JP2005188740A - Reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduction gear of simple constitution with high driving efficiency and torque output and moreover with a long service life at a low cost. <P>SOLUTION: This reduction gear is provided with a circular spline 1 and an input side housing 8 formed with internal teeth 1a, 8a; a flex spline 2 formed with external teeth 2a equal in module to the internal teeth 8a and less in the number of teeth than the internal teeth 8a and having flexibility; and a wave generator 3 fitted to the inside of the flex spline 2 to bend the flex spline 2 into approximately elliptic shape and engaging the circular spline 1 and input side housing 8 with the flex spline at two major axis parts. An input shaft 7 integrated with the wave generator 3, and the circular spline 1 with which an output shaft 4 is integrated, are supported/linked with each other by bearings 15. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a reduction gear using a flexure meshing gear device.

  Conventionally, a flexure meshing gear device called a so-called harmonic drive mechanism is known. A typical harmonic drive mechanism includes a rigid circular internal gear (circular spline) and an internal gear that is provided inside the internal gear and is deformed into an elliptical shape so as to mesh with the gear at two locations. 2n (n is a positive integer) less than the number of teeth of the flexible external gear (flex spline) set to the number of teeth and the inside of the external gear and the external gear is elliptical It consists of a wave generator that bends.

  The wave generator is composed of an inner elliptical cam plate and a ball bearing that is fitted into the outer periphery of the cam plate and deformed and bent into an elliptical shape. The outer ring of the wave generator bearing is fitted to the external gear. Match. The harmonic drive mechanism having such a configuration is a so-called differential type speed reducer. When the input shaft provided in the wave generator is rotated, the elliptical shape of the external gear is rotated, and this elliptical rotation Thus, when both gears rotate relative to each other according to the difference in the number of teeth and an output shaft is provided on the internal gear or the external gear, the output shaft rotates at a large reduction ratio with respect to the input shaft.

  However, the above-described wave generator requires a special flexible ball bearing on the outer periphery of the elliptical cam plate in order to improve driving efficiency, which makes the entire apparatus expensive. Therefore, a wave generator has been proposed for providing a harmonic drive mechanism that is inexpensive and surely performs a proper operation for a long time (see, for example, Patent Document 1).

  Specifically, the rotating plate can rotate inside the external gear, and can be rotated on the rotating plate and mounted on the elliptical long axis or in the vicinity of the diametrical direction. A pair of first rollers, and two pairs of second rollers that are rotatably mounted at positions close to both sides of each first roller and facing each other in the diametrical direction, and are loaded Even so, the three pairs of rollers are used to maintain the shape of the major axis of the external gear and the vicinity thereof in an elliptical outline.

  Moreover, what implement | achieves the reduction gear which can arrange | position an input shaft and an output shaft coaxially at low cost is disclosed (for example, refer patent document 2). Specifically, a bearing is interposed between the center part of the arm of the planetary gear mechanism and the extension part of the output shaft, and a plurality of rotatable rollers are arranged on the outer periphery of the arm, and this is used as a wave generator. It is set as the structure which serves as both. As a result, the arm of the planetary gear mechanism and the wave generator of the harmonic drive mechanism are integrated with a simple structure, and a high-reduction ratio and high-efficiency reduction device using a highly reliable and accurate wave generator is inexpensive. It can be realized.

Japanese Utility Model Publication No. 63-125247 JP-A-4-244636

  In the configuration described in each of the above-mentioned patent documents, as a means for maintaining the elliptical shape of the wave generator, which is a condition for obtaining a stable turning operation of the wave generator, both are in the vicinity of the main roller or substantially at right angles. A so-called auxiliary roller is provided along the short axis portion. This is because the elliptical shape of the wave generator is not stably maintained with only the small-diameter main roller, and the flex spline and the circular spline do not transition from the semi-engaged state to the normal engaged state in sequence. It is.

  However, in such a configuration using the main roller and the auxiliary roller, in order to maintain the shape of the long axis of the flex spline and the vicinity thereof in an elliptical outline, each roller must be arranged with high accuracy. . If the positional accuracy of each roller or the dimensional accuracy of the flex spline varies, the flex spline will bend before and after the main roller during the turning operation of the wave generator. This shows a state in which the front and rear teeth are released in the radial direction, and the engagement becomes unstable and the tooth engagement sound is generated. In particular, when the rotation speed of the wave generator changes abruptly, a strong tensile stress is applied to the flex spline, and in the worst case, there is a possibility that a so-called instantaneous interruption occurs in which the flex spline is instantaneously cut.

