KR20180092525A - In-wheel driving device for automobile - Google Patents

Abstract

According to the present invention, an in-wheel driving device for an automobile is disclosed. According to the present invention, the in-wheel driving device for an automobile comprises: a rotation unit connected to a wheel member coupled to a tire, and rotating along with the wheel member; a knuckle unit rotationally supporting the rotation unit, connected to a suspension system, and supporting a load transmitted to the wheel member; a case unit of which one side is fixated to a side surface of the knuckle unit, and the other side is spaced from the knuckle unit; a motor unit installed at an internal side of the case unit, and generating rotating power; a first deceleration unit installed at an internal side of the case unit along with the motor unit, and primarily reducing a speed by receiving power of the motor unit; and a second deceleration unit receiving power of the first deceleration unit to secondarily reduce a speed, wherein one side is placed at an internal side of the case unit, and the other side is connected to the rotation unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an in-

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an in-wheel drive apparatus for a vehicle, and more particularly, to an in-wheel drive apparatus for a vehicle that can protect key components related to in-wheel drive from loads transmitted from a road surface during a vehicle running.

As fossil fuels become depleted, electric vehicles are being developed that use electric energy stored in batteries instead of vehicles using fossil fuels such as gasoline and light oil to drive the motor.

The electric vehicle includes a pure electric vehicle driving a motor using only electric energy stored in a rechargeable battery, a solar battery vehicle driving a motor using a photocell, a fuel cell vehicle driving a motor using a fuel cell using hydrogen fuel , And a hybrid vehicle that uses an engine and a motor by driving an engine using fossil fuel and driving the motor using electricity.

Generally, an in-wheel drive device is a technology used for an automobile that uses electricity as a power source, such as an electric vehicle. Unlike a method in which a wheel is rotated by driving power transmitted through an engine, a mission and a drive shaft in a gasoline or diesel vehicle , And the power is transmitted directly to the wheels by the left and right drive wheels or motors disposed in the right and left and front and rear four drive wheels.

The conventional in-wheel driving apparatus has a problem in that the load transmitted from the road surface during the vehicle traveling is transmitted to the main component parts related to the in-wheel driving, thereby reducing the durability of the parts. In addition, since the lateral distance between the wheel side rotating body and the motor side rotating body is deviated from the set dimension due to the transverse load transmitted to the tire, there is a problem that the operational reliability and the durability of the parts are deteriorated due to the influence of the main parts. Therefore, there is a need to improve this.

BACKGROUND ART [0002] The background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 2011-0040459 (published on Apr. 20, 2011, entitled: In-wheel drive vehicle wheel drive system).

It is an object of the present invention to provide an in-wheel drive apparatus for a vehicle that can protect key components related to in-wheel driving from loads transmitted from a road surface when the vehicle is running.

The in-wheel drive apparatus for a vehicle according to the present invention comprises: a rotating part connected to a wheel member coupled to a tire and rotating together with a wheel member; a knuckle for rotatably supporting the rotating part and supporting a load transmitted to the wheel member, And a motor section provided inside the case section to generate a rotational power. The motor section is provided inside the case section together with the motor section, and the power of the motor section And a second deceleration unit that receives the power of the first deceleration unit and receives the power from the first deceleration unit to perform a second deceleration, one side of the first deceleration unit is located inside the case unit, and the other side of the second deceleration unit is connected to the rotation unit. .

And the rotating portion includes a hub inner ring portion fixed to the wheel member and connected to the output shaft of the second reduction portion and rotating together therewith.

The knuckle portion may include a first knuckle member located on the upper side of the rotation portion and connected to the upper suspension arm of the suspension, and a second knuckle member positioned below the rotation portion and connected to the lower suspension arm of the suspension device .

The case portion may include a motor case which is spaced apart from the knuckle portion and which surrounds the outside of the motor portion, and a speed reducer case which surrounds a part of the first and second deceleration portions and is fixed to the motor case and the knuckle portion .

And the central axis of the motor portion is disposed at a position spaced apart from the rotational center axis of the wheel member by a predetermined distance.

Further, the first deceleration section includes a sun gear connected to the drive shaft of the motor section and rotated, a planetary gear rotated around the sun gear, and a ring gear located outside the carrier and the planetary gear rotated like the planetary gear .

