Sliding bearing device for a rotating shaft of a vehicle drive motor

Abstract

Provided is a sliding bearing device for a rotating shaft of a vehicle drive motor, which is capable of supplying lubricating oil to a sliding surface in a sufficient amount of oil without forced oil supply, is capable of sufficiently cooling the sliding surface and its vicinity, and is capable of suppressing generation of vibration and noise. A metal base (10A) has an opening passage (11) that communicates between an inner peripheral surface (10b) and an outer peripheral surface (10a), a housing (2) has a communication passage (21), an opening portion (21a) of one side of the communication passage (21) communicates with the opening passage (11) of the metal base (10A) on the outer peripheral surface (10a) side, and an opening portion (21b) of the other side opens to the outside or the inside of the housing (2), and further, the opening passage (11) of the metal base (10A) and the communication passage (21) of the housing (2) are disposed in an orientation, position, and size that are optimized with respect to a direction of action of gravity (G).

Description

Technical Field

[0001] This invention relates to a device for supporting the rotating shaft of a vehicle drive motor as a rotatable sliding bearing. Background Technology

[0002] Traditionally, motors that generate rotational power use bearings to support their rotating shafts so that they can rotate. Motors are used to drive various machines, such as vehicles. Examples of such motors include a motor comprising a housing, a stator with coils, a rotor with magnets, a rotating shaft connected to the rotor, and bearings, wherein the bearings are mounted in the housing to support the rotating shaft and are disposed in bearing retaining holes in the housing.

[0003] In the motor described above, the stator is positioned outside the rotating shaft within the housing, and a rotor connected to the rotating shaft is positioned inside the stator. In this structure, when the stator coils are energized, the coils generate a magnetic field. The interaction between this magnetic field and the magnetic field of the rotor magnet causes the rotor to rotate, and consequently, the rotating shaft rotates. Furthermore, by outputting the rotational power of the rotating shaft to the outside, it can be used as a power source to drive the aforementioned vehicles, etc.

[0004] The motor installed in an electric vehicle to drive the vehicle is driven, for example, by an inverter (see, for example, Patent Document 1). As described in Patent Document 1, when the motor is driven by an inverter, the frequency of the power supply energizing the coil is changed, thereby changing the rotational speed of the rotating shaft.

[0005] Furthermore, the vehicle drive motor described in Patent Document 1 is configured such that a rolling bearing is used as a bearing to support a rotating shaft, and oil supplied from the outside is agitated and splashed along with the rotation of the rotating shaft. A portion of the splashed oil reaches the rolling bearing, thereby cooling and lubricating the rolling bearing.

[0006] Furthermore, as a vehicle drive device (vehicle drive motor), a motor with the following structure has been proposed: liquid refrigerant supplied to the axial oil passage of the hollow rotating shaft is ejected from a hole provided radially on the rotating shaft into the motor housing by centrifugal force accompanying the rotation of the rotating shaft (see, for example, Patent Document 2). According to the vehicle drive device described in Patent Document 2, the rotor coils are cooled by the liquid refrigerant supplied to the motor housing. Furthermore, the supplied liquid refrigerant is agitated and splashed due to the rotation of the rotating shaft, and a portion of it reaches the rolling bearings, thereby cooling and lubricating the rolling bearings.

[0007] Furthermore, to reduce vibration and noise generated by bearings in rotating machines, sliding bearings, which are less prone to vibration and have superior quietness compared to rolling bearings, are also used. As such sliding bearings, there are sliding bearings installed in rotating machines, such as steam turbines in power generation equipment (see, for example, Patent Document 3). According to the two-circular-arc bearing lubrication system described in Patent Document 3, an oil passage is formed to supply lubricating oil to the sliding surface. As the rotating shaft rotates, the supplied lubricating oil is positioned within the bearing clearance (oil clearance) between the rotating shaft and the sliding bearing, thereby supporting the rotating shaft to rotate.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2022-146253

[0011] Patent Document 2: Japanese Patent Application Publication No. 2023-64742

[0012] Patent Document 3: Japanese Patent Application Publication No. 2010-216522 Summary of the Invention

[0013] The technical problem that the invention aims to solve

[0014] As disclosed in Patent Documents 1 and 2, the bearings supporting the rotating shaft in vehicle drive motors are generally rolling bearings, and the lubrication of rolling bearings involves supplying lubricating oil from the side between the outer and inner rings. However, rolling bearings are bearing structures that use rolling elements such as balls, so there are concerns about noise. Therefore, from the viewpoint of quietness within the vehicle, it is important to strive for quieter vehicle drive motors. Therefore, similar to various rotating machines used at high speeds, research has been conducted on using sliding bearings, which are less prone to vibration and noise compared to conventional rolling bearings, instead of the rolling bearings used previously.

[0015] Furthermore, vehicle drive motors used in electric vehicles and the like are trending towards smaller size and higher rotation speeds. Therefore, from the perspective of suppressing noise and vibration associated with high-speed rotation, using sliding bearings instead of rolling bearings has significant advantages.

[0016] However, when simply replacing rolling bearings with sliding bearings, the bearing clearance of sliding bearings is very narrow. Therefore, even if oil is supplied from the bearing clearance on the side of the bearing in the same way as rolling bearings, the lubricating oil may have difficulty entering the bearing clearance. In this case, the amount of oil supplied to the bearing clearance is insufficient, making it difficult to obtain adequate cooling. As a result, sintering may occur on the sliding surface, and there may even be a problem of degraded characteristics of the vehicle drive motor.

[0017] Furthermore, when lubricating oil is supplied from the bearing clearance on the side of the sliding bearing using the aforementioned oil supply method, the bearing clearance to which the oil is to be supplied is itself a part from which the lubricating oil is discharged. This results in collisions between the supplied and discharged lubricating oil. Consequently, the exchangeability of the lubricating oil is very low, making it difficult to supply oil at the desired quantity and speed.

[0018] On the other hand, sliding bearings used in various rotating machines at high speeds generate a great deal of heat due to friction, requiring a large amount of lubricating oil. Therefore, there are many cases where forced oil supply methods, such as pressure pumps, are used. In this way, when a structure is used to supply lubricating oil to the sliding surface between the sliding bearing and the rotating shaft via forced oil supply, a sufficient oil supply can be obtained, and the oil film on the sliding surface can be well maintained. Therefore, heat generation on the sliding surface can be suppressed, and sufficient cooling can be achieved. Methods for forcibly supplying lubricating oil to sliding bearings in various rotating machines include, for example, applying oil pressure to oil passages provided in the housing and the sliding bearing to supply lubricating oil, or directly supplying lubricating oil to the sliding surface of the rotating shaft via internal oil passages.

[0019] However, when the above-mentioned structure for forced oil supply to sliding bearings is applied to vehicle drive motors, the following problems arise: such as the increase in the oil passage for delivering lubricating oil to the sliding bearings, and the increase in the size of the pump for pressurizing lubricating oil, which makes the structure more complex and increases the manufacturing cost.

[0020] Therefore, when using sliding bearings in vehicle drive motors to improve quietness and enhance the cooling performance of the sliding surfaces between the rotating shaft and the sliding bearings, there is a strong demand for a method that achieves sufficient oil supply with a simple structure.

[0021] The present invention was developed in view of the above-mentioned problems, and aims to provide a sliding bearing device for the rotating shaft of a vehicle drive motor, which can supply lubricating oil to the sliding surface with sufficient oil supply without forced oil supply, and can suppress the generation of vibration and noise while fully cooling the sliding surface and its vicinity.

[0022] Technical solutions adopted to solve technical problems

[0023] To solve the aforementioned technical problems, the inventors conducted extensive and dedicated research. The results showed that, firstly, an opening connecting the inner and outer circumferential surfaces (which serve as sliding surfaces) is provided on the metal substrate supporting the rotating shaft of the vehicle drive motor. A connecting passage, with one opening communicating with the opening in the metal substrate and the other opening opening to the outside or inside of the housing, is provided on the outer casing. These openings are arranged with optimized orientation, position, and size. Furthermore, it was found that, thereby, lubricating oil for lubricating the sliding surfaces is sequentially discharged from the metal substrate via the opening and connecting passage. Therefore, newly injected lubricating oil can be efficiently introduced into the lubricating oil supply passage formed by the bearing clearance between the inner circumferential surface of the metal substrate and the outer circumferential surface of the rotating shaft, thus completing the present invention.

