JP2018071721A - Composite transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize a transmission by simplifying precompression structure, to transmit rotary driving force certainly, and to obtain large gear ratio.SOLUTION: A first transfer mechanism 4 of a composite transmission 1 includes an inner ring 9, an outer ring 10, multiple rolling elements 11 placed to roll between the inner ring 9 and the outer ring 10, and an intermediate shaft 13 engaging with the rolling elements 11 and transmitting rotation driving force to a second transfer mechanism 5. The second transfer mechanism 5 of the composite transmission 1 includes a sun member 16 provided to the intermediate shaft 13, a planet member 17 engaging with the sun member 16, and a cyclic member 18 engaging with the planet member 17. A precompression system 14 of the composite transmission 1 is consisted by setting that a diameter D1 of the rolling element 11 is bigger than a distance L1 between a contact point CP1 that the rolling element 11 contacts with an orbital plane 9a of the inner ring 9 and a contact point CP2 that the rolling element 11 contacts with an orbital plane 10a of the outer ring 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a compound transmission including a plurality of power transmission mechanisms.

  A traction drive is used as a transmission for decelerating or increasing the speed of rotation driven by a drive source such as a motor. A traction drive is a kind of friction transmission device, and transmits power through an oil film formed between two surfaces having a smooth surface. As an example, Patent Document 1 discloses a transmission including a casing, an input shaft that is rotatably supported by the casing, and an output shaft that is rotatably supported by the casing on the same axis as the input shaft. (Microtraction drive) is disclosed.

  In this transmission, the input shaft includes an inner ring, and an angle groove is formed in the inner ring as an inner ring raceway surface. An outer ring is fixed to the housing, and an angle groove is formed on the outer ring as an outer ring raceway surface. A plurality of rolling elements (rotating bodies) are arranged between the inner ring raceway surface and the outer ring raceway surface. A cage for holding each rolling element is provided integrally with the output shaft.

  In this transmission, a rotational driving force is transmitted from the input shaft to the inner ring, and the rolling element revolves around the axis of the input shaft while rotating according to the rotational driving force of the inner ring. The rotational force due to the revolution of the rolling elements is transmitted to the output shaft through the cage.

  In the traction drive, it is necessary to apply a preload to the rolling elements so that the rolling elements roll according to the rotation of the inner ring. For this reason, a press ring that can press the outer ring is disposed between the housing and the outer ring. The pressing ring has a plurality of inclined surfaces on the outer ring side. A pressing rotating body (pressing ball) is fitted between the pressing ring and the outer ring.

  The transmission can adjust the preload applied to the rolling element by the outer ring raceway surface and the inner ring raceway surface by rotating the pressing ring and moving the outer ring to the input shaft side via the pressing rotator. (See paragraphs 0018 to 0022 of FIG. 1 and FIG. 1).

  Patent Document 2 discloses a transmission (microtraction drive) that can apply a preload to the inner ring raceway surface, the outer ring raceway surface and the rolling elements by using a spring. In this transmission, an inner ring is provided on the tip side of the input shaft support bearing (angle bearing), the inner ring and the inner ring of the input shaft support bearing are connected by a spring (second spring), and arranged coaxially with the inner ring. The outer ring and a part of the housing are connected by a spring (first spring). The inner ring and the outer ring are formed with an inner ring raceway surface and an outer ring raceway surface made of angle grooves.

  In this transmission, the normal force (preload) is applied to the contact surface between the rolling element (ball) and each raceway surface by the biasing force of these springs (see paragraphs 0054 to 0066 and FIG. 4 of the same document). ).

Japanese Patent No. 3617645 Japanese Patent No. 3659925

  As described above, since the conventional transmission uses a separate preload adjusting mechanism such as a press ring or a spring, the structure of the transmission is complicated, resulting in an increase in size and cost. Further, when preload is applied by using the raceway surfaces of the inner ring and the outer ring as angle grooves, the rolling elements are likely to slip, and the rotational driving force may not be reliably transmitted.

  The present invention has been made in view of the above circumstances, and it is a technology that simplifies the preload structure to reduce the size of the transmission, reliably transmits the rotational driving force, and obtains a large gear ratio. As an objective.

  The present invention is to solve the above-described problem, and includes an input shaft, an output shaft that outputs a rotational driving force input to the input shaft, and the rotational driving force of the input shaft at a predetermined speed ratio. A first transmission mechanism that converts the rotational driving force transmitted from the first transmission mechanism at a predetermined gear ratio, and transmits the pre-load to the first transmission mechanism. A preload mechanism for applying, wherein the first transmission mechanism is provided on the input shaft and has an inner ring having a raceway surface, an outer ring having a raceway surface, and the raceway surface of the inner ring. A plurality of rolling elements arranged to roll with the raceway surface of the outer ring, and the rotational driving force is transmitted to the second transmission mechanism by engaging with the rolling elements and rotating. An intermediate shaft, and the second transmission mechanism is provided on the intermediate shaft. A solar member that engages with the solar member, an annular member that engages with the planetary member, and a rotation that engages and rotates with the planetary member to transmit the rotational driving force to the output shaft. A carrier, and the preload mechanism has a diameter of the rolling element, a contact point where the rolling element contacts the raceway surface of the inner ring, and a contact point where the rolling element contacts the raceway surface of the outer ring. It is characterized by being made larger than the distance between.

