JP2019119360A - Wheel bearing device and vehicle including the same - Google Patents

Abstract

To propose a wheel bearing device which includes a power device and suppresses heat generated when large current flows therethrough to a low level even in the power device with a limited dimension by reducing temperature rise caused by the heat generated by a coil with circulation of a cooling oil.SOLUTION: A wheel bearing device includes a wheel bearing 2 and a motor 3 serving as a power device. The motor 3 has: a stator 18 attached to a fixed ring 4 of the wheel bearing 2; and a rotor 19 attached to a rotary ring 5. A case 23 serving as an outer shell of the motor 3 and the wheel bearing 2 forms a sealed space filled with lubrication oil therein. In the wheel bearing device, circulation power generation means, such as an impeller 74, which circulates cooling oil in a circulation oil passage provided within the case 23 is provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wheel bearing device having a function of giving a traveling driving force to an automobile, a vehicle provided with the wheel bearing device, and a power unit thereof.

  An in-wheel motor incorporating a motor inside the wheel contributes to the improvement of the fuel efficiency of the vehicle through the generation of power when driving and decelerating the vehicle. However, it is difficult to fit a high-power motor into the wheel, and the components around the wheel also had to be changed from conventional products. For example, in Patent Document 1, as a direct drive type in-wheel motor system, a rotor of a motor is installed in a hub portion via a hollow cylindrical plate, and a stator of the motor is mounted around the foot of a vehicle via a buffer mechanism. It has been proposed to be attached to frame parts.

JP 2005-333706 A

  In the in-wheel motor as described above, since the brake disc is positioned on the inner diameter side of the annular motor, the brake caliper interferes with the motor, making it difficult to install the brake. Then, in order to solve this problem, as shown in FIG. 14, a generator which is smaller in diameter and smaller in size than the outer peripheral portion 12b of the brake rotor 12 and which assists traveling drive and generates electric power by the motor 3 which can be stored in the wheel. A bearing device for wheeled wheels was proposed. The wheel bearing 2 in the generator equipped wheel bearing of this proposal example is an inner ring rotation, and the stator of the motor 3 is provided on the outer periphery of the fixed ring which is the outer ring 4. A rotor 19 of the motor 3 is provided.

The generator-equipped wheel bearing device of the above-described example can be accommodated in the wheel, and the components around the wheel can be used as they are in the conventional configuration in which the wheel bearing device having no power generation or drive function is installed. There is. However, due to the limitation of the motor size, the motor output can not be increased, and the fuel efficiency improvement effect by the assistance of the driving force and the power recovery at the time of the braking operation is small, and can not meet the high fuel efficiency target in recent automobile industry.
Although it is conceivable to increase the current supplied to the winding coil 18b of the stator 18 in order to increase the motor output, the heat generation of the winding coil 18b is increased by the winding coil and motor components such as the winding coil 18b and the permanent magnet 19c And bearing seal parts may increase in temperature beyond the allowable temperature. As a result, in order to prevent excessive temperature rise, the motor current must be limited, and a necessary and sufficient motor output can not be obtained.

  The present invention solves the above-mentioned problems, and an object thereof is a power unit whose size is limited by providing a power unit and reducing the temperature rise due to the heat generation of its coil by circulating the cooling oil. It is an object of the present invention to provide a bearing device for a wheel, a vehicle, and a power unit thereof in which heat generation at the time of a large current can be suppressed to a low level.

The generator-equipped wheel bearing apparatus according to the present invention includes a fixed wheel, a wheel bearing having a rotary wheel rotatably supported on the fixed wheel via a rolling element and on which a vehicle wheel is mounted, and mounted on the fixed wheel A wheel bearing device comprising: a power unit having a fixed stator and a rotor attached to the rotating wheel,
A clearance between the stator and the rotor formed between the stator and the rotor, a pair of coil end accommodation spaces formed in the generator around the coil ends on both sides of the stator, and A case is provided for sealing the bearing end adjacent space located axially adjacent to each other,
A circulation force generating means is provided for circulating the cooling oil in the circulation oil passage provided in the case.

  According to this configuration, the cooling oil is circulated in the circulation oil passage by the circulation force of the circulation force generation means, whereby the winding coil of the stator is cooled. The heat of the cooling oil in the circulating oil path is dissipated by heat conduction to the vehicle body from the location where the case contacts the vehicle body via the frame frame parts such as knuckles, etc., and it is air cooled and kept at low temperature. . Thus, since the winding coil of the stator is cooled, even in the case of a power unit whose size is limited, heat generation at a large current is suppressed to a low level, and the problem of excessive temperature rise does not occur.

In the bearing device for a wheel according to the present invention, a communication oil passage passing through the inside of the fixed wheel is provided, and the space adjacent to the bearing end, the communication oil passage, one of the coil end accommodation spaces, The circulation oil passage may be formed which sequentially circulates through the stator-rotor gap, the other coil end accommodation space, and the space adjacent to the bearing end.
In this configuration, cooling oil flows around the coil end, and the coil end is directly cooled by the cooling oil, so that the cooling efficiency is good.

In the wheel bearing device of the present invention, the circulating force generation means may be configured to circulate the cooling oil by relative rotation of the rotating wheel and the fixed wheel of the wheel bearing.
In this configuration, no separate drive source is required to circulate the cooling oil.

