JP2018048701A - Eccentric oscillation type reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more improve the twisting rigidity of a carrier while restricting larger in size of the whole device.SOLUTION: An eccentric oscillation type reduction gear G1 that comprises: first and second external tooth gears 11 and 12; an internal gear 20; a plurality of crank shafts 22 for fluctuation-turning the first and second external tooth gears; first and second carriers 31 and 32 respectively disposed on one side and the other side of the first and second external tooth gears in the axial direction; a connection member 33 for connecting the first carrier to the second carrier; and an insert ring 40 disposed between the first and second external tooth gears in that the first and second external tooth gears do not contact in the axial direction. The crank shafts include: first and second eccentric bodies 51 and 52 to which the first and second external tooth gears are externally fitted; and a central positioning part 23 having a shaft center C23 to match a shaft center C22 of the crank shaft provided between the first and second eccentric bodies. The insert ring is positioned radially by inscribing or circumscribing each central positioning part of the plurality of crank shafts.SELECTED DRAWING: Figure 1

Description

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

  In Patent Document 1, a first external gear, a second external gear arranged in an axial direction with the first external gear, and an internal gear meshing with the first external gear and the second external gear are disclosed. An eccentric oscillating speed reduction device including a toothed gear is disclosed.

  The speed reducer includes a plurality of crankshafts that are disposed at positions offset from the axis of the internal gear and that swing and rotate the first external gear and the second external gear. A first carrier is disposed on one side in the axial direction of the first external gear. A second carrier is disposed on the other axial side of the second external gear.

  The first carrier and the second carrier are integrated by being connected by a connecting member called a carrier pin, and constitute a carrier as a whole. A carrier pin hole is formed in the first external gear and the second external gear so that the carrier pin penetrates (freely fits) without contact.

  The first external gear and the second external gear are not in contact with each other in the axial direction, and an insertion ring is provided between the first external gear and the second external gear. The insertion ring is externally fitted to each carrier pin, and regulates the axial interval between the first external gear and the second external gear.

Japanese Patent Laying-Open No. 2015-161235 (FIGS. 3 and 4)

  In such an eccentric oscillating type speed reducer, there is a problem that if the meshing property of the gear part and the sliding property of each part are deteriorated due to the twist of the carrier, the driving efficiency is reduced or the noise is increased. is there. In order to increase the torsional rigidity of the carrier, it is effective to increase the rigidity of the connecting member (carrier pin) that connects the first carrier and the second carrier.

  However, this type of reduction gear has a situation in which there is almost no dimensional margin for each member. In addition, conventionally, each carrier pin has been fitted with an outer ring for restricting the axial interval between the first external gear and the second external gear. The fact was that it was difficult to design with rigidity.

  The present invention has been made in view of such problems, and it is an object of the present invention to provide an eccentric oscillating speed reduction device that can further increase the torsional rigidity of the carrier while suppressing an increase in the size of the entire device. It is said.

  The present invention relates to a first external gear, a second external gear arranged in an axial direction with the first external gear, and an internal tooth meshing with the first external gear and the second external gear. A gear, a plurality of crankshafts arranged at positions offset from the axis of the internal gear and swinging and rotating the first external gear and the second external gear, and an axial direction of the first external gear. A first carrier arranged on the side, a second carrier arranged on the other axial side of the second external gear, a connecting member for connecting the first carrier and the second carrier, and the first An eccentric oscillating type speed reducer in which the first external gear and the second external gear do not contact in the axial direction. The crankshaft is externally fitted with a first eccentric body on which the first external gear is fitted and the second external gear. A second positioning body, and a central positioning portion provided between the first eccentric body and the second eccentric body and having an axis that coincides with the axis of the crankshaft. The above-described problems are solved by adopting a configuration in which each crankshaft is positioned in the radial direction by inscribed or circumscribed with each center positioning portion.

  In the present invention, the crankshaft is provided with a first eccentric body to which the first external gear is fitted and a second eccentric body to which the second external gear is fitted, and the first eccentric body and the first eccentric body A central positioning portion is provided between the two eccentric bodies and has an axis that coincides with the axis of the crankshaft.

  Then, the insertion wheel is positioned in the radial direction by inscribed or circumscribed to each central positioning portion. As a result, in comparison with a configuration in which the insertion ring is fitted around each carrier pin, the dimensional restriction caused by the insertion ring can be reduced by a mechanism that will be described in detail later, and the overall size of the apparatus is increased. Thus, it is possible to more easily perform a design that increases the torsional rigidity of the carrier.

  According to the present invention, the torsional rigidity of the carrier can be further increased while suppressing an increase in the size of the entire apparatus.

Sectional drawing of the eccentric rocking | fluctuation type deceleration device which concerns on an example of embodiment of this invention FIG. Sectional view along the arrow III-III line of FIG. The principal part expanded sectional view of the eccentric rocking | fluctuation type deceleration device which concerns on the other example of embodiment of this invention. Sectional drawing which follows the arrow VV line of FIG.

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  FIG. 1 is a cross-sectional view of an eccentric oscillating speed reduction device G1 according to an example of an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

  Describing from the outline, the eccentric oscillating type reduction gear G1 includes a first external gear 11, a second external gear 12 arranged in the axial direction with the first external gear 11, a first An internal gear 20 that meshes with the external gear 11 and the second external gear 12.

