JP2014092209A - Planetary gear reduction device and fabrication method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planetary gear reduction device which reinforces a fatigue strength of a root part with a flange body of a pin member, in the planetary gear reduction device in which the pin member penetrating an outer tooth gear is integrally protruded and formed from the flange body.SOLUTION: A planetary gear reduction device G1 includes: an external tooth gear 11; an internal tooth gear 16 which is inscribed and meshes with the external tooth gear 11; a first flange body 41 arranged on a lateral part in the axial direction of the external tooth gear 11; and an inner pin (pin member) 54 which are integrally protruded and formed in the axial direction from the first flange body 41 and penetrate the external tooth gear 11 and an inner roller 58 and, therein, plastic processing is performed on a root part 54 P1 of the pin member 54.

Description

  The present invention relates to a planetary gear reduction device and a manufacturing method thereof.

  Patent Document 1 discloses a planetary gear reduction device.

  This planetary gear reduction device includes an external gear that is a planetary gear, and an internal gear that is internally meshed with the external gear. A flange body is disposed on the axial side portion of the external gear. From the flange body, a pin member is integrally projected and formed to constitute a single flange body unit. The pin member penetrates the external gear in the axial direction, and transmits the rotation component of the external gear to the flange body. The flange body is supported by the casing and is rotatable around the axis of the internal gear.

  The flange body rotates in synchronization with the rotation component of the external gear transmitted through the pin member, and functions as an output member of the planetary gear reduction device.

Japanese Patent Laying-Open No. 2006-263878 (FIGS. 2 and 3)

  As described above, in the planetary gear reduction device in which the pin member penetrating the external gear is integrated with the flange body arranged on the axial side portion of the external gear, the flange of the pin member is particularly suitable. There is a problem that bending stress tends to concentrate on the root part with the body, and fatigue strength (strength against the phenomenon that the member breaks due to repeated application even if it is less than the breaking load) tends to be lowered.

  The present invention has been made to solve such a problem, and in a planetary gear reduction device in which a pin member penetrating an external gear is integrally formed to protrude from a flange body, The task is to further increase the fatigue strength of the root portion with the flange body.

  The present invention includes an external gear, an internal gear in which the external gear meshes internally, a flange body disposed on an axial side portion of the external gear, and an axial direction integrally from the flange body. A planetary gear reduction device comprising a pin member protruding and penetrating through an external gear, wherein the above-mentioned problems are solved by adopting a configuration in which the base portion of the pin member is plastically processed It is.

  In the present invention, plastic working is performed on the root portion of the pin member with the flange body.

  Thereby, a strong residual compressive stress can be generated in the root portion of the pin member by the plastic working, and the bending stress concentrated on the root portion is relieved (cancelled), so that the fatigue strength can be further enhanced. it can.

  In the planetary gear reduction device in which the pin member penetrating the external gear is integrally formed to protrude from the flange body, the fatigue strength of the root portion of the pin member with the flange body can be further increased.

Sectional drawing which shows the whole structure of the planetary gear speed reducer to which an example of embodiment of this invention was applied. 1 is a front view partially including an enlarged cross section of the flange body unit 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 showing an overall configuration of a planetary gear speed reduction device to which an example of an embodiment of the present invention is applied, and FIG. 2 is a front view partially including an enlarged cross section of the flange body unit of FIG. .

  This planetary gear reduction device G1 is a planetary gear reduction device called an eccentric oscillating type.

  The input shaft 18 of the planetary gear reduction device G1 is a hollow shaft having a hollow portion 18A, and is arranged at the position of the axis O1 of the internal gear 16 of the planetary gear reduction device G1. A spline 18 </ b> B for receiving power from a drive source side member (not shown) is formed at the end of the input shaft 18. Three eccentric bodies 21 are integrally formed along the axial direction on the outer periphery of the input shaft 18. The outer periphery of each eccentric body 21 is eccentric with an eccentric phase difference of 120 degrees with respect to the axis of the input shaft 18.

