JP2019044874A - Reduction gear - Google Patents

Abstract

To provide a compact reduction gear capable of achieving high reduction ratio and suppressing fluctuation of rotating speed and vibration on an output side, and excellent in assembling workability by effectively preventing falling of balls from a retainer in an assembling work.SOLUTION: A reduction gear includes an input-side rotary member having an input plate portion in which a first ball engagement groove is formed, an output-side rotary member having an output plate portion in which a second ball engagement groove is formed, a plurality of balls engaged with both the ball engagement grooves of the input plate portion and the output plate portion axially opposed to each other, and a retainer having a plurality of pockets for retaining the balls movably in a radial direction. The retainer is provided in a state that it cannot be rotated with respect to a rotating shaft, rotation of the input-side rotary member is reduced through the balls engaged with both the ball engagement grooves, and transmitted to the output-side rotary member. Narrow portions are disposed at axial both end portion sides of the pockets of the retainer to permit radial movement of the balls by engagement with the second ball engagement groove and to restrict ball separation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reduction gear.

  A first disc on the input side provided with a ball engagement groove, a second disc on the output side provided with a ball engagement groove, a plurality of balls engaged with the ball engagement groove, and a first A reduction gear provided with a cage that holds a ball and is interposed between a disk and a second disk has already been proposed (for example, Patent Documents 1 and 2). This type of reduction gear is excellent in that it is compact and a large reduction ratio can be obtained.

  The speed reducer proposed in Patent Document 1 has a winding first to intersect a first reference circle of a plane at a constant pitch and a second reference circle of the plane to intersect a constant pitch. The first and second disks provided with the second groove, and the first and second disks are respectively held by the first and second cages. The first holder is fixed and the second holder is rotatably supported via two rolling elements. Since this reduction gear is differential, it is described that a large reduction ratio can be obtained and that a small reduction gear is possible.

  The speed reducer proposed in Patent Document 2 includes a drive cam having a circular cam groove engaged with a ball and offset from the rotation axis by a predetermined distance, and a driven cam provided with a petal-like cam groove engaged with the ball. And a cage having a groove portion for holding the ball radially movably, the drive cam and the driven cam being opposed to each other with the respective cam grooves on both sides with the cage interposed therebetween. And rotatably coupled about the same axis to decelerate the rotation of the drive cam and transmit it to the driven cam through the action of the ball. It is described that this reduction gear is small and manufactured at low cost by relatively simple processing, and it is possible to obtain a reduction gear ratio of about 6.

Japanese Patent Application Laid-Open No. 60-168954 JP-A-5-203009

  In recent years, depending on the application, high rotational accuracy and vibration suppression of the reduction gear are desired. On the other hand, attention is paid to the inequalities of rotational motion between the input side and the output side of the reduction gear, high-dimensional problems such as rotational speed fluctuation on the output side and vibration generation accompanying this, and responses Led to the idea that However, although the reduction gear described in Patent Documents 1 and 2 is excellent in terms of small size and large reduction ratio, it is considered that the rotational movement between the input side and the output side as described above. The problem of inhomogeneous velocity, the fluctuation of rotational speed on the output side and the occurrence of vibration due to this are not noticed, and in the other documents, there has been no concrete proposal so far, we focused on this Is the present invention.

  In view of the above problems, the present invention achieves a small size and high speed reduction ratio, enables suppression of rotational speed fluctuation and vibration on the output side, and effectively allows the ball to fall from the cage during assembly work and the like. It is an object of the present invention to provide a reduction gear which can be prevented and which is excellent in assembling workability.

  The reduction gear of the present invention comprises an input side rotation member having an input plate portion in which a first ball engagement groove is formed, and a second ball engagement groove disposed coaxially with the rotation axis of the input side rotation member. An output side rotation member having an output plate portion formed with the plurality of balls, a plurality of balls engaged with both ball engagement grooves of the input plate portion and the output plate portion opposed in the axial direction, and the balls in the radial direction And a holder having a plurality of pockets movably held, wherein the holder is provided non-rotatably with respect to the rotation axis, and the input side through the balls engaged with the both ball engagement grooves. In the reduction gear transmission in which the rotation of the rotation member is decelerated and transmitted to the output side rotation member, the track center line of the second ball engagement groove is formed by a wavy curve, and the reduction ratio of the reduction gear is i. When the wave-like curve is in charge of the input side rotating member And the ball engaged with the first ball engagement groove engages with the second ball engagement groove at the rotation angle (.theta.) With the output side rotation member at the rotation angle (i.theta.) A narrow portion which is shaped and which allows radial movement of the ball by engaging with the second ball engagement groove and restricts ball dropout on both axial end sides of the pocket of the retainer It is provided.

  According to the present invention, the input side and the output side always rotate synchronously. Moreover, in order to configure in this manner, it is sufficient to determine the groove shape, and the configuration is not complicated. In addition, since narrow portions for restricting ball removal are provided on both axial end sides of the pocket of the cage, if the ball is incorporated in the pocket of the cage, it is possible to effectively prevent the ball from coming off the pocket it can.

  The cage includes an overlapping body of first and second members, and each of the first and second members is provided with a hole which constitutes the pocket when the first and second members are overlapped. The first member has a first concave surface for forming a narrow portion on the side of the input plate in the hole of the first member, and the hole on the second member has a narrow portion on the side of the output plate. The ball has a gap in each pocket by forming a superposed body in a state of having the second concave surface and interposing the ball inserted in each pocket between the first and second members. It is preferable to be inserted in the state.

  According to this structure, the cage in which the ball is incorporated in the pocket can be simplified by forming the laminated body with the ball inserted in the pocket interposed between the first and second members. It can be configured. Moreover, since the narrow portion at the input plate portion side can be constituted by the first concave surface of the first member and the narrow portion at the output plate portion side can be constituted by the second concave surface of the second member, the ball can be obtained. It can be stored stably in the pocket, and the radial movement of the ball by engaging with the second ball engagement groove can be stabilized and smooth deceleration can be performed. The contact surface between the ball and the cage can be arced, and the contact surface pressure can be reduced by increasing the contact area, and the durability can be improved.

  The pocket of the cage is radially outward or diameter-wise more than the radial movement range of the ball by engaging the second ball engagement groove with the main body portion having the narrow portion constituted by the concave curved surface A ball insertion portion provided inward in the direction may be provided. When the reduction gear is operating normally, the ball is not positioned at the ball insertion portion, and the ball does not drop out of the pocket during operation. Moreover, the ball can be incorporated (stored) in the pocket through the ball insertion portion, and by positioning the incorporated ball in the main body portion, removal of the ball from the pocket can be effectively prevented. Radial movement of the ball by engagement with the second ball engagement groove is permitted.

  A part or all of the narrow portion of the pocket of the cage may be constituted by a radially inward raised portion of the pocket formed by plastic working. Further, one of the narrow portion formed at one axial end of the pocket of the cage and the narrow portion formed at the other axial end is formed of a concave surface, and the other one The part or the whole may be configured by a radially inward raised portion of the pocket formed by plastic working.

