Power conversion device and power generation device including the same

Abstract

To provide a power conversion device which can properly support a load biased in an axial direction in a planetary gear even when the load is applied and a power generation device including the power conversion device.SOLUTION: A radius r1 of a ring gear RG which is a fixed internal gear is twice a radius r2 of a planetary gear PG rotating integrally with a crank member 2. A first planetary bearing B11 and a second planetary bearing B12 which support the planetary gear PG with respect to a carrier CR are separately arranged on both sides in an axial direction L with respect to a tooth section PGa of the planetary gear PG. A first carrier bearing B21 and a second carrier bearing B22 which support the carrier CR with respect to a ring gear RG are separately arranged on both the sides in the axial direction L with respect to the tooth section RGa of the ring gear RG. The first carrier bearing B21 overlaps a moving locus of the first planetary bearing B11 involved in revolution of the planetary gear PG when viewed in a radial direction. The second carrier bearing B22 overlaps a moving locus of the second planetary bearing B12 involved in revolution of the planetary gear PG when viewed in the radial direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power conversion device that converts reciprocating motion into rotational motion, and a power generation device equipped with the same.

Background Art

[0002] Patent Document 1 discloses a power conversion device (1) that converts the reciprocating motion of an input member (24) into the rotational motion of an output member (10) by means of a planetary gear mechanism (4). The planetary gear mechanism (4) includes a ring gear (20) that is a fixed internal gear, a planetary gear (21) that meshes with the ring gear, and a carrier that rotatably supports the planetary gear. Note that the reference numerals shown in parentheses in the description of the background art are those of Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power conversion device (1) of Patent Document 1, the input member (24) is arranged so as to protrude from one side in the axial direction (the left side in FIG. 3 of Patent Document 1) of the planetary gear (21). Further, the carrier includes a shaft portion (12) that rotatably supports the planetary gear (21) from the inner side in the radial direction, and a connecting portion (11) that is arranged on the other side in the axial direction (the right side in FIG. 3 of Patent Document 1) with respect to the planetary gear (21) and connects the shaft portion (12) and the output member (10).

[0005] In such a configuration, it is difficult to ensure the support rigidity of the planetary gear (21). Therefore, when the load input from the input member (24) acts on the planetary gear (21) in a state where the load is biased in the axial direction, the load cannot be properly supported.

[0006] Therefore, even when an axially offset load acts on the planetary gear, it is desirable to realize a technology capable of appropriately supporting the load.

Means for Solving the Problem

[0007] In view of the above, the characteristic configuration of the power transmission device is as follows. A planetary gear mechanism including a ring gear that is a fixed internal gear, a planetary gear that meshes with the ring gear, and a carrier that rotatably supports the planetary gear; A crank member that is disposed so as to extend in the planetary radial direction orthogonal to the planetary axis, which is the rotation axis of the planetary gear, and is connected so as to rotate integrally with the planetary gear; An input member that is supported by the crank member and is disposed on an input axis that is separated from the planetary axis in the planetary radial direction; An output member that is connected to a specific rotating member that rotates in conjunction with the carrier, excluding the planetary gear, and The radius of the ring gear is twice the radius of the planetary gear, Taking the direction along the carrier axis, which is the rotation axis of the carrier, as the axial direction and the direction orthogonal to the carrier axis as the radial direction, A first planetary bearing and a second planetary bearing that rotatably support the planetary gear with respect to the carrier are disposed separately on both sides in the axial direction with respect to the tooth portion of the planetary gear, A first carrier bearing and a second carrier bearing that rotatably support the carrier with respect to the ring gear are disposed separately on both sides in the axial direction with respect to the tooth portion of the ring gear, The first carrier bearing is disposed so as to overlap the movement locus of the first planetary bearing accompanying the revolution of the planetary gear in a radial view along the radial direction, The second carrier bearing is disposed so as to overlap the movement locus of the second planetary bearing accompanying the revolution of the planetary gear in the radial view.

[0008] According to this characteristic configuration, the planetary gear is rotatably supported with respect to the carrier by a first planetary bearing and a second planetary bearing that are separately arranged on both axial sides with respect to the tooth portion of the planetary gear. Further, the carrier is rotatably supported with respect to the ring gear by a first carrier bearing and a second carrier bearing that are separately arranged on both axial sides with respect to the tooth portion of the ring gear. Thereby, it is easy to ensure the support rigidity of the planetary gear. Therefore, even when an axially biased load acts on the planetary gear, the load can be appropriately supported. Also, according to this characteristic configuration, the first carrier bearing overlaps with the movement locus of the first planetary bearing accompanying the revolution of the planetary gear in a radial view, and the second carrier bearing overlaps with the movement locus of the second planetary bearing accompanying the revolution of the planetary gear in a radial view. Therefore, it is easy to keep the axial dimension of the power conversion device small.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0010] 1. First Embodiment Hereinafter, the power conversion device 10 according to the first embodiment will be described with reference to FIG. 1. As shown in FIG. 1, the power conversion device 10 includes a planetary gear mechanism 1, a crank member 2, an input member 3, and an output member 4.

