Planetary gear device

Abstract

To provide a planetary gear device that efficiently prevents wear and seizure of planetary gear inside diameter parts and planetary gear end surfaces, and has a long product life.SOLUTION: A planetary gear device comprises: an internal gear formed in a ring shape; a sun gear located at a center of the internal gear; a plurality of planetary gears arranged via a carrier between the internal gear and the sun gear; needle bearings interposed between supporting shafts provided in the carrier, and the planetary gears pivotally supported by the supporting shafts; and washers inserted onto the supporting shafts, and arranged between the carrier and end surfaces of the needle bearings. Treated parts for reducing wear are formed in bearing contact surfaces on which the washers are in contact with the end surfaces of the needle bearings.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, wind power generation equipment has been known that can start rotating a wind turbine even in weak winds by installing a speed-increasing gear consisting of a planetary gear set between the wind turbine and the rotating shaft. The planetary gear set has a housing, an internal gear, a sun gear, and a carrier housed within the housing, and these rotating elements are arranged concentrically around the output shaft. Furthermore, planetary gears that mesh with the internal gear and sun gear are rotatably supported via bearing rollers on a support shaft fixed to the carrier. As a result, when the planetary gear rotates, the internal gear and sun gear rotate synchronously, and when the planetary gear does not rotate, the internal gear and sun gear rotate together.

[0003] Patent Document 1 discloses a planetary gear device in which a friction washer is provided between the end face of at least one of the internal gear, sun gear, and planetary gear and a member that rotates relative to this gear, and is in sliding contact with at least one of the gears. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4241189 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the planetary gear device described in Patent Document 1, the provision of wear washers can prevent early wear and seizure of each gear, such as the sun gear and planetary gears. However, there is a problem in that the durability may not be sufficient for equipment that places a large load on the rotating shaft, such as the wind power generation equipment described above.

[0006] The present invention aims to provide a planetary gear device that allows planetary gears to rotate smoothly, reduces friction between the planetary gears and planet carriers, and more efficiently prevents wear and seizure of the inner diameter portions of the planetary gears and the end faces of the planetary gears, resulting in a long product life. [Means for solving the problem]

[0007] The above object of the present invention can be achieved by the following configuration. (1) An internal gear formed in a ring shape; a sun gear located at the center of the internal gear; a plurality of planetary gears disposed between the internal gear and the sun gear via a carrier; a needle bearing interposed between a support shaft provided on the carrier and the planetary gear journaled on the support shaft; a washer inserted through the support shaft and disposed between the carrier and the end surface of the needle bearing, a bearing contact surface of the washer that comes into contact with the end surface of the needle bearing is subjected to a treatment for reducing friction; Planetary gear device. [Effects of the Invention]

[0008] According to the present invention, the needle bearings provided between the planetary gears and the support shafts and the washers provided on the support shafts can efficiently prevent wear and seizure of the inner diameter portions and end faces of the planetary gears, thereby making the planetary gears drive smoother and lengthening the product life of the entire device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a wind turbine generator including a planetary gear device. [Figure 2] FIG. 2 is an exploded view of the planetary gear unit. [Figure 3] FIG. 3 is a perspective view of a main part of the planetary gear device. [Figure 4] 4(a) to 4(d) are diagrams showing the operating principle of the planetary gear device. [Figure 5] FIG. 5 is a diagram showing a state in which the needle bearing is incorporated into a planetary gear device. [Figure 6] FIG. 6 is a schematic diagram of a wind turbine generator according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A wind turbine generator to which the present invention is applied will be described in detail below with reference to the drawings. Fig. 1 is a schematic diagram of a wind turbine generator including a planetary gear device. Fig. 2 is an exploded view of the planetary gear device. Fig. 3 is a perspective view of the main part of the planetary gear device. Figs. 4(a) to 4(d) are diagrams showing the operating principle of the planetary gear device. Fig. 5 is a diagram showing the state in which a needle bearing is incorporated into the planetary gear device.

[0011] The wind power generation system 100 includes a wind turbine 20, a generator 13, and a gearbox 17. This wind power generation system 100 is a wind power generation system equipped with a vertical axis wind turbine 20 having an input shaft 16 that is installed vertically. In the wind power generation system 100, the rotation of the wind turbine 20 is input to the gearbox 17 via the input shaft 16, and the rotation accelerated by the gearbox 17 is transmitted to the generator 13 via the output shaft 18, and the transmitted rotation (power) causes the generator 13 to generate electricity.

[0012] The wind turbine 20 is a vertical axis wind turbine such as a Darrieus-type lift wind turbine. This wind turbine 20 has multiple blades 21. Each blade 21 is formed in a curved shape, and both ends are connected to the input shaft 16. The blades 21 are arranged at equal intervals around the axis of the input shaft 16, which extends vertically. When the blades 21 receive wind, the wind turbine 20 rotates in one direction around the axis of the input shaft 16.