  According to the present invention, it is possible to realize a small-sized and high reduction ratio, and to realize a reduction gear that can suppress the rotational speed fluctuation and vibration on the output side. In addition, if the ball is incorporated into the pocket of the cage, the ball can be effectively prevented from coming off from the pocket, so that the assemblability can be improved, and during transportation (during transportation), etc. It is possible to prevent the falling off, to prevent the occurrence of pockets into which the ball can not be incorporated, and to increase the yield.

It is a sectional view showing the 1st reduction gear. It is a disassembled perspective view which shows the principal part of FIG. It is a perspective view which shows the input-plate part of the retarding apparatus shown in FIG. 1, a holder, and an output-plate part. It is a side view of the input board part which looked at the arrow of the EE line of FIG. It is sectional drawing of the input-plate part in the GG line | wire of FIG. 4A. It is a side view of the output board part which looked at the arrow by the FF line of FIG. It is sectional drawing of the output-plate part in the HH line | wire of FIG. 5A. FIG. 2 is a side view of the cage taken along line I-I in FIG. It is an enlarged view of the J section of FIG. 6A. It is a figure which shows the arrangement | positioning state of the ball | bowl engagement groove | channel of an output board part, and a ball. FIG. 7 is a view showing the movement of the ball relative to the ball engagement groove. It is a schematic diagram which derives the standard curve of the ball engagement slot of an output board part. It is a side view of an input board part which has a ball engagement slot of a gothic arch shape. It is sectional drawing of the input-plate part in the G1-G1 line of FIG. 10A. It is a side view of an output board part which has a ball engagement slot of a gothic arch shape. It is sectional drawing of the output-plate part in the H1-H1 line | wire of FIG. 11A. It is a sectional view showing the 2nd reduction gear. It is a perspective view which shows the principal part of the reduction gear shown in FIG. FIG. 13 is a perspective view showing an input plate portion, a holder and an output plate portion of the reduction gear shown in FIG. 12. It is a side view which shows the input-plate part of the retarding apparatus shown in FIG. It is the CC sectional view taken on the line of FIG. 15A. It is a side view which shows the output-plate part of the retarding apparatus shown in FIG. It is the DD sectional view taken on the line of FIG. 16A. It is a schematic diagram which derives | requires the standard curve of the ball | bowl engagement groove | channel of the output-plate part of the retarding apparatus shown in FIG. FIG. 7 is a graph showing the relationship between the rotation angle of the input plate portion and the trajectory of one reciprocation of the ball, in which the groove of the input plate portion is circular. It is a graph which shows the relationship between the rotation angle of an input board part, and the locus | trajectory of 1 reciprocation of a ball | bowl, and the groove | channel of an input board part in the case of polygonal cylindrical shape. It is a side view showing the input board part which has a ball engagement slot of a gothic arch shape. It is the C1-C1 line sectional view of Drawing 19A. It is a side view showing the output board part which has a ball engagement slot of a gothic arch shape. It is the D1-D1 line sectional view of Drawing 20A. It is a sectional view of the reduction gear provided with a rotation control mechanism. It is a principal part expanded sectional view of the reduction gear shown in the said FIG. It is the principal part simplified view seen from the input side of the input-plate part of the retarding apparatus shown in the said FIG. It is the principal part simplified view seen from the output side of the side wall of the input side of the case of the retarding apparatus shown in the said FIG. It is a side view of the 1st holder which has a narrow part in a pocket. It is the A1-A1 line expanded sectional view of the said FIG. It is a B1-B1 line expanded sectional view of the said FIG. It is a perspective view of the 2nd holder which has a narrow part in a pocket. It is a side view of the holder shown in the said FIG. It is the A2-A2 line expanded sectional view of the said FIG. It is the B2-B2 line expanded sectional view of the said FIG. It is a side view of the 3rd holder which has a narrow part in a pocket. It is the A3-A3 line expanded sectional view of the said FIG. It is a side view of the 4th holder which has a narrow part in a pocket. It is the A4-A4 line expanded sectional view of the said FIG. FIG. 26 is a perspective view of a reduction gear (before assembly) using the holding shown in FIG. 25. It is a block diagram which shows the assembling method of a reduction gear.

  1 to 9 show a first reduction gear. This reduction gear transmission 1 mainly has an input side rotation member 2, an output side rotation member 3, a ball 4 and a cage 5, and a case 6 (a first member 6a on the input side and a second member 6b on the output side (In the case of being combined).

  As shown in FIG. 1, the input side rotation member 2 includes a rotation shaft 7 as an input shaft, an eccentric cam 8, a rolling bearing 9, and an input plate portion 10 (10 A). An eccentric cam 8 is fitted to the outer diameter surface of the rotating shaft 7. The center line O1 of the cylindrical outer diameter surface 8a of the eccentric cam 8 is radially offset by an eccentricity a with respect to the axial center X1 of the rotation shaft 7 (that is, the device rotation center X). Therefore, the eccentric cam 8 forms an eccentric portion on the rotary shaft 7 which is an input shaft. A rolling bearing 9 is mounted between the cylindrical outer diameter surface 8a of the eccentric cam 8 and the cylindrical inner diameter surface 10a of the input plate portion 10A, and the input plate portion 10A is rotatably supported by the eccentric cam 8. The center line O1 of the cylindrical outer diameter surface 8a of the eccentric cam 8 is also the center line of the input plate portion 10A. For this reason, when the rotation shaft 7 rotates, the input plate portion 10A revolves around the axial center X1 of the rotation shaft 7 with a swing radius a. The rotating shaft 7 is rotatably supported by the rolling bearing 11 mounted on the inner diameter surface 21 of the first member 6 a of the case 6 and the rolling bearing 12 mounted on the inner diameter surface 5 a of the cage 5.

  As shown in FIGS. 1, 4A and 4B, a first ball engagement groove 13 is formed on the side surface 10b of the input plate 10A. FIG. 4A is a side view of the input plate 10A taken along the line E-E in FIG. 1, and FIG. 4B is a cross-sectional view of the input plate 10A taken along the line G-G in FIG. 4A. In FIGS. 4A and 4B, the chamfering of the outer diameter surface of the input plate portion 10A and the illustration of the inner diameter surface 10a (see FIG. 1) on which the rolling bearing 9 is mounted are omitted.

  As shown in FIG. 4A, the track center line L1 of the first ball engagement groove 13 is formed in a circle having a radius r, and the first ball engagement groove 13 is formed of a part of the torus surface. The center of curvature of the orbit center line L1 is located at the cylindrical outer diameter surface 8a of the eccentric cam 8 and the center line O1 of the input plate portion 10A. The curvature center O1 is eccentric with respect to the axial center X1 of the rotary shaft 7 by an eccentricity a. The center Ob of the ball 4 is positioned on the track center line L 1 of the first ball engagement groove 13. In the present specification and claims, the track center line of the first ball engagement groove is the locus of the center Ob of the ball 4 when the ball 4 is moved along the first ball engagement groove 13. Means

  As shown in FIG. 1, the output side rotation member 3 is composed of an output plate portion 30 (30A) and a shaft portion 31, and the output plate portion 30A and the shaft portion 31 are integrally formed. The shaft 31 is an output shaft. The output side rotation member 3 is rotatably supported by a rolling bearing 14 mounted on the inner diameter surface 20 of the second member 6b of the case 6 and a rolling bearing 15 mounted on the step outer diameter surface 5b of the cage 5 There is.

