JPWO2017109876A1 - Decelerator - Google Patents

Abstract

Provided is a reduction gear that realizes a desired reduction ratio while being formed small in the radial direction of an input shaft (42) and an output shaft (43). In a speed reducer (40) provided with a case (41), a speed reduction mechanism (44) for transmitting the rotation of the input shaft (42) to the output shaft (43), the input shaft (42) is provided on the input shaft (42). A tilt bearing (46) that rotatably supports the swing plate (45) around a second rotation center axis (L2) inclined with respect to the first rotation center axis (L1), and an input shaft (42). And a base plate (47) integral with the output shaft (43) disposed rotatably, and a bevel gear (48) with n ≧ 3 teeth provided on one of the swing plate (45) or the base plate (47). And a rolling element support portion (49) having a plurality of support grooves of at most n−1 and having no common divisor other than 1 for n provided on the other side, and inserted into each support groove, A rolling element group (50) composed of a plurality of rolling elements of a maximum of n−1 which is equal to or less than the plurality of support grooves and does not have a common divisor other than 1 with respect to n.

Description

  The present invention provides a reduction gear that is formed small in the radial direction of an input shaft and an output shaft.

  Patent Document 1 discloses a variable valve timing device having a speed reduction mechanism 10 constituted by a first speed reduction mechanism 20 and a second speed reduction mechanism 30. The speed reduction mechanism 10 decelerates the rotation of the output shaft 4 of the electric motor 3 (input shaft of the speed reduction mechanism 10) and transmits it to the camshaft 1 (output shaft of the speed reduction mechanism 10) connected by spline, and is fixed to the housing 5. The camshaft 1 is rotated relative to the sprocket 2.

  Specifically, when the first input shaft 21 (input shaft of the first speed reduction mechanism 20) integrated with the output shaft 4 of the electric motor 3 rotates relative to the housing 5, the eccentric shaft portion 22 becomes the output shaft 4. It rotates eccentrically around the rotation center axis. When the eccentric shaft portion 22 rotates eccentrically once around the rotation center axis of the output shaft 4, the plurality of rollers 24 receive torque from the ball bearings 11 of the eccentric shaft portion 22, respectively, and thereby the teeth of the first internal gear 23. It rolls along 23a (assuming the number of teeth of the first internal gear 23 is na). The plurality of rollers 24 pushes the cage part 26 through the pockets 25 while rolling by one tooth of the teeth 23 a, and the first intermediate shaft 27 integrated with the cage part 26 (the output of the first reduction mechanism 20). The shaft is rotated about 1 / na around the rotation center axis of the output shaft 4.

  The first reduction mechanism 20 includes a second reduction mechanism 30 having the same configuration as the first reduction mechanism 20 having the first intermediate shaft 27 as the second input shaft 31 and the second intermediate shaft 37 as the output shaft. Connected. In the second speed reduction mechanism 30, when the eccentric shaft portion 32 of the second input shaft 31 (first intermediate shaft 27) rotates eccentrically once, the plurality of rollers 34 become the teeth 33 a (tentatively the second second gear 33) of the second internal gear 33. The camshaft 1 splined to the second intermediate shaft 37 and the second intermediate shaft of the retainer portion 36 via the pocket 35 is rolled by rolling along the pocket 35 along the number of teeth of the internal gear 33 nb). Rotate 1 / nb. As a result, the speed reduction mechanism 10 of Patent Document 1 connects the first speed reduction mechanism 20 and the second speed reduction mechanism 30 in series, thereby making one rotation of the output shaft 4 of the electric motor 3 with respect to the housing 5 and the sprocket 2 the camshaft 1. 1 / na × 1 / nb rotation is transmitted after being decelerated.

JP 2010-242595 A

  Since the unevenness of the teeth 23a of the first internal gear 23 and the teeth 33a of the second internal gear 33 of Patent Document 1 are both formed in the radial direction of the first and second internal gears (23, 33), the first The roller 24 of the speed reduction mechanism 20 and the roller 34 of the second speed reduction mechanism 30 reciprocally swing inward or outward in the radial direction when rotating along the teeth 23a and the teeth 33a, respectively. Therefore, in the speed reduction mechanism 10 of Patent Document 1, it is necessary to increase the diameter of the housing 5 in order to secure a space for the rollers 24 and 34 to swing in the radial direction.

  A reduction gear formed large in the radial direction of the input shaft and the output shaft has a problem in that the reduction gear cannot be arranged in a device that does not have an arrangement space with a margin in the radial direction of the reduction gear.

  In view of the above problems, the present invention provides a reduction gear that realizes a desired reduction ratio while being formed small in the radial direction of an input shaft and an output shaft.

  In the speed reducer of the present application, a case, an input shaft that is rotatably supported by the case, and an output shaft that is rotatably supported by the case and coaxial with the input shaft and disposed so as to be relatively rotatable. And a reduction mechanism that decelerates the rotation of the input shaft and transmits it to the output shaft, wherein the reduction mechanism is provided in the circumferential direction of the swing plate and the outer periphery of the input shaft, A tilt bearing for rotatably supporting the swing plate about a second rotation center axis inclined with respect to the first rotation center axis of the shaft; and the input shaft in a state of facing the surface of the swing plate And a base plate which is rotatably supported by the input shaft and integrated with the output shaft, and the surface of the swing plate or the base plate so as to be convex in the axial direction of the first rotation center axis 3 or more provided on one side There is no common divisor other than 1 with respect to n, which is provided on the other side of the surface of the swing plate or the base plate where the bevel gear is not provided. Rolling body support portions having a maximum of n-1 plurality of support grooves, and the plurality of support grooves inserted into the plurality of support grooves and sandwiched between the bevel gear and the rolling body support portions, respectively. And a rolling element group consisting of a plurality of rolling elements of a maximum of n−1 and having no common divisor other than 1 with respect to n.

