JP2019078314A - Eccentric oscillation type reduction gear - Google Patents

Abstract

To provide an eccentric oscillation type reduction gear capable of sufficiently creating the lubricant coat on the outer pin.SOLUTION: An internal gear includes: an internal gear body (26A); a pin groove (26C) provided in the internal gear body; and an outer pin (26B) rotatably disposed in the pin groove. The pin groove (26C) includes: a first recess (261) that is provided radially outward of a first external gear (22) and is not in contact with the outer pin; a second recess (262) that is provided radially outward of a second external gear (24) and is not in contact with the outer pin; and a contact part (263) that is provided between the first recess and the second recess and in contact with the outer pin. Facing edge faces (221, 241) of the first external gear and the second external gear are located radially inward of the contact part (263), and at outer peripheral corner part of the edge faces (221, 241) facing each other, there are provided roll off parts (222, 242) that escape radially inward from the portions of the external gear and the second external gear that come into contact with the outer pins.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an eccentric oscillation type reduction gear.

  In FIG. 1 of Patent Document 1, an eccentricity in which the internal gear, the first external gear and the second external gear meshing with the internal gear, and the first external gear and the second external gear are eccentrically rocked. An eccentric rocking type reduction gear comprising a body is shown. The internal gear includes an internal gear main body, a pin groove provided in the internal gear main body, and an outer pin rotatably disposed in the pin groove.

JP, 2013-124730, A

  If a coating of a lubricant can be formed on the sliding surface of a machine component, the effect of improving the durability of the sliding surface is obtained. However, in the eccentric rocking type reduction gear as shown in Patent Document 1, there is a problem that the lubricant coating is not sufficiently formed on the outer pin due to the slip between the outer pin and the pin groove.

  An object of the present invention is to provide an eccentric rocking type reduction gear capable of sufficiently forming a coating of a lubricant on an outer pin.

The present invention relates to an eccentric shaft for eccentrically rocking an internal gear, a first external gear and a second external gear meshing with the internal gear, and a first external gear and the second external gear. An eccentric rocking type reduction gear comprising:
The internal gear includes an internal gear main body, a pin groove provided in the internal gear main body, and an outer pin rotatably disposed in the pin groove.
The pin groove is provided at a radially outer side of the first external gear and does not contact the outer pin, and a second concave provided at a radial outer side of the second external gear and does not contact the outer pin And a contact portion provided between the first recess and the second recess and in contact with the outer pin;
The facing end surfaces of the first external gear and the second external gear are located radially inward of the contact portion,
The radially outer portion of the outer peripheral corner of the facing end face of the first external gear and the second external gear is radially inward of a portion of the first external gear and the second external gear in contact with the external pin. It was set as the structure provided with the escape part which escapes.

Further, according to the present invention, there is provided an eccentricity for eccentrically rocking an internal gear, a first external gear and a second external gear meshing with the internal gear, and a first external gear and the second external gear. An eccentric rocking type reduction gear comprising a body shaft,
The internal gear includes an internal gear main body, a pin groove provided in the internal gear main body, and an outer pin rotatably disposed in the pin groove.
The outer pin is in contact with the first external gear and separated from the inner surface of the pin groove, and a second small diameter in contact with the second external gear and separated from the inner surface of the pin groove And a normal diameter portion in contact with the inner surface of the pin groove between the first small diameter portion and the second small diameter portion.

  According to the present invention, an effect is obtained that a lubricant coating can be sufficiently formed on the outer pin.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the eccentric rocking type reduction gear apparatus of Embodiment 1 which concerns on this invention. It is sectional drawing which shows the periphery of the outer pin of FIG. FIG. 3A is a perspective view showing a first example of the pin groove of the internal gear, and FIG. 3B is a perspective view showing a second example of the pin groove of the internal gear. 4A is a partial perspective view showing a first example of the external gear in FIG. 1, and FIG. 4B is a partial perspective view showing a second example of the external gear. It is sectional drawing of the eccentric rocking type reduction gear apparatus of Embodiment 2 which concerns on this invention. It is sectional drawing which shows the periphery of the outer pin of FIG. FIG. 7A is a partial perspective view showing a modification 1 of the external gear, and FIG. 7B is a modification 2 of the external gear. It is sectional drawing which shows the periphery of the outer pin of the eccentric rocking type reduction gear apparatus of Embodiment 3 which concerns on this invention.

  Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of an eccentric rocking type reduction gear transmission according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the periphery of the outer pin of FIG. FIG. 3A is a perspective view showing a first example of the pin groove of the internal gear, and FIG. 3B is a perspective view showing a second example of the pin groove of the internal gear. FIG. 4A is a partial perspective view showing a first example of the external gear in FIG. 1, and FIG. 4B is a partial perspective view showing a second example of the external gear. In this specification, the direction along the rotation axis O1 of the eccentric rocking type reduction gear G1 is taken as the axial direction, the direction perpendicular to the rotation axis O1 as the radial direction, and the rotation direction around the rotation axis O1 as the circumferential direction. Define.

  The eccentric rocking type reduction gear G1 includes an eccentric shaft 12 having a first eccentric body 14 and a second eccentric body 16, and a first external gear incorporated in the outer periphery of the first eccentric body 14 via roller bearings 18. 22 and a second external gear 24 incorporated in the outer periphery of the second eccentric body 16 via a roller bearing 20. Furthermore, the eccentric rocking type reduction gear includes an internal gear 26 with which the first external gear 22 and the second external gear 24 are meshed while meshing.

  The eccentric body shaft 12 typically functions as an input shaft for inputting rotational motion from the outside of the apparatus, and performs rotational motion around the rotational axis O1. To the eccentric body shaft 12, for example, a tap hole is used to connect an input-side member such as a gear, a pulley or the like.

  An outer peripheral surface of the first eccentric body 14 has a curved surface shape of a cylindrical side surface, and a central axis of the outer peripheral surface is eccentric from the rotation axis O1. Similarly, the outer peripheral surface of the second eccentric body 16 is a side surface of a cylinder, and the central axis of the outer peripheral surface is eccentric from the rotation axis O1. For example, the magnitudes of eccentricities of the first eccentric body 14 and the second eccentric body 16 are equal to each other, and the eccentric directions are different from each other by 180 degrees in the rotational phase of the eccentric body shaft 12 or the like.

  The first external gear 22 is pivotally mounted on the outer periphery of the first eccentric body 14 via the first roller bearing 18 and is in meshing engagement with the internal gear 26. The second external gear 24 is pivotally mounted on the outer periphery of the second eccentric 16 via the second roller bearing 20 and is in meshing engagement with the internal gear 26. The first external gear 22 and the second external gear 24 have a plurality of inner pin holes 226, 246 at positions offset from the axial center, and the plurality of inner pins 28 pass through. Furthermore, the first external gear 22 and the second external gear 24 respectively have trochoid tooth portions 223 and 243 (see FIG. 4) at the outermost peripheral portions. The first external gear 22 and the second external gear 24 have the same number of external teeth.

  The internal gear 26 is rotatable in an internal gear main body 26A integrated with the casing 31, a plurality of pin grooves 26C provided on the inner peripheral side of the internal gear main body 26A, and a plurality of pin grooves 26C. And a plurality of supported outer pins 26B. The outer pin 26B has a cylindrical shape. The number of internal teeth (the number of outer pins 26B) of the internal gear 26 is slightly different from the number of external teeth of the first external gear 22 (for example, one more).

  When the first external gear 22 and the second external gear 24 are viewed as a pair of members, the first carrier body 32 is provided on one side and the opposite side of the axial direction of the pair of members. The second carrier bodies 34 are respectively connected. The first carrier body 32 and the second carrier body 34 are supported by the casing 31 via a first angular contact ball bearing 36 and a second angular contact ball bearing 38 which are assembled in a back-to-back manner. The first carrier body 32 and the second carrier body 34 rotatably support the eccentric shaft 12 via the ball bearings 40 and 42.

<Deceleration action>
With the above configuration, when the eccentric shaft 12 rotates, the first eccentric 14 and the second eccentric 16 eccentrically rotate, and the first external gear 22 and the second external gear 24 have a phase difference of 180 degrees. It is rocked. The presence of the two external gears (the first external gear 22 and the second external gear 24) makes it possible to increase the transmission capacity and maintain the strength, and the first external gear 22 and the second external gear 24. By swinging with a phase difference of 180 degrees with respect to each other, it is possible to maintain the rotational balance of the eccentric rocking type reduction gear G1.

