WO2019078216A1

WO2019078216A1 - Vehicle power device and wheel bearing device with generator

Info

Publication number: WO2019078216A1
Application number: PCT/JP2018/038534
Authority: WO
Inventors: 浩希藪田; 健太郎西川; 光生川村; 康之藤田; 雄司矢田
Original assignee: Ntn株式会社
Priority date: 2017-10-17
Filing date: 2018-10-16
Publication date: 2019-04-25

Abstract

This vehicle power device (1) comprises: a wheel bearing (2) that has a fixed ring (4) and a rotating ring (5); and an electric motor (3) that has a stator (18) and a rotor (19). The stator (18) and the rotor (19) of the motor generator (3) are smaller in diameter than the outer periphery (12b) of a brake rotor (12), and the whole of the electric motor (3) except for an attachment portion to be attached to a hub flange (7) is located in an axial range (L1) between the hub flange (7) and the outboard side surface of an underbody frame component (8). An insulating layer (9) is interposed between the fixed ring (4) and the stator (18).

Description

POWER DEVICE FOR VEHICLE AND BEARING DEVICE WITH GENERATOR

Related application

This application claims the priority of Japanese Patent Application Nos. 201722007/2007 filed on Oct. 17, 2017 and Japanese Patent Application No. 2018/165590 filed on September 5, 2018, which are incorporated by reference in their entirety. Quoted as making money.

The present invention relates to a vehicular power unit including a bearing for a wheel and a generator, and a bearing unit for a wheel with a generator, wherein the potential difference between the inner and outer rings of the bearing caused by mounting the generator is eliminated in the bearing. The present invention relates to a technology capable of preventing electrolytic corrosion.

In a wheel bearing having a rotor and a stator, when a spark is generated between the rolling element and the bearing raceway surface due to the potential difference between the fixed ring and the hub flange, the bearing rolling element and the rolling surface are melted by the spark Corrugated electrolytic corrosion occurs. When electrolytic corrosion occurs, noise is emitted from the bearings, which also causes short bearing life.

In a wheel drive device which uses a motor as a drive source, a technique for preventing electrolytic corrosion of a rolling bearing portion has been proposed (Patent Document 1). In this technology, in a wheel drive device that uses an inner rotor type motor as a drive source, in order to electrically energize the rotor and the stator, a conical surface or spherical contact body electrically connected to the stator is pressed against the rotor This prevents electrolytic corrosion of the rolling bearing portion of the wheel bearing.

As shown in FIG. 15, in the wheel structure provided with the outer rotor type motor configured between the wheel bearing and the brake rotor, the applicant applies the current-carrying brush between the fixed wheel of the wheel bearing and the hub flange. The technology to which Br is attached is proposed (Japanese Patent Application No. 2017-113246). By energizing the potential difference generated between the inner and outer rings of the wheel bearing with the energizing brush Br, the potential difference between the rotor and the stator is eliminated, the energization between the hub flange and the fixed wheel through the rolling element 60 is prevented, Prevent food.

Patent No. 5402619

The configuration described in Patent Document 1 corresponds only to a vehicle drive device that uses an inner rotor type motor as a drive source. Further, the number of parts of the galvanic corrosion preventing unit for pressing the contact body to the rotor is large, the structure is complicated and the manufacturing cost is high. Therefore, in the configuration shown in FIG. 15, the current-carrying brush Br is provided between the fixed wheel of the wheel bearing and the hub flange, which corresponds to a vehicle drive device using an outer rotor type motor as a drive source. In this case, the potential difference is eliminated by supplying the potential difference generated in the inner and outer rings of the wheel bearing to the current-carrying brush Br, and the electrolytic corrosion due to the spark of the rolling element 60 is prevented. However, since the contact surface of the conical surface or the spherical surface or the current-carrying brush Br continues to slide during rotation of the wheel bearing, the current-carrying capacity is reduced due to wear, and periodical replacement is required.

An object of the present invention is to provide a vehicular power unit and a generator-equipped wheel bearing unit capable of preventing electrolytic corrosion of a bearing for a wheel and being maintenance-free with respect to the function of insulation.

According to a first aspect of the present invention, a vehicle power unit has a fixed wheel and a hub flange, and is rotatably supported by the fixed wheel via a rolling element, and the wheel and brake rotor of the vehicle are attached to the hub flange. A wheel bearing having a rotating wheel
A vehicle power unit comprising: a stator attached to the fixed wheel of the wheel bearing; and an electric motor having a rotor attached to the rotary wheel of the wheel bearing.
The stator and part or all of the rotor are smaller in diameter than the outer peripheral part of the brake rotor where the brake caliper is pressed, and the entire portion excluding the mounting portion to the hub flange of the electric motor is the above. In an axial range between the hub flange and the outboard side of the undercarriage part of the vehicle,
An insulating layer is interposed between the fixed ring and the stator.

According to this configuration, since the rotor of the motor is a direct drive type mounted on the rotating wheel of the wheel bearing, the number of parts of the entire vehicle power unit is small, the configuration is simple and space saving is realized, and the weight of the vehicle is increased. Can be suppressed.

Part or all of the stator and the rotor are smaller in diameter than the outer periphery of the brake rotor, and the whole of the motor except for the attachment to the hub flange is the hub flange and the outboard side of the underframe part. Located in the axial range between. For this reason, the space which installs an electric motor in a brake rotor is secured, and this electric motor can be stored compactly.

