve.

  In order to solve the above-described problems, the present invention provides a contact portion of each rotating member with a rolling element or a restraining member, and a contact portion with a rolling element of a cage. Member). As a result, only the contact part of the rotating member and cage is processed with high hardness and processed with high accuracy, and can be assembled to the main body member, and the surface is secured while ensuring the dimensional accuracy in the assembled state of the rotating member and cage. Damage and premature wear can be made difficult to occur.

  In said structure, the hardness of the contact part of a rotating member or a holder | retainer can be performed by forming the said another member with the hard metal or the metal which performed the hardening process on the surface. At this time, if the surface hardening treatment of the separate member is to be induction-quenched in oil, the separate member after the treatment will have a surface with almost no scale and less deformation, and scale removal processing And can be used by being assembled to the main body member without finishing.

  Further, by forming the main body member from a material that is lighter than another member, the weight of the entire shaft joint can be reduced, and the rotating member or cage that slides when the eccentric amount of both rotating members changes can be reduced. The inertial force is reduced, and the followability to the eccentric motion can be improved.

  If the separate member is fixed to the main body member by any one of screwing, riveting, caulking, press-fitting, casting, insert molding, and adhesion, the rotating member and the cage can be easily assembled. This makes it easier to manufacture the shaft coupling.

  Here, if the fitting part for positioning another member is provided in the said main body member, another member can be fixed to a main body member accurately, and the improvement of the dimensional accuracy of a rotating member or a holder | retainer can be aimed at.

  Moreover, if it finishes in the state which fixed the said another member to the main body member, the dimensional accuracy of a rotating member or a holder | retainer can further be improved.

  As described above, according to the present invention, the contact portions of the rotating members of the shaft coupling with the rolling elements and the restraining members and the contact portions of the cage with the rolling elements are separated from the respective body members (separately). Therefore, only the contact portion of the rotating member or the cage can be made hard and processed with high accuracy, and then assembled to the main body member. Therefore, the shaft joint to which the present invention is applied has high dimensional accuracy of the rotating member and the cage, ensures good operability, and the rotating member and the cage are less likely to cause surface damage and early wear. It can be excellent in durability.

  And when another member is made of metal, by adopting induction hardening in oil as the surface hardening treatment, the treated another member has almost no scale on the surface and little deformation. Therefore, scale removal processing and finishing processing can be omitted, and processing costs can be greatly reduced. In addition, since a uniform hardened layer can be formed on the surface of another member, surface damage and early wear can be made more difficult to occur.

  Also, by forming the main body member with a material that is lighter than another member, the overall weight of the shaft coupling can be reduced, and the followability to eccentric motion can be improved to obtain better operability. Can do.

  Furthermore, even if damage or wear occurs in the contact part of the rotating member or cage, it is only necessary to replace another member that forms the contact part. When replacing the entire rotating member or the entire cage as in the past Compared to, the replacement work is easy and the cost is reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3 show a first embodiment. As shown in FIGS. 1 (a), 1 (b), and 2, this shaft coupling has the same diameter input / output 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 fitted to the respective shaft end portions, 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 formed of doughnut-shaped plate bodies 1a and 2a as main body members, and plate-like groove members 1b and 2b as separate members having guide grooves 5 and 6 on one side surface. In addition, the cylindrical portions provided on the inner circumferences of the plate bodies 1a and 2a are fitted into the shaft end portions of the input shaft A and the output shaft B, and are fixed so as to face each other in the axial direction.

  Each of the groove members 1b, 2b has six guide grooves 5, 6 so that the guide grooves 5, 6 are opposed to and orthogonal to the guide grooves of the groove members at corresponding positions of the counterpart plate. Screwed to concave fitting portions 1c, 2c provided at equal intervals in the direction.

  The cage 4 is formed by an annular cage body 4 a as a body member and a hole member 4 b as a separate member having a long hole 7 for housing the steel ball 3. The hole member 4b has a peripheral edge of the fitting hole 4c as six fitting portions provided at equal intervals in the circumferential direction of the cage body 4a so that the long hole 7 extends in a direction orthogonal to the radial direction of the cage. It is fixed by caulking.

  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.

  Next, the material of each member of this shaft coupling will be described. The groove members 1b and 2b of each plate 1 and 2 that come into contact with the steel ball 3 and the hole member 4b of the cage 4 are formed of a metal such as high carbon steel or carburized steel whose surface is hardened by heat treatment, It is assembled in a finished state by carbide milling or jig grinding. Moreover, the steel ball 3 which is a rolling element is also formed with the metal by which the surface was hardened. On the other hand, the plate main bodies 1a, 2a and the cage main body 4a are formed of a lighter material than the groove members 1b, 2b and the hole member 4b, such as light metals such as aluminum and synthetic resins, in order to reduce the weight of the entire shaft joint. ing.

