JP4730078B2 - In-wheel motor - Google Patents

Description

  The present invention relates to an in-wheel motor that is arranged inside a wheel of a vehicle and rotationally drives a drive wheel.

  2. Description of the Related Art Conventionally, an in-wheel motor that is disposed inside a wheel of a vehicle and directly drives a driving wheel is widely known. Such an in-wheel motor has various advantages such as space saving on the vehicle body side, omission of a transmission and a differential gear, and omission of a drive shaft. Therefore, the in-wheel motor has a relatively small size such as a forklift and a golf cart. Widely implemented mainly in vehicles.

There are various types of in-wheel motors of this type. For example, in Patent Document 1 below, a stator and a rotor are arranged adjacent to each other in the rotation axis direction, and a brake disk is provided on the rotor. An integrally formed in-wheel motor is disclosed.
Specifically, the rotating member (20) is connected to the rotor (21), and the rotational driving force of the rotor (21) is transmitted to the rotating member (20). The rotating member (20) has a shaft portion (3) formed on the hub bearing (1) side and a large-diameter portion formed on the opposite side to the shaft portion (3). The shaft portion (3) is connected to the hub bearing (1) via a planetary gear mechanism (2) that functions as a speed reducer. The large diameter portion is configured to function as a brake disc of the vehicle.

With this configuration, the in-wheel motor is reduced in weight and size.
Japanese Patent Laying-Open No. 2005-212656

However, in the conventional technology, for example, it is not possible to divert a general automobile part running with an engine mounted thereon, and it is not possible to share the part. For this reason, parts such as hub bearings and brake discs have to be newly designed and manufactured exclusively for vehicles that run on in-wheel motors, resulting in increased costs.
For example, in the technology disclosed in Patent Document 1, the hub bearing 1 (particularly, the hub wheels 5, 51, 58, 74) and the planetary gear mechanism (planetary speed reducers 2, 53, 60, 64, 68, 71) are designed exclusively. It needs to be manufactured.

  In the technique of Patent Document 1, since the stator and the rotor of the in-wheel motor are provided adjacent to each other in the rotation axis direction, a large capacity (space) is required in the axle direction. For this reason, there is a possibility that the brake disc cannot be stored inside the wheel. In this case, it is sufficient to increase the wheel offset, but there is a possibility that the wheel may be designed exclusively. Furthermore, since the brake disc is located on the inner side of the vehicle than a general automobile, the mounting position of the brake caliper will be significantly changed, and it is necessary to newly install a stay or bracket for mounting the caliper. Arise.

On the other hand, the present applicant created and applied for an in-wheel motor as shown in FIG. That is, as shown in FIG. 4, in this in-wheel motor, the stator bracket 108 is fixed to a non-rotating portion (outer race) 107 of a hub unit (hub bearing) 104 that rotatably supports the wheel.
In addition, a stator 117 that is located inside the wheel 114 and is formed coaxially with the rotation axis L1 of the hub unit 104 is fixed to the stator bracket 108. An outer rotor bracket 113 is attached to the rotating portion (inner hub) 105 of the hub unit 104, and a cylindrical outer rotor 118 that covers the outer periphery of the stator 117 is attached to the outer rotor bracket 113.

Further, the same brake disc 112 as that used in a general automobile is disposed between the stator bracket 108 and the outer rotor bracket 113, and the brake disc 112 is fixed to the inner hub 105.
That is, the brake disk 112, the outer rotor bracket 113, and the wheel 114 are attached to the hub unit 104 in the order described above. The stator bracket 108 is fastened together using an existing fastening point between the knuckle and the hub unit 104 (not shown).

Therefore, it is not necessary to provide a dedicated attachment point for fixing the stator bracket 107 on the suspension side. In addition, by disposing the outer rotor bracket 113 between the brake disk 112 and the wheel 114, it is not necessary to add new parts to fix the outer rotor bracket 113.
With such a configuration, for example, a general suspension structure component that does not include an in-wheel motor can be diverted, and the component can be shared between an in-wheel motor vehicle and a normal engine-driven vehicle. Cost reduction can be achieved.

  However, in such a configuration, it is necessary to dispose the brake disc 112 and the brake caliper (not shown) in the outer rotor 113. For this reason, when the size of the brake disk 112 is not changed, the stator 117 and the outer rotor 118 are increased in diameter, and as a result, the motor is increased in size. As a result, the size of the wheel 114 increases, and a large size such as 19 inches or 20 inches is required. For this reason, the subject that a wheel of a general size cannot be used arises, and there is a subject that unsprung weight increases. Currently, large-diameter wheels with a size of 19 inches or 20 inches are also distributed in the market, but the distribution amount is extremely small as a whole, and it cannot be said that they are general.

