JP2003333711A - Automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the energy efficiency of the entire vehicle by warming up a planetary gear using the heat from a motor which is disposed to transfer the heat to the planetary gear and outputs power to a drive shaft through the planetary gear, for improved drive efficiency of the planetary gear. <P>SOLUTION: A creep torque Tcr outputted from a motor is set according to an oil temperature To (S112) if a shift position is in a drivable position, with an accelerator being off, and a brake on, and the travel condition of the vehicle is in the region to permit outputting of a creep torque (S100-S104), while the oil temperature To of a lubricator that lubricates the planetary gear is equal to or above a prescribed temperature Toref and an SOC of a secondary battery which supplies power to the motor is equal to or above a prescribed amount Sref. The creep torque Tcr is so set as to rise as the oil temperature To falls. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile, and more particularly, to an automobile provided with an electric motor capable of outputting power to a drive shaft connected to drive wheels.

[0002]

2. Description of the Related Art Conventionally, as a vehicle of this type, mechanical power such as a power transmission mechanism for outputting power from an electric motor to a drive shaft and transmitting power from the electric motor to the drive shaft by mechanical driving. Drives equipped with a drive mechanism, or those that output power from the internal combustion engine and electric motor to the drive shaft, distribute the power from the internal combustion engine to the electric motor or drive shaft, and output the power from the internal combustion engine and the electric motor. There has been proposed a device including a mechanical drive mechanism such as a power distribution integration mechanism that integrates the power of the above and outputs to the drive shaft. In these automobiles, the motive power from the electric motor can be output to the drive shaft, so that a desired creep torque can be output to the drive shaft by adjusting the current supply to the electric motor. Therefore, by suppressing the creep torque to a low torque according to the amount of depression of the brake pedal while the vehicle is stopped, it is possible to reduce power consumption and improve energy efficiency.

[0003]

However, in these automobiles, the efficiency of the vehicle as a whole may be low. Since the mechanical drive mechanism described above has different drive efficiency depending on its temperature, if the creep torque is controlled in the same manner as in the normal state when the temperature of the mechanical drive mechanism is low, the drive efficiency of the mechanical drive mechanism is significantly reduced. As a result, the efficiency of the vehicle as a whole also becomes low.

An object of the vehicle of the present invention is to solve these problems and to promote warming up of a mechanical drive mechanism to further improve the energy efficiency of the entire vehicle.

[0005]

Means for Solving the Problem and Its Action / Effect The vehicle of the present invention has adopted the following means in order to achieve the above-mentioned object.

An automobile of the present invention is an automobile provided with an electric motor capable of outputting power to a drive shaft connected to drive wheels, wherein a mechanical drive mechanism arranged so as to be able to transfer heat to the electric motor and the mechanical drive mechanism. Temperature detecting means for detecting the temperature of the lubricating medium supplied to the drive mechanism, creep torque setting means for setting the creep torque to be output from the electric motor based on the detected temperature, and the set creep torque are And a drive control means for controlling the drive of the electric motor so that the electric power is output.

In the motor vehicle of the present invention, the temperature detecting means supplies the temperature of the lubricating medium supplied to the electric motor capable of outputting power to the drive shaft connected to the drive wheels and the mechanical drive mechanism arranged for heat transfer. Is detected, and the creep torque setting means sets the creep torque to be output from the electric motor based on the detected temperature. And the drive control means
The electric motor is driven and controlled so that the set creep torque is output. Therefore, the creep torque output to the drive shaft is controlled in consideration of the temperature of the lubricating medium, that is, the driving efficiency of the mechanical drive mechanism lubricated by the lubricating medium.
The energy efficiency of the entire vehicle can be further improved.

Further, in the vehicle of the present invention, the creep torque setting means is a means for setting the creep torque such that the creep torque tends to increase as the temperature of the lubricating medium detected by the temperature detecting means decreases. You can also In this case, warming of the mechanical drive mechanism can be promoted when the temperature of the lubricating medium is low, so that the drive efficiency of the mechanical drive mechanism can be improved and the efficiency of the entire vehicle can be further improved.