In the wheel bearing device of the present invention, the wheel bearing is an inner ring rotating type in which the rotating wheel is an inner ring, the power unit is an outer rotor type, and the case is fixed to the fixed ring. It may have a fixed case and a rotating case fixed to the rotating wheel and the rotor.
When the rotating case is fixed to the rotor, the case of the generator does not have to be provided separately from the case, and the structure can be made compact. Moreover, since it is an outer rotor type and a moment generation | occurrence | production position turns into a radial position when using a motor for the said generator, big torque is obtained.

In the bearing device for a wheel according to the present invention, the fixed wheel has a fixed wheel main body having a raceway surface for rolling the rolling elements, and an intermediate member which is externally fitted to the fixed wheel main body and the stator is attached to the outer periphery. The communication fluid passage may be formed in the intermediate member.
If the fixed ring of the wheel bearing is a member having a raceway surface for rolling element rolling, it is difficult to attach the stator of the power unit and to form the circulating oil path. However, when the intermediate member is provided to attach the stator and form the communication oil passage, the communication oil passage can be easily formed.
In addition, when the whole of the said fixed ring is used as integral components, a number of parts may be small and an assembly man-hour will also be reduced.

In the bearing apparatus for a wheel according to the present invention, the circulating force generating means may include an impeller located in the space adjacent to the bearing end and coaxially connected to the rotating wheel.
With an impeller, the lubricating force of the circulating oil passage can be efficiently obtained, and by connecting the rotating wheel of the wheel bearing directly to the impeller, the impeller can be rotated, and the configuration of the circulating force generation means becomes simple. .
In addition, when providing an impeller, you may use together a thing different from an impeller as a circulation force generation | occurrence | production means.

In the wheel bearing device of the present invention, a secondary cooling device for cooling the cooling oil flowing through the circulating oil passage may be provided in the middle of the circulating oil passage.
Although the secondary cooling device complicates the configuration, the temperature rise of the cooling oil passage can be suppressed to a lower level to further reduce the temperature rise of the winding coil.

In the wheel bearing device of the present invention, the circulation force generation means may include a pump that enhances the circulation force of the cooling oil in the circulation oil passage.
By having another pump, the cooling oil can be lubricated at a higher speed, and the temperature rise of the winding coil can be suppressed more efficiently.

In the bearing apparatus for a wheel according to the present invention, the pressure generated by the relative rotation of the rotor and the stator on the circumferential surface constituting the stator-rotor gap in one or both of the rotor and the stator as the circulating force generating means. It may have a thread groove that produces a gradient.
When the groove is formed on the peripheral surface of one or both of the rotor and the stator forming the stator-rotor gap, the rotation of the rotor generates a pressure gradient in the stator-rotor gap cooling oil. For this reason, it is possible to configure the circulation force generation means with a simple configuration. The screw groove may be used in combination with other circulating force generating means such as an impeller.

In the wheel bearing device of the present invention, the wheel bearing may be a bearing that supports a driven wheel that is mechanically disconnected from the main drive source of the vehicle.
In this configuration, the driving force of the power unit can be applied to the driven wheel, and the driving force of the driven wheel can be added to the driving force of the main drive source to drive the vehicle.

In the wheel bearing device of the present invention, the wheel bearing may be a bearing that supports a driving wheel mechanically coupled to a main drive source of the vehicle.
In this configuration, the drive wheel can be driven by adding the drive force of the power unit to the drive force of the main drive source.

A vehicle according to the present invention includes the wheel bearing device of any of the above-described configurations according to the present invention.
According to the vehicle of this configuration, the effects described for the wheel bearing device of the present invention can be obtained.

The power plant according to the present invention is a power plant comprising a motor generator installed in a wheel bearing,
A stator attached to a fixed wheel of the wheel bearing, and a rotor attached to a rotating wheel of the wheel bearing;
The power unit is an outer rotor type in which the stator is located on the outer periphery of the wheel bearing and the rotor is located radially outward of the stator.
The entire power unit is smaller in diameter than an outer peripheral portion of a brake rotor attached to the rotary wheel, which is a portion to which the brake caliper is pressed, and is provided on the outboard side of the rotary wheel in the power unit. The entire portion except the mounting portion to the hub flange is located in an axial range between the hub flange and a vehicle mounting surface on the inboard side of the wheel bearing,
A clearance between the stator and the rotor formed between the stator and the rotor, a pair of coil end accommodation spaces formed in the generator around the coil ends on both sides of the stator, and A case is provided for sealing the bearing end adjacent space located axially adjacent to each other,
A circulation force generating means is provided for circulating the cooling oil in the circulation oil passage provided in the case.
According to the power unit of this configuration, the wheel bearing is installed in the wheel bearing, and the above-described operation and effect can be obtained for the wheel bearing of the present invention.