  Three external gears 11 are incorporated on the outer periphery of the eccentric body 21 via roller bearings 31. Each external gear 11 is in mesh with the internal gear 16. The reason why the external gear 11 is incorporated in three rows is that the increase in transmission capacity and the reduction in vibration and noise by shifting the eccentric phase are intended. The configuration of each row is the same except that the eccentric phase is different.

  In this embodiment, the internal gear 16 is an internal gear main body 16A integrated with the casing 36, and is rotatably supported by the internal gear main body 16A, and the external gear constituting the internal teeth of the internal gear 16 is provided. It consists of pins 16B. The number of internal teeth of the internal gear 16 (the number of external pins 16B) is slightly larger (only 1 in this example) than the number of external teeth of the external gear 11.

  First and second flange bodies 41 and 42 are arranged on both axial sides of the external gear 11. The first and second flange bodies 41 and 42 are rotatably supported by the casing 36 via first and second angular ball bearings 44 and 46.

  The outer circumferences of the first and second flange bodies 41 and 42 also serve as inner rings of the first and second angular ball bearings 44 and 46, respectively, and rolling elements 44A and 46A of the first and second angular ball bearings 44 and 46, respectively. The rolling surfaces 41A and 42A are configured. Further, on the outer periphery of the first flange body 41, a sliding surface 41B of the oil seal 48 is formed adjacent to the rolling surface 41A of the rolling element 44A of the first angular ball bearing 44.

  The input shaft 18 is supported via ball bearings 51 and 52 on the radially inner side of the first and second flange bodies 41 and 42.

  Of the first and second flange bodies 41, 42, a cylindrical inner pin 54 (pin member) extends from the first flange body 41 on the left side of the drawing to the side surface 41G of the base portion 41D in the axial direction. A plurality (six in this embodiment) are integrally formed to form a single flange body unit 56.

  In this embodiment, hot forging or the like conventionally performed to manufacture a base member (flange body base material to be described later) of the flange body unit 56 at the root portion 54P1 of the inner pin 54 with the first flange body 41. Apart from the plastic processing (after carburizing and heat treatment of the base member), plastic processing by shot peening is performed. The plastic working of the root portion 54P1 will be described in detail later.

  The inner pin 54 passes through a through hole 11 </ b> A formed in the external gear 11. An inner roller 58 is rotatably covered on the inner pin 54 as a sliding promotion member. The inner roller 58 is restricted from moving in the axial direction by the side surfaces 41G and 42G of the pedestal portions 41D and 42D of the first and second flange bodies 41 and 42, respectively. That is, the inner roller 58 covers the inner pin 54 almost completely, including the root portion 54P1 of the inner pin 54.

  The inner pin 54 has a tip portion fitted into a bottomed recess 42C formed in the second flange body 42, and the first flange body 41 and the second flange together with the bolt 60 inserted from the axially opposite first flange body side. The flange body 42 is connected.

  The outer diameter d1 of the inner roller 58 covered on the inner pin 54 is formed to be smaller than the inner diameter D1 of the through hole 11A by an amount corresponding to twice the eccentric amount of the eccentric body 21. As a result, the inner pin 54 covered by the inner roller 58 is always (via the inner roller 58) on the side opposite to the eccentric side of the through hole 11A of the outer gear 11 while allowing the outer gear 11 to swing. The state in contact with the inner periphery is maintained.

  As shown in FIG. 2, a portion where the inner pin 54 rises from the first flange body 41, that is, a root portion 54P1 on the first flange body 41 side of the inner pin 54 is intentionally formed in an arcuate recess 54A. Is formed.

  This is because the inner pin 54 is integrally raised at an angle of 90 degrees from the first flange body 41, so that the root portion 54P1 of the inner pin 54 is locally dimensioned due to a processing error or insufficient processing. This is because the smooth rotation of the inner roller 58 is hindered when there is a portion where the increase is made.

