Assembly

Abstract

An assembly suppresses both deflection of a shaft during high-speed rotation and vibration of the shaft when an additional load of a gear is large. The assembly has: a rotating electric machine; a shaft connected downstream of a rotor of the rotating electrical machine; a gear connected downstream of the shaft; a first bearing provided so as to be able to support the shaft; a second bearing provided so as to be able to support the shaft; and a cushion restricting member provided so as to be able to support the shaft. The rotating electric machine is located between the first bearing and the second bearing in a radial view. The second bearing is located between the gear and the rotating electrical machine in a radial view. The gear is located between the second bearing and the cushion restricting member in a radial view. The buffer restricting member is set such that the allowable amount of movement of the shaft in the radial direction at the corresponding support position is larger than the first bearing and the second bearing.

Description

Technical Field

[0001] This invention relates to a component. Background Technology

[0002] Patent documents 1 and 2 disclose a structure that uses bearings to support the motor shaft at two locations.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-88117

[0006] Patent Document 2: International Publication No. 2019 / 208642

[0007] The technical problem that the invention aims to solve

[0008] When bearings support a shaft at both ends, a long shaft support span (distance between bearings) can lead to increased shaft deflection during high-speed rotation. Conversely, a short shaft support span, causing the gear rotating integrally with the shaft to extend outwards between the two bearings, can cause the shaft to tilt under heavy additional loads, potentially leading to vibration. Summary of the Invention

[0009] The present invention was made in view of the following problems, and its purpose is to suppress both shaft deflection during high-speed rotation and shaft vibration when the additional load of gears is large.

[0010] Technical solutions for solving technical problems

[0011] An embodiment of the present invention comprises: a rotary motor; a shaft downstream of a rotor of the rotary motor; a gear downstream of the shaft; a first bearing configured to support the shaft; a second bearing configured to support the shaft; and a cushioning limiting member configured to support the shaft. In a radial view, the rotary motor is located between the first bearing and the second bearing. In a radial view, the second bearing is located between the gear and the rotary motor. In a radial view, the gear is located between the second bearing and the cushioning limiting member. The cushioning limiting member is configured such that, compared to the first bearing and the second bearing, the allowable radial movement of the shaft at a corresponding support position is greater.

[0012] Invention Effects

[0013] According to this method, considering that a shorter shaft support span reduces the amount of deflection during high-speed shaft rotation, the second bearing is positioned closer to the rotary motor than the gear. Therefore, compared to the arrangement of the rotary motor, gear, and second bearing in that order, the shaft support span between the first and second bearings can be shortened, suppressing shaft deflection during high-speed rotation. On the other hand, if the second bearing is positioned closer to the rotary motor than the gear, the shaft may tilt around the second bearing as a fulcrum when the additional load on the gear increases, resulting in increased shaft vibration. In contrast, the buffer limiting member is configured such that the allowable radial movement of the shaft at the corresponding support position is larger than that of the first and second bearings. Therefore, when the additional load on the gear increases and the shaft tends to tilt, the buffer limiting member can suppress the tilting of the shaft and reduce its amount. Consequently, shaft vibration can also be suppressed when the additional load on the gear is large. Attached Figure Description

[0014] Figure 1 This is a schematic structural diagram of the components in this embodiment.

[0015] Figure 2 This is a diagram showing the assembly viewed from the deceleration mechanism side with the second cover removed.

[0016] Figure 3 This is a diagram showing the peripheral portion of the end of the rotating shaft viewed along the axial direction.

[0017] Figure 4 This is a diagram showing a first variation of the buffer limiting component.

[0018] Figure 5 This is a diagram showing a second variation of the buffer limiting component. Detailed Implementation

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic structural diagram of component 100 in this embodiment. Figure 2 This is a diagram of component 100 viewed from the deceleration mechanism 30 side with the second cover 12 removed. Figure 1 This is an unfolded cross-sectional view of component 100, in which the first axis AX1, the second axis AX2, the third axis AX3, and the fourth axis AX4 of component 100 are contained in the same plane. Figure 2 The vertical direction corresponds to the direction of gravity.

[0021] Regarding the terminology of components, a component can also be referred to as an electric motor assembly (at least an assembly having an electric motor) or a power transmission device (at least a device having a power transmission mechanism). An electric motor is a rotating electrical machine that has the function of an electric motor and / or a generator (at least one of the functions of an electric motor and a generator). A power transmission mechanism is, for example, a gear mechanism and / or a differential gear mechanism. A device (assembly) having an electric motor and a power transmission mechanism is included in both the concepts of electric motor assembly and power transmission device.

[0022] like Figure 1 As shown, component 100 includes a housing 10, a rotary motor 20, a reduction gear 30, and a differential gear 40. Component 100 is mounted on a vehicle. The vehicle is an electric vehicle driven by the rotary motor 20. The housing 10 has a first cover 11, a second cover 12, and a housing 13. The rotary motor 20, the reduction gear 30, and the differential gear 40 are housed within the housing 10. The first cover 11 is located from one axial side ( Figure 1 The opening of the cylindrical housing 13 is closed from the left side, and the opening of the housing 13 is closed from the other side axially. The rotary motor 20 is housed inside the housing 13, and the differential gear 40 is housed inside the second cover 12.