[0011] The planetary gear mechanism 1 includes a ring gear RG, a planetary gear PG, and a carrier CR. The ring gear RG is an internal gear fixed non-rotatably. The planetary gear PG meshes with the ring gear RG. The carrier CR rotatably supports the planetary gear PG.

[0012] The radius r1 of the ring gear RG is twice the radius r2 of the planetary gear PG. Here, in the present application, the "radius of the gear" means the radius of the pitch circle of the gear.

[0013] In the following description, the direction along the carrier axis X1, which is the rotation axis of the carrier CR, is defined as the "axial direction L". One side of the axial direction L is defined as the "first axial side L1", and the other side of the axial direction L is defined as the "second axial side L2". Further, the direction orthogonal to the carrier axis X1 is defined as the "radial direction R". Also, the direction orthogonal to the planetary axis X2, which is the rotation axis of the planetary gear PG, is defined as the "planetary radial direction Rp".

[0014] The planetary gear mechanism 1 includes a first planetary bearing B11 and a second planetary bearing B12, and a first carrier bearing B21 and a second carrier bearing B22.

[0015] The first planetary bearing B11 and the second planetary bearing B12 are bearings that rotatably support the planetary gear PG with respect to the carrier CR. The first planetary bearing B11 and the second planetary bearing B12 are arranged on both sides in the axial direction L with respect to the planetary gear tooth portion PGa, which is the tooth portion of the planetary gear PG. In the example shown in FIG. 1, as the first planetary bearing B11 and the second planetary bearing B12, for example, relatively thin bearings (bearings with small dimensions in the planetary radial direction Rp) such as needle roller bearings and sliding bearings are used.

[0016] The first carrier bearing B21 and the second carrier bearing B22 are bearings that rotatably support the carrier CR with respect to the ring gear RG. The first carrier bearing B21 and the second carrier bearing B22 are arranged on both sides in the axial direction L with respect to the ring gear tooth portion RGa, which is the tooth portion of the ring gear RG. In the example shown in FIG. 1, ball bearings are used as the first carrier bearing B21 and the second carrier bearing B22.

[0017] The first carrier bearing B21 is arranged so as to overlap with the movement locus of the first planetary bearing B11 accompanying the revolution of the planetary gear PG in a radial view along the radial direction R. The second carrier bearing B22 is arranged so as to overlap with the movement locus of the second planetary bearing B12 accompanying the revolution of the planetary gear PG in a radial view along the radial direction R. Here, regarding the arrangement of the two elements, "overlapping in a specific direction view" means that when a virtual straight line parallel to the line-of-sight direction is moved in each direction orthogonal to the virtual straight line, there is at least a part of the region where the virtual straight line intersects both of the two elements.

[0018] In the present embodiment, the planetary gear PG includes a shaft portion 11 extending along the axial direction L. The shaft portion 11 is connected so as to rotate integrally with the planetary gear tooth portion PGa. The shaft portion 11 is arranged so as to extend to both sides in the axial direction L with respect to the planetary gear tooth portion PGa. The portion of the shaft portion 11 extending from the planetary gear tooth portion PGa to the first axial side L1 in the axial direction is rotatably supported with respect to the carrier CR via the first planetary bearing B11. The portion of the shaft portion 11 extending from the planetary gear tooth portion PGa to the second axial side L2 in the axial direction is rotatably supported with respect to the carrier CR via the second planetary bearing B12. In the example shown in FIG. 1, the entire planetary gear PG including the planetary gear tooth portion PGa and the shaft portion 11 is integrally formed.

[0019] In the present embodiment, the ring gear RG includes a first support portion 12 and a second support portion 13 extending to both sides in the axial direction L with respect to the ring gear tooth portion RGa. The first support portion 12 supports the first carrier bearing B21 from the outside in the radial direction R. The second support portion 13 supports the second carrier bearing B22 from the outside in the radial direction R. Each of the first support portion 12 and the second support portion 13 is formed in a cylindrical shape with the carrier axis X1 as the axis.

[0020] In this embodiment, the first support portion 12 is arranged so as to overlap with the movement locus of the first planetary bearing B11 accompanying the revolution of the planetary gear PG in a radial view along the radial direction R. Further, the second support portion 13 is arranged so as to overlap with the movement locus of the second planetary bearing B12 accompanying the revolution of the planetary gear PG in a radial view along the radial direction R.