By the way, it is difficult to secure a space for installing the electric corrosion preventing unit for a vehicle power unit in which all the components fit in the brake rotor because the electric corrosion preventing unit of the conventional structure has a large number of parts. . This construction requires an insulation structure that is more compact than a typical in-wheel motor because it is a vehicle power unit that fits all the components in the brake rotor. According to this configuration, a small amount of space between the fixed wheel and the stator By interposing the insulating layer in the annular space by utilizing the annular space, the diameter of the entire vehicle power unit can be increased without increasing the diameter of the vehicle (in other words, the components of the vehicle power unit can be accommodated in the brake rotor) Can be cut off by the insulating layer.

Moreover, the following advantages are mentioned as a countermeasure against galvanic corrosion compared with the structure which used the electricity supply brush.
(1) It is easy to check when checking for electrical corrosion measures.
As the above reason, in a state where the power unit for a vehicle is assembled, it is not possible to check whether the inner and outer rings of the bearing are electrically connected by the current-carrying brush only by measuring the electrical resistance between the inner and outer rings. On the other hand, in the configuration of the present invention in which the insulating layer is interposed between the fixed ring and the stator, if the insulation is measured by measuring the electrical resistance between the stator and the fixed ring or between the stator and the rotating ring, electrolytic corrosion occurs. I can not get it.
(2) Since the insulating layer does not wear as in the case of a current-carrying brush, there is no need to replace it and the cost can be reduced. As the above-mentioned reason, since the insulating layer does not slide, deterioration due to the elapse of the operation time does not occur.

As described above, since the insulating layer is interposed between the fixed ring and the stator, the electrical corrosion of the wheel bearing can be prevented by interrupting the current flow to the rolling elements by the insulating layer. By preventing electrolytic corrosion of the wheel bearing, abnormalities of the rolling element and rolling surface of the wheel bearing can be prevented, life extension of the wheel bearing can be expected, and noise from the wheel bearing can be prevented beforehand. obtain. Since the insulating layer does not need to be replaced without being worn like a current-carrying brush or the like, maintenance is free with respect to the function of insulation. Therefore, the cost can be reduced as compared with the conventional example using a conductive brush or the like.

The electric motor may be 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. In this case, the area in which the rotor and the stator face can be increased more than in the inner rotor type. This makes it possible to maximize the output torque in a limited space.

The motor may be a motor generator capable of rotationally driving the wheel. When the vehicle power unit provided with the motor generator is mounted on a vehicle equipped with a conventional internal combustion engine or the like, the fuel efficiency can be reduced by the power assist by the motor generator. In the configuration in which the reduction gear mechanism of the conventional example is mounted, there is no need to install a motor generator around the wheel bearing, and a configuration in which no potential difference occurs in the inner and outer rings of the bearing can be obtained. When the stator and the rotor of the motor generator are formed between the bearing inner and outer rings, a potential difference is generated between the bearing inner and outer rings. Therefore, the present invention is limited to the configuration in which the direct drive type motor generator is mounted on the wheel bearing.

The driving voltage or regenerative voltage for rotational driving of the motor may be 60 V or less. In this case, a so-called medium-voltage battery can be mounted on the vehicle at a lower voltage than a high-voltage battery of 100 V or more used in a so-called strong hybrid vehicle etc. As a result, for example, even in a vehicle having only an internal combustion engine, a mild hybrid vehicle can be obtained without significant modification of the vehicle.

Between the fixed ring and the stator, there is provided an intermediate member for fixing the fixed ring to the frame frame part, and between the intermediate member and the fixed ring and between the intermediate member and the stator Either or both may be equipped with the said insulating layer. When the insulating layer is provided between the intermediate member and the stator, the insulating layer can be made of a soft material such as a resin material or a rubber material. This is because the force acting between the intermediate member and the stator is only the force generated by the generator and does not require so much strength. If an insulating layer is provided between the intermediate member and the fixed ring, the insulating layer needs a rigid insulating material between the intermediate member and the fixed ring. The force generated by the motion of the vehicle and the vehicle acts between the intermediate member and the fixed wheel.

An intermediate member may be provided between the fixed ring and the stator to fix the fixed ring to the undercarriage frame part, and the intermediate member may be made of an insulating material. In this case, the number of parts can be reduced and the structure can be simplified as compared to providing a member made of an insulating material in addition to the intermediate member.

In the first configuration, an insulating material may be provided between the rotor and the rotating wheel. In addition to the energization of the rolling elements by the potential difference between the inner and outer rings of the bearing described above, the generation of a small amount of eddy current between the rotor of the motor and the stator may cause the rolling elements to energize the rolling elements from the rotor. According to this configuration, in addition to the configuration in which the insulating layer is interposed between the fixed wheel and the stator, by providing the insulating material between the rotor and the rotating wheel, the rotor and the rotating wheel are insulated, and Electric corrosion can be prevented more reliably.

A power unit for a vehicle according to a second aspect of the present invention has a fixed wheel and a hub flange, and is rotatably supported by the fixed wheel via a rolling element, and the wheel and brake rotor of the vehicle are attached to the hub flange. A wheel bearing having a rotating wheel
A vehicle power unit comprising: a stator attached to the fixed wheel of the wheel bearing; and an electric motor having a rotor attached to the rotary wheel of the wheel bearing.
The stator and part or all of the rotor are smaller in diameter than the outer peripheral part of the brake rotor where the brake caliper is pressed, and the entire portion excluding the mounting portion to the hub flange of the electric motor is the above. In an axial range between the hub flange and the outboard side of the undercarriage part of the vehicle,
The rolling element is made of an insulating material.