  The first external gear 22 and the second external gear 24 internally mesh with the internal gear 26. In the first embodiment, the internal gear main body 26A is integrated with the casing 31. Therefore, the first external gear 22 and the second external gear 24 rotate relative to the internal gear 26 by the difference in the number of teeth (rotation) each time the eccentric shaft 12 makes one rotation. The rotation components of the first external gear 22 and the second external gear 24 are transmitted to the first carrier body 32 and the second carrier body 34 through the inner pins 28 penetrating the inner pin holes 226, 246. . As a result, the rotational movement of the eccentric shaft 12 is decelerated at a reduction ratio of 1 / (the number of teeth common to the first external gear 22 and the second external gear 24), and the first carrier body 32 and the 2) It can be taken out as rotation of the carrier body 34.

<Details around the outer pin>
As shown in FIGS. 2 and 3A, the pin groove 26C of the internal gear 26 is provided with a first recess 261 not in contact with the outer pin 26B radially outward of the first external gear 22. A second recess 262 not in contact with the outer pin 26 B is provided radially outward of the second external gear 24. Furthermore, the pin groove 26C is provided with a contact portion 263 that is in contact with the outer pin 26B between the first recess 261 and the second recess 262. Also, with the first recess 261, the center contact portion 263 and the second recess 262 as one set, contact portions 264 and 265 at both ends contacting with the outer pin 26B are provided on both sides in the axial direction of this set of configuration. It is provided.

  As shown in FIG. 3A, of the pin grooves 26C, the contact portions 263, 264, and 265 have a shape along the outer peripheral surface of the outer pin 26B, that is, a curved shape of a cylindrical side surface. The first recess 261 and the second recess 262 have a curved surface shape of a substantially cylindrical side surface, but the diameter is larger than the diameter of the outer pin 26B or the diameter of the contact portions 263, 264, 265. In addition, as shown to FIG. 3 (B), it replaces with the 1st recessed part 261 and the 2nd recessed part 262, and the 1st recessed part 261X and the 2nd recessed part 262X may be provided in the pin groove 26C. The first recess 261X and the second recess 262X have a configuration in which concave grooves are continuous in the circumferential direction of the internal gear main body 26A.

  The facing end faces 221 and 241 of the first external gear 22 and the second external gear 24 are located radially inward of the contact portion 263. The outer peripheral corner of the end face 221 of the first external gear 22 and the outer peripheral corner of the end face 241 of the second external gear 24 are outer pins of the first external gear 22 and the second external gear 24. Recesses 222, 242 are provided to escape radially inward of the portion in contact with 26B.

  The relief portion 222 is, as shown in FIG. 4A, formed of an inclined surface which spreads in a substantially planar manner from the peak portion of the tooth portion 223 to the valley portion. The inclined surface is inclined with respect to the end face 221 so as to be positioned more axially outward as it is positioned radially outward. Here, axially outward means a direction from the end face 221 to the end face 224 on the opposite side. In this configuration, the clearance portion 222 is formed large at the peak portion of the tooth portion 223 and small at the valley portion. As shown in FIG. 4B, the first external gear 22 is provided with a relief portion 222X having substantially the same width in the axial direction between the peak portion and the valley portion of the tooth portion 223. It is also good. The relief portion 222 </ b> X is inclined at substantially the same angle with respect to the end surface 221 from the mountain portion to the valley portion of the tooth portion 223. The relief portion 242 of the second external gear 24 may have the same shape as the relief portion 222 and may have a shape similar to the relief portion 222X.

  As shown in FIG. 2, in the cross section, the axial width L1 of the first recess 261 is longer than the axial width L3 of the contact surface S1 between the first external gear 22 and the outer pin 26B, and in the radial direction As seen, the entire axial area of the contact surface S1 is included inside the first recess 261. That is, the axially outer end p1 of the first recess 261 is located axially outward when viewed in the radial direction from the axially outer end p3 of the first external gear 22. Further, the axially outer end portion p4 of the relief portion 222 is positioned axially inward when viewed in the radial direction from the axially inner end portion p2 of the first recess 261. Here, the term "axially outward" means a direction from the end face 221 on the apparatus center side of the first external gear 22 toward the end face 224 outside the apparatus in the axial direction, and the axially inward means the apparatus in the axial direction It means the direction from the outer end face 224 to the end face 221 on the center side of the apparatus. Moreover, each end p1-p4 is illustrated as a position when it sees from radial direction.

