Power circulation type load test equipment

Abstract

To provide a power circulation type load test device capable of preventing damage to sliding bearings even when the planetary gear mechanism itself is constituted with a power circulation type load test device.SOLUTION: The power circulation type load test device includes: a casing 12; a rotation shaft 14; a first sun gear 18a and a second sun gear 20a placed in an inner space of the casing 12; a first planetary gear 18b with the gear support shaft 24 in the planet carrier 18c, which meshes with the first sun gear 18a; a second planetary gear 20b with a gear support shaft 26 on an inner wall of the casing 12 which meshes with a second sun gear 20a; and an internal gear 22 arranged rotatably on a rotation shaft 14; and a load generating unit 28 fixed to the casing 12 for controlling the rotation state of the planet carrier 18c.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power circulation type load testing device, and more particularly to a testing device for testing planetary gears as load tests. [Background technology]

[0002] Power circulation load testing machines are known as devices for testing the strength and durability of power transmission components such as gears, rotating shafts, and belts. Among such power circulation load testing machines, those employing planetary gears in their power transmission paths are known, as disclosed in Patent Documents 1 and 2. The power circulation load testing machine disclosed in Patent Document 1 is a testing machine for rotating shafts, and connects the rotating shaft to a sun gear and configures a power circulation mechanism via gears that can mesh with the planet carrier. Furthermore, an external gear is formed on the outer periphery of an internal gear that meshes with the planet gear, and a gear meshing with this external gear is arranged. A torque loading device is engaged with this gear, thereby creating a rotational difference between the sun gear and the power circulation mechanism via the internal gear and the planet gear, thereby applying torsion to the rotating shaft.

[0003] Furthermore, the power circulation type load testing device disclosed in Patent Document 2 employs a planetary gear as a mechanism for adjusting the load torque in the power circulation path that constitutes the closed path. With a power circulation type load testing device configured in this way, it is possible to apply torque to the closed path by using the rotation difference between the input side rotating shaft and the output side rotating shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 18739 / 1983 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-7902 Summary of the Invention [Problem to be solved by the invention]

[0005] The power circulation load testing device disclosed in the above patent document is configured to adjust the torque loaded on the device by using planetary gears as part of the device. However, there have been no attempts to apply the planetary gear mechanism itself alone to a power circulation load testing device, and power circulation load testing devices configured in this way have had problems such as difficulty in adjusting torque during testing and an inability to form an oil film on the bearing metal (slide bearing) of the planetary gear, which can result in damage.

[0006] Therefore, an object of the present invention is to provide a power circulation type load testing device that can prevent damage to sliding bearings even if the power circulation type load testing device is constructed using only the planetary gear mechanism itself. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the power circulation load testing device of the present invention is characterized by comprising a casing, a rotating shaft that penetrates the internal space of the casing and has an input portion on the outside, a first sun gear and a second sun gear that are arranged in the internal space of the casing and spaced apart along the longitudinal direction of the rotating shaft, a planetary carrier that can rotate around the rotating shaft and is provided with a gear support shaft, a first planetary gear that meshes with the first sun gear, a second planetary gear that is provided with a gear support shaft on the inner wall of the casing and meshes with the second sun gear, an internal gear that has internal teeth that mesh with the first planetary gear and the second planetary gear in the internal space of the casing and is arranged rotatable around the rotating shaft, and a load generating device that is fixed to the casing and controls the rotational state of the planetary carrier.

[0008] In the power circulation type load testing device having the above-mentioned features, the planetary carrier may be provided with a load-applying gear, and the load generating device may be provided with a load adjusting gear that meshes with the load-applying gear. With such features, by rotating the load adjusting gear of the load generating device, the planetary carrier can be rotated, thereby generating a load on the power circulation mechanism.