According to this configuration, since the rolling elements are made of the insulating material, it is possible to prevent the electrolytic corrosion of the wheel bearing by interrupting the energization of the rolling elements. By preventing the electrolytic corrosion of the wheel bearing, abnormalities of the rolling element and the rolling surface of the wheel bearing can be prevented, and the life extension of the wheel bearing can be expected. Since the rolling element made of the insulating material does not need to be replaced without being worn like a current-carrying brush or the like, it becomes maintenance free with respect to the function of insulation. Therefore, the cost can be reduced as compared with the conventional example using a conductive brush or the like.

The generator-equipped wheel bearing device in the present invention has a fixed wheel and a hub flange, and is rotatably supported by the fixed wheel via a rolling element, and a wheel and a brake rotor of a vehicle are attached to the hub flange. A wheel bearing having a wheel;
A generator bearing bearing device comprising: a stator attached to the fixed wheel of the wheel bearing; and a generator having a rotor attached to the rotating wheel of the wheel bearing;
Part or all of the stator and the rotor are smaller in diameter than the outer peripheral part of the brake rotor where the brake caliper is pressed, and the whole excluding the mounting portion to the hub flange in the generator is In an axial range between the hub flange and the outboard side of an undercarriage part of the vehicle,
An insulating layer is interposed between the fixed ring and the stator.

According to this configuration, by interposing the insulating layer in the annular space utilizing a slight annular space between the fixed ring and the stator, the entire diameter of the generator-equipped wheel bearing apparatus is not increased ( In other words, it is possible to cut off the current flow to the rolling elements by the insulating layer without impeding that the components of the generator-equipped wheel bearing assembly are contained in the brake rotor. This can prevent electrolytic corrosion of the wheel bearing. In addition, the same effects as those of the power unit for a vehicle according to the first configuration are obtained.

An insulating material may be provided between the rotor and the rotating wheel. In addition to the energization of the rolling elements due to the potential difference between the inner and outer rings of the bearing described above, the generation of a small amount of eddy current between the rotor and the stator of the generator may cause the rolling elements to energize the rolling elements from the rotor. According to this configuration, in addition to the configuration in which the insulating layer is interposed between the fixed wheel and the stator, by providing the insulating material between the rotor and the rotating wheel, the rotor and the rotating wheel are insulated, and Electric corrosion can be prevented more reliably.

Any combination of the at least two configurations disclosed in the claims and / or the description and / or the drawings is included in the present invention. In particular, any combination of two or more of the claims is included in the present invention.

The invention will be more clearly understood from the following description of the preferred embodiments with reference to the accompanying drawings. However, the embodiments and the drawings are for the purpose of illustration and description only and are not to be taken as limiting the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in multiple drawings indicate the same or corresponding parts.
FIG. 1 is a cross-sectional view of a power unit for a vehicle (bearing device with a generator) according to an embodiment of the present invention. It is a side view of the power unit for the same vehicles. It is a front view of the power unit for the same vehicles. It is the IV-IV sectional view taken on the line of FIG. It is the perspective view which looked at the intermediate member of the power unit for the same vehicles from the knuckle surface. FIG. 6 is a cross-sectional view of a vehicular power unit according to another embodiment of the present invention. It is a cross-sectional view of a vehicular power unit according to still another embodiment of the present invention. It is a cross-sectional view of a vehicular power unit according to still another embodiment of the present invention. It is a cross-sectional view of a vehicular power unit according to still another embodiment of the present invention. It is XX sectional drawing of FIG. It is sectional drawing which shows roughly the fixing method of the insulating material in the power plant for the same vehicles. It is a cross-sectional view of a vehicular power unit according to still another embodiment of the present invention. FIG. 1 is a block diagram showing a conceptual configuration of a vehicle system of a vehicle provided with any of the vehicle power devices. It is a power supply system figure used as an example of the vehicles carrying the system for vehicles. It is sectional drawing of the power unit for vehicles of a prior art example.

A vehicular power unit according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. As shown in FIG. 1, the vehicle power unit 1 includes a wheel bearing 2 and a motor generator 3 which is a generator that doubles as an electric motor. In addition, the bearing apparatus for wheels with a generator which concerns on embodiment of this invention can be comprised by employ | adopting the generator which does not serve as an electric motor instead of the motor generator 3 in the vehicle motive power apparatus 1. FIG. That is, the generator-equipped wheel bearing apparatus includes the generator 3 that does not share the motor, and the wheel bearing 2. The generator-equipped wheel bearing device has the same configuration as the vehicle power unit 1 except for the motor generator 3 which also serves as an electric motor.

<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. Grease is enclosed in the bearing space between the outer ring 4 and the inner ring 5. The inner ring 5 has a hub ring 5a and a partial inner ring 5b fitted to the inboard outer peripheral surface of the hub ring 5a. The hub wheel 5 a has a hub flange 7 at a location protruding toward the outboard side in the axial direction with respect to the outer ring 4.

A wheel rim (not shown), a brake rotor 12 and a case bottom 11 (described later) are attached to the side surface on the outboard side of the hub flange 7 by a hub bolt 13 in an axially overlapping manner. A tire not shown is mounted on the outer periphery of the rim. In this specification, when the power unit for a vehicle 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 the inboard Call it the side.

<About the brake>
As shown in FIGS. 2 and 3, the brake is a friction brake provided with a disc-type brake rotor 12 and a brake caliper Kp. FIG. 1 is a cross-sectional view taken along line II of FIG. As shown in FIG. 1, the brake rotor 12 has a flat portion 12 a and an outer peripheral portion 12 b. The flat portion 12 a is an annular and flat member overlapping the hub flange 7 via the case bottom 11. The outer circumferential portion 12 b extends from the flat plate portion 12 a to the outer circumferential side of the outer ring 4. The outer peripheral portion 12b is a cylindrical portion 12ba cylindrically extending from the outer peripheral edge of the flat portion 12a to the inboard side, and a flat portion 12bb extending from the inboard end of the cylindrical portion 12ba to the outer diameter side And.