  According to such a configuration, by setting the diameter of the rolling element to be larger than the distance between the contact points, when this rolling element is disposed between the inner ring and the outer ring, the inner ring, the outer ring, and the rolling element have an axis line. Stress in a direction perpendicular to the direction is generated, and this can be suitably applied as a preload. As a result, the rotational driving force input to the input shaft can be reliably transmitted to the output shaft via the first transmission mechanism and the second transmission mechanism. Thus, in the present invention, since the preload can be applied without using a separate preload mechanism using only the bearing structure including the inner ring, the outer ring, and the rolling elements, the composite transmission can be made smaller than before. it can. In the present invention, a larger transmission ratio is obtained by using the second transmission mechanism including the planetary mechanism in addition to the first transmission mechanism.

  In this case, the intermediate shaft has a power transmission unit that transmits the rotational driving force of the input shaft to the intermediate shaft by engaging with the rolling element and rotating, and the power transmission unit includes A cage that holds the rolling elements is desirable. According to this, while a rolling element is suitably hold | maintained with a predetermined space | interval with a holder | retainer, when a holder | retainer rotates according to rolling of a rolling element, a rotational driving force can be reliably transmitted to an intermediate shaft.

  The compound transmission according to the present invention is provided between the output shaft and the second transmission mechanism, converts the rotational driving force transmitted from the second transmission mechanism at a predetermined gear ratio, and outputs the output. A configuration further including a third transmission mechanism that transmits to the shaft may be employed. As described above, by adding the third transmission mechanism, an even greater gear ratio can be realized.

  In this case, the third transmission mechanism is fixed to the carrier of the second transmission mechanism and has an inner ring having a raceway surface, an outer ring having a raceway surface, the raceway surface of the inner ring, and the raceway of the outer ring. A plurality of rolling elements disposed so as to roll with respect to the surface, and a power transmission unit that transmits the rotational driving force to the output shaft by engaging and rotating with the rolling elements. Preferably, the power transmission unit is the retainer that retains the rolling elements and is configured integrally with the output shaft. According to this, the rotation driving force can be reliably transmitted from the third transmission mechanism to the output shaft by rotating the cage according to the rolling of the rolling element.

  In the compound transmission according to the present invention, the compound transmission is provided between the first transmission mechanism and the second transmission mechanism, and the rotational driving force of the first transmission mechanism is converted at a predetermined speed ratio to convert the rotational transmission force. You may employ | adopt the structure further provided with the said 3rd transmission mechanism which transmits to a 2nd transmission mechanism. As described above, by adding the third transmission mechanism, an even greater gear ratio can be realized.

  In this case, the third transmission mechanism is fixed to the intermediate shaft of the first transmission mechanism and has an inner ring having a raceway surface, an outer ring having a raceway surface, the raceway surface of the inner ring, and the outer ring. A plurality of rolling elements arranged to roll with the raceway surface, and the rotational driving force of the first transmission mechanism to the second transmission mechanism by engaging and rotating with the rolling elements. And an intermediate shaft for transmission. According to this, the 3rd transmission mechanism can transmit the rotational driving force by rolling of a rolling element to a 2nd transmission mechanism reliably by the intermediate shaft.

  In addition, the compound transmission according to the present invention includes a preload mechanism that applies preload to the third transmission mechanism, and the preload mechanism determines the diameter of the rolling element in the third transmission mechanism in the third transmission mechanism. It may be configured by setting the distance between the contact point at which the rolling element contacts the raceway surface of the inner ring and the contact point at which the rolling element contacts the raceway surface of the outer ring. According to this, by setting the diameter of the rolling element to be larger than the distance between the contact points described above, when this rolling element is disposed between the inner ring and the outer ring, the inner ring, the outer ring and the rolling element have an axis line. Stress in a direction perpendicular to the direction is generated, and this can be suitably applied as a preload.

  According to the present invention, it is possible to simplify the preload structure to reduce the size of the transmission, to reliably transmit the rotational driving force, and to obtain a large gear ratio.

