Planetary gear transmission

Abstract

To provide a compact planetary gear transmission device comprising an oil pump.SOLUTION: In a compact planetary gear transmission device 10, a ring gear 23 is fixed to a casing 30 so as to be incapable of relatively rotating, and a planetary carrier 25 pivotally supporting a planetary gear 22 is supported by the casing 30 so as to be capable of relatively rotating around a sun gear 21. An oil pump 50 for pumping oil serving as lubricating oil into the casing 30 is arranged at a position offset with respect to the sun gear 21. The planetary carrier 25 is provided with a pump drive gear 60 functioning as a transmission part for driving the oil pump 50.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a planetary gear transmission. [Background technology]

[0002] A planetary gear transmission device is known that includes a sun gear housed within a casing, a plurality of planetary gears that mesh with the sun gear on the outer periphery of the sun gear, and a ring gear that meshes with the planetary gears on the outer periphery of the planetary gears. An oil pump is required to supply oil to various parts of this type of planetary gear transmission device for lubrication, but since this document does not mention an oil pump within the planetary gear transmission device, it is thought that oil is usually introduced into the planetary gear transmission device from an oil pump provided outside the planetary gear transmission device (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-220495 Summary of the Invention [Problem to be solved by the invention]

[0004] However, a configuration in which oil is introduced from an external oil pump results in an increase in size and complexity of the overall configuration including the oil pump, lubrication structure, and planetary gear transmission device. The present invention has been made in view of the above background, and has an object to provide a small-sized planetary gear transmission device equipped with an oil pump. [Means for solving the problem]

[0005] In a planetary gear transmission device provided with a sun gear housed within a casing, a plurality of planetary gears meshing with the sun gear on the outer periphery of the sun gear, and a ring gear meshing with the planetary gear on the outer periphery of the planetary gear, the ring gear is fixed to the casing so as not to rotate relative to the sun gear, a planetary carrier supporting the planetary gears is supported on the casing so as to rotate relative to the sun gear, an oil pump for pumping oil as lubricating oil into the casing is disposed at a position offset from the sun gear, and a transmission unit for driving the oil pump is provided on the planetary carrier. The rotation axis of the planetary gear transmission device is oriented along the vertical direction, the casing has a divided structure including a first casing in a lower stage, a second casing in a middle stage, and a third casing in an upper stage, the first casing and the second casing rotatably support a pump shaft of the oil pump, the upper surface of the first casing is provided with a first oil discharge port and a second oil discharge port which are provided at mutually different positions by a plurality of grooves and serve as discharge ports of the oil pump, the oil from the first oil discharge port is supplied to the planetary carrier via an oil passage formed across the first casing, the second casing, and the third casing, and the oil from the second oil discharge port is supplied to the sun gear via another oil passage formed in the first casing and the second casing. A planetary gear transmission is provided. [Effects of the Invention]

[0006] A compact planetary gear transmission device equipped with an oil pump can be provided. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing an aircraft equipped with a planetary gear transmission device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the planetary gear transmission device together with the surrounding configuration. [Figure 3] FIG. 2 is an exploded perspective view showing a part of the planetary gear mechanism together with the surrounding configuration. [Figure 4] FIG. 2 is an exploded perspective view of the oil pump. [Figure 5] FIG. 2 is a perspective view showing the second casing and the first casing from diagonally above. [Figure 6] FIG. 4 is a perspective view showing the second casing from diagonally below. [Figure 7] FIG. 4 is a diagram showing the flow of oil in the first casing. [Figure 8] FIG. 4 is a cross-sectional view showing the flow of oil in a gear device. [Figure 9] FIG. 9 is a cross-sectional view showing a different oil flow in the gear device from that in FIG. 8. [Figure 10] FIG. 10 is a cross-sectional view showing the oil flow in the gear device, which is different from that in FIGS. 8 and 9. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] [Embodiment] FIG. 1 is a diagram showing an aircraft 1 equipped with a planetary gear transmission device 10 according to an embodiment of the present invention. The aircraft 1 is a vertical take-off and landing aircraft such as a VTOL (Vertical Take-Off and Landing) aircraft, and is equipped with a rotor 2 for vertical take-off and landing and a rotor 3 for propulsion. Each of the rotors 2, 3 is driven by a motor. The aircraft 1 is equipped with a battery that stores electricity to be supplied to a plurality of motors that individually drive each of the rotors 2, 3, and a control unit that controls the motors. The number and positions of the rotors 2, 3 of the aircraft 1 may be changed as appropriate. The aircraft 1 may also be a hybrid aircraft equipped with a generator that generates electricity using a gas turbine or the like, or may be either a manned or unmanned flying vehicle. The rotors 2, 3 may also be driven by a source other than a motor.