  (Operation) When the input shaft rotates relative to the case, the swinging plate rotatably supported by the tilt bearing in an inclined state does not rotate relative to the case, and the first rotation center axis line It swings back and forth in the axial direction of the first rotation center axis about the intersection with the second rotation center axis. When the rocking plate reciprocates once in the axial direction of the first rotation center axis by rotating the input shaft once, the rolling elements respectively held in the plurality of support grooves of the rolling element support portion are While rolling along the tooth of the bevel gear having an uneven shape along the moving center axis, it reciprocally swings in the axial direction, not in the radial direction of the input shaft. The plurality of rolling elements push the base plate while rolling by one tooth of the bevel gear, and the output shaft integrated with the base plate rotates 1 / n relative to the input shaft around the first rotation center axis. The reduction gear of the present application realizes the reduction ratio n.

  That is, the rolling element that reciprocally swings in the axial direction rather than the radial direction of the input shaft and the radial direction realizes a reduction gear having a reduction ratio n.

  Furthermore, in the speed reducer of the present application, the speed reduction mechanism includes a second speed reduction mechanism, and the second speed reduction mechanism is fixed to the case and faces the back surface of the swing plate and the input shaft. A second base plate disposed coaxially and rotatably holding the input shaft; and a rear surface of the swing plate or the second base plate so as to be convex in the axial direction of the first rotation center axis. A second bevel gear with n + 1 teeth provided on one of them and an n + 1 provided on the back surface of the swing plate or the other of the second base plates not provided with the second bevel gear. And a second rolling element support portion having a plurality of second support grooves of a maximum of n that do not have a common divisor other than 1, and inserted into the plurality of second support grooves, respectively. Between the second bevel gear and the second rolling element support. And so comprises a second rolling element groups of up to (n + 1) of a plurality of rolling elements having no common divisor other than 1 with respect to a plurality of the support groove and the following number equal n, the.

  (Operation) When the input shaft rotates relative to the case, the swinging plate rotatably supported by the tilt bearing in an inclined state has an intersection between the first rotation center axis and the second rotation center axis. It swings back and forth in the axial direction of the first rotation center axis about the center. When the swing plate reciprocally swings once in the axial direction of the first rotation center axis by rotating the input shaft once, the second rolling elements respectively held in the second support grooves are rotated in the first direction. While rolling along the teeth of the bevel gear having an uneven shape along the central axis, it reciprocates in the axial direction instead of in the radial direction of the input shaft. Since the second base plate is fixed to the case, each of the plurality of second rolling elements rolls by one tooth of the second bevel gear and moves the swing plate to the second rotation center via the support groove. Push around the axis to rotate the rocking plate 1 / (n + 1) relative to the case. As a result, the speed reducer of the present application is provided with a pair of speed reduction mechanisms in series on the back and front of the rocking plate, and transmits one rotation of the input shaft to the case by decelerating to 1 / na × 1 / nb rotation of the output shaft. As a result, a large reduction ratio n × (n + 1) is realized.

  That is, the input shaft and the rolling element that reciprocally swings in the axial direction instead of the radial direction of the radial direction realizes a reduction gear having a large reduction ratio n × (n + 1).

  Furthermore, in the speed reducer of the present application, the plurality of rolling elements are each formed in a tapered roller shape or a tapered roller shape.

  (Operation) Since the contact area of the rolling element with the teeth of the swing plate, the base plate and the bevel gear is increased, the surface pressure generated on the swing plate, the base plate, the teeth of the bevel gear and the rolling element is reduced, and the reduction gear Contributes to improved rigidity and life.

  Further, in the speed reducer of the present application, the inclined bearing is a rolling bearing.

  (Operation) The frictional force generated between the inclined bearing and the swing plate is reduced.

  Furthermore, in the speed reducer of the present application, the swing plate and the rolling element support are integrated.

  (Operation) The number of mechanical parts required for the reduction gear is reduced.

  According to the speed reducer of the present application, since a plurality of rolling elements swing in the axial direction of the input shaft and the output shaft, in addition to being formed small in the radial direction, a desired reduction ratio according to the number of teeth n is realized. In addition, it can be placed in a device that does not have a space in the radial direction of the speed reducer.

  According to the speed reducer of the present application, a desired large reduction ratio according to the number of teeth n and the number of teeth n + 1 is realized while the speed reducer is formed small in the radial direction.

  According to the speed reducer of the present application, the life of each rolling element, the teeth of the bevel tooth portion, the swing plate, and the base plate is improved by reducing wear.

  According to the speed reducer of the present application, the reduction in surface pressure improves the rigidity and life of the speed reducer.

  According to the speed reducer of the present application, the cost can be reduced by reducing the number of mechanism parts.