[0009] In addition, in the power circulation type load testing device having the above-mentioned characteristics, the load generating device may be provided with an adjustment lever that rotates the load adjustment gear and an adjustment mechanism that positions the adjustment lever. With such a characteristic, it is possible to fine-tune the adjustment lever and maintain the load state via the adjustment mechanism. [Effects of the Invention]

[0010] According to a power circulation type load testing apparatus having the above-described characteristics, even if the power circulation type load testing apparatus is configured using only the planetary gear mechanism itself, damage to the sliding bearing can be prevented. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a power circulation load testing device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a configuration of a load generating device. [Figure 3] FIG. 10 is a cross-sectional view showing the state of an oil film formed between a rotating shaft of a planetary gear and a sliding bearing when the power circulation load testing device according to the embodiment is not in operation. [Figure 4] FIG. 4 is a cross-sectional view showing the state of an oil film formed between a rotating shaft of a planetary gear and a sliding bearing when the power circulation load testing device according to the embodiment is operated. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the power circulation type load testing apparatus of the present invention will be described in detail with reference to the drawings. Note that the embodiments shown below are only some of the preferred forms for carrying out the present invention, and even if some of the configuration is changed, they can be considered as part of the present invention as long as the effects of the invention are achieved.

[0013] [composition] First, the configuration of a power circulation load testing apparatus according to this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing the schematic configuration of the power circulation load testing apparatus according to this embodiment, and FIG. 2 is a diagram illustrating the configuration of a load generating device. The power circulation load testing apparatus 10 according to this embodiment is basically composed of a casing 12, a rotating shaft 14, a pair of planetary gear mechanisms, and a load generating device 28. The casing 12 is a container having an internal space formed by placing a first cover 12b and a second cover 12c at the end of a cylindrical body 12a. The casing 12 supports the rotating shaft 14 (described in detail below) and accommodates the pair of planetary gear mechanisms in the internal space. While the casing 12 does not necessarily need to be hermetically sealed, it is desirable for it to be able to shield the internal space containing the rotating body from the external space in terms of dust and safety.

[0014] Rotating shaft 14 is a long rotating body that penetrates the internal space of casing 12, with at least a portion of it disposed in the external space, and serves as input portion 14a. Bearings 16a and 16b are provided at the intersection of casing 12 and rotating shaft 14 (between first cover 12b and second cover 12c in the embodiment shown in FIG. 1), respectively, allowing rotating shaft 14 to rotate independently within the internal space of the casing.

[0015] The pair of planetary gear mechanisms includes a first planetary gear mechanism consisting of a first sun gear 18a, a first planetary gear 18b, a planet carrier 18c, and an internal gear 22, and a second planetary gear mechanism consisting of a second sun gear 20a, a second planetary gear 20b, and the internal gear 22. The first sun gear 18a is a gear that is arranged on the rotary shaft 14 (on the input portion 14a side in the embodiment shown in FIG. 1), and multiple first planetary gears 18b are gears that are arranged on the outer periphery of the first sun gear 18a so as to mesh with the first sun gear 18a. In this embodiment, the gear support shafts 24 of the multiple first planetary gears 18b are positioned via the planet carrier 18c, which will be described in detail later, so that the gear support shafts 24 of each of the multiple first planetary gears 18b are arranged on the circumference of a single circle that is concentric with the first sun gear 18b.

[0016] The planetary carrier 18c is an element for positioning the gear support shaft 24 of the first planetary gear 18b, and in this embodiment is disposed between the internal gear 22 and the first cover 12b, with a bearing 16c provided between it and a boss provided on the first cover 12b, and is disposed so as to be able to impart individual rotation to the rotating shaft 14 and the casing 12. Furthermore, the planetary carrier 18c according to this embodiment is provided with a stepped portion on the surface facing the first cover 12b, and a load-applying gear 18c1 is provided on the outer periphery of this stepped portion.

[0017] The second sun gear 20a is a gear that is arranged at a position separated from the first sun gear 18a with respect to the rotation axis 14, and multiple second planetary gears 20b are gears that are arranged on the outer periphery of the second sun gear 20a so as to mesh with the second sun gear 20a. In this embodiment, the gear support shafts 26 of the multiple second planetary gears 20b are arranged on the second cover 12c so that they are arranged on the circumference of a single circle that is concentric with the second sun gear 20a.

[0018] The internal gear 22 is an element that meshes with each of the multiple first planetary gears 18b and the multiple second planetary gears 20b, and transmits power generated between them. The internal gear 22 according to this embodiment has first internal teeth 22a that mesh with the first planetary gears 18b and second internal teeth 22b that mesh with the second planetary gears 20b.