[0010] FIG. 2 is a cross-sectional view of the planetary gear transmission device 10 together with the surrounding configuration. The planetary gear transmission device 10 is disposed between the rotor 2 for vertical take-off and the motor 2M for driving the rotor, and is a device that reduces the rotation of the motor 2M and transmits it to the rotor 2, and can also be called a gear device, power transmission device, speed change device, etc. for the rotor. In the following description, the planetary gear transmission device 10 will be referred to as the "gear device 10."

[0011] In Figure 2, the symbol UP indicates the upward direction when this gear device 10 is mounted on the aircraft 1. A motor 2M is disposed below this gear device 10, and a rotor 2 is disposed above the gear device 10. Directions in this description refer to directions when the device is mounted on the aircraft 1, unless otherwise specified.

[0012] The gear device 10 comprises an input shaft 11 to which the rotation of the motor 2M is transmitted, an output shaft 12 that rotates the rotor 2, a planetary gear mechanism 20 that reduces the rotation of the input shaft 11 and transmits it to the output shaft 12, and a casing 30 that houses these. The input shaft 11 and the output shaft 12 are arranged on the same axis C1. This axis C1 corresponds to an axis (central axis) that passes through the centers of the planetary gear mechanism 20 and the gear device 10, and is also an axis that extends in the up-down direction (vertical axis). Hereinafter, the casing 30 will be referred to as the "gear casing 30," and the axis C1 will be referred to as the "central axis C1."

[0013] As shown in Figure 2, a casing 41 on the motor 2M side is fixed to the underside of the gear casing 30 by fastening members 40. This casing 41 is a motor casing that is the case of the motor 2M, and the input shaft 11 is driven to rotate by the motor 2M. In other words, the motor 2M is connected to the gear casing 30 so as to be integral with it. Note that the casing 41 does not have to be a motor casing, and may be, for example, another casing located between the motor casing and the gear casing 30. The gear casing 30 is formed in an upper and lower divided structure consisting of a first casing 31 constituting the lower casing located at the bottom, a second casing 32 constituting the intermediate casing located in the middle between the top and bottom, and a third casing 33 constituting the upper casing located at the top.

[0014] The input shaft 11 passes through a through-hole 31C provided in the center of the first casing 31 (at a position corresponding to the central axis C1) and enters the first casing 31. The planetary gear mechanism 20 includes a sun gear 21 that rotates integrally with the input shaft 11, a plurality of planetary gears 22 that mesh with the sun gear 21 on the outer periphery of the sun gear 21, and a ring gear 23 that meshes with the planetary gears 22 on the outer periphery of the planetary gears 22.

[0015] FIG. 3 is an exploded perspective view showing a part of the planetary gear mechanism 20 together with the surrounding configuration. As shown in Fig. 2, sun gear 21 is fitted onto the outer periphery of input shaft 11. Furthermore, referring also to Fig. 3, planetary gears 22 are provided around sun gear 21 at predetermined angular intervals and are supported by planetary carrier 25 so as to be rotatable (spin on their axes). The planetary carrier 25 of this configuration includes a planetary carrier main body 25A located above the planetary gear 22, and a base portion 25B located below the planetary gear 22 on the opposite side.

[0016] The planetary carrier main body 25A integrally includes the output shaft 12 and a flange 25AF having a diameter larger than that of the output shaft 12. The base plate 25B is formed in a disk shape having a cylindrical portion 25BT integrally therewith that protrudes downward, and has a plurality of holes 25BH into which the same number of cylindrical bodies 26 as the planetary gears 22 are fitted at equal angular intervals. As shown in FIG. 2, each cylindrical body 26 is held between a flange portion 25AF of the planetary carrier main body 25A and a base portion 25B. The planetary gear 22 is rotatably supported on the outer periphery of each cylindrical body 26 via a bearing 22J. This allows the planetary gear 22 to be rotatably provided between the planetary carrier main body 25A and the base portion 25B. Although the number of planetary gears 22 in this embodiment is three, the number is not limited to three. The shape of the planetary carrier 25 may be changed as appropriate.

[0017] The ring gear 23 has a row of teeth on its inner circumference and meshes with each planetary gear 22 (see FIG. 3). The ring gear 23 is fixed to the third casing 33 so as not to rotate. The planetary carrier main body 25A is rotatably supported by the third casing 33 via an upper bearing 42U. The base plate 25B is rotatably supported by the second casing 32 via a lower bearing 42L. The planetary carrier main body 25A and the base plate 25B rotate integrally.