(A) Axial direction sectional view about the 1st example of a reduction gear. (B) A sectional view in the axial direction of the speed reducer when the input shaft is rotated 180 degrees. Explanatory drawing regarding arrangement | positioning of the rolling element group on a baseplate. (A) Arrangement explanatory drawing of each tooth of a rolling element group and a bevel gear in an initial position. (B) Arrangement explanatory drawing of each tooth of a rolling element group and bevel gears when an input shaft is rotated 180 degrees. (A) Axial direction sectional view about the 2nd example of a reduction gear. (B) A sectional view in the axial direction of the speed reducer when the input shaft is rotated 180 degrees. Explanatory drawing regarding arrangement | positioning of the 2nd rolling element group on a 2nd baseplate. (A) Arrangement explanatory drawing of each tooth of the 2nd rolling element group and bevel gears in an initial position. (B) Arrangement explanatory drawing of each tooth of the second rolling element group and the bevel gear when the input shaft is rotated 180 degrees.

  The configuration and operation of the speed reducer according to the first embodiment will be described with reference to FIGS. In FIG. 1 to FIG. 6, description will be made assuming that the front of the reduction gear is Fr, the rear is Re, the upper is Up, and the lower is Lw.

  As shown in FIGS. 1A and 1B, the speed reducer 40 according to the first embodiment includes a case 41, an input shaft 42, an output shaft 43, and a speed reduction mechanism 44.

  As shown in FIG. 1A, the case 41 includes a case main body 41a, an input shaft support portion 41b, a back cover 41c, and a plurality of male screws 41d. The case body 41a is integrally provided with a front plate 41f at the front end of the cylindrical portion 41e, and has a flange portion 41g on the outer periphery of the rear end. A circular hole 41h is provided in the center of the front plate 41f. The input shaft support portion 41b is a plate-like member having a circular hole 41i in the center, and is fixed inside the front plate 41f by a plurality of male screws 41d. The back cover 41c is formed in a disk shape and has a circular hole 41j in the center. The back cover 41c is fixed to the flange portion 41g with a plurality of male screws 41k in a state where an input shaft 42, an output shaft 43 and a speed reduction mechanism 44, which will be described later, are housed inside the case body 41a. The cylindrical portion 41e, the circular hole 41i, the circular hole 41h, and the circular hole 41j are arranged coaxially with a first rotation center axis L1 of the input shaft 42 described later.

  The input shaft 42 has a shape in which the first shaft portion 42a, the second shaft portion 42b, the inclined bearing 46, and the third shaft portion 42c are integrated in order from the front along the first rotation center axis L1. A through-hole 42d is provided at the center of the input shaft 42, and a drive source (such as an electromagnetic clutch mechanism or a motor) (not shown) is driven on the outer periphery of the cylindrical first shaft portion 42a or inside the through-hole 42d. The shaft is fixed from the front. The second shaft portion 42b is formed in a cylindrical shape having a larger outer diameter than the first shaft portion, and the third shaft portion 42c is set in a cylindrical shape having a smaller outer diameter than the first shaft portion. The input shaft 42 is rotatably held around the first rotation center axis L1 in a circular hole 41i of the input shaft support portion 41b of the case 41 by a rolling bearing 42e (such as a ball bearing or a roller bearing).

  As shown in FIG. 1A, the inclined bearing 46 includes a bearing body 46a and a support portion 46b. The support portion 46b has a cylindrical shape centered on a second rotation center axis L2 inclined at an angle θ with respect to the first rotation center axis L1, and a bearing body 46a that is a rolling bearing is fixed to the outer periphery.

  The speed reduction mechanism 44 includes a swing plate 45, a tilt bearing 46, a base plate 47, a bevel gear 48, a rolling element support portion 49, and a rolling element group 50.

  The base plate 47 shown in FIG. 1A is formed in a disc shape and has a circular hole 47a in the center. The output shaft 43 is fixed to the base plate 47. The output shaft 43 has a shape in which the cylindrical portion 43b is coaxially integrated with the rear surface of the disc portion 43a, and a circular hole 43c is provided at the center of each. The circular hole 43c and the circular hole 47a have inner diameters larger than the outer diameter of the third shaft portion 42c of the input shaft 42, respectively. The output shaft 43 is screwed to the rear surface 47 c of the base plate 47 by a plurality of male screws 43 d (partially omitted in FIG. 1) so as to be coaxial with the base plate 47. The base plate 47 and the output shaft 43 are both arranged coaxially with the first rotation center axis L1 of the input shaft 42 and are rotatably supported by the third shaft portion 42c of the input shaft 42 via the rolling bearing 47b. . Further, the disc portion 43a of the output shaft 43 is rotatably held inside the flange portion 41g of the case 41 via the rolling bearing 43e.

  2 shows a virtual view of only the base plate 47 and the rolling element group 50 as viewed from the front to the rear (see the direction of the arrow S1 in FIG. 1A). On the front surface of the base plate 47, a bevel gear 48 having the number of teeth n of 3 or more (in the first embodiment, the number of teeth is 6 as an example, but the number of teeth is not limited to 6) is provided. . Reference numerals 48a to 48f denote six teeth of the bevel gear 48 having a convex shape toward the front.