[0024] That is, the present invention provides a sliding bearing device for the rotating shaft of a vehicle drive motor, which supports the rotating shaft of the vehicle drive motor as a rotatable sliding bearing device, comprising: a cylindrical metal base, the metal base including an inner peripheral surface, an outer peripheral surface and two axial end faces; a housing having one or more bearing retaining holes for holding the metal base and capable of internally accommodating at least a portion of the rotating shaft, rotor and stator of the vehicle drive motor; and a lubricating oil inlet, the lubricating oil inlet introducing lubricating oil from the outside to the inside of the housing, the metal base having one or more openings arranged to communicate between the inner peripheral surface and the outer peripheral surface, the housing having one or more connecting passages, one opening of which communicates with the opening of the metal base on the outer peripheral surface side, and the other opening opening to the outside or inside of the housing, thereby ensuring a lubricating oil supply passage between the inner peripheral surface of the metal base and the outer peripheral surface of the rotating shaft. The lubricating oil supply passage is used to supply the lubricating oil introduced into the interior of the housing through the lubricating oil inlet to the inner circumferential surface, which serves as the bearing sliding surface. In the metal substrate, when the central axis of the metal substrate is arranged to intersect with a plane perpendicular to the direction of gravity at an angle of less than 10°, the axis of the opening passage is arranged within a range of 90° relative to the gravity line along the direction of gravity, and the opening passage is arranged near the center of the metal substrate in the axial width direction. The connecting passage provided in the housing is arranged such that the path from one opening to the other opening is a path that does not face the direction opposite to the direction of gravity. The minimum diameter B of the section of the opening passage of the metal substrate perpendicular to the axial direction of the opening passage and the minimum diameter R of the section of the connecting passage of the housing perpendicular to the axial direction of the connecting passage satisfy the relationship expressed by the following formula (1).

[0025] B ≤ 2R (1)

[0026] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention is more preferably constructed in the above-described form with the following structure: the minimum diameter B of the opening path of the metal substrate and the minimum diameter R of the connecting path of the housing satisfy the relationship expressed by the following formula (2).

[0027] B ≤ R (2)

[0028] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention is more preferably configured in the above-described form as follows: the axis of the opening path of the metal substrate is arranged within a range of 60° relative to the gravity line along the direction of gravity, with respect to the central axis.

[0029] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention is further preferably configured in the above-described form with the following structure: the axis of the opening path of the metal substrate is arranged within a range of 45° relative to the gravity line along the direction of gravity, measured from the angle centered on the central axis.

[0030] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention can also adopt the following structure in the above-described form: the lubricating oil inlet sprays or drips or supplies the lubricating oil in a drip manner toward the rotating shaft of the vehicle drive motor disposed inside the housing.

[0031] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention can be configured in the above-described form as follows: the lubricating oil inlet includes at least an oil injection unit disposed inside the housing, through which the lubricating oil is supplied by spraying it toward the rotating shaft of the vehicle drive motor.

[0032] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention can adopt the following structure in the above-described form: the lubricating oil inlet includes at least a gutter-like component, the gutter-like component is disposed inside the housing and introduces the lubricating oil from the outside, the gutter-like component is disposed on the side opposite to the direction of gravity when viewed along the rotating shaft of the vehicle drive motor, and has one or more outlets disposed at positions that can supply the lubricating oil to the rotating shaft and the rotor by dripping or in a hanging manner.

[0033] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention can adopt the following structure in the above-described form: the lubricating oil inlet includes at least a lubricating oil supply pipe, the lubricating oil supply pipe is disposed inside the housing and introduces the lubricating oil from the outside, the lubricating oil supply pipe is disposed on the side opposite to the direction of gravity when viewed along the rotating shaft of the vehicle drive motor, and has one or more outlets disposed at positions that can supply the lubricating oil to the rotating shaft and the rotor by dripping or in a hanging manner.

[0034] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention can adopt the following structure in the above-described form: the rotating shaft of the vehicle drive motor is hollow, the internal space of the rotating shaft is configured as a axial flow path for the flow of lubricating oil, and the rotating shaft includes: an inlet provided at at least one end for introducing the lubricating oil from the lubricating oil inlet into the axial flow path; and an outlet opening from the axial flow path to the outer peripheral surface of the rotating shaft, through which the lubricating oil introduced into the axial flow path flows out by the centrifugal force accompanying the rotation of the rotating shaft, thereby supplying the lubricating oil in a manner that allows it to be suspended on the outer peripheral surface of the rotating shaft.

[0035] The sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention can be configured in the above-described form as follows: the opening of the other side of the connecting passage of the housing opens into the interior of the housing; the lubricating oil supplied to the inner peripheral surface of the metal substrate is discharged into the interior of the housing and stored via the opening passage and the connecting passage; and a remaining portion of the lubricating oil supplied from the lubricating oil inlet to the rotating shaft of the vehicle drive motor falls into the housing and is stored; and a portion of the lubricating oil stored inside the housing is configured to splash as the rotor and rotating shaft of the vehicle drive motor rotate, thereby supplying it again to the inner peripheral surface of the metal substrate, thus circulating the lubricating oil.

[0036] Furthermore, the direction of gravity described in this specification is generally referred to as the vertical direction, which means the direction in which gravity acts. In this specification, the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention is installed in vehicles such as electric vehicles, and cases with a slight tilt or the vehicle itself being tilted are also envisioned, as mentioned above, referred to as the direction of gravity.

[0037] Furthermore, the gravity lines described in this specification are lines along the aforementioned direction of gravity, referring to the direction of gravity acting on objects on Earth, i.e., the lines connecting objects existing on Earth to the Earth's center.

[0038] Furthermore, the gutter-like components described in this specification are generally components with a cross-section shaped like a ko or a C, and which open in the direction opposite to the direction of gravity. For example, they refer to components that allow liquids to flow inside.

[0039] Invention Effects

[0040] According to the present invention, the sliding bearing device for the rotating shaft of the vehicle drive motor, as described above, has a metal substrate having an opening that communicates between an inner circumferential surface and an outer circumferential surface, and a housing having a communication path, wherein one opening of the communication path communicates with the opening of the metal substrate on the outer circumferential surface side, and the other opening opens to the outside or inside of the housing; furthermore, the opening of the metal substrate and the communication path of the housing are configured with an orientation, position and size set in an optimized manner relative to the direction of gravity.

[0041] Therefore, the lubricating oil used to lubricate the inner circumferential surface of the metal substrate, which serves as the sliding surface, is sequentially discharged from the metal substrate through the opening and connecting passages. Thus, the newly injected lubricating oil can be efficiently introduced into the lubricating oil supply passage formed by the bearing clearance between the inner circumferential surface of the metal substrate and the outer circumferential surface of the rotating shaft.

[0042] Therefore, a sliding bearing device can be made to supply lubricating oil to the sliding surface with sufficient oil supply without forced oil supply, and can suppress the generation of vibration and noise while fully cooling the sliding surface and its vicinity.

[0043] Other objects, features and advantages of the present invention will become clear from the accompanying drawings and the following description of embodiments of the invention. Attached Figure Description

[0044] Figure 1 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention. It is a cross-sectional view showing an example of a vehicle drive motor in which the metal substrate constituting the sliding bearing is held in the housing, cut along the axial direction of the metal substrate.

[0045] Figure 2 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor according to the present invention. Figure 2 (a) is Figure 1 The AA section view shown, Figure 2 (b) is Figure 2 The BB section view shown in (a).

[0046] Figure 3 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor according to the present invention. Figure 3(a) to (d) are cross-sectional views showing other examples of the orientation and position of the openings provided in the metal substrate and the connecting passages provided in the housing.

[0047] Figure 4 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention, and is a cross-sectional view that schematically shows the relationship between the minimum diameter B of the opening path of the metal substrate and the minimum diameter R of the connecting path of the housing.

[0048] Figure 5 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor according to the present invention. Figure 5 (a) and (b) are cross-sectional views that schematically show other examples of metal substrates.

[0049] Figure 6 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor according to the present invention. Figure 6 (a) and (b) are cross-sectional views that schematically show other examples of metal substrates.

[0050] Figure 7 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor according to the present invention. Figure 7 (a) to (c) are partial cross-sectional views of examples of the layered structure of a metal matrix, respectively.

[0051] Figure 8 This is a schematic illustration of an embodiment of the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention, and is a cross-sectional view showing another example of a vehicle drive motor in which the metal substrate is held in the housing, cut along the axial direction of the metal substrate. Detailed Implementation

[0052] Hereinafter, embodiments of the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention will be described in detail with appropriate reference to the accompanying drawings.

[0053] Furthermore, for convenience, the figures used in the following description sometimes show the characteristic parts slightly enlarged, and the dimensions and proportions of the constituent elements may sometimes differ from the actual dimensions, in order to understand the characteristics of the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention. In addition, the materials, dimensions, etc., illustrated in the following description are examples, and the present invention is not limited thereto; appropriate modifications can be made to implement it without changing its spirit.

