JP2009293779A - Oil supply structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil supply structure can properly supply oil to a supply object part by an oil pump, even when the rotational direction of a driving force source changes. <P>SOLUTION: This oil supply structure includes the driving force source 6 can selectively change the rotational direction of output torque to the normal rotation direction and the reverse rotation direction, an output member W for generating driving force by transmitting the output torque, and the oil pump 10 for delivering the oil by being driven by the output torque, and supplies the oil delivered by the oil pump 10 to the supply object part 14. The oil pump 10 is composed of two kinds of oil pumps of a normal rotation pump 10f for delivering the oil toward the supply object part 14 when the rotational direction of the output torque is the normal rotation direction and a reverse rotation pump 10r for delivering the oil toward the supply object part 14 when the rotation direction of the output torque is the reverse rotation direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an oil supply structure in which an oil pump is driven by output torque of a driving force source and oil discharged from the oil pump is supplied to a supplied portion.

  2. Description of the Related Art In recent years, a so-called in-wheel motor type vehicle has been developed as a form of electric vehicle in which a motor is disposed in or near a wheel of the wheel and the wheel is directly driven by the motor. The in-wheel motor is provided near the wheel and directly transmits power to the wheel, so that it is not necessary to provide a power transmission mechanism such as a transmission or a differential provided in a conventional vehicle. The configuration can be simplified. One example thereof is described in Patent Document 1. The in-wheel motor described in Patent Document 1 includes a motor including a stator core, a stator coil, and a rotor, a shaft that is rotated by output torque of the motor, an oil pump that is provided at one end of the shaft, an oil passage, It has. The oil pump is configured to pump oil from the oil reservoir through the oil passage, and supply the pumped oil from the opening end to the outer periphery of the stator coil of the motor through the other oil passage.

  That is, the oil supply structure in the in-wheel motor described in Patent Document 1 sucks oil from the oil reservoir provided in the bottom of the casing of the in-wheel motor through the oil passage, and sucks the oil. The oil thus supplied is supplied from the discharge port to an oil supply portion such as a stator core through another oil passage. That is, the oil stored in the oil reservoir at the bottom is pumped up by the oil pump and supplied to the supply target portion.

  Therefore, in the in-wheel motor described in Patent Document 1, oil is supplied to the outer periphery of the stator core by the oil pump driven by the output torque of the in-wheel motor, and the stator core of the in-wheel motor is supplied by the supplied oil. In addition, the stator coil can be cooled, or gears, bearings, and the like used in the power transmission path between the motor and the wheel can be lubricated.

JP 2005-73364 A

  An in-wheel motor mounted on a vehicle as a driving force source may be changed in its rotational direction during driving in order to move the vehicle forward and backward. That is, as the traveling direction of the vehicle is switched between forward and reverse, the rotational direction of the in-wheel motor is also selected between the forward rotation direction when the vehicle is advanced and the reverse rotation direction when the vehicle is reverse. May be changed automatically.

  On the other hand, in the oil supply structure in the in-wheel motor described in Patent Document 1, the oil pump that is driven by the output torque of the in-wheel motor as described above is provided. As a type of oil pump that drives by using the power of such a driving force source, a rotary pump having a relatively simple configuration such as a trochoid (rotary) type, a gear type, or a vane type is usually used. . Therefore, when the rotation direction of the in-wheel motor changes due to switching between forward and backward movement of the vehicle, the rotation direction of the oil pump also changes accordingly, and as a result, the relationship between the suction port and the discharge port of the oil pump is switched. It will be. That is, the oil pump discharge direction is switched to be opposite.

  In this case, assuming that the capacity of the oil reservoir can be sufficiently increased, the oil in the oil reservoir can be sucked from the original discharge port (that is, when the oil pump is driven in the forward rotation direction). If such a means is provided, oil can be discharged from the original suction port even when the oil pump is driven in the reverse direction. However, in the oil supply structure of the in-wheel motor described in Patent Document 1 above, an oil reservoir must be provided in a limited space inside the casing of the in-wheel motor, and the oil pump is driven in the reverse direction. In this case, the oil is not configured to be discharged from the suction port toward the supplied portion. For this reason, for example, when the in-wheel motor is driven in the reverse direction when the vehicle is moving backward, there is a possibility that the oil supply to the supplied part by the oil pump cannot be performed appropriately.

  The present invention has been made paying attention to the above technical problem. Even when the rotational direction of the driving force source changes, the oil pump can supply oil to the supplied portion with a simple configuration. An object of the present invention is to provide an oil supply structure that can be appropriately performed.