  The swing plate 45 shown in FIG. 1 (a) is formed in a disk shape with metal, resin, or the like, provided with a disk-shaped rolling element support portion 49 on the front surface (rear surface) 45a, and on the back surface (front surface) 45b. A disc-shaped bearing holding portion 45c is provided. The rocking plate 45 is provided with a circular hole 45d having the same inner diameter as the outer diameter of the bearing body 46a of the inclined bearing 46 at the center. The rocking plate 45 is fitted in the circular hole 45d with the bearing body 46a, and is supported by the inclined bearing 46 of the input shaft 42 so as to be rotatable around the second rotation central axis L2.

  Further, the rolling element support portion 49 and the bearing holding portion 45c each have a circular hole 49f and a circular hole 45e that are smaller in inner diameter than the circular hole 45d and are coaxial with the circular hole 45d. By squeezing the bearing body 46a by being integrated with the front and back of the swing plate 45 in a state flush with the outer periphery, the swing plate 45 is moved in the direction of the second rotation center axis L2 with respect to the bearing body 46a. Prevent it from coming off. Note that the rolling element support portion 49 and the bearing holding portion 45c may be formed as separate members as in this embodiment and integrated with the swing plate 45 by bonding or the like, or may be integrally formed with the swing plate 45. good. In the speed reducer 40 of the first embodiment, the support portion 46b is a sliding bearing without providing the bearing body 46a formed of a rolling bearing, and the swing plate 45 and the rolling element support portion 49 are directly rotated to the support portion 46b. It may be supported as possible.

  The rolling element support portion 49 includes a plurality of support grooves (49a to 49e) that form recesses and projections on the rear side along the second rotation center axis L2, and the rolling element does not come out radially outward of the rolling element support portion 49. It has a projection 49g for preventing it. The plurality of support grooves extend in the radial direction from the center of the circular hole 49f and are formed at equal intervals in the circumferential direction, and have a maximum n−1 that does not have a common divisor other than 1 for the number of teeth n of the bevel gear 48. Individually formed. In the first embodiment, as an example, five support grooves (49a to 49e) are provided in the rolling element support portion 49.

  In each of the five rolling element support grooves (49a to 49e), a plurality of rolling elements (50a to 50e) indicated by two-dot chain lines in FIG. 2 are inserted and held. The plurality of rolling elements (50 a to 50 e) are each formed in a tapered roller shape or a tapered roller shape as in the present embodiment, and constitute a rolling element group 50. In addition, the plurality of rolling elements (50a to 50e) are the same number or less as the plurality of support grooves (49a to 49e), and a maximum of n-1 having no common divisor other than 1 is provided for n. It is done. In the first embodiment, as shown in FIG. 2, as an example, the same number of five rolling elements (50a to 50e) as the support grooves (49a to 49e) are provided. The rolling elements (50a to 50e) are sandwiched between the bevel gear 48 and the rolling element support 49, as shown in FIGS. 1 (a) and 2, respectively, and have six teeth (48a to 48f). Roll.

  3A and 3B are virtual views for explaining the operation of the swing plate 45, the bevel gear 48, and the rolling element group 50. The bevel gear 48 in FIG. As viewed from above, it is assumed that the teeth (48a to 48f) and the rolling elements (50a to 50e) are linearly arranged on the basis of the position of the rolling element 50a. 1 (a) and see arrow view S2 of FIG. 2) FIG. The code | symbol 49h shows the curve which shows the positional relationship of the bottom part of the rolling element support part 49 with respect to a tooth | gear (48a-48f) and a rolling element (50a-50e). The bottom of the rolling element support 49 presses the rolling elements (50a to 50e) held in the support grooves (49a to 49e) at equal intervals against the teeth (48a to 48f).

  Next, the operation of the speed reducer 40 of the first embodiment will be described with reference to FIGS. When the input shaft 42 shown in FIG. 1A rotates, the second rotation center axis L2 of the inclined bearing 46 and the support portion 46b parallel to the axis L2 are at an angle θ with respect to the first rotation center axis L1. Is rotated around the first rotation center axis L1. The rocking plate 45 and the rolling element support portion 49 are attached to the support portion 46b via a bearing body 46a that is a rolling bearing so as to be rotatable relative to the support portion 46b. Therefore, the swing plate 45 and the rolling element support 49 do not rotate relative to the case 41 even when the support 46b rotates around the first rotation center axis L1, and the first rotation center axis and It swings back and forth along the first rotation center axis L1 about the intersection O1 of the second rotation center axis.

  Specifically, when the input shaft 42 shown in FIG. 1A rotates 180 degrees, the swing plate 45 and the rolling element support 49 disposed at the rearmost end of the swing at the initial position are centered on the intersection O1. It swings in the direction of D1, that is, from the rear to the front and moves to the foremost end of the swing in FIG. Further, when the input shaft 42 shown in FIG. 1B is rotated 180 degrees, the swing plate 45 and the rolling element support 49 swing around the intersection O1 in the direction D2, that is, from the foremost end to the end of the swing. Thus, the initial position of FIG. That is, the swing plate 45 and the rolling element support 49 of the first embodiment swing back and forth once per rotation of the input shaft.