[0023] The rotary electric motor 20 includes a rotor 21, a stator 22, and a rotating shaft 23. The rotor 21 is disposed on the outer periphery of the rotating shaft 23. The stator 22 is disposed in a housing 13 and houses the rotor 21. The rotating shaft 23 is a shaft that protrudes axially from the rotor 21 to both sides. The rotating shaft 23 is connected downstream of the rotor 21. The rotating shaft 23 is connected downstream of the rotor 21 by protruding downstream from the rotor 21. The downstream side is the power output side, and the rotating shaft 23 protrudes axially from the rotor 21 to the other side, thus protruding downstream. The upstream side is the power input side. The connection can also be via other structures (e.g., a clutch, other gear mechanisms). The rotating shaft 23 is connected downstream of the rotor 21 in a manner capable of transmitting power and rotates integrally with the rotor 21.

[0024] The rotating shaft 23 passes through the first cover 11 on one axial side and through the housing 13 on the other axial side. A bearing 51, serving as a first bearing, is provided in the portion of the first cover 11 through which the rotating shaft 23 passes, and a bearing 52, serving as a second bearing, is provided in the portion of the housing 13 through which the rotating shaft 23 passes. The rotating shaft 23 is supported by the bearings 51 and 52. A separator 80 is provided in the portion of the rotating shaft 23 protruding from the first cover 11. The separator 80 detects the rotation of the rotary motor 20.

[0025] Bearing 51 is disposed in a first cover 11, which serves as a bearing retainer, and has a radial clearance. Similarly, bearing 52 is disposed in a housing 13, which serves as a bearing retainer, and has a radial clearance. Bearings 51 and 52 support the rotating shaft 23 near both sides of the rotor 21 in the extending direction of the rotating shaft 23.

[0026] The reduction mechanism 30 is a gear mechanism, comprising a first gear 31, a second gear 32, a third gear 33, a fourth gear 34, a fifth gear 35, a sixth gear 36, a shaft 37, and a shaft 38. The first gear 31 is mounted on the first shaft AX1 together with the rotary motor 20. In other words, the rotary motor 20 and the first gear 31 are coaxially arranged relative to the first shaft AX1. That is, the case where multiple elements (components, parts, etc.) are arranged on the Nth axis (N is a natural number) is synonymous with the case where multiple elements are coaxially arranged relative to the Nth axis. Similarly, the second gear 32 and the third gear 33 are arranged on the second shaft AX2, and the fourth gear 34 and the fifth gear 35 are arranged on the third shaft AX3. The sixth gear 36 and the differential gear 40 are arranged on the fourth shaft.

[0027] The first shaft AX1, the second shaft AX2, the third shaft AX3, and the fourth shaft AX4 all constitute the shafts of assembly 100 and extend in the same direction. Therefore, the extending directions of the first shaft AX1, the second shaft AX2, the third shaft AX3, and the fourth shaft AX4 are all equivalent to the axial direction of assembly 100. That is, the axial direction refers to the axial direction of the rotation axis of the component constituting the assembly (e.g., a motor, a gear mechanism, or a differential gear mechanism). The radial direction of assembly 100 is set to be orthogonal to any one of the first shaft AX1, the second shaft AX2, the third shaft AX3, and the fourth shaft AX4. The first shaft AX1 constitutes the axis of rotation shaft 23, the second shaft AX2 constitutes the axis of shaft 37, the third shaft AX3 constitutes the axis of shaft 38, and the fourth shaft AX4 constitutes the axis of differential gear 40.

[0028] The first gear 31 is connected downstream of the rotating shaft 23. The first gear 31 is positioned on the rotating shaft 23 at a location on the opposite side of the rotor 21 along the axial direction, thus connecting downstream of the rotating shaft 23. The first gear 31 is connected downstream of the rotating shaft 23 in a manner capable of transmitting power. The first gear 31 is located on the rotating shaft 23 at a portion protruding from the housing 13. The first gear 31 is positioned on the rotating shaft 23 in a state of cantilevering outwards (on the opposite side of the axial direction) between bearings 51 and 52. The first gear 31 becomes integral with the rotating shaft 23 by being pressed into it and rotates integrally with the rotating shaft 23. The first gear 31 can also be connected to the rotating shaft 23, for example, by spline engagement. The same applies to the second gear 32, etc.

[0029] The rotating shaft 23 extends axially to the opposite side from the first gear 31. The portion of the rotating shaft 23 extending axially further than the first gear 31 is supported by a bearing 53, which serves as a third bearing. The bearing 53 supports the axially opposite end 23a of the rotating shaft 23. The bearing 53 is disposed in a radially clearance-free state within a second cover 12, which serves as a bearing retainer. The bearing 53 is disposed adjacent to the first gear 31 from the axially opposite side.