[0018] Regarding the support structure for the upper bearing 42U, a cylindrical bearing housing 35 for supporting the bearing is attached from below within the third casing 33. The upper bearing 42U is inserted between the outer peripheral surface of this bearing housing 35 and an upwardly extending cylindrical portion 25AW that extends upward from the outermost peripheral portion of the flange portion 25AF of the planetary carrier main body 25A. According to this support structure for the shaft 42U, the bearing 42U is disposed so as to be housed on the inner peripheral side of the flange portion 25AF, so that the bearing 42U does not protrude outward from the outer peripheral side of the flange portion 25AF, and the third casing 33 can be easily made smaller without expanding in the radial direction.

[0019] Regarding the support structure for the lower bearing 42L, the inner peripheral surface of the lower bearing 42L is fitted into the cylindrical portion 25BT of the base portion 25B, and the second casing 32 is provided with an outer peripheral cylindrical portion 32BT (see FIG. 5) into which the outer peripheral surface of the lower bearing 42L is fitted. The cylindrical portion 25BT (see FIG. 2) of the base portion 25B extends toward the motor 2M and is located inner than the outermost peripheral portion (corresponding to the upwardly extending cylindrical portion 25AW) of the planetary carrier main body 25A, and the lower bearing 42L has a smaller diameter than the upper bearing 42U. This ensures space for the oil pump 50, which will be described later, radially outward from the bearing 42L. The sizes of the bearings 42L and 42U may be set appropriately according to the specifications.

[0020] Incidentally, it is desirable that each part of the gear device 10 be lubricated with lubricating oil. In this configuration, an oil pump 50 that supplies oil as lubricating oil is provided inside the gear casing 30. As shown in FIG. 2, the oil pump 50 is positioned radially outward of the lower bearing 42U, and is therefore positioned at a radially offset position relative to the sun gear 21, and the oil pump 50 can be easily rotated by a pump drive gear 60 provided on the planetary carrier 25.

[0021] The oil pump 50 and its surrounding structure will now be described in detail. As shown in Fig. 3, pump drive gear 60 is formed in a ring shape with a row of teeth on its outer periphery, and is fixed to base portion 25B from below with a plurality of fastening members 61 (Fig. 2). As shown in Fig. 2, the central axis of pump drive gear 60 coincides with central axis C1 of planetary gear mechanism 20, and pump drive gear 60 is positioned within a range that does not exceed the outer diameter of base portion 25B.

[0022] In this configuration, the pump drive gear 60 is disposed in the space around the sun gear 21 and below the base plate portion 25B. More specifically, the pump drive gear 60 is disposed between the base plate portion 25B and the lower bearing 42L, radially outward of the cylindrical portion 25BT of the base plate portion 25B. Therefore, by disposing the pump drive gear 60, it is possible to prevent the gear casing 30 from becoming larger in the axial and radial directions, and it is also possible to prevent the gear device 10 from becoming larger. The lower bearing 42L corresponds to the "first bearing member" of the present invention, and the upper bearing 42U corresponds to the "second bearing member" or "other bearing member" of the present invention.

[0023] FIG. 4 is an exploded perspective view of the oil pump 50. As shown in FIG. The oil pump 50 includes a pump shaft 51, a pump driven gear 52 fixed to the upper part of the pump shaft 51, and a pumping unit 53 provided at the lower part of the pump shaft 51 and generating pressure to pump the oil. This oil pump 50 is of a trochoid type. That is, the pumping unit 53 includes an inner rotor 53A fixed to the pump shaft 51 and an outer rotor 53B surrounding the inner rotor 53A. The outer rotor 53B is disposed within the gear casing 30 so as to be rotatable about an axis that is eccentric from the pump shaft 51. The inner rotor 53A rotates about an axis that is eccentric in the radial direction relative to the outer rotor 53B. As a result, the cell chamber defined between inner rotor 53A and outer rotor 53B is sequentially connected to oil suction port 71 (FIG. 5) and oil discharge port 72 (FIG. 5), and the volume of the cell chamber is reduced as it connects from oil suction port 71 to oil discharge port 72, so that the oil introduced into the cell chamber is pressurized and supplied to oil discharge port 72. The shape and structure of oil pump 50 including pressure-feeding section 53 do not have to be limited to those shown in FIG.

[0024] In this configuration, the pump shaft 51 of the oil pump 50 is rotatably supported by the second casing 32 and the first casing 31 . Fig. 5 is a perspective view showing the second casing 32 and the first casing 31 from diagonally above. Fig. 6 is a perspective view showing the second casing 32 from diagonally below. 5 and 6, the second casing 32 is provided with a support portion 32S that supports an upper portion of the pump shaft 51 at a position radially offset from the cylindrical portion 32T through which the input shaft 11 passes. As shown in Fig. 5, the first casing 31 is provided with a support portion 31S that supports a lower portion of the pump shaft 51 at a position opposite to the support portion 32S of the second casing 32, in other words, at a position radially offset from the through hole 31C through which the input shaft 11 passes.