Further, the vehicle of the present invention comprises a secondary battery capable of exchanging electric power with the electric motor and a residual capacity detecting means for detecting a residual capacity of the secondary battery, and the creep torque setting means. Is means for setting the creep torque based on the temperature of the lubricating medium detected by the temperature detecting means when the remaining capacity of the secondary battery detected by the remaining capacity detecting means is a predetermined amount or more. Can also be This can prevent the secondary battery from being over-discharged.

Further, in the automobile of the present invention, an internal combustion engine capable of outputting power is provided, and the mechanical drive mechanism is connected to the output shaft of the internal combustion engine, the output shaft of the electric motor, and the drive shaft. A three-axis power input / output mechanism that has a shaft, and any two of the three shafts can rotate independently, and the remaining one shaft rotates depending on the rotation of the two shafts. You can also

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram showing an outline of a configuration of an automobile 20 which is an embodiment of the present invention. The automobile 20 of the embodiment is, as shown in the drawing, the automobile 20 of the embodiment.
As shown in the figure, the engine 22, the planetary gear 30 connected to the crankshaft 24 as the output shaft of the engine 22, the motor 40 capable of generating electricity connected to the planetary gear 30, and the planetary gear 30 and the differential Drive wheel 6 via gear 64
CVT5 as a continuously variable transmission connected to 6a and 66b
0 and a hybrid electronic control unit (hereinafter referred to as hybrid ECU) 70 that controls the entire device
It is configured as a hybrid vehicle including.

The engine 22 is an internal combustion engine capable of outputting power by a hydrocarbon fuel such as gasoline or light oil. The crankshaft 24 of the engine 22 generates electric power to be supplied to an auxiliary device (not shown). The starter motor 26 that starts the engine 22 uses the belt 28.
Connected through. The operation control of the engine 22, such as fuel injection control, ignition control, and intake air amount adjustment control, is performed by an engine electronic control unit (hereinafter referred to as engine EC
29). Engine ECU2
9 communicates with the hybrid ECU 70, and controls the operation of the engine 22 by a control signal from the hybrid ECU 70 and outputs data regarding the operating state of the engine 22 to the hybrid ECU 70 as necessary.

The planetary gear 30 includes a sun gear 31 as an external gear, a ring gear 32 as an internal gear arranged concentrically with the sun gear 31, a first pinion gear 33 meshing with the sun gear 31, the first pinion gear 33 and the ring gear. A three-axis power input / output mechanism that includes a second pinion gear 34 that meshes with 32 and a carrier 35 that rotatably and revolvably holds the sun gear 31, the ring gear 32, and the carrier 35 as rotating elements to perform a differential action. is there. The engine 2 is attached to the sun gear 31 of the planetary gear 30.
The rotary shaft 41 of the motor 40 is coupled to the carrier 35 of the second crankshaft 24, and the output can be exchanged between the engine 22 and the motor 40 via the sun gear 31 and the carrier 35. The carrier 35 can be connected to the input shaft 51 of the CVT 50 by the clutch C1 and the clutch C2 by the clutch C2. By connecting the clutch C1 and the clutch C2 to each other, the sun gear 31, the ring gear 32, and the carrier 35 can be connected to each other. The differential between the two rotating elements is prohibited to form an integral rotating body, that is, the crankshaft 24 of the engine 22, the rotating shaft 41 of the motor 40, and the input shaft 51 of the CVT 50 are integral rotating bodies. The planetary gear 30 is also provided with a brake B1 that fixes the ring gear 32 to the case 39 and prohibits its rotation.

The motor 40 is, for example, a well-known synchronous generator motor that can be driven as a generator and also as an electric motor, and exchanges electric power with a secondary battery 44 via an inverter 43. The motor 40 is a motor electronic control unit (hereinafter referred to as a motor ECU) 4
9 is driven and controlled, and the motor ECU 49 is
A signal necessary for driving and controlling the motor 40, a signal necessary for managing the secondary battery 44, for example, a signal from a rotational position detection sensor 45 that detects the rotational position of the rotor of the motor 40, and a current sensor (not shown). The phase current applied to the motor 40 detected by the sensor 40, the inter-terminal voltage from the voltage sensor 46 arranged between the terminals of the secondary battery 44, the secondary battery 44
The charging / discharging current from the current sensor 47 attached to the electric power line from the battery, the battery temperature from the temperature sensor 48 attached to the secondary battery 44, and the like are input.
The CU 49 outputs a switching control signal or the like to the inverter 43. In the motor ECU 49, based on the integrated value of the charging / discharging current detected by the current sensor 47 for controlling the secondary battery 44, the terminal voltage detected by the voltage sensor 46, and the like, the remaining capacity (SOC of the secondary battery 44 is ) Is calculated. The motor ECU 49
Is in communication with the hybrid ECU 70, and drives and controls the motor 40 by a control signal from the hybrid ECU 70, and if necessary, data concerning the operating state of the motor 40 and the state of the secondary battery 44 is transmitted to the hybrid EC 70.
Output to U70.