[0054] In this specification, terms such as "orthogonal," "direction," length, and angle that define shape, geometric conditions, and their degree are not limited to the strict meaning and can be interpreted as encompassing a range of degrees to which the same function can be expected.

[0055] In this specification, when multiple candidates for upper limit values ​​and multiple candidates for lower limit values ​​are listed for a certain parameter, the numerical range of the parameter can be a combination of any candidate for upper limit value and any candidate for lower limit value.

[0056] <Structure of the sliding bearing assembly of the vehicle drive motor and its rotating shaft>

[0057] Figure 1 This is a schematic illustration of the sliding bearing device (hereinafter, sometimes simply referred to as the sliding bearing device) 10 of the rotating shaft of the vehicle drive motor in this embodiment. It is a cross-sectional view showing the vehicle drive motor 1 as a whole, with the metal base 10A constituting the sliding bearing device 10 held in the housing 2, and cut along the axial direction X of the metal base 10A. Figure 2 (a) is Figure 1 The AA section view shown, Figure 2 (b) is Figure 2 The BB section view shown in (a).

[0058] Figure 3 (a) to (d) are cross-sectional views showing other examples of the orientation and position of the opening 11 provided in the metal substrate 10A and the connecting 21 provided in the housing 2.

[0059] Figure 4 It is a cross-sectional view that schematically shows the relationship between the minimum diameter B of the opening path 11 of the metal substrate 10A and the minimum diameter R of the connecting path 21 of the outer casing 2.

[0060] Figure 7 (a) to (c) are partial cross-sectional views of examples of the layered structure of a metal matrix, respectively.

[0061] Figure 8 This is a cross-sectional view showing another example of a vehicle drive motor 1A being held in the housing 2, and cut along the axial direction X of the metal substrate 10A.

[0062] like Figure 1 As shown, the sliding bearing device 10 of this embodiment supports the rotating shaft 6 of the vehicle drive motor 1 so that it can rotate, and is composed of a metal base 10A, a housing 2 and a lubricating oil inlet 7.

[0063] Furthermore, the vehicle drive motor 1 equipped with the sliding bearing device 10 of this embodiment is configured to also include a stator 4, a rotor 5, and a rotating shaft 6, which are wholly or partially housed inside the housing 2. The vehicle drive motor 1 is configured such that at least one other end 64 of the rotating shaft 6 protrudes from the housing 2, thereby enabling its rotational power to be transmitted to the outside.

[0064] In addition, such as Figure 2 As shown in the cross-sectional view, the sliding bearing device 10 is configured to include a generally cylindrical metal substrate 10A, and is configured such that the rotating shaft 6 of the vehicle drive motor 1 passes through the cylindrical inner circumferential surface 10b. The axial direction X and central axis S of the cylindrical shape of the sliding bearing device 10 coincide with the axial direction X and central axis S of the rotating shaft 6 of the vehicle drive motor 1, and are referred to by the same reference numerals in this specification. Furthermore, the cylindrical inner circumferential surface 10b of the metal substrate 10A of the sliding bearing device 10 serves as a sliding surface supporting the rotating shaft 6. Also, although in Figure 2 Detailed illustrations are omitted, but the space between the inner circumferential surface 10b of the sliding bearing device 10 and the rotating shaft 6 is filled with lubricating oil L, or the amount of lubricating oil L is sufficient to achieve smooth sliding.

[0065] As a vehicle driven by the vehicle drive motor 1, examples include electric vehicles and railway vehicles. Furthermore, the vehicle drive motor using the sliding bearing device 10 of this embodiment is an oil-cooled motor that uses lubricating oil.

[0066] In this embodiment, as described above, the sliding bearing device 10, which serves as the rotating shaft 6 of the vehicle drive motor 1, is described in terms of its structure, which includes a metal substrate 10A, a housing 2, and a lubricating oil inlet 7. The metal substrate 10A is a component that has the main function of a sliding bearing.

[0067] First, refer to Figure 1 The components other than the sliding bearing assembly 10 constituting the vehicle drive motor 1 will be described.

[0068] The stator 4 and rotor 5 generate power for the vehicle drive motor 1 through magnetic force.

[0069] The stator 4 is installed inside the housing 2 and has a coil 4A that generates electromagnetic force by applying current. The stator is arranged to surround the rotor 5 from the circumferential direction. The coil 4A is connected to the power supply via wiring (not shown). Furthermore, the stator 4 is located inside the housing 2 at a position further away from the rotation axis 6 than the rotor 5.

[0070] Rotor 5 is a rotor that has the function of generating a magnetic field. Rotating shaft 6 is mounted on the axis of rotor 5. As rotor 5 rotates, rotating shaft 6 rotates together with rotor 5, thereby extracting rotational power as the vehicle drive motor 1.

[0071] As described above, the rotating shaft 6 transmits the rotational power generated by the vehicle drive motor 1 to the outside, thus constituting a configuration where... Figure 1 The elongated cylindrical rod shown extends along the axial direction X and rotates about the central axis S. Furthermore, the other end 64 of the rotating shaft 6 protrudes outwards from the exterior of the housing 2.

[0072] The rotating shaft 6 can also be connected to a reducer (not shown) for increasing rotational torque, as needed.

[0073] As described above, in the vehicle drive motor 1, within the housing 2, the stator 4 is disposed on the outer side relative to the rotating shaft 6, and the rotor 5, connected to the rotating shaft 6, is disposed on the inner side of the stator 4. In this structure, when energized from a power source (not shown), the coil 4A of the stator 4 generates a magnetic field. The rotor 5 rotates due to the interaction between this magnetic field and the magnetic field generated by the rotor 5, and the rotating shaft 6 rotates accordingly. Furthermore, by outputting the rotational power of the rotating shaft 6 to the outside, it can be used as the power source for driving vehicles, etc.

[0074] Next, the structure of the sliding bearing device 10 will be described in detail with reference to the above figures.

[0075] The outer casing 2 is fitted with a metal substrate 10A, thereby constituting the sliding bearing device 10 of this embodiment. Furthermore, other components constituting the vehicle drive motor 1 are housed in the internal space 2A, thereby serving as the frame of the vehicle drive motor 1.

[0076] That is, the housing 2 has one or more bearing retaining holes 3 for holding the metal substrate 10A, and is configured to internally house at least a portion of the rotating shaft 6, stator 4, and rotor 5 of the vehicle drive motor 1. In the illustrated example, the housing 2 has two bearing retaining holes 3, each holding a metal substrate 10A. Thus, one end 65 of the rotating shaft 6 is supported near the metal substrate 10A held in one bearing retaining hole 3, and the other end 64 of the rotating shaft 6 is supported near the metal substrate 10A held in the other bearing retaining hole 3.

[0077] The bearing retaining hole 3 can penetrate the housing 2 in the thickness direction throughout, or it can be formed as a concave hole that opens into the housing 2, for example, a hole that retains the metal substrate 10A, which is a circular hole with an inner surface in a roughly cylindrical shape. Figure 1In the example shown, the bearing retaining hole 3 located at the other end 64 of the rotating shaft 6 penetrates the housing 2, and is configured such that the other end 64 protrudes to the outside of the housing 2. On the other hand, the bearing retaining hole 3 located at one end 65 of the rotating shaft 6 is formed as a concave shape that can accommodate one end 65 inside, without penetrating the housing 2. The internal shape, surface finishing, inner diameter, etc. of the bearing retaining hole 3 are optimized in a way that appropriately adjusts the interference fit (in other words, the press-in amount) of the metal substrate 10A, thereby properly and securely holding the metal substrate 10A.

[0078] Furthermore, by setting the bearing retaining hole 3 to pass through both one end 65 and the other end 64 of the rotating shaft 6, a vehicle drive motor with a so-called two-shaft structure in which both ends of the rotating shaft 6 are exposed to the outside can also be constructed.

[0079] In this embodiment, the bearing retaining hole 3 is constructed as a single unit rather than divided into multiple parts. However, it is not limited to this. For example, the housing 2 can be constructed from multiple components in such a way that the inner surface of the bearing retaining hole 3 is divided into multiple parts.

[0080] In the sliding bearing device 10 of this embodiment, the metal substrate 10A is a component that supports the rotating shaft 6 of the vehicle drive motor 1 so that it can rotate, and is configured as a cylindrical shape including an inner peripheral surface 10b, an outer peripheral surface 10a and two axial end surfaces 10c, 10c.

[0081] like Figure 1 and Figure 2 As shown in (a), the metal substrate 10A has an opening 11 at a point along its circumference, the opening 11 being configured to face along the direction of gravity G.