The second reduction portion includes a small-diameter gear shaft axially engaged with the carrier, a small-diameter gear provided in a ring shape outside the small-diameter gear shaft and rotating together with the small-diameter gear shaft, Diameter gear shaft extending from the large-diameter gear and the large-diameter gear and spline-coupled to the rotating portion.

Further, the present invention is characterized by further comprising a shock absorber which is provided at a knuckle portion spaced apart from the case portion and which is deformed in contact with the case portion to reduce an impact.

According to the present invention, there is also provided a motor control apparatus comprising a motor control section for controlling an operation of a motor section, a vehicle control section for sending a control signal for operating a motor control section, a lateral force A second control unit for deriving a weighting function in which a value before the engagement of the limit lateral force becomes zero by referring to a limit lateral force that is received in a calculated value of the first control unit and is determined in design, and a second control unit And a calculation control unit for calculating a final motor torque to be transmitted to the motor control unit by multiplying the required motor torque transmitted from the vehicle control unit to the motor control unit by the weighting function.

In the in-wheel driving apparatus for a vehicle according to the present invention, external pressure introduced through the tire is moved only through the knuckle portion, and the motor case surrounding the motor portion is provided in a state spaced apart from the knuckle portion and is not deformed by external pressure. It is possible to protect the main components related to the in-wheel driving from the load transmitted from the road surface.

Further, according to the present invention, when an excessive lateral force exceeding a threshold value occurs, the operation of the first control unit, the second control unit, and the arithmetic control unit automatically blocks the power of the motor unit, thereby preventing the parts from being damaged.

1 is a schematic view illustrating a structure of an in-wheel drive apparatus for a vehicle according to an embodiment of the present invention.
FIG. 2 is a schematic view illustrating a state in which a lateral force is applied to an in-wheel driving apparatus for a vehicle according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a normal mounting state and a deformation state due to a moment of the in-wheel driving apparatus for a vehicle according to an embodiment of the present invention.
FIG. 4 is a schematic view illustrating a state where a shock absorbing unit is installed on a knuckle according to an embodiment of the present invention.
5 is a diagram illustrating a two-degree-of-freedom bicycle model used in a first controller according to an embodiment of the present invention.
FIG. 6 is a diagram showing a symbol used when a limit lateral force is applied to an in-wheel drive apparatus for a vehicle according to an embodiment of the present invention.
7 is a graph showing a lateral force weight function used in a vehicle in-wheel driving apparatus according to an embodiment of the present invention.
8 is a block diagram of an in-wheel drive apparatus for a vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an in-wheel driving apparatus for a vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

Further, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a view schematically showing a structure of an in-wheel driving apparatus for a vehicle according to an embodiment of the present invention. FIG. 2 is a schematic view illustrating a state in which a lateral force is applied to an in-wheel driving apparatus for a vehicle according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a state in which the in-wheel driving apparatus for a vehicle according to an embodiment of the present invention is in a state of normal mounting and a state of deformation due to a moment. FIG. 4 is a cross- FIG. 5 is a diagram illustrating a two-degree-of-freedom bicycle model used in a first control unit according to an embodiment of the present invention. FIG. 7 is a graph showing a lateral force-weighting function used in an in-wheel driving apparatus for a vehicle according to an embodiment of the present invention. 8 is a block diagram of an in-wheel drive apparatus for a vehicle according to an embodiment of the present invention.

1 to 8, an in-wheel driving apparatus 1 for a vehicle according to an embodiment of the present invention includes a rotation unit 30, a knuckle unit 40, a case unit 50, a motor unit 60, The first decelerator 70 and the second decelerator 80, the shock absorber 90, the motor controller 100, the vehicle controller 102, the first controller 104, the second controller 106, And an operation control unit 108.

As shown in Fig. 1, the in-wheel drive apparatus 1 for a vehicle according to the present invention is mounted inside a front wheel of a vehicle and is directly fastened to a suspension device 20. Fig. In driving an in-wheel system in which power is transmitted in the order of the motor unit 60, the first deceleration unit 70, the second deceleration unit 80, and the wheel member 15, A stable support structure for protecting internal parts of the in-vehicle drive device (1) for a vehicle to improve noise and endurance performance is provided.

The knuckle portion 40 and the case portion 50 are made to be biased to transmit the longitudinal load and the lateral load generated at the point where the tire 10 and the road surface are in contact with each other to the front sub- Is used to directly support the wheel load, and the case part (50) is configured to be independent of the wheel load supporting role. Therefore, it is possible to prevent wear of components of the motor unit 60, the first deceleration unit 70 and the second deceleration unit 80 mounted inside the case unit 50, Thereby reducing the incidence.

