JP2016118232A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission device capable of facilitating design and change of gear specifications and reducing a manufacturing cost.SOLUTION: A power transmission device 1 includes: a first sun wheel 10 and a second sun wheel 20; a first planetary wheel 31; a first wheel member 32 rotating integrally with the first planetary wheel 31; a second planetary wheel 41; a second wheel member 42 rotating integrally with the second planetary wheel 41; a transmission member 50 bridged between the outer periphery of the first wheel member 32 and the outer periphery of the second wheel member 42, and transmitting rotational power between the first wheel member 32 and the second wheel member 42; and a carrier 60 supporting the first planetary wheel 31 and the second planetary wheel 41 in a rotatable manner.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power transmission device that shifts and transmits rotational power using a planetary mechanism.

  For example, Patent Document 1 discloses a transmission that shifts rotational power using a planetary mechanism as a power transmission device. This transmission supports two sun gears (sun gear, ring gear), a stepped planetary gear (complex planetary gear) meshed with each sun gear, and a stepped planetary gear as transmission elements constituting the planetary mechanism. A carrier. Patent Document 2 discloses a power transmission device that employs a frictional planetary mechanism.

JP 2005-351295 A JP 2008-202707 A

  When changing the gear ratio in such a power transmission device, it is necessary to change the design of the gear specifications and the outer diameter of the friction wheel. Further, in the design change, it is not easy to set the gear specifications and the like so that at least a part of the transmission element constituting the planetary mechanism is diverted even after the change of the transmission gear ratio. Therefore, it is necessary to manufacture the transmission element again even if the transmission ratio is slightly changed, and there is a concern about an increase in manufacturing cost.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a power transmission device that facilitates the design and change of gear specifications and can reduce the manufacturing cost.

  (Claim 1) A power transmission device according to the present invention includes a first solar wheel and a second solar wheel arranged coaxially on a central axis, a first planetary wheel engaged with the first solar wheel, A first wheel member that rotates integrally with the first planetary wheel; a second planetary gear that engages with the second solar wheel; a second wheel member that rotates integrally with the second planetary wheel; A transmission member that is wound around the outer periphery of the one wheel member and the outer periphery of the second wheel member to transmit rotational power between the first wheel member and the second wheel member; the first planetary vehicle; And a carrier that rotatably supports the two planetary wheels.

  According to the first aspect of the present invention, the first planetary wheel and the second planetary wheel can transmit rotational power via the transmission member regardless of the inter-axis distance. That is, according to the power transmission device of the present invention, the degree of freedom in setting the distance between the axes of the transmission elements constituting the planetary mechanism is high, and the design change of the gear specifications can be facilitated. For this reason, the manufacturing cost of the power transmission device can be reduced by using a common transmission element before and after the change of the gear ratio, or by changing the design of a planetary wheel or wheel member with a relatively low manufacturing cost. Can do.

It is sectional drawing of the axial direction of the power transmission device in embodiment, and is II sectional drawing of FIG. It is II-II sectional drawing in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is IV-IV sectional drawing in FIG. It is a front view which shows a 1st carrier plate. It is Vb-Vb sectional drawing in FIG. 5A. It is VI-VI sectional drawing in FIG. It is a front view which shows a 2nd carrier plate. It is a VIIb-VIIb sectional view in Drawing 7A. It is VIII-VIII sectional drawing in FIG. It is sectional drawing of the axial direction of the power transmission device in the deformation | transformation aspect of embodiment, and is IX-IX sectional drawing of FIG. It is XX sectional drawing in FIG.

  Hereinafter, an embodiment in which a power transmission device of the present invention is embodied will be described with reference to the drawings. In the embodiment, the power transmission device exemplifies a configuration used in a reduction gear that decelerates and outputs a driving force input from a driving source using a planetary mechanism.

<Embodiment>
(Overall configuration of power transmission device 1)
The overall configuration of the power transmission device 1 according to the embodiment will be described with reference to FIGS. As shown in FIGS. 1 and 2, the power transmission device 1 includes a housing 2, an input shaft 3, an output shaft 4, a first sun gear 10, a second sun gear 20, and two first planets. The unit 30 includes two second planetary units 40, a toothed belt 50, and a carrier 60.

  The housing 2 is a fixing member that constitutes a part of the outer peripheral shape of the reduction gear. The input shaft 3 and the output shaft 4 are shaft members that are rotatably supported by the housing 2 around the central axis line Ac. One end of the input shaft 3 is connected to rotate integrally with an output shaft of a drive source such as an electric motor. The output shaft 4 outputs the driving force decelerated by the power transmission device 1.

  The first sun gear 10 (corresponding to the “first sun wheel” of the present invention) and the second sun gear 20 (corresponding to the “second sun wheel” of the present invention) are arranged coaxially on the central axis Ac. The In the present embodiment, the first sun gear 10 and the second sun gear 20 are internal gears in which internal teeth are formed on the inner peripheral surface. The first sun gear 10 is fixed to the housing 2. The second sun gear 20 is provided in the housing 2 so as to be rotatable relative to the first sun gear 10 around the central axis Ac. The second sun gear 20 is coupled to the output shaft 4 so as to rotate integrally with the output shaft 4. In the present embodiment, the second sun gear 20 is set to the same gear specifications as the first sun gear 10.