  The reduction gear G1 is disposed at a position offset by R22 from the axis C20 of the internal gear 20, and includes a plurality of crankshafts 22 that swing and rotate the first external gear 11 and the second external gear 12. . A first carrier 31 is arranged on one axial direction side of the first external gear 11. A second carrier 32 is disposed on the other axial side of the second external gear 12. The first carrier 31 and the second carrier 32 are connected by a carrier pin (connecting member) 33.

  The first external gear 11 and the second external gear 12 are not in contact with each other in the axial direction, and an insertion ring 40 is provided between the first external gear 11 and the second external gear 12. ing. The insertion wheel 40 regulates the axial interval between the first external gear 11 and the second external gear 12. The insertion wheel 40 is positioned in the radial direction by circumscribing each central positioning portion 23 (described later) of the plurality (three in this example) of the crankshaft 22.

  Details will be described below.

  The eccentric oscillating speed reduction device G1 includes a first external gear 11 and a second external gear 12 arranged side by side in the axial direction in order to ensure a large transmission capacity of the entire device. Further, in order to swing and rotate the first external gear 11 and the second external gear 12, the speed reducer G1 has a plurality (three in this example) at positions offset by R22 from the axis C20 of the internal gear 20. This includes only one crankshaft 22.

  Each crankshaft 22 includes a first eccentric body 51 on which the first external gear 11 is fitted and a second external gear in order to swing and rotate the first external gear 11 and the second external gear 12. And a second eccentric body 52 to which 12 is externally fitted.

  The axis C51 of the first eccentric body 51 is eccentric by a first eccentric amount δ51 with respect to the axis C22 of the crankshaft 22, and the axis C52 of the second eccentric body 52 is offset with respect to the axis C22 of the crankshaft 22. The second eccentric amount δ52 is eccentric. That is, the first eccentric body 51 and the second eccentric body 52 have an outer periphery that is eccentric with respect to the axis C22 of the crankshaft 22. The first eccentricity δ51 and the second eccentricity δ52 are equal (first eccentricity δ51 = second eccentricity δ52). The eccentric phase difference between the first eccentric body 51 and the second eccentric body 52 is 180 degrees in this example (decentered in directions away from each other).

  The three crankshafts 22 have the same configuration, and the phases of the first eccentric bodies 51 located at the same position in the axial direction of the respective crankshafts 22 are the same. Further, the phases of the second eccentric bodies 52 at the same position in the axial direction of each crankshaft 22 are also the same.

  Between the first eccentric body 51 of the crankshaft 22 and the first eccentric body bearing hole 11E formed in the first external gear 11, a first eccentric body bearing 61 is disposed. Between the second eccentric body 52 of the crankshaft 22 and the second eccentric body bearing hole 12E formed in the second external gear 12, a second eccentric body bearing 62 is disposed.

  The first eccentric body bearing 61 includes a first rolling element 61A composed of rollers, and a first retainer 61B that supports the first rolling element 61A. The first eccentric body bearing 61 does not have a dedicated inner / outer ring, the first eccentric body 51 also functions as the inner ring, and the first external gear 11 also functions as the outer ring. The 2nd eccentric body bearing 62 is also provided with the 2nd rolling element 62A comprised by the roller, and the 2nd retainer 62B which supports this 2nd rolling element 62A. The second eccentric body bearing 62 also does not have a dedicated inner / outer ring, the second eccentric body 52 also functions as an inner ring, and the second external gear 12 also functions as an outer ring.

  The first external gear 11 and the second external gear 12 are in mesh with the internal gear 20. The internal gear 20 is incorporated rotatably in the outer periphery of the internal gear main body 20A integrated with the casing 21 of the reduction gear G1, the support pin 20B supported by the internal gear main body 20A, and the support pin 20B. And an internal roller 20 </ b> C constituting internal teeth of the internal gear 20. The number of teeth of the internal gear 20 is slightly larger (by 2 in this example) than the number of teeth of the first external gear 11 and the second external gear 12.

  A first carrier 31 is disposed on the axially opposite load side (one axial direction side) of the first external gear 11. A second carrier 32 is disposed on the axial load side (the other axial side) of the second external gear 12.

  The first carrier 31 and the second carrier 32 constitute a carrier 30 by being connected via three (only one is shown) carrier pins (connecting members) 33. The carrier pin 33 is integrally formed so as to protrude from the first carrier 31 (consisting of the same member as that of the first carrier 31), and is connected to the second carrier 32 via a carrier bolt 38.

  In this example, the shape of the cross section perpendicular to the axis of the carrier pin 33 (the cross section of FIG. 3) is “circular”. The cross-sectional area of the carrier pin 33 is constant in the axial direction. However, the speed reduction device G1 has a carrier that is relatively relative to the radial dimension of the internal gear 20 (for example, the pitch circle radius of the internal gear 20C) as compared with the conventional configuration, by a mechanism that will be described in detail later. The radius (cross-sectional area) of the pin 33 and / or the formation pitch circle radius of the carrier pin 33 (the dimension from the axis C20 of the internal gear 20 to the axis C33 of the carrier pin 33) RC33 is set larger. Is possible.

  Therefore, the radius R33 and the formation pitch circle radius RC33 of the carrier pin 33 are set to be slightly larger than those of the conventional art so as to obtain higher torsional rigidity. In this example, the carrier pin 33 has a circular cross-sectional shape (cross-sectional shape in FIG. 3), and the center of gravity C33G of the cross-section of the carrier pin 33 is equal to the axis C38 of the carrier bolt 38.