  At that time, the rolling elements (50a to 50e) in FIG. 3 (a) are moved by the bottom 49h of the rolling element support part 49 that moves to the right while maintaining the sinusoidal curve shape in FIG. 3 (a). It is pressed by the teeth (48a to 48f). In FIG. 3A, the rolling element 50a is positioned at the rearmost end of the swing at the initial position, and the rolling element 50c is positioned at the foremost end of the swing at the initial position. When the input shaft 42 is rotated 180 degrees, that is, half-turned, the bottom 49h moves to the right by the half phase of the sinusoidal curve shape, and presses the rolling elements (50b, 50c) backward (Re direction). 50c moves from the position of the foremost end of the swing shown in FIG. 3 (a) to the end position shown in FIG. 3 (b). At that time, the rolling elements (50b, 50c) in FIG. 3 (a) press the teeth (48b, 48c) from the left side to the right direction (Re direction), respectively, as shown in FIG. 3 (b). The teeth (48a to 48f) are moved to the right by the half pitch of each tooth. As a result, when the input shaft 42 is rotated halfway, the output shaft 43 integrated with the bevel gear 48 rotates relative to the input shaft 42 by a half pitch of each tooth (48a to 48f).

  3B, when the input shaft 42 is further rotated 180 degrees, that is, half-turned, the bottom 49h further moves to the right by the half phase of the sinusoidal curve shape, and the rolling elements (50d, 50e, 50a). ) Is pushed backward (Re direction), and the rolling element 50a returns from the position of the foremost end of the swing shown in FIG. 3B to the end position (initial position) shown in FIG. At that time, the rolling elements (50d, 50e, 50a) respectively press the teeth (48d, 48e, 48f) from the left side to the right direction (Re direction), thereby further rotating the bevel gear 48 to each tooth (48a-48f). Is rotated relative to the input shaft 42 by a half pitch.

  When the input shaft 42 rotates once, the rolling elements (50a to 50e) reciprocate back and forth while rotating in the same direction as the input shaft 42 along the teeth (48a to 48f). As a result, the rolling elements (50a to 50e) rotate the output shaft 43 relative to the input shaft 42 by one pitch of each tooth (48a to 48f) in the rotation direction of the input shaft 42. That is, the speed reducer 40 of the first embodiment realizes a reduction ratio n by decelerating and transmitting one rotation of the input shaft 42 to 1 / n rotation of the output shaft, where n is the number of teeth of the bevel gear. To do. Since the bevel gear 48 of the present embodiment has 6 teeth, the speed reducer 40 achieves a reduction ratio of 6.

  In the reduction gear 40 of the first embodiment, the bevel gear 48 is formed in the base plate 47 and the support grooves (49a to 49e) are provided in the swing plate 45. Conversely, the bevel gear 48 is moved to the swing plate 45. A rolling element support 49 having support grooves (49a to 49e) facing the bevel gear may be provided on the base plate.

  Next, the configuration and operation of the speed reducer according to the second embodiment will be described with reference to FIGS. In the speed reducer 56 of the second embodiment shown in FIGS. 4A and 4B, the speed reduction mechanism 44 is provided with the second speed reduction mechanism 52, and the input shaft support portion 41 b of the case 41 is used as the second base plate 57. In addition to changing the bearing holding portion 45c of the swing plate 45 to the second rolling element support portion 59, it has the same configuration as the speed reducer 40 of the first embodiment.

  Specifically, the speed reducer 56 of the second embodiment includes the swing plate 45, the inclined bearing 46, the base plate 47, the bevel gear 48, the rolling element support portion 49, and the rolling element group 50 of the first embodiment. In addition to the first speed reduction mechanism 51 configured on the front surface 45a side of 45, a second speed reduction mechanism 52 shown in FIG. The speed reduction mechanism 44 'in which the speed reduction mechanisms (51, 52) are arranged in series is configured.

  The second speed reduction mechanism 52 shown in FIG. 4A includes a swing plate 45, an inclined bearing 46, a second base plate 57, a second bevel gear 58, a second rolling element support portion 59, and a second rolling element. It has a moving body group 60.

  As shown in FIG. 4A, not the input shaft support portion 41b of the first embodiment but the second base plate 57 is fixed inside the front plate 41f of the case 41 of the second embodiment. The second base plate 57 is formed in a disc shape, has a circular hole 57a in the center, and is fixed to the front plate 41f by a plurality of male screws 41d. At that time, the circular hole 57 a is arranged coaxially with the circular hole 41 h of the case 41. The input shaft 42 is rotatably held around the first rotation center axis L1 in a circular hole 57a of the second base plate 57 fixed to the case 41 by a rolling bearing 42e (such as a ball bearing or a roller bearing). The

  5 shows a virtual view of only the second base plate 57 and the second rolling element group 60 as viewed from the rear to the front (see the direction of arrow S3 in FIG. 4A). On the rear surface of the second base plate 57, a second bevel gear 58 having the number of teeth n + 1 (n is the number of teeth of the bevel gear 48 of the first reduction mechanism 51) having three or more teeth is provided. In the second embodiment, the number of teeth of the second bevel gear 58 is set to 7 based on the number of teeth of the bevel gear 48 set to 6 as an example, but the number of teeth is not limited to 7. Reference numerals 58a to 58g denote seven teeth of the second bevel gear 58 having a convex shape toward the rear.