The brake caliper Kp has a friction pad that holds the flat plate portion 12bb of the brake rotor 12 therebetween. The brake caliper Kp is attached to a knuckle 8 which is an underbody frame part of a vehicle. The brake caliper Kp may be either hydraulic or mechanical, and may be electric motor.

<About the motor generator 3>
The motor generator 3 of this example is a motor generator (motor) for travel assistance which can generate electric power by rotation of the wheels and can rotationally drive the wheels by being supplied with electricity. Hereinafter, the motor generator 3 may be referred to as the motor 3. The motor generator 3 has a rotating case 15, a stator 18 and a rotor 19. The rotating case 15 is attached to the hub flange 7 and covers the rotor 19 and the stator 18. The motor generator 3 is an outer rotor type in which the rotor 19 is located radially outward of the stator 18. Further, the rotor 19 of the motor generator 3 is a direct drive type mounted on the inner ring 5 which is a rotating wheel of the wheel bearing 2.

In the motor generator 3, all of the stator 18 and the rotor 19 are smaller in diameter than the outer peripheral portion 12 b of the brake rotor 12. Furthermore, the whole of the motor generator 3 except for the attachment portion to the hub flange 7 is located in the axial range L1 between the hub flange 7 and the outboard side surface 8 a of the knuckle 8.

The motor generator 3 is an outer rotor type IPM (Interior Permanent Magnet) synchronous motor (or denoted as IPMSM (Interior Permanent Magnet Synchronous Motor)). Alternatively, the motor generator 3 may be an SPM synchronous motor. In addition, the motor generator 3 can adopt various types such as a switched reluctance motor (abbreviation: SR motor), an induction motor (induction motor: abbreviation: IM) and the like. In each motor type, each type of distributed winding and concentrated winding can be adopted as a winding type of the stator 18.

The rotating case 15 is composed of a bottomed cylindrical case body 16. The case main body 16 has a case bottom 11 and a case cylindrical portion 25. The case bottom 11 and the case cylindrical portion 25 are integrally or separately formed. The case bottom 11 is a flat and annular member sandwiched between the flat portion 12 a of the brake rotor 12 and the hub flange 7. A case cylindrical portion 25 extends cylindrically from the outer peripheral edge of the case bottom 11 toward the inboard side.

A small diameter portion, a medium diameter portion and a large diameter portion are provided on the inner peripheral surface of the case cylindrical portion 25 sequentially from the outboard side to the inboard side. As shown in FIG. 4, the rotor 19 includes a magnetic body 19 a provided by press-fitting or the like in the middle diameter portion of the case cylindrical portion 25 and a plurality of permanent magnets 19 b built in the magnetic body 19 a. As shown in FIG. 1, the outboard side end of the rotor 19 abuts on the stepped portion connecting the small diameter portion and the medium diameter portion of the case cylindrical portion 25, whereby the rotor 19 with respect to the rotation case 15 is obtained. Are positioned in the axial direction.

The stator 18 is attached to the outer peripheral surface of the outer ring 4 via the insulating layer 9 and a stator holding member 24 which is an intermediate member. As shown in FIGS. 1 and 4, the stator 18 has a core 18 a and coils 18 b wound around the teeth of the core 18 a. The coil 18 b is connected to the wiring 17 (FIG. 1).

As shown in FIG. 1, the stator holding member 24 holds the stator 18 in contact with the inner peripheral surface of the stator 18 and the end face on the outboard side. The stator 18 is, for example, fixed to the stator holding member 24 in the rotational direction and the radial direction by press-fitting or bolt fastening. Further, the stator holding member 24 is fixed to the outer peripheral surface of the outer ring 4 via the insulating layer 9 by press fitting or the like.

The stator holding member 24 and the knuckle 8 are fastened by a bolt 20. Between the inboard side end face of the stator holding member 24 and the outboard side face of the knuckle 8, the cover standing plate portion 22a of the unit cover 22 is interposed. As shown in FIG. 5, of the stator holding member 24 which is an intermediate member, on the end face on the inboard side (knuckle surface side), the wire connection of the coil 18b (FIG. 1) A plurality of (six in this example) communication holes 24c are provided in the circumferential direction to be passed from the inside to the inside diameter side. For example, a plurality of communication holes 24 c are formed by providing notches of equal circumferential distribution on the end surface on the inboard side of the stator holding member 24. The plurality of communication holes 24c need not be circumferentially equidistant, and may be communication holes generally passing through the wiring 17 (FIG. 1) formed of three lines of U-phase, V-phase and W-phase. As shown in FIG. 1, the knuckle 8 is formed with a through hole 8b for allowing insertion of the outer peripheral surface of the cylindrical portion 22b in the unit cover 22. Through holes 8b of the unit cover 22 are inserted through a plurality of bolts 20 (see FIG. 1). Not shown) is formed.

As shown in FIGS. 1 and 5, a plurality of female threads 24d extending in the axial direction are circumferentially equidistantly formed on the stator holding member 24. As shown in FIG. Through holes (not shown) in the same phase as the respective female screws 24 d are formed in the cover upright plate portion 22 a. The bolts 20 are inserted from the inboard side of the knuckles 8 into the insertion holes of the knuckles 8 and screwed to the female screws 24 d of the stator holding member 24 through the through holes of the cover upright plate portion 22 a.