[0082] In the sliding bearing device 10 of this embodiment, the outer casing 2 has one or more connecting passages 21, wherein one opening 21a communicates with the opening passage 11 of the metal substrate 10A on the outer peripheral surface 10a side, and the other opening 21b opens to the outside or inside of the outer casing 2. Figure 1 In the example shown, the connecting path 21 is provided at two locations corresponding to the metal substrate 10A held at two locations, and the opening 21b of the other is configured to communicate with the internal space (interior) 2A of the outer shell 2.

[0083] Furthermore, a lubricating oil supply path 30 is provided between the inner peripheral surface 10b of the metal substrate 10A and the outer peripheral surface 6a of the rotating shaft 6. The lubricating oil supply path 30 is a bearing clearance for supplying lubricating oil L, which is introduced into the interior of the housing 2 through the lubricating oil inlet 7, to the inner peripheral surface 10b, which serves as a sliding surface.

[0084] In addition, such as Figure 3As shown in (a), when the central axis S of the metal substrate 10A is arranged to intersect the plane perpendicular to the direction of gravity G at an angle of less than 10°, the axis of the opening passage 11, measured with respect to the central axis S, is arranged within a range that forms an angle of 90° with respect to the gravity line P along the direction of gravity G. Furthermore, the opening passage 11 is arranged near the center of the width W along the axial direction X of the metal substrate 10A (see also [reference]). Figure 2 (b)

[0085] Furthermore, the connecting path 21 provided in the outer casing 2 is configured such that the entire path from one opening 21a to the other opening 21b is a path that does not face the direction opposite to the direction of gravity G.

[0086] And, as Figure 4 As shown, in the sliding bearing device 10 of this embodiment, the minimum diameter B of the cross section perpendicular to the axial direction of the opening path 11 of the metal substrate 10A and the minimum diameter R of the cross section perpendicular to the axial direction of the connecting path 21 of the housing 2 are configured to satisfy the relationship expressed by the following formula (1).

[0087] B ≤ 2R (1)

[0088] The lubricating oil inlet 7 introduces lubricating oil L from the outside toward the inside of the housing 2.

[0089] Figure 1 The lubricating oil inlet 7 in the example shown includes: a lubricating oil reservoir 71 for storing lubricating oil L; a pipe 72 for supplying lubricating oil L supplied from the lubricating oil reservoir 71; and an oil nozzle (oil spraying unit) 73 for introducing the lubricating oil L supplied from the pipe 72 into the internal space 2A of the housing 2. In the illustrated example, the oil nozzle 73 is disposed in the internal space 2A of the housing 2.

[0090] Lubricating oil L stored in the lubricating oil tank 71 is supplied to the oil nozzle 73 via a pump (not shown) through a pipe 72. The oil nozzle 73 then sprays the lubricating oil L toward the rotating shaft 6 of the vehicle drive motor 1.

[0091] According to the sliding bearing device 10 of this embodiment, in particular by setting the opening 11 of the metal substrate 10A and the connecting passage 21 of the housing 2 in the above-described orientation, configuration and size, the following functions and effects can be obtained.

[0092] First, by arranging the axis of the opening 11 of the metal substrate 10A at an angle within the aforementioned range relative to the gravity line P along the direction of gravity G, the lubricating oil L flowing in from one opening 11a of the opening 11 towards the other opening 11b can flow not only under the oil film pressure generated by the sliding surface, but also, for example, under gravity alone. With the discovery of these various effects, the oil discharge of the lubricating oil L from the other opening 11b becomes better, enabling efficient introduction into one opening 11a of the connecting passage 21 of the housing 2.

[0093] Furthermore, in the connecting passage 21 of the outer casing 2, the other opening 11b is positioned lower than the other opening 11a in the direction of gravity (vertical direction) G. Therefore, the lubricating oil L flowing in from the opening passage 11 of the metal substrate 10A can be discharged under the influence of gravity alone. This improves the dischargeability of the lubricating oil L, thereby enhancing its exchangeability.

[0094] Furthermore, the minimum diameter B of the opening 11 and the minimum diameter R of the connecting passage 21 satisfy the relationship expressed by the above formula (1). As a result, the lubricating oil L flows efficiently not only under the aforementioned oil film pressure but also under the influence of gravity alone, without stagnating at their connecting parts. Thus, the lubricating oil can be efficiently discharged from the opening 11b on the other side of the connecting passage 21.

[0095] In this embodiment, the lubricating oil L is supplied to the inner peripheral surface 10b of the metal substrate 10A at the inlet of the lubricating oil supply passage 30, i.e., the bearing clearance between the metal substrate 10A and the rotating shaft 6. On the other hand, the lubricating oil L is discharged from the inner peripheral surface 10b at the opening passage 11, at different locations. Therefore, unlike conventional housings where, for example, the oil supply and discharge portions in the bearing clearance overlap, collisions between the supplied and discharged lubricating oil L can be avoided. Consequently, the lubricating oil L is efficiently discharged from the inner peripheral surface 10b of the metal substrate 10A, and a sufficient amount of lubricating oil L is supplied via the lubricating oil supply passage 30, resulting in smooth flow of the lubricating oil L and improved exchangeability.

[0096] Furthermore, from the viewpoint that the lubricating oil L can reliably flow out from the opening 11 of the metal substrate 10A and the connecting passage 21 of the outer casing 2 in the direction of gravity, it is more preferable that the minimum diameter B and the minimum diameter R are configured to satisfy the relationship expressed by the following formula (2). As a result, the discharge and exchange properties of the lubricating oil L of the sliding bearing device 10 are more excellent.

[0097] B ≤ R (2)

[0098] Furthermore, similarly to the above, from the viewpoint that lubricating oil L reliably flows out from the opening 11 of the metal substrate 10A in the direction of gravity, such as Figure 3 As shown in (b), more preferably, the axis of the opening path 11 is arranged within a range of 60° relative to the gravity line P along the direction of gravity, measured with respect to the central axis S. Furthermore, from the above viewpoint, it is even more preferable that the axis of the opening path 11 is arranged within a range of 45° relative to the gravity line P along the direction of gravity, measured with respect to the central axis S.

[0099] The minimum diameter B of the opening 11 of the metal substrate 10A is not particularly limited, but as... Figure 2 As shown in example (b), it is preferable that the width W of the metal substrate 10A, after removing the chamfered portion from the overall width along the axial direction X, is less than 1 / 3 of the diameter. Figure 2 In the example shown in (b), a chamfer is applied to the outer peripheral surface 10a at the position adjacent to the end faces 10c, 10c in each axial direction, as detailed below. By setting the dimensions of the opening 11 to the dimensions described above, sufficient load capacity as a bearing can be ensured.

[0100] Furthermore, the width W of the metal substrate 10A and the diameter of the inner circumferential surface 10b are not particularly limited, but their use as a vehicle drive motor 1 and the outer diameter of the rotating shaft 6 are also taken into consideration. For example, the diameter of the inner circumferential surface 10b can be set to 10 to 50 mm, and the width W along the axial direction X can be set to 2 to 50 mm.

[0101] Furthermore, when the metal substrate 10A is configured such that no chamfering is applied to the position where the outer peripheral surface 10a is adjacent to the end surfaces 10c, 10c in each axial direction, the overall width of the metal substrate 10A is the aforementioned width W.

[0102] The minimum diameter R of the connecting passage 21 in the housing 2 is not particularly limited, but from the viewpoint of the discharge of lubricating oil L, it is preferably 1 mm or more, and more preferably 2 mm or more.

[0103] In addition, when the cross-sectional shape of the metal substrate 10A and the outer shell 2 is affected by factors such as processing accuracy and becomes an ellipse or other shape different from a circle, the average diameter corresponding to each cross-sectional shape is calculated, and this value is used as the minimum diameter B and R mentioned above. The design is made to be included in the above range.

[0104] Furthermore, the thickness of the metal substrate 10A is not particularly limited, and can be determined by considering the difference between the diameter of the inner circumferential surface 10b and the outer diameter (the diameter of the outer circumferential surface 10a side) and strength characteristics. From the viewpoint of strength, the thickness of the metal substrate 10A is preferably 0.8 mm or more. On the other hand, if the thickness of the metal substrate 10A is too large, there is a concern that the outer diameter will be too large; therefore, it is preferably 3 mm or less. In addition, the thickness of the metal substrate 10A can be fixed throughout the entire circumferential direction.

[0105] Furthermore, when the metal substrate is configured as a structure consisting of multiple layers as described below, the total thickness of all layers can be set to the thickness within the range mentioned above.