  On the other hand, on the second flange body 42 side, the inner pin 54 is fitted into the bottomed recess 42C while maintaining a uniform outer diameter d1 as a separate member from the second flange body 42. There is no risk of processing errors that hinder the rotation of 58 or increase in dimensions due to insufficient processing. Therefore, the arc-shaped concave portion (54A) formed in the root portion 54P1 on the first flange body 41 side is not particularly formed in the root portion 54P2 on the second flange body 42 side of the inner pin 54.

  In this embodiment, of the first and second flange bodies 41, 42, the driven member of the counterpart machine (not shown) is connected to the first flange body 41 via a tap hole formed in the first flange body 41. It is connected to the side surface 41H.

  Next, the operation of the planetary gear reduction device G1 will be described.

  First, the operation of power transmission will be briefly described.

  When the power from the drive source is transmitted to the input shaft 18 via the spline 18B, the three eccentric bodies 21 integrated with the input shaft 18 rotate eccentrically with a phase difference of 120 degrees. As a result, the three external gears 11 oscillate with a phase difference of 120 degrees via the roller bearing 31.

  Since each external gear 11 is internally meshed with the internal gear 16, when each external gear 11 swings, the meshing position of the external gear 11 sequentially shifts with respect to the internal gear 16. Arise. Each time the input shaft 18 rotates once, the external gear 11 rotates by the number of teeth difference (one tooth) with respect to the internal gear 16 in the fixed state.

  Due to the rotation of the external gear 11, the inner pin 54 and the inner roller 58 passing through the external gear 11 revolve around the axis of the internal gear 16, and the first and second flange bodies 41, 42 are rotated. Transmitted as rotation. When the first and second flange bodies 41 and 42 rotate, the driven body of the counterpart machine connected using the tap holes of the first flange body 41 rotates.

  Here, in particular, the operation of the flange body unit 56 will be described together with the description of the method for manufacturing the flange body unit 56.

  In the present embodiment, plastic working by shot peening is performed on the root portion 54P1 of the inner pin 54 (rise from the first flange body 41) in the flange body unit 56.

  Specifically, a flange body base material (a member serving as a base of the flange body unit 56) from which the inner pin 54 protrudes integrally from the first flange body 41 is replaced with a steel material (for example, SCM420 (H)). And manufactured by hot forging. After hot forging, carburizing and quenching (heat treatment) is performed. In this embodiment, after carburizing and heat treatment, before the finishing process is performed, the base part (54P1) of the inner pin (54) of the flange base material is subjected to plastic working by shot peening.

  When the flange base material itself (the overall shape of the flange body) is manufactured by plastic working such as hot forging as in this embodiment, the entire flange body is formed to form the overall shape of the flange body. The plastic processing to be applied is not included in the concept of “plastic processing is applied to the base portion of the pin member” in the present invention. That is, if it says in this embodiment, the plastic processing (shot peening) performed only to a part of flange body including the root part of a pin member is "plastic processing is given to the root part of a pin member in this invention. Is equivalent to the concept of “

  Further, if another view is taken, in this embodiment, heat treatment is performed after plastic working such as hot forging for manufacturing the flange base material itself, and then the root portion of the pin member. Since the shot peening is performed, “after the step of forming the overall shape of the flange body base material, plastic processing applied to the root portion of the pin member” or “after the heat treatment of the flange body base material It can also be said that “plastic processing applied to the base portion of the pin member” corresponds to the concept “plastic processing is applied to the base portion of the pin member” in the present invention.

  The plastic working applied to the base portion of the pin member according to the present invention may be performed before finishing or after finishing.

  In this embodiment, after carburizing and heat treatment and before finishing, the base portion (54P1) of the inner pin (54) of the flange base material is subjected to plastic working by shot peening.

  In this embodiment, φ0.6 mm, Hv600 hardness particles are projected as a shot peening projection material. In shot peening, it is generally effective to project at a projection angle of 90 degrees with respect to the projection plane. However, in this embodiment, the shot peening is intentionally performed at 15 to 30 degrees from a plane perpendicular to the axis of the inner pin 54. Projection is performed at a projection angle α tilted within a range of. This is because, when shot peening is applied to the root portion 54P1 of the inner pin 54 configured as in the present embodiment, the projection is slightly inclined rather than projecting at a projection angle of 90 degrees with respect to the axis of the inner pin 54. This is because it has been confirmed by experiments by the inventors that a larger amount of residual stress can be generated as a result of projecting from an angle. This will be discussed later.