  The present invention was devised in view of such a problem, and an object thereof is to provide an in-wheel motor that can reduce the size of a motor while allowing a general automobile suspension part to be used. And

Therefore, the in-wheel motor of the present invention includes a stator fixed to a non-rotating portion of a hub unit that rotatably supports a wheel with respect to a vehicle body, and an outer peripheral side of the stator fixed to the rotating portion of the hub unit. An outer rotor disposed on the outer rotor, and a brake disk fixed to the outer rotor. The outer rotor extends in a radially outward direction from the wall, the tubular wall extending to cover the stator. A brake disc mounting portion formed in a flange shape, and the brake disc is fixed to the outer peripheral side of the outer rotor by superimposing the brake disc mounting portion on the inner peripheral edge portion of the brake disc. (Claim 1).
Further, it is preferable that the outer rotor and the brake disc are integrated by being fastened by a bolt (Claim 2).

The wheel is preferably fastened to the hub unit by a hub bolt protruding from the rotating portion, and the outer rotor is preferably fixed to the rotating portion of the hub unit by a bolt different from the hub bolt. (Claim 3).
Further, the hub unit has a flange portion facing the mounting surface of the wheel, the outer rotor is polymerized in the flange portion of the hub unit having a mounting base for mounting the outer rotor to the hub unit, It is preferable that the wall portion extends from the mounting base so as to cover the stator and has a rotor main body therein.

  Furthermore, it is preferable that the stator, the outer rotor, and the brake disc are all located inside the wheel.

  According to the in-wheel motor of the present invention, by integrating the outer rotor and the brake disc in the outer-rotor type in-wheel motor, it is possible to divert general automobile suspension parts and reduce costs. In addition, the motor can be miniaturized and the diameter of the wheel can be avoided. As a result, a wheel having a general size (or a general-purpose wheel) can be used, and the cost and unsprung load can be reduced.

  Further, by fastening the outer rotor and the brake disc with bolts, even if the brake disc is worn, only the brake disc can be easily replaced. Further, by fixing the outer rotor to the hub unit with a bolt different from the hub bolt, it is possible to avoid a situation in which the outer rotor and the brake disc are accidentally dropped from the hub unit when the wheel is removed.

Hereinafter, an in-wheel motor according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing the configuration, FIG. 2 is an exploded perspective view showing the configuration, and FIG. It is a perspective view shown.
This embodiment demonstrates the case where an in-wheel motor is applied to the front wheel of a motor vehicle. Note that the in-wheel motor and the motor mounting portion on the vehicle body side are configured similarly to the front wheel side on the rear wheel side.

As shown in FIG. 1, a knuckle 3 is swingably connected to a lower arm 2 of a vehicle front wheel suspension via a pillow ball joint (spherical joint) 2a. The knuckle 3 is fixed to the lower end of the strut 1 via a strut bracket 1a.
A knuckle hole 3a is formed in the knuckle 3, and a hub bearing (or hub unit) 4 is inserted into the knuckle hole 3a. The hub bearing 4 mainly includes an inner hub 5 (rotating portion), a bearing 6, and an outer race or outer hub (non-rotating portion) 7. The outer hub 7 rotates on the outer peripheral side of the inner hub 5 via the bearing 6. Supported as possible.

  The outer periphery of the outer hub 7 is fitted into the knuckle hole 3 a of the knuckle 3. A flange portion 7a is integrally formed on the outer periphery of the outer hub 7, and a bolt hole for attaching a knuckle (not shown) is formed in a part of the flange portion 7a. A hub mounting portion 3b (see FIG. 2) in which a bolt hole is also formed is formed at a position corresponding to the bolt hole of the knuckle 3.

On the other hand, the in-wheel motor is mainly composed of a stator (stator) 8 and a rotor (outer rotor) 18 disposed on the outer peripheral side of the stator 8, of which the stator 8 includes the outer hub 7 and the knuckle 3. It is held between and fixed.
That is, the stator 8 is formed with a hole through which the outer hub 7 can be inserted, and the edge of the hole is overlapped with the flange 7a of the outer hub 7 as shown in FIG. Further, the stator 8 is also formed with bolt holes (not shown) at positions corresponding to the bolt holes formed in the flange 7a. The bolts 9 (see FIG. 2) are inserted into the bolt holes and the knuckle 3 is inserted. The knuckle 3, the stator 8, and the outer hub 7 are fixed by fastening the stator 8 and the outer hub 7 in this order.

Further, the inner hub 5 is formed with a flange portion (hub portion) 5 b at a position facing the mounting surface of the wheel 14. More specifically, the flange portion 5 b is a flange-like portion whose diameter is increased on the outer peripheral side at the outer side of the vehicle body than the outer end portion of the outer hub 7, and is integrally formed with the inner hub 5.
A plurality of stud bolts (wheel bolts) 11 that are parallel to the rotation axis L1 are arranged in this flange portion 5b in parallel with the rotation axis L1 of the bearing 6 as a center. 11 is fixed to the flange portion 5b with the tip facing outward of the vehicle.