The in-wheel drive system 1 for a vehicle according to an embodiment of the present invention can be used in a wheel system mounted on a front wheel and driven all the way. Therefore, it must be mounted on McPherson strut, double wishbone, multi-link, etc., which are independent suspension systems with tie rods for steering. The suspension system applied to the system of the in-wheel drive unit 1 for a vehicle according to the embodiment of the present invention is a suspension of a double wishbone modification.

A ring-shaped tire 10 is provided on the outer side of the wheel member 15 and a large-diameter gear shaft 88 of the rotation portion 30 and the second reduction portion 80 is provided on the rotation center shaft 16 of the wheel member 15. [ ). The suspension device 20 connected to the knuckle part 40 includes an upper suspension arm 22 and a low suspension arm 24 and is connected to the vehicle body.

The rotating portion 30 is connected to the wheel member 15 coupled with the tire 10 and rotates together with the wheel member 15. [ The rotation part 30 is spline-coupled with the second reduction part 80 and rotates together with the second reduction part 80 to rotate the wheel member 15. The rotating portion 30 according to one embodiment includes a hub inner ring portion 32 fixed to the wheel member 15 and connected to the output shaft of the second reduction portion 80 to rotate together with the hub inner ring portion 32, And a braking disc 34 fixed to the wheel member 15. The brake disk 34 is in the shape of a disk connected to the hub inner ring part 32 and rotated together with the hub inner ring part 32. [

The knuckle part 40 may be formed in various shapes within the technical concept of supporting the load transmitted to the wheel member 15 by being connected to the suspension device 20 and supporting the rotation part 30 in a rotatable manner. The knuckle part 40 according to one embodiment includes a first knuckle member 42 located on the upper side of the rotary part 30 and connected to the upper suspension arm 22 of the suspension device 20, And a second knuckle member 44, which is located in the lower suspension arm 24 of the suspension 20 and is connected to the lower suspension arm 24.

The upper side of the first knuckle member 42 made of a rigid body is connected to the upper suspension arm 22 and the lower side is located on the side surface of the wheel member 15 and one side of the case part 50 is fixed. The upper side of the second knuckle member 44 made of a rigid body is connected to the lower side of the first knuckle member 42 and the other side of the case portion 50 is fixed to the side surface of the second knuckle member 44. The lower side of the second knuckle member (44) is connected to the lower suspension arm (24).

The hub outer ring part 120 is fixed to the knuckle part 40 including the first knuckle member 42 and the second knuckle member 44. The hub outer ring part 120 is engaged with the hub inner ring part 40 of the rotation part 30, (32). A wheel bearing 122 is provided between the hub outer ring part 120 and the hub inner ring part 32 to support the rotation part 30 including the hub inner ring part 32 so as to be easily rotated.

Since one side of the case part 50 is fixed to the side surface of the knuckle part 40 and the other side is separated from the knuckle part 40, the load transmitted through the wheel member 15 when the vehicle is traveling, (70) and the second deceleration portion (80).

The case 50 includes a motor case 52 and a first decelerating portion 70 and a second decelerating portion 70. The motor case 52 is spaced apart from the knuckle portion 40 and surrounds the motor 60, And a speed reducer case 56 which is fixed to the motor case 52 and the knuckle portion 40 so as to surround a part of the motor unit 80.

The motor case 52 is installed so as to surround the motor unit 60 and is spaced apart from the knuckle unit 40. The motor case 52 according to one embodiment includes a motor housing 53 provided in a shape to surround the outside of the motor unit 60 and a motor cover 54 for opening and closing the opened side face of the motor housing 53 . The motor housing 53 is formed in a box shape, and the motor unit 60 is installed inside the motor housing 53. Since the resolver 110 is installed inside the motor cover 54, the maintenance work of the resolver 110 can be facilitated.

One side of the speed reducer case 56 is fixed to the motor case 52 and the other side is fixed to the knuckle part 40. The speed reducer case 56 according to the embodiment includes the reducer housing 57 which is installed to surround the small diameter gear 82 and the large diameter gear 86 of the first reduction portion 70 and the second reduction portion 80, And a speed reducer cover 58 for opening and closing the opened side face of the speed reducer housing 57. A bearing for rotatably supporting the end of the small-diameter gear shaft 84 of the second reduction portion 80 is provided inside the reducer cover 58. One side of the reducer housing 57 is fixed to the motor housing 53 and the other side is fixed to the knuckle portion 40.

