Gearing

Abstract

To provide a gear device capable of reducing restrictions on design.SOLUTION: A gear device 100 has a first gear 12, a pinion shaft 14 supporting the first gear 12, a second gear 22 meshing with the first gear 12, and a gear shaft 24 rotating on an axis Lb of rotation orthogonal to or at a skew position with an axis La of rotation of a pinion shaft 14 to support the second gear 22, and has a support part 30 which supports the pinion shaft 14 on the side of the second gear 22, and the support part 30 is supported by the gear shaft 24.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Mechanical devices using bevel gears are known. For example, Patent Document 1 describes a multi-stage angled joint having a casing, a drive shaft, a driven shaft, and a plurality of reduction stages. This device has a reduction stage defined by a pair of gears defined by a bevel pinion and a bevel annular gear, and includes a mechanism for maintaining the relative positions of the axis of the drive shaft and the axis of the driven shaft unchanged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-329200 Summary of the Invention [Problem to be solved by the invention]

[0004] The device described in Patent Document 1 supports the pinion shaft at both ends, and a shaft supporting the second gear is disposed on the tip side of the pinion shaft. In this device, since the pinion shaft is supported at both ends, the bearings are disposed so as not to interfere with the shaft supporting the second gear and are supported by the casing. For this reason, this device has significant design constraints, such as limited bearing capacity.

[0005] SUMMARY OF THE PRESENT EMBODIMENT In view of the above problems, an object of the present invention is to provide a gear device that can reduce design constraints. [Means for solving the problem]

[0006] In order to solve the above problems, a gear device according to one embodiment of the present invention is a gear device having a first gear, a pinion shaft supporting the first gear, a second gear meshing with the first gear, and a gear shaft supporting the second gear and rotating about a rotation axis that is perpendicular or twisted relative to the rotation axis of the pinion shaft, and has a support portion that supports the second gear side of the pinion shaft. The support portion is supported by the gear shaft.

[0007] Any combination of the above components, or mutual substitution of the components or expressions of the present invention between methods, systems, etc. are also valid aspects of the present invention. Effect of the Invention

[0008] According to the present invention, a gear device capable of reducing design constraints can be provided. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a side view of the gear device of the first embodiment. [Diagram 2] FIG. 2 is a plan view of the gear unit of FIG. 1. [Diagram 3] FIG. 11 is a side view of a gear device according to a second embodiment. [Figure 4] FIG. 4 is a plan view of the gear unit of FIG. 3.

[0010] The present invention will be described below based on preferred embodiments with reference to the drawings. In the embodiments and modified examples, the same or equivalent components and members are given the same reference numerals, and duplicated descriptions are omitted as appropriate. The dimensions of the members in each drawing are enlarged or reduced as appropriate for ease of understanding. Some of the members that are not important for explaining the embodiments are omitted in each drawing.

[0011] In addition, terms including ordinal numbers such as first, second, etc. are used to describe various components, but these terms are used only for the purpose of distinguishing one component from another component, and the components are not limited by these terms.

[0012] First, an overview of the present invention will be described. In a gear device having two bevel gears that mesh with each other, when a load is applied, the bevel gears are displaced due to the meshing force between the bevel gears, causing misalignment. When misalignment occurs, the tooth contact positions of the bevel gears fluctuate, and the V-axis displacement in particular becomes large. Such a change in the tooth contact position can cause tooth contact abnormalities such as one-sided contact. In particular, a pinion shaft with a cantilever structure is more affected by misalignment than a gear shaft that is supported on both sides by bearings, and therefore the V-axis displacement becomes large. This problem is not limited to bevel gears, but can also occur in gear devices with other structures such as hypoid gears in which the input and output shafts are in a twisted position.

[0013] Based on these findings, the present inventors have devised a configuration in which an extension shaft is provided on the pinion shaft and supported by a bearing contained in a cross joint supported by the gear shaft, in order to reduce misalignment of the pinion shaft, particularly the V-axis displacement amount (in this example, the Z-axis deviation amount in the drawing), which has a large effect on tooth contact position fluctuation. By supporting the extension shaft of the pinion shaft on the gear shaft via the bearing, the pinion shaft has a double-supported structure and the rigidity of the pinion shaft is increased. By increasing the rigidity of the pinion shaft, the V-axis displacement of the pinion shaft is reduced, tooth contact position fluctuation is suppressed, and one-sided contact can be reduced. Hereinafter, a detailed description will be given with reference to an embodiment.

