JP5157604B2 - In-wheel motor - Google Patents

Description

  The present invention relates to an in-wheel motor, and more particularly to an in-wheel motor that efficiently cools a motor body that rotates a wheel.

2. Description of the Related Art Conventionally, an in-wheel motor that cools the motor body by supplying oil discharged from the oil pump to the motor body by driving the oil pump with the motor body that rotates the wheel is known.
For example, it is like the in-wheel motor described in Patent Document 1.

The in-wheel motor described in Patent Document 1 supplies oil discharged from the oil pump to the outer periphery of the stator core of the motor body by driving the oil pump with the motor body.
The in-wheel motor described in Patent Literature 1 discharges oil by driving the oil pump by rotation of the motor body when the wheel rotates and the vehicle is running, and the discharged oil is used as the motor. The oil supplied to the outer periphery of the stator core of the main body absorbs the heat of the motor main body and attempts to cool the motor main body.

  However, since the motor body does not rotate and the oil pump does not drive when the vehicle is stopped, the oil is not supplied to the outer periphery of the stator core of the motor body, and the motor body is not cooled.

Generally, a regenerative brake is used when braking a vehicle driven by a motor body.
During regenerative braking of the vehicle, the motor body functions as a generator and generates a regenerative current to generate heat.

  In general, if the motor body generated by the regenerative brake is not cooled when the vehicle is stopped, it is known that the motor body is overheated by the heat generation, and it is necessary to limit the amount of regeneration. is there.

Also, it is generally known that if the motor body generated by this regenerative brake is not cooled when the vehicle is stopped, the motor body will rise in temperature and become overheated when starting immediately after stopping. It is necessary to limit the acceleration force.
JP 2005-73364 A

  In view of the situation as described above, the present invention provides an in-wheel motor capable of efficiently cooling a motor body.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

An in-wheel motor according to a first aspect of the present invention includes: a motor body that rotates a wheel; a speed reducer that decelerates rotation of the motor body that is transmitted to the wheel; and an oil reservoir that stores oil. The oil pump is driven by the rotation of the motor main body and sucks and discharges the oil stored in the oil reservoir, and the oil pump and the motor main body communicate with each other and are discharged by the oil pump. A first oil passage for supplying oil to the motor body, a second oil passage for supplying oil discharged by the oil pump to the speed reducer, an accumulator connected in the middle of the first oil passage, provided between the oil pump and the connecting portion of the accumulator definitive to the first oil path, it said from the oil pump accumulator And a one-way valve is to allow the oil to flow to the motor for preventing the backflow, and a first throttle provided between the motor unit and connecting portion of the accumulator definitive in the first oil passage, the second A second throttle provided in the middle of the oil passage, and the one-way valve is disposed closer to the oil pump than the first throttle in the first oil passage .

  An in-wheel motor according to a second aspect of the present invention includes the shaft according to the first aspect, wherein the rotation of the motor main body is transmitted to rotate, and the rotation of the motor main body is transmitted to the speed reducer via the shaft. It is transmitted to the oil pump through the shaft.

  The present invention has an effect that the motor body can be efficiently cooled.

Below, the in-wheel motor 10 which is one Embodiment of the in-wheel motor which concerns on this invention using FIG. 1 and FIG. 2 is demonstrated.
In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

The in-wheel motor 10 is a drive source for the wheel 20.
As shown in FIG. 1, the in-wheel motor 10 is provided inside the wheel 20.
The inside of the wheel 20 indicates a space surrounded by the rim inner peripheral surface of the wheel 20.
The entire in-wheel motor 10 does not need to be provided inside the wheel 20, and a configuration in which a part of the in-wheel motor 10 protrudes from the inside of the wheel 20 may be used.

The in-wheel motor 10 includes a housing 100, a drive device, and an oil supply device.
The housing 100 is a member that forms a main structure of the in-wheel motor 10.
The drive device and the oil supply device are provided inside the housing 100.

  Below, the said drive device is demonstrated.

  The driving device rotates the wheel 20 and includes a motor main body 210, a shaft 220, and a speed reducer 230.

The motor main body 210 is a main part that functions as a drive source of the wheel 20 in the in-wheel motor 10.
The motor body 210 includes a motor case 211, a stator core 212, a stator coil 213, a rotor 214, and a cooling jacket 215.
The motor case 211 is a member that forms a main structure of the motor main body 210.
A stator core 212, a stator coil 213, and a rotor 214 are provided inside the motor case 211.
The cooling jacket 215 is provided so as to cover the outer periphery of the motor case 211.
The motor main body 210 is rotated by an inverter (not shown) (specifically, a three-phase alternating current is supplied to the stator coil 213 by the inverter to form a rotating magnetic field, and the rotor 214 having a permanent magnet is attracted to the rotating magnetic field. A rotating synchronous motor.