  As shown in FIG. 4 (a), the back surface (front surface) 45b of the rocking plate 45 of the second embodiment is not the bearing holding portion 45c of the first embodiment but the disk shape shown in FIG. 4 (a). A second rolling element support 59 is provided. The second rolling element support portion 59 is formed of metal, resin, or the like, similar to the swing plate 45. The second rolling element support portion 59 may be formed as a separate member as in this embodiment and integrated with the swing plate 45 by adhesion or the like, or may be integrally formed with the swing plate 45. A circular hole 59g having an inner diameter smaller than the circular hole 45d of the swing plate 45 and coaxial with the circular hole 45d is provided at the center of the second rolling element support portion 59. The rolling element support 49 and the second rolling element support 59 are integrated with the front and back of the swing plate 45 with the outer periphery thereof being flush with the outer periphery of the swing plate 45, thereby sandwiching the bearing body 46 a. By doing so, the rocking plate 45 is prevented from coming off in the direction of the second rotation center axis L2 with respect to the bearing body 46a.

  The second rolling element support portion 59 includes a plurality of support grooves (59a to 59f) that form an unevenness on the rear side along the second rotation center axis L2 of the inclined bearing 46 inclined with respect to the first rotation center axis L1. ) And a protrusion 59h for preventing the rolling element from coming out radially outward of the rolling element support 49. The plurality of support grooves extend radially from the center of the circular hole 59g, are formed at equal intervals in the circumferential direction, and have no common divisor other than 1 with respect to the number of teeth n + 1 of the second bevel gear 58. At most n pieces are formed. In the first embodiment, as an example, six support grooves (59a to 59f) are provided in the second rolling element support portion 59.

  In the six rolling element support grooves (59a to 59f), a plurality of rolling elements (60a to 60f) indicated by two-dot chain lines in FIG. 5 are inserted and held. The plurality of rolling elements (60a to 60f) are each formed in a tapered roller shape or a tapered roller shape as in the present embodiment, and constitute the second rolling element group 60. In addition, the plurality of rolling elements (60a to 60f) are provided in the maximum number n that is equal to or less than the plurality of support grooves (59a to 59f) and does not have a common divisor other than 1 for n. In the second embodiment, as shown in FIG. 4, as an example, the same number of six rolling elements (60a to 60f) as the support grooves (59a to 59f) are provided. The rolling elements (60a to 60f) are sandwiched between the second bevel gear 58 and the second rolling element support portion 59, as shown in FIGS. 4A and 5, respectively, and have seven teeth (58a). Rolling to ~ 58 g).

  6A and 6B are virtual views for explaining the operation of the swing plate 45, the second bevel gear 58, and the second rolling element group 60. FIG. The two bevel gears 58 are cut at the position of the cutting line II-II, and the teeth (58a to 58g) and the rolling elements (60a to 60f) are linearly arranged on the basis of the position of the rolling element 60a. FIG. 6 is a virtual diagram viewed from above (see FIG. 4A and the arrow S4 in FIG. 5). The code | symbol 59i shows the curve which shows the positional relationship of the bottom part of the 2nd rolling element support part 59 with respect to a tooth | gear (58a-58g) and a rolling element (60a-60f). The bottom of the second rolling element support 59 presses the rolling elements (60a to 60f) held in the support grooves (59a to 59f) at equal intervals against the teeth (58a to 58g).

  Next, the operation of the speed reducer 56 of the fourth embodiment will be described with reference to FIGS. When the input shaft 42 shown in FIG. 4A rotates, the second rotation center axis L2 of the inclined bearing 46 and the support portion 46b parallel to the axis L2 are at an angle θ with respect to the first rotation center axis L1. Is rotated around the first rotation center axis L1. The swing plate 45, the rolling element support 49, and the second rolling element support 59 are attached to the support 46b via a bearing body 46a that is a rolling bearing so as to be relatively rotatable. The swing plate 45, the rolling element support part 49, and the second rolling element support part 59 are moved to the first time when the support part 46b rotates halfway (180 ° rotation) around the first rotation center axis L1 together with the input shaft 42. When the support portion 46b is rotated halfway by swinging from the rear end position, which is the initial position, to the front end position in FIG. 4 (b) around the intersection O1 of the moving center axis and the second rotation center axis, FIG. It swings to the rear end position which is the initial position of (a). That is, the rolling element support 49 and the second rolling element support 59 swing back and forth once along the first rotation center axis L1 when the input shaft 42 rotates once.

  When the input shaft 42 shown in FIG. 4A is rotated halfway (180 °), the second rolling element support portion 59 is moved from the rear end position, which is the initial position, to the front end position shown in FIG. 4B. When rocking, the rolling elements (60b to 60d) in the second rolling element group 60 receive a force directed forward (Fr direction) from the bottom 59i of the second rolling element support part 59. Since the second bevel gear 58 is fixed to the case 41, the rolling elements (60 b to 60 d) in FIG. 4 (a) are inserted into the FIG. 4 (a) via the second support grooves (59 b to 59 d). The second rolling element support portion 59 is pushed leftward (Le direction) by a half pitch of each tooth (58a to 58g). As a result, when the input shaft 42 is rotated halfway, the integrated second base plate 57, swing plate 45 and rolling element support 49 are half pitch of each tooth (58a to 58g) with respect to the input shaft 42. Rotate relative to the rotation direction of the input shaft 42 in the opposite direction.