On the other hand, the outer rotor 18 of the in-wheel motor mainly includes a mounting base 18b parallel to the flange 5b and a plurality of magnets (not shown) extending from the mounting base 18b so as to cover the stator 8. It is composed of a fixed cylindrical wall portion 18c and a brake disc mounting portion 18d formed to extend radially outward from the wall portion 18c.
A plurality of first bolt holes (not shown) are formed in the mounting base portion 18b of the outer rotor 18 at positions corresponding to the stud bolts 11, and the mounting surface of the wheel 14 is mounted after the outer rotor 18 is mounted on the flange portion 5b. Is superposed on the mounting base 18b, and a nut 14 (not shown) is screwed onto the stud bolt 11, whereby the wheel 14 is fastened to the inner hub 5 via the outer rotor 18. Note that the outer rotor 18 and the inner hub 5 are Prior to the mounting of the wheel 14, the stud bolt 11 is fastened by a bolt (not shown) different from the stud bolt 11, and the screwing of the stud bolt 11 and the nut is released when the wheel 14 is replaced. At times, care is taken to prevent the outer rotor 18 from falling off the inner hub 5 inadvertently. The

  In the in-wheel motor according to the present embodiment, the brake disc 12 is fixed to the outer peripheral side of the outer rotor 18, whereby the brake disc 12 is configured integrally with the outer rotor 18. That is, in this embodiment, the brake disc 12 is formed in a ring shape having an inner peripheral portion and an outer peripheral portion, as shown in FIG. 1, and is formed in a flange shape from the wall portion 18c of the outer rotor 18 on this inner peripheral portion. The formed brake disk mounting portion 18d is superposed, and the outer rotor 18 and the brake disk 12 are fixed by a plurality of bolts 18a (see FIGS. 2 and 3).

The brake disc 12 is a general outer diameter (for example, 15 inches or 16 inches) used in a normal automobile.
As shown in FIG. 2, the knuckle 3 is formed with a brake caliper attachment portion 3c, and the brake caliper 16 is attached to the brake caliper attachment portion 3c with a bolt 3d.

Here, the brake caliper 16 has a well-known structure, and a brake pad (not shown) provided in the caliper 16 is held between the brake disks 12 by hydraulic pressure supplied via a brake hose (not shown). Thus, a braking force is applied to stop the rotation of the wheel 14.
Next, the interior of the motor will be described. A large number of coils (not shown) are arranged in the circumferential direction in the stator 8, and a number of magnets (not shown) are arranged in the circumferential direction in the outer rotor 18. ing.

  Further, the outer peripheral surface of these coils and the inner peripheral surface of the magnet face each other with a slight gap. An angle sensor (not shown) for detecting the rotation angle of the outer rotor 18 is installed in the stator 8, and rotation information (that is, wheel speed) of the outer rotor 18 is transmitted from the angle sensor to a controller installed on the vehicle body side. Is output. Further, each coil of the stator 8 is electrically connected to an inverter installed on the vehicle body side, and power is exchanged with a battery.

Since the in-wheel motor according to one embodiment of the present invention is configured as described above, in a vehicle equipped with this in-wheel motor, for example, during traveling, the inverter is supplied to the inverter based on the detection information from the angle sensor. A control signal is set and electric power is sequentially supplied to each coil of the stator 8. The rotational force to the outer rotor 18 occurs magnetic field between the magnet along with the excitation of the coil, i.e., the motor torque is generated, the brake disk 12, the wheel 14 and the inner hub 5 is a rotation axis L1 integrally and It rotates on the same axis as the center and transmits driving force to the front wheels.

In addition, the controller adjusts the power supplied to the coil based on the driver's accelerator operation amount, thereby realizing travel according to the accelerator operation (power running control), while the regenerative power generated in the coil is reduced during vehicle deceleration. A battery (not shown) is charged (regenerative control).
Next, a description will be given of changes made on the suspension side in order to provide the in-wheel motor according to the present embodiment and the arrangement state of each member around the in-wheel motor.

  First, in order to install an in-wheel motor, the changes on the suspension side of a general vehicle will be described. In short, in this embodiment, the stator 8, the outer rotor 18, The in-wheel motor is installed only by adding or changing only three points of the brake disk 12 fixed to the outer periphery of the outer rotor 18.