  In addition to the configuration using the main roller and the auxiliary roller, the conventional general harmonic drive mechanism has a configuration in which the input shaft and the output shaft are completely separated via a wave generator. In the case where the input shaft and the output shaft are arranged coaxially as in Patent Document 2, it is difficult to maintain the center position accuracy of the input and output shafts with high accuracy, and the rotation operation is performed smoothly. There was also a problem that the drive efficiency could not be sufficiently increased due to the absence of the drive.

  In order to provide a lightweight and inexpensive reduction gear, it is conceivable that each member constituting the reduction gear is formed of a resin material. However, since the resin material has lower thermal conductivity than a metal material, friction during driving is considered. The life is shortened due to a decrease in material strength, frictional force, increased wear, etc. due to heat generated by. For this reason, some measures are required when an operation in which the load torque acts continuously for a long time is required.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a reduction gear with a simple configuration, high drive efficiency and high torque output, and a long service life at low cost.

In order to achieve the above object, the speed reducer of the present invention is configured as follows.
(1) a circular spline formed with internal teeth, an input-side housing, a flex spline having a module in which the internal teeth of the input-side housing are the same as the internal teeth and having a small number of teeth, and having flexibility; A speed reducer comprising a wave generator that is fitted inside a flex spline, flexes the flex spline into a substantially elliptical shape, and engages both the internal teeth and the flex spline at two locations of the long axis portion. The input shaft integrated with the generator and the circular spline integrated with the output shaft are mutually supported and connected by a bearing.

(2) a circular spline formed with internal teeth, an input side housing, a flex spline having a module in which the internal teeth of the input side housing are equal to the internal teeth and having a small number of teeth, and having flexibility; A speed reducer comprising a wave generator that is fitted inside a flex spline, flexes the flex spline into a substantially elliptical shape, and engages both the internal teeth and the flex spline at two locations of the long axis portion. The center of the roller incorporated in the generator and rolling on the inner peripheral surface of the flex spline and the center of the roller shaft are made eccentric.

(3) a circular spline in which internal teeth are formed, a flex spline in which the internal teeth and the module are equal and the number of teeth is small, yet flexible, and the flexible spline is fitted inside the flex spline. And a wave reducer having a wave generator that bends the flex spline into a substantially elliptical shape and engages the two splines at two locations of the long axis portion thereof, extending from the wave generator, and having a tip at the inner periphery of the flex spline. A tensioner that is slidably pressed on the surface is provided, and the tension of the flex spline is adjusted by adjusting the length of the tensioner.

(4) In the speed reducer of (3), a plurality of rolling elements that roll while pressing the inner peripheral surface of the flex spline are disposed at the tip of the wave generator.

(5) In the reduction gear of (3) or (4), a plurality of rolling elements that roll while pressing the inner peripheral surface of the flex spline are disposed at the tip of the tensioner.

(6) In the reduction gear of (3), (4) or (5), the length of the wave generator is adjusted to adjust the distance between the circular spline and the flex spline. Features.

(7) a circular spline in which internal teeth are formed, an external tooth in which the internal teeth and the module are equal and the number of teeth is small, and a flexible spline that is flexible, and is fitted inside the flex spline. And a wave reducer provided with a wave generator that engages the two splines at two locations on the long axis portion thereof by bending the flex spline into a substantially elliptical shape, extending inward from the flex spline and opening the output shaft. A shaft slidably fitted in the hole is provided, and torque from the flex spline is transmitted to the output shaft by the shaft.

In the reduction gear of (8), (1), (2), (3), (4), (5), (6) or (7), each member constituting the reduction gear is mainly formed of a resin material. It is characterized by that.

(9) a circular spline in which internal teeth are formed, an external tooth having the same number of teeth as the internal teeth and a module, and a flexible spline that is still flexible; and a flexible spline that fits inside the flex spline. In the speed reducer provided with a wave generator that bends the flex spline into a substantially oval shape and engages the two splines at two locations on its long axis portion, each member constituting the speed reducer is mainly formed of a resin material. Reducer characterized by that.

(10) In the speed reducer of (8) or (9), a groove extending in the axial direction of the roller is provided on the outer peripheral surface of the resin roller that is incorporated in the wave generator and rolls on the inner peripheral surface of the flex spline. A plurality of them are formed at predetermined intervals.