  Further, when the input shaft 42 shown in FIG. 4B further rotates halfway (180 °), the second rolling element support portion 59 moves from the rear end position to the front end position (initial stage) in FIG. 4A. When returning to the position), the rolling elements (60a, 60e, 60f) in the second rolling element group 60 receive a force toward the front (Fr direction) from the bottom 59i of the second rolling element support part 59. The rolling elements (60a, 60e, 60f) in FIG. 4 (b) connect the second rolling element support part 59 in FIG. 4 (b) to the teeth (second teeth) via the second support grooves (60a, 60e, 60f). 58a-58g) is further pushed leftward (Le direction) by a half pitch. As a result, the second rolling element support 59, the swing plate 45, and the rolling element support 49 are in the rotational direction of the input shaft 42 by the half pitch of each tooth (58a to 58g) with respect to the input shaft 42. On the other hand, it rotates relative to the opposite direction.

  That is, when the input shaft 42 rotates once, the rolling elements (60a to 60f) reciprocate back and forth one by one, whereby the second rolling element support 59, the swing plate 45, and the rolling element support 49 are connected to the input shaft 42. On the other hand, the second bevel gear is relatively rotated in the direction opposite to the rotation direction of the input shaft 42 by one pitch of each tooth (58a to 58g) of the second bevel gear. That is, the speed reducer 56 of the second embodiment sets the number of teeth of the bevel gear 48 of the first speed reduction mechanism 51 to n and the number of teeth of the second bevel gear 58 of the second speed reduction mechanism 52 to n + 1, Assuming that the moving plate 45 and the rolling element support 49 are output shafts, one rotation of the input shaft 42 is decelerated and transmitted as 1 / (n + 1) rotation of the output shaft (swing plate 45 and rolling element support 49). The reduction gear has a reduction ratio n + 1. Since the second bevel gear 58 of the second embodiment has seven teeth, the second reduction mechanism 52 realizes a reduction mechanism with a reduction ratio of 7.

  As in the first embodiment, the first reduction mechanism 51 includes a rocking plate 45, an inclined bearing 46, a base plate 47, a bevel gear 48 having n teeth, a rolling element support portion 49, and a rolling element group 50. 6 speed reduction mechanism is realized. Accordingly, the rolling elements (50 a to 50 e) of the first speed reduction mechanism 51 have a force in the front-rear direction from the swinging plate 45 that has made one rotation of the input shaft and swung back and forth without rotating relative to the case 41. In response, the output shaft 43 is rotated 1 / n with respect to the input shaft 42 in the rotational direction of the input shaft. However, in the second embodiment, the second speed reduction mechanism 52 moves the swing plate 45 and the rolling element support 49 to the case 41 and the input shaft 42 in the direction opposite to the rotation direction of the input shaft 1 / (n + 1). In order to rotate, the rolling distance of the rolling element (50a-50e) with respect to the tooth | gear (48a-48f) of the 1st deceleration mechanism 51 is reduced. As a result, the speed reducer 56 of the second embodiment has a configuration in which the first speed reduction mechanism 51 having the speed reduction ratio n and the second speed reduction mechanism 52 having the speed reduction ratio n + 1 are arranged in series. , N (n + 1), and a reduction gear having a large reduction ratio proportional to the number of teeth n of the bevel gear 48 and the number of teeth n + 1 of the second bevel gear 58 is obtained.

  In the speed reducer 56 of the second embodiment, the second bevel gear 58 is formed on the second base plate 57 and the second support grooves (59a to 59f) are provided on the swing plate 45. The second bevel gear 58 is provided on the surface of the swing plate 45, and the second rolling element support portion 59 having the second support grooves (59a to 59f) facing the second bevel gear 58 is provided in the second It may be provided on the base plate 57. Further, in the speed reducer 56 of the second embodiment, the support portion 46b is a sliding bearing without providing the bearing body 46a composed of a rolling bearing, and the swing plate 45, the rolling element support portion 49, and the second rolling element support portion. 59 may be directly supported by the support portion 46b so as to be rotatable.

  According to the speed reducer 40 of the first embodiment, the swing plate 45 and the plurality of rolling elements (50a to 50e) are in the axial direction of the input shaft 42 and the output shaft 43, that is, the direction along the first rotation center axis L1. Since the size of the speed reducer 40 including the case 41 can be reduced in the radial direction while realizing a desired reduction ratio based on the number of teeth n, there is a margin in the radial direction of the speed reducer. The speed reducer 40 can be installed in a device that does not have an arrangement space inside.

  Moreover, according to the speed reducer 56 of 2nd Example, in addition to the 1st speed reduction mechanism 51, it has the 2nd rolling element (60a-60f) rock | fluctuated in the direction along the 1st rotation center axis L1. By providing the speed reduction mechanism 52 in series on the front and back of the rocking plate 45, the number of teeth n of the bevel gear 48 and the number of teeth n + 1 of the second bevel gear 58 are not increased in the radial direction. A reduction gear with a large reduction ratio in proportion to is realized.