  In order to achieve the above object, the invention of claim 1 is directed to a driving force source capable of selectively changing the rotation direction of the output torque between the normal rotation direction and the reverse rotation direction, and the output torque transmitted to the driving force. And an oil pump that is driven by the output torque and discharges oil, and supplies the oil discharged from the oil pump to the supplied part. A normal rotation pump that discharges oil toward the supplied portion when the rotation direction of the torque is a normal rotation direction, and an oil that discharges oil toward the supplied portion when the rotation direction of the output torque is a reverse rotation direction It is an oil supply structure characterized by comprising two types of oil pumps, a reverse pump.

  The invention according to claim 2 is the invention according to claim 1, wherein each of the oil pumps is provided between the driving force source and the output member, and between the output member and the oil pump. Further, the oil further comprises a one-way clutch that allows transmission of torque from the driving force source side to the output member and interrupts transmission of torque from the output member side to the driving force source. Supply structure.

  According to a third aspect of the present invention, there is provided the oil supply structure according to the first or second aspect, wherein the driving force source includes an electric motor built in a wheel of the wheel with a wheel as the output member. is there.

  According to the first aspect of the present invention, when oil is supplied to the oil supply part by the oil pump driven by the output torque of the driving force source, the oil pump includes a forward rotation pump and a reverse rotation pump. Two types of oil pumps are provided. Therefore, either the forward pump or the reverse pump is always driven by the output torque with respect to the output torque in either the forward direction or the reverse direction. Therefore, even when the driving force source rotates in either the forward rotation direction or the reverse rotation direction, the oil can be appropriately supplied to the supplied portion.

  According to the invention of claim 2, an oil pump including a forward pump and a reverse pump is provided between the driving force source and the output member, and between the oil pump and the output member. A one-way clutch that transmits torque only in the direction from the driving force source to the output member is provided. Therefore, when torque from the output member toward the driving force source is input, the torque from the output member is interrupted by the one-way clutch and is not transmitted to the driving force source. Therefore, even when a torque from the output member toward the driving force source is generated, it is possible to avoid the occurrence of drag loss of the driving force source due to the torque from the output member.

  Furthermore, in the invention of claim 2, when the rotation speed of the output member in the forward rotation direction exceeds the rotation speed of the driving force source, in other words, the output member is rotated in the forward rotation direction by power other than the driving force source, inertial force, or the like. When the rotation of the output member is stopped or when the rotation of the output member is stopped, the driving force source can be rotated in the reverse direction. That is, the output torque in the reverse direction of the driving force source in that case is interrupted by the one-way clutch and is not transmitted to the output member. Therefore, for example, although the output torque in the forward rotation direction by the driving force source is not required, when it is necessary to supply the oil to the supplied part, the driving force source is rotated in the reverse rotation direction. The pump for reverse rotation is driven by the torque in the reverse rotation direction, and the oil can be supplied to the supply target portion.

  According to the third aspect of the present invention, an oil supply structure using an electric motor installed in or near a wheel of a wheel, that is, a so-called in-wheel motor as a driving force source, is appropriately supplied to the supplied portion. Can be supplied.

  In the oil supply structure according to the present invention, the oil pump is driven by a driving force source that can be controlled by selectively changing the rotation direction of the output torque between the forward rotation direction and the reverse rotation direction. It is configured to discharge the sucked oil and supply the discharged oil to the supplied part to lubricate or cool the supplied part. As the oil pump, the rotational direction of the driving force source is normal. The oil pump dedicated to forward rotation that is driven in the case of the direction and discharges oil toward the supplied part, and the supplied part that is driven when the rotation direction of the driving force source is the reverse direction opposite to the forward direction. There are two types of oil pumps: a reverse oil pump that discharges oil toward the rear.

  The oil supply structure according to the present invention is configured to supply oil toward, for example, a supplied portion inside or outside a so-called in-wheel motor installed in a wheel of a wheel as a driving force source of a vehicle. Yes. This in-wheel motor is an electric motor (motor) that is supported by the vehicle body and directly drives the wheel. The drive mode is such that the output shaft integrated with the rotor (rotor) is directly connected to the wheel mounting portion to drive the wheel. In addition to the drive mode, a mode in which a reduction gear is interposed between the output shaft and the rotor and torque increased by the reduction gear is transmitted to the wheel may be used. The in-wheel motor is supported by the vehicle body via a knuckle arm for steering wheels such as front wheels and non-steering wheels such as rear wheels via arm members such as an upper arm and a lower arm.