The CVT 50 has a variable groove width and a primary pulley 53 connected to the input shaft 51.
Similarly, the groove width is changeable and the secondary pulley 54 connected to the output shaft 52 as a drive shaft is
A belt 55 hung in the grooves of the primary pulley 53 and the secondary pulley 54; a first actuator 56 and a second actuator 57 that change the groove widths of the primary pulley 53 and the secondary pulley 54; Second
By changing the groove widths of the primary pulley 53 and the secondary pulley 54 by the actuator 57, the power of the input shaft 51 is steplessly changed and output to the output shaft 52. The CVT 50 is controlled by an electronic control unit for CVT (hereinafter referred to as CVT ECU) 59. This CVTECU59
Is the rotation speed Ni of the input shaft 51 from the rotation speed sensor 61 attached to the input shaft 51.
And the rotation speed No of the output shaft 52 from the rotation speed sensor 62 attached to the output shaft 52.
Is input, and a drive signal to the first actuator 56 and the second actuator 57 is output from the CVTECU 59. The CVTECU 59 is also in communication with the hybrid ECU 70, and
The gear ratio of the CVT 50 is controlled by the control signal of the U 70, and data regarding the operating state of the CVT 50 is output to the hybrid ECU 70 as needed.

The oil pump 100 includes an oil pan 102.
The lubricating oil stored in is supplied to mechanical parts such as the planetary gear 30.

Planetary gear 30, motor 40 and CVT
50 is accommodated in a single case (not shown) so that heat can be transferred, and is lubricated by the lubricating oil from the oil pump 100 and also cooled.

The hybrid ECU 70 is configured as a microprocessor centered on a CPU 72,
ROM 74 storing a processing program in addition to the CPU 72
A RAM 76 for temporarily storing data, and an input / output port and a communication port (not shown). The hybrid ECU 70 includes an oil temperature To from a temperature sensor 104 attached to an oil pan 102 and a rotation speed sensor 61.
Rotation speed Ni of the input shaft 51 from the rotation speed N and rotation speed N of the output shaft 52 from the rotation speed sensor 62
o, a shift position sensor 81 for detecting the operation position of the shift lever 80, a shift position SP, an accelerator pedal position sensor 83 for detecting the depression amount of the accelerator pedal 82, an accelerator pedal position AP,
The brake pedal position BP from the brake pedal position sensor 85 for detecting the depression amount of the brake pedal 84, the brake oil pressure Pb from the hydraulic pressure sensor 87 attached to the brake master cylinder 86, the vehicle speed V from the vehicle speed sensor 88, etc. are input to the input port. Have been entered through. Further, the hybrid ECU 70 outputs a drive signal to the clutch C1 and the clutch C2, a drive signal to the brake B1, and the like via an output port. The hybrid ECU 70, as described above, includes the engine ECU 29, the motor ECU 49, and the CVT ECU 59.
Is connected to the engine ECU via a communication port.
Various control signals and data are exchanged with the control unit 29, the motor ECU 49, and the CVTECU 59.

Further, as shown in FIG. 1, the hydraulic circuit 90 from the brake master cylinder 86 connected to the brake pedal 84 to the mechanical brakes 94a, 94b of the drive wheels 66a, 66b adjusts the hydraulic pressure of the machine. Hydraulic pressure adjusting device 9 for adjusting the braking force by the brakes 94a and 94b
Two are provided. The mechanical brakes 94a, 94
The braking force applied to the drive wheels 66a and 66b by the b is determined by the hybrid ECU 70 based on the stepping force of the brake pedal vehicle speed sensor 86 and the traveling state of the vehicle. Adjusted.