[0021] As shown in FIG. 1, the crank member 2 is arranged to extend in the planetary radial direction Rp. The crank member 2 extends across the planetary axis X2 and the input axis X3 spaced apart from the planetary axis X2 in the planetary radial direction Rp. The crank member 2 is connected so as to rotate integrally with the planetary gear PG. In this embodiment, the crank member 2 is connected to be non-rotatable relative to the portion on the first axial side L1 of the shaft portion 11 of the planetary gear PG with respect to the first planetary bearing B11.

[0022] The input member 3 is arranged on the input axis X3. The input member 3 is supported by the crank member 2. In this embodiment, the input member 3 is a shaft member arranged to protrude from the crank member 2 toward the first axial side L1. And the input member 3 is connected so as to rotate integrally with the crank member 2.

[0023] The output member 4 is connected to the specific rotating member RT. The specific rotating member RT is a rotating member excluding the planetary gear PG and rotates in conjunction with the carrier CR. In this embodiment, the specific rotating member RT is the carrier CR. Here, "rotating in conjunction" includes rotating at the same speed and rotating at a predetermined speed ratio, regardless of the rotation direction.

[0024] In this embodiment, the output member 4 is a shaft member arranged on the carrier axis X1. Further, in this embodiment, the output member 4 is arranged to protrude from the carrier CR toward the second axial side L2. And the output member 4 is connected so as to rotate integrally with the carrier CR.

[0025] In the power conversion device 10 configured as described above, when a predetermined driving force is input to the input member 3, the input member 3 performs a reciprocating motion with reference to the carrier axis X1. Along with this, the output member 4 rotates about the carrier axis X1.

[0026] In the present embodiment, the radius r2 of the planetary gear PG and the distance d between the planetary axis X2 and the input axis X3 in the planetary radial direction Rp are the same. Therefore, the movement locus of the input member 3 in the reciprocating motion is linear along the axial direction L in the axial view passing through the carrier axis X1. In the following description, the direction along the linear movement locus of the input member 3 in the reciprocating motion is defined as the "input direction I".

[0027] 2. Second Embodiment Hereinafter, the power conversion device 10 according to the second embodiment will be described with reference to FIG. 2. In the present embodiment, mainly the configuration of the planetary gear mechanism 1 is different from that of the first embodiment. Hereinafter, the description will focus on the differences from the first embodiment. For points not particularly described, the same as the first embodiment will be assumed.

[0028] As shown in FIG. 2, in the present embodiment, in addition to the large-diameter planetary gear PGL as the planetary gear PG, a small-diameter planetary gear PGS and a sun gear SG are further provided.

[0029] The small-diameter planetary gear PGS has a smaller radius than the large-diameter planetary gear PGL. The small-diameter planetary gear PGS is connected so as to rotate integrally with the large-diameter planetary gear PGL. In the present embodiment, the small-diameter planetary gear PGS is disposed on the second side L2 in the axial direction with respect to the large-diameter planetary gear PGL. And the small-diameter planetary gear PGS is connected so as to rotate integrally with the shaft portion 11.

[0030] In this embodiment, a portion of the shaft portion 11 that extends from the tooth portion of the large-diameter planetary gear PGL (planetary gear tooth portion PGa) in the axial direction to the first side L1 is rotatably supported with respect to the carrier CR via the first planetary bearing B11. A portion of the shaft portion 11 that extends from the tooth portion of the small-diameter planetary gear PGS in the axial direction to the second side L2 is rotatably supported with respect to the carrier CR via the second planetary bearing B12. In the example shown in FIG. 2, ball bearings are used as the first planetary bearing B11 and the second planetary bearing B12.

[0031] The sun gear SG is disposed on the carrier axis X1. The sun gear SG meshes with the small-diameter planetary gear PGS. The sun gear SG is connected so as to rotate integrally with the output member 4. Thus, in this embodiment, the specific rotating member RT is the sun gear SG.

[0032] In this embodiment, the output member 4 is a shaft member disposed so as to protrude from the sun gear SG in the axial direction to the second side L2. The output member 4 is rotatably supported with respect to the carrier CR via a pair of output bearings B3.

[0033] In this embodiment, the rotation of the carrier CR in the planetary gear mechanism 1 is speed-changed and transmitted to the output member 4. In this embodiment, by appropriately adjusting the ratio of the radius of the small-diameter planetary gear PGS to the radius of the sun gear SG, the planetary gear mechanism 1 can function as a speed reducer or a speed increaser, and the speed ratio can be changed.