[0030] The second gear 32 meshes with the first gear 31. The second gear 32 has more teeth than the first gear 31, and together with the first gear 31, they form the first reduction gear stage. The second gear 32 is mounted on the shaft 37 and is disposed on the second shaft AX2. The second gear 32 is integrally formed with the shaft 37. The shaft 37 extends along the rotation shaft 23. The shaft 37 is supported by a bearing 54 disposed on the housing 13 and a bearing 55 disposed on the second cover 12. The bearings 54 and 55 are disposed at both ends of the shaft 37.

[0031] The third gear 33 is connected downstream of the second gear 32. The third gear 33 is mounted on the shaft 37 and disposed on the second shaft AX2. The third gear 33 is located on the shaft 37 in a direction that extends away from the rotary motor 20 than the second gear 32, i.e., on the other side of the axial direction. The third gear 33 is integrally formed with the shaft 37. The second gear 32 and the third gear 33 are axially disposed between the bearings 54 and 55.

[0032] The fourth gear 34 meshes with the third gear 33. The fourth gear 34 has more teeth than the third gear 33, and together they form the second reduction gear stage. The fourth gear 34 is mounted on the shaft 38 and is disposed on the third shaft AX3. The fourth gear 34 is integrally formed with the shaft 38. The shaft 38 extends along the rotation shaft 23. The shaft 38 is supported by a bearing 56 disposed on the housing 13 and a bearing 57 disposed on the second cover 12. The bearings 56 and 57 are disposed at both ends of the shaft 38.

[0033] The fifth gear 35 is downstream of the fourth gear 34. The fifth gear 35 is mounted on shaft 38, which is disposed on the third shaft AX3. The fifth gear 35 is located on a portion of shaft 38 extending axially towards the rotary motor 20, closer to the fourth gear 34. Therefore, in shaft 38, the power transmission direction is reversed axially relative to shaft 37. The fifth gear 35 is integrally formed with shaft 38. The fourth gear 34 and the fifth gear 35 are axially disposed between bearings 56 and 57.

[0034] The sixth gear 36 meshes with the fifth gear 35. The sixth gear 36 is the end-drive gear and is located on the differential gear 40. The sixth gear 36 and the differential gear 40 are configured together on the fourth shaft AX4. Power from the rotary motor 20 is transmitted from the sixth gear 36 to the differential gear 40. Therefore, the differential gear 40 is downstream of the sixth gear 36.

[0035] The sixth gear 36 overlaps with the first gear 31 when viewed radially. In other words, the first gear 31 has a portion that overlaps with the sixth gear 36 when viewed radially. This portion overlaps with the sixth gear 36, for example, when viewed radially along a plane including the first axis AX1 and the fourth axis AX4. Overlapping in a predetermined direction, including radial and axial views, means overlapping in that predetermined direction, implying that multiple elements are arranged in that predetermined direction. Therefore, when multiple elements are illustrated in the accompanying drawings as arranged in a predetermined direction, it can be considered that the specification includes an explanation of the overlap of multiple elements when viewed in the predetermined direction.

[0036] The sixth gear 36 has more teeth than the fifth gear 35, and together with the fifth gear 35, they form the third reduction gear stage. Therefore, in the reduction mechanism 30, three-stage reduction is achieved through the first gear 31 and the second gear 32, the third gear 33 and the fourth gear 34, and the fifth gear 35 and the sixth gear 36.

[0037] The differential gear 40 is a differential gear mechanism, comprising a differential housing 41 and a differential section 42. The differential housing 41 is supported by a bearing 58 located on the housing 13 and a bearing 59 located on the second cover 12, and rotates integrally with the sixth gear 36. The sixth gear 36 is coaxially fixed to the outer wall of the differential housing 41, and the differential housing 41 houses the differential section 42. The differential section 42 distributes and outputs the power input to the differential housing 41 via the sixth gear 36 to the drive wheels in the left and right directions of the vehicle.

[0038] The differential gear 40 protrudes away from the stator 22 relative to the sixth gear 36. The differential gear 40 protrudes as a portion that protrudes further axially from the sixth gear 36. In other words, the differential gear 40 protrudes further away from the stator 22 relative to the sixth gear 36 than it would be closer to the stator 22, and is positioned near the stator 22 relative to the sixth gear 36.

[0039] A first drive shaft 61 is assembled on one axial side of the differential section 42, and a second drive shaft 62 is assembled on the other axial side. Power from the rotary motor 20 is transmitted from the differential section 42 to one drive wheel via the first drive shaft 61, and to the other drive wheel via the second drive shaft 62. The first drive shaft 61 is longer than the second drive shaft 62, thereby allowing for a sufficient distance between the drive wheel and the differential gear 40, thus suppressing bends. The first drive shaft 61 is supported by a bearing 60 provided in the first cover 11.

[0040] The sixth gear 36 can also be understood as part of the differential gear 40. That is, the sixth gear 36 can also be understood as a component of the differential gear 40. In this case, it can also be understood that the differential gear 40 is connected to the downstream of the sixth gear 36 in such a way that a part of the differential gear 40, which includes a differential section 42 that outputs power from the rotary motor 20, is connected to the downstream of the sixth gear 36.