It is sectional drawing of the compound transmission which concerns on 1st Embodiment. It is a perspective view containing the principal part cross section of a compound transmission. It is a perspective view which shows a 1st transmission mechanism. It is a disassembled perspective view which shows a 1st transmission mechanism. It is a figure which shows an inner ring | wheel, an outer ring | wheel, and a rolling element in a 1st transmission mechanism. It is a perspective view which shows a 2nd transmission mechanism. It is a disassembled perspective view which shows a 2nd transmission mechanism. It is a perspective view which shows a 3rd transmission mechanism. It is a disassembled perspective view which shows a 3rd transmission mechanism. It is a figure which shows an inner ring | wheel, an outer ring | wheel, and a rolling element in a 3rd transmission mechanism. It is sectional drawing of the compound transmission which concerns on 2nd Embodiment. It is sectional drawing of the compound transmission which concerns on 3rd Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  1 to 10 show a first embodiment of a compound transmission according to the present invention. As shown in FIG. 1, the compound transmission 1 converts an input shaft 2, an output shaft 3 that outputs a rotational driving force input to the input shaft 2, and a rotational driving force of the input shaft 2 at a predetermined gear ratio. The first transmission mechanism 4, the second transmission mechanism 5 that converts the rotational driving force transmitted from the first transmission mechanism 4 at a predetermined gear ratio, and the rotational driving force transmitted from the second transmission mechanism 5 to the predetermined transmission ratio. A third transmission mechanism 6 that converts the transmission ratio and a casing 7 that houses the transmission mechanisms 4 to 6 are mainly provided.

  As shown in FIGS. 1 and 2, the input shaft 2 is supported by the casing 7 such that one end is accommodated in the casing 7 and the other end is exposed from the casing 7. The input shaft 2 has one end portion as a large diameter portion 2a and the other end portion as a small diameter portion 2b. The large diameter portion 2 a of the input shaft 2 is rotatably supported by the first transmission mechanism 4. At one end of the input shaft 2, a locking portion 2 c is formed that has a larger diameter than the large-diameter portion 2 a and that locks the input shaft 2 so that it does not come off the casing 7. A projection 2d is formed at the center (axial center) of the end surface in the axial direction of the large diameter portion 2a. The protrusion 2d is formed in a hemispherical shape having a spherical surface. The small diameter portion 2b of the input shaft 2 is connected to a drive source (not shown) such as a motor.

  As shown in FIGS. 1 and 2, the output shaft 3 is supported by the casing 7 such that one end is accommodated in the casing 7 and the other end is exposed from the casing 7. The output shaft 3 has a large diameter portion 3a at one end and a small diameter portion 3b at the other end. The output shaft 3 is arranged coaxially with the input shaft 2 so that the large diameter portion 3 a faces the large diameter portion 2 a of the input shaft 2. The large diameter portion 3 a of the output shaft 3 is supported by a bearing 8 held in the casing 7. A concave portion 3c with which a part of the second transmission mechanism 5 is engaged is formed at the center of the end surface in the axial direction of the large diameter portion 3a.

  The 1st transmission mechanism 4 comprises a traction drive by the bearing structure (for example, deep groove ball bearing) which supports the input shaft 2 rotatably. Specifically, as shown in FIGS. 1 to 4, the first transmission mechanism 4 includes an inner ring 9 that is fixed to the input shaft 2, an outer ring 10 that is coaxially disposed outside the inner ring 9, and an inner ring. 9 and a plurality of rolling elements 11 provided so as to roll between the outer ring 10 and an intermediate shaft 13 including a retainer 12 that holds the rolling elements 11.

  The inner ring 9 is configured in an annular shape and is fixed by being fitted into the large-diameter portion 2 a of the input shaft 2. The locking portion 2c of the input shaft 2 is in contact with the inner ring 9, and the locking portion 2c locks the input shaft 2 so that it does not come off. The inner ring 9 has a concave raceway surface 9a on which the rolling element 11 can roll. The track surface 9a is formed in an arc shape in a cross-sectional view. Here, when the rolling element 11 is disposed between the inner ring 9 and the outer ring 10, a location where the rolling element 11 can contact on the raceway surface 9a of the inner ring 9 is defined as a contact point CP1 (inner ring side contact point) (FIG. 5). This contact point CP1 is at the deepest position of the raceway surface 9a configured in a concave shape, and is located on the center line X with respect to the raceway surface 9a.

  The outer ring 10 is an annular body having an inner diameter larger than the outer diameter of the inner ring 9. The outer ring 10 is fixed so as not to rotate inside the casing 7. The outer ring 10 has a concave raceway surface 10a on which the rolling element 11 can roll. The track surface 10a is formed in an arc shape in a cross-sectional view. Here, when the rolling element 11 is disposed between the inner ring 9 and the outer ring 10, a location where the rolling element 11 can contact on the raceway surface 10a is defined as a contact point CP2 (outer ring side contact point) (see FIG. 5). . The contact point CP2 is at the deepest position of the raceway surface 10a configured in a concave shape, and is located on the center line X with respect to the raceway surface 10a.