[0013] The speed-up gear 17 is provided between the wind turbine 20 and the generator 13. The speed-up gear 17 increases the shaft rotation of the input shaft 16 that accompanies the rotation of the wind turbine 20, and outputs the increased shaft rotation to the output shaft 18. The speed-up gear 17 houses a planetary gear unit 4, which will be described later.

[0014] Next, the planetary gear device 4 constituting the speed increaser 17 will be described with reference to Figs. 2 to 5. Fig. 2 is an exploded view of the planetary gear device. Fig. 3 is a perspective view of the main part of the planetary gear device. Figs. 4(a) to 4(d) are diagrams showing the operating principle of the planetary gear device. Fig. 5 is a diagram showing the state in which a needle bearing is incorporated into the planetary gear device.

[0015] The planetary gear device 4 has an internal gear (ring gear) 4a with internal teeth, a sun gear (sun gear) 4b with external teeth, three planetary gears (pinion gears) 4c that mesh with the internal gear 4a and the sun gear 4b, and a carrier 4d on which support shafts (pinion shafts) 4e that axially support each planetary gear 4c are mounted, and these are all housed within a housing (gear box) not shown. The carrier 4d is formed in an annular shape that can rotate around the same axis as the internal gear 4a, and three support shafts 4e are provided at equal intervals. This configuration can be seen in FIG. A needle bearing 10 is provided between the support shaft 4e and the planetary gear 4c to rotatably support the outer ring side planetary gear 4c on the support shaft 4e on the inner ring side. This configuration can be seen in Figure 5. Figures 4(a) to 4(d) show an example of a general operation of the planetary gear device 4.

[0016] In this embodiment, the speed increaser 17 is attached and fixed to the generator 13 by fastening it to a flange (not shown) provided on the generator 13 via a flange (not shown) provided on the outer peripheral surface of the end of the gearbox (not shown). The planetary gear device 4 in the gearbox has the sun gear 4b connected to the output shaft 18 as the driven side, the planetary gear 4c (carrier 4d) connected to the input shaft 16 as the drive side, and the internal gear 4a fixed, thereby obtaining a speed-up ratio. This allows the planetary gear device 4 to be used as a speed increasing mechanism.

[0017] The needle bearing 10 consists of multiple rollers 11 and a needle roller bearing cage (hereinafter simply referred to as "cage") 12 that holds the rollers 11. An oil passage 12f is formed in the support shaft 4e, extending along the axis from the right in Figure 5 and exiting the outer periphery in the center, through which lubricating oil is supplied. The cage 12 is also used for outer ring guidance. In addition, a washer 4g is disposed between the carrier 4d and the end face of the planetary gear 4c. For this configuration, please refer to Figures 3 and 5.

[0018] The cage 12 has a configuration in which a pair of annular portions 12a are connected by multiple pillar portions 12b. The spaces between adjacent pillar portions 12b form pockets that hold the rollers 11. Each pillar portion 12b has a reduced-diameter portion 12c in the axial center (i.e., close to the axis of the cage 12) that is reduced in diameter, and the outer peripheral surface that expands in diameter from both axial sides of the reduced-diameter portion 12c toward the annular portion 12a serves as an outer diameter guide surface 12d that comes into sliding contact with the outer ring.

[0019] The washer 4g is made of an annular plate material and is inserted onto the support shaft 4e to be disposed between the end face of the needle bearing 10 and the carrier 4d. The washer 4g prevents direct contact between the end face of the needle bearing 10 and the carrier 4d. More specifically, the washer 4g is in contact with the end face of the annular portion 12a of the retainer 12 of the needle bearing . In addition, the washer 4g has a treated portion 15 formed by processing the entire bearing contact surface, which is one of the pair of surfaces and comes into contact with the end face of the annular portion 12a of the retainer 12 of the needle bearing .

[0020] The treated portion 15 of the bearing contact surface is formed by low-friction treatment using molybdenum disulfide or the like. According to this configuration, by providing a washer 4g and forming a processing portion 15 on the bearing contact surface of the washer 4g, the sliding resistance between the washer 4g and the end face of the needle bearing 10 is reduced, thereby further extending the product life of the planetary gear device.

[0021] The treated portion 15 on the bearing contact surface may be formed by texturing such as shot peening. This configuration makes it easier for a lubricating oil film to be maintained on the bearing contact surface of the washer 4g, and the thickness of the oil film increases, thereby reducing the sliding resistance between the washer 4g and the end face of the needle bearing 10, thereby extending the product life of the planetary gear unit 4.