In the vehicle 20 of the embodiment constructed in this way, when the vehicle is traveling forward, that is, when the shift position SP is in the D range or the B range, the clutch C1 is engaged and the clutch C2 is disconnected, and the motor 40 is operated. Motor drive mode and clutch C to drive only by power
1 and the clutch C2 are both connected to the engine 22.
Engine driving mode in which the power of the motor 40 is added to the power of the motor 40 as needed, the clutch C1 is set to the disengaged state, and the clutch C2 is set to the connected state to take the reaction force of the torque from the engine 22 by the motor 40. As a result, the vehicle travels using the torque amplification traveling mode in which the torque is amplified for traveling. It should be noted that the brake B1 is in the disconnected state even in any running mode. Further, when the vehicle is traveling in reverse, that is, when the shift position SP is in the R range, the clutch C1 is engaged and the clutch C2 is disengaged, and the vehicle travels in a reverse traveling mode in which only the power from the motor 40 is traveled or a predetermined drive is performed. When a driving force higher than the required force is requested or when the SOC of the secondary battery 44 becomes a predetermined amount or less, the brake B1 is connected together with the clutch C1 to connect the power from the engine 22 to the driving wheels 66.
The vehicle travels in the reverse torque amplification mode transmitted to a and 66b. In each of these running modes, the motor 40
Is in a drivable state, and power can be input to and output from the planetary gear 30 by driving and controlling the motor 40.

Next, the operation of the automobile 20 of the embodiment will be described. FIG. 2 is a flowchart showing an example of the creep torque control routine executed by the hybrid ECU 70 of the vehicle 20 of the embodiment. This routine is repeatedly executed every predetermined time (for example, every 8 msec).

When the creep torque control routine is executed, the CPU 72 of the hybrid ECU 70 first causes the shift position SP detected by the shift position sensor 81 and the accelerator pedal position AP and the brake pedal position detected by the accelerator pedal position sensor 83. The brake pedal position BP detected by the sensor 85, the brake oil pressure Bp detected by the oil pressure sensor 87, the vehicle speed V detected by the vehicle speed sensor 88, the oil temperature To detected by the temperature sensor 104,
A process of reading the remaining SOC of the secondary battery 44 which is calculated by the motor ECU 49 and input by communication is executed (step S100). Then, whether or not the shift position SP is a travelable position, that is, any one of the D range, the B range, and the R range, whether the accelerator pedal position AP is in the accelerator OFF state, and the brake pedal position BP are It is determined whether or not the brake is on (step S102). When it is determined that the shift position SP is not in the travelable position, the accelerator pedal position AP is determined to be in the accelerator ON state, or the brake pedal position BP is determined to be in the brake OFF state. It is determined that the control is different from the creep torque control (step S114), and this routine is ended.

When it is determined that the shift position SP is a travelable position, the accelerator pedal position AP is the accelerator OFF state, and the brake pedal position BP is the brake ON state, the traveling state of the vehicle is It is determined whether or not it is in the creep torque output permission region (step S104). Here, the creep torque output permission region is set as a region in which the creep torque needs to be output. For example, the traveling state of the vehicle speed V, the brake pedal position BP, the brake oil pressure Pb, the performance of the motor 40, the traveling characteristic of the vehicle, and the like. It can be determined by When it is determined that the running state of the vehicle is not within the creep torque output permission region, it is determined that it is not necessary to output the creep torque, and another control different from the creep torque control (step S114), for example, regenerative control of the motor 40 is performed. Then, the energy regeneration control is performed to finish the present routine.

When the running state of the vehicle is within the creep torque output permission region, the oil temperature To of the lubricating oil is the predetermined temperature Tor.
Whether there is ef or more (step S106), the secondary battery 4
It is determined whether or not the remaining capacity SOC of No. 4 is equal to or more than the predetermined amount Sref (step S108). When it is determined that the oil temperature To is not higher than the predetermined temperature Toref, or when the oil temperature To is higher than the predetermined temperature Toref but the remaining capacity SOC is the predetermined amount Sr.
When it is determined that it is not more than ef, normal creep torque control is performed (step S110), and this routine is ended. In the normal creep torque control, for example, operation control is performed so that the motor 40 outputs a torque that is corrected from the driver required torque so as to be reduced according to the traveling state such as the vehicle speed V, the brake pedal position BP, and the brake hydraulic pressure Pb. It is done by The driver request torque is, for example, a position at which the shift position SP can travel and the accelerator pedal position AP.
Is the accelerator OFF state and the brake pedal position BP is the brake ON state, it is set as the torque required to drive the vehicle at a low speed when the brake pedal 84 is turned OFF from the vehicle stopped state.