  Shot peening is performed only at the position corresponding to the root portion (54P1) of the inner pin (54) of the flange base material. For example, it is performed on the outer peripheral surface other than the root portion (54P1) of the inner pin (54) (the sliding surface 41A with the inner roller 58: the surface that becomes the sliding surface with the external gear when there is no inner roller). Absent. Further, the second flange body 42 side does not even perform plastic working of the root portion (54P2). This is because the second flange body 42 and the inner pin 54 are separated from each other on the second flange body 42 side, and “stress concentration due to being integral” occurs as in the first flange body 41 side. This is because it is difficult.

  Furthermore, in this embodiment, shot peening is not performed on the position corresponding to the radially inner portion 54F of the planetary gear reduction device G1 of the inner pin (54) of the flange base material.

  In the present embodiment, a range of ± 90 degrees around the portion of the outer peripheral surface 54S of the inner pin 54 that is the smallest distance from the axis O1 is the radially inner portion 54F, but is not limited thereto. The range may be larger or smaller than ± 90 degrees. That is, it is only necessary that shot peening is not performed in a certain range including a portion having a minimum distance from the axis O1 on the outer peripheral surface 54S of the inner pin 54.

  The reason is as follows.

  As described above, when the external gear 11 is oscillating, the through hole 11A of the external gear 11 has an inner pin 54 (specifically, in a direction opposite to the direction in which the external gear 11 is eccentric). The inner roller 58 is covered with the inner pin 54: the same applies hereinafter). In other words, the through-hole 11A of the external gear 11 is in contact with the vicinity of the radially outer portion of the planetary gear reduction device G1 of the inner pin 54, regardless of the direction of the external gear 11 in any direction. . When the circumferential position of the inner pin 54 is moved along with the rotation of the external gear 11, the position where the maximum load is applied to the inner pin 54 deviates from the maximum eccentric direction. For example, at the time of forward rotation and reverse rotation, the inner pin 54 is an external gear at the radially outer portion 54E of the planetary gear reduction device G1 (the portion located outside the pitch circle r1 of the inner pin 54). It can be said that the torque by rotation is received from 11 and the torque is transmitted to the first and second flange bodies 41, 42. Therefore, the radially inner portion 54F of the planetary gear reduction device G1 of the inner pin 54 is unlikely to be a problem in terms of load. Therefore, even if shot peening is performed only on the radially outer portion 54E of the planetary gear reduction device G1 of the inner pin 54, the purpose of the shot peening can be substantially achieved. On the other hand, by preventing shot peening from being performed on the radially inner portion 54F of the planetary gear reduction device G1, (as compared with the case where shot peening is performed over the entire circumference of the root portion 54P1 of the inner pin 54). It is possible to reduce the processing cost and the processing time.

  In this embodiment, after performing plastic working by shot peening, finishing is performed. The finishing includes machining of the outer peripheral surface 54S of the inner pin 54, machining of the arc-shaped recess 54A, machining of the rolling surface 41A of the first angular ball bearing 44, machining of the sliding surface 41B of the oil seal 48, and the like. It is. Since finish processing is performed after shot peening, the portion other than the root portion 54P1 of the outer peripheral surface 54S of the inner pin 54, the rolling surface 41A of the angular ball bearing 51, and the sliding surface 41B of the oil seal 48 are used during shot peening. Eliminates the time and effort required for careful masking. However, the order of shot peening (plastic working) → finishing is not an essential order and may be reversed. That is, carburizing, heat treatment → finishing → shot peening (plastic working) may be performed in this order.