  In the present embodiment, the rolling element 11 is constituted by a ball (sphere), but is not limited thereto, and may be constituted by a cylindrical roller. As shown in FIG. 5, the diameter D1 of the rolling element 11 is the radial direction between the contact point CP1 on the raceway surface 9a of the inner ring 9 and the contact point CP2 on the raceway surface 10a of the outer ring 10 when the rolling element 11 is not incorporated. It is set to be larger than the distance L1 at. This distance L1 is the minimum radius (the radius of the track surface 9a at the position of the contact point CP1) of the inner ring 9 and the maximum radius of the track surface 10a of the outer ring 10 (the radius of the track surface 10a at the position of the contact point CP2). ). By setting the distance between the contact points CP1 and CP2 in this way, when the rolling element 11 is assembled between the inner ring 9 and the outer ring 10, the bearing internal clearance (radial clearance) in the bearing structure becomes negative, Stress in a direction orthogonal to the axial direction can be generated on the inner ring 9, the outer ring 10 and the rolling element 11, and this can be applied as a preload. Thus, the preload mechanism 14 for applying preload to the first transmission mechanism 4 is configured by the dimensional relationship among the inner ring 9, the outer ring 10, and the rolling elements 11.

  The intermediate shaft 13 is located between the input shaft 2 and the output shaft 3 and is arranged coaxially therewith. The intermediate shaft 13 has a large diameter portion 13a at one end and a small diameter portion 13b at the other end. The large diameter portion 13 a functions as a power transmission portion that engages with the rolling elements 11 of the first transmission mechanism 4 and transmits the rotational driving force to the second transmission mechanism 5. The large diameter portion 13a integrally includes a cage 12 that holds the rolling element 11. The retainer 12 is formed with a notch 12 a for retaining the rolling element 11. Moreover, the large diameter part 13a is supported by the bearing 15 hold | maintained inside the casing 7, as shown in FIG. 1, FIG.

  The large-diameter portion 13a has a concave portion 13c that engages with the protruding portion 2d of the input shaft 2 on its axial end surface. The recessed part 13c is formed in the center part (axial center part) in the end surface of the large diameter part 13a. As shown in FIG. 1, the protrusion 2d of the input shaft 2 is in contact (point contact) with the bottom surface of the recess 13c.

  The small diameter portion 13 b of the intermediate shaft 13 supports a part of the second transmission mechanism 5. A protrusion 13e is formed at the center (axial center) of the end surface in the axial direction of the small diameter portion 13b. The protrusion 13e is formed in a hemispherical shape having a spherical surface.

  The second transmission mechanism 5 includes a solar member 16 provided in the middle portion of the intermediate shaft 13 in the first transmission mechanism 4, a planetary member 17 that engages with the solar member 16, and an annular member 18 that engages with the planetary member 17. And a carrier 19 connected to the planetary member 17.

  In the present embodiment, the sun member 16 is a sun gear, and the planetary member 17 is three planetary gears that mesh with the sun gear 16. The annular member 18 is an internal gear that meshes with the planetary gear 17. That is, the 2nd transmission mechanism 5 in this embodiment is comprised by the planetary gear mechanism. Hereinafter, the common symbol 16 is used for the sun member and the sun gear, and the common symbol 17 is used for the planetary member and the planetary gear. Moreover, the common code | symbol 18 is used for an annular member and an internal gear.

  The second transmission mechanism 5 is not limited to the planetary gear mechanism, and may be constituted by a planetary roller mechanism (traction drive), for example. In this case, the sun member 16, the planetary member 17, and the annular member 18 are respectively a sun roller, a planetary roller, and a ring roller on which the planetary roller rolls.

  As shown in FIGS. 1 and 2, the sun gear 16 is fixed to the small diameter portion 13 b of the intermediate shaft 13. The planetary gear 17 is rotatably supported by an annular support member 20. The support member 20 is provided with a plurality of support shafts 21 that can support the planetary gear 17. As shown in FIG. 1, the support shaft 21 rotatably supports the planetary gear 17 via a bearing 22. As shown in FIGS. 6 and 7, a total of six support shafts 21 are provided on the support member 20, of which three support shafts 21 support the three planetary gears 17 and the remaining three. The book support shaft 21 does not support the planetary gear 17. However, the number of the support shafts 21 varies depending on the design of the planetary gear 17 (or the planetary roller), and the number is not limited and may be any number.

  The annular member (internal gear) 18 is fixed to the casing 7 so as not to rotate. As shown in FIGS. 6 and 7, the annular member (internal gear) 18 has a plurality of through holes 18a formed at intervals in the circumferential direction. The annular member (internal gear) 18 is fixed to the casing 7 through the through hole 18a, as will be described later.

  The carrier 19 is located between the intermediate shaft 13 and the output shaft 3 of the first transmission mechanism 4 and is arranged coaxially therewith. The carrier 19 has a boss portion 19a and a flange portion 19b. The boss portion 19 a is configured to support a part of the third transmission mechanism 6. A protrusion 19c is formed at one end of the boss 19a in the axial direction, and a recess 19d is formed at the other end.

  The protrusion 19c is formed in a hemispherical shape having a spherical surface. The protrusion 19c is inserted into the recess 3c of the output shaft 3, and is in contact with the bottom surface (point contact). The concave portion 19d is formed in the center portion (axial center portion) of the end surface of the other end portion of the boss portion 19a. A bearing 23 (slide bearing) is attached to the recess 19d. The bearing 23 supports the small diameter portion 13 b of the intermediate shaft 13 in the first transmission mechanism 4. The protrusion 13e of the intermediate shaft 13 is in contact (point contact) with the bottom surface of the recess 19d. Further, the contact of the protrusion 19c may be supported by a general bearing.