[0034] 3. Third Embodiment Hereinafter, the power conversion device 10 according to the third embodiment and the power generation device 100 including the same will be described with reference to FIG. 3. In the power conversion device 10 according to this embodiment, mainly the support configuration of the output member 4 is different from that of the second embodiment. Hereinafter, the description will focus on the differences from the second embodiment. Note that, for points not particularly described, the same applies as in the second embodiment.

[0035] The power generation device 100 includes a rotating electrical machine 5. In the present embodiment, the power generation device 100 further includes a case 6.

[0036] The rotating electrical machine 5 includes a stator 51 and a rotor 52. The stator 51 is fixed to a non-rotating member. In the present embodiment, the stator 51 is fixed to the case 6 as a non-rotating member. The rotor 52 is rotatably supported with respect to the stator 51. In the present embodiment, the stator 51 and the rotor 52 are arranged on the carrier axis X1. And the rotor 52 is arranged inside the stator 51 in the radial direction R.

[0037] The rotor 52 is connected so as to rotate integrally with the output member 4. In the present embodiment, the rotor 52 is connected to the output member 4 via a rotor support member 7. The rotor support member 7 is formed so as to extend along the radial direction R. In the present embodiment, the rotor support member 7 is arranged so as to extend outward in the radial direction R from the output member 4 between the axial directions L of the pair of output bearings B3. And the rotor support member 7 supports the rotor 52 from the inside in the radial direction R.

[0038] The case 6 houses the rotating electrical machine 5. In the present embodiment, the ring gear RG is fixed to the case 6. Also, in the present embodiment, the output member 4 is rotatably supported with respect to the case 6 via a pair of output bearings B3.

[0039] In the present embodiment, the reciprocating motion of the input member 3 is converted into the rotational motion of the output member 4 by the power conversion device 10. Along with this, the rotor 52 of the rotating electrical machine 5 rotates integrally with the output member 4. As a result, the rotating electrical machine 5 generates electricity by the driving force transmitted to the rotor 52.

[0040] In this embodiment, the power conversion device 10 is disposed inside the stator 51 in the radial direction R and at a position overlapping the stator 51 in a radial view along the radial direction R. In the example shown in FIG. 3, the planetary gear mechanism 1 and the output member 4 of the power conversion device 10 are disposed so as to overlap the stator 51 in a radial view along the radial direction R.

[0041] In this embodiment, the portion between the large-diameter planetary gear PGL and the small-diameter planetary gear PGS on the shaft portion 11 is rotatably supported with respect to the carrier CR via the second planetary bearing B12. In the example shown in FIG. 3, as the first planetary bearing B11 and the second planetary bearing B12, relatively thin bearings (with small dimensions in the planetary radial direction Rp), such as needle roller bearings and sliding bearings, are used.

[0042] 4. Fourth Embodiment Hereinafter, the power conversion device 10 according to the fourth embodiment and the power generation device 100 including the same will be described with reference to FIG. 4. In the power conversion device 10 according to this embodiment, mainly the configuration of the planetary gear mechanism 1, the number of crank members 2, and the number of input members 3 are different from those of the first embodiment. Hereinafter, the description will focus on the differences from the first embodiment. Note that points not particularly described are the same as those in the first embodiment.

[0043] As shown in FIG. 4, in this embodiment, the ring gear RG includes a first ring gear RG1 and a second ring gear RG2. The first ring gear RG1 and the second ring gear RG2 are disposed at different positions in the axial direction L. In this embodiment, the first ring gear RG1 is disposed on the first side L1 in the axial direction with respect to the second ring gear RG2.

[0044] In this embodiment, the planetary gear PG includes a first planetary gear PG1 and a second planetary gear PG2. The first planetary gear PG1 meshes with a first ring gear RG1. The second planetary gear PG2 meshes with a second ring gear RG2. In this embodiment, the first planetary gear PG1 and the second planetary gear PG2 are helical gears whose tooth surfaces are formed such that thrust forces along the axial direction L act in opposite directions to each other.

[0045] In this embodiment, the power generation device 100 further includes an internal combustion engine 8 in addition to the above-described rotating electric machine 5. The internal combustion engine 8 is a prime mover (such as a gasoline engine or a diesel engine) that is driven by the combustion of fuel to extract power. The internal combustion engine 8 includes a cylinder 81, a piston 82, and a connecting rod 83. In this embodiment, the internal combustion engine 8 further includes a crankcase 84.

[0046] The cylinder 81 is a member formed in a cylindrical shape. In this embodiment, the cylinder 81 is formed to extend along the input direction I.

[0047] The piston 82 is configured to reciprocate within the cylinder 81. In this embodiment, the piston 82 is configured to reciprocate along the input direction I.