  The second carrier 32 is integrated with the output shaft 35 (configured integrally with the same member as the output shaft 35). The output shaft 35 is supported on the casing 21 by a pair of tapered roller bearings (only the taper roller bearing 36 on the anti-load side is shown in FIG. 1). The axis C35 of the output shaft 35 is concentric with the axis C48 of the input shaft 48 and the axis C20 of the internal gear 20 (C35 = C48 = C20).

  The first external gear 11 has a first center through hole 11A at the position of the first axis C11 of the first external gear 11, and the carrier pin 33 is inserted at a position offset from the first axis C11. A first carrier pin hole 11B is provided. The second external gear 12 has a second center through hole 12A at the position of the second axis C12 of the second external gear 12, and the carrier pin 33 is inserted at a position offset from the second axis C12. A second carrier pin hole 12B is provided. The carrier pin 33 always passes through the first carrier pin hole 11B and the second carrier pin hole 12B in a non-contact manner with a gap regardless of the oscillation of the first and second external gears 11 and 12. Yes.

  In the reduction gear G1, each crankshaft 22 is supported by the first carrier 31 and the second carrier 32 via a pair of tapered roller bearings 54 and 55 that are assembled face to face. The crankshaft 22 has a protruding portion 22A that protrudes from the first carrier 31 toward the axially opposite first external gear side. A sorting gear 39 is incorporated in the protrusion 22 </ b> A of the crankshaft 22.

  Since the reduction gear G1 has three crankshafts 22, a total of three sorting gears 39 are provided, one for each crankshaft 22 (only one is shown in FIG. 1). The three sorting gears 39 mesh with the input pinion 49 provided on the input shaft 48 at the same time. The input shaft 48 can be rotated by rotation of a drive source such as a motor (not shown). The input shaft 48 is supported by a roller bearing 56 incorporated in the first carrier 31 and a ball bearing 58 incorporated in the casing 21 (the opposite load side cover 21C).

  Hereinafter, the built-in configuration of the insert wheel 40 will be described in more detail. Note that when simply referred to as “diameter” in this specification, it means “radius” instead of “diameter”.

  An insertion ring 40 is disposed between the first external gear 11 and the second external gear 12 of the reduction gear G1. That is, the first external gear 11 and the second external gear 12 of the speed reducer G1 are not in contact with each other in the axial direction. The interval between the first external gear 11 and the second external gear 12 in the axial direction is regulated (or ensured) by the insertion wheel 40.

  The movement of the first external gear 11 toward the axially opposite load side is restricted by the axial end surface 31E of the first carrier 31 on the axial first external gear 11 side. The movement of the second external gear 12 toward the axial load side is regulated by the axial end surface 32E of the second carrier 32 on the axial second external gear 12 side.

  As already described, the crankshaft 22 has the first eccentric body 51 to which the first external gear 11 is fitted and the second eccentric body 52 to which the second external gear 12 is fitted. Yes.

  The crankshaft 22 according to the present embodiment further has a center positioning having an axis C23 that coincides with the axis C22 of the crankshaft 22 between the first eccentric body 51 and the second eccentric body 52 (center in the axial direction). Part 23. That is, the center positioning portion 23 (the outer periphery thereof) of the crankshaft 22 is concentric with the axis C22 of the crankshaft 22 (not eccentric: C22 = C23). The radius of the center positioning portion 23 (the distance from the axis C22 of the crankshaft 22 to the center positioning portion 23 (the outer periphery thereof)) is R23, and is constant over the entire periphery.

  In other words, the axis Ce23 of the circumscribed circle e23 of each center positioning portion 23 and the axis Ci23 of the inscribed circle i23 of each center positioning portion 23 coincide with the axis C20 of the internal gear 20. (C20 = Ce23 = Ci23). Therefore, the insertion wheel 40 can be positioned in the radial direction either by circumscribing each center positioning portion 23 or by inscribing it.

  In the embodiment shown in FIGS. 1 to 3, the insertion wheel 40 is positioned in the radial direction by bringing the insertion wheel 40 (a positioning surface 47 of a contact ring portion 42 described later) into contact with each central positioning portion 23. doing. In other words, the axis C40 of the insertion wheel 40 is the same as the axis Ce23 of the circumscribed circle e23 of the center positioning portion 23 (C40 = Ce23), and the radius of the inner periphery of the insertion wheel 40 (= the covered ring portion 42). The radius R47 of the positioning surface 47 is the same as the radius Re23 of the circumscribed circle e23 of each central positioning portion 23 (R47 = Re23).

  In this example, the crankshaft 22 integrally includes the first eccentric body 51 and the second eccentric body 52 or the central positioning portion 23 with the same material. The member (central positioning portion) may be connected with a key or the like to be integrated with the crankshaft body.

  As shown in FIG. 2, the radius R23 of the central positioning portion 23 is set to be the same as the distance L51M from the axis C22 of the crankshaft 22 to the outer periphery of the maximum eccentric portion 51M of the first eccentric body 51 in this embodiment. It is. “The outer circumference of the maximum eccentric portion 51M of the first eccentric body 51” refers to “the outer circumference of the first eccentric body 51 and the portion farthest from the axis C22 of the crankshaft 22”. Similarly, the radius R23 of the center positioning portion 23 is set to be the same as the distance L52M from the axis C22 of the crankshaft 22 to the outer periphery of the maximum eccentric portion 52M of the second eccentric body 52. “The outer periphery of the maximum eccentric portion 52M of the second eccentric body 52” refers to “the outer periphery of the second eccentric body 52 and the portion farthest from the axis C22 of the crankshaft 22”.