When it is determined that the oil temperature To is equal to or higher than the predetermined temperature Toref and the remaining capacity SOC of the secondary battery 44 is equal to or higher than the predetermined amount Sref, the creep torque Tcr is set according to the oil temperature To of the lubricating oil. At the same time, the drive control of the motor 40 is performed with the set creep torque Tcr (step S112), and this routine is ended. Where the oil temperature T
In the embodiment, the setting of the creep torque Tcr according to o is performed by previously determining the relationship between the oil temperature To and the creep torque Tcr by an experiment or the like and storing it in the ROM 74 as a map. The corresponding creep torque Tcr is derived. An example of this map is shown in FIG. FIG. 4 is a diagram showing the relationship between the oil temperature To of the lubricating oil and the viscosity of the lubricating oil.

In the map of FIG. 3, the oil temperature To is the predetermined temperature T
It can be seen that the creep torque Tcr is set to gradually increase as the oil temperature To decreases when the value is equal to oref or more. If the creep torque Tcr is set to a large value and the motor 40 is drive-controlled, the motor 40 is as much as that.
Since the amount of heat generated by the motor becomes large, the planetary gear 30 arranged to be able to transfer heat to the motor 40 is warmed up. On the other hand, as shown in FIG. 4, when the oil temperature To becomes low, the viscosity of the lubricating oil rapidly increases, so that the driving resistance of the oil pump 90 that supplies the lubricating oil and the planetary gear 30 that supplies the lubricating oil increases. The driving efficiency is significantly reduced. Therefore, when the oil temperature To of the lubricating oil is low,
If the creep torque Tcr is set large and the warming of the planetary gear 30 is promoted to reduce the viscosity of the lubricating oil, the copper loss of the motor 40 increases by setting the creep torque Tcr large, but the planetary gear 30, the oil pump 90, etc. Since the driving efficiency of the vehicle can be greatly improved, the energy efficiency of the vehicle as a whole can be improved. In step S108, the planetary gear 30 is not warmed up when the state of charge SOC of the secondary battery 44 is not equal to or more than the predetermined amount Sref. This prevents the secondary battery 44 from being over-discharged by the power used for warming up. This is because.

According to the vehicle 20 of the embodiment described above, the creep torque Tcr output from the motor 40 is set to be higher as the oil temperature To of the lubricating oil is lower.
With the heat generation of 0, the planetary gear 30 arranged so as to be able to transfer heat to the motor 40 can be warmed up. As a result,
Since the lubricating oil in the planetary gear 30 can be warmed up, the drive efficiency of the planetary gear 30 and the oil pump 90 can be improved, and the energy efficiency of the entire vehicle can be further improved. Moreover, the remaining capacity SO of the secondary battery 44
When C does not exceed the predetermined amount Sref, the planetary gear 30 is not warmed up, so that the secondary battery 44 is not over-discharged.

In the automobile 20 of the embodiment, the oil temperature T of the lubricating oil is
Although the creep torque Tcr is set so as to gradually increase as the o decreases, the creep torque Tcr may be set so as to increase stepwise as the oil temperature To decreases by using a predetermined threshold value. Absent. At this time, the number of steps may be any number as long as it is two or more.

In the vehicle 20 of the embodiment, when the remaining capacity SOC of the secondary battery 44 is not less than the predetermined amount Sref, the oil temperature T
The creep torque Tcr is set based on o and the motor 4
However, since the creep torque output from the motor 40 is relatively small and the power consumption thereof is small, the oil temperature To is irrespective of the remaining capacity SOC of the secondary battery 44.
The creep torque Tcr is set based on
It does not matter even if the drive is controlled.