  Similarly, in the cross section, the axial width L2 of the second recess 262 is longer than the axial width L4 of the contact surface S2 between the second external gear 24 and the outer pin 26B, and when viewed in the radial direction The entire axial area of the surface S2 is included inside the second recess 262. That is, the axially outer end portion p5 of the second recess 262 is positioned axially outward as viewed in the radial direction from the axially outer end portion p7 of the second external gear 24. The axially outer end p <b> 8 of the relief portion 242 is axially inward of the axially inner end p <b> 6 of the second recess 262 as viewed in the radial direction. Here, the term "axially outward" means a direction from the end face 241 of the second external gear 24 on the apparatus center side toward the end face 244 outside the apparatus in the axial direction, and the axially inward means an apparatus in the axial direction The direction from the outer end face 244 to the end face 241 on the center side of the apparatus is meant. Moreover, each end part p5-p8 is illustrated as a position when it sees from radial direction.

  Further, according to the above configuration, the width L5 in the axial direction of the central contact portion 263 is smaller than the width L6 in the axial direction of the relief portions 222 and 242 of the first external gear 22 and the second external gear 24.

  The cross section of FIG. 2 shows a cross section of an angular position of the first external gear 22 and the second external gear 24 in the circumferential direction. The arrangement relationship between the first concave portion 261 and the second concave portion 262 and the contact surfaces S1 and S2 is established in the cross section of all angular positions in the circumferential direction of the first external gear 22 and the second external gear 24. Is more effective. However, it does not have to be true for the cross sections of all angular positions, and if it is true for most of the angle ranges, sufficient effects to be described later can be achieved.

  In the first embodiment, the first external gear 22 and the second external gear 24 are in contact with each other at the end faces 221 and 241, but may be separated, for example, through a spacer.

<Action around the outer pin>
When the first external gear 22 and the second external gear 24 swing, the first external gear 22 and the second external gear 24 contact the outer pin 26B through the contact surfaces S1 and S2 (see FIG. 2). The contact pressure is applied, and the outer pin 26B rotates inside the pin groove 26C of the internal gear 26 under the contact pressure. At this time, the outer pin 26B and the pin groove 26C make sliding contact, but since there are the first recess 261 and the second recess 262 on the opposite side of the contact surfaces S1 and S2 to which a large contact surface pressure is applied, In part, the outer pin 26B does not contact the inner surface of the pin groove 26C.

  In the conventional configuration without the first recess 261, the second recess 262 and the reliefs 222 and 242, the contact pressure applied to the outer pin from the external gear causes the outer surface to be opposite to the side in contact with the external gear. A large contact pressure is applied between the pin and the inner surface of the pin groove. Then, a sliding contact is generated between the outer pin and the inner surface of the pin groove in the state of having a large contact surface pressure, which causes a problem that a coating of lubricating oil is hardly generated on this portion of the outer pin.

  On the other hand, in the portion of the eccentric rocking type reduction gear G1 according to the first embodiment, such a large contact surface pressure does not cause sliding contact with the outer pin 26B and the inner surface of the pin groove 26C. Rolling contact with the first external gear 22 and the second external gear 24 occurs. As a result, a film of lubricating oil is sufficiently generated on the entire outer peripheral surface of the outer pin 26B.

  Furthermore, since the contact portion 263 contacts the outer pin 26B between the first recess 261 and the second recess 262 of the pin groove 26C, high support rigidity can be secured between the pin groove 26C and the outer pin 26B. In addition, high support rigidity is secured between the internal gear 26 and the first external gear 22 and the second external gear 24. And by these, the torsional rigidity of the eccentric rocking type reduction gear G1 is improved.

  As described above, according to the eccentric rocking type reduction gear G1 of the first embodiment, the first recessed portion is provided radially outward of the first external gear 22 and the second external gear 24 in the pin groove 26C. 261 and a second recess 262 are provided. Furthermore, the end faces 221 and 241 of the first external gear 22 and the second external gear 24 are located radially inward of the contact portion 263 between the first recess 261 and the second recess 262, and the end surface 221 The relief portions 222 and 242 are provided at outer peripheral corners of the portion 241. As a result, a film of lubricating oil can be sufficiently formed on the entire outer peripheral surface of the outer pin 26B, and the durability of the outer pin 26B and the pin groove 26C can be improved. Furthermore, the presence of the central contact portion 263 can maintain the high support rigidity of the first external gear 22 and the second external gear 24 and improve the torsional rigidity of the eccentric rocking type reduction gear G1.