A wheel bearing device according to the present invention comprises a fixed wheel, a wheel bearing having a rotary wheel rotatably supported by the fixed wheel via a rolling element and on which a vehicle wheel is mounted, and a stator mounted on the fixed wheel And a power unit having a rotor attached to the rotating wheel, wherein the bearing assembly for a wheel includes a stator-rotor gap formed between the stator and the rotor, in an axially extending position on both sides of the stator. There is provided a case for sealing a pair of coil end accommodation spaces formed around the coil end, and a bearing end adjacent space located adjacent to the axial direction of the rotating wheel on the side frame component side, and in the case As a circulating force generating means for circulating the cooling oil in the circulating oil passage provided is provided,
Even in a power unit whose size is limited, the heat generation at the time of a large current can be suppressed to a small level, and a large current can be continuously supplied to the power unit.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the bearing apparatus for wheels which concerns on 1st embodiment of this invention, and its periphery part. It is a sectional view of the bearing device for the same wheels. It is a perspective view of the impeller of the bearing apparatus for the same wheels. It is a partial expanded sectional view of the stator of the bearing apparatus for the same wheels. It is sectional drawing of the bearing apparatus for wheels which concerns on other embodiment of this invention. It is sectional drawing of the bearing apparatus for wheels which concerns on other embodiment of this invention. It is sectional drawing of the bearing apparatus for wheels which concerns on other embodiment of this invention. It is sectional drawing of the bearing apparatus for wheels which concerns on other embodiment of this invention. It is sectional drawing of the bearing apparatus for wheels with a generator which concerns on further another embodiment of this invention. It is a fragmentary sectional view of the rotor of the bearing apparatus for wheels with a generator which concerns on other embodiment of this invention. It is a block diagram which shows the conceptual structure of the system for vehicles using the bearing apparatus for wheels with a generator which concerns on said arbitrary embodiment. It is a power supply system figure used as an example of the vehicles carrying the system for vehicles. It is a block diagram which shows the conceptual structure of the system for other vehicles using the bearing apparatus for wheels with a generator. It is sectional drawing of the proposal example of the bearing apparatus for wheels with a generator.

  A first embodiment of the invention will be described in conjunction with FIGS. 1 to 4. The wheel bearing device 1 includes a wheel bearing 2 and a motor 3 which is a motive power device including a motor generator having a power generation function.

<About wheel bearing 2>
The wheel bearing 2 has an outer ring 4 which is a fixed ring, rolling elements 6 in double rows, and an inner ring 5 which is a rotating ring. The inner ring 5 is rotatably supported by the outer ring 4 via the rolling elements 6 in double rows. The outer ring 4 is composed of an outer ring main body 4a having a raceway surface and an intermediate member 4b on the outer periphery thereof. The inner ring 5 has a hub flange 7 at a location protruding toward the outboard side in the axial direction with respect to the outer ring 4. The inner ring 5 comprises, in the illustrated example, a hub ring 5a having the hub flange 7 and a partial inner ring 5b fitted on the outer periphery of the inboard end of the hub ring 5a. The outer ring 4 is attached by bolts or the like to an undercarriage frame part 8 such as a knuckle of a suspension system of a vehicle via a wheel bearing 2 and a case 23 serving as an outer shell of the motor 3 to support the weight of the vehicle. In this specification, when the wheel bearing device 1 is mounted on a vehicle, the side closer to the outside in the vehicle width direction of the vehicle is called the outboard side, and the side closer to the center in the vehicle width direction is in Called the board side.

  The rim 11 of the wheel 10 and the brake rotor 12 are attached to the side surface on the outboard side of the hub flange 7 by the hub bolt 13 in a state where the rim 11 and the brake rotor 12 overlap in the axial direction. A tire (not shown) is attached to the outer periphery of the rim 11.

<About the brake 17>
The brake 17 is a friction brake provided with a disc type brake rotor 12 and a brake caliper 22. The brake rotor 12 is formed of an annular and flat disk-like portion 12a overlapping the hub flange 7 and an outer peripheral portion 12b. The outer peripheral portion 12 includes a cylindrical portion 12ba extending from the outer periphery of the disk portion 12a to the outer peripheral side of the motor 3 and an outer diameter side flat portion 12bb extending radially outward from the tip of the cylindrical portion 12ba. The brake rotor 12 is made of, for example, a pressed product of a steel plate.

  The brake caliper 22 has a pair of friction pads 22 a sandwiching the outer diameter side flat plate portion 12 bb of the outer peripheral portion 12 b of the brake rotor 12. The brake caliper 22 is attached to the underbody frame part 8. The brake caliper 22 may be either hydraulic or mechanical, or may be motor.

<About motor 3>
The motor 3 is a drive assisting electric motor capable of rotationally driving the wheel 10 by being supplied with power, and is used as a generator at the time of regenerative braking. The motor 3 has a stator 18 attached to the outer peripheral surface of the outer ring 4 and a rotor 19 attached to the hub flange 7 of the inner ring 5. The motor 3 in the illustrated example is an outer rotor type IPM (Interior Permanent Magnet Motor) synchronous motor. Moreover, SPM (Surface Permanent Magnet Motor) synchronous motor can also be used. In addition, various types such as a switched reluctance motor (abbreviation: SR motor), an induction motor (induction motor; abbreviation: IM), and the like can be adopted as the motor 3. In the synchronous motor, each type of distributed winding and concentrated winding can be adopted as a winding type of the stator 18.

  The whole of the motor 3 is smaller in diameter than the outer peripheral portion 12 b of the brake rotor 12. The motor 3 is substantially entirely located in the axial range between the hub flange 7 and the mounting surface S of the frame part 8 except for the mounting portion to the hub flange 7 and the fixing case 23 a of the case 23 described later.

The stator 18 of the motor 3 has a core 18a and a coil 18b wound around teeth 18aa (see FIG. 4) of the core 18a. A portion axially projecting from the core 18a of the coil 18b constitutes a coil end 18ba. The coil 18 b is connected to the wire 60.
The motor rotor 19 includes a lateral cup-shaped rotation case 23b serving as a motor case, a magnetic body 19b provided on the inner periphery of the rotation case 23b, and a permanent magnet (not shown) incorporated in the magnetic body 19b. The bottom of the rotation case 23 b is attached to the hub flange 7. The center of the bottom of the rotating case 23 b has a central opening that allows the outboard side portion to project beyond the hub flange 7 of the inner ring 5. The rotation case 23b may be attached to the hub flange 7 by fastening or fixing the bolt 13 or by fitting, welding, bonding or the like to the outer peripheral surface of the hub flange 7. The outer peripheral surface of the rotation case 23 b is close to the inner peripheral surface of the cylindrical portion 12 b of the brake rotor 12.