  That is, in this embodiment, the radius R23 of the central positioning portion 23 = the distance L51M from the axis C22 of the crankshaft 22 to the outer periphery of the maximum eccentric portion 51M of the first eccentric body 51 = the second from the axis C22 of the crankshaft 22 This is the distance L52M to the outer periphery of the maximum eccentric portion 52M of the eccentric body 52.

  In other words, the first eccentric body 51 and the second eccentric body 52 of the crankshaft 22 are arranged inside the circumscribed circle e23 of each central positioning portion 23 of the crankshaft 22 when viewed from the axial direction. It also means that it is just within. For this reason, in the present embodiment, the central positioning portion 23 formed in this size restricts the axial movement of the first retainer 61B of the first eccentric body bearing 61 and the second retainer 62B of the second eccentric body bearing 62. It has a function to do.

  In this embodiment, the entire insertion wheel 40 is formed in a ring shape. The insertion ring 40 includes an outer peripheral ring portion 41 that contacts the first external gear 11 and the second external gear 12 in the axial direction, an abutment ring portion 42 that is provided radially inside the outer peripheral ring portion 41, and have.

  The outer peripheral ring portion 41 of the insertion ring 40 has a substantially rectangular shape in cross section (cross section in FIGS. 1 and 2) passing through the axis C <b> 20 of the internal gear 20. The outer peripheral ring portion 41 has a first axial end surface 43 that contacts the axial end surface 11F of the first external gear 11 in the axial direction and a second axial contact that contacts the axial end surface 12F of the second external gear 12 in the axial direction. An axial end face 44 is opposed to the axial direction. The first axial end face 43 and the second axial end face 44 are perpendicular to the axis C20 of the internal gear 20 and are parallel to each other.

  The axial thickness of the outer peripheral ring portion 41 (the axial distance between the first axial end surface 43 and the second axial end surface 44) is W41. That is, the outer peripheral ring portion 41 maintains (restricts) the axial interval between the first external gear 11 and the second external gear 12 at W41. In addition, the outer periphery ring part 41 (the outer periphery thereof) is not in contact with the inner periphery 20A1 of the internal gear main body 20A of the internal gear 20.

  On the other hand, the contact ring portion 42 of the insertion wheel 40 is provided continuously and integrally on the radially inner side of the outer ring portion 41 (formed of the same material as the outer ring portion 41). The contact ring portion 42 is also formed in a substantially rectangular shape in cross section (cross section in FIGS. 1 and 2) passing through the axis C <b> 20 of the internal gear 20. The contact ring portion 42 has a third axial end face 45 and a fourth axial end face 46 (not contacting the first and second external gears 11 and 12) facing each other in the axial direction. The third axial end face 45 and the fourth axial end face 46 are perpendicular to the axis C20 of the internal gear 20 and are parallel to each other.

  The third axial end surface 45 of the insertion wheel 40 faces the first retainer 61B of the first eccentric bearing 61 in the axial direction, and regulates the axial movement of the first retainer 61B in cooperation with the central positioning portion 23. Yes. Similarly, the fourth axial end surface 46 of the insertion wheel 40 is opposed to the second retainer 62B of the second eccentric bearing 62 in the axial direction, and the second retainer 62B is moved in the axial direction in cooperation with the central positioning portion 23. It is regulated.

  The axial thickness of the contact ring portion 42 (the axial distance between the third axial end surface 45 and the fourth axial end surface 46) is W42, which is smaller (thin) than the axial thickness W41 of the outer ring portion 41. That is, the axial thickness W41 of the outer peripheral ring portion 41> the thickness W42 of the contact ring portion 42. In this embodiment, the thickness W42 of the contact ring portion 42 is the same as or substantially the same as the axial thickness W23 of the central positioning portion 23 of the crankshaft 22 (W42 = W23 or W42≈W23).

  The abutting ring portion 42 has a positioned surface 47 that abuts radially on the center positioning portion 23 (the outer periphery thereof) of each crankshaft 22 on the radially inner side. In other words, the insertion wheel 40 circumscribes each central positioning portion 23 of the plurality (three) of the crankshafts 22 via the contact ring portion 42 (positioned surface 47 thereof), and is positioned in the radial direction by this circumscribing. Yes. Specifically, the axis C40 of the insertion wheel 40 is concentric with the axis C20 of the internal gear 20 (= the axis C31 of the first and second carriers 31, 32, C32 = the axis C35 of the output shaft 35). In this state, it is positioned in the radial direction.

  The cross-sectional shape of the insertion ring 40 (the shape in the cross section passing through the axis C20 of the internal gear 20) is axisymmetric with respect to the axial center line P1 of the outer peripheral ring portion 41. Further, the cross-sectional shape of the insertion wheel 40 is point-symmetric with respect to a point Q1 (see FIG. 1) where the axial center line P1 intersects the axis C20 of the internal gear 20.

  The insert wheel 40 is made of resin in this embodiment. Although it may be made of metal, a metal insertion wheel is not necessarily preferable because the contact pressure with the center positioning portion 23 increases due to its own weight, and the progress of wear may be accelerated. .

  In the present embodiment, the positioned surface 47 (radius R47) of the abutting ring portion 42 of the insertion wheel 40 is on the radially outer side than the radially outermost portion 33M of the three carrier pins 33. In other words, the insertion wheel 40 does not overlap the carrier pin 33 when viewed from the axial direction, and does not contact the carrier pin 33 at all.