  As shown in FIGS. 2 and 3, each of the two first planetary units 30 is arranged at a circumferential position that is symmetric about the central axis Ac. The first planetary unit 30 is supported by a first carrier member 70 of a carrier 60 described later so as to be rotatable about a rotation axis Ar1 (two-dot chain line in FIG. 1). The first planetary unit 30 includes a first planetary gear 31 (corresponding to the “first planetary car” of the present invention), a first toothed pulley 32 (corresponding to the “first wheel member” of the present invention), The first planetary support shaft 33 and the key member 34 are included.

  As shown in FIG. 2, the first planetary gear 31 is an external gear having external teeth formed on the outer periphery, and engages with the first sun gear 10 by meshing. The first planetary gear 31 is formed with a through hole 31a penetrating in the direction of the rotation axis Ar1 at the center. The first planetary gear 31 is fixed to the outer peripheral surface of the first planetary support shaft 33 inserted through the through hole 31 a and rotates integrally with the first planetary support shaft 33.

  As shown in FIG. 3, the first toothed pulley 32 is an external gear in which external teeth are formed on the outer peripheral surface in the present embodiment. The first toothed pulley 32 meshes with the inner teeth 51 of the toothed belt 50. As shown in FIG. 1, the first toothed pulley 32 is arranged coaxially with the first planetary gear 31, and is restricted by the first planetary support shaft 33 from rotating about the rotation axis Ar <b> 1.

  Specifically, in the first toothed pulley 32, as shown in FIG. 3, a keyway 32 a formed on the inner peripheral surface of the first toothed pulley 32 is formed on the outer peripheral surface of the first planetary support shaft 33. It is arranged so as to face the key groove 33a. In this state, the first toothed pulley 32 is prevented from rotating with respect to the first planetary support shaft 33 by inserting the key member 34 into each of the key grooves 32a and 33a. Accordingly, the first toothed pulley 32 is connected to the first planetary gear 31 via the first planetary support shaft 33 and rotates integrally with the first planetary gear 31.

  As shown in FIGS. 3 and 4, each of the two second planetary units 40 is disposed at a circumferential position that is symmetric about the central axis Ac. The second planetary unit 40 is supported by a second carrier member 80 of the carrier 60 described later so as to be rotatable around the rotation axis Ar2 (two-dot chain line in FIG. 1). The second planetary unit 40 includes a second planetary gear 41 (corresponding to the “second planetary vehicle” of the present invention), a second toothed pulley 42 (corresponding to the “second wheel member” of the present invention), A second planetary support shaft 43 and a key member 44 are provided.

  As shown in FIG. 4, the second planetary gear 41 is an external gear having external teeth formed on the outer periphery, and engages with the second sun gear 20 by meshing. The second planetary gear 41 is formed with a through hole 41a penetrating in the direction of the rotation axis Ar2 at the center. The second planetary gear 41 is fixed to the outer peripheral surface of the second planetary support shaft 43 inserted through the through hole 41 a and rotates integrally with the second planetary support shaft 43. In the present embodiment, the second planetary gear 41 is set to the same gear specifications as the first planetary gear 31.

  As shown in FIG. 3, the second toothed pulley 42 is an external gear in which external teeth are formed on the outer peripheral surface in the present embodiment. As shown in FIGS. 1 and 3, the second toothed pulley 42 is disposed so that the position in the axial direction is the same as that of the first toothed pulley 32 in the central axis Ac direction. Similar to the first toothed pulley 32, the second toothed pulley 42 meshes with the inner teeth 51 of the toothed belt 50. As shown in FIG. 1, the second toothed pulley 42 is disposed coaxially with the second planetary gear 41, and is restricted by the second planetary support shaft 43 from rotating about the rotation axis Ar <b> 2.

  Specifically, as shown in FIG. 3, in the second toothed pulley 42, a keyway 42 a formed on the inner peripheral surface of the second toothed pulley 42 is formed on the outer peripheral surface of the second planetary support shaft 43. It is arranged so as to face the key groove 43a. In this state, the second toothed pulley 42 is prevented from rotating with respect to the second planetary support shaft 43 by inserting the key member 44 into each of the key grooves 42a and 43a. Accordingly, the second toothed pulley 42 is connected to the second planetary gear 41 via the second planetary support shaft 43 and rotates integrally with the second planetary gear 41. In the present embodiment, the number of teeth of the first toothed pulley 32 is set to a value different from the number of teeth of the second toothed pulley 42.

  The toothed belt 50 (corresponding to the “transmission member” of the present invention) is an endless belt member as shown in FIG. The toothed belt 50 is wound around the outer periphery of the first toothed pulley 32 and the outer periphery of the second toothed pulley 42, and transmits rotational power between the first toothed pulley 32 and the second toothed pulley 42. To do. The toothed belt 50 has internal teeth 51 that mesh with the first toothed pulley 32 and the second toothed pulley 42. In the present embodiment, the toothed belt 50 is formed of an elastic material such as rubber or resin having a relatively high hardness. Accordingly, the toothed belt 50 is configured to be able to absorb an impact in a rotating path direction.