On the other hand, the rotating body including the gear and the rotor 64, which rotate with the hub inner ring portion 32, is radially supported by supporting both ends of the bearing, and each bearing is fixed to the motor housing 53 and the reducer cover 58, Such as a reduction gear housing 57 or a carrier 76, to transmit the support load.

Various types of driving devices may be used within the technical concept of the motor part 60 provided inside the case part 50 to generate rotational power. The motor unit 60 according to one embodiment includes a stator 62, a rotor 64, and a drive shaft 66. The motor unit (60) is installed inside the motor case (52) of the case part (50).

A stator 62, a rotor 64, and a drive shaft 66 are provided inside the motor case 52. The stator 62 is fixed along the inner wall of the motor housing 53 forming the body of the motor case 52 and the rotor 64 is located inside the motor housing 53 separated from the stator 62. The rotor 64 is connected to the drive shaft 66 so as to be rotatable inside the motor case 52. The rotor 64 and the drive shaft 66 are rotated together with the supply of power.

The central axis 61 of the motor unit 60 is installed at a position spaced apart from the rotation center shaft 16 of the wheel member 15 by a predetermined distance. Therefore, the position of the motor unit 60 can maximize the size of the motor unit 60 while avoiding interference with chassis components during driving of the vehicle. As shown in FIG. 1, since the motor unit 60 is located on the upper side of the wheel member 15, the degree of freedom of arranging the low suspension arm 24 on the lower side of the motor unit 60 is increased.

A resolver 110 is installed on one side of the drive shaft 66 and measures the rotation of the drive shaft 66 to transmit the measured value to the first control unit 104. The resolver 110 may use various types of measuring devices within the technical idea of transmitting the position information for controlling the motor unit 60 to the first control unit 104. [

The rotation output of the rotor 64 is transmitted to the wheel member 15 via the drive shaft 66, the first reduction portion 70, the second reduction portion 80, and the rotation portion 30.

The reduction gear used in the in-wheel drive unit 1 for a vehicle includes the first reduction portion 70, which is the reduction gear of the planetary gear 74, and the second reduction portion 80, which is the counter gear, .

The drive shaft 66 provided inside the rotor 64 rotates together with the rotor 64 and the rotation of the drive shaft 66 is measured by the resolver 110 while one side of the drive shaft 66 is supported by double ball bearings. The other side of the drive shaft 66 is connected to the sun gear 72 of the first decelerator 70 to rotate the sun gear 72.

In the motor case 52, there are machined surfaces for mounting and assembling the stator 62, the bearing for supporting the rotor 64, and the resolver 110 and the stator 62. A motor cover 54 for hermetic sealing after detachment of the resolver 110 is detachably mounted on the motor housing 53. Inside the gear reducer case 56, there is a surface on which the ring gear 78 is assembled and a machined portion for bearing of the large-diameter gear 86. After completion of the assembly of the second reduction portion 80, a reduction gear cover 58 for hermetic sealing is detachably mounted on the reduction gear housing 57. Further, a rotary seal for maintaining airtightness between the large-diameter gear 86, which is a rotating body, and the speed reducer case 56, which is a fixed chain, is additionally mounted.

The motor case 52 and the speed reducer case 56 are fixed by bolts. The speed reducer case 56 surrounding the large diameter gear 86 is bolted to the knuckle portion 40 together with the hub outer ring portion 120. The hub outer ring portion 120 is located outside the knuckle portion 40 and the hub outer ring portion 120 and the knuckle portion 40 are pierced through the hub portion 40 in a state where the speed reducer case 56 is located inside the knuckle portion 40 One bolt is fastened to the speed reducer case 56.

The casing portion 50 and the motor portion 60 and the first deceleration portion 70 and the second deceleration portion 80 are not directly connected to the upper suspension arm 22 and the low suspension arm 24. [ The case portion 50 also has no additional assembled portion to be engaged with the knuckle portion 40 except at a point where it is connected to the knuckle portion 40 together with the hub outer ring. That is, except for a high-voltage cable for applying a current to the motor unit 60 and a low voltage cable for collecting signals of the resolver 110 and a temperature sensor, the case 50 and the motor unit 60 The first and second deceleration portions 70 and 80 are mounted only at a position facing the hub outer ring portion 120, and the remaining portions are all free.