  Further, the radially outermost portion 11BM of the three first carrier pin holes 11B of the first external gear 11 is located on the radially outer side of the positioned surface 47 of the contact ring portion 42 of the insertion wheel 40. Yes. That is, the first carrier pin hole 11B of the first external gear 11 partially overlaps the contact ring portion 42 of the insertion wheel 40 when viewed from the axial direction (three double hatched portions in FIG. 3). reference).

  However, the radially outermost portion 11BM of the three first carrier pin holes 11B of the first external gear 11 (even if the first external gear 11 swings) It is always radially inward from the inner periphery 41A (radius R41A). That is, the first carrier pin hole 11B does not overlap with the outer peripheral ring portion 41 when viewed from the axial direction.

  Although not shown, the same applies to the second external gear 12 side, and the second carrier pin hole 12B overlaps with the contact ring portion 42 of the insertion ring 40 when viewed from the axial direction, and the outer periphery. It does not overlap with the ring portion 41 (even if the second external gear 12 swings).

  Next, the operation of the eccentric oscillating speed reduction device G1 will be described.

  When the input shaft 48 rotates, the input pinion 49 incorporated in the input shaft 48 rotates. The input pinion 49 meshes simultaneously with the three sorting gears 39. Therefore, the rotation of the input pinion 49 causes the three sorting gears 39 to rotate in the same direction at the same rotational speed. As each sorting gear 39 rotates, the three crankshafts 22 rotate in the same direction at the same rotational speed, and the first eccentric body 51 and the second eccentric body 52 of each crankshaft 22 are 180 degrees eccentric. Rotate eccentrically in phase.

  As a result, the first external gear 11 externally fitted to the first eccentric body 51 of each crankshaft 22 via the first eccentric body bearing 61 swings and rotates, and the second eccentric body 52 of each crankshaft 22 is rotated. The second external gear 12 that is externally fitted through the second eccentric body bearing 62 rotates and rotates.

  The first external gear 11 and the second external gear 12 are internally meshed with the internal gear 20, and the number of teeth of the internal gear 20 is the first external gear 11 and the second external gear. 2 more than 12 teeth. Therefore, every time the first external gear 11 and the second external gear 12 swing and rotate once (each time the crankshaft 22 rotates once), the first external gear 11 and the second external gear 12. Rotates relative to the internal gear 20 integrated with the casing 21 by a difference in the number of teeth (for two teeth).

  Each crankshaft 22 revolves around the axis C <b> 20 of the internal gear 20 by the rotation of the first external gear 11 and the second external gear 12. Due to the revolution of the crankshaft 22, the first carrier 31 and the second carrier 32 that support the crankshaft 22 rotate integrally as one large carrier 30 via the carrier pin 33. In the speed reduction device G1, since the second carrier 32 is integrated with the output shaft 35, the output shaft 35 is rotated by the rotation of the second carrier 32.

  When this series of deceleration actions is performed, the axial interval between the first external gear 11 and the second external gear 12 is regulated by the insertion ring 40. That is, the first external gear 11 and the second external gear 12 are maintained at a distance corresponding to the axial thickness W41 of the outer peripheral ring portion 41 of the insertion ring 40. Further, the positioning surface 47 of the contact ring portion 42 of the insert wheel 40 is in contact (outside contact) with each central positioning portion 23 of the crankshaft 22. Therefore, the insertion wheel 40 is positioned in the radial direction by circumscribing the center positioning portion 23. As a result, the shaft center C40 of the insertion wheel 40 is maintained concentric with the shaft center C20 of the internal gear 20.

  Here, if the carrier 30 is twisted, the meshing property between the first and second external gears 11 and 12 and the internal gear 20 and the sliding property of each part are deteriorated, so that the operation efficiency is reduced and the operation noise is reduced. It becomes a factor to increase. In order to increase the torsional rigidity of the carrier 30, it is effective to increase the thickness of the carrier pin 33 or to make the formation position of the carrier pin 33 more outward in the radial direction. However, in the past, there was a problem that it was difficult to make the carrier pin thicker or make the formation position of the carrier pin more outward in the radial direction because the insertion ring was externally fitted to each carrier pin. .

  In order to make the present embodiment easier to understand, first, this conventional problem will be described more specifically.

  In the conventional configuration (the insert wheel is fitted on each carrier pin), the inner diameter of the insert wheel is substantially the same as the outer diameter of the carrier pin (gap fitting). On the other hand, since the carrier pin hole of the external gear is oscillating with respect to the carrier pin whose shaft center is fixed, when the external gear oscillates unless the outer diameter of the insertion ring is sufficiently large, Occasionally, a phenomenon occurs in which a part of the insertion ring is drawn into the carrier pin hole. When this phenomenon occurs, the insertion wheel rubs strongly against the end of the carrier pin hole and wears early.

  In order to avoid this phenomenon, it is necessary to make the outer diameter of the insertion ring large enough to contact the external gear with a sufficient area. In other words, the outer diameter of the insertion ring is set to be sufficiently larger than (the outer diameter of the carrier pin + the eccentric amount of the eccentric body × 2 + the minimum gap between the carrier pin and the carrier pin hole). There must be. However, since the conventional insertion wheel is externally fitted to each carrier pin, it exists around the entire circumference of each carrier pin. Therefore, the increase in the diameter of the insert ring is not limited to the internal gear on the radially outer side of the carrier pin, the center through hole on the radially inner side, or the eccentric bearing of the crankshaft on both circumferential sides. I had to interfere.