[0041] like Figure 2 As shown, the first axis AX1 and the fourth axis AX4 are positioned below the second axis AX2 and the third axis AX3 when viewed axially. "Above" and "below" refer to the vertical relationship in the direction of gravity when viewed in a specified direction, including axial and radial views; both include "above" and "below".

[0042] "Above" and "below" refer to configurations that appear to overlap in the direction of gravity when viewed in a specified direction, including axial and radial views. For example, if a first element and a second element overlap in the direction of gravity when viewed axially, and the first element is positioned higher than the second element, then the first element is positioned above the second element. In this case, when viewed radially, the first and second elements may either overlap or be offset.

[0043] In addition to above and below, the upper side and lower side also include the positional relationship of being obliquely above and obliquely below when viewed in a specified direction including axial and radial views. Therefore, for example, when viewed axially, the first element is located obliquely above the second element in a state where it does not overlap with the second element in the direction of gravity, and when viewed radially, the first element is located on the upper side of the second element where the first element and the second element do not overlap.

[0044] As a result of the configuration described above, the first axis AX1 and the fourth axis AX4 are arranged in a layout that is concentrated on the lower side of the component 100 in the direction of gravity. Furthermore, since the rotary motor 20, which is mounted on the first axis AX1, is positioned on the lower side in the direction of gravity, space can be provided above the rotary motor 20. The first axis AX1 is positioned above the fourth axis AX4.

[0045] The bearing 53 has a metal inner ring 53a, rolling elements 53b, and outer ring 53c. When the bearing 53 supports the rotating shaft 23, the bearing 53 is supported by the second cover 12 while supporting the rotating shaft 23, with the inner ring 53a, rolling elements 53b, and outer ring 53c in close radial contact with each other. The bearing 51 provided in the first cover 11 and the bearing 52 provided in the housing 13 are similar.

[0046] return Figure 1 The rotary motor 20 is located between bearings 51 and 52 when viewed radially. Bearing 52 is located between the first gear 31 and the rotary motor 20 when viewed radially. The first gear 31 is located between bearings 52 and 53 when viewed radially.

[0047] The shorter the shaft support span, the less deflection occurs when the rotating shaft 23 rotates at high speed. Conversely, the bearing 52 is positioned closer to the rotary motor 20 than the first gear 31. Therefore, compared to the arrangement of the rotary motor 20, first gear 31, and bearing 52, the shaft support span of bearings 51 and 52 can be shortened, thus suppressing deflection of the rotating shaft 23 during high-speed rotation.

[0048] On the other hand, if the bearing 52 is positioned closer to the rotary motor 20 than the first gear 31, the rotation shaft 23 may tilt with the bearing 52 as the fulcrum when the additional load on the first gear 31 increases, and the vibration of the rotation shaft 23 may increase.

[0049] In contrast, bearing 53 is configured such that the allowable radial movement of the rotating shaft 23 at the corresponding support position is larger than that of bearings 51 and 52. The allowable radial movement refers to the maximum radial movement of a specified component, and the allowable radial movement of the rotating shaft 23 at the support position of bearing 53 can be set based on the allowable radial movement of bearing 53. Furthermore, the allowable radial movement of bearing 53 can be set to be larger than that of bearings 51 and 52 by placing bearing 53 in the second cover 12 with a looser fit than bearing 51 in the first cover 11 and bearing 52 in the housing 13.

[0050] Therefore, when the additional load on the first gear 31 increases and the rotating shaft 23 tends to tilt, the bearing 53 suppresses the tilt of the rotating shaft 23 and reduces its tilt amount. As a result, the vibration of the rotating shaft 23 is also suppressed when the additional load on the first gear 31 is large.

[0051] Furthermore, with the rotating shaft 23 supported by bearings 51 and 52, bearing 53 becomes a state with so-called clearance. On the other hand, for example, if the rotating shaft 23 is constantly constrained by the three components of bearing 51, bearing 52, and certain support members, vibration can be consistently reduced, but this requires very high dimensional accuracy in the design of the components. Therefore, by using bearing 53, whose radial allowable movement is set to be larger than that of bearings 51 and 52, there is also a aspect that can reduce the design difficulty.

[0052] Bearing 53, while supported by bearings 51 and 52 on the rotating shaft 23, has clearance, meaning it cannot be said to truly support the rotating shaft 23. Therefore, it can be said that bearing 53 is configured to support the rotating shaft 23. Regarding bearings 51 and 52, for example, they have a radial allowable movement due to a relaxed fit, meaning that when the rotating shaft 23 vibrates, it may not be said to support the rotating shaft 23 based on vibration; therefore, it can be said that they are configured to support the rotating shaft 23. That is, being configured to support the rotating shaft 23 can be said to have clearance (radial allowable movement).

[0053] The rotating shaft 23 is composed of a single component. In the case that the rotating shaft 23 is a single component, the bearings 51, 52 and 53 supporting the rotating shaft 23 can suppress both the deflection of the rotating shaft 23 when it rotates at high speed and the vibration of the rotating shaft 23 when the additional load of the first gear 31 is large.