  As shown in FIGS. 1, 5A and 5B, the second ball engagement groove 16 is formed on the side surface 28 of the output plate 30A. FIG. 5A is a side view of the output plate 30A as viewed in the direction of the arrows F-F in FIG. 1, and FIG. 5B is a cross-sectional view of the output plate 30A at the line HH in FIG. 5A. In FIGS. 5A and 5B, the chamfering of the outer diameter surface of the output plate 30A and the illustration of the inner diameter surface 22 (see FIG. 1) on which the rolling bearing 15 is mounted are omitted.

  The track center line L2 of the second ball engagement groove 16 is formed by a wavy curve, and the axial center X2 of the shaft 31, the track center line L2 and the distance R increase or decrease with respect to the reference pitch circle radius PCR. In the embodiment, in the wavelike curve of the track center line L2, ten peaks having a distance R larger than the reference pitch circle radius PCR and ten valleys having a distance R smaller than the reference pitch circle radius PCR are formed. There is. The axial center X2 of the shaft portion 31 is coaxially arranged with the axial center X1 of the rotation shaft 7. The center Ob of the ball 4 is located on the track center line L 2 of the second ball engagement groove 16.

  In the first embodiment, the wavy curve of the track center line of the second ball engagement groove means a curve alternately intersecting with the reference pitch circle of the radius PCR at a constant pitch. Further, the track center line of the second ball engagement groove means the locus of the center Ob of the ball 4 when the ball 4 is moved along the second ball engagement groove 16. Details of the wavy curve of the track center line L2 of the second ball engagement groove 16 will be described later.

  As shown in FIG. 1, the cage 5 is disposed between the side surfaces 10b, 28 opposed in the axial direction of the input plate portion 10A and the output plate portion 30A. The holder 5 is provided with a pocket 17 for holding the ball 4. A through hole 18 is provided on the outer peripheral side of the holder 5, and a pin 19 is inserted into the through hole 18, and the holder 5 is non-rotatably attached to the case 6. Thereby, the rotation shaft 7 of the input side rotation member 2 can rotate with respect to the holder 5. In this state, the fixing bolt 24 is inserted into the through hole 25 of the second member 6b and the through hole 23 of the holder 5, and screwed into the screw hole 26 of the first member 6a to form the first member 6a and the second member. 6b and the retainer 5 are fastened.

  As shown in FIGS. 1, 6A and 6B, the pocket 17 of the holder 5 is formed by an elongated hole radially extending in the radial direction centering on the axial center X1 of the rotation shaft 7. 6A is a side view of the cage taken along line I-I in FIG. 1, and FIG. 6B is an enlarged view of a portion J in FIG. 6A. 6A and 6B, illustration of the through holes 18 and 23 on the outer peripheral side of the cage 5 in FIG. 1 and the inner diameter surface 5a to which the rolling bearing 12 is mounted is omitted.

  The number of pockets 17 of the cage 5 is eleven, which is one more than the number (10) of the peaks or valleys of the wavy curve of the track center line L2, and the pockets 17 are formed at equal intervals in the circumferential direction There is. One ball 4 is disposed in each pocket 17. Since each pocket 17 is formed by an elongated hole extending radially in the radial direction, the balls 4 in each pocket 17 have a predetermined amount m in the radially outer side and the radially inner side with respect to the reference pitch circle radius PCR. It can move. The holder 5 is non-rotatably provided, and the ball 4 is radially movably held by the pocket 17 of the holder 5.

In the first reduction gear 1, the number of peak portions of the track center line L2 of the second ball engagement groove 16 is 10 (the number of valleys is also 10), and the number of balls 4 is 11 Therefore, the reduction gear ratio i is determined by the following equation, and the reduction gear ratio i is −1/10.
Reduction ratio i = (number of peaks-number of balls) / number of peaks

  That is, the output plate portion has N-poles / peripheral waved grooves (the number N of peak portions per round), and the output plate portion is rotationally driven by movement of the ball along the waved grooves. Therefore, the speed reduction ratio is represented by i = (N−n) / N. Here, n is the number of balls, and N is the number of poles of the wavy groove. However, since the ball number n is configured by N ± 1, the reduction ratio i is i = − (± 1) / N, and in the case of a plus, the input plate portion and the output plate portion rotate in the same direction, In the case of minus, the input plate portion and the output plate portion rotate in the opposite direction.

  Next, with reference to FIG. 2 and FIG. 3, the combination state of the input plate portion 10A, the holder 5, the ball 4 and the output plate portion 30A will be described. FIG. 2 is a perspective view showing an essential part of FIG. 1, and FIG. 3 is a schematic view of a state in which the ball of FIG. 2 is disposed in a pocket of a cage. In FIG. 3, the outer diameter chamfering of the input plate portion 10A in FIG. 2, the inner diameter surface 10a for bearing mounting, the outer diameter side through holes 18 and 23 of the cage 5, the inner diameter surface 5a for bearing mounting, and the bearing mounting of the output plate portion 30A. The illustration of the inner diameter surface 22 and the shaft 31 is omitted.

  The axial center X1 of the rotation shaft 7 of the input side rotational member 2 and the axial center X2 of the output side rotational member 3 are coaxially arranged, and the axial center of the cage 5 is coaxially arranged with the axial centers X1 and X2 . The center of curvature O1 (see FIG. 4A) of the track center line L1 of the first ball engagement groove 13 of the input plate portion 10A is eccentric to the axis X1 of the rotary shaft 7 by the eccentricity a. In other words, the radial center of the track center line L1 of the first ball engagement groove 13 of the input plate portion 10A is eccentric with respect to the axial center X1 of the rotation shaft 7 by the eccentricity a.

  Although FIG. 2 shows the ball 4 engaged with the second ball engagement groove 16 of the output plate portion 30A, the ball 4 is disposed in the pocket 17 of the cage 5 and the pocket 17 The ball 4 is projected to the front side, and the ball 4 is engaged with the first ball engagement groove 13 (see FIG. 1) of the input plate portion 10A. That is, as shown in FIG. 3, the front side of the drawing of the ball 4 in the pocket 17 of the holder 5 is engaged with the first ball engagement groove 13 (see FIG. 1) of the input plate portion 10A, and the drawing of the ball 4 The back side engages with the second ball engagement groove 16 of the output plate portion 30A.

  The overall configuration of the reduction gear transmission 1 of the first embodiment is as described above. Next, the details of the ball engagement groove that rotates synchronously with the output side rotation member being decelerated with respect to the input side rotation member will be described based on FIGS. 7 to 9. FIG. 7 is a view showing the arrangement of the second ball engagement groove of the output plate portion and the ball, and FIG. 8 is an enlarged view of a portion K of FIG. 7 showing the movement of the ball relative to the second ball engagement groove. FIG. 9 is a schematic diagram for deriving a reference curve of the second ball engagement groove of the output plate portion.

As described above, the cage 5 is non-rotatably provided, and the balls 4 are radially movably held by the pockets 17 of the cage 5. As shown in FIG. 7, the balls 4 engage with the second ball engagement grooves 16 of the output plate 30A at equal angular positions in the circumferential direction. In this embodiment, since the number of balls 4 is eleven, assuming that an angle formed by a straight line connecting the center Ob _{2 of the} ball 4 adjacent to the axial center X 2 and the circumferential direction with α is α = 360 °. The angle α between all the adjacent balls 4 is equal to 11.