  FIG. 1 schematically shows an example of an oil supply structure according to the present invention. The example shown in FIG. 1 shows a configuration in which the oil supply structure of the present invention is applied to an in-wheel motor of a vehicle. Reference numeral 1 denotes a wheel of a wheel W in the vehicle, which is composed of a wheel disc 2 and a rim 3 provided on the outer periphery thereof, and is configured to attach a tire 4 to the rim 3. An in-wheel motor 5 is disposed on the inner periphery of the wheel 1 and coaxially with the wheel 1. In other words, the in-wheel motor 5 is built in the wheel 1 of the wheel W.

  The in-wheel motor 5 is mainly for outputting a driving torque for running the vehicle, and a motor 6 such as an induction motor is housed in the casing 7. That is, the motor 6 of the in-wheel motor 5 is a driving force source of the vehicle, and the output torque is rotated in the normal rotation direction that is the rotation direction when the vehicle is advanced, and the rotation direction opposite to the normal rotation direction. It is an electric motor that can be selectively switched to the reverse rotation direction. The in-wheel motor 5 is connected to and supported by a vehicle body (not shown) via the arm member 8 by attaching the casing 7 to the arm member 8.

  An output shaft 9 for outputting the torque of the motor 6 is provided. The motor 6 and the output shaft 9 may be directly connected, or may be connected via a transmission mechanism (not shown) such as a speed reducer set to a predetermined speed ratio. The output shaft 9 is connected to a wheel hub 12 that is a wheel mounting portion via an oil pump 10 and a one-way clutch 11, and the wheel 1 is mounted on the wheel hub 12.

  The oil pump 10 is driven by transmission of the output torque of the motor 6 as a driving force source to generate hydraulic pressure, and obtains power from the outside to drive a rotating shaft (not shown). Is configured to suck oil from a suction port (not shown) and to discharge the sucked oil from a discharge port (not shown). For example, known pumps having various configurations such as a rotary pump such as a gear pump, a trochoid pump, a vane pump, and a screw pump, or a piston pump can be employed. The oil pump 10 sucks the oil stored in the oil reservoir 13 provided at the bottom of the casing 7 and discharges the oil toward the supplied portion 14 that needs to be cooled and lubricated by the oil. To supply.

  The oil sump 13 is a part that collects and stores oil that drops after being supplied to each part. Here, the oil sump 13 is provided inside the casing 7, but is installed outside the casing 7. It may be a configuration. Further, the supplied portion 14 is powered between a rotor and a coil end (both not shown) of the motor 6 or a bearing (not shown) that supports each rotating member of the in-wheel motor 5 and each rotating member. A transmission member (not shown) such as a gear that performs transmission is a place where cooling or lubrication with oil is required and oil is supplied by the oil pump 10 described above.

  The oil pump 10 according to the present invention includes a forward rotation pump 10 f that discharges oil toward the supplied portion 14 when the rotation direction of the output torque of the motor 6 that drives the oil pump 10 is the forward rotation direction, and the motor 6. When the rotation direction of the output torque is the reverse rotation direction, it is composed of two oil pumps, a reverse rotation pump 10r that discharges oil toward the supplied portion 14.

  The forward rotation pump 10f and the reverse rotation pump 10r are arranged in series on the axis of the output shaft 9 and between the motor 6 and the one-way clutch 11, and the forward rotation pump 10f has a forward rotation direction. When the oil is driven, the oil in the oil reservoir 13 is sucked from the suction port (not shown), and the sucked oil is discharged from the discharge port (not shown) to the supplied portion 14 and supplied. Yes. On the other hand, when the reverse rotation pump 10r is driven in the reverse rotation direction, the oil in the oil reservoir 13 is sucked from the suction port (not shown), and the sucked oil is supplied from the discharge port (not shown) to the supplied portion 14. It is designed to be discharged and supplied.

  As described above, the oil pump 10 for supplying oil to the supplied portion 14 includes the above-described forward rotation pump 10f and the reverse rotation pump 10r. Therefore, the rotation direction of the motor 6 is the forward rotation direction. Alternatively, in any of the reverse rotation directions, the oil pump 10 can be driven, that is, either the forward rotation pump 10f or the reverse rotation pump 10r can be driven to supply the oil to the supplied portion 14.

  Further, the one-way clutch 11 is engaged by two rotating members having a rotational speed difference in a predetermined direction to transmit torque, and is released when there is a rotational speed difference in the opposite direction. This is a clutch mechanism that does not transmit torque. Specifically, the one-way clutch 11 has the output shaft 9 connected to the input side via the oil pump 10 and the wheel 1 of the wheel W connected to the output side via the wheel hub 12. The torque is transmitted when the rotational speed of the output shaft 9 on the input side becomes equal to or higher than the rotational speed of the wheel 1 on the output side. In other words, the one-way clutch 11 allows torque transmission from the motor 6 side as a driving force source to the wheel W as an output member, and transmits torque from the wheel W side as an output member to the motor 6. It is configured to block.