In the reducer according to (11), (8), (9) or (10), the shape of the resin roller incorporated in the wave generator and rolling on the inner peripheral surface of the flex spline is centered from the end of the roller. The diameter of the part is reduced.

(12), (8), (9), (10) or (11), characterized in that a sleeve made of a metal material is fitted to the inner peripheral surface of the flex spline.

(13), (8), (9), (10), (11) or (12), characterized in that a plurality of slits are formed at least in the circumferential direction of the external teeth of the flexspline. .

(14), (8), (9), (10) or (11), wherein the flex spline is formed of a metal material.

According to the invention of (1), since the center position system of the input and output shafts can be maintained with high accuracy, the rotational operation becomes smooth and the driving efficiency is improved.

According to the invention of (2), the pressing amount of the roller against the flex spline can be adjusted by changing the mounting angle of the roller shaft, and the meshing of the teeth can be optimized. Improvement of life due to improvement and optimization of tooth surface pressure can be achieved.

According to the invention of (3), an appropriate tension is applied to the flex spline, the flex spline is prevented from being bent during the turning operation of the wave generator, so-called instantaneous interruption is prevented, and the life can be improved. In addition, since it is suppressed that the teeth before and after being pressed by the wave generator are released in the radial direction, the number of meshing teeth between the outer teeth of the flex spline and the inner teeth of the circular spline can be increased. The load on each tooth is reduced, and a long life and high output torque are obtained.

According to the invention of (4), the friction with the flex spline can be reduced, and the driving efficiency can be improved at low cost.

According to the invention of (5), friction with the flex spline can be reduced, torque loss due to sliding can be reduced, and driving efficiency can be further improved.

According to the invention of (6), the number of meshing teeth between the external teeth of the flex spline and the internal teeth of the circular spline can be increased, and backlash can be reduced, higher torque transmission, and longer life can be realized.

According to the invention of (7), fatigue breakage can be prevented by transmitting torque to the output shaft while absorbing deformation strain on the output shaft side when the flex spline is deformed into a substantially elliptical shape.

According to the invention of (8), a reduction gear having desired performance can be provided at a light weight and at a low cost.

According to the invention of (9), it is possible to provide a reduction gear using a flexure meshing gear device that is lightweight and inexpensive.

According to the invention of (10), since a gap is formed between the flex spline and the resin roller, the heat dissipation is improved, and since the lubricant flows into the groove, the cooling performance is improved and continuous operation for a long time is possible. become.

According to the invention of (11), when the resin roller expands due to heat generated during operation, the diameter of the end portion and the center portion become the same, and the entire roller width comes into contact with each other. Since the surface pressure acting on the surface can be reduced, the service life is improved.

According to the invention of (12), the heat generated in the flex spline is dissipated through the sleeve made of a metal material having high heat conductivity, so that the heat dissipating property is improved and a continuous operation for a long time becomes possible. In addition, the fatigue strength of the flex spline is improved, leading to an improvement in life.

According to the invention of (13), the heat dissipation is improved by the slit and the lubricity is improved by the inflow of the lubricant into the slit portion, so that the temperature rise of the teeth can be suppressed, the material strength drop due to the temperature rise is prevented, the friction, Wear can be reduced, leading to improved life.

According to the invention of (14), the heat generated in each member is dissipated through the flex spline made of a metal material having high heat conductivity, so that the heat dissipating property is improved, and continuous operation for a long time becomes possible.

  Hereinafter, a reduction gear according to the present invention will be described in detail with reference to the accompanying drawings.

  1 is a cross-sectional view of a reduction gear according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG.

  As shown in the figure, the speed reducer of this embodiment forms a circular spline (internal gear) 1 having an internal tooth 1a, and an external tooth 2a having the same module as the internal tooth 1a and the same number of teeth. A flexible spline (external gear) 2 having flexibility and 2n (n is a positive integer) number of teeth of the external teeth 2a of the flexspline 2 are formed, for example, two internal teeth 8a that are set to be two more. The input side housing 8 and the inside of the flex spline 2 are fitted into the flex spline 2 so that the flex spline 2 is bent into a substantially elliptical shape. A so-called harmonic drive mechanism including a wave generator 3 for engaging the.