  Therefore, conventionally, as a result, without increasing the size of the internal gear 20 (or the casing 21), the thickness of the carrier pin 33 is increased, or the formation position of the carrier pin 33 is shifted more radially outward. In reality, it is extremely difficult to secure a higher torsional rigidity of the carrier pin 33.

  However, according to the present embodiment, the insertion wheel 40 is not fitted around each carrier pin 33, but is assembled in such a manner as to circumscribe the center positioning portion 23 of the crankshaft 22. Therefore, at least the space on the inner side in the radial direction and the both sides in the circumferential direction of the carrier pin 33 is not occupied by the insertion wheel 40.

  Further, the insertion wheel 40 is greatly different in diameter from the first and second carrier pin holes 11B and 12B, and in particular, the axial end surfaces 11F and 12F of the first and second external gears 11 and 12 and the circumferential direction. Is in wide contact. Therefore, the phenomenon that the insertion wheel 40 is pulled into the first and second carrier pin holes 11B and 12B is extremely unlikely to occur.

  For this reason, a larger diameter (thickness) or cross-sectional area of the carrier pin 33 is secured with respect to the internal gear 20 (or the casing 21) of a predetermined size, and the formation position of the carrier pin 33 is more radial. A design that shifts outward can be realized more easily.

  Therefore, the torsional rigidity of the carrier 30 can be further increased without increasing the overall size of the reduction gear G1, and the basic driving performance such as improvement of driving efficiency or reduction of driving noise can be further improved. it can.

  Further, since only one insertion ring 40 is required, the number of parts can be reduced (compared to a structure in which a plurality of insertion rings are externally fitted to each carrier pin), and the assembly process can be simplified.

  In this embodiment, the distance R23 from the axis C22 of the crankshaft 22 to the outer periphery of the center positioning portion 23 is the distance from the axis C22 of the crankshaft 22 to the outer periphery of the maximum eccentric portion 51M of the first eccentric body 51. (Dimension) It is the same as L51M (R23 = L51M). The same applies to the second eccentric body 52 side (R23 = distance L52M from the axis C22 of the crankshaft 22 to the outer periphery of the maximum eccentric portion 52M of the second eccentric body 52). For this reason, when assembling the insert wheel 40, the insert wheel 40 does not interfere with the first eccentric body 51 and the second eccentric body 52, and the insert wheel 40 can be easily circumscribed to the central positioning portion 23. it can. Further, the axial positioning of the first and second retainers 61B and 62B of the first and second eccentric bearings 61 and 62 can be restricted by the central positioning portion 23 formed in this size.

  Further, in this embodiment, the insertion ring 40 is provided on the radially outer side of the outer peripheral ring portion 41 and the outer peripheral ring portion 41 that contacts the first external gear 11 and the second external gear 12 in the axial direction. A contact ring portion 42 is provided. The contact ring portion 42 has an axial thickness W 42 smaller than the axial thickness W 41 of the outer peripheral ring portion 41, and is in contact with the central positioning portion 23 of the crankshaft 22 in the radial direction.

  Therefore, the outer circumferential ring portion 41 of the insertion wheel 40 regulates the axial interval between the first external gear 11 and the second external gear 12 (without interfering with the first and second eccentric body bearings 61 and 62). it can. Further, the insert wheel 40 is circumscribed by the center positioning portions 23 of the plurality of crankshafts 22 (without interfering with the first and second eccentric bearings 61 and 62) via the contact ring portion 42 of the insert wheel 40. Can be made.

  Further, in this embodiment, the first and second carrier pin holes 11B and 12B overlap the contact ring portion 42 of the insertion wheel 40 and do not overlap the outer ring portion 41 when viewed from the axial direction. It is said that. That is, the insertion wheel 40 and the first and second carrier pin holes 11B and 12B overlap only at a portion where double hatching is performed in FIG. 3 when viewed from the axial direction. However, this overlapping portion corresponds to the abutment ring portion 42 of the insertion ring 40, and the axial thickness W42 of the corresponding contact ring portion 42 is set smaller than the axial thickness W41 of the outer peripheral ring portion 41. Therefore, this portion does not come into contact with the first and second external gears 11 and 12. Therefore, no interference occurs between the insertion wheel 40 and the first and second carrier pin holes 11B and 12B.

  4 and 5 show examples of other embodiments of the present invention.

  Also in the present embodiment, the crankshaft 122 includes a central positioning portion 123 having an axis C123 that coincides with the axis C122 of the crankshaft 122 between the first eccentric body 151 and the second eccentric body 152. However, the insert wheel 140 is positioned in the radial direction by being inscribed (not circumscribed) at each central positioning portion 123 of the plurality (three) of the crankshafts 122.

  In the previous embodiment, the distance R23 from the axis C22 of the crankshaft 22 to the outer periphery of the center positioning portion 23 is from the axis C22 of the crankshaft 22 to the outer periphery of the maximum eccentric portion 51M of the first eccentric body 51. It was set to be the same as the distance L51M. However, in this embodiment, the distance R123 from the axis C122 of the crankshaft 122 to the outer periphery of the center positioning portion 123 is the distance from the axis C122 of the crankshaft 122 to the outer periphery of the maximum eccentric portion 151M of the first eccentric body 151. It is set larger than L151M (R123> L151M).