[0054] Furthermore, regarding shafts that are single components, such as shafts composed of multiple splined shafts, vibrations are absorbed by the backlash in the splined engagement. From a vibration perspective, they cannot be considered as a single component and are therefore not shafts that are single components. On the other hand, even if a shaft is composed of multiple splined shafts, when they are fully and tightly fitted together, a shaft composed of multiple welded shafts is considered as a single component because there is no backlash between the shafts. Therefore, it is a shaft that is a single component.

[0055] Bearings 51, 52, and 53 have bearing clearances CL. Regarding bearing 53, the bearing clearance CL includes, in addition to the radial clearance between the second cover 12 and bearing 53 (i.e., the first bearing clearance), the radial clearances formed between the inner ring 53a and rolling element 53b of bearing 53 and between the rolling element 53b and outer ring 53c of bearing 53 (i.e., the second bearing clearance), and the radial clearance formed between the rotating shaft 23 and the inner ring 53a of bearing 53 (i.e., the third bearing clearance). Bearings 51 and 52 are similar.

[0056] exist Figure 1 , Figure 3In the diagram, the bearing clearance CL of bearing 53 represents the first bearing clearance between the second cover 12 and bearing 53. Figure 3 This is a view of the periphery of the end 23a of the rotating shaft 23 viewed along the axial direction from the other side of the axial direction. Figure 3 In the diagram, when bearing 53 is tilted downwards due to the inclination of rotating shaft 23, the bearing clearance CL is indicated. Figure 3 In the diagram, the maximum extent of the bearing clearance CL is indicated by a symbol. Additionally, in... Figure 1 , Figure 3 For ease of explanation, the bearing clearance CL is depicted in an exaggerated manner. Such a bearing clearance CL can be provided, for example, by pressing the bearing 53 into and fixing it to the rotating shaft 23. On the other hand, if the bearing 53 is pressed into and fixed to the second cover 12, etc., a bearing clearance CL (third bearing clearance) can also be provided between the rotating shaft 23 and the inner ring 53a.

[0057] The bearing clearance CL of bearing 53 is set to be larger than the bearing clearance CL of bearings 51 and 52, and the allowable radial movement can be set according to the bearing clearance CL. Therefore, if the bearing clearance CL of bearing 53 is set as described above, the allowable radial movement can be adjusted by setting the bearing clearance CL. The bearing clearance CL of bearings 51 and 52 can also both be zero.

[0058] Furthermore, there is no correlation between the bearing clearance CL and the bearing diameter. For example, when the bearing diameters are equal, the bearing clearance CL can be adjusted by changing the size of the rolling elements. Additionally, even when the bearing diameters are different, the bearing clearance CL can still be adjusted by changing the size of the rolling elements. Therefore, for example, it is possible to make the bearing clearance CL of the bearing with the smaller diameter larger than that of the bearing with the larger diameter, or vice versa.

[0059] Bearing 53 is a limiting component, equivalent to a buffer limiting component. A buffer limiting component includes at least one of a buffer component that buffers the radial movement of the rotating shaft 23 at its support position and a limiting component that restricts (limits) the radial movement of the rotating shaft 23 at its support position. The buffer limiting component can be both a buffer component and a limiting component. Bearing 53 has clearance when the rotating shaft 23 is supported by bearings 51 and 52. On the other hand, when the additional load on the first gear 31 increases and the rotating shaft 23 tilts, bearing 53 itself is radially positioned between the rotating shaft 23 and the second housing 12, thereby limiting the movement of the rotating shaft 23 beyond the permissible radial movement, thus suppressing the tilting of the rotating shaft 23, and thus functioning as a limiting component.

[0060] The bearing 53, consisting of an inner ring 53a, rolling elements 53b, and outer ring 53c that are radially tightly fitted together when subjected to load, is made of metal and can elastically deform within its elastic deformation range; therefore, it can also be considered a buffer component. Regarding the bearing 53, its function of limiting movement is more important than its buffering effect based on the elastic deformation of the metal; therefore, in this embodiment, the bearing 53 is considered a limiting component. Alternatively, a buffer device 70, as described below, can be used instead of the bearing 53 as a buffer limiting component.

[0061] Figure 4 This is a diagram showing a first variation of the buffer limiting component. Figure 4 This is a view of the periphery of the end 23a of the rotating shaft 23, viewed from the other side along the axial direction. The buffer device 70 has a buffer spring 71 as an elastic body, a ball 72 subjected to force by the buffer spring 71, and a main body 73 that houses the buffer spring 71 and the ball 72. The main body 73 may be composed of multiple parts.

[0062] A buffer device 70 is provided on the second cover 12. The buffer device 70 is arranged such that the extension and retraction direction of the buffer spring 71 is along the radial direction of the rotation shaft 23, and the ball bearing 72 is arranged such that it is separated from and opposite to the outer peripheral surface of the rotation shaft 23.