  A state in which the output side rotation member 3 is decelerated with respect to the input side rotation member 2 and synchronously rotated will be described based on FIG. As described above, the holder 5 is configured to be non-rotatable with respect to the rotation of the input side rotation member 2 and the output side rotation member 3. Therefore, the pocket 17 shown by a solid line in FIG. 8 does not move in the circumferential direction. The horizontal center line in FIG. 8 indicates the position where the rotation angle θ of the rotation shaft 7 of the input side rotation member 2 is 0 °. The ball 4 is located radially outward in the pocket 17. This is because, in the revolution movement of the input plate portion 10A, the first turning of the input plate portion 10A is because the swing radius a of the rotational axis 7 of the input plate portion 10A with respect to the axial center X1 of The ball 4 engaged with the ball engagement groove 13 is located radially outward in the pocket 17.

Since the rotation shaft 7 is rotated angle theta ₁ is rotated, the position of the whirling radius a of the input plate portion 10A moves to the position of the rotation angle theta _1, engage the first ball engagement groove 13 of the input plate portion 10A The ball 4 moves radially inward in the pocket 17, and the center of the ball 4 is at the position of Ob ₁ . Since the ball 4 engages with the second ball engagement groove 16 of the output plate portion 30A when the center of the ball 4 is at Ob ₁ , in other words, the center Ob ₁ of the ball 4 is the second ball engagement In order to be positioned on the track center line L2 of the groove 16, the output plate portion 30A is rotated by _one rotation angle iθ shown in FIG. Subsequently, when the rotation shaft 7 rotates to the rotation angle θ ₂ and further to the rotation angles θ ₃ and θ ₄ , the output plate unit 30 A rotates to the rotation angles iθ ₂ , iθ ₃ and iθ ₄ as described above. . Thereby, the rotational movement decelerated (reduction ratio i = −1 / 10) is transmitted from the input side rotation member 2 to the output side rotation member 3.

  The reduction gear transmission 1 of the first embodiment is characterized in that the rotational motion decelerated from the input side rotation member 2 to the output side rotation member 3 is transmitted by synchronous rotation. Thereby, high rotational accuracy and vibration suppression can be achieved. In order to transmit the rotational motion decelerated from the input side rotation member 2 to the output side rotation member 3 by synchronous rotation, the shape of the wavy curve of the track center line L2 of the second ball engagement groove 16 of the output plate portion 30A Is set.

A method of deriving the wavy curve of the track center line L2 of the second ball engagement groove 16 of the output plate portion 30A will be described based on FIG. FIG. 9 is a schematic view for deriving a wavy curve of the track center line L2 of the second ball engagement groove 16. As shown in FIG. The center line in the horizontal direction in FIG. 9 corresponds to the center line in the horizontal direction in FIG. 8, and indicates a position where the rotation angle θ of the rotation shaft 7 of the input side rotation member 2 is 0 °. The track center line L1 ₀ of the first ball engagement groove 13 of the rotation angle of the rotary shaft 7 theta is 0 ° Noto input plate portion 10A denoted by the dashed line, the first ball at any rotation angle theta The track center line L1θ of the engagement groove 13 is indicated by a solid line.

The track center line L1 of the first ball engagement groove 13 of the input plate portion 10A is circular with respect to the axis X1 of the rotation shaft 7 of the input side rotation member 2 and the curvature center O1 is an eccentricity It is eccentric only by a. Therefore, the center of curvature of the raceway center line L1 when the rotational angle θ is 0 ° is in the O1 _0, the center of the ball 4 is the outermost radially Ob _0. The pockets 17 of the retainer 5 restrain the ball 4 on the line n1 and allow radial movement. When the rotation axis 7 reaches an arbitrary rotation angle θ, the curvature center of the orbit center line L1 moves to O1θ, and the center of the ball 4 moves to Obθ. The ball 4 in this position engages with the second ball engagement groove 16 of the output plate 30A. That is, the center Obθ of the ball 4 is positioned on the track center line L2 (see FIG. 8) of the second ball engagement groove 16. With this positional relationship, the synchronous rotation of the rotary shaft 7 and the output plate portion 30A is established such that the rotational angle of the output plate portion 30A is always iθ with respect to any rotational angle θ of the rotary shaft 7. Based on this, the distance R between the axial center X1 of the rotary shaft 7 and the track center line L2 of the second ball engagement groove is geometrically determined.

As shown in FIG. 9, the distance R between the axial center X1 of the rotary shaft 7 and the orbit center line L2 of the second ball engagement groove is expressed as the following equation 1.

That is, as can be seen from FIG. 9, the following equations 2, 3, 4, 5, and 6 hold.

  Here, in order to rotate the reduction gear synchronously, it is necessary to establish a reduction ratio i = ψ / θ. Therefore, it is possible to obtain the equation of the equation 1 from the equation 6.

  The operation of the reduction gear transmission 1 of the first embodiment will be summarized and described. When the rotation shaft 7 of the input side rotation member 2 is rotated, the input plate portion 10A revolves around the axial center X1 of the rotation shaft 7. At that time, since the input plate portion 10A is freely rotatable with respect to the eccentric cam 8 provided on the rotation shaft 7, the input plate portion 10A hardly performs rotational movement. Thereby, the amount of relative friction between the pocket of the cage and the ball engagement groove and the ball can be reduced, and the transmission efficiency from the input side rotation member to the output side rotation member can be improved.

  When the input plate portion 10A performs a revolution movement, each ball 4 engaged with the first ball engagement groove 13 formed of the circular track center line L1 is restrained in the pocket 17 of the retainer 5 provided non-rotatably. And each move radially.

  Each ball 4 is engaged with the second ball engagement groove 16 of the output plate portion 30A of the output side rotation member 3, so that each ball 4 is shown in FIG. Thus, the rotation of the rotation shaft 7 of the input side rotation member 2 is decelerated and the output side rotation member 3 is rotated. At that time, the reference curve of the track center line L2 of the second ball engagement groove 16 of the output plate portion 30A is set as described in FIG. Synchronized rotation at the reduced speed.

  The operation of the reduction gear transmission 1 of the first embodiment is as described above, and a small reduction gear having a high reduction ratio can be obtained, and a reduction gear transmission that can suppress rotational speed fluctuation and vibration on the output side can be realized. Can. In addition, the first ball engagement groove consisting of a circular track center line and the second ball engagement groove consisting of a track center line of a wave-like curve can simplify the shape of the ball engagement groove as a whole, which is easy to manufacture Cost reduction can be achieved.

  As shown in FIGS. 10A and 10B, the first ball engagement groove 13 may have a so-called gothic arch-shaped ball engagement groove 13A. In this case, as shown in FIG. 10B, the ball 4 makes angular contact with the ball engagement groove 13A of the input plate portion 10A at two points C12 and C13. In this case, a contact angle which is an angle formed by the contact points C12 and C13 can be set to, for example, about 30 ° to 40 °. Hatching of Drawing 10B has shown a contact portion.