  As exemplified in these two embodiments, the distance from the axis of the crankshaft to the outer periphery of the central positioning portion is from the axis of the crankshaft to the outer periphery of the maximum eccentric portion of the first and second eccentric bodies. It is better to set the distance to “over”. Thereby, regardless of the presence of the first and second eccentric bodies, the insertion wheel can be easily incorporated into the central positioning portion. In addition, even if the insertion wheel is smaller than the distance from the axial center of the crankshaft to the outer periphery of the maximum eccentric portion of the first and second eccentric bodies, it can be incorporated if it is larger than the radius of the first and second eccentric bodies. There is a case.

  In this type of eccentric oscillating type speed reducer, a plurality of speed reducers having different speed reduction ratios are often provided as a “series”. Usually, since the reduction gears with different reduction ratios have different amounts of eccentricity of the first and second eccentric bodies, the distances from the axial center of the crankshaft to the outer periphery of the maximum eccentric portion of the first and second eccentric bodies are also different. . Therefore, in actual design, from the speed reducer in the series, the speed reducer with the longest distance from the crankshaft axis to the maximum eccentric part is used as a reference, from the crankshaft axis to the outer periphery of the central positioning part. It is recommended to set the distances in common. Thereby, the outer diameter of the central positioning part of all the reduction gears in the series can be set to a distance “more than” from the axial center of the crankshaft to the outer periphery of the maximum eccentric part of the first and second eccentric bodies. As a result, a single gear wheel can be shared by all the reduction gears having different speed reduction ratios, and the design of the gear wheel and the ease of inventory management can be realized.

  The insert wheel 140 according to the present embodiment will be described more specifically. The insert wheel 140 includes a disk-shaped central disk portion 141 that is in axial contact with the first external gear 111 and the second external gear 112, and And a contact ring portion 142 provided on the outer side in the radial direction of the central disk portion 141.

  The axial thickness of the central disk portion 141 of the insert wheel 140 is W141. That is, the central disk portion 141 maintains (restricts) the axial interval between the first external gear 111 and the second external gear 112 at W141.

  On the other hand, the contact ring portion 142 of the insertion wheel 140 is provided integrally and continuously on the radially outer side of the central disc portion 141 (formed of the same material as the central disc portion 141). The axial thickness of the contact ring portion 142 is W142, which is smaller (thin) than the axial thickness W141 of the central disk portion 141. The axial thickness W142 of the contact ring portion 142 is the same as the axial thickness W123 of the central positioning portion 123 of the crankshaft 122 (W142 = W123).

  The contact ring portion 142 has a positioned surface 147 (radius R147) that radially contacts the center positioning portion 123 (the outer periphery thereof) of each crankshaft 122 on the outer periphery. That is, the insert wheel 140 is inscribed in each of the central positioning portions 123 of the plurality (three) of the crankshafts 22 through the contact ring portion 142 (positioned surface 147 thereof), and is positioned in the radial direction by this inscription. Has been. Specifically, the shaft center C140 of the insertion wheel 140 is positioned in the radial direction in a state of being concentric with the shaft center C120 of the internal gear 120.

  The cross-sectional shape of the insertion wheel 140 (the shape in the cross section passing through the axis C120 of the internal gear 120) is line symmetric with respect to the axial center line P101 of the central disk portion 141. Further, the insertion ring 140 is point-symmetric with respect to a point Q101 where the axial center line P101 intersects with the axis C120 of the internal gear 120.

  In the present embodiment, a configuration in which a higher rigidity characteristic is obtained with respect to the carrier pin 133 is employed by more positively utilizing the high degree of freedom of the configuration of the carrier pin 133.

  For example, the shape of the cross section perpendicular to the axis of the carrier pin 133 (the cross section of FIG. 5) is a non-circular shape. Specifically, the cross-sectional shape of the carrier pin 133 is a triangle close to a trapezoid whose sides are rounded, and the cross-sectional shape in which the circumferential thickness on the radially outer side is larger than the circular cross-sectional shape. It is as. Thus, even if the distance RC138 from the axis C120 of the internal gear 120 to the axis C138 of the connecting bolt 138 of the carrier pin 133 is the same, the center of gravity of the cross section of the carrier pin 133 from the axis C120 of the internal gear 120 The distance L133G to 133G can be further increased (L133G> RC138), and the substantial formation position of the carrier pin 133 can be shifted more radially outward.

  Further, in the present embodiment, the carrier pin 133 protrudes directly and integrally from the first carrier 131 (configured by the same member as the first carrier 131). The carrier pin 133 has an outer periphery 133A inclined with respect to the axis C133 of the carrier pin 133, and the cross section perpendicular to the axis is closer to the first carrier 131 than to the second carrier 132. The shape gradually increases. Further, the carrier pin 133 has a stepped portion 133B in the vicinity of the first carrier 131, and the first carrier 131 side in the axial direction has a larger sectional area with the stepped portion 133B as a boundary. As a result, the strength of the protruding root portion on the first carrier 131 side of the carrier pin 133 protruding from the first carrier 131 side in a cantilever state is further increased.

  Due to these synergistic actions, the carrier pin 133 has a higher torsional rigidity than the carrier pin 33 having a simple circular cross section as in the previous embodiment, for example.

  The shapes of the first carrier pin hole 111B and the second carrier pin hole 112B are substantially similar to the cross-sectional shape perpendicular to the axis of the carrier pin 133. Even if the first external gear 111 and the second external gear 112 swing eccentrically, the carrier pin 133 does not contact the first carrier pin hole 111B of the first external gear 111 and the second external gear 112. The second carrier pin hole 112B does not contact.