[0063] The main body 73 has a bottomed cylindrical shape. A buffer spring 71 is disposed inside the main body 73 between the bottom of the main body 73 and the ball 72. The front opening of the main body 73 has a diameter smaller than the outer diameter of the ball 72, and the ball 72 partially protrudes from this front opening when the buffer spring 71 applies force. The ball 72 is separate from and opposite the outer peripheral surface of the end 23a of the rotating shaft 23. Furthermore, in Figure 4 For ease of explanation, the gap between the ball bearing 72 and the rotating shaft 23 is exaggerated. Multiple buffer devices 70 are evenly distributed (four in this case) around the rotating shaft 23.

[0064] In this example, when the rotating shaft 23 is tilted with the bearing 52 as the fulcrum, the rotating shaft 23 comes into contact with the ball 72. Furthermore, when the rotating shaft 23 compresses the buffer spring 71 via the ball 72, the energy of the rotating shaft 23, which is about to move radially, is absorbed by the buffer spring 71. As a result, the buffer device 70 functions as a buffer component, suppressing vibration.

[0065] With the buffer spring 71 compressed, the rotating shaft 23 is temporarily supported by the buffer device 70. Therefore, in this example, the buffer device 70 is configured such that the allowable radial movement of the rotating shaft 23 at the corresponding support position is larger than that of the bearings 52 and 53. In other words, the allowable radial movement of the rotating shaft 23 at the support position of the buffer device 70 is the allowable radial movement of the portion of the rotating shaft 23 supported by the buffer device 70 (i.e., end 23a). This allowable movement can be appropriately set based on the arrangement of the buffer device 70 along the radial direction of the rotating shaft 23, the stroke (protrusion) of the ball bearing 72, etc., in addition to the elastic force of the buffer spring 71. In this example, the allowable radial movement can be adjusted by adjusting the elastic force of the buffer device 70 (the elastic force of the buffer spring 71), which is a spring component.

[0066] The buffer device 70 is a buffer component, equivalent to a buffer limiting component. As a buffer component, an elastic component with elasticity can be used. The elastic component is, for example, composed of an elastic body such as a spring or rubber. Therefore, in addition to components with elasticity, there are components like the buffer device 70 that have elasticity through a portion exerting elasticity by an elastic body; and components that have elasticity through a portion exerting elasticity by a fluid (gas, liquid), including a fluid pressure damper such as an air damper or an oil damper. The elastic component is a component that, as a displacement for exerting elasticity (elastic displacement, stroke of the fluid pressure damper), has a displacement larger than that of a metal material. Alternatively, the elastic component is a component that, as a displacement for exerting elasticity, has a displacement larger than that of the bearing 53. The same applies when comparing it to bearings 51 and 52.

[0067] The buffer device 70 can also limit the radial movement of the rotating shaft 23 by the elastic force of the buffer spring 71, and therefore can also be called a limiting component. In this embodiment, the buffer device 70 has a buffer spring 71, thus becoming a structure that at least provides buffering (a buffering that has a significant difference in vibration suppression of the rotating shaft 23 compared to the metal or bearing 53 used as raw materials), and therefore the buffer device 70 is regarded as a buffering component.

[0068] Alternatively, the following structure can be used instead of the bearing 53, which serves as a buffer and limiting component.

[0069] Figure 5 This is a diagram showing a second modified example of the buffer limiting component. Figure 5 In, with Figure 3 , Figure 4 Similarly, the peripheral portion of the end 23a of the rotating shaft 23 is also indicated. In this example, rubber 90 is disposed on the radial outer periphery of the bearing 53. The rubber 90 is disposed on the second cover 12 in a manner separate from and opposite to the outer peripheral surface of the bearing 53. Furthermore, in Figure 5For ease of explanation, the gap between the rubber 90 and the outer peripheral surface of the bearing 53 is exaggerated. The rubber 90 is radially disposed between the bearing 53 and the second cover 12, and is arranged in a ring around the bearing 53. Multiple rubbers 90 may also be locally disposed on the radial outer periphery of the bearing 53. In this case, multiple rubbers 90 can be evenly disposed along the circumference of the bearing 53.

[0070] In this example, when the rotating shaft 23 is tilted with the bearing 52 as the fulcrum, the rotating shaft 23 comes into contact with the rubber 90. Furthermore, when the rotating shaft 23 compresses the rubber 90, the energy of the rotating shaft 23, which is attempting to move radially, is absorbed by the rubber 90. As a result, the rubber 90 functions as a cushioning component, suppressing vibration.

[0071] When the rubber 90 is compressed, the rotating shaft 23 is temporarily supported by the rubber 90 via the bearing 53. Therefore, in this example, the rubber 90 is configured such that the allowable radial movement of the rotating shaft 23 at the corresponding support position is larger compared to the bearings 52 and 53. In other words, the allowable radial movement of the rotating shaft 23 at the support position of the rubber 90 is the allowable radial movement of the portion of the rotating shaft 23 supported by the rubber 90 (i.e., end 23a). This allowable movement can be appropriately set based on factors such as the elasticity of the rubber 90 and the thickness of the rubber 90.