[0048] The connecting rod 83 is connected to the piston 82. The connecting rod 83 is connected to the crank member 2 so as to be relatively rotatable via the input member 3. In this embodiment, the connecting rod 83 is formed to extend along the input direction I.

[0049] The crankcase 84 houses the connecting rod 83 and the power conversion device 10. The crankcase 84 is integrally formed with the cylinder 81.

[0050] In this embodiment, the internal combustion engine 8 is disposed outside the stator 51 in the radial direction R and at a position overlapping the stator 51 in a radial view along the radial direction R. In the example shown in FIG. 4, the connecting portion of the cylinder 81, piston 82, and connecting rod 83 of the internal combustion engine 8 with the piston 82 is disposed so as to overlap the stator 51 in a radial view along the radial direction R.

[0051] In this embodiment, the power conversion device 10 includes a pair of crank members 2 and a pair of input members 3.

[0052] The pair of crank members 2 are disposed on both sides in the axial direction L with respect to the planetary gear PG. In this embodiment, one crank member 2 is disposed on the first axial side L1 with respect to the first planetary gear PG1. And the other crank member 2 is disposed on the second axial side L2 with respect to the second planetary gear PG2.

[0053] The pair of input members 3 are respectively supported by the pair of crank members 2. In this embodiment, one input member 3 is fixed to one crank member 2 so as to protrude from the one crank member 2 in the first axial direction L1. And the other input member 3 is fixed to the other crank member 2 so as to protrude from the other crank member 2 in the second axial direction L2. Also, in this embodiment, the pair of input members 3 are disposed such that their positions in the input direction I are the same as each other.

[0054] In this embodiment, the internal combustion engine 8 includes a pair of connecting rods 83. The pair of connecting rods 83 are connected so as to move integrally with the piston 82. The pair of connecting rods 83 are respectively connected to the pair of crank members 2 via the pair of input members 3. That is, one connecting rod 83 is connected to one crank member 2 via one input member 3 so as to be relatively rotatable. And the other connecting rod 83 is connected to the other crank member 2 via the other input member 3 so as to be relatively rotatable.

[0055] In this embodiment, the carrier CR of the planetary gear mechanism 1 is connected via the rotor support member 7 so as to rotate integrally with the rotor 52 of the rotary electric machine 5. In this embodiment, the specific rotating member RT is the carrier CR. Therefore, in this embodiment, the rotor support member 7 connected to the carrier CR functions as the output member 4.

[0056] In this embodiment, the first planetary bearing B11 is disposed on the first axial side L1 with respect to the tooth portion of the first planetary gear PG1, and the second planetary bearing B12 is disposed on the second axial side L2 with respect to the tooth portion of the second planetary gear PG2. And the first carrier bearing B21 is disposed on the first axial side L1 with respect to the tooth portion of the first ring gear RG1, and the second carrier bearing B22 is disposed on the second axial side L2 with respect to the tooth portion of the second ring gear RG2. Further, the rotor support member 7 is disposed between the tooth portions of the first ring gear RG1 and the second ring gear RG2 in the axial direction L.

[0057] In this embodiment, along with the reciprocating motion of the piston 82 of the internal combustion engine 8, the driving force along the input direction I is transmitted to the pair of input members 3 via the pair of connecting rods 83. Then, the reciprocating motion along the input direction I of the pair of input members 3 is converted into the rotational motion of the output member 4 by the planetary gear mechanism 1. As a result, the rotary electric machine 5 generates electricity by the driving force transmitted to the rotor 52 via the rotor support member 7 as the output member 4.

[0058] 5. Fifth Embodiment Hereinafter, the power conversion device 10 according to the fifth embodiment and the power generation device 100 including the same will be described with reference to FIG. 5. In the power conversion device 10 according to this embodiment, mainly the configuration of the planetary gear mechanism 1 is different from that of the fourth embodiment described above. Hereinafter, the description will focus on the differences from the fourth embodiment. Note that matters not particularly described are the same as those in the fourth embodiment.

[0059] As shown in FIG. 5, in the present embodiment, the planetary gear mechanism 1 does not include a plurality of planetary gears and a plurality of ring gears, but includes one planetary gear PG and one ring gear RG.

[0060] In the present embodiment, the first planetary bearing B11 is arranged on the first axial side L1 with respect to the tooth portion (planetary gear tooth portion PGa) of the planetary gear PG, and the second planetary bearing B12 is arranged on the second axial side L2 with respect to the tooth portion (planetary gear tooth portion PGa) of the planetary gear PG. And the first carrier bearing B21 is arranged on the first axial side L1 with respect to the tooth portion of the ring gear RG, and the second carrier bearing B22 is arranged on the second axial side L2 with respect to the tooth portion of the ring gear RG. Further, the rotor support member 7 is arranged between the tooth portion of the ring gear RG and the second carrier bearing B22 in the axial direction L.