  The shaft 220 is connected to the rotor 214, and the rotation of the motor main body 210 (rotation of the rotor 214) is transmitted to rotate.

The reducer 230 decelerates and outputs the input driving force.
The reducer 230 includes a gear group (a group of a plurality of gears) to which driving force is input and a drive shaft 231 connected to the output side of the gear group.
The shaft 220 is connected to the input side of the gear group. That is, the shaft 220 is connected to the drive shaft 231 through the gear group.
The drive shaft 231 is attached to a hub (not shown), and the hub is attached to the wheel 20.

The rotation of the motor body 210 is transmitted to the speed reducer 230 via the shaft 220 and is decelerated at a predetermined reduction ratio by the gear group of the speed reducer 230.
The rotation of the motor body 210 decelerated by the gear group is output from the drive shaft 231 and transmitted to the wheel 20 through the hub. Thereby, the wheel 20 rotates.

  In addition, this invention does not specifically limit about the structure of a motor main body, or the structure of a reduction gear.

  Below, the said oil supply apparatus is demonstrated.

The oil supply device supplies oil to the drive devices (the motor main body 210 and the speed reducer 230).
The oil supply device includes an oil reservoir 310, an oil pump 320, a first oil passage 330, a second oil passage 340, a third oil passage 350, and a fourth oil passage 360.

  The oil reservoir 310 stores oil used for lubricating and cooling the motor main body 210, the speed reducer 230, and the like.

Oil pump 320 sucks and discharges oil stored in oil reservoir 310.
An input shaft (rotary shaft) of the oil pump 320 is connected to the shaft 220 so as not to rotate.
The rotation of the motor body 210 is transmitted to the oil pump 320 via the shaft 220 to drive the oil pump 320.
The oil pump 320 communicates with the oil reservoir 310, and sucks and discharges oil stored in the oil reservoir 310 when the motor main body 210 rotates and the oil pump 320 is driven.

  The input shaft of the oil pump 320 may be integrated with the shaft 220.

  Further, the present invention is not particularly limited as long as the oil pump is driven by utilizing the rotation of the motor body.

  The first oil passage 330 connects the oil pump 320 and the cooling jacket 215, and a part of the oil discharged from the oil pump 320 is conveyed through the first oil passage 330 and supplied to the cooling jacket 215.

The second oil passage 340 is formed in the shaft 220, and the remaining oil discharged from the oil pump 320 is conveyed through the second oil passage 340 and supplied to the speed reducer 230.
One end of the second oil passage 340 opens on the outer peripheral surface of the shaft 220 at a position where oil discharged from the oil pump 320 can flow into the second oil passage 340 and forms an inlet.
The other end of the second oil passage 340 is on the outer peripheral surface of the shaft 220, and the oil inside the second oil passage 340 is transferred to the speed reducer 230 (gear group of the speed reducer 230) by the centrifugal force of the shaft 220 rotated by the motor body 210. It opens to a position where it can be discharged and forms a discharge port.
The remainder of the oil discharged from the oil pump 320 flows into the second oil passage 340 through the inflow port, and is then discharged from the discharge port by the centrifugal force of the shaft 220 rotated by the motor body 210 to be reduced. 230.
Thereby, the reduction gear 230 is lubricated.

  The third oil passage 350 communicates the cooling jacket 215 and the oil reservoir 310, and the oil supplied to the cooling jacket 215 is transported through the third oil passage 350 and discharged to the oil reservoir 310.

  The fourth oil path 360 communicates the speed reducer 230 and the oil reservoir 310, and the oil supplied to the speed reducer 230 is conveyed through the fourth oil path 360 and discharged to the oil reservoir 310.

  Hereinafter, an oil circulation path in the oil supply device when the vehicle is traveling will be described.

As shown in FIG. 2, when the vehicle is traveling (when the motor main body 210 is rotating), the oil stored in the oil reservoir 310 by driving the oil pump 320 is sucked and discharged by the oil pump 320. Is done.
A part of the oil discharged by the oil pump 320 is supplied to the cooling jacket 215 via the first oil passage 330 and then discharged to the oil reservoir 310 via the third oil passage 350.
The remainder of the oil discharged by the oil pump 320 is supplied to the speed reducer 230 via the second oil passage 340 and then discharged to the oil reservoir 310 via the fourth oil passage 360.
The oil discharged to the oil reservoir 310 through the third oil passage 350 and the fourth oil passage 360 is again sucked and discharged by the oil pump 320.
As described above, oil is circulated when the vehicle is running.
When the vehicle is running, this oil circulation is repeated.