  An output shaft 4 is integrally formed at the center of the circular spline 1 and is rotatably supported by the output housing 5 by a pair of left and right bearings 6a and 6b. An input shaft 7 is integrally assembled with the wave generator 3 and is rotatably supported by a bearing 9 on an input side housing 8. The output shaft 4 and the input shaft 7 are arranged coaxially in the housings 5 and 8.

  In the wave generator 3, a pair of main rollers 10 are positioned between a pair of left and right circular support plates 11 formed integrally with the input shaft 7 at a point-symmetrical position orthogonal to the axis of the input shaft 7. The roller shaft 12 installed between the support plates 11 is rotatably supported via a pair of left and right bearings 13, and the main roller 10 presses two points on the inner side of the flex spline 2. The inner teeth 1a, 8a and the outer teeth 2a are engaged with each other, the pressing point is moved following the rotation of the wave generator 3 on the input side, and the flex spline 2 is rotated to rotate the output shaft 4 integral with the circular spline 1 as described above. The reduced rotation is performed at a reduction ratio determined by the difference in the number of teeth between the inner teeth 8a and the outer teeth 2a.

  A pair of auxiliary rollers 14 are rotatably supported between the circular support plates 11 with the same configuration as the main roller 10 with a phase difference of about 90 ° from the main roller 10. The elliptical shape of the flex spline 2 is stably maintained by the auxiliary roller 14 so that the flex spline 2 and the circular spline 1 can sequentially and stably transition from the semi-engaged state to the normal engaged state. It has become.

  In this embodiment, one end (the left end in the figure) of the input shaft 7 is fitted into one end of the output shaft 4 (the right end in the figure: the central portion of the circular spline 1). It is supported and linked in a freely rotatable manner.

  In this way, in this embodiment, the auxiliary roller 14 applies appropriate tension to the flex spline 2 to suppress flexure of the flex spline 2 during the turning operation of the wave generator 3, thereby preventing so-called instantaneous interruption and improving the life. I am letting. Further, since the front and rear teeth pressed by the main roller 10 are also prevented from being released in the radial direction, the outer teeth 2a of the flex spline 2, the inner teeth 1a of the circular spline 1, and the input side housing 8 The number of teeth meshing with the teeth 8a can be increased, the load on each tooth is reduced, and a long life or high output torque is obtained.

  In addition, the input shaft 7 and the output shaft 4 arranged on the same axis are supported and connected to each other via a bearing 15 so that they can rotate relative to each other. Since the center position system of the output shafts 7 and 4 can be maintained with high accuracy, the rotational operation becomes smooth and the driving efficiency is improved. In other words, the so-called plowing motion that occurs when the input shaft 7 is cantilevered is avoided.

  As a result, each member constituting the speed reducer (circular spline 1 and output shaft 4, flex spline 2, main roller 10, auxiliary roller 14, input shaft 7 and circular support plate 11, output side housing 5, input side housing 8 Etc.) is made of a resin material instead of a metal material, a decrease in material strength, an increase in frictional force and wear due to heat generated by friction during driving are suppressed, and load torque acts continuously for a long time. Driving is also possible. In this case, at least only the flex spline 2 may be formed of a metal material. According to this, heat generated in each member is dissipated through the flex spline 2 made of a metal material having high thermal conductivity, heat dissipation is improved, and continuous operation for a long time is possible. Of course, even if most of the members constituting the speed reducer are made of a metal material, the above-described effects can be naturally obtained.

  FIG. 3 is a front view of the roller of the speed reducer according to the second embodiment of the present invention (FIG. 3A) and a sectional view around the roller (FIG. 3B).

  In the first embodiment, when each member constituting the speed reducer is formed of a resin material, a groove 16 extending in the roller axial direction is predetermined in the circumferential direction on the outer circumferential surface of the main roller 10 (and the auxiliary roller 14). This is an example in which a plurality are formed at intervals.

  According to this, since a gap is formed between the flex spline 2 and the main roller 10 (and the auxiliary roller 14), the heat dissipation is improved, and since the lubricant flows into the groove 16, the cooling performance is improved, and the long time. Can be operated continuously.

  FIG. 4 is a cross-sectional view around the roller of the speed reducer according to the third embodiment of the present invention.

  This is an example in which the diameter of the central portion of the main roller 10 (and auxiliary roller 14) is made smaller than the end portion of the roller when each member constituting the speed reducer is formed of a resin material in the first embodiment. It is.