In the vehicle 20 of the embodiment, the planetary gear 30 capable of outputting the power from the engine 22 and the power from the motor 40 to the rotary shaft of the link gear 32 as a drive shaft is arranged at a position where heat can be transferred to the motor 40. Configured as
Although the planetary gear 30 is warmed up by setting the creep torque of the motor 40 based on the oil temperature To of the lubricating oil that lubricates the planetary gear 30, a mechanism capable of transmitting the power from the electric motor to the drive shaft and other Any structure may be adopted as long as it is arranged so as to be able to transfer heat to a mechanism for mechanically driving and has a motor capable of outputting power to the drive shaft.

Although the embodiments of the present invention have been described with reference to the embodiments, the present invention is not limited to the embodiments and various embodiments are possible without departing from the gist of the present invention. Of course, it can be implemented in.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a configuration of an automobile 20 which is an embodiment of the present invention.

FIG. 2 is a hybrid ECU 70 of the vehicle 20 according to the embodiment.
6 is a flowchart showing an example of a creep torque control routine executed by

FIG. 3 is a map showing a relationship between an oil temperature To of lubricating oil and a creep torque Tcr.

FIG. 4 is a diagram showing a relationship between an oil temperature To of lubricating oil and a viscosity.

[Explanation of symbols]

20 automobile, 22 engine, 24 crank shaft, 26 starter motor, 28 belt, 29 engine ECU, 30 power input / output mechanism, 31 sun gear,
32 ring gear, 33 first pinion gear, 34 second pinion gear, 35 carrier, 39 case, 40
Motor, 41 rotation shaft, 43 inverter, 44 secondary battery, 45 rotation position detection sensor, 46 voltage sensor, 47 current sensor, 48 temperature sensor, 49 motor ECU, 50 CVT, 51 input shaft, 5
2 Output shaft, 53 Primary pulley, 54 Secondary pulley, 55 Belt, 56
1st actuator, 56a 1st duty solenoid, 57 2nd actuator, 57a 2nd duty solenoid, 59 CVT ECU, 61 rotation speed sensor, 62 rotation speed sensor, 64 differential gear, 66a, 66b drive wheel, 70 hybrid E
CU70, 72 CPU, 74 ROM, 76 RA
M, 80 shift lever, 81 shift position sensor, 82 accelerator pedal, 83 accelerator pedal position sensor, 84 brake pedal, 85 brake pedal position sensor, 86 brake master cylinder, 87 hydraulic pressure sensor, 88 vehicle speed sensor, 90 hydraulic circuit, 92 hydraulic pressure Adjusting device, 94a, 94b mechanical brake, 100 oil pump, 102 oil pan, 1
04 Temperature sensor.

Continued front page    F term (reference) 5H115 PA11 PC06 PG04 PI16 PI29                       PU28 PV09 QE01 QE02 SE03                       SE05 TE05 TI02 TI05 TI06                       TI10 TO04 TO05

Claims (4)

[Claims] 1. A motor vehicle comprising an electric motor capable of outputting power to a drive shaft connected to drive wheels, the mechanical drive mechanism being arranged so as to be able to transfer heat to the electric motor, and supplying to the mechanical drive mechanism. Temperature detecting means for detecting the temperature of the lubricating medium, creep torque setting means for setting the creep torque to be output from the electric motor based on the detected temperature, and the set creep torque. A vehicle comprising: a drive control unit that drives and controls the electric motor. 2. The vehicle according to claim 1, wherein the creep torque setting means sets the creep torque such that the lower the temperature of the lubricating medium detected by the temperature detecting means is, the larger the tendency becomes. Automobile. 3. The automobile according to claim 1, further comprising a secondary battery capable of exchanging electric power with the electric motor, and a remaining capacity detecting means for detecting a remaining capacity of the secondary battery. The creep torque setting means sets the creep torque based on the temperature of the lubricating medium detected by the temperature detecting means when the remaining capacity of the secondary battery detected by the remaining capacity detecting means is equal to or more than a predetermined amount. A car that is a means of setting. 4. The automobile according to claim 1, further comprising an internal combustion engine capable of outputting power, wherein the mechanical drive mechanism includes an output shaft of the internal combustion engine, an output shaft of the electric motor, and the output shaft of the electric motor. Has three axes connected to the drive shaft,
Any two of the three axes can rotate independently and the remaining 1
An automobile having a three-axis power input / output mechanism in which a shaft rotates depending on the rotation of the two shafts.