  As shown in FIGS. 1 and 7, the flange portion 19b of the carrier 19 has a plurality of through holes 19e formed at intervals in the circumferential direction thereof. The carrier 19 is connected to the planetary gear 17 by inserting the support shaft 21 into the through hole 19e.

  The 3rd transmission mechanism 6 comprises a traction drive by the bearing structure (for example, cylindrical roller bearing) which supports the carrier 19 rotatably. As shown in FIGS. 1, 2, 8, and 9, the third transmission mechanism 6 is formed on the inner ring 24, the outer ring 25, the plurality of rolling elements 26, and the large-diameter portion 3 a of the output shaft 3. And a cage 27.

  The inner ring 24 is configured in an annular shape and is fixed to the boss portion 19 a of the carrier 19. The inner ring 24 has a raceway surface 24a on which the rolling element 26 can roll. The raceway surface 24a is configured in a straight line in a sectional view. The raceway surface 24a has a contact point CP1 with which the rolling element 26 can come into contact. The raceway surface 24a can be in line contact with the rolling element 26, but the contact point CP1 is an arbitrary point in the line contact portion.

  The outer ring 25 is configured in an annular shape and is fixed inside the casing 7. The outer ring 25 has a raceway surface 25a on which the rolling element 26 can roll. The raceway surface 24a is configured in a straight line in a sectional view. The raceway surface 25a has a contact point CP2 with which the rolling element 26 can come into contact. In addition, although the track surface 25a can be in line contact with the rolling element 26, the contact point CP2 is an arbitrary point in the part in line contact.

  Although the rolling element 26 is comprised with a cylindrical roller, it is not limited to this, You may comprise with a ball | bowl (sphere). As shown in FIG. 10, the diameter D2 of the rolling element 26 is such that the contact point CP1 on the raceway surface 24a of the inner ring 24 and the contact point CP2 on the raceway surface 25a of the outer ring 25 when the rolling element 26 is not incorporated. It is set larger than the distance L2 in the radial direction. This distance L2 corresponds to the difference between the radius of the raceway surface 9a of the inner ring 9 and the radius of the raceway surface 10a of the outer ring 10.

  As a result, when the rolling element 26 is incorporated between the inner ring 24 and the outer ring 25, the bearing internal clearance in this bearing structure becomes negative. Therefore, when the rolling element 26 is incorporated between the inner ring 24 and the outer ring 25, stress in a direction perpendicular to the axial direction can be generated on the inner ring 24, the outer ring 25, and the rolling element 26, and this can be applied as a preload. Thus, the preload mechanism 28 that applies preload to the third transmission mechanism 6 is configured by the dimensional relationship among the inner ring 24, the outer ring 25, and the rolling elements 26.

  As shown in FIGS. 8 and 9, the retainer 27 is formed integrally with the large diameter portion 3 a of the output shaft 3. The cage 27 has a notch 27 a that holds the rolling element 26. The cage 27 holds the plurality of rolling elements 26 at equal intervals by engaging the rolling elements 26 with the cutout portions 27a, and the rotational driving force due to the rolling (spinning and revolution) of the rolling elements 26, It also functions as a power transmission unit that transmits to the output shaft 3.

  As shown in FIG. 1, the casing 7 mainly includes a first component member 29 that supports the input shaft 2 and a second component member 30 that supports the output shaft 3.

  As shown in FIG. 1, the first component member 29 includes a boss portion 29a and a flange portion 29b. The boss portion 29 a holds the outer ring 10 of the first transmission mechanism 4 and the bearing 15 that supports the intermediate shaft 13 on its inner diameter surface. The flange portion 29b has a plurality of through holes 29c formed at equal intervals along the circumferential direction.

  As shown in FIG. 1, the second component member 30 includes a boss portion 30a and a flange portion 30b. An annular lid body 31 is fixed to the end surface of the boss portion 30a. Further, the boss portion 30 a holds the outer ring 25 in the third transmission mechanism 6 and the bearing 8 that supports the output shaft 3 on the inner diameter surface thereof. The flange portion 30b has screw holes 30c formed so as to penetrate at equal intervals along the circumferential direction.

  The first component member 29 and the second component member 30 are connected as follows. That is, the flange portions 29b and 30b are opposed to each other, and the annular member 18 is interposed between the flange portions 29b and 30b. At this time, the first through hole 29 c of the flange portion 29 b in the first component member 29, the through hole 18 a of the annular member 18, and the screw hole 30 c of the flange portion 30 b in the second component member 30 are matched. Further, a fixing member 32 such as a bolt is inserted into these holes 18a, 29c, 30c. By fastening the fixing member 32, the casing 7 is formed by integrally connecting the annular member 18 with the first component member 29 and the second component member 30 sandwiched therebetween. In the present embodiment, the outer diameter surface of the annular member 18 is configured to be flush with the outer surfaces of the flange portions 29b and 30b. However, the present invention is not limited to this. For example, the flange portion 30b of the second component member 30 is configured. By covering all the outer diameter surfaces of the annular member 18, the annular member 18 may be fixed to the flange portion 30b.