<About insulating layer 9>
As shown in FIG. 1, an annular recess 24 a that is recessed outward in the radial direction is formed on the inner peripheral surface of the stator holding member 24. An insulating layer 9 made of an insulating material having a cylindrical shape and desired rigidity is inserted in the annular recess 24a. Examples of the material of the insulating layer 9 include an insulating soft material such as a resin material or a rubber material, or an insulating material such as a ceramic. An insulating layer 9 made of a rigid insulating material is preferable because a force generated by the vehicle weight and the motion of the vehicle acts between the stator holding member 24 which is the intermediate member and the outer ring 4.

The axial length, that is, the width dimension of the insulating layer 9 is substantially the same as the width dimension of the outer peripheral surface of the outer ring 4 and is formed so as to cover all the outer peripheral surface of the outer ring 4. According to the drive voltage of the generator 3, it sets suitably. By interrupting the current flow to the rolling elements 6 by such an insulating layer 9, the electrolytic corrosion of the wheel bearing 2 can be prevented. For example, the insulating layer 9 may be formed by applying or spraying an insulating material on either or both of the inner circumferential surface of the stator holding member 24 and the outer circumferential surface of the outer ring 4.

<About seal structure>
A seal member 23 is disposed between the rotation case 15 and the outboard side surface of the knuckle 8 to prevent the entry of water and foreign matter into the motor generator 3 and the wheel bearing 2. The seal member 23 has an annular seal plate and an elastic seal member facing each other. An annular rotor end ring member 26 is fixed to the large diameter portion and the end face of the case cylindrical portion 25 of the rotation case 15 by bolts. An axial gap is formed between the rotor end ring member 26 and the outboard side surface 8 a of the knuckle 8.

An annular groove is formed on the outer peripheral surface of the rotor end ring member 26, and an O-ring is provided in the annular groove. The O-ring seals the contact surface between the end inner peripheral surface of the rotating case 15 and the rotor end ring member 26. The rotor end ring member 26 also serves as a positioning member in the axial direction of the permanent magnet 19 b (FIG. 4) incorporated in the magnetic body 19 a (FIG. 4).

<About the rotation detector etc.>
The vehicle power unit 1 is provided with a rotation detector 27. The rotation detector 27 is located inside the hollow of the stator 18. The rotation detector 27 detects the rotation angle or rotation speed of the inner ring 5 with respect to the outer ring 4 in order to control the rotation of the motor generator 3 for driving assistance. The rotation detector 27 has a detected portion 27a attached to the detected portion holding member 28 and the like, and a sensor portion 27b attached to the inner peripheral surface of the stator holding member 24 to detect the detected portion 27a. For example, a resolver is applied as the rotation detector 27. The rotation detector 27 is not limited to the resolver, and may be, for example, an encoder, a pulser ring or a Hall sensor regardless of the type.

<Wires etc>
A connector cover 66 covering the inboard end is detachably attached to the inboard end of the cylindrical portion 22b of the unit cover 22 by a plurality of bolts. The wiring 17 of the motor generator 3 is supported by the connector cover 66 via a so-called panel mount type power line connector 67. The connector cover 66 also supports a panel mount type sensor connector 64.

<Function effect>
According to the power unit 1 for a vehicle described above, since the rotor 19 of the motor generator 3 is a direct drive type attached to the inner ring 5 which is a rotating wheel of the wheel bearing 2, a configuration including a speed reduction mechanism etc. Also, the number of parts of the entire power plant for a vehicle is small, the configuration is simple, space is saved, and the increase in the weight of the vehicle can be suppressed. In the configuration in which the reduction gear mechanism of the conventional example is mounted, there is no need to install an electric motor around the wheel bearing, and a configuration in which no potential difference occurs in the inner and outer rings of the bearing can be obtained. When the stator and the rotor of the motor are formed between the bearing inner and outer rings, a potential difference is generated between the bearing inner and outer rings. Therefore, the embodiment of the present invention is limited to the configuration in which the direct drive type motor generator is mounted on the wheel bearing.

The whole of the stator 18 and the rotor 19 is smaller in diameter than the outer peripheral portion 12b of the brake rotor 12, and the whole of the motor generator 3 excluding the mounting portion to the hub flange 7 is the hub flange 7 and the outboard side face of the knuckle 8. It is located in the axial range L1 between 8a and 8a. For this reason, the space which installs motor generator 3 in brake rotor 12 is secured, and this motor generator 3 can be stored compactly.

By the way, it is difficult to secure a space for installing the electric corrosion preventing unit for a vehicle power unit in which all the components fit in the brake rotor because the electric corrosion preventing unit of the conventional structure has a large number of parts. . The vehicle power unit, in which all the components fit within the brake rotor, requires a more compact insulating structure than a conventional in-wheel motor. According to this configuration, the space between the outer ring 4 and the stator 18 By interposing the insulating layer 9 in the annular space using a slight annular space, the diameter of the entire vehicle power unit 1 is not increased (in other words, the vehicle power unit 1 is installed in the brake rotor 12). The insulation layer 9 can cut off the current flow to the rolling elements 6 without inhibiting the components from being contained.

Moreover, the following advantages are mentioned as a countermeasure against galvanic corrosion compared with the structure which used the electricity supply brush.
(1) It is easy to check when checking for electrical corrosion measures.
As the above reason, in a state where the power unit for a vehicle is assembled, it is not possible to check whether the inner and outer rings of the bearing are electrically connected by the current-carrying brush only by measuring the electrical resistance between the inner and outer rings. On the other hand, in the configuration of the present embodiment in which the insulating layer 9 is interposed between the outer ring 4 as the fixed ring and the stator 18, the insulation is obtained by measuring the electrical resistance between the stator 18 and the outer ring 4 or between the stator 18 and the inner ring 5. If done, electrolytic corrosion can not occur.
(2) Since the insulating layer 9 does not wear like a current-carrying brush, there is no need to replace it, and the cost can be reduced. As the above-mentioned reason, since the insulating layer 9 does not slide, deterioration due to the operation time does not occur.