  In this embodiment, the first and second eccentric body bearings 161 and 162 are provided with the first and second inner rings 161C and 162C, and the first and second inner rings 161C are provided by the central positioning portion 123. , 162C is restricted from moving in the axial direction. The insertion wheel 140 is not particularly restricted in the axial movement of the first and second retainers 161B and 162B of the first and second eccentric bearings 161 and 162. However, a configuration may be adopted in which axial movement of the retainers and the like of the first and second eccentric body bearings is regulated by the center positioning portion and the insertion wheel (or by the center positioning portion and the insertion wheel).

  Further, in this embodiment, the insertion wheel 140 and the first and second carrier pin holes 111B and 112B and the first and second eccentric body bearing holes 111E and 112E are double-hatched in FIG. It overlaps in the given part. However, this portion corresponds to the contact ring portion 142 of the insertion ring 140, and the axial thickness W142 of the contact ring portion 142 is set smaller than the axial thickness W141 of the central disk portion 141. There is no interference between the ring 140 and the first and second carrier pin holes 111B and 112B or the first and second eccentric body bearing holes 111E and 112E.

  Since other configurations are the same as those of the previous embodiment, the same reference numerals are given to the same or functionally the same parts as those of the previous embodiment, and the duplicate description is omitted. .

  In addition, various variations can be considered for the configuration of the insertion ring, and the configuration is not limited to the above configuration example. For example, if there is no space interference with other members or the like, a rectangular insertion ring having a simple cross section including the axis of the internal gear may be employed.

  Further, the configurations of the first carrier, the second carrier, and the carrier pin (connection member) are not limited to the above configuration. For example, the carrier pin may be composed of separate members for both the first carrier and the second carrier.

  Furthermore, in the present invention, it is always required to make the thickness of the carrier pin thicker than in the past, or to shift the formation pitch circle of the carrier pin more radially outward than in the past. It is not a thing. For example, when importance is attached to the compactness of the entire apparatus, the rigidity (configuration) of the carrier pin is the same as the conventional one, and the space outside the radial direction of the carrier pin hole is made smaller than the conventional one. The first and second external gears and the internal gear may be designed to be smaller than the conventional one. In other words, the present invention does not necessarily use the merit of the invention in the direction of “improvement” of the torsional rigidity of the carrier, but in the direction of realizing a reduction gear having the same torsional rigidity in a more compact size. May be.

G1 ... Deceleration device 11 ... First external gear 12 ... Second external gear 20 ... Internal gear 22 ... Crankshaft 23 ... Center positioning part 31 ... First carrier 32 ... Second carrier 33 ... Carrier pin (connection member)
40 ... Insert wheel 51 ... First eccentric body 52 ... Second eccentric body C22 ... Center axis of crankshaft C23 ... Center axis of central positioning portion

Claims (6)

A first external gear, a second external gear arranged in an axial direction with the first external gear, an internal gear meshing with the first external gear and the second external gear, A plurality of crankshafts arranged at positions offset from the axis of the internal gear and swinging and rotating the first external gear and the second external gear, and arranged on one axial side of the first external gear. A first carrier, a second carrier disposed on the other axial side of the second external gear, a connecting member for connecting the first carrier and the second carrier, and the first external gear, An eccentric oscillating type speed reducer in which the first external gear and the second external gear do not contact in the axial direction, and an insertion ring disposed between the second external gears,
The crankshaft includes a first eccentric body on which the first external gear is fitted, a second eccentric body on which the second external gear is fitted, and the first eccentric body and the second eccentric body. A center positioning portion having an axis that is provided between and coincident with the axis of the crankshaft,
The eccentric oscillating speed reduction device is characterized in that the insertion wheel is positioned in a radial direction by being inscribed or circumscribed to each central positioning portion of the plurality of crankshafts. In claim 1,
The distance from the axial center of the crankshaft to the outer periphery of the central positioning portion is equal to or greater than the distance from the axial center of the crankshaft to the outer periphery of the maximum eccentric portion of the first eccentric body. Mold speed reducer. In claim 1 or 2,
The insertion wheel is an insertion wheel circumscribing each central positioning portion of the plurality of crankshafts,
The insertion ring includes an outer ring portion that is in axial contact with the first external gear and the second external gear;
An abutting ring portion that is provided on the radially inner side of the outer peripheral ring portion, has an axial thickness smaller than that of the outer peripheral ring portion, and is in radial contact with each central positioning portion of the plurality of crankshafts. An eccentric oscillating speed reduction device. In claim 3,
The first external gear has a through hole through which the connecting member penetrates with a gap,
The eccentric oscillating speed reduction device, wherein the through hole overlaps the contact ring portion of the insertion wheel and does not overlap the outer ring portion when viewed from the axial direction. In claim 1 or 2,
The insertion wheel is an insertion wheel inscribed in each central positioning portion of the plurality of crankshafts,
The insertion wheel includes a central disk portion that is in axial contact with the first external gear and the second external gear,
A contact ring portion provided on a radially outer side of the central positioning portion, having an axial thickness smaller than that of the central disk portion and abutting in a radial direction on each of the central positioning portions of the plurality of crankshafts. An eccentric oscillating speed reduction device. In any one of Claims 1-5,
A first eccentric body bearing disposed between the first eccentric body and the first external gear; a second eccentric body bearing disposed between the second eccentric body and the second external gear; Have
The eccentric oscillating type speed reducer characterized in that axial movement of the first eccentric body bearing and the second eccentric body bearing is restricted by the central positioning portion or the insertion wheel.

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