<About Case 23>
The wheel bearing 2 and the motor 3 are entirely covered by a case 23. The case 23 is composed of the rotating case 23b and the fixed case 23a. The fixed case 23a closes the inboard side end of the cup-shaped rotation case 23b, and the inboard side end of the outer ring 4 which is the fixed ring of the wheel bearing 2 is fixed to the inner side surface. Specifically, the inboard end of the intermediate member 4b of the outer ring 4 is fixed. The space between the outer peripheral portion of the fixed case 23a and the opening edge of the rotating case 23b is sealed by an annular seal member 25, and the entire internal space of the case 23 becomes a lubricating oil filled space. The sealing member 25 is a member for sealing the gap between the fixed case 23a and the rotating case 23b in a relatively rotatable manner. For example, the sealing member 25 may be a slinger attached to one of the fixed case 23a and the rotating case 23b; And a sealing lip (not shown) that is in sliding contact with the slinger.
The wire 60 extending from the coil end 18ba of the motor 3 is inserted into the wire insertion hole provided in the fixed case 23a and pulled out of the case 23, and seals the gap between the wire insertion hole and the wire at the outer opening. A seal 61 is provided.

<About seal structure>
A rotor end ring member 27 is attached to the inner periphery of the inboard end of the rotation case 23b, and the seal between the rotor end ring member 27 and the fixed case 23a is made by the seal member 25. The rotor end ring member 27 doubles as a positioning member in the axial direction of the permanent magnet contained in the magnetic body 19 b. A seal member 28 such as an O-ring is interposed between the outer peripheral surface of the rotor end ring member 27 and the inner peripheral surface of the rotation case 23b.
The fixed case 23 a is fixed to the undercarriage frame part 8, whereby the entire wheel bearing device 1 is fixed to the undercarriage frame part 8.

<About the rotation sensor>
A rotation sensor 63 for detecting the rotation of the inner ring 5 is provided on the inboard side of the inner ring 5 of the wheel bearing 2. The rotation sensor 63 comprises a resolver or a magnetic encoder. The rotation sensor 63 is composed of a rotating detected portion 63a and a sensor portion 63b that detects the detected portion 63a. The to-be-detected portion 63 b is formed in an annular shape, and is fitted to the outer periphery of the rotation sensor shaft 64 coaxially mounted on the inboard side surface of the inner ring 5 with the inner ring 5. It is attached to 64. The sensor portion 63b is formed in an annular shape in which the detection surface faces the outer peripheral surface of the detected portion 63b, and is attached to a flange portion projecting on the inner periphery of the intermediate member 4b of the outer ring 4 by a sensor portion fixing bolt 91.

<About cooling structure>
The intermediate member 4b of the outer ring 4 has a thick-walled cylindrical shape extending inward from the outer ring main body 4a, and communication oil passages 66 extending in the axial direction are provided at a plurality of locations in the circumferential direction inside There is. One end of the communication oil passage 66 opens at the end face on the outboard side of the intermediate member 4b, and the other end opens at the inner circumferential surface near the inboard end of the intermediate member 4b. Further, within the thickness of the fixed case 23a, case wall communication paths 67 communicating with the inner circumferential surface from the surface facing the stator 18 are formed at a plurality of locations in the circumferential direction.
As a part constituting the case internal space of the case 23, a stator-rotor gap 68 generated between the stator 18 and the rotor 19 of the motor 3, coil end accommodation spaces 69, 70 on both sides of the stator 18, and wheels There is a bearing end adjacent space 71 located on the inboard side of the inner ring 5 of the bearing 2. The stator-rotor gap 68 includes a coil-to-coil gap 72 generated between adjacent teeth 18 aa of the core 18 a.

  These spaces are provided with the communication oil passage 66 and the case wall communication passage 67 so that the stator / rotor gap 68, the inboard coil end accommodation space 70, the case inner wall oil passage 67, the bearing end The adjacent space 71, the communication oil passage 66, and the coil end accommodation space 69 on the outboard side constitute a circulation oil passage 73 that circulates in this order. A cooling oil for motor cooling is filled in the case internal space that constitutes the circulating oil passage 73. This cooling oil also serves as lubricating oil for the wheel bearing 2 in this embodiment, but sealing members (inboard and outboard side openings in the bearing space between the outer ring 4 and the inner ring 5 of the wheel bearing 2) The cooling oil may be dedicated to cooling by providing grease (not shown) and filling the bearing space.

<Regarding Circulation Force Generating Means, Impeller 74>
A plow 74 is provided in the case 23 as a circulating force generating means for circulating the cooling oil of the circulating oil passage 73. The impeller 74 is coaxially fixed to the inner ring 5 on the inboard side of the inner ring 5 at the end face of the detected portion fixing bolt sensor fixing bolt 65. The opening on the bearing end adjacent space 71 side of the communication oil passage 66 is at an axial position facing the outer periphery of the impeller 74.
The impeller 74, as shown in FIG. 3, includes a truncated cone-shaped central portion 74a and a plurality of blades 74b provided circumferentially along the outer periphery of the central portion 74a. The central portion 74a has a concave shape as shown in FIGS. 1 and 2 in the shape of the cross section including the axial center.