[0025] The pump shaft 51 is supported by a pair of upper and lower shaft supports 32S, 31S via a pair of upper and lower flange bushings 54 (Fig. 4), and then the pump driven gear 52 and a lock nut 55 (Fig. 4) are attached in this order from above. As a result, the oil pump 50 is supported by the gear casing 30 with the pump shaft 51 oriented vertically, as shown in Fig. 2. 2, in the radial direction (corresponding to the left-right direction or width direction), the oil pump 50 is located radially outward of the sun gear 21 and the lower bearing 42L, and is located radially inward of the outermost periphery of the ring gear 23. In addition, the oil pump 50 is located axially below the planetary carrier 25, the upper bearing 42U, the sun gear 21, and the ring gear 23, and above the first casing 31.

[0026] Therefore, the oil pump 50 is disposed in a region overlapping the lower bearing 42L and the base portion 25B (portion of the cylindrical portion 25BT) of the planetary carrier 25 when viewed in the radial direction, and is disposed in a region overlapping the outermost peripheral position of the planetary carrier 25 when viewed in the axial direction. This allows the oil pump 50, bearing 42L, and base portion 25B of the planetary carrier 25 to be disposed close to one another in a compact manner.

[0027] Next, the configuration relating to lubrication inside the gear casing 30 will be described. 5, the second casing 32 integrally includes a cylindrical outer peripheral wall 32W extending in the vertical direction, a cylindrical portion 32T through which the input shaft 11 passes, and a flange portion 32F whose diameter increases from the cylindrical portion 32T. Fastening through holes 32H are formed at intervals in the circumferential direction in the outermost peripheral portion of the outer peripheral wall 32W. Fastening members (e.g., bolts) for fastening and fixing the second casing 32 to the first casing 31 and the third casing 33 are passed through these fastening through holes 32H. The flange portion 32F is formed in a concave shape that is recessed downward and into which the outer peripheral surface of the lower bearing 42L fits, thereby functioning as a bearing housing that supports the lower bearing 42L.

[0028] Between the outer peripheral wall 32W and the flange portion 32F, a bearing portion 32S that supports the upper portion of the pump shaft 51 is provided, and a recessed portion 32K that is recessed in an annular shape excluding the bearing portion 32S is provided. Through holes 32KH are provided in the recessed portion 32K at intervals in the circumferential direction. These through holes 32KH function as oil passage holes that allow oil from above to drop downward (into the first casing 31).

[0029] 6, oil passages 32X that penetrate the outer peripheral wall 32W in the up-down direction are provided in the outer peripheral wall 32W of the second casing 32. These oil passages 32X communicate with an oil discharge passage 74A (FIG. 5) provided in the first casing 31. Furthermore, oil passages 32Y that communicate with an oil discharge passage 74C (FIG. 5) provided in the first casing 31 are provided in the cylindrical portion 32T of the second casing 32 at intervals in the circumferential direction.

[0030] Fig. 7 is a diagram showing the flow of oil in the first casing 31. The arrows in Fig. 7 indicate the direction of oil flow. 6 and 7, the first casing 31 is formed in a disk shape with a flat upper surface, has a through hole 31C in the center of the first casing 31 through which the input shaft 11 passes, and has fastening through holes 31H spaced apart in the circumferential direction at the outermost periphery of the first casing 31. The fastening through holes 31H communicate with fastening through holes 32H of the second casing 32. A bearing portion 31S that supports the lower part of the pump shaft 51 is provided on the upper surface of the first casing 31. Furthermore, a plurality of grooves are formed on the upper surface of the first casing 31, and these grooves form an oil suction port 71, an oil discharge port 72, an oil suction passage 73 connected to the oil suction port 71, and an oil discharge passage 74 connected to the oil discharge port 72.

[0031] The oil suction port 71 is provided on one circumferential side of the bearing portion 31S relative to the central axis C1. The oil suction passage 73 is formed as a groove extending in an annular shape centered on the central axis C1, and one end of the oil suction passage 73 is connected to the oil suction port 71. The oil suction passage 73 is positioned so as to overlap in the vertical direction with the through-hole 32KH provided in the second casing 32, and oil that drops downward from the through-hole 32KH flows into the oil suction passage 73. The oil discharge port 72 is provided on the opposite side of the journal support portion 31S from the oil suction port 71, in other words, on the other circumferential side of the journal support portion 31S with respect to the central axis C1. The radially outer end of this oil discharge port 72 functions as a first oil discharge port 72A that discharges oil toward the outer periphery of the casing. Furthermore, the radially inner end of this oil discharge port 72 functions as a second oil discharge port 72B that discharges oil toward the inner periphery of the casing.