[0106] In addition, such as Figure 3 As shown in example (c), when the metal substrate 10A has multiple openings and correspondingly multiple connecting passages are also provided on the outer casing 2 sides, at least one connecting passage (and opening) only needs to satisfy the above-mentioned orientation and arrangement position relative to the direction of gravity G and the gravity line P. Figure 3 In the example shown in (c), the metal substrate 10A has two openings 11, and correspondingly two connecting passages 21 and 24. In the illustrated example, the connecting passage 24 is configured to face and be oriented in the opposite direction of the gravitational force G as it moves from one opening 24a to the other opening 24b. On the other hand, the connecting passage 21 is configured to face along the gravitational force G and the gravity line P. In the illustrated example, the connecting passage 21 is configured to allow the lubricating oil L to flow down even under the influence of gravity alone, thus ensuring sufficient drainage of the lubricating oil L.

[0107] In addition, such as Figure 3 As shown in example (c), in the case where the metal substrate 10A has multiple openings and the housing 2 has multiple connecting passages, setting at least one opening and the connecting passage connected thereto to the aforementioned minimum diameters B and R ensures the dischargeability of the lubricating oil L. That is, in the illustrated example, by applying the aforementioned minimum diameters B and R to the connecting passage 21 arranged along the direction of gravity G and the orientation of the gravity line P, sufficient dischargeability of the lubricating oil L can be obtained.

[0108] There are no particular restrictions on the material of the metal substrate 10A; it can be selected based on various characteristics such as sliding properties and mechanical strength.

[0109] In addition, Figures 1-5 The example shown illustrates a single-layer structure with a metal matrix based on a single metal material, but is not limited to this. Other examples of metal matrices include, for instance, those other than... Figure 7In addition to the solid structure shown in the partial sectional view of (a), other structures may also be used. Figure 7 The partial cross-sectional views of (b) and (c) show bimetallic or trimetallic structures with multiple material layers.

[0110] exist Figure 7 In (a) to (c), for ease of illustration, the layered structure of the metal substrate is shown in partial cross-sectional views, but the actual metal substrate 10A is... Figure 1 and Figure 2 The cylindrical shape is shown. Therefore, in the following description, terms such as "inner circumferential surface", "outer circumferential surface", and "circumferential direction" will be used when describing each layer.

[0111] Figure 7 (a) shows an example of a solid structure, for example, consisting of a single bearing alloy layer 13a made of a single metallic material or an alloy material.

[0112] When using a single metal substrate as a bearing alloy layer 13a, materials with properties such as pressure resistance, wear resistance, heat resistance, high thermal conductivity, and low friction can be used to fulfill the function of a bearing that supports the rotating shaft 6 and provides sufficient strength. Examples of such materials include aluminum alloys and copper alloys.

[0113] Furthermore, the thickness of the bearing alloy layer 13a when used as a single layer is not particularly limited, and can be designed with consideration for the strength of the bearing. For example, it can be set to a range of 0.8 mm or more and 3 mm or less, similar to the overall thickness of the metal substrate 10A.

[0114] Furthermore, the thickness of the bearing alloy layer 13a can be fixed throughout the circumferential range, as illustrated in the example.

[0115] Figure 7 (b) shows Figure 7 This is an example of a bimetallic structure shown in (a) where the bearing alloy layer 13a is stacked on the back metal layer 13b. That is, the back metal layer 13b is disposed on the outer peripheral surface side of the metal substrate, and the bearing alloy layer 13a is disposed on the inner peripheral surface side (sliding surface side).

[0116] The back metal layer 13b is preferably made of a material with particularly excellent strength properties and is not easily deformed. Examples of such materials include hypoeutectoid steel and stainless steel containing 0.05% to 0.5% carbon by mass.

[0117] In Adoption Figure 7In the case of the bimetallic structure shown in (b), the back metal layer 13b serves as the substrate supporting the bearing alloy layer 13a. By using a high-strength material for the back metal layer 13b, strength can be ensured even when the bearing alloy layer 13a is laminated, thus reducing the overall thickness.

[0118] In this case, the thickness of the back metal layer 13b can be set, for example, to a range of more than 0.5 mm and less than 2.8 mm.

[0119] Furthermore, the thickness of the back metal layer 13b can be fixed throughout the circumferential range, as illustrated in the example.

[0120] The thickness of the bearing alloy layer 13a when using the above-described bimetallic structure is not particularly limited. For example, it can be set to a range of 0.1 mm or more and 0.5 mm or less. In addition, it can be fixed in the entire circumferential range as shown in the example.

[0121] Furthermore, when a bimetallic structure is used, the total thickness of the bearing alloy layer 13a and the back metal layer 13b is not particularly limited. For example, it can be set to the same range of 0.8 mm or more and 3 mm or less as when the bearing alloy layer 13a is used in a solid structure. It can also be fixed in the entire circumferential range as described above.

[0122] Figure 7 (c) shows in Figure 7 This is an example of a trimetallic structure in which a cover layer 13c is further laminated on the bearing alloy layer 13a based on the layer structure shown in (b). The cover layer 13c is disposed on the inner peripheral side of the metal substrate in such a way that it serves as the sliding surface of the sliding bearing device.

[0123] The material used for the covering layer 13c is not particularly limited; for example, metal plating and resin are examples.

[0124] Furthermore, the thickness of the capping layer 13c is not particularly limited, and can be set to a range of 1 μm or more and 30 μm or less. Additionally, the thickness of the capping layer 13c can be fixed over the entire circumferential direction, as illustrated in the example.

[0125] The thickness of the bearing alloy layer 13a and the back metal layer 13b when using the above-described three-metal structure is not particularly limited. For example, each layer can be set to the same thickness as described above. In addition, it can be fixed throughout the circumferential range as shown in the example.

[0126] Furthermore, when using a trimetallic structure, the total thickness of the bearing alloy layer 13a, the back metal layer 13b, and the cover layer 13c is not particularly limited. It can be set to a range of 0.8 mm or more and 3 mm or less, similar to the solid structure and bimetallic structure described above. It can also be fixed in the entire circumferential range, just as described above.

[0127] In the above-mentioned layered structures, especially when using, for example Figure 7 In the case of bimetallic or trimetallic structures shown in (b) and (c), the frictional torque between the inner circumferential surface and the rotating shaft can be significantly reduced.

[0128] The material of the outer casing 2 is not particularly limited; for example, metal materials commonly used for vehicle drive motor casings can be appropriately used.

[0129] Furthermore, in the sliding bearing device 10 of this embodiment, as long as the minimum diameter R of the connecting passage 21 of the housing 2 is configured such that there is no extremely narrowing part in the path from one opening 21a to the other opening 21b, the lubricating oil L can be discharged with less internal resistance, thus ensuring excellent exchangeability of the lubricating oil L.

[0130] Furthermore, the connecting path provided in the casing is not limited to being completely straight; it can also be bent or curved at one or more locations along its length. For example, it can be as follows: Figure 3 As illustrated in (d), the connecting path 25 is structured such that it bends at a bend 25c as it moves from one opening 25a toward the other opening 25b. The illustrated example connecting path 25 consists of a straight upstream path 25A disposed on the side of one opening 25a with the bend 25c as its boundary, and a straight downstream path 25B disposed on the side of the other opening 25b.

[0131] In the aforementioned connecting path 25, the path as a whole is also inclined towards the direction of gravity G of the opening 25b on the other side, so that the lubricating oil L can flow out under the action of gravity alone and will not remain in the position or path of the opening 25a on one side. Therefore, the discharge of the lubricating oil L is fully ensured.

[0132] By configuring the minimum diameter B of the opening 11 of the metal substrate 10A and the minimum diameter R of the connecting path of the outer casing 2 to satisfy the relationship expressed by the above formula (1) or formula (2) regardless of the shape of the connecting path along its length, the lubricating oil L can be discharged toward the opening of the connecting path without increasing the pressure.

[0133] In the sliding bearing device 10 of this embodiment, preferably, the opening 11a of one of the opening paths 11 of the metal substrate 10A is disposed in the inner peripheral surface 10b at a position where oil film pressure is generated accompanying the rotation of the rotating shaft 6.

[0134] That is, for example, if the location where oil film pressure is generated in the inner peripheral surface 10b of the metal substrate 10A is a position that covers the entire circumferential direction of the inner peripheral surface 10b, and is a position near the center in the width direction along the axial direction X, it is more preferable to arrange one of the opening portions 11a of the opening passage 11 at this position.

[0135] Generally, the location where oil film pressure is generated in the sliding bearing device 10 is in the width direction of the inner circumferential surface 10b of the metal substrate 10A. Figure 1 Near the center of the horizontal direction on the paper, and the entire circumferential region of the land portion (sliding portion) of the inner circumferential surface 10b. That is, by placing one of the opening portions 11a of the opening path 11 in such a way as Figure 1 In the example of the sliding bearing device 10, the used lubricating oil L can be efficiently discharged using the oil film pressure. Simultaneously, fresh lubricating oil L can more easily enter the lubricating oil supply path 30, thus further improving the exchangeability of the lubricating oil L.