  Below, cooling of the motor main body 210 performed when the vehicle is traveling will be described.

As shown in FIG. 1, the main heat source of the motor main body 210 is a stator coil 213, and the stator coil 213 is energized to generate heat, and this heat is transmitted from the stator coil 213 to the motor case 211.
As described above, the oil supplied to the cooling jacket 215 through the first oil passage 330 absorbs the heat of the motor body 210 (motor case 211).
The oil that has risen in temperature by absorbing the heat of the motor main body 210 is cooled (circulation cooling) by dissipating heat until it is circulated and supplied to the cooling jacket 215 again.
As described above, when the vehicle is running, oil circulation is repeated between the oil reservoir 310, the cooling jacket 215, and the like. At this time, the heat absorption of the motor main body 210 by the oil and the oil circulation cooling are performed. And are repeated. Thereby, the motor main body 210 is cooled when the vehicle is traveling.

  In addition, about the place which supplies oil when supplying oil to a motor main body, although this embodiment supplied the cooling jacket 215, this invention is not limited to this, What is a place which can absorb the heat of a motor main body? That's fine. For example, oil may be supplied to the inside of the motor case (such as a stator coil).

  As shown in FIG. 1, an accumulator 331 is connected in the middle of the first oil passage 330.

A one-way valve 332 is provided at a position between the oil pump 320 and the accumulator 331 in the first oil passage 330.
The one-way valve 332 allows oil to flow from the oil pump 320 to the accumulator 331 but prevents its backflow.

  A first throttle 333 is provided at a position sandwiched between the accumulator 331 and the motor main body 210 (cooling jacket 215) in the first oil passage 330.

  A second throttle 341 is provided in the middle of the second oil passage 340.

  Below, the cooling of the motor main body 210 performed when the vehicle is stopped will be described in the order of (1) to (5).

(1) When the motor main body 210 is rotated by the inverter, the wheel 20 rotates and the vehicle travels.
The oil pump 320 is driven by the rotation of the motor body 210.

(2) Next, the oil discharged from the oil pump 320 circulates between the cooling jacket 215, the speed reducer 230, the oil reservoir 310, etc. as described above (see FIG. 2).
At this time, due to the resistance of the first throttle 333, the first pressure, which is the pressure of the oil conveyed between the oil pump 320 and the first throttle 333 in the first oil passage 330, increases.
Further, due to the resistance of the second throttle 341, the second pressure, which is the pressure of the oil conveyed between the oil pump 320 and the second throttle 341 in the second oil passage 340, increases.

(3) Next, the increased pressure is stored in the accumulator 331 as the first pressure increases.
By providing the second throttle 341, the degree of increase in the first pressure is higher than when only the first throttle 333 is provided, and the amount of oil stored in the accumulator 331 is increased.

(4) Next, when the rotation of the motor body 210 stops, the vehicle stops.
At the same time, driving of the oil pump 320 is also stopped, and supply of oil from the oil pump 320 to the first oil passage 330 and the second oil passage 340 is stopped.

(5) Next, the oil that was inside the first oil passage 330 when the vehicle stopped is transported through the inside of the first oil passage 330 and supplied to the cooling jacket 215, and the first pressure decreases. To go. As the first pressure decreases, the oil stored in the accumulator 331 is also transported through the first oil passage 330 and supplied to the cooling jacket 215.
The one-way valve 332 prevents oil from flowing to the oil pump 320 side. Thereby, when the vehicle stops, the oil present on the oil pump 320 side from the one-way valve 332 is supplied to the cooling jacket 215.
Further, since the oil is supplied to the cooling jacket 215 through the first throttle 333, the first throttle 333 becomes a resistance, and the flow rate of the oil supplied to the cooling jacket 215 is limited. As a result, when the vehicle is stopped, oil is supplied to the cooling jacket 215 over time compared to when the first throttle 333 is not provided.
The oil supplied to the cooling jacket 215 absorbs the heat of the motor body 210 and the motor body 210 is cooled.
As described above, the motor main body 210 is cooled when the vehicle is stopped.