  In the present embodiment, in particular, since the arc-shaped recess 54A is formed in the root portion 54P1 of the inner pin 54, when the power accompanying the rotation of the external gear 11 is transmitted to the inner pin 54, structurally, In particular, bending stress tends to concentrate on the recess 54A. However, in this embodiment, since the flange body unit 56 of the planetary gear reduction device G1 is manufactured in this way, an appropriate residual stress can be generated in the root portion 54P1 of the inner pin 54, and the fatigue strength can be increased. It can be effectively enhanced.

  In the present embodiment, the inner roller 58 is positioned on the side surface 41G of the first flange body 41, and the end surface of the inner roller 58 is in sliding contact with the side surface 41G of the first flange body 41. As a secondary effect of plastic working of the base portion 54P1, the “sliding contact portion of the inner roller 58 of the side surface 41B of the first flange body 41 (adjacent to the base portion 54P1)” An increase can also be expected.

  In the present embodiment, since the processing by shot peening is adopted as a specific means of plastic processing applied to the root portion 54P1 of the inner pin 54, plastic processing can be performed easily and inexpensively. Moreover, since the projection angle of the particles of the shot peening is inclined within a range of 15 to 30 degrees from the plane perpendicular to the axis of the inner pin 54, most of the projected particles are pedestal 41D of the inner pin 54 and its It is possible to prevent scattering by hitting the axial side surface 41G, and efficient projection can be performed. As described above, this has been confirmed by experiments by the inventors.

  In addition, due to the operational characteristics of the eccentric oscillating planetary gear reduction device G1, the shot pin peening is not performed on the radially inner portion 54F of the planetary gear reduction device G1 of the inner pin 54, which is unlikely to be a problem in terms of fatigue strength. Therefore, it is possible to reduce the processing cost and the processing time.

  In the above embodiment, the present invention is applied to the eccentric oscillating planetary gear reduction device G1 in which the eccentric body shaft (input shaft 18) for oscillating the external gear 11 is disposed at the axial center position of the internal gear 16. Had been applied. However, the present invention is not particularly limited to the configuration of the above-described embodiment with respect to the configuration of the planetary gear reduction device G1. In short, the planetary gear reduction device G1 has a flange body on the side portion in the axial direction of the external gear. If the planetary gear reduction device has a configuration in which the pin member penetrating the gear is integrally formed so as to protrude from the flange body in the axial direction, it can be applied in exactly the same manner. Effects can be obtained.

  For example, in an eccentric oscillating planetary gear speed reducer, a plurality of eccentric body shafts for oscillating external gears are arranged at positions offset from the axis of the internal gear, and the eccentric body shaft itself revolves. Also known is a planetary gear reduction device configured to swing an external gear by the above-described method. In the case of such a planetary gear speed reduction device, flange bodies that support the eccentric body shaft are usually disposed on both axial sides of the external gear, and both flange bodies are connected by carrier pins that pass through the external gear. Configuration is adopted. Therefore, when the carrier pin is integrally formed so as to protrude from the flange body, the present invention can be applied to the base portion of the carrier pin, and similar effects can be obtained.

  Also, a flange body having a configuration basically similar to that of the previous embodiment, in which a part of a plurality of inner pins that transmit power to and from an external gear is arranged on both sides of the external gear. A planetary gear reduction device G1 is also known which is replaced by a carrier pin that is simply connected. Even in the case of such a planetary gear reduction device, with respect to the base portion of the carrier pin that protrudes integrally from the flange body disposed on the axial side portion of the external gear and penetrates the external gear, The present invention can be applied, and similar effects can be obtained.

  Furthermore, not only in an eccentric oscillating planetary gear reduction device in which the external gear oscillates, but also in a simple planetary gear reduction device in which the external gear simply revolves around the sun gear as a planetary gear. However, when a pin member (so-called planetary pin) that integrally penetrates the external gear from the flange body disposed on the axial side portion of the external gear is formed to protrude at the root portion of the pin member On the other hand, the present invention can be applied, and similar effects can be obtained.