  In the cooling structure of this embodiment, since the cooling oil directly contacts the winding coil 18b, the insulating coating film such as varnish covering the winding coil 18b may be deteriorated by the cooling oil to cause insulation failure. Therefore, it is preferable to use an insulating material that is not deteriorated by the cooling oil. It is preferable to use a phenol-based or alkyd-based insulating varnish material as the insulating coating film that is less likely to cause such deterioration, and the problem of the leading edge coating film deterioration can be solved from this. The same applies to the following embodiments.

<Operation and effect of the first embodiment>
The circulation operation of the cooling oil will be described.
While the vehicle is traveling, the rotor 19 and the rotation sensor rotation shaft 64 of the wheel bearing device 1 rotate as the wheels rotate. The rotation of the impeller 74 integrally formed with the rotation sensor rotation shaft 64 causes cooling oil to be sent to the coil end accommodation space 69 on the hub flange 7 side through the communication oil passage 66. Further, the cooling oil flows to the stator / rotor gap 68 and the coil end accommodation space 70, and is returned to the impeller 74 in the bearing end adjacent space 71 through the in-case flow path 67.
Further, as the rotor 19 of the motor 3 rotates, the cooling oil is dragged to the inner peripheral surface of the rotor 19 and stirred around the rotation axis, and the winding coil 18b is uniformly cooled.

  In this cooling structure, the cooling oil is in direct contact with the winding coil 18b which is the heat source, so the cooling effect is large. In the conventional cooling method in which cooling is performed via a member provided with a coolant flow channel, the structure of the flow channel is complicated, and it is difficult to achieve compactness. In addition, although measures such as infiltrating a heat dissipation resin for improving heat dissipation into coil magnetic pole portions adjacent to each other in the circumferential direction of the winding coil 18b are indispensable, in the cooling structure of this embodiment, the heat dissipation There is no need to penetrate the resin. Furthermore, since the cooling oil is circulated by using the rotation of the wheel in operation, a new power source for rotating the impeller 74 is not required.

As described above, by cooling the heat generated by supplying current to the winding coil 18b and suppressing the heat generation of the winding coil 18b, a large current can be continuously supplied to the motor 3 to improve fuel consumption. It is possible to generate a motor output that can contribute sufficiently. The structure for circulating the cooling oil also contributes to the lubrication of the wheel bearing 2.
The motor 3 generates electric power by regenerative braking at the time of braking of the vehicle, but the heat generation at the time of electric power generation is suppressed in the same manner as at the time of driving, and sufficient power generation can be performed.
Further, in the wheel bearing device 1 of this embodiment, since the whole of the motor 3 has a diameter smaller than that of the outer peripheral portion of the brake rotor 12, the outer peripheral portion of the brake rotor and the wheel bearing produced in a general vehicle The auxiliary power unit can be installed by efficiently utilizing the space between them.

<Embodiment of FIG. 5>
Other embodiments will be described in conjunction with FIGS. 5 to 10. In these embodiments, other than the matters particularly described, the second embodiment is the same as the first embodiment described above with reference to FIGS. 1 to 4.

<Embodiment of FIG. 5>
In the above-described embodiment, the outer ring of the wheel bearing 2 is divided and the intermediate member having the communication oil passage is used for easy processing of the communication oil passage of the cooling oil, as shown in FIG. The communication wheel passage 66 may be provided by integrally forming the outer ring 4 of the wheel bearing 2. The integral structure can simplify the structure.

<Embodiment of FIG. 6>
In the first embodiment shown in FIGS. 1 to 4, in order to further increase the cooling efficiency, a secondary cooling device 75 may be added as shown in FIG. The secondary cooling device 75 includes a secondary coolant circulation path 76 having a portion 76 a along the case wall communication path 67 in the circulation oil path 73 and a pump 77 for circulating the coolant in the secondary coolant circulation path 76. And consists of. The pump 77 is driven by a motor (not shown) different from the motor 3. The coolant in the secondary coolant circulation path 76 obtained by cooling the lubricating oil in the circulation oil path 73 by heat exchange is cooled by heat conduction to the vehicle body and air cooling while flowing in the secondary coolant circulation path 76. Ru.
The presence of the secondary cooling device 75 complicates the configuration, but can further suppress the temperature rise of the cooling oil to further reduce the temperature rise of the winding coil 18b.

<Embodiment of FIG. 7>
Further, in the first embodiment shown in FIGS. 1 to 4, instead of providing the impeller 74, a pressure pump 78 is provided as a circulation force generating means, and the circulation oil passage 73 and the pressure pump 78 are combined with the suction passage 79 and the discharge passage. You may connect by 80. The discharge passage 80 opens at the axial center of the inboard side wall surface of the space 71 adjacent to the bearing end, and the suction passage 79 is connected to the coil end accommodation space 70 via another oil passage 81 provided in the fixed case 23a. It is done. The pressure pump 78 is driven by another motor (not shown).
In the case of this configuration, as compared with the case where the pump 74 is operated by the impeller 74 of FIG. 2, the cooling oil can be circulated at a higher speed by providing the high-performance pressure pump 78, and the cooling efficiency is increased.