[0061] 6. Other Embodiments (1) In the above embodiment, the configuration in which the radius r2 of the planetary gear PG is the same as the distance d in the planetary radial direction Rp between the planetary axis X2 and the input axis X3 has been described as an example. However, the present invention is not limited to such a configuration, and the radius r2 of the planetary gear PG and the distance d in the planetary radial direction Rp between the planetary axis X2 and the input axis X3 may be different from each other. In this configuration, the movement locus in the reciprocating movement of the input member 3 is elliptical with the carrier axis X1 as the center in the axial direction view along the axial direction L.

[0062] (2) In the above embodiment, the configuration in which the input member 3 is a shaft member fixed to the crank member 2 has been described as an example. However, the present invention is not limited to such a configuration, and for example, a configuration may be adopted in which a shaft member as the input member 3 is not provided and a part of the crank member 2 functions as the input member 3.

[0063] (3) In the above fourth and fifth embodiments, the configuration in which the power generation device 100 includes the internal combustion engine 8 has been described as an example. However, the present invention is not limited to such a configuration, and for example, the power generation device 100 may be configured to include a piston-type pump instead of the internal combustion engine 8.

[0064] (4) In addition, the configurations disclosed in the above-described embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs. Regarding other configurations as well, all the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope not departing from the gist of the present disclosure.

[0065] 7. Summary of this embodiment Hereinafter, an overview of the power conversion device (10) and the power generation device (100) described above will be described.

[0066] The power conversion device (10) includes a planetary gear mechanism (1) including a ring gear (RG) which is a fixed internal gear, a planetary gear (PG) meshing with the ring gear (RG), and a carrier (CR) rotatably supporting the planetary gear (PG), a crank member (2) arranged to extend in a planetary radial direction (Rp) orthogonal to a planetary axis (X2) which is a rotation axis of the planetary gear (PG) and connected so as to rotate integrally with the planetary gear (PG), an input member (3) supported by the crank member (2) and arranged on an input axis (X3) spaced apart from the planetary axis (X2) in the planetary radial direction (Rp), an output member (4) connected to a specific rotating member (RT) rotating in conjunction with the carrier (CR) excluding the planetary gear (PG), and a radius (r1) of the ring gear (RG) is twice a radius (r2) of the planetary gear (PG), with a direction along a carrier axis (X1) which is a rotation axis of the carrier (CR) as an axial direction (L) and a direction orthogonal to the carrier axis (X1) as a radial direction (R), a first planetary bearing (B11) and a second planetary bearing (B12) rotatably supporting the planetary gear (PG) with respect to the carrier (CR) are arranged separately on both sides of the tooth portion (PGa) of the planetary gear (PG) in the axial direction (L), A first carrier bearing (B21) and a second carrier bearing (B22) that rotatably support the carrier (CR) with respect to the ring gear (RG) are arranged separately on both sides of the tooth portion (RGa) of the ring gear (RG) in the axial direction (L). The first carrier bearing (B21) is arranged so as to overlap with the movement locus of the first planetary bearing (B11) accompanying the revolution of the planetary gear (PG) in a radial view along the radial direction (R). The second carrier bearing (B22) is arranged so as to overlap with the movement locus of the second planetary bearing (B12) accompanying the revolution of the planetary gear (PG) in the radial view.

[0067] According to this configuration, the first planetary bearing (B11) and the second planetary bearing (B12) arranged separately on both sides of the tooth portion (PGa) of the planetary gear (PG) in the axial direction (L) rotatably support the planetary gear (PG) with respect to the carrier (CR). Further, the first carrier bearing (B21) and the second carrier bearing (B22) arranged separately on both sides of the tooth portion (RGa) of the ring gear (RG) in the axial direction (L) rotatably support the carrier (CR) with respect to the ring gear (RG). Thereby, it is easy to secure the support rigidity of the planetary gear (PG). Therefore, even when an axially-biased load acts on the planetary gear (PG), the load can be appropriately supported. Also, according to this configuration, the first carrier bearing (B21) overlaps with the movement locus of the first planetary bearing (B11) accompanying the revolution of the planetary gear (PG) in a radial view, and the second carrier bearing (B22) overlaps with the movement locus of the second planetary bearing (B12) accompanying the revolution of the planetary gear (PG) in a radial view. Therefore, it is easy to keep the axial dimension (L) of the power conversion device (10) small.