As described above, since the insulating layer 9 is interposed between the outer ring 4 which is the fixed ring and the stator 18, the electric corrosion of the wheel bearing 2 is prevented by interrupting the current flow to the rolling elements 6 by the insulating layer 9. You can prevent. By preventing the electrolytic corrosion of the wheel bearing 2, abnormalities of the rolling element 6 and the rolling surface of the wheel bearing 2 can be prevented, and life extension of the wheel bearing 2 can be expected, and abnormal noise from the wheel bearing 2 Can be prevented in advance. Since the insulating layer 9 does not need to be replaced without being worn like a current-carrying brush or the like, maintenance is free with respect to the function of insulation. Therefore, the cost can be reduced as compared with the conventional example using a conductive brush or the like.

Since the motor generator 3 is an outer rotor type in which the rotor 19 is located outward in the radial direction of the stator 18, the area in which the rotor 19 and the stator 18 face each other can be increased compared to the inner rotor type. This makes it possible to maximize the output torque in a limited space.

<Other Embodiments>
In the following description, the portions corresponding to the items described in advance in each embodiment are denoted by the same reference numerals, and the redundant description will be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding embodiment unless otherwise stated. The same function and effect are exhibited from the same configuration. Not only the combination of the portions specifically described in the embodiments but also the embodiments may be partially combined if any problem does not occur in the combination.

As shown in FIG. 6, the vehicle power unit 1 may include an insulating layer 9A between the stator holding member 24 and the stator 18. The inner peripheral surface of the cylindrical insulating layer 9A is fixed to the outer peripheral surface of the stator holding member 24. A flange portion 24 b which protrudes a predetermined small distance outward in the radial direction is formed on the outer peripheral surface of the stator holding member 24 on the outboard side. The outboard side end face of the insulating layer 9A is in contact with the flange portion 24b and positioned in the axial direction.

The width dimension of the insulating layer 9A is substantially the same as the width dimension of the stator 18, and is formed so as to cover the outer peripheral surface of the stator holding member 24 with the insulating layer 9A. As a material of the insulating layer 9A, for example, a soft material having insulation such as a resin material or a rubber material is applied. The force acting between the stator holding member 24 and the stator 18 is only the force generated by the motor generator 3 and does not require so much strength. According to this configuration, the cost can be reduced more than that using the above-described insulating material such as ceramics. In addition, the same operation and effect as those of the above-described embodiment can be obtained. As a material of insulating layer 9A between stator holding member 24 and stator 18, it is also possible to use insulating materials, such as ceramics.

As shown in FIG. 7, the stator holding member 24 which is an intermediate member may be made of an insulating material. In this case, the number of parts can be reduced and the structuring can be simplified as compared to providing a member made of an insulating material in addition to the stator holding member 24. This can reduce the cost. In addition, the stator holding member 24 which is an intermediate member and the outer ring 4 may be an integral structure made of the same material instead of separate members. In this case, the inner peripheral surface of the stator 18 is fitted to the outer peripheral surface of the outer ring 4. According to this configuration, the rigidity of the intermediate member and the wheel bearing 2 can be increased, and the number of parts can be reduced.

As shown in FIG. 8, the rolling elements 6 may be made of an insulating material. Ceramics etc. can be applied as this insulating material. In this case, since the rolling element 6 is made of an insulating material, the electric corrosion of the wheel bearing 2 can be prevented by interrupting the current flow to the rolling element 6.

In the motor generator 3 of this example, although all of the stator 18 and the rotor 19 have a diameter smaller than that of the outer peripheral portion 12b of the brake rotor 12, the present invention is not limited to this example. For example, a part of the stator 18 and the rotor 19 may be smaller in diameter than the outer peripheral portion 12 b of the brake rotor 12. Although not shown, the motor generator may be an inner rotor type in which the rotor is located radially inward of the stator.

In addition to the configuration in which the insulating layer 9 is interposed between the outer ring 4 and the stator 18 as shown in FIGS. 9 to 11 (see FIG. 1), insulation is provided between the rotor 19 and the inner ring (rotating ring) 5 The material 31 may be interposed. As shown in FIGS. 9 and 10, a ring-shaped insulating material 31 is attached between the base end of the case cylindrical portion 25 on the outboard side of the rotation case 15 and the case bottom 11. The insulating material 31 is coaxial with the inner ring 5. In the rotation case 15 of this example, the case bottom 11 and the case cylindrical portion 25 are separately formed, and fixed by interposing the insulating material 31 by a bolt described later.

As shown in FIG. 11, a plurality of internal threads are formed at predetermined intervals in the circumferential direction at the base end of the case cylindrical portion 25 on the outboard side, and the insulating material 31 and the case bottom 11 In the female screw, bolt holes and countersunk holes of the same phase are formed. Bolts 29 are respectively inserted into the bolt holes from the outboard side of the rotation case 15 and fastened to the respective female screws. As a material of the insulating material 31 and the bolt 29, a rigid insulating member such as a resin material or a ceramic is preferable.

In addition to the energization of the rolling elements 6 due to the potential difference between the inner and outer rings of the bearing described above, a slight amount of eddy current is generated between the rotor 19 and the stator 18 of the motor generator 3. There is a risk of energizing. According to this configuration, in addition to the configuration in which the insulating layer 9 is interposed between the outer ring 4 and the stator 18, the insulating material 31 is provided between the rotor 19 and the inner ring 5, whereby insulation is provided between the rotor 19 and the inner ring 5. Thus, the electrolytic corrosion of the rolling element 6 can be prevented more reliably.