[0032] As shown in Figure 7, oil discharged from the first oil discharge port 72A is supplied to the oil passage 32X (Figures 5 and 6) provided in the second casing 32 via the oil discharge passage 74A extending radially outward from the first oil discharge port 72. 8, 9 and 10 are cross-sectional views showing the flow of oil within the gear device 10. FIG.

[0033] As shown in FIG. 8, the third casing 33 is provided with an oil passage 33X that connects to the oil passage 32X provided in the second casing 32. This oil passage 33X supplies oil from the first oil discharge port 72A through the third casing 33 toward the upper bearing 42U and the planetary carrier 25, as shown by the arrows in FIG. 8, thereby lubricating the upper bearing 42U and its surroundings. This oil falls downward due to gravity, accumulates in the gear casing 30, and is again sucked into the oil pump 50 through the oil suction port 71. Note that reference symbols L1 and L2 in FIGS. 8 to 10 are examples of oil reservoir lines for oil accumulated in the gear casing 30.

[0034] As shown in Figure 7, the oil discharged from the second oil discharge port 72B is supplied to an annular oil discharge passage 74C provided around the through hole 31C via an oil discharge passage 74B extending radially inward from the second oil discharge port 72B. The annular oil discharge passage 74C communicates with a plurality of oil passages 32Y (FIGS. 6 and 9) provided in the cylindrical portion 25BT of the second casing 32. The plurality of oil passages 32Y are oil passages that communicate with different oil passages 25Y1 (FIG. 9) and oil passages 25Y2 (FIG. 10) provided in the planetary carrier 25, respectively.

[0035] As shown in Fig. 9, the first oil passage 25Y1 is formed as an oil passage that supplies oil supplied from below to the sun gear 21. In addition, as shown in Fig. 10, the second oil passage 25Y2 is formed as an oil passage that supplies oil supplied from below to the bearing 22J of the planetary gear 22. As shown in Figure 9, the oil supplied to the sun gear 21 from the first oil passage 25Y1 lubricates the meshing parts between the sun gear 21 and the planetary gear 22, etc., and then falls due to gravity, is stored in the gear casing 30, and is again sucked into the oil pump 50 through the oil intake port 71.

[0036] 10, the oil supplied from the second oil passage 25Y2 to the bearing 22J lubricates the meshing portions of the planetary gear 22 and the ring gear 23, and then falls due to gravity, is stored in the gear casing 30, and is again sucked into the oil pump 50 through the oil suction port 71. In this way, multiple locations inside the gear casing 30 are appropriately lubricated.

[0037] As described above, in the gear device 10 of this embodiment, the ring gear 23 is fixed to the gear casing 30 so as not to rotate relative to the gear casing 30, the planetary carrier 25 that supports the planetary gears 22 is supported on the gear casing 30 so as to be rotatable relative to the sun gear 21, the oil pump 50 that pumps oil into the gear casing 30 is positioned offset from the sun gear 21, and the planetary carrier 25 is provided with a pump drive gear 60 that functions as a transmission unit that drives the oil pump 50.

[0038] According to this configuration, the oil pump 50 is disposed at a position offset from the sun gear 21, so that the oil pump 50 can be easily driven by a transmission unit provided on the planetary carrier 25, even while the oil pump 50 and the sun gear 21 are disposed on different axes. Also, by having the transmission unit drive only the oil pump 50, the axial thickness of the transmission unit (corresponding to the tooth thickness of the pump drive gear 60) can be reduced. As a result, it is possible to avoid disposing the oil pump 50 and the sun gear 21 on the same axis and to make it easier to shorten the transmission unit in the axial direction, thereby making it possible to reduce the axial size of the gear device 10 equipped with the oil pump 50.

[0039] Furthermore, the oil pump 50 is a trochoid type, and the transmission part is a pump drive gear 60 that meshes with a pump driven gear 52 provided on a pump shaft 51 of the oil pump 50. With this configuration, the trochoid type oil pump 50 can be driven with a simple transmission mechanism. This makes it possible to suppress an increase in the complexity of the structure and the number of parts, and makes it easier to make the gear device 10 more compact. The pump driven gear 52 corresponds to the "driven gear" of the present invention, and the pump drive gear 60 corresponds to the "drive gear" of the present invention.