  Hereinafter, an operation mode of the composite transmission 1 (reduction gear) having the above-described configuration will be described.

  When the input shaft 2 is rotated by the drive source, the inner ring 9 of the first transmission mechanism 4 rotates together with the input shaft 2. Then, the rolling element 11 in contact with the raceway surface 9a of the inner ring 9 revolves around the input shaft 2 (large diameter portion 2a) while rotating along with the rotation of the inner ring 9. As the rolling element 11 revolves in this way, the notch 12 a of the cage 12 provided on the intermediate shaft 13 is driven by the rolling element 11. When the cage 12 rotates in accordance with the rolling of the rolling element 11, the intermediate shaft 13 rotates in the same direction as the input shaft 2 at a lower speed than the input shaft 2 at a constant reduction ratio.

  When the intermediate shaft 13 rotates, the sun gear 16 fixed to the intermediate shaft 13 rotates accordingly. When the sun gear 16 rotates, the planetary gear 17 revolves around the sun gear 16 while rotating between the sun gear 16 and the internal gear 18. The carrier 19 is driven by the support shaft 21 by the revolution of the planetary gear 17. As a result, the carrier 19 rotates in the same direction as the input shaft 2 at a constant reduction ratio and at a lower speed than the rotation speed of the intermediate shaft 13.

  In addition, the inner ring 24 of the third transmission mechanism 6 fixed to the carrier 19 rotates together with the carrier 19, and the rolling element 26 of the third transmission mechanism 6 rotates around the boss portion 19 a of the carrier 19 while rotating. To do. Due to the revolution of the rolling element 26, the cage 27 (large diameter portion 3a) of the output shaft 3 is driven. The rotation of the cage 27 causes the output shaft 3 to rotate in the same direction as the input shaft 2 at a constant reduction ratio and at a lower speed than the rotation speed of the carrier 19.

  According to the composite transmission 1 according to the present embodiment described above, the diameter D1 of the rolling element 11 in the first transmission mechanism 4 is set to be larger than the distance L1 between the contact points CP1 and CP2 in the inner ring 9 and the outer ring 10. The diameter D2 of the rolling element 26 in the third transmission mechanism 6 is set to be larger than the distance L2 between the contact points CP1 and CP2 on the inner ring 24 and the outer ring 25, and the rolling elements 11 and 26 are connected to the inner rings 9 and 24 and the respective rings. By disposing it between the outer rings 10 and 25, a suitable preload can be applied to each of the transmission mechanisms 4 and 6. Due to this preload, the rolling elements 26 are less likely to slip.

  Further, by applying preload to the first transmission mechanism 4 and the third transmission mechanism 6 only by the bearing structure, the preload mechanisms 14 and 28 can be simplified and the composite transmission 1 can be realized without using a separate mechanism. Can be miniaturized. Furthermore, since the composite transmission 1 is composed of a plurality of transmission mechanisms 4 to 6, it is possible to realize a larger transmission ratio (reduction ratio).

  FIG. 11 shows a second embodiment of the compound transmission according to the present invention. In the first embodiment, the composite transmission 1 is configured by the first transmission mechanism 4 to the third transmission mechanism 6, but in the present embodiment, the third transmission mechanism 6 is omitted.

  Similar to the first embodiment, the compound transmission 1 according to the present embodiment includes a first transmission mechanism including an input shaft 2, an output shaft 3, an inner ring 9, an outer ring 10, rolling elements 11, and an intermediate shaft 13. 4, a second transmission mechanism 5 including a sun gear 16, a planetary gear 17, an internal gear 18 and a carrier 19, a casing 7, and preload mechanisms 14 and 28.

  Similar to the first embodiment, the input shaft 2 has a large diameter portion 2 a and a small diameter portion 2 b and is supported by the first component member 29 of the casing 7 via the first transmission mechanism 4. The output shaft 3 has a large-diameter portion 3a and a small-diameter portion 3b as in the first embodiment. However, the output shaft 3 has a bearing 33 in a recess 3c formed on the end surface of the large-diameter portion 3a. Different.

  In the first embodiment, the protrusion 13e formed on the small-diameter portion 13b of the intermediate shaft 13 is in contact with the bottom surface of the concave portion 19d of the carrier 19 in the second transmission mechanism 5. However, in the present embodiment, the intermediate shaft 13 The protrusion 13e is not formed. The small diameter portion 13 b of the intermediate shaft 13 is supported by a bearing 33 provided in the concave portion 3 c of the output shaft 3.

  In the first embodiment, the through hole 29c is formed in the first component member 29 of the casing 7 and the screw hole 30c is formed in the second component member 30, but in this embodiment, the first component member 29 is screwed. A hole 29 c is formed, and a through hole 30 c is formed in the second component member 30.