  Further, according to the eccentric rocking type reduction gear G1 of the first embodiment, as shown in FIG. 2, the axial length L6 of the relief portions 222 and 242 is equal to the axial width L5 of the central contact portion 263. Too big. Therefore, the contact surface pressure applied to the outer pin 26B from the first external gear 22 and the second external gear 24 is directly transmitted to the contact portion 263 of the pin groove 26C in the axial center area of the outer pin 26B. You can reduce the number of sites. Therefore, in the outer pin 26B, the portion where the sliding contact occurs at a large contact pressure can be further reduced, whereby the formation of the coating on the outer pin 26B can be performed more sufficiently.

  Furthermore, according to the eccentric rocking type reduction gear G1 of the first embodiment, as shown in FIG. 2, the axially outward end portion p1 of the first recess 261 is axially outward of the first external gear 22. It is positioned axially outward as viewed in the radial direction from the end portion p3 of. Similarly, the axially outer end portion p2 of the second recess 262 is located axially outward of the axially outer end portion p4 of the first external gear 22 as viewed in the radial direction. With this configuration, the contact surface pressure applied to the outer pin 26B from the first external gear 22 and the second external gear 24 in the axially outward range of the outer pin 26B is the contact portion 264 of the pin groove 26C, It is possible to eliminate the part that is directly transmitted to the H.265. Therefore, the portion where the sliding contact occurs in the outer pin 26B due to the large contact pressure can be further reduced, whereby the formation of the coating on the outer pin 26B can be performed more sufficiently.

Second Embodiment
FIG. 5 is a cross-sectional view of an eccentric rocking type reduction gear transmission of a second embodiment according to the present invention. FIG. 6 is a cross-sectional view showing the periphery of the outer pin of FIG.

  The eccentric rocking type reduction gear G2 of the second embodiment is different from that of the first embodiment in the shapes of the first recess 261A and the second recess 262A of the pin groove 26C. Hereinafter, the same components as in the first embodiment will be assigned the same reference numerals and detailed explanations thereof will be omitted.

  As shown in FIGS. 5 and 6, the pin groove 26C of the second embodiment is provided with a first concave portion 261A and a second concave portion 262A in which the outline of the cross section orthogonal to the circumferential direction has a curved shape. The first recess 261A is provided radially outward of the first external gear 22 and does not contact the outer pin 26B. The second recess 262A is provided radially outward of the second external gear 24 and does not contact the outer pin 26B. Furthermore, in the pin groove 26C, a contact portion 263A that contacts the outer pin 26B is provided between the first recess 261A and the second recess 262. Further, with the first concave portion 261A, the second concave portion 262A and the contact portion 263A as one set, contact portions 264A, 265A at both ends in contact with the outer pin 26B are provided on both sides in the axial direction of this set of configuration. ing.

  Among the pin grooves 26C, the contact portions 263A, 264A, 265A have a shape along the outer peripheral surface of the outer pin 26B, that is, a curved shape of a cylindrical side surface. The first concave portion 261A and the second concave portion 262A correspond to the corner portions (corner portions with the contact portions 263, 264, and 265) of the first concave portion 261 and the second concave portion 262 (FIG. 3A) of the first embodiment. It has a gentle shape. Alternatively, it has a shape in which the corner portions of the first concave portion 261X and the second concave portion 262X (FIG. 3B) of the modification are smoothed.

  The facing end faces 221 and 241 of the first external gear 22 and the second external gear 24 are located radially inward of the contact portion 263A. Further, relief portions 222 and 242 similar to those of the first embodiment are provided on an outer peripheral corner portion of the end face 221 of the first external gear 22 and an outer peripheral corner portion of the end face 241 of the second external gear 24. . The outlines of the cross sections of the relief portions 222 and 242 may be curved so that the corner portions (corner portions of the boundary between the surface in contact with the outer pin 26B) are smooth.