  Further, as shown in FIGS. 11A and 11B, the second ball engagement groove 16 may also be a ball engagement groove 16A whose cross-sectional shape is a so-called gothic arch shape. In this case, as shown in FIG. 11B, the ball 4 is in angular contact with the ball engagement groove 16A of the output plate 30A at two points C15 and C16. In this case, a contact angle which is an angle formed by the contact points C15 and C16 can be set to, for example, about 30 ° to 40 °. The hatching in FIG. 11B indicates the contact portion.

  The ball engagement groove 13 is a gothic arch shaped ball engagement groove 13A as shown in FIGS. 10A and 10B, and the ball engagement groove 16 is a gothic arch shaped ball engagement as shown in FIGS. 11A and 11B. In the case of the mating groove 16A, the ball can be positioned stably and the synchronous rotation characteristic (constant velocity) can be enhanced. For this reason, it is possible to provide a high-quality transmission with excellent durability.

  12 to 16 show a second reduction gear, and the input plate 10 (10B) of the reduction gear is different from the input plate 10A of the reduction gear of the first embodiment, as shown in FIG. 15A. As shown in the figure, the first ball engagement groove 13B having a polygonal cylindrical shape is provided. Further, the output plate portion 30 (30B) in this case has a second ball engagement groove 16B formed of a corrugated groove, like the output plate portion 30B of the reduction gear transmission of the first embodiment.

  Also in this case, since the input plate portion 10B is externally fitted to the eccentric cam 8, the center of the ball engagement groove 13B is eccentric by a predetermined amount a with respect to the axial center of the rotation shaft. 12-16 is the same as that of the said 1st Embodiment of the other structure of the retarding apparatus which concerns on this invention. For this reason, about this other structure, the same code | symbol as the retarding apparatus of 1st Embodiment shown by FIG. 1 etc. is attached | subjected, and those description is abbreviate | omitted.

FIG. 17 is a schematic diagram for deriving the wavy curve of the track center line (reference curve) of the second ball engagement groove 16B. The center line in the horizontal direction in FIG. 17 corresponds to the center line in the horizontal direction in FIG. 8, and indicates a position where the rotation angle θ of the rotation shaft 7 of the input side rotation member 2 is 0 °. The track center line L3 ₀ of the first ball engagement groove 13B of the input plate portion 10B when rotation angle of the rotary shaft 7 theta of 0 ° is represented by a broken line, the first ball at any rotation angle theta The track center line L3θ of the engagement groove 13B is indicated by a solid line.

The orbit center line L3 of the first ball engagement groove 13B of the input plate portion 10B is polygonal with respect to the axial center X1 of the rotation shaft 7 of the input side rotation member 2 and the center O3 thereof is offset by the eccentricity a. I have a heart. Therefore, the center of curvature of the raceway center line L3 when the rotational angle θ is 0 ° is in the O3 _0, the center of the ball 4 is the outermost radially Ob _0. The pockets 17 of the retainer 5 allow the ball 4 to move radially. When the rotation axis 7 reaches an arbitrary rotation angle θ, the center of curvature of the trajectory center line L3 moves to O3θ, and the center of the ball 4 moves on L3 indicated by a solid line. The ball 4 in this position engages with the second ball engagement groove 16 of the output plate portion 30. That is, the center Obθ of the ball 4 is positioned on the track center line L2 (see FIG. 8) of the second ball engagement groove 16. With this positional relationship, the synchronous rotation of the rotating shaft 7 and the output plate unit 30 is established that the rotating angle of the output plate unit 30 is always iθ with respect to an arbitrary rotating angle θ of the rotating shaft 7. Based on this, it is possible to geometrically obtain the distance R between the axial center X1 of the rotary shaft 7 and the orbit center line L2 of the second ball engagement groove 16B.

In the reduction gear according to the present invention shown in FIG. 12 and the like, as shown in FIG. 17, the distance R between the axial center X1 of the rotation center axis and the center of the ball 4 is represented by the following formula 7.

That is, as can be seen from FIG. 17, the following mathematical expressions 8, 9, and 10 hold.

ここで、この減速装置が同期回転するため、減速比ｉ＝ψ／θが成り立つ必要がある。このため、この数１０から前記数７の数式を求めることができる。

Here, in order to rotate the reduction gear synchronously, it is necessary to establish a reduction ratio i = ψ / θ. Therefore, it is possible to obtain the equation of the equation 7 from the equation 10.

  By the way, when the groove 13 of the input plate portion 10 is a circular groove as in the first embodiment, when the input plate portion 10 makes one rotation, the ball 4 is moved to the elongated hole 17 (pocket) in the cage 5. It reciprocates, and the output plate part 30 rotates i. (0 ° ≦ θ ≦ 360 °) of the input plate portion 10 is divided into four quadrants (0 ° to 90 °, 90 ° to 180 °, 180 ° to 270 °, 270 ° to 360 °), and each quadrant The characteristics of the first reduction gear and the second reduction gear can be confirmed by paying attention to the movement of the ball in the above.

  The rotation angle when the offset amount of the input plate unit 10 is maximum is dθ = 0 °, and the ball 4 to be observed is the ball farthest from the rotation axis when dθ = 0. Among the distances when the ball 4 makes one reciprocation in the long hole 17 provided in the holder 5, the movement distance of the ball 4 when the rotation angle dθ of the input plate portion 10 is the first quadrant is La1 (see FIG. 6B) ), The second quadrant is La2 (see FIG. 6B), the third quadrant is La3 (see FIG. 6B), and the fourth quadrant is La4 (see FIG. 6B). Comparing (or La3 and La4), the first embodiment is clearly different from FIG. 18A.

  That is, when the grooves 13 of the input plate portion 10 are circular, as shown in FIG. 18A, the lengths of La1 and La2 (or La3 and La4) are different. This shows that, in one reciprocation in which the ball 4 rolls the elongated hole 17 in the cage 5, the moving distance on the outer side in the radial direction about the pitch circle is different from the moving distance on the inner side in the radial direction. In order to satisfy the synchronous rotation characteristics (ψ = iθ) of the rotation angle θ of the output plate portion 30 and the rotation angle θ of the plate, the velocity fluctuation of the ball 4 in the long hole 17 of the cage 5 is a diameter centered on the pitch circle. Indicates that the direction is different on the outside and the inside. This indicates that the velocity fluctuation of the ball rolling on the wavy groove 16 of the output plate portion 30 is different between the radially outer side and the inner side centering on the pitch circle, which may lead to the generation of vibration and noise.

  On the other hand, when the groove 13 of the input plate portion 10 is polygonal, as shown in FIG. 18B, the lengths of La1 and La2 (or La3 and La4) become equal. This is because, within one cycle in which the ball 4 rolls in the long hole 17 of the cage 5 and the waved groove 16 of the output plate 30, the radial outer moving distance and the radial inner moving distance centering on the pitch circle In the same manner (= single vibration), while maintaining the synchronous rotation characteristics (ψ = iθ) of the rotation angle θ of the input plate portion 10 and the rotation angle ψ of the output plate portion 30, the velocity fluctuation of the ball is centered on the pitch circle. Show that they are equal on the radially outer side and the inner side.