As described above, the in-wheel motor 10 includes the motor body 210 that rotates the wheel 20, the speed reducer 230 that reduces the rotation of the motor body 210 transmitted to the wheel 20, and the oil reservoir 310 that stores oil. The oil pump 320 is driven by the rotation of the motor body 210 and sucks and discharges the oil stored in the oil reservoir 310, and the oil discharged by the oil pump 320 is a motor. A first oil passage 330 supplied to the main body 210, a second oil passage 340 for supplying the oil discharged by the oil pump 320 to the speed reducer 230, an accumulator 331 connected in the middle of the first oil passage 330, a first At a position sandwiched between the oil pump 320 and the accumulator 331 in one oil passage 330 And a one-way valve 332 that allows the oil to flow from the oil pump 320 to the accumulator 331 but prevents its backflow, and a position that is sandwiched between the accumulator 331 and the motor body 210 in the first oil passage 330. A first throttle 333 and a second throttle 341 provided in the middle of the second oil passage 340.
According to this, not only the oil that was inside the first oil passage 330 when the vehicle was stopped, but also the oil that was stored in the accumulator 331 was used for cooling the motor main body 210 when the vehicle was stopped. be able to. Further, since the second throttle 341 is provided, the amount of oil stored in the accumulator 331 is increased compared to the case where only the first throttle 333 is provided, so that more oil can be drawn when the vehicle is stopped. It can be used for cooling the motor body 210. In addition, since the one-way valve 332 is provided, oil that is closer to the oil pump 320 than the one-way valve 332 when the vehicle is stopped can be used for cooling the motor body 210 when the vehicle is stopped. Accordingly, the amount of oil that can be used for cooling the motor main body 210 when the vehicle is stopped can be increased, and the motor main body 210 can be efficiently cooled.
Further, when the vehicle is stopped, the first throttle 333 becomes a resistance, and the flow rate of oil supplied to the cooling jacket 215 is limited. Therefore, when the vehicle is stopped, the oil is supplied to the cooling jacket 215 over time, so that the time that the motor body 210 is cooled by the oil becomes longer, and the motor body 210 is efficiently cooled. Can do.

The in-wheel motor 10 includes a shaft 220 that rotates when the rotation of the motor main body 210 is transmitted. The rotation of the motor main body 210 is transmitted to the speed reducer 230 via the shaft 220 and is decelerated by the speed reducer 230. And is transmitted to the oil pump 320 through the shaft 220 to drive the oil pump 320.
That is, the rotation of the motor body 210 is transmitted to the speed reducer 230 through the shaft 220 and also transmitted to the oil pump 320.
According to this, the rotation of the motor main body 210 can be transmitted to the speed reducer 230 and the oil pump 320 with one shaft 220. Therefore, the oil pump 320 can be rationally driven, and the oil discharged from the oil pump 320 can be rationally stored in the accumulator 331 as cooling oil for the motor main body 210 when the vehicle is stopped.

The schematic block diagram which shows one Embodiment of the in-wheel motor which concerns on this invention. The block diagram which shows the circulation path | route of the oil in the in-wheel motor shown in FIG.

DESCRIPTION OF SYMBOLS 10 In-wheel motor 20 Wheel 210 Motor main body 220 Shaft 230 Reduction gear 310 Oil reservoir 320 Oil pump 330 First oil path 331 Accumulator 332 One-way valve 333 First throttle 340 Second oil path 341 Second throttle

Claims (2)

A motor body that rotates the wheel;
A speed reducer that decelerates rotation of the motor body transmitted to the wheel;
An oil reservoir in which oil is stored;
An in-wheel motor comprising:
An oil pump that is driven by rotation of the motor body and sucks and discharges oil stored in the oil reservoir;
A first oil passage that communicates the oil pump and the motor body, and supplies oil discharged by the oil pump to the motor body;
A second oil passage for supplying oil discharged by the oil pump to the speed reducer;
An accumulator connected in the middle of the first oil passage;
A one-way valve wherein the connecting portion of the accumulator definitive to the first oil path provided between the oil pump, but allows from the oil pump the oil flows into the accumulator to prevent the backflow,
A first throttle provided between the motor unit and connecting portion of the accumulator definitive in the first oil path,
A second throttle provided in the middle of the second oil passage;
Equipped with a,
The one-way valve is disposed in the first oil passage on the oil pump side than the first throttle.
In-wheel motor. Comprising a shaft that is rotated by the rotation of the motor body;
The rotation of the motor body is
Transmitted to the speed reducer via the shaft,
The in-wheel motor according to claim 1, wherein the in-wheel motor is transmitted to the oil pump via the shaft.