[0040] Furthermore, the planetary carrier 25 has a base portion 25B on the opposite side of the planetary gear 22, and the pump drive gear 60 is fixed to the base portion 25B on the opposite side of the planetary gear 22. With this configuration, it is possible to design a layout that separates the power transmission path through the planetary gear 22 and the power transmission path to the oil pump 50 based on the base portion 25B, thereby preventing the power transmission mechanism from becoming too complicated and making it easier to make the gear device 10 more compact.

[0041] Additionally, the outer diameter of the pump drive gear 60 is set within a range not exceeding the outer diameter of the planetary carrier 25. This configuration makes it possible to adjust the outer diameter of the pump drive gear 60 within a range not exceeding the outer diameter of the planetary carrier 25 while suppressing an increase in the diameter of the gear device 10 due to the influence of the pump drive gear 60, which is advantageous for improving design freedom.

[0042] Also, the bearing 42L functions as a first bearing member that rotatably supports the base portion 25B, and the oil pump 50 is located radially outward of the bearing 42L. This configuration prevents the gear device 10 from becoming larger in the axial direction due to the oil pump 50 and the bearing 42L being aligned in the axial direction, and allows the space radially outward of the bearing 42L to be effectively used as the space for arranging the oil pump 50.

[0043] The oil pump 50 is disposed radially outward from the bearing 42L and radially inward from the outermost portion of the ring gear 23 relative to the sun gear 21, and is disposed at a position that overlaps with the outermost position of the planetary carrier 25 when viewed in the axial direction. As a result, the oil pump 50 is disposed in an area surrounded by the bearing 42L, planetary carrier 25, and ring gear 23, and overlaps with the outermost position of the planetary carrier 25 when viewed in the axial direction. With this configuration, the oil pump 50, bearing 42L, planetary carrier 25, and ring gear 23 can be disposed compactly, which is advantageous for reducing the overall size.

[0044] Furthermore, the gear casing 30 has a split structure including a first casing 31 integrated with the motor 2M serving as the drive source, and a second casing 32 connected to the first casing 31, and at least a portion of the oil passage (oil passages 32X, 33X) connected to the oil pump 50 is formed across the first casing 31 and the second casing 32. With this configuration, the oil passage can be formed using the gear casing 30, which has a split structure integrated with the motor 2M, which is advantageous for miniaturization, and it is also possible to separate the gear device 10 and the motor 2M without draining the oil, which is advantageous for improving maintainability.

[0045] Additionally, the pump shaft 51 of the oil pump 50 is rotatably supported by the first casing 31 and the second casing 32. With this configuration, the pump shaft 51 is supported using the gear casing 30 with a split structure, which makes it easier to make the support structure for the pump shaft 51 simple and compact, which is advantageous for reducing the size of the gear device 10.

[0046] Additionally, there are provided a plurality of oil discharge ports 72A, 72B that serve as discharge ports of the oil pump 50, and oil passages (oil discharge passages 74A, 74B, oil passages 32X, 33X, 25Y1, 25Y2) that are connected to each of the oil discharge ports 72A, 72B. This configuration makes it easy to supply oil with high discharge pressure from a single oil pump 50 to a plurality of locations, making it easy to properly lubricate many locations.

[0047] Furthermore, all of the rotational axes of the gear device 10 are oriented vertically, and the oil pump 50 is immersed in oil that accumulates in the lower part of the gear casing 30. This configuration makes it possible to provide a gear device 10 that is compact in the vertical direction while still including the oil pump 50, and also makes it easier to ensure a reliable, uninterrupted supply of oil. Furthermore, this gear device 10 constitutes a power transmission mechanism between the rotor 2 for vertical takeoff and landing and the motor 2M that serves as the driving source, thereby reducing the frontal projection area of ​​the aircraft 1's body and making it easier to reduce air resistance during flight.

[0048] The present invention is not limited to the configurations of the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the present invention. For example, while the present invention has been described with reference to a case in which the gear train 10 is used in the aircraft 1 shown in FIG. 1 , the present invention is not limited thereto and may be applied to gear trains used in other aircraft and moving bodies other than aircraft (vehicles, saddle-type vehicles, ships, etc.). Also, while the present invention has been described with reference to a case in which all of the rotational axes of the gear train 10 are oriented along the vertical direction, the orientation does not have to be limited to the vertical direction, and some of the rotational axes may be oriented along a different direction. Furthermore, the present invention has been described with reference to a case in which the transmission unit that drives the oil pump 50 is configured with a gear mechanism including the pump drive gear 60 and the pump driven gear 52, but the present invention is not limited to this configuration. For example, the transmission unit that drives the oil pump 50 may be configured with a power transmission mechanism other than a gear mechanism.

[0049] [Configuration supported by the above embodiment] The above embodiment supports the following configurations.