<Embodiment of FIG. 8>
In the embodiment of FIG. 8, in the first embodiment, a screw groove 82 is provided on the outer peripheral surface of the core 18 a of the stator 18 which constitutes the stator-rotor gap 68 to constitute a screw pump.
As the circulating force generating means, a screw pump formed by the screw groove 82 is added to the impeller 74 and provided.
In this configuration, a pressure gradient can be generated in the stator-rotor gap 68 by the rotation of the rotor of the motor 3 to increase the circulation speed. Thereby, the cooling efficiency of the winding coil 18b is further improved.

<Embodiment of FIG. 9>
In the embodiment of FIG. 9, the screw groove 82 is provided on the inner peripheral surface of the rotor 19 instead of the configuration in which the screw groove 82 is provided on the outer peripheral surface of the stator 18 in the embodiment of FIG.
Also in this configuration, a pressure gradient can be generated in the stator-rotor gap 68 by the rotation of the rotor 19 of the motor 3 to increase the circulation speed. Thereby, the cooling efficiency of the winding coil 18b is further improved.

<Other Embodiments>
The embodiment of FIG. 8 and the embodiment of FIG. 9 may be used in combination. That is, the screw groove 22 may be provided on both the outer peripheral surface of the stator 18 and the inner peripheral surface of the rotor 19 that constitute the stator-rotor gap 68.
In the SPM synchronous motor of FIG. 10, the gap 82A between the permanent magnets 19c arranged in the circumferential direction on the inner peripheral surface of the magnetic body 19b of the rotor 19 may be inclined with respect to the axial direction. This also generates a pressure gradient in the stator-rotor gap 68.

<About Control System of Vehicle 30>
FIG. 11 is a block diagram showing a conceptual configuration of a vehicle system using the wheel bearing device 1 according to any one of the embodiments.
In the vehicle system, a wheel bearing apparatus 1, in a vehicle having a driven wheel 10 _B is the main drive source 35 mechanically unconnected, is mounted against the driven wheel 10 _B. Wheel bearing 2 in the bearing device for a wheel 1 (FIG. 1) is a bearing supporting the driven wheel 10 _B.

The main drive source 35 is an internal combustion engine such as a gasoline engine or a diesel engine, or a motor generator (electric motor), or a hybrid drive source combining both. The "motor generator" refers to an electric motor capable of generating power by rotation. In the illustrated example, the vehicle 30 is a front wheel drive car whose front wheels are drive wheels 10 _A and rear wheels are driven wheels 10 _B, and the main drive source 35 is an internal combustion engine 35 a and a motor generator 35 b on the drive wheels side. A hybrid vehicle (hereinafter sometimes referred to as “HEV”).

Specifically, it is a mild hybrid type in which the motor generator 35b on the drive wheel side is driven by a medium voltage such as 48V. Hybrids can be broadly divided into Strong Hybrids and Mild Hybrids, but Mild Hybrids, whose main drive source is an internal combustion engine, is a type that mainly assists driving with a motor when starting or accelerating. In the (electric car) mode, it can be distinguished from the strong hybrid because normal travel can be performed for a while but can not be performed for a long time. Internal combustion engine 35a of the example of the figure, is connected to the drive shaft of the drive wheel 10 _A via the clutch 36 and speed reducer 37, the motor generator 35b of the driving wheel is connected to a reduction gear 37.

System for a vehicle includes a motor 3 for traveling aid for rotating driving of the driven wheels 10 _B, the individual control means 39 for controlling the motor 3, the drive and the individual control means 39 provided in the upper ECU40 And an individual motor generator command means 45 for outputting a command for performing control of regeneration. The generator 3A is connected to the storage means. The storage means may be a battery (storage battery) or a capacitor, a capacitor, etc. The type and mounting position on the vehicle 30 are not limited. In this embodiment, the low voltage battery 50 mounted on the vehicle 30 and The medium voltage battery 49 of the medium voltage battery 49 is used.

The driven wheel motor 3 is a direct drive motor that does not use a transmission. The motor 3 also acts as a generator for converting kinetic energy of the vehicle 30 into electric power.
Since the motor 3 has the rotor 19 attached to the inner ring 5 (FIG. 1) which is a hub wheel, when a current is applied to the motor 3, the inner ring 5 (FIG. 1) is rotationally driven. Regenerative power can be obtained by loading. The drive voltage or regenerative voltage for driving the motor 3 to rotate is 100 V or less.

The host ECU 40 is a unit that performs integrated control of the vehicle 30, and includes a torque command generation unit 43. The torque command generation unit 43 generates a torque command in accordance with signals of operation amounts respectively input from an accelerator operation unit 56 such as an accelerator pedal and a brake operation unit 57 such as a brake pedal. The vehicle 30 includes an internal combustion engine 35a and the drive wheel of the motor 35b as the main drive source 35, and because with the two motors 3, 3 for driving two driven wheels ₁₀ B, 10 _B, respectively, the torque command Is distributed to the respective drive sources (35a, 35b, 3, 3) according to the rules defined in the respective drive sources (35a, 35b, 3, 3).

  The torque command for the internal combustion engine 35a is transmitted to the internal combustion engine control means 47, and is used for valve opening control etc. by the internal combustion engine control means 47. A torque command to the drive wheel side generator motor 35b is transmitted to the drive wheel side motor generator control means 48 and executed. Torque commands for the driven wheels 3, 3 are transmitted to the individual control means 39, 39. The part of the torque command distribution means 44 to be output to the individual control means 39, 39 is referred to as an individual motor generator command means 45. The individual motor generator command means 45 also has a function of giving to the individual control means 39 a torque command serving as a command of a braking force with which the motor 3 shares braking by regenerative braking in response to the signal of the operation amount of the brake operation means 57. Prepare.