[0022] Furthermore, by applying the planetary gear device 4 equipped with the needle bearing 10 described above to the speed increaser 17 of the wind power generation device 100 having the wind turbine 20, which is a vertical wind turbine, the rotation of the wind turbine 20 becomes smoother. More specifically, even if fretting occurs due to vibrations caused by the wind W or the weight of the wind turbine 20 and input shaft 16 being applied to the speed increaser 17, the sliding resistance between the washer 4g and the end face of the needle bearing 10 is reduced, resulting in smooth rotation of the input shaft 16. As a result, even if the amount of wind W hitting the wind turbine 20 (wind speed) is weak, the wind turbine 20 and input shaft 16 can rotate more easily, and the power generation efficiency of the wind turbine generator 100 is also improved.

[0023] In addition, the washer 4g may be configured so that the processing portion 15 contacts only the end face of the retainer 12 and does not contact the end face of the pinion gear by reducing the radial size or extending the axial direction of the needle bearing retainer 12, etc.

[0024] Next, a wind turbine generator 200 according to a second embodiment of the present invention will be described in detail with reference to Fig. 6. Fig. 6 is a schematic diagram of the wind turbine generator according to the second embodiment.

[0025] The wind turbine 40 is a horizontal axis wind turbine such as a propeller-type lift wind turbine. The wind turbine 40 has multiple blades 41. Each blade 41 is formed in a curved shape, and one end is connected to the input shaft 16. The blades 41 are arranged at equal intervals around the axis of the input shaft 16, which extends horizontally. When the blades 41 receive wind, the wind turbine 40 rotates in one direction around the axis of the input shaft 16.

[0026] The present invention is not limited to the above-described embodiments, and modifications and improvements are possible as appropriate.

[0027] As described above, the present specification discloses the following: (1) an internal gear formed in a ring shape; a sun gear located at the center of the internal gear; a plurality of planetary gears disposed between the internal gear and the sun gear via a carrier; a needle bearing interposed between a support shaft provided on the carrier and the planetary gear journaled on the support shaft; a washer inserted through the support shaft and disposed between the carrier and the end surface of the needle bearing, a bearing contact surface of the washer that comes into contact with the end surface of the needle bearing is subjected to a treatment for reducing friction; Planetary gear device. According to this configuration, the needle bearings provided between the planetary gears and the support shafts and the washers provided on the support shafts can efficiently prevent wear and seizure on the inner diameter portions and end faces of the planetary gears, thereby enabling smoother drive of the planetary gears and extending the product life of the entire device.

[0028] (2) The bearing contact surface of the washer is subjected to low-friction treatment using molybdenum disulfide. The planetary gear device according to (1). According to this configuration, the washer and the end face of the needle bearing slide smoothly, so that wear and seizure of the inner diameter portion of the planetary gear and the end face of the planetary gear can be effectively prevented.

[0029] (3) The bearing contact surface of the washer is textured. The planetary gear device according to (1). According to this configuration, lubricating oil is more easily retained on the bearing contact surface of the washer, and the oil film increases, thereby efficiently preventing wear and seizure of the inner diameter portion and end faces of the planetary gears.

[0030] (4) Vertical axis wind turbines; a speed increaser to which the rotation of the wind turbine is input; a generator to which the rotation increased in speed by the speed increaser is transmitted and which generates electricity by the transmitted rotation, The speed increaser accommodates the planetary gear device according to any one of (1) to (3). A wind power generation device using a vertical wind turbine.

[0031] (5) Horizontal axis wind turbines; a speed increaser to which the rotation of the wind turbine is input; a generator to which the rotation increased in speed by the speed increaser is transmitted and which generates electricity by the transmitted rotation, The speed increaser accommodates the planetary gear device according to any one of (1) to (3). A wind power generation device using a horizontal wind turbine. [Explanation of symbols]

[0032] 4 Planetary gear unit 4a Internal gear 4b Sun gear 4c planetary gear 4d career 4e Support shaft 4g washer 10 Needle bearings Around 11 12 Cage 12a Annular section 12b Column 12c Reduced diameter part 12d Outer diameter guideway 12f oil passage 13. Generator 15 Processing section 16 Input shaft 17 Gearbox 18 Output shaft 20 windmill 21 Feather 100 Wind power generation equipment

Claims

1. an internal gear formed in a ring shape; a sun gear located at the center of the internal gear; a plurality of planetary gears disposed between the internal gear and the sun gear via a carrier; a needle bearing interposed between a support shaft provided on the carrier and the planetary gear journaled on the support shaft; a washer inserted through the support shaft and disposed between the carrier and the end surface of the needle bearing, a bearing contact surface of the washer that comes into contact with the end surface of the needle bearing is subjected to a treatment for reducing friction; Planetary gear device.

2. The bearing contact surface of the washer is subjected to low friction treatment using molybdenum disulfide.

2. The planetary gear device according to claim 1.

3. The bearing contact surface of the washer is textured.

2. The planetary gear device according to claim 1.

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