[0136] In the example described in this embodiment, a metal substrate 10A with the above-described structure is arranged on both the side of one end 65 and the other end 64 of the rotating shaft 6 of the vehicle drive motor 1, which allows lubricating oil L to be discharged from both ends through these two metal substrates 10A, but it is not limited to this. For example, the metal substrate 10A with the structure described in this embodiment may be arranged only on either of the two bearing retaining holes 3 of the housing 2, and even with this structure, the effect of improved discharge and exchange of lubricating oil L can be fully obtained.

[0137] Alternatively, for example, a structure may be adopted in which bearing retaining holes 3 are provided at three or more locations along the axial direction X of the rotation axis 6 on the housing 2, and metal substrates 10A are respectively provided thereon, thereby providing a sliding bearing device 10 at three or more locations.

[0138] The sliding bearing device 10 in this embodiment and the lubricating oil L used in the vehicle drive motor 1 equipped with the sliding bearing device 10 are not particularly limited. For example, in addition to CVTF (Continuously Variable Transmission Fluid), gear oil, EVF (Electric Vehicle Fluid), refrigerant, etc., can be cited as such lubricating oil L.

[0139] Here, the opening 11 and connecting 21 of the sliding bearing device 10 in this embodiment are structures that discharge lubricating oil L from the inner peripheral surface 10b of the metal substrate 10A, for example, and are not structures that allow air or other gases to circulate.

[0140] On the other hand, for example, in cases where the openings and connecting passages are configured to allow air to flow actively from the outside for purposes different from those of the present invention, the air may become blocked as it flows through them, making it impossible to ensure a proper discharge path for the lubricating oil from the inner circumferential surface of the metal substrate. In such cases, the dischargeability of the lubricating oil from the sliding surface decreases, and the exchangeability of the lubricating oil deteriorates, which may result in difficulty in supplying lubricating oil to the inner circumferential surface from the lubricating oil supply passage that serves as a bearing clearance.

[0141] In the sliding bearing device 10 of this embodiment, as described above, the lubricating oil L from the inner circumferential surface 10b is discharged and the lubricating oil L is supplied from the bearing clearance toward the inner circumferential surface 10b via different paths, and each path employs a structure that allows only the lubricating oil L to flow. Therefore, as the discharge and exchange properties of the lubricating oil L are improved, the possibility of air flowing from outside the bearing through the connecting passage 21 and the opening passage 11 is eliminated or becomes very difficult to overcome. Furthermore, even if a small amount of air accidentally and unavoidably flows into the connecting passage 21 and the opening passage 11 from outside the bearing, the above-described structure can minimize the air inflow and maintain the excellent discharge and exchange properties of the lubricating oil L.

[0142] In a vehicle drive motor 1 configured to include the sliding bearing device 10 of this embodiment, for example, the circulation path of the lubricating oil L can be ensured through the actions described below.

[0143] For example, the opening 21b of at least a portion of the multiple connecting passages 21 provided in the housing 2 faces the external opening of the housing 2 (details omitted). In the above configuration, at least a portion of the used or remaining lubricating oil L supplied to the inner peripheral surface 10b of the metal substrate 10A is discharged to the outside of the housing 2 via the opening passage 11 and the connecting passage 21. The lubricating oil L discharged to the outside of the housing 2 flows back to the lubricating oil tank 71 of the lubricating oil inlet 7 via a pump (not shown) and circulation piping, and is then reintroduced into the interior of the housing 2 via piping 72, etc., thereby supplying it again to the rotor 5 and rotating shaft 6 of the vehicle drive motor 1. At this time, the re-supplying lubricating oil L propagates on the outer peripheral surface 6a of the rotating shaft 6 and is supplied again to the inner peripheral surface 10b of the metal substrate 10A via the lubricating oil supply passage 30.

[0144] Alternatively, in this embodiment, for example, the following circulation path can be adopted: the lubricating oil L discharged to the outside of the housing 2 first flows back to the lubricating oil tank 71 through the circulation piping (not shown), and the lubricating oil L drawn from the lubricating oil tank 71 by the pump (not shown) is introduced back into the inside of the housing 2 through the piping 72, etc.

[0145] As described above, by repeatedly circulating at least a portion of the lubricating oil L discharged to the outside of the housing 2 and supplying it again to the inner circumferential surface 10b of the metal substrate 10A, which serves as the sliding surface, the lubricating oil L can be utilized efficiently without waste. Furthermore, the amount of lubricating oil L used in the sliding bearing assembly 10 and even the entire vehicle drive motor 1 can be reduced.

[0146] In addition, according to Figure 1 , Figure 8 The vehicle drive motor equipped with a sliding bearing device, as described below, can employ a structure in which lubricating oil L, which is discharged through the aforementioned opening 11 and connecting passage 21 to the internal space 2A of the housing 2, or supplied to the rotating shaft 6 or rotor 5 and then flows down into and stored in the internal space 2A of the housing 2, is re-supplied to the inner peripheral surface 10b of the metal substrate 10A.

[0147] The flow that circulates the lubricating oil L stored in the internal space 2A and supplies it again to the inner peripheral surface 10b of the metal substrate 10A is described in detail below.

[0148] exist Figure 1 In the example shown, in the housing 2, the opening 21b on the other side of the connecting passage 21 opens into the internal space 2A of the housing 2. The lubricating oil L supplied to the inner peripheral surface 10b of the metal substrate 10A for cooling the sliding surface is discharged into the internal space 2A of the housing 2 via the opening passage 11 and the connecting passage 21 and stored therein. In addition, a portion of the remaining lubricating oil L supplied from the lubricating oil inlet 7 to the rotating shaft 6 or rotor 5 of the vehicle drive motor 1 falls into the housing 2 and is stored in the internal space 2A.

[0149] Furthermore, a portion of the lubricating oil L stored in the internal space 2A of the housing 2 splashes out as the rotor 5 and rotating shaft 6 of the vehicle drive motor 1 rotate. The splashed lubricating oil L is then supplied again to the inner peripheral surface 10b of the metal substrate 10A via the lubricating oil supply passage 30, thereby forming a circulation path for the lubricating oil L.

[0150] As described above, a portion of the lubricating oil L stored in the internal space 2A of the housing 2 is circulated and supplied again to the inner circumferential surface 10b of the metal substrate 10A, which serves as the sliding surface, thereby enabling efficient and waste-free utilization of the lubricating oil L. Furthermore, this reduces the amount of lubricating oil L used in the sliding bearing assembly 10 and even the entire vehicle drive motor 1.

[0151] Furthermore, the vehicle drive motor 1 described in this embodiment is generally installed in a gearbox housing (not shown) in electric vehicles or similar applications. The gearbox is used to both reduce the rotational speed of the rotating shaft 6 of the vehicle drive motor 1 and increase its rotational torque. In this case, the lubricating oil L discharged from the housing 2 to the outside via the connecting passage 21 can be recovered in the gearbox housing and then returned to the lubricating oil reservoir 71 via a pump, piping, etc. (not shown).

[0152] Furthermore, the lubricating oil inlet provided in the sliding bearing device 10 of this embodiment is not limited to... Figure 1 The structure shown has an oil nozzle 73. The lubricating oil inlet can be any structure as long as it can spray or drip lubricating oil L toward the rotating shaft 6 disposed inside the housing 2, or supply it in a drip manner.

[0153] As another example of a lubricating oil inlet, a structure that includes at least an eaves-like component (not shown) disposed inside the housing 2 and introducing lubricating oil L from the outside can be cited.

[0154] As the aforementioned eaves-like component, for example, it can be structured as follows: relative to the rotating shaft 6 of the vehicle drive motor 1, it is positioned on the side opposite to the direction of gravity G when viewed from the rotating shaft 6, and has one or more outlets positioned to allow lubricating oil L to drip onto the rotating shaft 6 and the rotor 5 or to be supplied in a drip manner (detailed illustration omitted).

[0155] According to the lubricating oil inlet including the aforementioned gutter-shaped component, it is possible to obtain lubricating oil from... Figure 1 The lubricating oil tank 71 shown in the figure is supplied with lubricating oil L via piping 72, which is efficiently dripped or dripped toward the rotating shaft 6 and rotor 5.

[0156] In addition, as another example of a lubricating oil inlet, a structure that includes at least a lubricating oil supply pipe (not shown) disposed inside the housing 2 and introducing lubricating oil L from the outside can be cited.

[0157] As an example of the aforementioned lubricating oil supply pipe, a lubricating oil supply pipe can be arranged on the side opposite to the direction of gravity when viewed from the rotating shaft 6 of the vehicle drive motor 1, similar to the one described above. Detailed illustrations are omitted. Furthermore, as a lubricating oil supply pipe, a structure having one or more outlets arranged at positions that allow lubricating oil L to drip onto the rotating shaft 6 and the rotor 5, or to be supplied in a drip manner.