  The carrier 60 is arranged coaxially with the input shaft 3. The carrier 60 rotatably supports the two first planetary units 30 and the two second planetary units 40 disposed at circumferential positions that are symmetrical about the central axis Ac. In the present embodiment, the carrier 60 is supported by the housing 2 so as to be rotatable about the central axis line Ac, and is connected to the input shaft 3. The detailed configuration of the carrier 60 will be described later.

(Detailed configuration of carrier 60)
A detailed configuration of the carrier 60 will be described with reference to FIGS. 1, 2, and 5 </ b> A to 8. The carrier 60 includes a center shaft member 61, fixing bolts 62 and 63, a first carrier member 70, and a second carrier member 80. As shown in FIG. 1, the first carrier member 70 rotatably supports two first planetary units 30 including a first planetary gear 31 and a first toothed pulley 32. The first carrier member 70 is supported so as to be rotatable relative to the housing 2.

  The first carrier member 70 includes a first carrier plate 71, a first carrier block 72, and a connection bolt 73 that are separate members. The first carrier plate 71 is disposed on the input side (left side in FIG. 1) of the power transmission device 1 with respect to the first planetary unit 30. The first carrier block 72 is disposed on the output side (right side in FIG. 1) of the power transmission device 1 with respect to the first planetary unit 30. That is, the first carrier plate 71 and the first carrier block 72 are arranged to face each other so as to sandwich the two first planetary units 30 from both sides in the central axis Ac direction.

  As shown in FIG. 5A, the first carrier plate 71 is formed with two shaft holes 71a penetrating in the direction of the rotation axis Ar1 at a circumferential position that is symmetric about the center axis Ac. As shown in FIG. 4, the first carrier block 72 has two shaft holes 72 a that are positioned coaxially with the two shaft holes 71 a of the first carrier plate 71. The first carrier plate 71 and the first carrier block 72 support the first planetary support shafts 33 of the two first planetary units 30 inserted into the respective shaft holes 71a and 72a so as to be rotatable around the rotation axis Ar1.

  As shown in FIGS. 2, 5A and 5B, the first carrier plate 71 is formed with two connecting portions 71b extending in the direction of the central axis line Ac on the surface facing the first carrier block 72. As shown in FIG. 2, each connecting portion 71 b is located between the first planetary gear 31 and the second carrier block 82 of the second carrier member 80 in the circumferential direction. Further, the first carrier block 72 is formed with two connecting portions 72b that are positioned coaxially with the two connecting portions 71b of the first carrier plate 71 (see FIG. 6).

  The first carrier plate 71 is inserted through the center of each of the connecting portions 71b and 72b in a state where the end surfaces of the two connecting portions 71b are in contact with the end surfaces of the two connecting portions 72b of the first carrier block 72. It is fixed by a bolt 73 (see FIG. 2). With such a configuration, the first carrier member 70 supports the first planetary unit 30 having the first planetary gear 31 meshing with the first sun gear 10 so as to be capable of rotating and revolving.

  As shown in FIG. 1, the second carrier member 80 rotatably supports two second planetary units 40 including a second planetary gear 41 and a second toothed pulley 42. The second carrier member 80 is rotatably supported by the housing 2 via the output shaft 4. Thereby, the second carrier member 80 is provided so as to be rotatable relative to the first carrier member 70 around the central axis Ac.

  The second carrier member 80 includes a second carrier plate 81, a second carrier block 82, and a connecting bolt 83 that are separate members. The second carrier plate 81 is disposed on the output side (right side in FIG. 1) of the power transmission device 1 with respect to the second planetary unit 40. The second carrier block 82 is disposed on the input side (left side in FIG. 1) of the power transmission device 1 with respect to the second planetary unit 40. That is, the second carrier plate 81 and the second carrier block 82 are arranged to face each other so as to sandwich the two second planetary units 40 from both sides in the central axis Ac direction.

  As shown in FIG. 7A, the second carrier plate 81 is formed with two shaft holes 81a penetrating in the direction of the rotation axis Ar2 at circumferential positions that are symmetrical about the center axis Ac. As shown in FIG. 2, the second carrier block 82 is formed with two shaft holes 82 a positioned coaxially with the two shaft holes 81 a of the second carrier plate 81. The second carrier plate 81 and the second carrier block 82 support the second planetary support shaft 43 of the two second planetary units 40 inserted into the respective shaft holes 81a and 82a so as to be rotatable around the rotation axis Ar2.

  As shown in FIGS. 4, 7 </ b> A, and 7 </ b> B, the second carrier plate 81 is formed with two connecting portions 81 b that extend in the direction of the central axis Ac on the surface facing the second carrier block 82. As shown in FIG. 4, each connecting portion 81 b is located between the second planetary gear 41 and the first carrier block 72 of the first carrier member 70 in the circumferential direction. Further, the second carrier block 82 is formed with two connecting portions 82b positioned coaxially with the two connecting portions 81b of the second carrier plate 81 (see FIG. 8).