  According to this, when the main roller 10 (and the auxiliary roller 14) expands due to heat generated during operation, the diameter of the end portion and the center portion become the same, and the entire roller width comes into contact with each other, so that the tooth engagement rate is improved In addition, since the surface pressure acting on the teeth can be reduced, the life is improved. This is because the temperature gradient due to heat generation during operation is higher in the central portion than in the roller end portion, so that the problem due to an increase in the expansion amount in the central portion is solved.

  FIG. 5 is a front view of a flex spline of a reduction gear according to a fourth embodiment of the present invention.

  In the first embodiment, when each member constituting the speed reducer is formed of a resin material, the metal sleeve 17 is fitted to the inner peripheral surface of the flex spline 2 so as not to be relatively rotatable by an appropriate fitting means or the like. This is an example.

  According to this, the heat generated in the flex spline 2 is dissipated through the metal sleeve 17 having high thermal conductivity, the heat dissipation is improved, and a continuous operation for a long time is possible. Further, the fatigue strength of the flex spline 2 is improved, leading to an improvement in life.

  FIG. 6 is a perspective view of main parts of a flex spline of a reduction gear according to a fifth embodiment of the present invention.

  This is because the external teeth 2a of the flex spline 2 (and the internal teeth 1a of the circular spline 1 and the internal teeth 8a of the input side housing 8) are formed in the first embodiment when each member constituting the speed reducer is formed of a resin material. This is an example in which a plurality of slits 18 are formed in the circumferential direction. The depth of the slit 18 may not reach the tooth base of the external tooth 2a (and the internal teeth 1a, 8a).

  According to this, since the heat dissipation is improved by the slit 18 and the lubricity is improved by the inflow of the lubricant into the slit 18 portion, the temperature rise of the external teeth 2a (and the internal teeth 1a and 8a) can be suppressed, and the temperature rise Prevents material strength from decreasing and reduces friction and wear, leading to improved life.

  FIG. 7 is a front view (FIG. 7A) of a roller of a reduction gear according to a sixth embodiment of the present invention and a sectional view around the roller (FIG. 7B).

This is because the inner peripheral surface of the flex spline 2 is incorporated into the wave generator 3 (see FIG. 1) regardless of whether each member constituting the speed reducer is a metal material or a resin material in the first embodiment. an example in which decentering the center of the main roller 10 that rolls the center of the (roller center C ₁ reference) and the roller shaft 12 (see the roller shaft center C _2).

  According to this, by changing the mounting angle of the roller shaft 12, it is possible to adjust the pressing amount of the main roller 10 to the flex spline 2, and to optimize the meshing of the teeth. Improvement of life due to improvement and optimization of tooth surface pressure can be achieved. Needless to say, this embodiment may be applied to the auxiliary roller 14 (see FIG. 2) so that the tension of the flex spline 2 can be adjusted.

  FIG. 8 is a diagram schematically illustrating the configuration of a reduction gear according to a seventh embodiment of the present invention. FIG. 8A is a longitudinal sectional view, and FIGS. FIG. The speed reducer of the present invention uses a so-called harmonic drive mechanism, and as shown in the figure, a cup-shaped flex spline 2 connected to an output shaft 4 is fitted to a fixed ring-shaped circular spline 1. The wave generator 3 connected to the input shaft 7 is included in the flex spline 2.

  On the outer periphery of the flex spline 2, external teeth 2a for torque transmission are formed. On the other hand, an inner tooth 1 a that meshes with the outer tooth 2 a of the flex spline 2 is formed on the inner periphery of the circular spline 1. The number of external teeth 2a of the flex spline 2 is 2n (n is a positive integer), for example, 2 less than the number of internal teeth 1a of the circular spline 1.

  Further, the wave generator 3 existing inside the flex spline 2 is composed of a support 11a having a pair of main rollers 10 at a point-symmetrical position orthogonal to the axis of the input shaft 4 in the case of FIG. Two points on the inner side of the flex spline 2 are pressed by the roller 10, the inner teeth 1a and the outer teeth 2a are meshed at the pressing point, the pressing point is moved by following the rotation of the wave generator 3 on the input side, and the flex spline is moved. 2 is rotated so that the output shaft 4 is decelerated and rotated at a reduction ratio determined by the difference in the number of teeth between the internal teeth 1a and the external teeth 2a.