[0019] Here, a plain bearing 40 is provided between the first planetary gear 18b and the gear support shaft 24, and between the second planetary gear 20b and the gear support shaft 26, respectively.

[0020] The load generator 28 is an element for generating a load on the power circulation mechanism formed by the rotating shaft 14, the first sun gear 18a, the first planetary gears 18b, the internal gear 22, the second planetary gears 20b, and the second sun gear 20a. In this embodiment, by restricting the free rotation of the planetary carrier 18c with the casing 12 as the starting point and imparting a predetermined rotation to the planetary carrier 18c, a torque that generates a load is applied to the power transmission mechanism between the rotating shaft 14 and the internal gear 22, i.e., between the first sun gear 18a and the first planetary gear 18b, the first planetary gear 18b and the first internal gears 22a, the second sun gear 20a and the second planetary gear 20b, and the second planetary gear 20b and the second internal gears 22b.

[0021] Specifically, the load generator 28 includes a load adjustment gear 30, an adjustment lever 32, and an adjustment mechanism 34. The load adjustment gear 30 is an element that restricts the free rotation of the planetary carrier 18c and also applies the desired rotation. In this embodiment, the load adjustment gear 30 is disposed so as to mesh with a load-applying gear 18c1 provided on the outer periphery of the planetary carrier 18c.

[0022] The adjustment lever 32 is an element that supports the load adjustment gear 30 and is exposed to the outside of the casing 12, causing the load adjustment gear 30 to rotate when the lever swings. Note that the rotation shaft 32a of the adjustment lever 32 (the shaft that supports the load adjustment gear 30) is positioned on the first cover 12b, which restricts the free rotation of the planetary carrier 18c having the load-applying gear 18c1 that meshes with the load adjustment gear 30.

[0023] The adjustment mechanism 34 is an element for positioning the adjustment lever 32 and determining the amount of load applied. The swinging portion of the adjustment lever 32 is located between both wall surfaces 36a of a U-shaped bracket 36, and a bolt 38 is screwed from both wall surfaces 36a toward the swinging portion of the adjustment lever 32. With the adjustment mechanism 34 configured in this way, it is possible to control the swing amount of the adjustment lever 32 and position it by tightening or loosening the bolt 38 screwed into the wall surface 36a.

[0024] In the power circulation load testing device 10 according to this embodiment, a first physical quantity detecting means such as an acceleration sensor (not shown) is provided on any of the first sun gear 18a, second sun gear 20a, first planetary gear 18b, second planetary gear 20b, internal gear 22, sliding bearing 40, and gear support shafts 24 and 26, thereby enabling detection of changes in vibration acceleration. With this configuration, it becomes possible to detect the value (natural frequency) at which the vibration acceleration peaks.

[0025] Furthermore, the power circulation type load measurement device 10 is configured such that a second physical quantity detection means, such as a strain gauge, is provided at the tooth root of any of the first sun gear 18a, second sun gear 20a, first planetary gear 18b, second planetary gear 20b, and internal gear 22. This allows the stress generated at the tooth root to be calculated when the rotation speed or circulation power is changed, thereby enabling confirmation of the dynamic load. This configuration makes it possible to compare the actual measured values (calculated values based on the detected physical quantities) of the dynamic load and natural frequency acting on each gear (the gear being measured) during operation with the calculated values (theoretical values based on the design conditions). Therefore, if a discrepancy occurs between the actual measured values and the calculated values, a calculation method for determining the gear dynamic load can be developed by adding a correction factor to the calculation formula to correct the discrepancy.

[0026] [Effect] In the power circulation load test apparatus 10 configured as described above, tests are performed using the second sun gear 20a, the second planetary gear 20b, and the second internal gear 22 as test specimens. In the power circulation load test apparatus 10, first, rotation is applied to the input portion of the rotating shaft 14 in an unloaded state to rotate the rotating shaft. As a result, power is transmitted to the first planetary gear 18b and the second planetary gear 20b via the first sun gear 18a and the second sun gear 20a attached to the rotating shaft 14, and then to the internal gear 22, thereby completing power circulation.