  The individual control means 39 is an inverter device, and an inverter 41 for converting DC power of the medium voltage battery 49 into three-phase AC voltage, and a control unit 42 for controlling the output of the inverter 41 by PWM control etc. Have. The inverter 41 includes a bridge circuit (not shown) such as a semiconductor switching element or the like, and a charging circuit (not shown) for charging the medium voltage battery 49 with the regenerative power of the motor 3. Although the individual control means 39 is provided separately for the two motors 3 and 3, it may be housed in a single housing, and the control unit 42 may be shared by both individual control means 39 and 39. .

  FIG. 12 is a power supply system diagram as an example of a vehicle equipped with the vehicle system shown in FIG. In the example of the figure, the low voltage battery 50 and the medium power battery 49 are provided as the battery, and both the batteries 49 and 50 are connected via the DC / DC converter 51. Although there are two motors 3, one is representatively shown. The motor 35b on the drive wheel side of FIG. 15 is connected to the medium power system in parallel with the motor 3 on the driven wheel side, although not shown in FIG. A low voltage load 52 is connected to the low voltage system, and a medium voltage load 53 is connected to the medium voltage system. There are a plurality of low voltage loads 52 and a plurality of medium voltage loads 53, but one is representatively shown.

  The low voltage battery 50 is a battery generally used in various automobiles as a power supply of a control system or the like, and is, for example, 12 V or 24 V. The low voltage load 52 includes basic components such as a starter motor of the internal combustion engine 35a, lights, a host ECU 40, and other ECUs (not shown). The low voltage battery 50 may be referred to as an auxiliary battery for electrical equipment accessories, and the medium voltage battery 49 may be referred to as an auxiliary battery for an electric system or the like.

  The medium voltage battery 49 has a voltage higher than that of the low voltage battery 50 and lower than a high voltage battery (100 V or more, for example, about 200 to 400 V) used in a strong hybrid vehicle etc. It is a voltage that does not cause a problem, and a 48V battery used in recent years for mild hybrids is preferable. A medium voltage battery 49 such as a 48V battery can be mounted relatively easily on a vehicle equipped with a conventional internal combustion engine, and can reduce fuel consumption by power assist and regeneration with electric power as a mild hybrid.

  The medium voltage load 53 of the 48V system is the accessory component, and is a power assist motor which is the motor 3 on the drive wheel side, an electric pump, an electric power steering, a supercharger, an air compressor, or the like. By configuring the load of accessories with a 48V system, although the power assist output is lower than that of high voltage (100V or higher strong hybrid vehicles etc.), the risk of electric shock to occupants and maintenance workers can be reduced. it can. Since the insulation coating of the wire can be thinned, the weight and volume of the wire can be reduced. Further, since a large amount of power can be input / output with a current amount smaller than 12 V, the volume of the motor or generator can be reduced. From these things, it contributes to the fuel consumption reduction effect of vehicles.

  The vehicle system is suitable for accessory parts of such mild hybrid vehicles, and is applied as a power assist and a power regeneration part. Although CMGs, GMGs, and belt-driven starter motors (none of which are shown) may be employed conventionally in mild hybrid vehicles, all of them are power assists for internal combustion engines or power devices. Or because it regenerates, it is affected by the efficiency of the transmission device and speed reducer.

  On the other hand, since the vehicle system of this example is mounted on the driven wheel 10B, it is separated from the main drive source such as the internal combustion engine 35a and the motor (not shown). The kinetic energy of the vehicle body 1 can be used directly. In addition, when CMG, GMG, a belt drive type starter motor, etc. are mounted, it is necessary to consider considering from the design stage of the vehicle 30, and it is difficult to retrofit, but the system for this vehicle that fits in the driven wheel 10B The motor 3 can be mounted with the same number of steps as part replacement even if it is a complete vehicle, and a system of 48 V can be configured even for a complete vehicle with only the internal combustion engine 35a. If another auxiliary drive motor 35b is mounted on the vehicle equipped with the vehicle system of this embodiment as in the example of FIG. 11, the power assist amount and the regenerative power amount for the vehicle 30 can be increased. Although this contributes to the reduction of fuel consumption, the auxiliary drive motor 35b may not be mounted.

  FIG. 13 shows an example in which the wheel bearing device 1 according to any of the embodiments is applied to the driving wheel 10A as a front wheel and the driven wheel 10B as a rear wheel. The drive wheel 10A is driven by the main drive source 35 consisting of an internal combustion engine via the clutch 36 and the reduction gear 37. In the front wheel drive vehicle, the wheel bearing device 1 is installed to support and assist the drive wheels 10A and the driven wheels 10B. As described above, the wheel bearing device 1 can be applied not only to the driven wheel 10B but also to the driving wheel 10A.