  The tensioner 20 extends in the radial direction from the center of the support 11a so as to be substantially orthogonal to the axis of the input shaft 7 and the support 11a. Fan-shaped portions 20a are provided at both ends of the tensioner 20, and each of the outer peripheral surfaces slides along a short axis of the flex spline 2 and a substantially elliptical inner peripheral surface formed in the vicinity thereof. Pressed as possible. Each fan-shaped portion 20a can be expanded and contracted in the radial direction by a screw mechanism or the like (not shown), thereby adjusting the length of the tensioner 20 and thus adjusting the tension of the flex spline 2 to be fixed. ing.

  In this way, an appropriate tension is applied to the flex spline 2 to suppress flexure of the flex spline 2 during the turning operation of the wave generator 3, thereby preventing so-called instantaneous interruption and improving the life. Further, at this time, since the teeth before and after being pressed by the main roller 10 are also prevented from being released in the radial direction, the number of meshing teeth between the external teeth 2a of the flex spline 2 and the internal teeth 1a of the circular spline 1 is suppressed. The load on each tooth is reduced, and a long life or high output torque is obtained.

  In FIG. 2C, a bearing 21 is provided instead of the main roller 10. The bearing 21 is configured as a ball bearing, a roller bearing, or a needle bearing, thereby further reducing friction with the flex spline 2 and improving driving efficiency at a low cost. A so-called cam follower may be used instead of the bearing 21.

  In FIG. 4D, a fan-shaped portion 22 is provided in place of the main roller 10, and a plurality of rolling elements 23, that is, rotatable balls, rollers, needles, or the like are arranged along the outer peripheral surface. Yes. And it is set as the structure which rolls by pressing the inner peripheral surface of the flex spline 2 by these. Thereby, friction with the flex spline 2 is reduced, and driving efficiency is improved at low cost.

  The outer peripheral surface of the fan-shaped portion 22 has a radius of curvature larger than that of the main roller 10 and the bearing 21. Specifically, the shape is formed along a substantially elliptical outline formed near the major axis of the flex spline 2 and the vicinity thereof, or further, a shape along or close to the circular outline of the circular spline 1. . As a result, the number of meshing teeth between the outer teeth 2a of the flex spline 2 and the inner teeth 1a of the circular spline 1 can be increased, the load on each tooth is reduced, and a long life or high output torque is obtained.

  FIG. 9 is a diagram schematically showing a configuration of a reduction gear according to an eighth embodiment of the present invention, where FIG. 9A is a longitudinal sectional view, and FIGS. 9B to 9D are cross sections of the respective configuration examples. FIG. In the present embodiment, a plurality of rolling elements 23, that is, rotatable balls, rollers, needles, or the like are arranged along the outer peripheral surface of the fan-shaped portion 20a of the tensioner 20. And it is set as the structure which rolls by pressing the inner peripheral surface of the flex spline 2 by these. Thereby, friction with the flex spline 2 is reduced, torque loss due to sliding is reduced, and driving efficiency is further improved.

  FIG. 10 is a diagram schematically showing the configuration of the reduction gear according to the ninth embodiment of the present invention. FIGS. 10A and 10C are cross-sectional views of the respective configuration examples, and FIG. (D) is an enlarged longitudinal sectional view of a main part of each. In this embodiment, the distance between the circular spline 1 and the flex spline 2 is adjusted by adjusting the lengths of the support 11a and the tensioner 20. As a result, the number of meshing teeth between the external teeth 2a of the flex spline 2 and the internal teeth 1a of the circular spline 1 can be increased, and a reduction in backlash, higher torque transmission, and a longer life can be realized.

  Specifically, for example, as shown in FIGS. 4A and 4B, a tapered screw 26 is provided through the hole 25 near the center of the support 11a and the long hole 24 at the inner end of the tensioner 20, By rotating and inserting and removing the tensioner 20, the distance between the circular spline 1 and the flexspline 2 is adjusted by sliding the tensioner 20 along the side surface of the tapered screw 26 as indicated by the arrow and adjusting the length thereof. Finally, for example, adhesive fixing is performed. This is the same when the length of the support 11a is adjusted.

  Alternatively, for example, as shown in FIGS. 3C and 3D, a wedge 27 is provided between the center portion of the support 11a and the tensioner 20, and this is sandwiched by ring-shaped plates 28 from both sides in the axial direction. By tightening or loosening them with bolts 29 and nuts 30 and inserting and removing the wedge 27, the tensioner 20 is slid along the slope of the wedge 27 as shown by the arrow to adjust its length. 1. Adjust the distance between the flex splines 2. Finally, for example, adhesive fixing is performed.