  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 even in a normal use state in which the rotation axes of the input / output shafts A and B are deviated as shown in FIGS. 3 (a) and 3 (b). In the state of FIG. 3, the crossing position of the guide grooves 5, 6 is changed in the circumferential direction of the plate due to the shift of the rotation axis of each of the plates 1, 2, and each steel ball 3 is moved to the guide grooves 5, 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, the contact portions of the plates 1 and 2 and the steel balls 3 of the cage 4 that receive a large pressure during the power transmission are respectively the main body members (plate main bodies 1a and 2a and the cage main body 4a). Since it is formed of separate high hardness separate members (groove members 1b, 2b and hole member 4b), surface damage and early wear are unlikely to occur, and the reliability and durability are excellent. In addition, since the fitting member for positioning the separate member is provided on the main body member, and the separate member that is individually finished is fixed to these fitting portions, the dimensions of the plates 1 and 2 and the cage 4 are determined. High accuracy and good operability can be obtained. Another member, which is smaller in size than the main body member, is less deformed by heat treatment and requires less machining allowance for finishing processing. Therefore, processing can be performed relatively easily, and material costs and processing costs can be kept low. It is done.

  In addition, since the main body members of the plates 1 and 2 and the cage 4 are formed of a material that is lighter than another member, the entire shaft coupling is compared with the case where the plates and the cage are integrally formed of steel or the like having a large specific gravity. Light and easy to handle, and because the inertial force of the sliding plate and cage 4 when the eccentric amount of both plates 1 and 2 changes, the followability to eccentric motion is good, and this also works The improvement of the property is aimed at.

  FIG. 4A and FIG. 4B show a second embodiment. In this embodiment, three axial direction restraining mechanisms 8 for restraining changes in the axial distance between the two plates 1 and 2 of the shaft coupling are provided. 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.

  Each of the axial direction restraint mechanisms 8 is formed integrally with two restraint plates (constraint members) 8a and 8b disposed on the opposite side of the opposing surfaces of the plates 1 and 2, and an output side restraint plate 8b. Each of the plates 1 and 2, the cage 4 and the input side restraint plate 8a, and a screw 8c that is coupled to the screw 8c to connect the restraint plates 8a and 8b. By tightening, both the plates 1 and 2 are sandwiched between the restraining plates 8a and 8b on both sides. In addition, since this axial direction restraint mechanism 8 was provided at equal intervals in the plate circumferential direction, the guide grooves 5 and 6 of each plate 1 and 2, the long hole 7 of the cage 4 and the steel ball 3 are connected to each restraint mechanism. Two are arranged between the eight, and six sets as a whole are provided symmetrically in the circumferential direction.

  On the other hand, each of the plates 1 and 2 is formed by the abutting plate members 1d and 2d, which are separate from the plate main bodies 1a and 2a, at the portions which are in sliding contact with the restraining plates 8a and 8b of the axial restraining mechanism 8. These separate plate members 1d and 2d have guide holes 9 and 10 through which the screws 8c of the axial direction restraining mechanism 8 pass, and the guide holes 9 and 10 are in contact with corresponding positions on the counterpart plate. Screwed to concave fitting portions 1e and 2e provided in the plate main bodies 1a and 2a so as to be orthogonal to the guide holes of the plate member. The plate bodies 1a and 2a are provided with notches 11 and 12 along the peripheral edges of the guide holes 9 and 10, and the restricting plates 8a and 8b are fitted into the notches 11 and 12, respectively. Yes.

  As a result, when the rotational axes of the input / output shafts A and B are displaced, the screws 8c of the axial restraint mechanism 8 are guided by the guide holes 9, 10 of the plate members 1d and 2d as the plates 1 and 2 rotate. Power is transmitted while the restraint plates 8a and 8b slide on the plate members 1d and 2d.

  Here, the material of the abutting plate members 1d and 2d of each plate 1 and 2 and the method of finishing and finishing are the groove members 1b and 2b of each plate 1 and 2 and the holes of the cage 4 of the first embodiment. It is the same as the member 4b.