  In the present invention, it is not always necessary to have flange bodies on both axial sides of the external gear. For example, the present invention is also applicable to a reduction gear having a structure in which a flange member is provided only on one axial side of an external gear, and a pin member penetrating the external gear from the flange body integrally protrudes (in a cantilever state). can do. Rather, when the pin member is integrally protruded from the flange body in a cantilever manner in this way, in terms of “bending stress”, the flange body is more than the case where the flange body is on both sides in the axial direction of the external gear. Since the situation is severe, it can be said that this is an application situation in which the effects of the present invention can be obtained more remarkably.

  In the above embodiment, in consideration of the action characteristic of the bending stress generated in the eccentric rocking type inner pin (pin member), the root portion of the inner side in the radial direction of the pin member is subjected to plastic working. Was omitted to reduce the processing cost and the processing time. However, there is no particular reason for such operational characteristics, such as a carrier pin that does not transmit power to the through hole of the external gear or a planetary pin of a simple planetary gear reduction device. However, when it is difficult to perform plastic working on the radially inner portion of the planetary gear speed reducer, the plastic working may be omitted for the radially inner portion. That is, the present invention does not necessarily require that the plastic working is always performed over the entire circumference of the root portion of the pin member. On the other hand, it is not prohibited to perform plastic working on portions other than the root portion of the inner pin including the radially inner portion.

  Further, in the previous embodiment, with respect to the projection angle of shot peening, the projection angle inclined in the range of 15 to 30 degrees is more preferable than maintaining the projection angle of 90 degrees with respect to the axis of the pin member. Focusing on the fact that a larger amount of residual stress can be generated as a result, the projection angle was maintained in the above range. However, the proper projection angle range depends on the structure of the projection gun of the device and the particle Since it varies depending on the size, shape, etc., it is not necessarily limited to the above range.

  The shape and material of the shot peening projection material are not limited to the above embodiment. For example, in addition to the one that projects particles as in the above embodiment, it may be a type of shot peening that pokes a wire-like member.

  In the first place, the means for applying plastic working to the root portion of the pin member is not limited to shot peening. In short, any kind of processing method can be adopted as long as it is a processing method in which a stress exceeding the elastic limit is applied to the material to cause a plastic deformation having a residual compressive stress and it is molded into a desired shape without producing chips. . For example, knurling or plastic working by a method of pressing a hard tool may be used.

G1 ... Planetary gear speed reducer 11 ... External gear 11A ... Through hole 16 ... Internal gear 18 ... Input shaft 21 ... Eccentric body 41, 42 ... First and second flange bodies 41A, 42A ... Rolling surfaces 44, 46 ... First and second angular contact ball bearings 54 ... inner pin 56 ... flange body unit 58 ... inner roller

Claims (7)

An external gear, an internal gear with which the external gear meshes internally, a flange body disposed on the axial side of the external gear, and an externally projecting and integrally formed axially projecting from the flange body A planetary gear reduction device comprising a pin member penetrating the toothed gear,
A planetary gear reduction device characterized in that plastic processing is applied to a root portion of the pin member. In claim 1,
The planetary gear reduction device, wherein the plastic processing is processing by shot peening. In claim 1 or 2,
The planetary gear reduction device is characterized in that the plastic working is not performed on a radially inner portion of the planetary gear reduction device of the pin member. An external gear, an internal gear with which the external gear meshes internally, a flange body disposed on the axial side of the external gear, and an externally projecting and integrally formed axially projecting from the flange body A pin member penetrating the tooth gear, and a manufacturing method of a planetary gear reduction device comprising:
Producing a flange body base material in which the pin member integrally projects from the flange body;
And a step of performing plastic working on a root portion of the pin member of the flange body base material. A method for manufacturing a planetary gear reduction device, comprising: In claim 4,
The plastic processing is processing by shot peening. A method for manufacturing a planetary gear reduction device, wherein: In claim 4 or 5,
In the shot peening, a shot projection angle is inclined in a range of 15 to 30 degrees from a plane perpendicular to the axis of the pin member. In any one of Claims 4-6,
A finishing process is performed after the plastic working. A method for manufacturing a planetary gear reduction device, wherein:

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