As a modified example of this configuration, although not shown, an insulating material may be applied or sprayed over the entire rotation case 15, or the material of the rotation case 15 may be resin or ceramics. According to this modification, the same effect as that of the above-described configuration can be obtained. In this case, those in which the material of the insulating material and the rotation case 15 is made of resin or ceramic correspond to the "insulating material" in the present specification. The configuration shown in FIG. 9 and a modified example in which an insulating material is applied or sprayed on the entire rotating case 15 may be provided.

As shown in FIG. 12, in addition to the configuration having the insulating layer 9A between the stator holding member 24 and the stator 18 (see FIG. 6), the insulating material 31 may be provided between the rotor 19 and the inner ring 5 as well. Good. Also in the rotation case 15 of this example, the case bottom 11 and the case cylindrical portion 25 are separately formed, and are fixed by interposing the insulating material 31 by the bolt. According to this configuration, by providing the insulating material 31 between the rotor 19 and the inner ring 5, the rotor 19 and the inner ring 5 are insulated, and the electrolytic corrosion of the rolling elements 6 can be more reliably prevented.

<About the system for vehicles>
FIG. 13 is a block diagram showing a conceptual configuration of a system for a vehicle using the power unit 1 for a vehicle according to any one of the embodiments. In the vehicle system, the vehicle power plant 1, in a vehicle having a driven wheel 10 _B is a main drive source mechanically unconnected, is mounted against the driven wheel 10 _B. Wheel bearing 2 in the vehicle power unit 1 (FIG. 1, 6-8, 9, 12) 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. It is a hybrid car (hereinafter may be 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 the transmission 37, the motor generator 35b of the driving wheel is connected to the transmission 37.

System for a vehicle includes an electric motor 3 is a power generator for the drive assistance for rotating driving of the driven wheels 10 _B, the individual control means 39 for controlling the electric motor 3, the individual control unit provided in the upper ECU40 And an individual motor generator command means 45 for outputting a command for performing control of drive and regeneration at 39. The motor 3 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 acts as a motor by supplying electric power, and also acts as a generator that converts kinetic energy of the vehicle 30 into electric power. As the motor 3 has the rotor 19 (FIG. 1) attached to the inner ring 5 (FIG. 1), the current is applied to the motor 3 and torque is generated in the traveling direction of the vehicle. Regenerative power is obtained by being driven and generating torque in the reverse direction. The driving voltage or regenerative voltage for rotational driving of the motor 3 is 60 V or less.

<About Control System of Vehicle 30>
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 a motor generator 35b of the internal combustion engine 35a and the drive wheel as the main drive source 35, and because with the two

electric motors

3, 3 for driving two driven wheels ₁₀ B, 10 _B, respectively, wherein The host ECU 40 is provided with a torque command distribution unit 44 that distributes the torque command to the

drive sources

35 a, 35 b, 3, 3 according to the rule defined.

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 and 3 are transmitted to the individual control means 39 and 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) and the like by a semiconductor switching element and the like.

The control unit 42 controls the motor 3 to follow the torque command generated by the individual motor generator command unit 45, for example, so that the generated torque matches. That is, the control unit 42 calculates the current to be applied to the motor 3 from the command torque, the rotation speed (which can be easily calculated in the case of the rotation angle sensor) detected by the rotation detector 27 (FIG. 1), and the test result. . Furthermore, the voltage applied to the motor 3 is calculated from the calculated current, the rotation angle, and the value of the current sensor (not shown). The calculated voltage is applied to the motor 3 to generate a torque that matches the command torque. Although the individual control means 39 is separately provided for the two

motors

3 and 3, it may be housed in one case and the control unit 42 may be shared by both individual control means 39, 39. .

FIG. 14 is a power supply system diagram as an example of a vehicle equipped with the system for a vehicle shown in FIG. In the example of the figure, a low voltage battery 50 and a medium power battery 49 are provided as batteries, and both the

batteries

49 and 50 are connected via a DC / DC converter 51. Although there are two electric motors 3, one is representatively shown. The motor generator 35b on the drive wheel side of FIG. 13 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 higher voltage than the low voltage battery 50 and is 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, an electric pump, an electric power steering, a supercharger, an air compressor, or the like which is the motor generator 35b on the drive wheel side. 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.

Since contrast to the vehicle system of this embodiment is mounted with respect to the driven wheels 10 _B, and the main drive source is disconnected such as an internal combustion engine 35a and the electric motor (not shown), the power regeneration In this case, the kinetic energy of the car body can be used directly. In addition, when CMG, GMG, a belt drive type starter motor, etc. are mounted, they need to be incorporated in consideration from the design stage of the vehicle 30, and it is difficult to retrofit.

In contrast, the motor 3 of the system for this vehicle to fit in the driven wheel 10 in _B, even complete vehicles can be mounted in part exchange the same steps, even for finished vehicles of the internal combustion engine 35a only A 48V system can be configured. In an existing vehicle equipped with only an internal combustion engine 35a, the vehicle power unit 1 according to any one of the embodiments, and a battery for a motor generator, the drive voltage or regenerative voltage for rotational drive of the motor is 60 V or less By mounting the medium voltage battery 49, it is possible to make a mild hybrid vehicle without significant modification of the vehicle. Another auxiliary drive motor generator 35b may be mounted on the vehicle equipped with the vehicle system of this embodiment as shown in FIG. At that time, the power assist amount and the regenerative electric energy for the vehicle 30 can be increased, which further contributes to the fuel consumption reduction.