[0014] [First embodiment] A gear train 100 according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a side view of the gear train 100. Fig. 2 is a plan view of the gear train 100. As an example, the gear train 100 can be suitably used in a mechanism for transmitting power between two intersecting shafts or two shafts in a twisted position in a belt conveyor, elevator, or the like.

[0015] For ease of explanation, an XYZ Cartesian coordinate system is defined as shown in the figure, with a certain horizontal direction being the X-axis direction, a horizontal direction perpendicular to the X-axis direction being the Y-axis direction, and a vertical direction perpendicular to both being the Z-axis direction. The positive directions of the X-axis, Y-axis, and Z-axis are defined as the directions of the arrows in each figure, and the negative directions are defined as the directions opposite to the arrows. These directional notations do not limit the orientation in which the gear device 100 is used, and the gear device 100 can be used in any orientation depending on the application.

[0016] As shown in Figs. 1 and 2, the gear device 100 includes a first gear section 10, a first stage shaft section 20, and a support section 30. The first gear section 10 includes a first gear 12 and a pinion shaft 14 supporting the first gear 12. The first stage shaft section 20 includes a second gear 22 meshing with the first gear 12, and a gear shaft 24 supporting the second gear 22. The support section 30 supports the second gear 22 side of the pinion shaft 14. The support section 30 is supported by the gear shaft 24. The rotation axis Lb of the gear shaft 24 is perpendicular to or twisted with respect to the rotation axis La of the pinion shaft 14.

[0017] In this embodiment, the first gear 12 and the second gear 22 are bevel gears. The rotation axis La of the pinion shaft 14 is along the X-axis, and the rotation axis Lb of the gear shaft 24 is along the Y-axis. Therefore, in this example, the rotation axis La and the rotation axis Lb are perpendicular to each other.

[0018] The pinion shaft 14 has a second gear side shaft portion 141 on the second gear 22 side (X-axis positive direction side) of the first gear 12, and an anti-second gear side shaft portion 142 on the anti-second gear 22 side (X-axis negative direction side) of the first gear 12. The second gear side shaft portion 141 is a portion supported by the support portion 30, and the anti-second gear side shaft portion 142 is a portion located on the opposite side to the second gear side shaft portion 141 across the first gear 12. In this embodiment, the second gear side shaft portion 141 has a smaller diameter than the anti-second gear side shaft portion 142.

[0019] The pinion shaft 14 is rotatably supported by the pinion shaft housing 17 by the pinion shaft bearings 15, 16, 18 that support the shaft portion 142 opposite to the second gear. The first and second pinion shaft bearings 15, 16 are accommodated in a second accommodation recess 172 of the pinion shaft housing 17, and the third pinion shaft bearing 18 is accommodated in a first accommodation recess 173 of the pinion shaft housing 17. The first accommodation recess 173 is disposed in the vicinity of the first gear 12, and the second accommodation recess 172 is disposed away from the first accommodation recess 173 on the opposite side of the first gear 12. A retaining ring 13 that restricts the axial movement of the third pinion shaft bearing 18 is fixed to the pinion shaft 14. A housing cover 19 that restricts the axial movement of the first and second pinion shaft bearings 15, 16 is provided at the end of the pinion shaft housing 17 farther from the first gear 12. The pinion shaft 14 passes through the center of the housing lid 19 .

[0020] Although there is no limitation on the configuration of the pinion shaft bearings 15, 16, 18, in this embodiment, the pinion shaft bearings 15, 16, 18 are angular roller bearings capable of supporting radial and thrust forces. In this example, the first pinion shaft bearing 15 and the second pinion shaft bearing 16 on the first gear 12 side of the first pinion shaft bearing 15 are arranged face to face. With this configuration, the pinion shaft bearings 15, 16, 18 can support thrust forces in both the positive and negative directions of the X-axis.