  That is, the stator 8 is fastened together when the outer hub 7 of the hub bearing 4 is fastened to the knuckle 3, and the rotor 18 is attached to the inner hub 5 of the hub bearing 4 integrally with the brake disk 12, both of which are already fastened. It is fixed using a place. In particular, the assembly of the outer rotor 18 and the brake disc 12 has almost the same shape and volume as the conventional general brake disc assembly of a vehicle, and is exactly the same as when the conventional brake disc assembly is attached to the hub bearing 4. Installed by work.

Further, since the mounting position and size of the brake disk 12 are set to be the same as those of a normal brake disk, the caliper 16 and the caliper 16 mounting part can be used without any design change. .
Therefore, there is no need to provide a dedicated mounting portion for fixing the stator 8 and the outer rotor 18 on the suspension side, and the components of a general vehicle suspension structure are used as they are without changing the specifications, and then the stator 8 and the brake disc 12 are used. The in-wheel motor can be installed simply by adding the outer rotor 18 to which the motor is fixed. As a result, the manufacturing cost can be reduced by sharing the suspension parts.

As shown in FIG. 1, the inner hub 5 has a hole 5a formed coaxially with the rotation center L1, and this hole 5a is used when the front wheels are driven by a drive source other than the in-wheel motor. This is a hole through which the drive shaft passes (that is, when applied to a general automobile).
Further, such a configuration can avoid a situation in which the outer diameter of the outer rotor is increased, and the in-wheel motor can be applied to a wheel having a general size (for example, 14 to 17 inches). become.

In the above description, a general vehicle (automobile) is a vehicle (automobile) that travels by driving force from an engine or motor transmitted through a drive shaft (drive shaft), more specifically, an in-wheel motor. A vehicle (automobile) that travels with a driving force from other than the in-wheel motor.
Further, since the outer rotor 18 and the brake disc 12 are fastened by the bolt 18a, the brake disc 12 can be easily replaced. That is, since the brake disk 12 is gradually worn out, it may be necessary to replace it. In this case, the bolt 18a is loosened and removed from the outer rotor 18, and a new brake disk may be fastened again. Therefore, it is not necessary to replace the outer rotor 18 which is the main part of the in-wheel motor, so that the maintenance cost can be reduced.

Further, since the outer rotor 18 is fixed to the hub unit 4 by a bolt different from the hub bolt 11, there is an advantage that it is possible to prevent the outer rotor 18 and the brake disc 12 from falling during work such as replacement of the wheel 14.
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, A various deformation | transformation is possible in the range which does not deviate from the meaning of this invention. For example, a part of the outer rotor 18 may be enlarged to function as a brake disk.

It is typical sectional drawing which shows the structure of the in-wheel motor concerning one Embodiment of this invention. It is a disassembled perspective view which shows the structure of the in-wheel motor concerning one Embodiment of this invention. It is a perspective view which shows the structure of the in-wheel motor concerning one Embodiment of this invention. It is typical sectional drawing which shows the structure of the in-wheel motor devised in the process of inventing this invention.

Explanation of symbols

1 Strut 2 Lower arm 3 Knuckle 3a Knuckle hole 3b Hub mounting part 4 Hub bearing (hub unit)
5a hole 5b collar (hub)
5 Inner hub (rotating part)
6 Bearing 7 Outer race or outer hub (non-rotating part)
7a Flange 8 Stator (stator)
9 bolts 11 stud bolts (wheel bolts)
12 Brake disc 14 Wheel 18 Rotor or outer rotor (rotor)
18a Bolt 18b Mounting base 18c Wall 18d Brake disk mounting L1 Rotation axis

Claims (5)

A stator fixed to a non-rotating portion of the hub unit that rotatably supports the wheel with respect to the vehicle body;
An outer rotor fixed to the rotating portion of the hub unit and disposed on the outer peripheral side of the stator;
A brake disc fixed to the outer rotor ,
The outer rotor has a cylindrical wall portion extending so as to cover the stator, and a brake disc mounting portion formed in a flange shape extending radially outward from the wall portion,
The in-wheel motor , wherein the brake disc is fixed to the outer peripheral side of the outer rotor by superimposing the brake disc attachment portion on the inner peripheral edge of the brake disc . The in-wheel motor according to claim 1, wherein the outer rotor and the brake disc are integrated by being fastened by a bolt. The wheel is fastened to the hub unit by a hub bolt protruding from the rotating portion, and the outer rotor is fixed to the rotating portion of the hub unit by a bolt different from the hub bolt. The in-wheel motor according to claim 1 or 2. The hub unit has a flange facing the mounting surface of the wheel,
The outer rotor may be polymerized in the flange portion of the hub unit having a mounting base for mounting the outer rotor to the hub unit, the rotor inside wall portion extending so as to cover the stator from the mounting base that having a body
It characterized the this in-wheel motor according to any one of claims 1-3. The in-wheel motor according to any one of claims 1 to 4, wherein the stator, the outer rotor, and the brake disc are all located inside the wheel.

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