  The second carrier plate 81 is inserted through the center of each of the connecting portions 81b and 82b with the end surfaces of the two connecting portions 81b in contact with the end surfaces of the two connecting portions 82b of the second carrier block 82. It is fixed by a bolt 83 (see FIG. 4). With such a configuration, the second carrier member 80 supports the second planetary unit 40 having the second planetary gear 41 meshing with the second sun gear 20 so as to be capable of rotating and revolving.

  Here, as described above, in the first planetary unit 30 and the second planetary unit 40, the toothed belt 50 is stretched around the outer periphery of the two first toothed pulleys 32 and the outer periphery of the two second toothed pulleys 42. Therefore, it is possible to transmit bidirectional rotational power. The tension state of the toothed belt 50 varies depending on the relationship with the length of the path of rotation of the toothed belt 50, as shown in FIG. The length of the path varies depending on the positional relationship between the two first toothed pulleys 32 and the two second toothed pulleys 42, that is, the distance between the axes (the distance between Ar1 and Ar2).

  More specifically, as viewed in the axial direction of FIG. 3, the length of the path of rotation of the toothed belt 50 (the toothed belt 50 as the virtual quadrangle Qv formed by the rotation axes Ar1 and Ar2 approaches the square. Required length). When the length of the path increases, the tension state of the toothed belt 50 that is set to a predetermined length in advance changes so that the tension becomes high.

  Therefore, for example, in the assembly process of the power transmission device 1, the first carrier member 70 and the second carrier member 80 are first centered by the central shaft member 61 disposed coaxially with the central axis Ac. Next, the second carrier member 80 is rotated relative to the first carrier member 70, and the inter-axis distance between the first toothed pulley 32 and the second toothed pulley 42 is changed with the rotation. Thereby, the tension state of the toothed belt 50 is adjusted.

  Thereafter, the first carrier member 70 and the second carrier member 80 are coupled in a state where a predetermined relative angle is maintained by fastening the fixing bolts 62 and 63. As described above, the carrier 60 (the central shaft member 61, the fixing bolts 62 and 63, the first carrier member 70, and the second carrier member 80) constitutes a tensioner mechanism that adjusts the tension state of the toothed belt 50.

(Operation of power transmission device 1 and change of gear ratio)
The power transmission device 1 having such a configuration is a planet having the first sun gear 10, the second sun gear 20, the first planetary unit 30, the second planetary unit 40, the toothed belt 50, and the carrier 60 as transmission elements. Provide mechanism. The planetary mechanism of the power transmission device 1 employs a meshing type in which each transmission element is engaged by meshing.

  In the power transmission device 1, when rotational power is input from the input shaft 3, the first planetary unit 30 and the second planetary unit 40 supported by the carrier 60 revolve. At this time, the first planetary unit 30 rotates at a rotational speed based on the number of teeth difference between the first sun gear 10 and the first planetary gear 31. The second planetary unit 40 that revolves in the same manner as the first planetary unit 30 receives the rotational power of the first planetary gear 31 via the toothed belt 50. At this time, the second planetary unit 40 rotates at a rotational speed based on the difference in the number of teeth between the first toothed pulley 32 and the second toothed pulley 42.

  The second sun gear 20 that meshes with the second planetary gear 41 receives rotational power from the second planetary unit 40 that rotates and rotates. The gear ratio of the power transmission device 1 is the difference in the number of teeth between the first sun gear 10 and the first planetary gear 31, the difference in the number of teeth between the first toothed pulley 32 and the second toothed pulley 42, the second planetary gear 41 and the first planetary gear 31. It is defined according to the difference in the number of teeth of the two sun gears 20. The rotational speed of the second sun gear 20 is the product of the transmission ratio of the power transmission device 1 and the rotational speed of the input shaft 3. The power transmission device 1 transmits the shifted rotational power to the output shaft 4 and outputs it.

  As described above, in the present embodiment, the first sun gear 10 and the second sun gear 20 are set to the same gear specifications, and the first planetary gear 31 and the second planetary gear 41 are set to the same gear specifications. Set to the original. Further, the number of teeth of the first toothed pulley 32 is set to a value different from the number of teeth of the second toothed pulley 42. Accordingly, when the power transmission device 1 transmits rotational power from the first toothed pulley 32 to the second toothed pulley 42 via the toothed belt 50, the first toothed pulley 32 and the second toothed pulley. Shifting is performed according to the difference in the number of teeth of 42.

  Further, in the power transmission device 1, it may be necessary to change the gear ratio. In such a case, generally, it is necessary to set the number of teeth of each gear so that the required gear ratio is obtained, and to set other gear specifications such as a twist angle and a shift coefficient. When the power transmission device adopts a planetary mechanism in which two sun gears and two planetary gears are meshed with each other, generally, a stepped planetary structure in which the two planetary gears are connected in a coaxial arrangement. A gear is employed (see Patent Document 1).