  Therefore, by forming the groove 13 of the input plate portion 10 into a polygonal shape (polygonal cylindrical shape), it is possible to improve the synchronous rotation characteristic (constant velocity) of the input plate portion 10 and the output plate portion 30. By this, it is possible to suppress the rotational speed fluctuation and vibration on the output side as much as possible.

  According to the second reduction gear, as in the first reduction gear, the input side and the output side always rotate in synchronization, thereby providing a high quality reduction gear with less rotational speed fluctuation and vibration on the output side. it can. In addition, it is possible to miniaturize and obtain a high reduction ratio. In addition, in order to always rotate in synchronization with the input side and the output side, it is sufficient to determine the groove shape without causing complication in the configuration. In particular, by setting the groove shape of the input plate portion 10 to the same number of polygonal cylinders as the number of balls 4, it is possible to improve the synchronous rotation characteristics (constant velocity) on the input side and the output side.

  Further, when the number of balls 4 is n and the number of poles of the wavy groove 16 of the output plate portion 30 is N, the reduction ratio is i so that i = (N−n) / N It is possible to stably provide a reduction gear that can be set, small in size and high in reduction ratio.

  An input plate portion 10B is externally fitted with an eccentric portion of the input shaft 7 via a bearing, and the output plate portion 10B is provided with a case 6 which rotatably accommodates the input plate portion 10B and the output plate portion 30B and fixes the holder. Since 30 B is integrated with the output shaft 31 rotatably supported on the case 6 via a bearing, a compact reduction gear can be formed.

  Also in the reduction gear shown in FIGS. 14 to 18B, the first ball engagement groove 13 has a so-called gothic arch-shaped ball engagement groove 13B as shown in FIGS. 19A and 19B. May be In this case, as shown in FIG. 19B, the ball 4 makes angular contact with the ball engagement groove 13B of the input plate portion 10A at two points C22 and C23. In this case, a contact angle which is an angle formed by the contact points C22 and C23 can be set to, for example, about 30 ° to 40 °. The hatching in FIG. 19B indicates the contact portion.

  Further, as shown in FIGS. 20A and 20B, the second ball engagement groove 16 may also be a ball engagement groove 16B whose cross-sectional shape is a so-called gothic arch shape. In this case, as shown in FIG. 20B, the ball 4 is in angular contact with the ball engagement groove 16B of the output plate 30A at two points C25 and C26. In this case, a contact angle which is an angle formed by the contact points C25 and C26 can be set to, for example, about 30 ° to 40 °. The hatching in FIG. 20B indicates the contact portion.

  The ball engagement groove 13 is a gothic arch shaped ball engagement groove 13B as shown in FIGS. 19A and 19B, or the ball engagement groove 16 is a gothic arch shaped ball engagement as shown in FIGS. 20A and 20B. If it is the mating groove 16B, the ball can be positioned stably, and the synchronous rotation characteristic (uniform velocity) can be enhanced. For this reason, it is possible to provide a high-quality transmission with excellent durability.

  By the way, when the grooves 13 of the input plate portion 10 have a polygonal shape, in order to maintain the relative positional relationship characteristic between the grooves 13 of the input plate portion 10 and the elongated holes (pockets) 17 of the cage, the rotation of the input plate portion 10 It is preferable to restrict the rotation and allow only revolution. For this reason, as shown in FIGS. 21 and 22, the input is made between the input plate portion 10 and the wall surface on the fixed side facing this (in this case, the inner side surface 6a1 of the side wall on the input side of the case 6) It is preferable to provide a rotation restricting mechanism M which restricts the rotation of the plate portion 10 and permits revolution.

  A plurality of rotation restricting mechanisms M are provided on the input side surface 10c of the input plate portion 10B along the circumferential direction at predetermined pitches (in this embodiment, eight at 45 ° pitches as shown in FIG. 23). A plurality of annular track grooves 55 and an inner side surface 6a1 of the first member 6a of the case 6 opposed to the side surface 10c on the input side of the input plate portion 10B at a predetermined pitch along the circumferential direction (as shown in FIG. An annular raceway groove 56 provided at a pitch of 45 ° and a rolling element 57 interposed between the raceway groove 55 and the raceway groove 56 opposed thereto. In this case, the ring center O5 of the raceway groove 55 and the ring center O6 of the raceway groove 56 are eccentric. At this time, it is preferable that the ring center O5 of the raceway groove 55 and the ring center O6 of the raceway groove 56 be decentered in the opposite direction by 180 °. Peak portions 55a, 56a are formed at the centers of the raceway grooves 55 and the raceway grooves 56, and the axial centers of the mountain portions 55a, 56a become annular centers O5, O6.

  If such a rotation restriction mechanism M is provided, rotation of the input plate portion 10 is restricted and revolution is allowed, and the groove 13 of the input plate portion 10 and the long hole (pocket) 17 of the retainer 5 are It is possible to maintain the mutual positional relationship, and stably prevent the occurrence of vibration. In addition, increase / decrease in the number of the track groove 55 (56) of the rotation control mechanism M is also arbitrary.

  In the above-described reduction gear, the reduction ratio is determined by the wave number of the second ball engagement groove 16 and the like, and the position where the ball 4 can exist is also determined by these. In addition, although the smaller the reduction ratio (the wave number etc. of the second ball engagement groove 16 is large), more balls 4 can be arranged, but the more balls 4 increase the work of inserting the balls 4 into the pockets 17. It becomes easy for the case to forget a pair. Moreover, in the said reduction gear, the contact of the ball | bowl 4 and the pocket 17 of the holder | retainer 5 is a "ball" and a "plane", and the clearance gap is managed by what is called "spacing." Therefore, even if the ball 4 is inserted into the pocket 17 of the holder 5 before assembling, the ball 4 may fall off the pocket 17.

  Then, the holder 5 which has the pocket 17 as shown to FIGS. 25-27 was proposed. In this cage, once the ball 4 is assembled in the pocket 17, the ball 4 can be effectively prevented from falling out of the pocket 17, and moreover, the ball 4 is incorporated in the cage before assembling the reduction gear (holding Container assembly) and it is possible to avoid forgetting to assemble the ball 4 at the time of assembly.

  The holder 5 includes an overlapping body 61 in which the first member 60A and the second member 60B are overlapped. In the pocket 17 in this case, narrow portions 62A and 62B are provided on both axial end sides for restricting the ball coming off. As shown in FIG. 27, the width dimension W of the narrow portions 62A and 62B is set smaller than the diameter Db of the ball 4.

  That is, holes 63A and 63B for forming the pocket 17 are formed in the first and second members 60A and 60B, respectively. In this case, the cross-sectional shapes of the inner peripheral surface of the holes 63A and 63B are concave curved surfaces 63Aa and 63Ba as shown in FIGS. The concave curved surfaces 63Aa and 63Ba have a contact shape with the ball 4 when a stacked body 61 in which the first member 60A and the second member 60B are stacked is configured. In this case, it is preferable to set ball radius ≦ cr ≦ ball radius × 2.0, where cr is the radius of curvature of the concave arc surface 65 formed of the concave surfaces 63Aa and 63Ba. By setting in this manner, the contact stress between the ball 4 and the pocket 17 is reduced.

  The pocket 17 constituted by the holes 63A and 63B is formed by an elongated hole radially extending in the radial direction centering on the axial center X1 of the rotation shaft 7 as in the one shown in FIGS. 6A and 6B and the like. Therefore, radial movement of the ball 4 by engaging with the two ball engaging grooves 16 is permitted.