  This is the same when the length of the support 11a is adjusted. A bolt 29 passes through the long hole 24 at the inner end of the tensioner 20. Further, by varying the slope of each wedge 27, the degree of adjustment of the distance between the circular spline 1 and the flex spline 2 can be made different. For example, by adjusting the length of the support 11a as a fine adjustment and using the length adjustment of the tensioner 20 as a coarse adjustment, the adjustment can be performed accurately and quickly.

  FIG. 11 is a diagram schematically illustrating the configuration of a speed reducer according to a tenth embodiment of the present invention, where FIG. 11 (a) is a longitudinal sectional view and FIG. 11 (b) is a transverse sectional view. In the present embodiment, the flex spline 2 is formed in a substantially cylindrical shape instead of a cup shape, and a plurality of radial shafts 31 extending radially inward from the inner periphery of the output shaft side end portion are provided. This may be a columnar shape, a plate shape, or other shapes as long as the torque transmission is strong. The large-diameter portion 4a of the output shaft 4 is formed in the circular spline 1, and a slide hole 4b that is perpendicular to the axial center of the output shaft 4 is formed in the radial spline 1 so that the shaft 31 is fitted therein. It has become. The shaft 31 is slidable in the radial direction in the slide hole 4b, thereby constituting a slide mechanism.

  Now, the flex spline 2 rotates while the outer teeth 2a mesh with the inner teeth 1a of the circular spline 1 while the cross section thereof is deformed into a substantially elliptical shape. At this time, if the flex spline 2 has a conventional cup shape, a stress concentration portion is generated at the root portion, which may cause fatigue fracture. Therefore, by providing a slide mechanism as in this embodiment and transmitting torque to the output shaft 4 while absorbing the deformation strain on the output shaft side when the flex spline 2 is deformed into a substantially elliptical shape, fatigue fracture is caused. It is preventing.

  Further, as described above, by providing the slide hole 4b in the large-diameter portion 4a of the output shaft 4, the fitting length L between the slide hole 4b and the shaft 31 can be increased, and thereby the circumferential direction can be increased. The backlash is reduced. Further, by providing a linear motion bearing at the fitting portion between the slide hole 4b and the shaft 31, sliding friction can be reduced and driving efficiency can be increased.

  In addition, in this embodiment, as shown in FIG. 4B, the slide hole 4b has four cross holes and is in a cross shape. However, the present invention is not limited to this, and the number and arrangement are arbitrary as required. Set to In addition, by disposing each slide hole 4b in the axial direction of the output shaft 4, each slide hole 4b can be lengthened, and thus the fitting length L between the slide hole 4b and the shaft 31 can be increased. As a result, the play in the circumferential direction can be further reduced.

  In the seventh to tenth embodiments described above, each member constituting the speed reducer can be mainly formed of a resin material. Examples of the resin material include, for example, engineering plastics such as polyacetal, polyether ether ketone, polycarbonate, or polyamide-based material having excellent heat resistance, friction resistance, and wear resistance. In addition, nylon-based materials are also promising as general-purpose plastics. Since these resin materials are not machined at all and can be assembled with high precision by the above-described adjusting mechanisms and the like, a reduction gear having desired performance can be provided at a light weight and at a low cost.

It is sectional drawing of the reduction gear which concerns on Example 1 of this invention. It is the II-II sectional view taken on the line of FIG. It is the front (the figure (a)) of the roller of the reduction gear which concerns on Example 2 of this invention, and sectional drawing (the figure (b)) around a roller. It is sectional drawing of the roller periphery of the reduction gear which concerns on Example 3 of this invention. It is a front view of the flex spline of the reduction gear which concerns on Example 4 of this invention. It is a principal part perspective view of the flex spline of the reduction gear which concerns on Example 5 of this invention. It is the front (the figure (a)) of the roller of the reduction gear which concerns on Example 6 of this invention, and sectional drawing (the figure (b)) around a roller. It is a figure which shows typically the structure of the reduction gear which concerns on Example 7 of this invention. It is a figure which shows typically the structure of the reduction gear which concerns on Example 8 of this invention. It is a figure which shows typically the structure of the reduction gear which concerns on Example 9 of this invention. It is a figure which shows typically the structure of the speed reducer which concerns on Example 10 of this invention.