  In such a configuration, since the large and small planetary gears are integrally connected on the same axis, if the gear specifications of any of the transmission elements are changed, the inter-axis distance of each gear is changed in accordance with the change. . For this reason, there is a concern about an increase in manufacturing cost, such as the need to change the carrier design. On the other hand, the power transmission device 1 according to the present embodiment has the above-described configuration, and the first planetary gear 31 and the second planetary gear 41 are connected to each other via the toothed belt 50 regardless of the distance between the first planetary gear 31 and the second planetary gear 41. It becomes possible to transmit rotational power between the planetary gear 31 and the second planetary gear 41.

  Therefore, when it is necessary to change the gear ratio in the power transmission device 1, the gear ratio can be changed by exchanging the pulley with another first toothed pulley (or a second toothed pulley) having a different number of teeth, for example. . At this time, the route during rotation of the toothed belt 50 is changed, and the required length of the toothed belt 50 is changed. This can be dealt with by adjusting the tension state of the toothed belt 50 by changing the distance between the axes of the first toothed pulley 32 and the second toothed pulley 42 by the operation of the tensioner mechanism (carrier 60). Is possible.

  Further, in the power transmission device 1, a large change in the gear ratio (a change exceeding the change width of the gear ratio that can be handled by replacing the first toothed pulley 32 and the second toothed pulley 42) may be required. In order to cope with such a large change in the gear ratio, for example, the number of teeth of the first sun gear 10, the second sun gear 20, the first planetary gear 31, and the second sun gear 20 is changed. It is possible.

(Effects of the configuration of the embodiment)
The power transmission device 1 according to the embodiment includes a first toothed pulley 32 that rotates integrally with the first planetary gear 31, a second toothed pulley 42 that rotates integrally with the second planetary gear 41, And a toothed belt 50 that is wound around the outer periphery of the toothed pulley 32 and the outer periphery of the second toothed pulley 42 and transmits rotational power.

  According to such a configuration, the first planetary gear 31 and the second planetary gear 41 can transmit rotational power via the toothed belt 50 regardless of the inter-axis distance. That is, in the power transmission device 1 of the present embodiment, the degree of freedom in setting the distance between the axes of the transmission elements constituting the planetary mechanism is high, and the design and change of the gear specifications are facilitated. Therefore, a common transmission element is used before and after the change of the gear ratio, or a planetary vehicle (first planetary gear 31 and second planetary gear 41) or wheel member (first pulley 31 with first teeth, second gear with relatively low manufacturing cost). The manufacturing cost of the power transmission device 1 can be reduced by making the two-tooth pulley 42) a design change target.

  Further, each transmission element of the planetary mechanism of the power transmission device 1 has an external tooth or an internal tooth, and engages with the counterpart element by meshing. That is, the power transmission device 1 employs a meshing planetary mechanism. According to such a configuration, it is possible to transmit a strong rotational power as compared with the friction type planetary mechanism.

  In the present embodiment, the wheel members are the first toothed pulley 32 and the second toothed pulley 42. The transmission member is a toothed belt 50. According to such a configuration, a general-purpose toothed belt 50 can be applied to transmission of rotational power. Therefore, a dedicated transmission member is not necessary, and the manufacturing cost can be reduced.

  Furthermore, the toothed belt 50 is formed of an elastic material. According to such a configuration, an impact generated when the rotational power input to the power transmission device 1 fluctuates or reverses is buffered by the toothed belt 50 formed of an elastic material. Thereby, the load added to the transmission element which comprises a planetary mechanism with the said impact can be reduced, and durability of the power transmission device 1 can be improved.

  Further, the number of teeth of the first toothed pulley 32 is set to a value different from the number of teeth of the second toothed pulley 42. As a result, it is possible to shift gears when transmitting rotational power between the first toothed pulley 32 and the second toothed pulley 42. Therefore, it is possible to set a high gear ratio for the entire apparatus. Further, as in this embodiment, the first sun gear 10 and the second sun gear 20 are set to the same gear specifications, and the first planetary gear 31 and the second sun gear 20 are set to the same gear specifications. It is possible to change the speed even in such a configuration. That is, the power transmission device 1 can be configured using the first planetary gear 31 and the second planetary gear 41 as common parts, and the manufacturing cost of the device can be reduced.

  The second sun gear 20 is an internal gear that meshes with the second planetary gear 41 and is set to the same gear specifications as the first sun gear 10. According to such a configuration, since the first sun gear 10 and the second sun gear 20 are configured as internal gears, the gear ratio is increased as compared with a configuration in which at least one sun wheel is an external gear. can do. Also, the manufacturing cost of the internal gear is generally relatively higher than the manufacturing cost of the external gear. In particular, when forming internal gears set to different gear specifications, there is a concern that the manufacturing cost may be significantly increased depending on the processing method.

  However, in the planetary mechanism that employs the stepped planetary gear described above, the two planetary gears are connected in a coaxially arranged state, so the two sun gears are internal gears that have the same gear specifications. I can't. On the other hand, according to the configuration of the present embodiment, the first planetary gear 31 and the second planetary gear 41 are allowed to be arranged with a predetermined inter-axis distance. The gear 20 can be an internal gear having the same gear specifications. Therefore, the power transmission device 1 can reduce the manufacturing cost while increasing the gear ratio.