[0158] Similarly, in the case of a lubricating oil inlet portion including the aforementioned lubricating oil supply pipe, and in the case of a lubricating oil inlet portion including the aforementioned gutter-shaped component, it is possible to obtain lubricating oil from... Figure 1The lubricating oil tank 71 shown in the figure is supplied with lubricating oil L via piping 72, which is efficiently dripped or dripped toward the rotating shaft 6 and rotor 5.

[0159] Furthermore, in this embodiment, for example, a structure can be adopted in which the rotating shaft 6 of the vehicle drive motor is used as a supply unit for lubricating oil L.

[0160] Specifically, the following structure can be adopted: (e.g.) Figure 8 As shown in the example of the vehicle drive motor 1A, the rotating shaft 6 is hollow, and the internal space ensured by the inner circumferential surface 6b serves as the axial flow path 6A for the flow of lubricating oil.

[0161] Figure 8 The rotating shaft 6 shown in the figure has an inlet 61 on the other end 64 side protruding from the housing 2. The inlet 61 is used to introduce lubricating oil L from the lubricating oil tank 71 constituting the lubricating oil inlet 7 to the shaft flow path 6A via the pipe 72.

[0162] Furthermore, the rotating shaft 6 in the illustrated example is provided with an outlet 63, which opens from the axial flow path 6A to the outer peripheral surface 6a of the rotating shaft 6. The lubricating oil L introduced into the axial flow path 6A is caused to flow out by the centrifugal force accompanying the rotation of the rotating shaft 6, thereby supplying the lubricating oil L in a manner that hangs on the outer peripheral surface 6a of the rotating shaft 6.

[0163] according to Figure 8 The vehicle drive motor 1A and sliding bearing device 10, as exemplified, enable the lubricating oil L to flow efficiently and evenly on the outer peripheral surface 6a of the rotating shaft 6 by having the above-described structure.

[0164] The following describes the method of assembling the metal substrate 10A into the bearing retaining hole 3 of the housing 2.

[0165] First, a cylindrical metal substrate 10A is pressed into the bearing retaining hole 3 of the housing 2. Here, the outer circumference of the metal substrate 10A before pressing is slightly larger than the inner circumference of the bearing retaining hole 3. Therefore, after the metal substrate 10A is pressed into the bearing retaining hole 3, the outer circumference of the metal substrate 10A and the inner circumference of the bearing retaining hole 3 are pressed together. Due to the aforementioned pressing force, the metal substrate 10A is assembled into the bearing retaining hole 3 by a fitting and fixing method.

[0166] Then, the rotating shaft 6 of the vehicle drive motor 1 is inserted into the inner circumferential surface 10b of the cylindrical metal substrate 10A, which is disposed in the bearing retaining hole 3 of the housing 2. The metal substrate 10A supports the rotating shaft 6 in the appropriate position from the inner circumferential surface 10b side so that it can rotate.

[0167] The processing method for the inner peripheral surface 10b, which serves as the sliding surface in the metal substrate 10A, is not particularly limited. For example, a method can be given by processing a plate-shaped material into a cylindrical or semi-divided shape and performing broaching, boring, or other machining operations on the inner diameter side to form the sliding surface. In addition, a method can be given, for example, by processing a rod-shaped or pipe-shaped material by cutting or other methods to form the desired shape and sliding surface.

[0168] Furthermore, there is no particular limitation on the timing of machining the opening 11 on the metal substrate 10A. For example, it can be done during the machining of the metal substrate 10A, i.e. before it is inserted into the bearing retaining hole 3 of the housing 2, or it can be done at the time of machining together with the housing 2 after it is pressed into the bearing retaining hole 3.

[0169] <Effects>

[0170] As explained above, the sliding bearing device 10 for the rotating shaft of the vehicle drive motor according to this embodiment has a metal substrate 10A having an opening 11 that connects the inner peripheral surface 10b and the outer peripheral surface 10a, and a housing 2 having a connecting passage 21. One opening 21a of the connecting passage 21 connects to the opening 11 of the metal substrate 10A on the outer peripheral surface 10a side, and the other opening 21b opens to the outside or inside of the housing 2. Furthermore, the opening 11 of the metal substrate 10A and the connecting passage 21 of the housing 2 are arranged with an orientation, position and size optimized relative to the direction of gravity G.

[0171] According to the above structure, the lubricating oil L used to lubricate the inner peripheral surface 10b of the metal substrate 10A, which serves as the sliding surface, is sequentially discharged from the metal substrate 10A via the opening passage 11 and the connecting passage 21. Therefore, the newly injected lubricating oil L can be efficiently introduced into the lubricating oil supply passage 30 formed by the bearing gap between the inner peripheral surface 10b of the metal substrate 10A and the outer peripheral surface 6a of the rotating shaft 6.

[0172] Therefore, the lubricating oil L can be supplied to the sliding surface with sufficient oil volume without forced oil supply, which can fully cool the metal base 10A and the rotating shaft 6 that constitute the sliding bearing, while suppressing the generation of vibration and noise.

[0173] <Modifications of the Invention>

[0174] The embodiments of the present invention have been described in detail above. However, the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention is not limited to the above embodiments. Various changes and modifications can be made to implement it as long as it does not depart from the principle of the present invention and the scope of the appended claims.

[0175] For example, in Figure 2In (a), the inner circumferential surface 10b of the metal substrate 10A is shown to be a bushing component of a generally cylindrical shape that is continuously connected in the circumferential direction, but the metal substrate is not limited to components of the above shape. Figure 5 (a), (b) or Figure 6 As shown in examples (a) and (b), the metal substrate can also be made of other shapes.

[0176] Figure 5 (a) and (b) are schematic cross-sectional views of metal substrates 10B and 10C, respectively, illustrating variations of the present invention.

[0177] also, Figure 6 (a) and (b) are also cross-sectional views of metal substrates 10D and 10E, respectively, schematically illustrating variations of the present invention.

[0178] in addition, Figure 5 (a), (b) and Figure 6 For the sake of illustration, the opening paths of each of (a) and (b) are omitted.

[0179] In this invention, for example, the following methods may also be used: Figure 5 The component with a roll bushing structure that is divided at the position of the dividing part 12, as shown in (a) of the metal substrate 10B, can also be made as follows: Figure 5 The component with a semi-divided structure, as shown in (b) with a metal substrate 10C, is divided into two sections 14, 14. Figure 5 The metal substrates 10B and 10C shown in (a) and (b) are aligned such that the dividing portions 12 or 14 are respectively opposite to each other, thereby forming a general cylindrical shape. Furthermore, in Figure 5 In the example metal substrate 10C shown in (b), a structure consisting of two parts metal substrates is formed by adopting the above-described semi-segmented structure.

[0180] Furthermore, the present invention is not limited to, for example, Figure 2 As shown in example (a), the inner circumferential surface is formed by an arc. For example, it can also be as follows: Figure 6 As shown in (a), the metal substrate 10D has an inner circumferential surface 10b with a structure based on two semicircular arcs, or it can be like... Figure 6 As shown in (b), the inner circumferential surface 10b of the metal substrate 10E is a three-arc structure with uniform dimensions. In the illustrated example, the inner circumferential surface 10b of the metal substrates 10D and 10E is formed into multiple arc shapes in a cross section orthogonal to the axial direction X.

[0181] As a metal matrix, by adopting Figure 6 The two arcs shown in (a) or Figure 6As shown in (b), with the same bearing clearance (the inscribed circle of the inner circumferential surface 10b of the metal substrate 10A relative to the outer diameter of the rotating shaft 6), the cross-sectional area of ​​the flow path of the lubricating oil supply path 30 is increased. This allows for an increase in the amount of lubricating oil L supplied from the lubricating oil supply path 30 to the inner circumferential surface 10b.

[0182] Furthermore, in this invention, when the structure of the inner circumferential surface of the metal substrate includes two or three arcs as described above, it is not limited to... Figure 6 (a) or Figure 6 The structure illustrated in (b) is one in which the arcs are evenly arranged along the inner circumferential surface. For example, a structure in which two or three arcs are irregularly arranged along the inner circumferential surface may also be used, or a structure in which at least a portion of the inner circumferential surface is concave in an arc shape, is omitted in detail.

[0183] Furthermore, when the metal substrate adopts a structure with multiple arc-shaped inner circumferential surfaces as described above, a structure that also divides the metal substrate into multiple parts in the circumferential direction can be further adopted. When using the above structure, the division position and number of divisions in the metal substrate are not particularly limited and can be appropriately designed and adopted.

[0184] That is, the metal matrix used in the sliding bearing of the present invention can be constructed in various shapes while taking into account characteristics such as sliding performance and strength.