[0021] The support part 30 has a tip side bearing 31, a gear shaft bearing 32, a bearing support part 33, a support part housing 34, and a sleeve 36. The support part housing 34 forms an outer shell of the support part 30. The support part housing 34 in this example has an outer contour that is rectangular in plan view and side view. The bearing support part 33 closes the X-axis negative direction side of the support part housing 34.

[0022] The tip side bearing 31 is accommodated in the accommodation recess 332 of the bearing support portion 33 and surrounds the second gear side shaft portion 141 of the pinion shaft 14 to rotatably support the second gear side shaft portion 141. There is no limitation on the configuration of the tip side bearing 31, but the tip side bearing 31 in this example is a cylindrical roller bearing that receives only radial forces. The bearing that receives only radial forces is not limited to a cylindrical roller bearing, and other bearings such as a ball bearing without a flange may be used. Furthermore, the tip side bearing 31 may be a type of bearing other than a bearing that receives only radial forces, such as a deep groove ball bearing or a tapered roller bearing.

[0023] The gear shaft bearing 32 is accommodated in an accommodating recess 342 of the support housing 34, and surrounds the gear shaft 24 at the end position of the support 30 in the positive direction of the Y axis. The gear shaft bearing 32 supports the support 30 rotatably relative to the gear shaft 24. The gear shaft bearing 32 is disposed on the opposite side to the second gear 22 across an extension line of the rotation axis La of the pinion shaft 14. There is no limitation on the configuration of the gear shaft bearing 32, but the gear shaft bearing 32 in this example is a ball bearing. The gear shaft bearing 32 may be a type of bearing other than a ball bearing, such as a cylindrical roller bearing. The inner diameter of the gear shaft bearing 32 is larger than the inner diameter of the tip side bearing 31.

[0024] The sleeve 36 is a hollow cylindrical member that surrounds the gear shaft 24, and is fixed to the support portion housing 34. The support portion 30 is supported by the gear shaft bearing 32 and the sleeve 36 so as to be rotatable relative to the gear shaft 24.

[0025] The gear shaft 24 has a cylindrical shape including a first portion 241 located on the positive side of the Y axis relative to the second gear 22 and a second portion 242 located on the negative side of the Y axis relative to the second gear 22. The first portion 241 is surrounded by the sleeve 36 and the gear shaft bearing 32 of the support portion 30.

[0026] The gear shaft 24 has a first portion 241 and a second portion 242 supported by bearings (not shown), and the second gear 22 is supported by a double-support structure.

[0027] An example of the operation of the gear device 100 of this embodiment configured as above will be described. For example, when the rotation of an external power source (not shown) is input to the pinion shaft 14, the first gear 12 rotates integrally with the pinion shaft 14. When the first gear 12 rotates, the second gear 22 meshing with the first gear 12 and the gear shaft 24 rotate integrally. In other words, the rotation input to the pinion shaft 14 is transmitted via the first gear 12 and the second gear 22 and output from the gear shaft 24.

[0028] When the gear shaft 24 rotates, the support part 30 does not move at a position supporting the second gear side shaft part 141. As a result, the pinion shaft 14 is supported at both ends by the pinion shaft bearings 15, 16, 18 and the tip side bearing 31. When a load is applied to the gear shaft 24, a force in the deviation direction (in this example, the Z-axis direction) is applied to the second gear side shaft part 141 due to the meshing force of the first gear 12 and the second gear 22, which are bevel gears. At this time, the support part 30 supports the second gear side shaft part 141 to suppress the amount of deviation of the second gear side shaft part 141.

[0029] The features of the gear device 100 of this embodiment configured as above will be described. The gear device 100 is a gear device having a first gear 12, a pinion shaft 14 supporting the first gear 12, a second gear 22 meshing with the first gear 12, and a gear shaft 24 supporting the second gear 22 and rotating about a rotation axis Lb that is perpendicular or twisted relative to the rotation axis La of the pinion shaft 14, and has a support portion 30 supporting the second gear 22 side of the pinion shaft 14, and the support portion 30 is supported by the gear shaft 24.

[0030] According to this configuration, since the support portion 30 supports the second gear side shaft portion 141, the amount of deviation of the second gear side shaft portion 141 can be reduced. This reduces misalignment caused by deviation and fluctuations in the tooth contact positions between the gears. As a result, the occurrence of tooth contact abnormalities such as one-sided contact can be suppressed. In addition, the configuration for supporting the pinion shaft 14 at both ends is simple, and design constraints on the support portion 30 are reduced.