  Further, the carrier 60 rotates the second carrier member 80 relative to the first carrier member 70 to change the distance between the axes of the first toothed pulley 32 and the second toothed pulley 42, thereby providing a toothed belt. A tensioner mechanism for adjusting the tension state of 50 is configured. According to such a configuration, the power transmission device 1 can maintain a suitable operating environment by adjusting the tension state of the toothed belt 50 by the operation of the tensioner mechanism (carrier 60).

  Further, when the diameter of the planetary wheel (first planetary gear 31, second planetary gear 41) or wheel member (first toothed pulley 32, second toothed pulley 42) is changed due to a change in the gear ratio, etc. In this case, the rotation power can be transmitted between the transmission elements by the operation of the tensioner mechanism. Therefore, since the elements other than the exchanged elements to be exchanged can be used even after the change of the gear ratio, the manufacturing cost can be reduced.

<Modification of Embodiment>
(Planet mechanism of power transmission device 1)
In the embodiment, the transmission member that spans the outer periphery of the first toothed pulley 32 (first wheel member) and the outer periphery of the second toothed pulley 42 (second wheel member) includes the toothed belt 50 having the inner teeth 51. It is. The first and second wheel members are a first toothed pulley 32 and a second toothed pulley 42 that mesh with the inner teeth 51 of the toothed belt 50. On the other hand, in the power transmission device 1, the wheel member may be a sprocket and the transmission member may be a chain (including a roller chain and a silent chain). Even in such a configuration, the same effects as in the embodiment can be obtained.

  In the embodiment, the power transmission device 1 employs a meshing planetary mechanism in which transmission elements are engaged by meshing. On the other hand, the power transmission device 1 may employ a friction planetary mechanism in which transmission elements engage with each other by friction. Further, the power transmission device 1 may employ a planetary mechanism in which a meshing type and a friction type are appropriately combined. For example, between the first and second wheel members and the transmission member is engaged by friction, between the first solar vehicle and the first planetary vehicle, and between the second solar vehicle and the second planetary vehicle. May be engaged by engagement.

  In the embodiment, the transmission member is a toothed belt 50 which is an endless belt member. On the other hand, when the movable range of the power transmission device 1 is limited, the transmission member has an end portion that spans at least a part of the outer periphery of the first wheel member and the second wheel member. It is good also as a structure to have. Even in such a configuration, the same effects as in the embodiment can be obtained.

  Further, the power transmission device 1 includes one toothed belt 50 that is stretched over all of the two first toothed pulleys 32 and the two second toothed pulleys 42. On the other hand, you may arrange | position a some transmission member suitably so that rotational power may be transmitted between each wheel member. Specifically, the power transmission device 1 includes two toothed belts 50 each spanned on two sets of wheel members, one set of one toothed pulley 32 and one set of second toothed pulley 42. It is good also as a structure provided.

  Further, the transmission member may be configured to circumscribe the wheel member in addition to the configuration inscribed in the wheel member as in the embodiment when the transmission member is wound around the outer periphery of the plurality of wheel members. Specifically, the transmission member is a toothed belt having external teeth on the outer peripheral surface, and is inscribed with the two first toothed pulleys 32 and is in contact with the two second toothed pulleys 42. Even in such a configuration, the same effects as in the embodiment can be obtained.

  In the embodiment, the power transmission device 1 includes two first toothed pulleys 32 and two second toothed pulleys 42 as wheel members. On the other hand, if the power transmission device 1 has at least one first wheel member and one second wheel member, the total number of wheel members can be appropriately set. However, from the viewpoints of the maximum rotational power that can be transmitted and the balance of rotation, the configuration including the two wheel members exemplified in the embodiment is preferable.

(Planet mechanism gear specifications, etc.)
In the embodiment, the first sun gear 10 and the second sun gear 20 are set to the same gear specifications. On the other hand, the 1st sun gear 10 and the 2nd sun gear 20 are good also as a structure set to a different gear specification, taking into consideration the gear ratio required etc. However, from the viewpoint of reducing the manufacturing cost while making it possible to set a relatively large gear ratio, as illustrated in the embodiment, the first sun gear 10 and the second sun gear 20 have the same gear specifications. A configuration with a set internal gear is preferred. Similarly, the first planetary gear 31 and the second sun gear 20 may be configured to have different gear specifications. The first toothed pulley 32 and the second toothed pulley 42 may be set to the same gear specifications, and these may be used as common parts.

  In the embodiment, the first sun wheel (first sun gear 10) and the second sun wheel (second sun gear 20) are both internal gears as described above. On the other hand, the first solar wheel and the second solar wheel can adopt a configuration in which at least one of them is a circumscribed vehicle. In other words, when the planetary mechanism adopts the meshing type, for example, the first sun wheel may be an external gear that meshes with the first planetary gear 31 and the second sun wheel may be an external gear that meshes with the second planetary gear 41. Good. Further, one of the first sun wheel and the second sun wheel may be an internal gear, and the other may be an external gear. In any configuration, the first planetary vehicle and the second planetary vehicle are configured to be able to transmit rotational power via the transmission member, and the same effects as those of the embodiment can be obtained.