  As shown in FIG. 6, the axial width L1A of the first recess 261A is longer than the axial width L3 of the contact surface S1 between the first external gear 22 and the outer pin 26B, and can be viewed in the radial direction. The entire axial area of the contact surface S1 is included inside the first recess 261A. That is, the axially outer end portion p1A of the first concave portion 261A is located axially outward as viewed in the radial direction from the axially outer end portion p3 of the first external gear 22. Further, the axially outer end portion p4 of the relief portion 222 is positioned axially inward when viewed in the radial direction from the axially inner end portion p2A of the first recess 261A. Axial outward and axial inward are defined as described in the first embodiment. Further, the end portions p1A, p2A, p3 and p4 are illustrated as positions when viewed from the radial direction.

  Similarly, the axial width L2A of the second recess 262A is longer than the axial width L4 of the contact surface S2 between the second external gear 24 and the outer pin 26B, and when viewed in the radial direction, The entire axial direction is included inside the second recess 262A. That is, the axially outer end p5A of the second recess 262A is located axially outward as viewed in the radial direction from the axially outer end p7 of the second external gear 24. Further, the axially outer end portion p8 of the relief portion 242 is positioned axially inward when viewed in the radial direction from the axially inner end portion p6A of the second recess 262A. Axial outward and axial inward are defined as described in the first embodiment. Further, the end portions p5A, p6A, p7 and p8 are illustrated as positions when viewed from the radial direction.

  Further, according to the above configuration, the axial width L5A of the central contact portion 263A is smaller than the axial width L6 of the relief portions 222 and 242 of the first external gear 22 and the second external gear 24.

  The cross section of FIG. 5 shows a cross section of an angular position of the first external gear 22 and the second external gear 24 in the circumferential direction. The arrangement relationship between the first concave portion 261A and the second concave portion 262A and the contact surfaces S1 and S2 is established in the cross section of all angular positions in the circumferential direction of the first external gear 22 and the second external gear 24. Is more effective. However, it does not have to be true for the cross sections of all angular positions, and if it is true for most of the angle ranges, sufficient effects can be achieved.

  In the second embodiment, the first external gear 22 and the second external gear 24 are in contact with each other at the end faces 221 and 241, but may be separated, for example, through a spacer.

<Action around the outer pin>
When the first external gear 22 and the second external gear 24 swing, the first external gear 22 and the second external gear 24 contact the outer pins 26B via the contact surfaces S1 and S2 (see FIG. 5). The contact pressure is applied, and the outer pin 26B rotates inside the pin groove 26C of the internal gear 26 under the contact pressure. At this time, the outer pin 26B and the pin groove 26C make sliding contact, but since there are the first recess 261A and the second recess 262A on the opposite side of the contact surfaces S1 and S2 to which a large contact surface pressure is applied, In part, the outer pin 26B does not contact the inner surface of the pin groove 26C. Therefore, a sliding contact does not occur between the outer pin 26B and the inner surface of the pin groove 26C at a portion where a large contact surface pressure is applied, and a sufficient coating of lubricating oil can be formed on the entire outer peripheral surface of the outer pin 26B. it can.

  Furthermore, the first concave portion 261A and the second concave portion 262A of the second embodiment have a curved surface shape with a smooth boundary with the contact portions 263A, 264A, and 265A. Therefore, even when the outer pin 26B is elastically deformed by the contact surface pressure, the contact surface pressure is not concentrated at the boundary between the first recess 261A and the second recess 262A and the contact portions 263A, 264A, 265A.

  Furthermore, in the configuration of the second embodiment as well, since the contact portion 263A contacts the outer pin 26B between the first recess 261A and the second recess 262A, high support rigidity is obtained between the pin groove 26C and the outer pin 26B. Can be secured. In addition, high support rigidity is secured between the internal gear 26 and the first external gear 22 and the second external gear 24. Thereby, the torsional rigidity of the eccentric rocking type reduction gear G1 is improved.

  As described above, according to the eccentric rocking type reduction gear G2 of the second embodiment, the first recess 261A and the second recess 262A of the pin groove 26C have a curved shape. For this reason, even when the outer pin 26B is elastically deformed by the contact surface pressure, the contact surface pressure does not concentrate on the boundary between the first recess 261A and the second recess 262A and the contact portions 263A, 264A, 265A. It is possible to maintain the coating of the lubricant produced. Therefore, in addition to obtaining the same effects as the first embodiment, the durability of the outer pin 26B and the pin groove 26C can be further improved.