Although not shown, the power unit for a vehicle according to any of the embodiments may be applied to the drive wheel. It is also possible to apply the vehicle power unit to the drive wheel and the driven wheel, respectively.

The vehicle system shown in FIG. 13 has a function of generating electric power, but may be a system which does not perform rotational drive by power feeding. On this vehicle system, a generator-equipped wheel bearing apparatus including a generator 3 that does not share an electric motor and a wheel bearing 2 is mounted. The bearing assembly for a wheel with a generator has the same configuration as that of the power unit for a vehicle according to any of the embodiments except for a motor generator which also serves as a motor. In this case, the braking power can be generated by storing the regenerative power generated by the generator 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 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 regenerative power of the generator 3 to the medium voltage battery 49 by converting a three-phase AC voltage into a DC voltage, and the control method is easy compared to an inverter, Miniaturization is possible.

In addition, in the power unit 1 for a vehicle according to the present application, the wheel bearing 2 includes a hub ring to which one partial inner ring is fitted as a rotary ring, and the outer ring which is a fixed ring and the hub ring and the partial inner ring Although it is set as the 3rd generation structure comprised by union, it does not limit to this.
A structure in which a hub having a hub flange and a member having a raceway surface of a rolling element are combined is a rotating wheel as referred to in the present specification. The wheel bearing 2 may be, for example, a first generation structure including an outer ring mainly serving as a fixed ring and an inner ring fitted to the outer peripheral surface of a hub having a hub flange, and the outer ring serving as a fixed ring The inner ring rotation type second generation structure may be provided with an inner ring fitted to an outer peripheral surface of a hub having a hub flange. In these examples, the combination of the hub and the inner ring corresponds to the "rotating wheel" in the present specification. The wheel bearing 2 may be of an outer ring rotation type second generation structure including an outer ring which is a rotating ring having a hub flange and an inner ring which is a fixed ring.

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.

1 Vehicle power unit 2 Wheel bearing 3 Motor generator (motor, generator)
4 ... Outer ring (fixed ring)
5 ... Inner ring (turning wheel)
7 ... Hub flange 8 ... knuckle (frame of underbody frame)
9, 9 A Insulating layer 12 Brake rotor 18 Stator 19 Rotor 24 Stator holding member (intermediate member)
31 ... Insulation material Kp ... Brake caliper

Claims

A wheel bearing having a fixed wheel, and a wheel flange having a hub flange and rotatably supported by the fixed wheel via rolling elements and having the wheel and brake rotor of the vehicle attached to the hub flange;
An electric motor having a stator attached to the fixed wheel of the wheel bearing, and a rotor attached to the rotating wheel of the wheel bearing;
A power unit for a vehicle comprising
The stator and part or all of the rotor are smaller in diameter than the outer peripheral part of the brake rotor where the brake caliper is pressed, and the entire portion excluding the mounting portion to the hub flange of the electric motor is the above. In an axial range between the hub flange and the outboard side of the undercarriage part of the vehicle,
A power plant for a vehicle, wherein an insulating layer is interposed between the fixed wheel and the stator.
The vehicular power apparatus according to claim 1, wherein the electric motor 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. apparatus.
The power unit for vehicles according to claim 1 or 2, wherein the electric motor is a motor generator capable of rotationally driving the wheels.
The power unit for vehicles according to claim 3, wherein a drive voltage or a regenerative voltage for rotational drive of the electric motor is 60 V or less.
The power unit for a vehicle according to any one of claims 1 to 4, further comprising an intermediate member for fixing the fixed wheel to the underbody frame part, between the fixed wheel and the stator. A power plant for a vehicle comprising the insulating layer at any one or both of an intermediate member and the fixed wheel, and between the intermediate member and the stator.
The power unit for a vehicle according to any one of claims 1 to 4, further comprising an intermediate member for fixing the fixed wheel to the underbody frame part, between the fixed wheel and the stator. A vehicle power unit wherein the intermediate member is made of an insulating material.
The power unit for vehicles according to any one of claims 1 to 6, wherein an insulating material is provided between the rotor and the rotating wheel.
A wheel bearing having a fixed wheel, and a wheel flange having a hub flange and rotatably supported by the fixed wheel via rolling elements and having the wheel and brake rotor of the vehicle attached to the hub flange;
An electric motor having a stator attached to the fixed wheel of the wheel bearing, and a rotor attached to the rotating wheel of the wheel bearing;
In a vehicle power unit provided with
The stator and part or all of the rotor are smaller in diameter than the outer peripheral part of the brake rotor where the brake caliper is pressed, and the entire portion excluding the mounting portion to the hub flange of the electric motor is the above. In an axial range between the hub flange and the outboard side of the undercarriage part of the vehicle,
A power device for a vehicle, wherein the rolling element is made of an insulating material.
A wheel bearing having a fixed wheel, and a wheel flange having a hub flange and rotatably supported by the fixed wheel via rolling elements and having the wheel and brake rotor of the vehicle attached to the hub flange;
A generator having a stator attached to the fixed wheel of the wheel bearing, and a rotor attached to the rotating wheel of the wheel bearing;
A generator-equipped wheel bearing apparatus comprising:
Part or all of the stator and the rotor are smaller in diameter than the outer peripheral part of the brake rotor where the brake caliper is pressed, and the whole excluding the mounting portion to the hub flange in the generator is In an axial range between the hub flange and the outboard side of an undercarriage part of the vehicle,
A bearing device for a wheel with a generator, wherein an insulating layer is interposed between the fixed wheel and the stator.
The bearing device for a wheel with a generator according to claim 9, wherein the insulating material is provided between the rotor and the rotating wheel.