[0031] In this embodiment, the pinion shaft bearings 15, 16, and 18, which have a second gear side shaft portion 141 supported by the support portion 30 and an anti-second gear side shaft portion 142 located on the opposite side of the first gear 12 from the second gear side shaft portion, and which support the anti-second gear side shaft portion 142, are bearings that receive thrust forces in both directions. In this case, the meshing force of the first gear 12 and the second gear 22 can reduce the effect of the thrust force acting on the pinion shaft 14.

[0032] In this embodiment, the second gear side shaft portion 141 has a smaller diameter than the anti-second gear side shaft portion 142. In this case, large bearings with large bearing capacity can be used as the pinion shaft bearings 15, 16, 18 supporting the anti-second gear side shaft portion 142, and a small bearing advantageous in space saving can be used as the tip side bearing 31 supporting the second gear side shaft portion 141. This reduces design constraints on the support portion 30.

[0033] In this embodiment, the tip side bearing 31 that supports the second gear side shaft portion 141 is a bearing that receives only radial forces. In this case, since it does not receive thrust forces, a small bearing that is advantageous for saving space can be used as the tip side bearing 31, and design constraints on the support portion 30 are reduced.

[0034] In this embodiment, the support part 30 is supported by the gear shaft 24 via a gear shaft bearing 32, and the gear shaft bearing 32 is disposed on the opposite side to the second gear 22 across an extension line of the rotation axis La of the pinion shaft 14. In this case, there is more space for disposing the tip side bearing 31 than in a configuration in which the gear shaft bearing 32 is disposed closer to the second gear 22, and design constraints on the support part 30 are reduced.

[0035] [Second embodiment] The configuration of a gear device 100 according to the second embodiment will be described with reference to Figures 3 and 4. Figure 3 is a side view of the gear device 100. This figure omits the illustration of the drive gear 28, the driven gear 48, the second base plate 42, etc. Figure 4 is a plan view of the gear device 100. The gear device 100 of this embodiment differs from the first embodiment in that it includes a second stage shaft portion 40, but the other configurations are similar. Therefore, redundant explanations will be omitted and the description will focus on the configurations that differ from the first embodiment.

[0036] The second stage shaft portion 40 has a driven shaft 44 to which rotation is transmitted from the gear shaft 24 of the first stage shaft portion 20 via the drive gear 28 and the driven gear 48. In other words, the gear shaft 24 is a first stage shaft, and the driven shaft 44 is a second stage shaft. The rotation axis Lc of the driven shaft 44 extends parallel to the rotation axis Lb of the gear shaft 24.

[0037] The gear device 100 of this embodiment includes a first base plate 41, a second base plate 42, gear shaft bearings 26, 27, and driven shaft bearings 46, 47. The first base plate 41 and the second base plate 42 are thick plate members extending in the XZ directions and face each other in the Y axis direction with the support part 30 in between. The first base plate 41 and the second base plate 42 function as bases that support both ends of the gear shaft 24 and the driven shaft 44 via the gear shaft bearings 26, 27 and the driven shaft bearings 46, 47.

[0038] The gear shaft bearings 26, 27 support the gear shaft 24 on both axial sides of the gear shaft 24. The gear shaft bearings 26, 27 are received in the receiving recess 412 of the first base plate 41 and the receiving recess 422 of the second base plate .

[0039] The driven shaft bearings 46, 47 support the driven shaft 44 on both axial sides of the driven shaft 44. The driven shaft bearings 46, 47 are received in the accommodating recess 413 of the first base plate 41 and the accommodating recess 423 of the second base plate 42.

[0040] There is no limitation to the configuration of the gear shaft bearings 26, 27 and the driven shaft bearings 46, 47, but in this example they are tapered roller bearings. In this case, rigidity in the radial and thrust directions can be ensured, so misalignment caused by meshing forces can be reduced.

[0041] There is no limitation on the configuration of the drive gear 28 and driven gear 48, but in this example they are intermeshing helical gears.