  The shaft coupling of this embodiment is configured as described above, and is provided with the axial restraint mechanism 8 and the plate members 1d and 2d of the plates 1 and 2 that are in sliding contact with the restraint plates 8a and 8b are subject to surface damage and early wear. Therefore, it is possible to suppress backlash in the axial direction during power transmission while ensuring reliability and durability. Further, as in the first embodiment, the plate members 1d and 2d that have been finished in advance are fixed to the fitting portions 1e and 2e of the plate bodies 1a and 2a, so that the dimensional accuracy of the plates 1 and 2 is as follows. The processing of the plate members 1d and 2d is relatively simple.

  In each of the above-described embodiments, the contact portion between the rotating member and the rolling element of the cage, or the contact portion with the restraining member of the rotating member when the axial direction restraining mechanism is provided, as a separate body from each main body member, Although the hardness is increased by forming the surface with a hardened metal, these separate members may be formed with a hard metal such as a titanium alloy to increase the hardness.

  By the way, when performing normal induction hardening as a surface hardening treatment for another member formed of high carbon steel, carburized steel or the like as in each embodiment, an oxide scale is generated on the surface of the other member by heating in air. For this reason, scale removal processing such as buffing is necessary after quenching treatment, and the time required for the heat treatment process becomes longer, and the processing cost increases due to wear of the buff brush, and the work environment deteriorates due to dirt, dust, etc. Prone to occur.

  On the other hand, if a quenching process in which another member is induction-heated in oil and then cooled is performed, a surface having almost no scale can be obtained, so that scale removal processing can be eliminated and the above problem can be solved. . Further, since deformation after the quenching process is reduced as compared with normal induction hardening, the processing cost can be reduced by omitting the finishing process. Even when finishing, the machining allowance is small, there is no worry of scraping off the hardened layer, and dimensional control is easy. Furthermore, since a hardened layer can be formed more uniformly, surface damage and early wear can be made more difficult to occur.

  In addition to screwing and caulking as in the embodiment, the means for fixing the separate member to the main body member may be a rotating member or a rotating member if any one of riveting, press-fitting, casting, insert molding and adhesion is adopted. The cage can be easily assembled.

  In order to further improve the dimensional accuracy of the rotating member and the cage, after finishing the separate member to the main body member, the finishing process may be performed integrally with the main body member.

Side view of shaft coupling of first embodiment (rotary shafts are concentric) Sectional drawing along the II line | wire of Fig.1 (a) 1 is an exploded side view of the shaft coupling of FIG. 1 is a side view showing the usage state of the shaft coupling of FIG. 1 (rotary shaft is eccentric) Sectional drawing along the III-III line of Fig.3 (a) Side view of shaft coupling of second embodiment (rotary shafts are concentric) Sectional view along line IV-IV in Fig. 4 (a) Side view of conventional shaft coupling (rotary shaft is concentric) Sectional drawing along the VV line of Fig.5 (a)

Explanation of symbols

1, 2 Plate 1a, 2a Plate body 1b, 2b Groove member 1c, 2c Fitting portion 1d, 2d Plate member 1e, 2e Fitting portion 3 Steel ball 4 Cage 4a Cage body 4b Hole member 4c Fitting hole 5, 6 Guide groove 7 Long hole 8 Axial restraint mechanism 8a, 8b Restraint plate 8c Screw 8d Lock nut 9, 10 Guide hole 11, 12 Notch A Input shaft B Output shaft

Claims (9)

  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 of a main body member and another member having the guide groove. A shaft coupling characterized by   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 a shaft coupling provided with a container to transmit power between the rotating members via the rolling elements, the cage is separated from a main member and another member having a long hole for accommodating the rolling elements. A shaft coupling formed by   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 a shaft coupling in which power is transmitted between the rotating members via the rolling elements, the rolling elements are spherical and are arranged on the opposite side of the opposing surface of the rotating members. In addition to providing an axial restraint mechanism that sandwiches both rotating members between the two restraining members and restrains a change in the axial interval between both rotating members, each rotating member is slidably contacted with the main body member and the restraining member. A shaft coupling formed by a member.   The shaft coupling according to any one of claims 1 to 3, wherein the separate member is formed of a hard metal or a metal whose surface is hardened.   The shaft coupling according to claim 4, wherein the surface hardening treatment of the separate member is performed by induction hardening in oil.   The shaft coupling according to claim 1, wherein the main body member is formed of a material that is lighter than the separate member.   7. The separate member is fixed to the main body member by any one of screwing, riveting, caulking, press-fitting, casting, insert molding, and adhesion. Shaft coupling.   The shaft coupling according to claim 7, wherein a fitting portion for positioning the separate member is provided on the main body member.   The shaft coupling according to claim 1, wherein the separate member is finished while being fixed to the main body member.

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