(Modification)
FIG. 7A is a partial perspective view showing a modification 1 of the external gear, and FIG. 7B is a modification showing a modification 2 of the external gear.

  The relief portion 222 of the first external gear 22 shown in the first and second embodiments is a relief portion 222B as shown in FIG. 7 (A) or a relief portion 222C as shown in FIG. 7 (B). It may be deformed.

  The relief portions 222B and 222C in FIGS. 7A and 7B are formed in a step-like shape between the tooth portion 223 and the end face 221 in the first external gear 22. As a result, the outer peripheral corner of the end face 221 of the first external gear 22 escapes radially inward of the teeth 223 and does not contact the outer pin 26B. As shown in FIG. 7A, the stepped relief portions 222B and 222C have radial heights from the axial center of the first external gear 22 at respective portions in the circumferential direction of the first external gear 22. It may be formed at a substantially constant height. Alternatively, as shown in FIG. 7B, the step from the peak of the tooth 223 and the step from the valley may be substantially equal.

  The same modification as that of FIGS. 7A and 7B may be applied to the relief portion 242 of the second external gear 24.

  Also in the configuration of the first modification, the same effects as those of the first embodiment and the second embodiment can be obtained.

(Embodiment 3)
FIG. 8 is a cross-sectional view showing the periphery of the outer pin of the eccentric rocking speed reducer according to a third embodiment of the present invention.

  The eccentric rocking type reduction gear transmission of the third embodiment is different from the first embodiment and the second embodiment in the configuration of the outer pin 26X and the periphery thereof, and the other configurations are the same as the first embodiment and the second embodiment. Detailed description of the same configuration is omitted.

  The pin groove 26C of the internal gear 26 of the third embodiment does not have a recess as shown in the first embodiment or the second embodiment, and the inner surface of the pin groove 26C has a curved shape of a cylindrical side surface.

  The outer pin 26X of the third embodiment is a pin-like member having a first small diameter portion 26X1 and a second small diameter portion 26X2. The first small diameter portion 26X1 is located radially outward of the first external gear 22, contacts the tooth portion 223, but does not contact the inner surface of the pin groove 26C. The second small diameter portion 26X2 is located radially outward of the second external gear 24, contacts the tooth portion 243, but does not contact the inner surface of the pin groove 26C.

  In the outer pin 26X, a normal diameter portion 26X3 larger in diameter than the first small diameter portion 26X1 and the second small diameter portion 26X2 is provided between the first small diameter portion 26X1 and the second small diameter portion 26X2. In the outer pin 26X, a normal diameter portion 26X4 having a larger diameter than the first small diameter portion 26X1 and the second small diameter portion 26X2 on the end side of the first small diameter portion 26X1 and the second small diameter portion 26X2 in the axial direction. , 26x5 are provided. The normal diameter portions 26X3, 26X4, 26X5 do not contact the tooth portions 223, 243 of the first external gear 22 and the second external gear 24, but contact the inner surface of the pin groove 26C. The first small diameter portion 26X1, the second small diameter portion 26X2, and the normal diameter portions 26X3, 26X4, 26X5 have cylindrical shapes that are concentric with each other.

  In the eccentric rocking type reduction gear according to the third embodiment, when the first external gear 22 and the second external gear 24 are oscillated, the outer pin 26 X is formed of the first external gear 22 and the second external gear 24. It rotates inside the pin groove 26C in a state where a large contact surface pressure is applied from the teeth 223, 243. At this time, the outer pin 26X and the pin groove 26C make sliding contact, but the opposite side of the teeth 223 and 243 to which a large contact surface pressure is applied is due to the first small diameter portion 26X1 and the second small diameter portion 26X2 of the outer pin 26X. , Not in contact with the pin groove 26C. Therefore, according to the eccentric rocking reduction gear device of the third embodiment, the outer pin 26X does not have a sliding contact at a portion to which a large contact surface pressure is applied, and a sufficient lubricating oil film is formed on the entire outer peripheral surface of the outer pin 26X. Can be generated. Thereby, the durability of the outer pin 26X can be improved.