  Thus, since the one-way clutch 11 which interrupts | transmits the transmission of the torque from the wheel W side to the motor 6 as mentioned above between the wheel W and the motor 6 is provided, the motor 6 is not outputting. When the vehicle is traveling in a state and the wheel W is rotating, that is, for example, when the vehicle is traveling by repulsion, or when the vehicle is traveling by the output of a power source other than the in-wheel motor 5 In this case, the transmission of power to the motor 6 can be cut off, and the occurrence of drag loss in the motor 6 can be avoided.

  Furthermore, by providing the one-way clutch 11 as described above, when the wheel W is rotating in the forward rotation direction by power other than the output of the motor 6 as described above, or the rotation of the wheel W is stopped. In this case, the motor 6 can be rotated in the reverse rotation direction to drive the reverse rotation pump 10 r to appropriately supply oil to the supplied portion 14. For example, when the driving force by the in-wheel motor 5 is requested and the motor 6 is driven, when the driving force by the in-wheel motor 5 is no longer required and the driving of the motor 6 is stopped, the wheel W becomes an inertial force or The rotation is caused by the output of a power source other than the in-wheel motor 5, or the rotation is stopped. At this time, the motor 6 that has been driven until that time may still be at a high temperature, but by rotating the motor 6 in the reverse direction as described above, the reverse pump 10r without driving the wheels W. Can only drive. Therefore, the heat generating part of the motor 6 can be cooled by the oil discharged from the reverse pump 10r, and the motor 6 can be prevented from overheating.

  FIG. 2 shows another configuration example of the in-wheel motor 5 to which the oil supply structure according to the present invention is applied. The in-wheel motor 5 shown in FIG. 1 has a configuration in which the motor 6 and the output shaft 9 are directly connected, and the output shaft 9 and the wheels W are directly connected through the oil pump 10 and the one-way clutch 11. In contrast, in the in-wheel motor 5 shown in FIG. 2, the motor 6 and the output shaft 9 are connected via a gear transmission mechanism 15, and the output shaft 9 and the wheel W are connected to the oil pump 10 and the one-way. The clutch 11 and the speed reduction mechanism 16 are connected.

  In FIG. 2, the rotor shaft (rotary shaft) 6a of the motor 6 and the output shaft 9 are arranged in parallel with each other at a predetermined distance. The rotor shaft 6a and the output shaft 9 are coupled to each other through a counter gear pair 15 that is a gear transmission mechanism so as to be able to transmit power. As in the configuration example shown in FIG. 1, the oil pump 10 including the forward pump 10f and the reverse pump 10r and the one-way clutch 11 are arranged in series on the axis of the output shaft 9. Further, a planetary gear 16 is arranged in series as a speed reduction mechanism between the one-way clutch 11 and the wheel hub 12.

  The planetary gear 16 shown in the example of FIG. 2 includes a sun gear 16s that is an external gear, a ring gear 16r that is an internal gear arranged concentrically with the sun gear 16s, and a pinion gear that meshes with the sun gear 16s and the ring gear 16r. This is a single-pinion type planetary gear mechanism having a carrier 16c that rotates and revolves as a rotating element.

  The output shaft 9 is connected to the sun gear 16 s of the planetary gear 16 via the oil pump 10 and the one-way clutch 11, and the wheel hub 12, that is, the wheel W is connected to the carrier 16 c of the planetary gear 16. On the other hand, the ring gear 16r of the planetary gear 16 is connected to a fixed portion such as the casing 7, and its rotation is fixed. Therefore, in the planetary gear 16, when the ring gear 16r is a reaction force element and the sun gear 16s is an input element, the carrier 16c is an output element, and the rotational speed of the torque input to the sun gear 16s is reduced to reduce the rotational speed from the carrier 16c. It is designed to output. Therefore, the planetary gear 16 functions as a speed reduction mechanism that reduces the output torque of the motor 6 transmitted to the output shaft 9 via the counter gear pair 15 and transmits it to the wheels W.

  Even when the oil supply structure according to the present invention is applied to the in-wheel motor 5 configured as shown in FIG. 2, as in the case of the configuration example shown in FIG. The forward pump 10f and the reverse pump 10r are provided as the oil pump 10 for supplying oil, so that the forward pump can be used regardless of whether the motor 6 rotates in the forward direction or the reverse direction. Either one of 10f and the reverse pump 10r can be driven to appropriately supply oil to the supplied portion 14.