[0050] (Configuration 1) A planetary gear transmission device comprising a sun gear within a casing, a plurality of planetary gears meshing with the sun gear on the outer periphery of the sun gear, and a ring gear meshing with the planetary gear on the outer periphery of the planetary gear, wherein the ring gear is fixed to the casing so as not to rotate relative to it, a planetary carrier that supports the planetary gears is supported on the casing so as to be rotatable relative to it around the sun gear, an oil pump that pressurizes oil to serve as lubricant into the casing is positioned offset from the sun gear, and the planetary carrier is provided with a transmission unit that drives the oil pump. With this configuration, the oil pump is positioned offset from the sun gear, so the oil pump can be easily driven by a transmission unit provided on the planetary carrier, even though the oil pump and sun gear are positioned on separate axes. Furthermore, since the transmission unit drives only the oil pump, the axial thickness of the transmission unit can be easily reduced. This avoids the need to position the oil pump and sun gear coaxially, and makes it easier to shorten the transmission unit in the axial direction, providing a compact planetary gear transmission device with an oil pump.

[0051] (Configuration 2) The planetary gear transmission device according to configuration 1, wherein the oil pump is a trochoid type, and the transmission portion is a drive gear that meshes with a driven gear provided on a pump shaft of the oil pump. According to this configuration, the trochoid oil pump can be driven by a simple transmission mechanism, which prevents the structure from becoming complicated and the number of parts from increasing, making it easier to make the planetary gear transmission device more compact.

[0052] (Configuration 3) A planetary gear transmission device according to configuration 1 or 2, wherein the planetary carrier has a base portion on the opposite side of the planetary gear, and the drive gear is fixed to the base portion on the opposite side of the planetary gear. With this configuration, the layout can be designed so that the power transmission path through the planetary gear and the power transmission path to the oil pump are separated based on the base portion, which prevents the power transmission mechanism from becoming too complicated and makes it easier to make the planetary gear transmission device smaller.

[0053] (Configuration 4) The planetary gear transmission device according to any one of configurations 1 to 3, wherein the outer diameter of the drive gear is set within a range not exceeding the outer diameter of the planetary carrier. This configuration makes it possible to adjust the outer diameter of the pump drive gear within a range that does not exceed the outer diameter of the planetary carrier, while suppressing the increase in diameter of the planetary gear transmission device due to the influence of the pump drive gear, which is advantageous for improving design freedom.

[0054] (Configuration 5) The planetary gear transmission device according to configuration 3 or 4, further comprising a first bearing member that rotatably supports the base portion, and the oil pump is positioned radially outward of the first bearing member. This configuration avoids the situation where the oil pump and the first bearing member are aligned in the axial direction, which would increase the axial size of the planetary gear transmission device, and allows the space radially outside the first bearing to be effectively used as space for arranging the oil pump.

[0055] (Configuration 6) The planetary gear transmission device according to Configuration 5, wherein the oil pump is disposed in an area surrounded by the first bearing member, the planetary carrier, and the ring gear, and overlaps with the outermost position of the planetary carrier when viewed in the axial direction. According to this configuration, the oil pump, the first bearing member, the planetary carrier, and the ring gear can be arranged compactly, making it easier to further reduce the size of the planetary gear transmission device.

[0056] (Configuration 7) A planetary gear transmission device according to any one of configurations 1 to 6, wherein the casing has a divided structure including a first casing integrated with a drive source and a second casing connected to the first casing, and an oil passage connected to the oil pump is formed across the first casing and the second casing. According to this configuration, an oil passage can be formed using a casing with a split structure that is integrated with the drive source, which is advantageous for miniaturization, and it is also possible to separate the planetary gear transmission device and the drive source without draining the oil, which is advantageous for improving maintainability.

[0057] (Configuration 8) A planetary gear transmission device according to any one of configurations 1 to 7, wherein the casing has a divided structure including a first casing integrated with a drive source and a second casing connected to the first casing, and the first casing and the second casing rotatably support a pump shaft of the oil pump. According to this configuration, the pump shaft is supported by utilizing a casing with a split structure, which makes it easier to make the support structure for the pump shaft simple and compact, and makes it easier to make the planetary gear transmission device more compact.

[0058] (Configuration 9) The planetary gear transmission device according to any one of configurations 1 to 8, further comprising a plurality of oil discharge ports serving as discharge ports of the oil pump, and oil passages connected to the respective oil discharge ports. This configuration makes it easier to supply oil with high discharge pressure from the oil pump to multiple locations, making it easier to properly lubricate many locations.