The first deceleration unit 70 is installed inside the case unit 50 together with the motor unit 60 and receives the power of the motor unit 60 to perform the first deceleration. The first reduction portion 70 according to one embodiment includes a sun gear 72 that is connected to the drive shaft 66 of the motor portion 60 and rotates, a planetary gear 74 that rotates around the sun gear 72, A carrier 76 that rotatably supports the planetary gear 74 and rotates together with the planetary gear 74 and a ring gear 78 that is located outside the planetary gear 74.

The rotation center of the first reduction portion 70, which is the planetary gear set, is disposed on the same axis as the drive shaft 66 of the motor portion 60. The sun gear 72 is splined to the drive shaft 66 and the ring gear 78 is inserted into the housing portion 20 to restrict rotation. Accordingly, the sun gear 72 is connected to the motor unit 60 and rotates in the state where the ring gear 78 is fixed, so that the first deceleration unit 70 is rotated in a state where the carrier 76 is decelerated.

The drive shaft 66 is fastened to the center of the sun gear 72 and the sun gear 72 rotates together with the drive shaft 66. The planetary gear 74 meshing with the sun gear 72 rotates and revolves and the carrier 76 rotatably supporting the planetary gear 74 rotates together with the planetary gear 74. [

The ring gear 78 is located outside the planetary gear 74 and surrounds the outer periphery of the first reduction portion 70 and fixed to the reduction gear case 56 so that rotation is restrained.

The second deceleration section 80 receives the power of the first deceleration section 70 and receives a second deceleration. The second deceleration section 80 is connected to the rotation section 30 at one side of the casing section 50, Various types of decelerators can be used in the system. The second reduction portion 80 according to one embodiment includes a small diameter gear shaft 84 that is axially coupled with the carrier 76 and a small diameter gear shaft 84 that is provided in a ring shape outside the small diameter gear shaft 84, A large diameter gear 86 that rotates together with the small diameter gear 82 and has a larger diameter than the small diameter gear 82 and a large diameter gear 86 that rotates in engagement with the small diameter gear 82; And a large-diameter gear shaft 88 coupled to the hub inner ring portion 32.

The small-diameter gear shaft 84 is engaged with the carrier 76 of the first reduction portion 70 and receives power. Diameter gear 82 having a gear formed outside the small-diameter gear shaft 84. The large-diameter gear 86 engaged with the small-diameter gear 82 realizes a reduced output by the gear ratio.

The large-diameter gear shaft 88 extending from the large-diameter gear 86 is spline-coupled with the hub inner ring portion 32 and is then fixed by a fixing nut.

4, the impact absorbing portion 90 is provided on the knuckle portion 40 spaced apart from the case portion 50 and has a shape that is deformed while contacting with the case portion 50, Various shapes can be deformed inside. In the in-wheel driving apparatus 1 for a vehicle according to the present invention, when a lateral load is applied through the tire 10, the motor portion 60, the case portion 60 surrounding the first deceleration portion 70 and the second deceleration portion 80, (50) is not utilized as a transmission path for the load, so that relative deformation of the case part (50) itself does not occur. However, since the knuckle portion 40 is used as a load transmission path, relative deformation occurs. For example, knuckle deformation is generated in the lower end on the basis of the rotation center shaft 16 of the wheel member 15 in the outward direction of the vehicle, and the upper end of the rotation center shaft 16 in the inward direction of the vehicle Knuckle deformation occurs.

At this time, since the case 50 has relatively little deformation, unlike the knuckle 40, collision may occur with the knuckle 40, which is deformed in shape. Particularly, The bolt head portion having the bolt head can be the target. In order to prevent such a phenomenon, the impact absorbing portion 90 is provided at a position where interference is expected to occur when the knuckle portion 40 is deformed. The shock absorbing portion 90 according to an embodiment is formed of a material having elasticity such as rubber or urethane. After the mounting groove is formed in the knuckle portion 40, the shock absorbing portion 90 is press-fitted and fixed.

Therefore, when the knuckle part 40 is deformed by the lateral force, the impact generated between the knuckle part 40 and the head of the bolt provided in the case part 50 can be absorbed easily, and the motor part 60 The advantage of the performance design is that it has a wide range of designable areas.