[0185] In the case of a structure where the metal substrate is divided into multiple parts in the circumferential direction as described above, the thickness of each part of the metal substrate can also be fixed in the entire circumferential direction. The thickness of this part of the metal substrate can also be 0.8 mm or more, or 3 mm or less, similar to the case where the metal substrate is continuous in the circumferential direction.

[0186] On the other hand, the thickness of the partial metal substrate may not be fixed in the circumferential direction. For example, the thickness of the partial metal substrate may be the largest in the circumferential center and decrease towards the circumferential end face. Here, the thickness of the partial metal substrate refers to the radial length of the semi-cylindrical partial metal substrate.

[0187] In addition, such as Figure 2 As shown in example (b), the metal substrate 10A can also be chamfered at the position where the outer peripheral surface 10a is adjacent to the end faces 10c in each axial direction, as needed. Furthermore, as shown in the example, chamfering can also be applied to the position where the inner peripheral surface 10b is adjacent to the end faces in each axial direction, as needed. Additionally, as shown in the example, chamfering can also be applied to the position where the inner peripheral surface 10b is adjacent to the opening 11, as needed.

[0188] Furthermore, in the sliding bearing device for the rotating shaft of the vehicle drive motor of the present invention, in addition to the structure described above, a structure combining a means of forced oil supply to the bearing surface as in conventional sliding bearings is adopted, the discharge and exchange properties of the lubricating oil L are even more superior.

[0189] Industrial availability

[0190] The sliding bearing device for the rotating shaft of a vehicle drive motor according to the present invention can supply lubricating oil to the sliding surface with sufficient quantity without forced oil supply, effectively cooling the sliding surface and its vicinity, while suppressing vibration and noise generation. Therefore, the sliding bearing device of the present invention is very useful, for example, in applications such as electric vehicles.

[0191] Symbol Explanation

[0192] 1. Vehicle drive motor

[0193] 10. Sliding bearing assembly (sliding bearing assembly for the rotating shaft of a vehicle drive motor)

[0194] 10A, 10B, 10C, 10D, 10E Metallic Matrix

[0195] 10a Outer Peripheral Surface

[0196] 10b Inner circumferential surface

[0197] 10c Axial end face

[0198] 11 Opening Road

[0199] 11a One-sided opening

[0200] 11b The opening on the other side

[0201] Sections 12 and 14

[0202] 13a bearing alloy layer

[0203] 13b Backside Metal Layer

[0204] 13c overlay

[0205] 2. Outer shell

[0206] 2A Interior Space (Interior)

[0207] 3 Bearing retaining hole

[0208] Connecting paths 21, 22, 23, 24, and 25

[0209] 21a, 22a, 23a, 24a, 25a Openings on one side

[0210] 21b, 22b, 23b, 24b, 25b The opening on the other side

[0211] 30 Lubricating oil supply line

[0212] 7. Lubricating oil inlet path

[0213] 71 Lubricating oil tank

[0214] 72 Piping

[0215] 73 Oil Nozzle (Injection Unit)

[0216] 4. Stator

[0217] 4A coil

[0218] 5 rotors

[0219] 6 Rotation axis

[0220] 6A Axial Flow Path

[0221] 6a Outer peripheral surface

[0222] 6b Inner circumferential surface

[0223] 61 Inlet Port

[0224] 63 Outlet

[0225] 65 One end

[0226] 64 The other end

[0227] L Lubricating oil

[0228] X-axis (axial direction of the metal matrix)

[0229] S-axis (central axis of the metal matrix)

[0230] B. Minimum diameter (the minimum diameter of the cross section perpendicular to the axis of the open path)

[0231] R is the minimum diameter (the minimum diameter of the cross section perpendicular to the axis of the connecting path).

[0232] W represents the width of the metal substrate.

[0233] G: Direction of gravity

[0234] P Gravity line (the gravity line along the direction of gravity).

Claims

1. A sliding bearing device for the rotating shaft of a vehicle drive motor, It is a device that supports the rotating shaft of a vehicle drive motor as a rotatable sliding bearing, characterized in that, have: A cylindrical metal substrate, the metal substrate including an inner peripheral surface, an outer peripheral surface and two axial end surfaces; The housing has one or more bearing retaining holes for retaining the metal substrate and is capable of internally accommodating at least a portion of the rotating shaft, rotor, and stator of the vehicle drive motor; as well as The lubricating oil inlet section introduces lubricating oil from the outside into the inside of the housing. The metal substrate has one or more openings arranged to communicate between the inner and outer peripheral surfaces. The housing has one or more connecting passages, one opening of which communicates with the opening of the metal substrate on the outer peripheral surface, and the other opening opens to the outside or inside of the housing. A lubricating oil supply path is established between the inner circumferential surface of the metal substrate and the outer circumferential surface of the rotating shaft. This lubricating oil supply path supplies the lubricating oil, which has been introduced into the interior of the housing through the lubricating oil inlet, to the inner circumferential surface, which serves as the sliding surface of the bearing. In the metal substrate, when the central axis of the metal substrate is arranged to intersect a plane perpendicular to the direction of gravity at an angle of less than 10°, the axis of the opening path, measured from the central axis, is arranged within a range of 90° angles relative to the gravity line along the direction of gravity, and the opening path is located near the center of the metal substrate in the axial width direction. The connecting path provided in the outer casing is configured such that the path from one opening to the other opening is generally not oriented in a direction opposite to the direction of gravity. The minimum diameter B of the cross section of the opening path of the metal substrate, which is perpendicular to the axial direction of the opening path, and the minimum diameter R of the cross section of the connecting path of the outer shell, which is perpendicular to the axial direction of the connecting path, satisfy the relationship expressed by the following formula (1): B ≤ 2R (1).

2. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 1, characterized in that, The minimum diameter B of the opening in the metal substrate and the minimum diameter R of the connecting path in the outer shell satisfy the relationship expressed by the following formula (2): B ≤ R (2).

3. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 1 or 2, characterized in that, The axis of the opening in the metal substrate is arranged within a range of 60° relative to the gravity line along the direction of gravity, measured from the angle centered on the central axis.

4. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 1 or 2, characterized in that, The axis of the opening in the metal substrate is arranged at an angle of 45° relative to the gravity line along the direction of gravity, with the central axis as the center.

5. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 1 or 2, characterized in that, The lubricating oil inlet sprays or drips, or supplies the lubricating oil in a swirl manner, toward the rotating shaft of the vehicle drive motor disposed inside the housing.

6. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 5, characterized in that, The lubricating oil inlet includes at least an oil injection unit disposed inside the housing, through which the lubricating oil is supplied by spraying it toward the rotating shaft of the vehicle drive motor.

7. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 5, characterized in that, The lubricating oil inlet includes at least a gutter-like component disposed inside the housing and introducing the lubricating oil from the outside. The gutter-like component is positioned on the side opposite to the direction of gravity when viewed along the rotation axis of the vehicle drive motor, and has one or more outlets configured to allow the lubricating oil to drip onto the rotation axis and the rotor, or to be supplied in a drip manner.

8. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 5, characterized in that, The lubricating oil inlet includes at least a lubricating oil supply pipe, which is disposed inside the housing and introduces lubricating oil from the outside. The lubricating oil supply pipe is positioned on the side opposite to the direction of gravity when viewed along the rotation axis of the vehicle drive motor, and has one or more outlets positioned to supply the lubricating oil to the rotation axis and the rotor by dripping or in a hanging manner.

9. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 1 or 2, characterized in that, The rotating shaft of the vehicle drive motor is hollow, and the internal space of the rotating shaft is configured as a central flow path for the lubricating oil to circulate. Furthermore, the rotating shaft includes: an inlet located at at least one end for introducing lubricating oil from the lubricating oil inlet into the shaft flow path; and an outlet opening from the shaft flow path to the outer peripheral surface of the rotating shaft, through which the lubricating oil introduced into the shaft flow path flows out by centrifugal force accompanying the rotation of the rotating shaft, thereby supplying the lubricating oil in a manner that allows it to be suspended on the outer peripheral surface of the rotating shaft.

10. The sliding bearing device for the rotating shaft of a vehicle drive motor according to claim 1 or 2, characterized in that, The opening on the other side of the communication path of the housing opens into the interior of the housing. The lubricating oil supplied to the inner circumferential surface of the metal substrate is discharged into the interior of the housing and stored through the opening and the connecting passage. Furthermore, a portion of the remaining lubricating oil supplied from the lubricating oil inlet to the rotating shaft of the vehicle drive motor falls into the housing and is stored there. Furthermore, a portion of the lubricating oil stored inside the housing splashes out as the rotor and rotating shaft of the vehicle drive motor rotate, thereby supplying it again to the inner circumferential surface of the metal substrate, thus circulating the lubricating oil.

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