[0042] An example of the operation of the gear device 100 of this embodiment configured as above will be described. The operation in which the rotation input to the pinion shaft 14 is output from the gear shaft 24 via the first gear 12 and the second gear 22 is the same as in the first embodiment. The rotation transmitted to the gear shaft 24 is transmitted via the drive gear 28 and the driven gear 48, and output from the driven shaft 44. In other words, the rotation input to the pinion shaft 14 is output from the driven shaft 44 after being shifted in two stages.

[0043] According to this embodiment, the same actions and effects as those of the first embodiment are achieved.

[0044] The above describes in detail the examples of the embodiments of the present invention. The above-mentioned embodiments are merely examples of the implementation of the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as changes, additions, and deletions of components are possible within the scope of the invention as defined in the claims. In the above-mentioned embodiments, the contents for which such design changes are possible are described with notations such as "in the embodiment" and "in the embodiment", but this does not mean that design changes are not permitted for contents without such notations. In addition, hatching on the cross sections of the drawings does not limit the material of the objects to which the hatching is applied.

[0045] The following describes the modified examples. In the drawings and description of the modified examples, the same or equivalent components and members as those in the embodiment are denoted by the same reference numerals. Descriptions that overlap with the embodiment will be omitted as appropriate, and the description will focus on configurations that differ from the embodiment.

[0046] In the description of the embodiment, an example was given in which the first gear 12 and the second gear 22 are bevel gears, but this is not limiting. The gear mechanism consisting of the first gear and the second gear may be any gear mechanism supported by a gear shaft and a pinion shaft that rotate around rotation axes that are perpendicular to each other or twisted relative to each other. An example of such a gear mechanism is a hypoid gear in which one shaft is positioned at a position offset from a position perpendicular to the axial direction of the other shaft.

[0047] In the explanation of the second embodiment, an example was shown in which a two-stage speed change shaft, that is, a first-stage shaft and a second-stage shaft, is provided, but the number of stages of the speed change shaft may be three or more.

[0048] Each of the above-described modified examples provides the same functions and effects as the embodiment.

[0049] Any combination of the components and modifications of the above-described embodiments is also useful as an embodiment of the present invention. A new embodiment resulting from the combination has the combined effects of the respective embodiments and modifications. [Explanation of symbols]

[0050] 12 first gear, 14 pinion shaft, 22 second gear, 24 gear shaft, 26 gear shaft bearing, 30 support portion, 31 tip side bearing, 32 gear shaft bearing, 33 bearing support portion, 100 gear device, 141 second gear side shaft portion, 142 anti-second gear side shaft portion.

Claims

1. A gear device including a first gear, a pinion shaft supporting the first gear, a second gear meshing with the first gear, and a gear shaft supporting the second gear and rotating about a rotation axis that is perpendicular or twisted with respect to a rotation axis of the pinion shaft, a support portion for supporting the second gear side of the pinion shaft, The support portion is supported by the gear shaft, The gear shaft is supported by a gear shaft support portion, The second gear side of the pinion shaft is supported by the gear shaft support portion only via the gear shaft. Gear mechanism.

2. the pinion shaft has a second gear side shaft portion supported by the support portion, and an anti-second gear side shaft portion located on the opposite side to the second gear side shaft portion across the first gear, the bearing supporting the shaft portion opposite the second gear is a bearing receiving thrust forces in both directions, The second gear side bearing supporting the second gear side shaft portion is a bearing that receives only radial forces.

2. The gear arrangement of claim 1.

3. The pinion shaft has a second gear side shaft portion supported by the support portion, and an anti-second gear side shaft portion located on the opposite side of the first gear from the second gear side shaft portion, The second gear side shaft portion has a smaller diameter than the gear shaft.

2. The gear arrangement of claim 1.

4. The gear shaft support portion supports both axial sides of the second gear of the gear shaft by the first support portion and the second support portion, The support portion separate from the first support portion and the second support portion is disposed between the first support portion and the second support portion. A gear arrangement according to any one of claims 1 to 3.

5. A gear shaft bearing is provided which surrounds the gear shaft and is supported by the gear shaft; The support portion is supported on the gear shaft via a gear shaft bearing, The gear shaft bearing is disposed on the opposite side to the second gear across an extension line of the rotation axis of the pinion shaft. A gear arrangement according to any one of claims 1 to 4.

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