  In the first embodiment, the cage 27 that holds the rolling elements 26 of the third transmission mechanism 6 is formed integrally with the large-diameter portion 3a of the output shaft 3, but in the present embodiment, the second transmission mechanism 5 is formed integrally with the large-diameter portion 3a of the output shaft 3. That is, in the first embodiment, the rotational driving force of the second transmission mechanism 5 (carrier 19) is indirectly transmitted to the output shaft 3 via the third transmission mechanism 6, but in the present embodiment, According to the configuration, the rotational driving force of the second transmission mechanism 5 is directly transmitted to the output shaft 3.

  Other configurations in the present embodiment are the same as those in the first embodiment, and common reference numerals are given to components common to the first embodiment.

  FIG. 12 shows a third embodiment of the compound transmission according to the present invention. The composite transmission 1 according to the present embodiment includes the first transmission mechanism 4 to the third transmission mechanism 6 as in the first embodiment. Among these, the position of the third transmission mechanism 6 is different from that of the first embodiment. Different. In the first embodiment, the third transmission mechanism 6 is provided between the output shaft 3 and the second transmission mechanism 5, but in the present embodiment, the first transmission mechanism 4 and the second transmission mechanism 5 It is provided in between.

  Similar to the first embodiment, the first transmission mechanism 4 includes an inner ring 9, an outer ring 10, a rolling element 11, and an intermediate shaft (hereinafter referred to as “first intermediate shaft”) 13 including a cage 12. Preload is applied to the first transmission mechanism 4 by the preload mechanism 14. The second transmission mechanism 4 includes a sun gear 16, a planetary member (planetary gear) 17, an annular member (internal gear) 18, and a carrier 19. The carrier 19 is integrated with the large diameter portion 3a of the output shaft 3 as in the second embodiment. A hole 19e is formed in the carrier 19, and the support shaft 21 of the second transmission mechanism 5 is engaged with the hole 19e.

  The third transmission mechanism 6 includes an inner ring 24, an outer ring 25, and a rolling element 26 as in the first embodiment. Preload is applied to the third transmission mechanism 6 by the preload mechanism 28. The inner ring 24 is fixed to the large diameter portion 13 a of the first intermediate shaft 13 in the first transmission mechanism 4. The outer ring 25 is fixed inside the first component member 29 in the casing 7.

  The third transmission mechanism 6 includes an intermediate shaft (hereinafter referred to as “second intermediate shaft”) 34 that engages with the rolling elements 26. The second intermediate shaft 34 is located between the first intermediate shaft 13 and the output shaft 3 and is arranged coaxially therewith. The second intermediate shaft 34 has a large diameter portion 34a at one end and a small diameter portion 34b at the other end. The large-diameter portion 34a integrally includes a retainer 27 (power transmission portion) that holds the rolling elements 26. The retainer 27 is formed with a notch 27 a for retaining the rolling element 26. A concave portion 34c that engages with the protruding portion 13e of the first intermediate shaft 13 is formed at the axial end of the large diameter portion 34a. The recess 34c is formed at the center (axial center) of the end surface of the large diameter portion 34a. The protrusion 13e of the first intermediate shaft 13 is in contact (point contact) with the bottom surface of the recess 34c.

  The small diameter portion 34b of the second intermediate shaft 34 has a protrusion 34d at one end thereof. The protrusion 34d is formed at the center (axial center) of the end surface of the small diameter portion 34b. The protrusion 34d is configured in a hemispherical shape having a spherical surface. The small diameter portion 34 b is supported by a bearing 33 fitted in the concave portion 3 c of the large diameter portion 3 a in the output shaft 3. The protrusion 34d of the small diameter portion 34b is in contact (point contact) with the bottom surface of the recess 3c.

  The casing 7 according to the present embodiment includes a first third component member 29, a second component member 30, a lid 31, and a cylindrical third component member 35 disposed between the first component member 29 and the internal gear 18. Is provided. The third component member 35 holds the outer ring 25 of the third transmission mechanism 6 in a non-rotatable manner on the inner diameter surface thereof. The third component member 35 has a plurality of through holes 35a formed at intervals in the circumferential direction. Each through hole 35 a is configured to coincide with the through hole 29 c of the first component member 29, the through hole 18 a of the internal gear 18, and the screw hole 30 c of the second component member 30. The third component member 35 is connected to the first component member 29 and the internal gear 18 through the through hole 35 a and the fixing member 32.

  Other configurations in the present embodiment are the same as those in the first embodiment, and common reference numerals are given to components common to the first embodiment.

  In addition, this invention is not limited to the structure of the said embodiment, Moreover, it is not limited to an above-described effect. The present invention can be variously modified without departing from the gist of the present invention.

  In the first embodiment, the example in which the first transmission mechanism 4 is a bearing structure using a deep groove ball bearing and the third transmission mechanism 6 is a bearing structure using a cylindrical roller bearing is shown, but the present invention is not limited to this. The first transmission mechanism 4 and the third transmission mechanism 6 may be of the same type of bearing structure, or may be constituted by bearings other than the bearings exemplified in the transmission mechanisms 4 and 6.