[0068] Here, the ring gear (RG) includes a first support portion (12) and a second support portion (13) extending on both sides of the tooth portion (RGa) of the ring gear (RG) in the axial direction (L). The first support portion (12) supports the first carrier bearing (B21) from the outside in the radial direction (R), and is arranged so as to overlap with the movement locus of the first planetary bearing (B11) accompanying the revolution of the planetary gear (PG) in the radial view. It is preferable that the second support portion (13) supports the second carrier bearing (B22) from the outside in the radial direction (R), and is arranged so as to overlap with the movement locus of the second planetary bearing (B12) accompanying the revolution of the planetary gear (PG) in the radial view.

[0069] According to this configuration, the first support portion (12) and the second support portion (13) extending to both sides in the axial direction (L) with respect to the tooth portion (RGa) of the ring gear (RG) can appropriately support the carrier (CR) with respect to the ring gear (RG) via the first carrier bearing (B21) and the second carrier bearing (B22). Further, the planetary gear (PG) can be appropriately supported with respect to the carrier (CR) via the first planetary bearing (B11) and the second planetary bearing (B12). Thereby, the support rigidity of the planetary gear (PG) can be greatly ensured.

[0070] It is preferable that the radius (r2) of the planetary gear (PG) is the same as the distance (d) in the planetary radial direction (Rp) between the planetary axis (X2) and the input axis (X3).

[0071] According to this configuration, the movement locus in the reciprocating motion of the input member (3) can be made linear. Therefore, the operation of the power conversion device (10) can be easily simplified.

[0072] Further, the planetary gear mechanism (1) a small-diameter planetary gear (PGS) having a radius smaller than that of the large-diameter planetary gear (PGL) as the planetary gear (PG) and rotating integrally with the large-diameter planetary gear (PGL), and a sun gear (SG) disposed on the carrier axis (X1) and meshing with the small-diameter planetary gear (PGS). It is preferable that the output member (4) is connected so as to rotate integrally with the sun gear (SG).

[0073] According to this configuration, the rotation of the carrier (CR) can be speed-changed and transmitted to the output member (4). Further, such speed change can be realized with a simple configuration.

[0074] Further, the ring gear (RG) includes a first ring gear (RG1) and a second ring gear (RG2) that are arranged at different positions in the axial direction (L) from each other. The planetary gear (PG) includes a first planetary gear (PG1) that meshes with the first ring gear (RG1) and a second planetary gear (PG2) that meshes with the second ring gear (RG2). The first planetary gear (PG1) and the second planetary gear (PG2) are preferably helical gears in which tooth surfaces are formed such that thrust forces along the axial direction (L) act in opposite directions to each other.

[0075] According to this configuration, compared with a configuration in which the first planetary gear (PG1) and the second planetary gear (PG2) are spur gears, the tooth surface strength of the first planetary gear (PG1) and the second planetary gear (PG2), and the quietness of the meshing portion between the first planetary gear (PG1) and the first ring gear (RG1) and the meshing portion between the second planetary gear (PG2) and the second ring gear (RG2) can be enhanced. Further, according to this configuration, it is easy to simplify the support structure of the thrust forces acting on the first planetary gear (PG1) and the second planetary gear (PG2).

[0076] The power generation device is the above-described power conversion device (10), an internal combustion engine (8) including a cylinder (81), a piston (82) that reciprocates in the cylinder (81), and a connecting rod (83) connected to the piston (82), and a power generation device (100) including a rotating electrical machine (5) having a stator (51) and a rotor (52), wherein the crank member (2) and the connecting rod (83) are connected to each other via the input member (3) so as to be relatively rotatable. The output member (4) and the rotor (52) are connected to each other so as to rotate integrally. The power conversion device (10) is disposed inside the stator (51) in the radial direction (R) and at a position overlapping the stator (51) in a view in the radial direction.

[0077] According to this configuration, a power generation device (100) that functions as a generator using the rotation of the rotating electrical machine (5) and generates electricity using the driving force of the internal combustion engine (8) can be configured to be small.

[0078] Here, the power conversion device (10) includes a pair of the crank members (2) separately disposed on both sides of the planetary gear (PG) in the axial direction (L), and a pair of the input members (3) respectively supported by the pair of the crank members (2). It is preferable that the internal combustion engine (8) includes a pair of the connecting rods (83) respectively connected to the pair of the crank members (2) via the pair of the input members (3).

[0079] According to this configuration, loads are input from the connecting rods (83) to the crank members (2) disposed on one side and the other side of the planetary gear (PG) in the axial direction (L) via the input members (3). Therefore, it is possible to reduce the uneven load acting on the planetary gear (PG) connected to the pair of the crank members (2).

Industrial Applicability

[0080] The technology according to the present disclosure can be used for a power conversion device that converts a reciprocating motion into a rotational motion and a power generation device including the same.