  As described above, according to the oil supply structure of the present invention, when oil is supplied to the oil supplied portion 14 by the oil pump 10 driven by the output torque of the motor 6 of the in-wheel motor 5, As the oil pump 10, two oil pumps, a forward rotation pump 10f and a reverse rotation pump 10r, are provided. Therefore, with respect to the output torque in any of the forward and reverse rotation directions, either the forward rotation pump 10f or the reverse rotation pump 10r is always driven by the output torque. As a result, even when the motor 6 rotates in either the forward rotation direction or the reverse rotation direction, oil is discharged toward the supplied portion 14 by either the forward rotation pump 10f or the reverse rotation pump 10r. Therefore, the oil can be appropriately supplied to the supplied portion 14.

  In addition, the oil pump 10 composed of the forward pump 10f and the reverse pump 10r is provided between the motor 6 and the wheel W as described above, and the motor is interposed between the oil pump 10 and the wheel W. A one-way clutch 11 that transmits torque only in the direction from 6 to the wheel W is provided. Accordingly, for example, when torque traveling from the wheel W toward the motor 6 is input during repulsive driving or when the vehicle is driven by power other than the motor 6, transmission of the torque from the wheel W is interrupted by the one-way clutch 11. Then, it is not transmitted to the motor 6. Therefore, even when a torque from the wheel W toward the motor 6 is generated, the drag loss of the motor 6 due to the torque from the wheel W can be avoided.

  Furthermore, when the rotation speed of the wheel W in the forward rotation direction exceeds the rotation speed of the motor 6, in other words, when the wheel W rotates in the forward rotation direction by power or inertial force other than the motor 6, or the wheel W When the rotation of the motor 6 is stopped, the motor 6 can be rotated in the reverse direction. That is, the output torque in the reverse direction of the motor 6 in that case is interrupted by the one-way clutch 11 and is not transmitted to the wheels W. As a result, for example, when the output torque in the forward direction by the motor 6 is not required, but it is necessary to supply the oil to the supplied portion 14, the motor 6 is rotated in the reverse direction. The reverse rotation pump 10r is driven by the output reverse rotation torque, and oil can be supplied to the supplied portion 14. For this reason, for example, there is no request for driving force by the motor 6 as in the state immediately after the rotation of the motor 6 is stopped after being driven for a long time or at a high load. When it is necessary to continuously cool the motor 6 at a high temperature, the motor 6 is rotated in the reverse direction and the reverse pump 10r is driven to supply oil to the supplied portion 14, for example, the motor 6 High temperature parts such as the rotor and coil end can be appropriately cooled.

  Note that the present invention is not limited to the above-described specific example. In the above-described specific example, the oil supply structure according to the present invention is applied to an in-wheel motor of a vehicle. The oil supply structure according to the present invention can be applied not only to a motor but also to, for example, an electric motor used as a driving force source for an electric vehicle or a motor / generator used for a hybrid vehicle.

It is a conceptual diagram which shows typically an example of the structure which can apply the oil supply structure of this invention. It is a conceptual diagram which shows typically the other example of the structure which can apply the oil supply structure of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wheel, 5 ... In-wheel motor, 6 ... Motor (driving force source, electric motor), 9 ... Output shaft, 10 ... Oil pump, 10f ... Forward pump, 10r ... Reverse pump, 11 ... One-way clutch, 14 ... Supply part, W ... wheel (output member).

Claims (3)

A driving force source capable of selectively changing the rotation direction of the output torque between a forward rotation direction and a reverse rotation direction; an output member that generates the driving force by transmitting the output torque; and oil driven by the output torque An oil supply structure including an oil pump for discharging, and supplying oil to be supplied to the oil discharged from the oil pump;
The oil pump includes a forward rotation pump that discharges oil toward the supplied portion when the rotation direction of the output torque is a normal rotation direction, and the supplied portion when the rotation direction of the output torque is a reverse rotation direction. An oil supply structure comprising two types of oil pumps, a reverse pump that discharges oil toward Each of the oil pumps is provided between the driving force source and the output member, and torque is transmitted from the driving force source side to the output member between the output member and the oil pump. 2. The oil supply structure according to claim 1, further comprising a one-way clutch that allows the transmission of the torque from the output member side to the driving force source.   The oil supply structure according to claim 1, wherein the driving force source includes an electric motor built in a wheel of the wheel using a wheel as the output member.

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