  In said 1st, 3rd embodiment, although the compound transmission 1 provided with the three transmission mechanisms 4-6 was illustrated, the number of transmission mechanisms is not limited to this. For example, the composite transmission 1 includes a fourth transmission mechanism including a planetary gear mechanism (or planetary roller mechanism) similar to the second transmission mechanism 5 and a fourth transmission mechanism having a bearing structure similar to the first transmission mechanism 4. May be constituted by a further multistage transmission mechanism. Moreover, you may comprise the 3rd transmission mechanism 6 by a planetary mechanism.

  That is, the compound transmission 1 according to the present invention includes a transmission mechanism (first transmission mechanism 4) including a cage 12 that holds the rolling element 11 on the intermediate shaft 13, and a transmission mechanism including a planetary gear mechanism or a planetary roller mechanism. (Second transmission mechanism 5) may be provided.

DESCRIPTION OF SYMBOLS 1 Compound transmission 2 Input shaft 3 Output shaft 4 1st transmission mechanism 5 2nd transmission mechanism 6 3rd transmission mechanism 9 Inner ring 10 of 1st transmission mechanism Outer ring 11 of 1st transmission mechanism Rolling body 13 of 1st transmission mechanism 1st Intermediate shaft 14 of transmission mechanism Preload mechanism
16 sun member 17 planetary member 18 annular member 24 inner ring 25 of third transmission mechanism outer ring 26 of third transmission mechanism rolling element 28 of third transmission mechanism preload mechanism 34 intermediate shaft (second intermediate shaft) of third transmission mechanism

Claims (7)

An input shaft;
An output shaft for outputting the rotational driving force input to the input shaft;
A first transmission mechanism that converts the rotational driving force of the input shaft at a predetermined gear ratio;
A second transmission mechanism that converts the rotational driving force transmitted from the first transmission mechanism at a predetermined gear ratio and transmits the converted force to the output shaft;
A preload mechanism for applying preload to the first transmission mechanism,
The first transmission mechanism is provided on the input shaft and rolls between an inner ring having a raceway surface, an outer ring having a raceway surface, and the raceway surface of the inner ring and the raceway surface of the outer ring. A plurality of rolling elements disposed; and an intermediate shaft that transmits the rotational driving force to the second transmission mechanism by engaging and rotating with the rolling elements,
The second transmission mechanism rotates by engaging with a sun member provided on the intermediate shaft, a planetary member engaging with the sun member, an annular member engaging with the planetary member, and the planetary member. A carrier for transmitting the rotational driving force to the output shaft by
The preload mechanism has a diameter of the rolling element greater than a distance between a contact point at which the rolling element contacts the raceway surface of the inner ring and a contact point at which the rolling element contacts the raceway surface of the outer ring. A compound transmission characterized by being configured to do so.   The intermediate shaft includes a power transmission unit that transmits the rotational driving force of the input shaft to the intermediate shaft by engaging with the rolling element and rotating, and the power transmission unit includes the rolling element. The composite transmission according to claim 1, wherein the compound transmission is a retainer.   A third transmission mechanism that is provided between the output shaft and the second transmission mechanism, and that converts the rotational driving force transmitted from the second transmission mechanism at a predetermined gear ratio and transmits it to the output shaft. The composite transmission according to claim 1, further comprising:   The third transmission mechanism is fixed to the carrier of the second transmission mechanism and has an inner ring having a raceway surface, an outer ring having a raceway surface, and between the raceway surface of the inner ring and the raceway surface of the outer ring. A plurality of rolling elements arranged to roll at a power, and a power transmission unit for transmitting the rotational driving force to the output shaft by engaging and rotating with the rolling elements, the power transmission The composite transmission according to claim 3, wherein the part is the retainer that retains the rolling elements, and is configured integrally with the output shaft.   The third transmission that is provided between the first transmission mechanism and the second transmission mechanism and that converts the rotational driving force of the first transmission mechanism at a predetermined speed ratio and transmits the converted torque to the second transmission mechanism. The composite transmission according to claim 1, further comprising a mechanism.   The third transmission mechanism includes an inner ring fixed to the intermediate shaft of the first transmission mechanism and having a raceway surface, an outer ring having a raceway surface, the raceway surface of the inner ring, and the raceway surface of the outer ring. A plurality of rolling elements arranged to roll between, and an intermediate shaft that transmits the rotational driving force of the first transmission mechanism to the second transmission mechanism by engaging and rotating with the rolling elements And a combined transmission according to claim 5. A preload mechanism for applying a preload to the third transmission mechanism, wherein the preload mechanism has a diameter of the rolling element in the third transmission mechanism, and the rolling element in the third transmission mechanism is connected to the raceway surface of the inner ring. The compound transmission according to claim 4 or 6, wherein the compound transmission is configured by setting the distance between a contact point that makes contact and a contact point at which the rolling element contacts the raceway surface of the outer ring.

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