Description of Reference Numerals

[0081] 10: Power conversion device, 100: Power generation device, 1: Planetary gear mechanism, 12: First support portion, 13: Second support portion, 2: Crank member, 3: Input member, 4: Output member, 5: Rotating electric machine, 51: Stator, 52: Rotor, 8: Internal combustion engine, 81: Cylinder, 82: Piston, 83: Connecting rod, RG: Ring gear, RGa: Ring gear tooth portion, RG1: First ring gear, RG2: Second ring gear, PG: Planetary gear, PGa: Planetary gear tooth portion, PGL: Large-diameter planetary gear, PGS: Small-diameter planetary gear, PG1: First planetary gear, PG2: Second planetary gear, CR: Carrier, SG: Sun gear, RT: Specific rotating member, B11: First planetary bearing, B12: First planetary bearing, B21: First carrier bearing, B22: Second carrier bearing, X1: Carrier axis center, X2: Planetary axis center, X3: Input axis center, L: Axial direction, R: Radial direction, Rp: Planetary radial direction

Claims

1. A planetary gear mechanism including a ring gear which is a fixed internal gear, a planetary gear meshing with the ring gear, and a carrier rotatably supporting the planetary gear, a crank member disposed so as to extend in a planetary radial direction orthogonal to the planetary axis which is the rotation axis of the planetary gear, and connected so as to rotate integrally with the planetary gear, an input member supported by the crank member and disposed on an input axis spaced from the planetary axis in the planetary radial direction, and an output member connected to a specific rotating member that rotates in conjunction with the carrier excluding the planetary gear, wherein the radius of the ring gear is twice the radius of the planetary gear, with the direction along the carrier axis which is the rotation axis of the carrier as the axial direction and the direction orthogonal to the carrier axis as the radial direction, a first planetary bearing and a second planetary bearing for rotatably supporting the planetary gear with respect to the carrier are disposed separately on both sides in the axial direction with respect to the tooth portion of the planetary gear, a first carrier bearing and a second carrier bearing for rotatably supporting the carrier with respect to the ring gear are disposed separately on both sides in the axial direction with respect to the tooth portion of the ring gear, the first carrier bearing is disposed so as to overlap the movement locus of the first planetary bearing accompanying the revolution of the planetary gear in a radial view along the radial direction, and the second carrier bearing is disposed so as to overlap the movement locus of the second planetary bearing accompanying the revolution of the planetary gear in the radial view, a power conversion device.

2. The ring gear includes a first support portion and a second support portion extending on both sides in the axial direction with respect to the tooth portion of the ring gear, the first support portion supports the first carrier bearing from the outside in the radial direction and is disposed so as to overlap the movement locus of the first planetary bearing accompanying the revolution of the planetary gear in the radial view, and the second support portion supports the second carrier bearing from the outside in the radial direction and is disposed so as to overlap the movement locus of the second planetary bearing accompanying the revolution of the planetary gear in the radial view, the power conversion device according to claim 1.

3. The power conversion device according to claim 1 or 2, wherein the radius of the planetary gear is the same as the distance in the planetary radial direction between the planetary axis and the input axis.

4. The planetary gear mechanism includes a small-diameter planetary gear having a radius smaller than that of a large-diameter planetary gear serving as the planetary gear and rotating integrally with the large-diameter planetary gear, Further provided with a sun gear disposed on the carrier axis and meshing with the small-diameter planetary gear. The power conversion device according to claim 1 or 2, wherein the output member is connected so as to rotate integrally with the sun gear.

5. The ring gear includes a first ring gear and a second ring gear disposed at different positions in the axial direction from each other. The planetary gear includes a first planetary gear meshing with the first ring gear and a second planetary gear meshing with the second ring gear. The power conversion device according to claim 1 or 2, wherein the first planetary gear and the second planetary gear are helical gears having tooth surfaces formed such that thrust forces acting along the axial direction are opposite to each other.

6. A power conversion device according to claim 1 or 2, An internal combustion engine including a cylinder, a piston reciprocating in the cylinder, and a connecting rod connected to the piston, A power generation device including a rotating electrical machine having a stator and a rotor, wherein The crank member and the connecting rod are connected to each other via the input member so as to be relatively rotatable. The output member and the rotor are connected to each other so as to rotate integrally. The power generation device, wherein the power conversion device is disposed inside the stator in the radial direction and at a position overlapping the stator in a radial view.

7. The power conversion device includes a pair of crank members divided and disposed on both sides of the planetary gear in the axial direction, and a pair of input members respectively supported by the pair of crank members. The power generation device according to claim 6, wherein the internal combustion engine includes a pair of connecting rods connected to the pair of crank members via the pair of input members respectively.

Images