  Furthermore, according to the eccentric rocking type reduction gear transmission of the third embodiment, the outer pin 26X is formed on both sides of the first small diameter portion 26X1 in the axial direction and on both sides of the second small diameter portion 26X2 in normal diameter portions 26X3, 26X4, 26X5. Contacts the pin groove 26C. Therefore, high support rigidity is secured between the pin groove 26C and the outer pin 26X, thereby ensuring high support rigidity between the internal gear 26 and the first external gear 22 and the second external gear 24. Be done. Thereby, the torsional rigidity of the eccentric rocking type reduction gear according to the third embodiment can be improved.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. For example, in the above-described embodiment, a so-called center crank type eccentric rocking reduction gear is shown in which one eccentric body shaft is disposed at the shaft center of the reduction gear. However, the present invention may be applied to a so-called distribution-type eccentric rocking reduction gear in which two or more eccentric body shafts are disposed offset from the shaft center of the reduction gear.

  In the above embodiment, the present invention is applied to an eccentric rocking type reduction gear having two external gears, but the present invention can be applied to an eccentric rocking gear having three or more external gears. May apply. In this case, any one of the three or more external gears corresponds to the first external gear, and one adjacent thereto corresponds to the second external gear. Other details described in the embodiment can be appropriately changed without departing from the scope of the invention.

G1, G2 Eccentric rocking type reduction gear 12 Eccentric body shaft 14 1st eccentric body 16 2nd eccentric body 22 1st external gear 24 2nd external gear 26 internal gear 26A internal gear main body 26B, 26X outer pin 26C Pin groove 28 Inner pin 32 First carrier body 34 Second carrier body 221, 241 End face (facing end face)
222, 222B, 222C, 222X, 242 relief part 223, 243 tooth part 224, 244 end face 226, 246 inner pin hole 261, 261A, 261X first recess 262, 262A, 262X second recess 263, 263A, 264, 264A, 265, 265A contact portion 26X1 first small diameter portion 26X2 second small diameter portion 26X3, 26X4, 26X5 normal diameter portion

Claims (6)

An internal gear, a first external gear and a second external gear meshing with the internal gear, and an eccentric shaft for eccentrically rocking the first external gear and the second external gear Eccentric rocking type reduction gear
The internal gear includes an internal gear main body, a pin groove provided in the internal gear main body, and an outer pin rotatably disposed in the pin groove.
The pin groove is provided at a radially outer side of the first external gear and does not contact the outer pin, and a second concave provided at a radial outer side of the second external gear and does not contact the outer pin And a contact portion provided between the first recess and the second recess and in contact with the outer pin;
The facing end surfaces of the first external gear and the second external gear are located radially inward of the contact portion,
The radially outer portion of the outer peripheral corner of the facing end face of the first external gear and the second external gear is radially inward of a portion of the first external gear and the second external gear in contact with the external pin. There is a relief to run away,
Eccentric rocking type reduction gear. The axial length of the relief portion is greater than the axial length of the contact portion,
The eccentric rocking type reduction gear according to claim 1. The first recess and the second recess have a curved shape in a cross section orthogonal to the circumferential direction of the internal gear,
The eccentric rocking type reduction gear according to claim 1 or 2. The direction from the end face where the first external gear and the second external gear face each other in the axial direction to the end face on the opposite side of the first external gear is regarded as axially outward.
When viewed from the radial direction, the axially outward end of the first recess is axially outward of the axially outward end of the first external gear.
The eccentric rocking type reduction gear according to any one of claims 1 to 3. In the axial direction, the direction from the end face where the first external gear and the second external gear face to the opposite end face of the second external gear is taken as the axial direction outward.
When viewed in the radial direction, the axially outward end of the second recess is axially outward of the axially outward end of the second external gear.
The eccentric rocking type reduction gear according to any one of claims 1 to 4. An internal gear, a first external gear and a second external gear meshing with the internal gear, and an eccentric shaft for eccentrically rocking the first external gear and the second external gear Eccentric rocking type reduction gear
The internal gear includes an internal gear main body, a pin groove provided in the internal gear main body, and an outer pin rotatably disposed in the pin groove.
The outer pin is in contact with the first external gear and separated from the inner surface of the pin groove, and a second small diameter in contact with the second external gear and separated from the inner surface of the pin groove And a normal diameter portion in contact with the inner surface of the pin groove between the first small diameter portion and the second small diameter portion.
Eccentric rocking type reduction gear.

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