(Tensioner mechanism)
In the embodiment, the first carrier member 70 and the second carrier member 80 are structured to be relatively rotatable so that the carrier 60 changes the interaxial distance between the first toothed pulley 32 and the second toothed pulley 42. The mechanism was configured. In contrast, the power transmission device may include a tensioner mechanism that adjusts the tension state of the transmission member (toothed belt 50) without depending on the relative rotation of the first carrier member 70 and the second carrier member 80. Good.

  Specifically, the power transmission device 101 includes a carrier 160 and a tensioner mechanism 190 as shown in FIGS. 9 and 10. As shown in FIG. 10, the carrier 160 rotatably supports the two first planetary units 30 and the two second planetary units 40 that are alternately arranged around the central axis Ac at equal intervals. The first carrier plate 71 of the first carrier member 70 is coupled to the first carrier block 72 and coupled to the second carrier block 82 of the second carrier member 80 disposed adjacent to the central axis Ac direction. Is done.

  The second carrier plate 81 of the second carrier member 80 is connected to the second carrier block 82 and is connected to the second carrier block 72 arranged adjacent to the central axis Ac direction. Thereby, the 1st carrier member 70 and the 2nd carrier member 80 are connected in the state which supported the 1st planetary unit 30 and the 2nd planetary unit 40 so that relative rotation is impossible.

  As shown in FIG. 10, the tensioner mechanism 190 is provided on one of the two connecting portions 71 b (72 b) of the first carrier member 70. In the tensioner mechanism 190, the roller 191 moves in the radial direction of the power transmission device 101 in accordance with the tightening state of an adjustment bolt (not shown) from the outside. Thereby, the path | route at the time of rotation of the toothed belt 50 circumscribing the roller 191 is changed, and the required length of the toothed belt 50 changes. Thereby, the tension state of the toothed belt 50 is adjusted. Even in such a configuration, the same effects as in the embodiment can be obtained. However, from the viewpoint of reducing the number of parts, a configuration in which the carrier 60 functions as a tensioner mechanism is preferable as illustrated in the embodiment.

<Appendix>
The power transmission devices 1 and 101 are engaged with the first sun wheel and the first sun wheel (first sun gear 10) and the second sun wheel (second sun gear 20) that are coaxially disposed on the central axis Ac. First planetary gear (first planetary gear 31), first wheel member (first pulley 32 with teeth) that rotates integrally with the first planetary gear, and second planetary gear that engages with the second solar wheel (Second planetary gear 41), a second wheel member (second pulley 42 with teeth) that rotates integrally with the second planetary gear, and the outer periphery of the first wheel member and the outer periphery of the second wheel member. A transmission member (toothed belt 50) for transmitting rotational power between the first wheel member and the second wheel member, and carriers 60 and 160 for rotatably supporting the first planetary vehicle and the second planetary vehicle, .

  According to such a configuration, the first planetary gear (first planetary gear 31) and the second planetary gear (second planetary gear 41) are connected to each other via the transmission member (toothed belt 50) regardless of the inter-axis distance. Rotational power can be transmitted. That is, according to the above configuration, the degree of freedom in setting the distance between the axes of the transmission elements constituting the planetary mechanism is high, and the design and change of the gear specifications are easy. Therefore, a common transmission element is used before and after the change of the gear ratio, or a planetary vehicle (first planetary gear 31 and second planetary gear 41) or wheel member (first pulley 31 with first teeth, second gear with relatively low manufacturing cost). The manufacturing cost of the power transmission device 1 can be reduced by making the two-tooth pulley 42) a design change target.

The first wheel member (first toothed pulley 32) and the second wheel member (second toothed pulley 42) are external gears. The transmission member (toothed belt 50) has internal teeth 51 that mesh with the first wheel member and the second wheel member.
According to such a configuration, the power transmission device 1 employs a meshing planetary mechanism. Therefore, the power transmission device 1 can transmit stronger rotational power than the friction planetary mechanism.

The first wheel member and the second wheel member are toothed pulleys (first toothed pulley 32, second toothed pulley 42). The transmission member is a toothed belt 50 that meshes with a toothed pulley and is formed of an elastic material.
According to such a configuration, an impact generated when the rotational power input to the power transmission device 1 fluctuates or reverses is buffered by the toothed belt 50 formed of an elastic material. Thereby, the load added to the transmission element which comprises a planetary mechanism with the said impact can be reduced, and durability of the power transmission device 1 can be improved.

The first wheel member and the second wheel member are sprockets. The transmission member is a chain that meshes with the sprocket.
According to such a configuration, a general-purpose chain can be applied as a transmission member to transmit rotational power. Therefore, a dedicated transmission member is not necessary, and the manufacturing cost can be reduced.