  Therefore, even if the cage 5 having the pocket 17 as shown in FIGS. 25 to 27 is used, the operation and effect exhibited by the reduction gear 1 can be obtained. Moreover, if the balls 4 are incorporated into the pockets 17 of the cage 5, the balls 4 can be effectively prevented from coming off from the pockets 17. Therefore, the assemblability can be improved, and during transportation (during transportation) Etc.), and it is possible to prevent the occurrence of the pocket 17 in which the pocket 4 is not incorporated, and the yield is increased.

  By the way, in the cage 5 having the pocket 17 as shown in FIG. 25 to FIG. 27, the first and second members 60A and 60B intervene between the first and second members 60A and 60B. The two members 60A and 60B are stacked to form a stacked body. As a result, the ball 4 is inserted into each pocket 17 with a gap.

  Next, although the cage 5 shown in FIGS. 28 to 31 does not use the first member 60A and the second member 60B, a width formed by the concave arc surface 65 having a contact shape with the ball 4 as the pocket 17 The body portion 67 having the narrow portions 62, 62, and the radial movement range (the range shown by m of FIG. 6B) of the ball 4 by engaging the second ball engagement groove 16 And a ball insertion portion 68.

  The main body portion 67 having the narrow portion 62 constituted by the concave arc surface 65 having a contact shape with the ball 4 has the same size and shape as the pocket of the cage 5 shown in FIGS. Further, the inner diameter dimension D2 (see FIG. 29) of the ball insertion portion 68 is set larger than the outer diameter dimension Db (see FIG. 31) of the ball 4, and insertion of the ball 4 into the ball insertion portion 68 is permitted. Ru.

  Therefore, in the case of the cage 5 shown in FIGS. 28 to 31, after the ball 4 is inserted into the ball insertion portion 68 when assembled in the pocket 17, the ball 4 is moved to the main portion 67 having the narrow portion 62. Let This makes it possible to effectively prevent the ball 4 from coming out of the pocket 17. Moreover, since the main body portion 67 has the same size and shape as the pockets of the retainer 5 shown in FIGS. 25 to 27, the balls 4 in the main body portion 67 engage with the second ball engagement grooves 16. Allow for radial movement of the ball 4 due to

In the cage 5 shown in FIGS. 28 to 31, the ball insertion portion 68 is provided radially outward of the radial movement range of the ball 4. However, the ball insertion portion 68 is opposite to the ball 4. It may be provided radially inward of the radial movement range of Even when provided in this manner, the same effects as in the case where the ball insertion portion 68 is provided radially outward of the radial movement range of the ball 4 can be achieved.

  Next, in the cage 5 shown in FIGS. 32 and 33, the narrow portions 62A and 62B of the pocket 17 can be constituted by the radially inward raised portions 71 and 72 of the pocket 17 by plastic working. . One of the raised portions 71 is a circumferential inward portion provided at the axial end of the pocket 17 on the input shaft side, and the other raised portion 72 is provided at the axial end of the pocket 17 on the output shaft side It consists of a circumferential inner part.

  In this case, as shown in FIG. 33, plastic working is a so-called caulking that applies a pressing force in the arrow direction to the pocket peripheral edge on the input shaft side of the pocket 17 and the pocket peripheral edge on the output shaft side of the pocket 17 It is processing.

  Moreover, this pocket 17 is formed of an elongated hole radially extending in the radial direction centering on the axial center X1 of the rotating shaft 7 as in the case shown in FIGS. 6A and 6B and the like. Therefore, radial movement of the ball by engaging with the two ball engagement grooves is permitted. Moreover, the narrow portions 62A and 62B configured by the raised portions 71 and 72 can effectively prevent the ball 4 from coming off the pocket 17.

  Moreover, since the caulking process can be performed after the ball is inserted into the pocket 17, it is not necessary to configure the overlapping body 61 as in the case of the cage 5 shown in FIGS.

  Next, the cage 5 shown in FIGS. 34 and 35 is either the narrow portion 62A formed at one axial end of the pocket 17 or the narrow portion 62B formed at the other axial end. One is formed by a concave surface 63Aa, and the other is formed by a radially inward raised portion 72 of the pocket 17 by plastic working. That is, it has the pocket 17 of the shape which combined the pocket 17 shown in FIG. 27 grade | etc., And the pocket 17 shown in FIG. 32 grade | etc.,.

  For this reason, the incorporation of the ball 4 into the pocket 17 of the retainer 5 is, in this case, the side on which the raised portion 72 is formed (in this case, the opening is the ball) without the raised portion 72 being formed. The ball 4 is inserted from the outside diameter dimension Db of 4). Thereafter, the raised portion 72 is formed by caulking.

  Moreover, this pocket 17 is formed of an elongated hole radially extending in the radial direction centering on the axial center X1 of the rotating shaft 7 as in the case shown in FIGS. 6A and 6B and the like. Therefore, radial movement of the ball 4 by engaging with the second ball engagement groove 16 is permitted. In addition, the narrow portions 62A and 62B configured by the concave surface 63Aa and the protruding portion 72 can effectively prevent the ball 4 from coming off the pocket 17.

  In FIGS. 34 and 35, the narrow portion 62A of the axial end of the pocket 17 on the input shaft side is formed by the concave surface 63Aa, and the narrow portion 62B of the axial end of the pocket 17 on the output shaft side. However, the narrow portion 62A at the axial end of the pocket 17 on the input shaft side is constituted by the raised portion 71, and the width of the axial end of the pocket 17 on the output shaft side is The narrow portion 62B may be configured by a concave surface 63Ba.

  FIG. 36 is a perspective view of a reduction gear (before assembly) using the cage 5 having the pockets 17 as shown in FIGS. The assembling method in this case will be described. The process of FIG. 37 will be performed. First, "part subassembly" (step S1) → "assembly on the input side" (step S2) → "assembly of the cage assembly" (step S3) → "injection of lubricant" (step S4) → "output Assembling of the side (step S5) → "connection by bolt" (step S6) is performed.

  “Part subassembly” is a step of assembling the input shaft 7, the eccentric cam 8 and the bearing 9 to form the input shaft assembly, and a step of holding the ball 4 in the pocket 17 of the holder 5, In the case of the cage 5 as shown in FIGS. 25 to 27, after the ball 4 is interposed between the first member 60A and the second member 60B, the first member 60A and the second member 60 are made by using a rivet, welding, an adhesive or the like. This is a step of connecting the member 60B.

  Further, the assembly on the input side is a step of assembling the input side rotating member (input plate portion) 2 after assembling the input shaft assembly to the first member 6 a of the case 6. The assembly of the cage assembly includes the steps of assembling the cage assembly according to the first engagement groove 13 in the input plate portion 2 and inserting the fixing pin 19 for rotationally fixing the cage assembly. Process. The lubricant injection step is a step of applying a lubricant to the ball 4, the pocket 17 of the holder 5, and the groove (first engagement groove 13) of the input side rotation member (input plate portion) 2. The assembly on the output side is a step of assembling the output side rotation member (output plate portion) 3 into the second member 6 b of the case 6. The fastening of the bolt includes the step of inserting the fixing bolt 24 into the through hole (communication hole) 25 of the cage 5 and the second member 6b, and the fixing bolt 24 in the tap hole 26 of the first member 6a. It is a process of tightening.