Explanation of symbols

  1 Circular spline, 1a internal tooth, 2 flex spline, 2a external tooth, 3 wave generator, 4 output shaft, 4a large diameter, 4b slide hole, 5 output housing, 6a, 6b bearing, 7 input shaft, 8 input side Housing, 8a Internal tooth, 9 Bearing, 10 Main roller, 11 Circular support plate, 11a Support, 12 Roller shaft, 13 Bearing, 14 Auxiliary roller, 15 Bearing, 16 Groove, 17 Metal sleeve, 18 Slit, 20 Tensioner, 20a Fan-shaped part, 21 Bearing, 22 Fan-shaped part, 23 Rolling element, 24 Long hole, 25 hole, 26 Tapered screw, 27 Wedge, 28 Plate, 29 Bolt, 30, Nut, 31 Shaft.

Claims (14)

  A circular spline having internal teeth, an input side housing, a flex spline having a module in which the internal teeth of the input side housing are equal to the internal teeth and having a small number of teeth, and having flexibility, and the inside of the flex spline And a wave reducer comprising a wave generator that bends the flex spline into a substantially elliptical shape and engages the inner spur and the flex spline at two locations on its long axis portion, and is integrated with the wave generator. A speed reducer, wherein the input shaft and the circular spline with which the output shaft is integrated are supported and connected to each other by a bearing.   A circular spline having internal teeth, an input side housing, a flex spline having a module in which the internal teeth of the input side housing are equal to the internal teeth and having a small number of teeth, and having flexibility, and the inside of the flex spline And a wave generator for bending the flex spline into a substantially elliptical shape and engaging the both internal teeth and the flex spline at two locations on the long axis portion thereof. And a center of a roller that rolls on the inner peripheral surface of the flex spline and a center of the roller shaft are decentered.   A circular spline having internal teeth, an external tooth having the same number of teeth as the internal teeth and a module, and a flexible spline, and a flexible spline fitted inside the flex spline. The wave reducer includes a wave generator that engages the two splines at two locations on the long axis portion thereof and extends from the wave generator, and the tip slides on the inner peripheral surface of the flex spline. A speed reducer comprising a tensioner that can be pressed, and adjusting the tension of the flex spline by adjusting the length of the tensioner.   4. The speed reducer according to claim 3, wherein a plurality of rolling elements that roll while pressing an inner peripheral surface of the flex spline are disposed at a tip of the wave generator.   5. The speed reducer according to claim 3, wherein a plurality of rolling elements that roll while pressing an inner peripheral surface of the flex spline are disposed at a tip of the tensioner. 6.   The speed reducer according to claim 3, 4 or 5, wherein the distance between the circular spline and the flex spline is adjusted by adjusting a length of the wave generator.   A circular spline having internal teeth, an external tooth having the same number of teeth as the internal teeth and a module, and a flexible spline, and a flexible spline fitted inside the flex spline. In a reducer equipped with a wave generator that engages the two splines at two locations on its long axis by bending it into an elliptical shape, it extends inward from the flex spline and can slide into a hole drilled in the output shaft A speed reducer comprising: a shaft fitted to the shaft, and transmitting torque from the flex spline to the output shaft through the shaft.   The speed reducer according to claim 1, 2, 3, 4, 5, 6 or 7, wherein each member constituting the speed reducer is formed mainly of a resin material.   A circular spline having internal teeth, an external tooth having the same number of teeth as the internal teeth and a module, and a flexible spline, and a flexible spline fitted inside the flex spline. And a wave generator that engages the two splines at two locations of the long axis portion thereof, each member constituting the reducer is mainly formed of a resin material. And reducer.   The speed reducer according to claim 8 or 9, wherein a groove extending in the roller axial direction is spaced apart from the outer peripheral surface of a resin roller incorporated in the wave generator and rolling on the inner peripheral surface of the flex spline by a predetermined interval in the circumferential direction. A speed reducer characterized in that a plurality of speed reducers are formed.   The speed reducer according to claim 8, 9 or 10, wherein the diameter of the central portion of the resin roller incorporated in the wave generator and rolling on the inner peripheral surface of the flex spline is made smaller than the end of the roller. Reducer characterized by.   12. The reduction gear according to claim 8, wherein a sleeve made of a metal material is fitted to an inner peripheral surface of the flex spline.   13. The reduction gear according to claim 8, wherein a plurality of slits are formed at least in the circumferential direction of the external teeth of the flex spline.   The speed reducer according to claim 8, 9, 10, or 11, wherein the flex spline is formed of a metal material.

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