Although the vehicle system shown in FIGS. 11 and 12 has a function of generating power, it may be a system not performing rotational drive by power feeding. In this case, the braking power can be generated by storing the regenerative power generated by the motor 3 in the medium voltage battery 49. The braking performance can also be improved by using it together with or using the mechanical brake operating means 57. When limited to the function of generating electric power as described above, the individual control means 39 can be configured as an AC / DC converter (not shown) rather than an inverter. The AC / DC converter device has a function of charging the medium voltage battery 49 with the regenerative power of the motor 3 by converting a three-phase AC voltage into a DC voltage, and the control method is easy as compared with the inverter. Can be
As mentioned above, although the form for implementing this invention was demonstrated based on embodiment, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

DESCRIPTION OF SYMBOLS 1 ... bearing apparatus for wheels, 2 ... bearing for wheels, 3 ... motor (power device), 4 ... outer ring (fixed ring), 4 a ... outer ring main body, 4 b ... intermediate member, 5 ... inner ring (rotating ring), 6 ... rolling Dynamic body, 7 Hub flange, 8 Frame frame parts, 12 Brake rotor, 17 Brake, 18 Stator, 18a Core, 18b Winding coil, 18ba Coil end, 19b Magnetic body
19c: Permanent magnet, 23: Case, 23b: Rotating case, 23a: Fixed case, 25: Sealing member, 63: Rotational sensor, 66: Communication oil passage, 68: Stator-rotor gap, 69, 70: Coil end accommodation Space 71: Bearing end adjacent space 73: Circulating oil passage 74: Impeller (recirculating force generating means) 75: Secondary cooling device 77: Pump (recirculating force generating means) 78: Pressure pump (recirculating force Generating means), 82 ... thread groove (circulation force generating means)

Claims (13)

A bearing for a wheel having a fixed wheel, and a rotating wheel rotatably supported by the fixed wheel via a rolling element to which a vehicle wheel is attached, a stator attached to the fixed wheel, and a rotor attached to the rotating wheel And a power unit having the
A clearance between a stator and a rotor formed between the stator and the rotor, a pair of coil end accommodation spaces formed in the power unit around coil ends on both sides of the stator, and the rotating wheel on the underframe part side A case is provided for sealing the space adjacent to the bearing end located in the axial direction of the
A bearing apparatus for a wheel, further comprising: a circulation force generation unit that circulates a cooling oil in a circulation oil passage provided in the case.   The bearing apparatus for a wheel according to claim 1, wherein a communication oil passage passing through the inside of the fixed wheel is provided, and the space adjacent to the bearing end, the communication oil passage, and one of the coil ends are accommodated in the case. A bearing device for a wheel, wherein the circulating oil passage is formed which sequentially circulates through a space, a space between the stator and the rotor, the other coil end accommodation space, and a space adjacent to the bearing end.   The wheel bearing device according to claim 1 or 2, wherein the circulating force generation means circulates the cooling oil by relative rotation between the rotating wheel and a fixed wheel of the wheel bearing.   The wheel bearing device according to any one of claims 1 to 3, wherein the wheel bearing is an inner ring rotating type in which the rotating wheel is an inner ring, and the power unit is an outer rotor type. A bearing apparatus for a wheel according to claim 1, wherein the case includes a fixed case fixed to the fixed wheel and a rotating case fixed to the rotary wheel and the rotor.   The wheel bearing device according to any one of claims 1 to 4, wherein the fixed wheel has a fixed wheel main body having a raceway surface for rolling the rolling elements, and the fixed wheel main body is externally fitted to the fixed wheel main body. And an intermediate member to which the stator is attached at an outer periphery thereof, wherein the communication oil passage is formed in the intermediate member.   The wheel bearing device according to any one of claims 1 to 5, wherein the circulating force generating means is an impeller located in the space adjacent to the bearing end and coaxially connected to the rotating wheel. Bearing assembly for wheels.   The wheel bearing device according to any one of claims 1 to 6, further comprising a secondary cooling device for cooling a cooling oil flowing in the circulating oil passage, in the middle of the circulating oil passage. .   The wheel bearing device according to any one of claims 1 to 7, wherein the wheel force bearing device includes a pump that enhances the circulation force of the cooling oil in the circulation oil passage as the circulation force generation unit.   The wheel bearing device according to any one of claims 1 to 8, wherein, as the circulating force generating means, a periphery that constitutes the gap between the stator and the rotor in one or both of the rotor and the stator. A bearing apparatus for a wheel having a thread groove on a surface to generate a pressure gradient by relative rotation of the rotor and the stator.   The wheel bearing apparatus according to any one of claims 1 to 9, wherein the wheel bearing is a bearing that supports a driven wheel mechanically disconnected from a main drive source of the vehicle. Bearing equipment.   The wheel bearing apparatus according to any one of claims 1 to 9, wherein the wheel bearing is a bearing that supports a drive wheel mechanically coupled to a main drive source of the vehicle. Bearing equipment.   A vehicle comprising the wheel bearing device according to any one of claims 1 to 11. A power unit comprising a motor generator installed on a wheel bearing, comprising:
A stator attached to a fixed wheel of the wheel bearing, and a rotor attached to a rotating wheel of the wheel bearing;
The power unit is an outer rotor type in which the stator is located on the outer periphery of the wheel bearing and the rotor is located radially outward of the stator.
The entire power unit is smaller in diameter than an outer peripheral portion of a brake rotor attached to the rotary wheel, which is a portion to which the brake caliper is pressed, and is provided on the outboard side of the rotary wheel in the power unit. The entire portion except the mounting portion to the hub flange is located in an axial range between the hub flange and a vehicle mounting surface on the inboard side of the wheel bearing,
A clearance between the stator and the rotor formed between the stator and the rotor, a pair of coil end accommodation spaces formed in the generator around the coil ends on both sides of the stator, and A case is provided for sealing the bearing end adjacent space located axially adjacent to each other,
Circulating force generating means for circulating cooling oil in a circulating oil passage provided in the case is provided.
Power plant.

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