If the impact absorbing portion 90 is not provided, the knuckle portion 40 deformed by the external load contacts the motor case 52 and the motor case 52 becomes a load transmission path, So that the durability of the internal parts is lowered and the vibration and noise may be increased.

The motor control unit 100 is a control unit for controlling the operation of the motor unit 60. The motor unit 60 is operated under the control of the motor control unit 100, and the rotation speed can be adjusted.

The vehicle control unit 102 is a control device that sends a control signal for operating the motor control unit 100. [ The vehicle control unit 102 transmits a demand motor torque, which is a control signal, to the motor control unit 100.

The first control unit 104 receives the speed V of the vehicle and the steering angle?, And calculates the lateral force generated in the tire 10 based on the two-degree-of-freedom bicycle model.

The second control unit 106 receives the calculated value of the first control unit 104 and derives a weighting function W by which the value before the engagement of the limit lateral force becomes 0 with reference to the limit lateral force determined in design.

The operation control unit 108 is connected to the vehicle control unit 102 and the motor control unit 100 and receives the weighting function W from the second control unit 106. The operation control unit 108 calculates the final motor torque transmitted to the motor control unit 100 by multiplying the required motor torque transmitted from the vehicle control unit 102 to the motor control unit 100 by the weighting function W. [

If a lateral load is applied through the tire 10 and the knuckle portion 40 which is a path of the load movement contacts the motor case 52 of the case portion 50 and deformation of the motor case 52 occurs, If the operation of the unit 60 is continued, there is a risk that the vibration and noise become larger due to shaft deformation and the deterioration of the durability performance is further accelerated. The power of the motor unit 60 is cut off by the operation of the motor control unit 100, the vehicle control unit 102, the first control unit 104, the second control unit 106 and the operation control unit 108, Wear and endurance performance losses can be minimized.

As shown in FIGS. 5 and 8, the first control unit 104 calculates a lateral force applied to each tire 10. As a method of calculating the lateral force of the tire 10, a two-degree-of-freedom bicycle model, which is mainly used in the turning dynamics of the vehicle, is used. The two-degree-of-freedom bike model is a linear vehicle model that assumes that the lateral force applied to the left and right wheels and the slip angle of the tire 10 are the same, ignoring the front and rear treads of the vehicle. The equation of motion for a two-degree-of-freedom bike is shown below.

식(1)

Equation (1)

식(2)

Equation (2)

In this case, M, V, I, β, γ, L_f, L_r, F_yf and F_yr are the vehicle mass, vehicle speed, yawing moment of inertia, body slip angle, yaw rate, to be.

The lateral force of the front and rear tires 10 is proportional to the slip angles α_f and α_r of the front and rear tires 10, which can be expressed by the following equation.

식(3)

Equation (3)

식(4)

Equation (4)

Here, c_f and c_r are the cornering rigidity of the front and rear tires 10, respectively. The slip angle of the front and rear tires (10) can be represented by the following equation in kinematical form.

식(5)

Equation (5)

식(6)

Equation (6)

Where σ is the steering angle. Substituting Eqs. (3) - (6) into Eqs. (1) - (2), the following equation of motion can be derived.

식(7)

Equation (7)

식(8)

Equation (8)

That is, the vehicle slip angle and the yaw rate can be calculated through the vehicle speed V and the wheel steering angle?, And in the first control unit 104 through the calculated vehicle slip angle and the equations (3) to (6) It is possible to invert the lateral force of the motor 10.

The second control unit 106 is required to shut off the power of the motor unit 60 before the system calculated by the first control unit 104 receives the lateral force and the interference between the knuckle unit 40 and the case unit 50 occurs , The limit lateral force at which the interference begins to occur is calculated to derive the weight function W. [

As shown in Fig. 6 When the limit lateral force F_ylim is applied to the tire 10, the generated displacement has the following relationship.

식(9)

Equation (9)

Here, ε_t, ε, R, and r represent displacements at the patch 10 point of the tire 10, displacement at the interference portion, radius of the tire 10, and distances from the wheel axle to the interference portion. The displacement at the interfering portion, the radius of the tire (10) and the distance to the interfering portion are determined by design, and the limit lateral force is derived as follows based on the above equation.

식(10)

Equation (10)

Where K is the system lateral stiffness and is the coefficient of proportionality between the lateral force and the displacement at the tire 10 patch point. This can be derived from the module lateral stiffness test.