[0072] Rubber 90 is a cushioning component; in this example, rubber 90, together with bearing 53, constitutes a cushioning and limiting component. Therefore, when setting the allowable radial movement of the uncovered area by adjusting the bearing clearance CL of bearing 53, the allowable radial movement of the uncovered area can be set by utilizing the elasticity of rubber 90.

[0073] The rubber 90 can also restrict the radial movement of the rotating shaft 23, and therefore can also be called a limiting component. In this embodiment, by making the rubber 90 an elastomer, it becomes a structure that at least provides cushioning (a cushioning that is significantly different in suppressing the vibration of the rotating shaft 23 compared to the metal or bearing 53 used as raw materials), and therefore the rubber 90 is regarded as a cushioning component.

[0074] Furthermore, when bearing 53 and rubber 90 constitute a buffer limiting component, the bearing clearance CL of bearing 53 may or may not be adjusted. That is, in this case, as long as bearing 53 and rubber 90 as a whole ensure the desired allowable radial movement, the adjustment of bearing clearance CL of bearing 53 may not be necessary.

[0075] The rubber 90 may also be disposed on the outer peripheral surface of the bearing 53. Alternatively, the rubber 90 may be disposed on the radial inner periphery (inner periphery) of the bearing 53. In this case, the rubber 90 may be disposed radially between the inner ring 53a and the rolling element 53b, or between the rolling element 53b and the outer ring 53c of the bearing 53. The rubber 90 may be an elastomer containing the rubber 90, or an elastomer other than an elastomer may be used instead of the rubber 90.

[0076] Next, the main effects of this embodiment will be explained.

[0077] (1) Component 100 includes a rotary motor 20, a rotating shaft 23 connected downstream of the rotor 21 of the rotary motor 20, a first gear 31 connected downstream of the rotating shaft 23, a bearing 51 configured to support the rotating shaft 23, a bearing 52 configured to support the rotating shaft 23, and a bearing 53 configured to support the rotating shaft 23 as a buffer limiting member. When viewed radially, the rotary motor 20 is located between the bearings 51 and 52. When viewed radially, the bearing 52 is located between the first gear 31 and the rotary motor 20. When viewed radially, the first gear 31 is located between the bearings 52 and 53. The bearing 53 is configured such that, compared to the bearings 51 and 52, the allowable radial movement of the rotating shaft 23 at the corresponding support position is increased.

[0078] With this structure, bearing 52 is positioned closer to the rotary motor 20 than the first gear 31. Therefore, compared to the arrangement of the rotary motor 20, first gear 31, and bearing 52, the span between the bearings 51 and 52 can be shortened, thereby suppressing deflection of the rotating shaft 23 during high-speed rotation. Furthermore, bearing 53 is configured such that the allowable radial movement of the rotating shaft 23 at its corresponding support position is larger than that of bearings 51 and 52. Therefore, when the additional load on the first gear 31 increases and the rotating shaft 23 tends to tilt, the tilt of the rotating shaft 23 can be suppressed by bearing 53, reducing its tilt amount. Consequently, vibration of the rotating shaft 23 when the additional load on the first gear 31 is large can also be suppressed.

[0079] (2) Component 100 has a bearing 53 as a buffer limiting member, thereby constituting a buffer limiting member including bearing 53. The bearing clearance CL of bearing 53 is set to be larger than the bearing clearance CL of bearings 51 and 52. According to this structure, the allowable radial movement can be adjusted by setting the bearing clearance CL of bearing 53.

[0080] (3) Alternatively, a buffer device 70 may be provided instead of the bearing 53, which serves as a buffer limiting component. The assembly 100 may also be configured to include the buffer device 70 as a spring-loaded component, which serves as a buffer limiting component. With such a structure, the allowable radial movement can be adjusted by adjusting the spring force of the buffer device 70.

[0081] (4) Alternatively, the bearing 53 and rubber 90 can be provided instead of the bearing 53 as a buffer limiting component, and the assembly 100 can also be configured as a buffer limiting component including the bearing 53 and the rubber 90 as an elastic component. In this case, the rubber 90 as an elastic component is disposed on the radial inner circumference or radial outer circumference of the bearing 53.

[0082] Based on this structure, when the allowable radial movement of the uncovered area is set by adjusting the bearing clearance CL of the bearing 53, the allowable radial movement of the uncovered area can be set by utilizing the elasticity of the rubber 90.

[0083] (5) Component 100 includes a rotary motor 20, a rotating shaft 23 connected downstream of the rotor 21 of the rotary motor 20, a first gear 31 connected downstream of the rotating shaft 23, a bearing 51 configured to support the rotating shaft 23, a bearing 52 configured to support the rotating shaft 23, and a bearing 53 configured to support the rotating shaft 23. In radial view, the rotary motor 20 is located between bearings 51 and 52. In radial view, bearing 52 is located between the first gear 31 and the rotary motor 20. In radial view, the first gear 31 is located between bearings 52 and 53. The bearing clearance CL of bearing 53 is set to be larger than the bearing clearance CL of bearings 51 and 52.