  As described above, when the pocket 17 has the narrow portions 62A and 62B, the radial movement of the ball 4 by allowing engagement with the second ball engagement groove 16 is allowed, so that the efficiency does not deteriorate. 4 can be effectively prevented from falling out of the pocket 17 at this narrow portion. Therefore, at the time of transportation, in order to prevent the balls 4 from falling, the posture of the holder 5 is not taken care of, and the working efficiency can be improved.

  Further, the subassembly (step S1) of the ball 4 and the holder 5 is a so-called off-line before the assembly process (online) after this process. For this reason, the on-line worker can omit the detailed work of inserting the ball 4 into the plurality of pockets 17, and the worry of the mistake of putting the ball in place is eliminated. When the narrow portion of the pocket is formed by arcing the contact surface between the ball 4 and the cage 5, the contact surface pressure can be reduced by increasing the contact area, and the durability can be improved.

  On the other hand, when the pocket 17 does not have the narrow portions 62A and 62B, the inner peripheral surface (wall surface) of the elongated hole constituting the pocket 17 is a flat surface and the fitting is "slack fitting", In the assembly process, the ball 4 may fall out of the pocket 17 due to vibration or the like. For this reason, during transportation, etc., it is necessary to take a posture in which the ball 4 does not fall, and the transportation method is restricted. During transportation, etc., if the ball 4 falls, it is necessary to perform the work of incorporating the ball 4 again online, which may increase the number of work processes and may cause the ball 4 to fall during the incorporation work, It will be inferior in workability. In addition, it is also possible to change the fitting from "spacing blind" to "tight fitting". As described above, the drop of the ball 4 can be prevented by setting it as “tight fit”. However, if “tight fit” is used, the inner peripheral surface (wall surface) of the elongated hole (pocket 17) of the retainer 5 abuts on the ball 4, and the radial movement of the ball 4 is inhibited by the occurrence of friction. As a result, the transmission efficiency of the reduction gear may be degraded.

  The embodiment of the present invention has been described above, but the present invention can be variously modified without being limited to the above-described embodiment. In the reduction gear transmission of the first embodiment, the input plate portion 10 (10A, 10A, 10B) is configured to be rotatable with respect to the eccentric cam 8 provided on the rotating shaft 7, but the input plate portion 10 and the rotating shaft 7 may be integrated. Further, in the second reduction gear 1, the configuration in which the separate eccentric cam 8 is fitted to the rotation shaft 7 is exemplified, but the invention is not limited thereto, and the rotation shaft and the eccentric cam may be integrated. . Furthermore, the axis of the input plate 10 is the concentric axis of the rotary shaft 7 which is the input axis, and the center of curvature of the first ball engagement groove 13 is a predetermined amount with respect to the axis of the input plate 10. It may be eccentric. That is, the center of curvature to be formed may be formed with the ball engagement groove 13 eccentric to the axis of the rotation shaft 7 without providing the eccentric portion in the rotation shaft 7. For this reason, the degree of freedom of design is increased in a configuration in which the center of curvature of the first ball engagement groove 13 is eccentric with respect to the apparatus rotation center X by a predetermined amount, and the design of the apparatus can be improved. .

  In the reduction gear transmission 1 of the present embodiment, the reduction gear ratio i of -1/10 is exemplified. However, for example, the reduction gear ratio i may be appropriately set to about 1/5 to 1/20 as needed. In this case, the number of peak portions / valley portions of the wavelike curve of the track center line of the ball engagement groove, the number of pockets of the cage, and the number of balls may be appropriately set according to the reduction ratio i.

  When the ball engagement groove has a gothic arch shape, either the first ball engagement groove 13A or the second ball engagement groove 16A, or the first ball engagement groove 13B and the second ball It may be any of the engagement grooves 16B.

  In addition, as shown in FIG. 32, FIG. 33, FIG. 34, FIG. 35, etc., in the case of forming a narrow portion by a raised portion formed by plastic working, in the above embodiment, the entire narrow portion is formed by plastic working. It consisted of the ridges that were formed. However, in plastic working, a section (arbitrary part) which is not narrow is formed in part, the ball 4 is inserted through this section, and then this section also becomes narrow by caulking processing etc. You may form.

2 Input side rotation member (input plate part)
3 Output side rotation member (output plate part)
4 ball 7 rotation axis (input axis)
10, 10A, 10B Input plate portion 13, 13A, 13B First ball engagement groove 16, 16A, 16B Second ball engagement groove 17 Pocket 30, 30A, 30B Output plate portion 60A First member 60B Second member 61 Superimposed member 62, 62A, 62B Narrow part 63A, 63B Hole part 63Aa Concave surface 63Ba Concave surface 65 Concave arc surface 67 Body part 68 Ball insertion part 71, 72 Raised part

Claims (5)

An input side rotation member having an input plate portion in which a first ball engagement groove is formed, and an output plate portion arranged coaxially with the rotation axis of the input side rotation member and in which a second ball engagement groove is formed And a plurality of balls engaged with both ball engagement grooves of the axially opposed input plate portion and the output plate portion, and a plurality of balls for radially movably holding the balls. And a holder having a pocket, wherein the holder is provided non-rotatably with respect to the rotation shaft, and the rotation of the input side rotation member is decelerated via the balls engaged with the both ball engagement grooves. The reduction gear transmitted to the output side rotation member,
An orbital center line of the second ball engagement groove is formed by a wavy curve,
Assuming that the reduction gear ratio of the reduction gear is i, the wave-like curve is a state where the output side rotation member is at the rotation angle (iθ) at an arbitrary rotation angle (θ) of the input side rotation member. The ball engaged with the ball engaging groove of the second ball engaging groove, and the second ball engaging groove on both axial end sides of the pocket of the retainer A reduction gear provided with a narrow portion for permitting radial movement of a ball by engagement with the gear and restricting ball removal.   The cage includes an overlapping body of first and second members, and each of the first and second members is provided with a hole which constitutes the pocket when the first and second members are overlapped. The first member has a first concave surface for forming a narrow portion on the side of the input plate in the hole of the first member, and the hole on the second member has a narrow portion on the side of the output plate. The ball has a gap in each pocket by forming a superposed body in a state of having the second concave surface and interposing the ball inserted in each pocket between the first and second members. The reduction gear according to claim 1, wherein the reduction gear is inserted in a state.   The pocket of the cage is radially outward or diameter-wise more than the radial movement range of the ball by engaging the second ball engagement groove with the main body portion having the narrow portion constituted by the concave curved surface The reduction gear according to claim 1, further comprising: a ball insertion portion provided inward in the direction.   2. The reduction gear according to claim 1, wherein a part or all of the narrow part of the pocket of the cage is formed by a radially inward protrusion of the pocket formed by plastic working.   Either the narrow portion formed at one axial end of the pocket of the cage or the narrow portion formed at the other axial end is formed as a concave surface, and a part of the other or The reduction gear according to claim 1, characterized in that the whole is constituted by a radially inward raised portion of the pocket formed by plastic working.

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