40 Reduction gear 41 Case 42 Input shaft 43 Output shaft 44, 44 'Deceleration mechanism 45 Oscillating plate 45a Oscillating plate surface 45b Oscillating plate rear surface 46 Inclined bearing 47 Base plate 48 Bevel gear 49 Rolling body support portions 49a to 49e Groove 50 Rolling element groups 50a to 50e Rolling element 51 First reduction mechanism 52 Second reduction mechanism 56 Reduction gear 57 Second base plate 58 Second bevel gear 59 Second rolling element support portions 59a to 59f Second Support groove 60 2nd rolling element group 60a-60f Rolling element L1 1st rotation center axis L2 2nd rotation center axis

[0010]
It swings in the direction of D2, that is, from the foremost end to the end of the swing, and returns to the initial position in FIG. That is, the swing plate 45 and the rolling element support 49 of the first embodiment swing back and forth once per rotation of the input shaft.
[0042]
At that time, the rolling elements (50a to 50e) in FIG. 3 (a) are moved by the bottom 49h of the rolling element support part 49 that moves to the right while maintaining the sinusoidal curve shape in FIG. 3 (a). It is pressed by the teeth (48a to 48f). In FIG. 3A, the rolling element 50a is positioned at the rearmost end of the swing at the initial position, and the rolling element 50c is positioned at the foremost end of the swing at the initial position. When the input shaft 42 is rotated 180 degrees, that is, half-turned, the bottom 49h moves to the right by the half phase of the sinusoidal curve shape, and presses the rolling elements (50b, 50c) backward (Re direction). 50c moves from the position of the foremost end of the swing shown in FIG. 3 (a) to the end position shown in FIG. 3 (b). At that time, the rolling elements (50b, 50c) in FIG. 3 (a) press the teeth (48b, 48c) from the left to the right (Ri direction), respectively, as shown in FIG. 3 (b). The teeth (48a to 48f) are moved to the right by the half pitch of each tooth. As a result, when the input shaft 42 is rotated halfway, the output shaft 43 integrated with the bevel gear 48 rotates relative to the input shaft 42 by a half pitch of each tooth (48a to 48f).
[0043]
3B, when the input shaft 42 is further rotated 180 degrees, that is, half-turned, the bottom 49h further moves to the right by the half phase of the sinusoidal curve shape, and the rolling elements (50d, 50e, 50a). ) Is pushed backward (Re direction), and the rolling element 50a returns from the position of the foremost end of the swing shown in FIG. 3B to the end position (initial position) shown in FIG. At that time, the rolling elements (50d, 50e, 50a) respectively press the teeth (48d, 48e, 48f) from the left side to the right direction (Ri direction), thereby further rotating the bevel gear 48 to each tooth (48a-48f). Is rotated relative to the input shaft 42 by a half pitch.
[0044]
When the input shaft 42 rotates once, the rolling elements (50a to 50e) reciprocate back and forth while rotating in the same direction as the input shaft 42 along the teeth (48a to 48f). As a result, the rolling elements (50 a to 50 e) have the output shaft 43 paired with the input shaft 42.

Claims (5)

Case and
An input shaft rotatably supported by the case;
An output shaft that is rotatably supported by the case and that is coaxially and relatively rotatable with the input shaft;
A deceleration mechanism that decelerates the rotation of the input shaft and transmits it to the output shaft;
In a reducer having
The deceleration mechanism is
A swing plate;
An inclined bearing provided in a circumferential direction on the outer periphery of the input shaft, and rotatably supporting the swing plate about a second rotation center axis inclined with respect to the first rotation center axis of the input shaft;
A base plate disposed coaxially with the input shaft in a state facing the surface of the swing plate, rotatably supported by the input shaft, and integrated with the output shaft;
A bevel gear with n teeth having three or more teeth provided on one of the surface of the swing plate or the base plate so as to be convex in the axial direction of the first rotation center axis;
A plurality of support grooves of a maximum of n−1 which do not have a common divisor other than 1 with respect to n, which is provided on the surface of the swing plate or the other of the base plates where the bevel gear is not provided. A rolling element support,
The number is equal to or less than the number of the plurality of support grooves inserted into the plurality of support grooves and sandwiched between the bevel gear and the rolling element support, and has a common divisor other than 1 for n. A rolling element group consisting of a plurality of rolling elements up to n−1,
A speed reducer comprising: The speed reduction mechanism has a second speed reduction mechanism,
The second reduction mechanism is
A second base plate fixed to the case and disposed coaxially with the input shaft in a state of facing the back surface of the swing plate, and holding the input shaft rotatably;
A second bevel gear having n + 1 teeth provided on one of the back surface of the swing plate or the second base plate so as to be convex in the axial direction of the first rotation center axis;
A maximum of n plurality having no common divisor other than 1 with respect to n + 1, provided on the back surface of the swing plate or on the other side of the second base plate where the second bevel gear is not provided. A second rolling element support portion having a second support groove;
The number is equal to or less than the number of the plurality of support grooves inserted into the plurality of second support grooves and sandwiched between the second bevel gear and the second rolling element support portion, and n A second rolling element group consisting of a plurality of rolling elements of at most n + 1 having no common divisor other than 1,
The speed reducer according to claim 1, comprising:   The reduction gear according to claim 1 or 2, wherein each of the plurality of rolling elements has a tapered roller shape or a tapered roller shape.   The speed reducer according to claim 1 or 2, wherein the inclined bearing is a rolling bearing. The speed reducer according to claim 1 or 2, wherein the swing plate and the rolling element support portion are integrated.

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