[0084] With this structure, bearing 52 is positioned closer to the rotary motor 20 than the first gear 31. Therefore, compared to the arrangement of the rotary motor 20, first gear 31, and bearing 52 in that order, the span between the bearings 51 and 52 can be shortened, suppressing deflection of the rotating shaft 23 during high-speed rotation. Furthermore, the bearing clearance CL of bearing 53 is set to be larger than the bearing clearance CL of bearings 51 and 52. Therefore, when the additional load on the first gear 31 increases and the rotating shaft 23 tends to tilt, the bearing 53 can suppress the tilting of the rotating shaft 23 and reduce its amount of tilt. Consequently, vibration of the rotating shaft 23 can also be suppressed when the additional load on the first gear 31 is large.

[0085] (6) Component 100 includes a rotary motor 20, a rotating shaft 23 connected downstream of the rotor 21 of the rotary motor 20, a first gear 31 connected downstream of the rotating shaft 23, a bearing 51 configured to support the rotating shaft 23, a bearing 52 configured to support the rotating shaft 23, and a bearing 53 configured to support the rotating shaft 23. When viewed radially, the rotary motor 20 is located between bearing 51 and bearing 52. When viewed radially, bearing 52 is located between the first gear 31 and the rotary motor 20. When viewed radially, the first gear 31 is located between bearing 52 and bearing 53. A rubber 90 with elasticity, serving as an elastic member, is disposed on the radial inner or radial outer periphery of bearing 53.

[0086] With this structure, the bearing 52 is positioned closer to the rotary motor 20 than the first gear 31. Therefore, compared to the arrangement of the rotary motor 20, first gear 31, and bearing 52 in that order, the span of the bearing 51 and bearing 52's shaft support can be shortened, suppressing deflection of the rotating shaft 23 during high-speed rotation. Furthermore, rubber 90 is disposed on the radial inner or radial outer circumference of the bearing 53. Therefore, when the additional load on the first gear 31 increases and the rotating shaft 23 tilts, the rubber 90 disposed with the bearing 53 can suppress the tilting of the rotating shaft 23 and reduce its tilting amount. As a result, vibration of the rotating shaft 23 when the additional load on the first gear 31 is large can also be suppressed.

[0087] The embodiments of the present invention have been described above, but the above embodiments only show a part of the application examples of the present invention, and the technical scope of the present invention is not limited to the specific structure of the above embodiments.

[0088] Symbol Explanation

[0089] 20: Rotary motor

[0090] 21: Rotor

[0091] 23: Rotation axis (shaft)

[0092] 31: First Gear (Gear)

[0093] 51: Bearing (First Bearing)

[0094] 52: Bearing (Second Bearing)

[0095] 53: Bearing (buffered restraint component, restraint component, third bearing)

[0096] 70: Buffer device (buffer limiting component, buffer component, elastic component)

[0097] 90: Rubber (cushioning and limiting components, cushioning components, elastic components)

[0098] 100: Components

Claims

1. A component, characterized in that, have: Rotary electric motor; A shaft, which is connected downstream of the rotor of the rotary electric motor; A gear, which is connected downstream of the shaft; A first bearing, configured to support the shaft; A second bearing is configured to support the shaft; A buffer limiting component, configured to support the shaft. When viewed radially, the rotary motor is located between the first bearing and the second bearing. When viewed radially, the second bearing is located between the gear and the rotary motor. When viewed radially, the gear is located between the second bearing and the buffer restraint component. The buffer limiting component is configured such that, compared to the first bearing and the second bearing, the allowable radial movement of the shaft at the corresponding support position is increased.

2. The component according to claim 1, characterized in that, The buffer limiting component includes a third bearing. The bearing clearance of the third bearing is set to be larger than that of the first bearing and the second bearing.

3. The component according to claim 1, characterized in that, The buffer limiting component includes an elastic component with elasticity.

4. The component according to claim 1, characterized in that, The buffer limiting component includes a third bearing and a spring-loaded component. The elastic component is disposed on the radial inner circumference or radial outer circumference of the third bearing.

5. A component, characterized in that, have: Rotary electric motor; A shaft, which is connected downstream of the rotor of the rotary electric motor; A gear, which is connected downstream of the shaft; A first bearing, configured to support the shaft; A second bearing is configured to support the shaft; A third bearing is configured to support the shaft. When viewed radially, the rotary motor is located between the first bearing and the second bearing. When viewed radially, the second bearing is located between the gear and the rotary motor. When viewed radially, the gear is located between the second bearing and the third bearing. The bearing clearance of the third bearing is set to be larger than that of the first bearing and the second bearing.

6. A component, characterized in that, have: Rotary electric motor; A shaft, which is connected downstream of the rotor of the rotary electric motor; A gear, which is connected downstream of the shaft; A first bearing, configured to support the shaft; A second bearing is configured to support the shaft; A third bearing is configured to support the shaft. When viewed radially, the rotary motor is located between the first bearing and the second bearing. When viewed radially, the second bearing is located between the gear and the rotary motor. When viewed radially, the gear is located between the second bearing and the third bearing. A spring-loaded component with elasticity is disposed on the radial inner or radial outer circumference of the third bearing.

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