[0027] After continuing operation under no load for a predetermined time, the adjustment lever 32 is rotated via the adjustment mechanism 34 of the load generating device 28, and the planetary carrier 18c is rotated via the load-applying gear 18c1 that meshes with the load adjustment gear 30, thereby generating a load on the power circulation mechanism of the power circulation type load testing device 10.

[0028] The load applied via the load generator 28 can be increased or decreased depending on the operating state (rotation state) of the power circulation type load testing device 10 so that a desired load can be applied to the test specimen.

[0029] [effect] In a power circulation type loading device not equipped with the load generating device 28 described above, in order to apply a load to a test sample, it is necessary to apply a load to two sets of planetary gears (elements corresponding to the first planetary gear 18b and the second planetary gear 20b in this embodiment) in advance during the assembly stage. In this assembled state, a load acts between the gear support shaft and the plain bearing even when the gears are stationary. However, when the gears are stationary, as shown in FIG. 3 (the components in this embodiment are labeled with reference numerals), an oil film may not be formed between the gear support shaft 24 of the first planetary gear 18b and the plain bearing 40, or between the gear support shaft 26 of the second planetary gear 20b and the plain bearing 40. Rotating the planetary gears (the first planetary gear 18b and the second planetary gear 20b in this embodiment) without an oil film between them may cause damage (galling) to the plain bearing (the plain bearing 40 in FIG. 3).

[0030] On the other hand, when the load generator 28 is attached to the power circulation load testing apparatus 10 as in the above embodiment, it becomes possible to apply a load to the test specimen after operating it in an unloaded state. Therefore, after operating the power circulation load testing apparatus 10 in an unloaded state and forming a wedge oil film as shown in FIG. 4 to achieve a good lubrication state between the gear support shafts 24, 26 and the sliding bearing 40, a load can be applied to the power circulation mechanism. Therefore, even if a load is applied to the power circulation mechanism, there is no risk of damage or the like occurring between the gear support shafts 24, 26 and the sliding bearing 40. [Industrial Applicability]

[0031] In the above embodiment, the load generating device 28 is configured to be manually operated in order to simplify the mechanism. However, the configuration and control of the load generating device 28 are not limited to this. In other words, any configuration is acceptable as long as it can rotate the planetary carrier 18c at any timing and maintain that rotated state. Furthermore, the power source for operation may be electric or hydraulic. [Explanation of symbols]

[0032] 10...Power circulation type load test apparatus, 12...Casing, 12a...Body, 12b...First cover, 12c...Second cover, 14...Rotating shaft, 14a...Input section, 16a, 16b, 16c...Bearings, 18a...First sun gear, 18b...First planetary gear, 18c...Planet carrier, 18c1...Load-applying gear, 20a...Second sun gear, 20b...Second planetary gear, 22...Internal gear, 22a...First internal teeth, 22b...Second internal teeth, 24...Gear support shaft, 26...Gear support shaft, 28...Load generating device, 30...Load adjusting gear, 32...Adjusting lever, 32a...Rotating shaft, 34...Adjusting mechanism, 36...Bracket, 36a...Wall surface, 38...Bolt, 40...Plain bearing.

Claims

1. A casing; a rotating shaft that passes through the internal space of the casing and has an input portion provided on the outside; a first sun gear and a second sun gear arranged in an internal space of the casing and spaced apart from each other along the longitudinal direction of the rotation shaft; a planetary carrier rotatable around the rotation axis and provided with a gear support shaft; and a first planetary gear meshing with the first sun gear; a second planetary gear having a gear support shaft provided on an inner wall of the casing and meshing with the second sun gear; an internal gear that has internal teeth that mesh with the first planetary gear and the second planetary gear and is arranged rotatably around the rotation shaft in the internal space of the casing; a load generating device fixed to the casing and controlling the rotation state of the planetary carrier.

2. the planet carrier includes a load-applying gear; 2. The power circulation type load testing apparatus according to claim 1, wherein the load generating device includes a load adjusting gear that meshes with the load applying gear.

3. The load generating device includes an adjustment lever that rotates the load adjustment gear; 3. A power circulation type load testing device according to claim 2, further comprising an adjustment mechanism for positioning said adjustment lever.

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