[0059] (Configuration 10) A planetary gear transmission device according to any one of configurations 1 to 9, wherein the rotation axis of the planetary gear transmission device is oriented along the vertical direction, and the oil pump is immersed in oil that accumulates at the bottom of the casing. This configuration makes it easy to provide a planetary gear transmission device that is compact in the vertical direction while including an oil pump, and also makes it easy to ensure a reliable, uninterrupted supply of oil.

[0060] (Configuration 11) The planetary gear transmission device according to any one of configurations 1 to 10, which constitutes a power transmission mechanism between a rotor for vertical takeoff and landing of an aircraft and a drive source of the rotor. This configuration reduces the frontal projection area of ​​the aircraft body, making it easier to reduce air resistance during flight. [Explanation of symbols]

[0061] 1...aircraft, 2...rotor, 2M...motor (drive source), 10...planetary gear transmission device, 11...input shaft, 12...output shaft, 20...planetary gear mechanism, 21...sun gear, 22...planetary gear, 23...ring gear, 25...planetary carrier, 25B...base portion, 25Y1...first oil passage, 25Y2...second oil passage, 30...casing (gear casing), 31...first casing, 32 ...Second casing, 32X, 32Y, 33X...oil passage, 41...casing (motor casing), 42L...bearing (first bearing member), 42U...bearing (second bearing member), 50...oil pump, 51...pump shaft, 52...pump driven gear, 53...pressure delivery section, 60...pump drive gear (transmission section), 72A, 72B...oil discharge port, 74A, 74B...oil discharge passage, C1...center shaft.

Claims

1. A planetary gear transmission device including a sun gear housed in a casing, a plurality of planetary gears meshing with the sun gear at the outer periphery of the sun gear, and a ring gear meshing with the planetary gears at the outer periphery of the planetary gears, the ring gear is fixed to the casing so as not to rotate relative to the casing, and a planetary carrier that supports the planetary gears is supported on the casing so as to be rotatable relative to the casing around the sun gear, an oil pump that pumps oil as lubricating oil into the casing is disposed at a position offset from the sun gear; The planetary carrier is provided with a transmission unit that drives the oil pump, The rotation axis of the planetary gear transmission device is oriented along the vertical direction, the casing has a divided structure including a first casing at a lower level, a second casing at a middle level, and a third casing at an upper level, a pump shaft of the oil pump is rotatably supported by the first casing and the second casing; a first oil discharge port and a second oil discharge port, which are provided at different positions by a plurality of grooves on the upper surface of the first casing and serve as discharge ports of the oil pump; the oil from the first oil discharge port is supplied to the planetary carrier via an oil passage formed across the first casing, the second casing, and the third casing; The oil from the second oil discharge port is supplied to the sun gear via other oil passages formed in the first casing and the second casing. Planetary gear transmission.

2. A planetary gear transmission device as described in Claim 1, wherein an oil suction passage having one end connected to the oil suction port of the oil pump is a groove extending in a circular shape centered on the rotation axis of the planetary carrier and formed in the first casing.

3. A planetary gear transmission device as described in Claim 2, wherein an annular recessed portion is provided on the inner and outer peripheral walls of the second casing toward the oil intake passage.

4. A planetary gear transmission device as described in Claim 2, wherein the oil intake passage is formed as a groove extending annularly with a diameter corresponding to the outermost diameter position of the bearing of the planetary gear supported by the planetary carrier in the cross section of the rotating shaft in the planetary transmission device.

5. The oil pump is a trochoid type, 2. The planetary gear transmission device according to claim 1, wherein the transmission portion is a drive gear that meshes with a driven gear provided on a pump shaft of the oil pump.

6. 6. The planetary gear transmission device according to claim 5, wherein the planetary carrier has a base portion on the opposite side of the planetary gear, and the drive gear is fixed to the base portion on the opposite side of the planetary gear.

7. 7. The planetary gear transmission device according to claim 6, wherein the outer diameter of the drive gear does not exceed the outer diameter of the planetary carrier.

8. a first bearing member that rotatably supports the base portion; 8. The planetary gear transmission device according to claim 7, wherein the oil pump is located radially outward of the first bearing member.

9. 9. The planetary gear transmission device according to claim 8, wherein the oil pump is disposed in an area surrounded by the first bearing member, the planetary carrier, and the ring gear, and overlaps with the outermost position of the planetary carrier when viewed in the axial direction.

10. The planetary gear transmission device according to any one of claims 1 to 9, wherein the first casing is a casing that is integrated with a drive source.

11. 10. The planetary gear transmission device according to claim 1, wherein the oil pump is immersed in oil collected in a lower portion of the casing.

12. 10. The planetary gear transmission device according to claim 1, which constitutes a power transmission mechanism between a rotor for vertical takeoff and landing of an aircraft and a drive source of the rotor.

Images