The number of teeth of the first wheel member (the first toothed pulley 32) is set to a value different from the number of teeth of the second wheel member (the second toothed pulley 42).
Thereby, it becomes possible to change the speed when the rotational power is transmitted between the first wheel member (the first toothed pulley 32) and the second wheel member (the second toothed pulley 42). Therefore, it is possible to set a high gear ratio for the entire apparatus. The first sun wheel (first sun gear 10) and the second sun wheel (second sun gear 20) are set to the same gear specifications, and the first planetary wheel (first planetary gear 31) and the second sun wheel are set. Even in a configuration in which the planetary wheel (second sun gear 20) has the same gear specifications, the speed can be changed. That is, it is possible to configure the power transmission device 1 using the first planetary gear (first planetary gear 31) and the second planetary gear (second planetary gear 41) as common parts, and the manufacturing cost of the device can be reduced.

The first planetary gear (first planetary gear 31) and the second planetary gear (second planetary gear 41) are external gears. The first sun wheel (first sun gear 10) is an internal gear that meshes with the first planetary wheel. The second sun wheel (second sun gear 20) is an internal gear that meshes with the second planetary wheel and is set to the same gear specifications as the first sun wheel.
According to such a configuration, since the first sun wheel (first sun gear 10) and the second sun wheel (second sun gear 20) are configured to be internal gears, at least one of the sun wheels is The gear ratio can be increased as compared with a configuration that is an external gear. In addition, since the first planetary gear (first planetary gear 31) and the second planetary gear (second planetary gear 41) are allowed to be arranged with a predetermined inter-axis distance, The gear 10) and the second sun wheel (second sun gear 20) can be internal gears having the same gear specifications. Therefore, the power transmission device 1 can reduce the manufacturing cost while increasing the gear ratio.

The carrier 60 is centered with respect to the first carrier member 70 and a first carrier member 70 that rotatably supports the first planetary wheel (first planetary gear 31) and the first wheel member (first toothed pulley 32). A second carrier member 80 provided so as to be relatively rotatable about an axis Ac and rotatably supporting a second planetary gear (second planetary gear 41) and a second wheel member (second toothed pulley 42). . The carrier 60 rotates the second carrier member 80 relative to the first carrier member 70 to change the inter-axis distance between the first wheel member and the second wheel member, whereby the transmission member (the toothed belt 50). A tensioner mechanism for adjusting the tension state is configured.
According to such a configuration, the power transmission device 1 can maintain a suitable operating environment by adjusting the tension state of the transmission member (toothed belt 50) by the operation of the tensioner mechanism (carrier 60). Further, when the diameter of the planetary wheel (first planetary gear 31, second planetary gear 41) or wheel member (first toothed pulley 32, second toothed pulley 42) is changed due to a change in the gear ratio, etc. In this case, the rotation power can be transmitted between the transmission elements by the operation of the tensioner mechanism. Therefore, since components other than the exchanged elements to be exchanged can be used even after the change of the gear ratio, the manufacturing cost can be reduced.

  1, 101: Power transmission device, 10: First sun gear (first sun wheel), 20: Second sun gear (second sun wheel), 30: First planetary unit, 31: First planetary gear (first Planetary wheel), 32: first toothed pulley (first wheel member), 40: second planetary unit, 41: second planetary gear (second planetary wheel), 42: second toothed pulley (first wheel member) ), 50: toothed belt (transmission member), 51: internal teeth, 60, 160: carrier (tensioner mechanism), 70: first carrier member, 80: second carrier member, Ac: central axis

Claims (7)

A first solar wheel and a second solar wheel arranged coaxially on the central axis;
A first planetary gear engaging the first solar wheel;
A first wheel member that rotates integrally with the first planetary vehicle;
A second planetary gear engaged with the second solar wheel;
A second wheel member that rotates integrally with the second planetary vehicle;
A transmission member that is wound around the outer periphery of the first wheel member and the outer periphery of the second wheel member, and transmits rotational power between the first wheel member and the second wheel member;
A carrier that rotatably supports the first planetary wheel and the second planetary vehicle;
A power transmission device comprising: The first wheel member and the second wheel member are external gears,
The power transmission device according to claim 1, wherein the transmission member has internal teeth that mesh with the first wheel member and the second wheel member. The first wheel member and the second wheel member are toothed pulleys;
The power transmission device according to claim 2, wherein the transmission member is a toothed belt that meshes with the toothed pulley and is formed of an elastic material. The first wheel member and the second wheel member are sprockets,
The power transmission device according to claim 2, wherein the transmission member is a chain that meshes with the sprocket.   5. The power transmission device according to claim 2, wherein the number of teeth of the first wheel member is set to a value different from the number of teeth of the second wheel member. The first planetary vehicle and the second planetary vehicle are external gears,
The first sun wheel is an internal gear that meshes with the first planetary wheel,
The second sun wheel is an internal gear that meshes with the second planetary wheel and is set to the same gear specifications as the first sun wheel. Power transmission device. The carrier is
A first carrier member rotatably supporting the first planetary wheel and the first wheel member;
A second carrier member provided so as to be relatively rotatable around the central axis with respect to the first carrier member, and rotatably supporting the second planetary wheel and the second wheel member;
A tensioner mechanism that adjusts the tension state of the transmission member by changing the inter-axis distance between the first wheel member and the second wheel member by rotating the second carrier member relative to the first carrier member. The power transmission device according to any one of claims 1 to 6, comprising:

Images