 The power limitation algorithm can be constructed using the marginal lateral force and the tire 10 lateral force calculated above. Fig. 7 shows a lateral force weight function W for implementing this. The weighting function W is applied in such a manner that the motor torque command of the vehicle controller is multiplied by a variable having a value between 0 and 1 to determine the final motor torque. The value of the weighting function W is 1 when the lateral force is low enough not to cause any significant hindrance to the system when the tire 10 receives the lateral force when turning the vehicle. In this case, the motor torque command determined by the vehicle control unit 102 remains unchanged And is applied to the motor control unit 100. However, when the lateral force is equal to or higher than a certain level, the output of the motor unit 60 is gradually lowered, and the motor unit 52 (motor) is operated immediately before the interference occurs in the motor case 52 due to the deformation of the knuckle unit 40 (95% of F_yoff? F_ylim) 60 is cut off.

8 is a configuration diagram of the power transfer algorithm proposed in the present invention. The first control unit 104 receives the vehicle speed V and the steering angle?, And estimates the lateral force generated in the tire 10 through the two-degree-of-freedom bicycle model. The second control unit 106 receives the calculation value of the first control unit 104, and derives a weighting function W whose value becomes 0 before the limit lateral force is applied, by referring to the limit lateral force determined in design. Finally, the operation control unit 108 multiplies the required motor torque signal generated by the vehicle control unit 102 by the weighting function W calculated by the second control unit 106, and transmits the final motor torque to the motor control unit 100 .

Therefore, when the lateral force provided in the lateral direction of the tire 10 is low, the required motor torque value determined by the vehicle control section 102 is transmitted to the motor control section 100 as it is. Then, when approaching the limit lateral force, the value of the weighting function W gradually decreases, and the value of the weighting function W becomes zero so that the motor torque is cut off before the limit lateral force becomes. In this case, when the knuckle portion 40 is deformed and the interference with the motor case 52 occurs due to the excessive lateral load applied to the system of the in-wheel drive unit 1 for a vehicle, the power of the motor portion 60 Can be performed.

The resolver 110 provided on the driving shaft 66 of the motor unit 60 is a sensor for measuring the position of the core of the rotor 64 which is the rotor of the motor unit 60. The resolver 110 has higher mechanical strength and durability than an encoder, and thus is used as a position sensor of the motor unit 60 in fields requiring high performance and high precision driving such as electric vehicles, robots, aviation, and military equipment.

On the other hand, the system using the in-wheel drive unit 1 for a vehicle has a condition in which the temperature can rise, such as heat generated by the motor unit 60 and heat generated by friction of the brake disk 34, Lubrication is required for bearings. Mission oil (ATF) cooling and lubrication systems are applied for this purpose. The oil is flowed by the pump to cool and lubricate the motor unit 60, the first reduction unit 70 and the second reduction unit 80 while circulating. The chambers forming the lubrication system are kept airtight by the oil seal.

Hereinafter, the operating state of the in-wheel drive vehicle 1 for a vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Therefore, the knuckle part 40 and the case part 50 which are the object of the present invention are made double and the load is not transferred to the case part 50, so that the durability improvement and the vibration and noise reduction effect of the internal parts are significantly reduced.

1, the power generated by the motor unit 60 is decelerated one step at the first deceleration unit 70 including the sun gear 72 engaged with the drive shaft 66 and the planetary gear 74 . The two-stage reduction is achieved by the small-diameter gear 82 engaged with the carrier 76 rotatably supporting the planetary gear 74 and the large-diameter gear 86 rotated by engaging the small-diameter gear 82. The large-diameter gear 86 includes a large-diameter gear shaft 88, and power is transmitted to the hub inner ring portion 32 coupled to the large-diameter gear shaft 88 in a splined manner to finally drive the vehicle.

The knuckle portion 40 is coupled to a hub inner ring portion 32 which receives a vehicle load and a suspension device 20 fastened to the front subframe and serves to support the load of the vehicle. That is, the load of the wheel member 15 is transmitted to the suspension 20 including the wheel member 15, the hub inner ring portion 32, the knuckle portion 40, the upper suspension arm 22 and the low suspension arm 24, ≪ / RTI > At this time, since the structure of the knuckle portion 40 and the case portion 50 is made bi-directional, the rotation axis of the wheel member 15 and the central axis 61 of the motor portion 60 can be deformed to be substantially parallel.

2 shows a case where a lateral force is applied to the inside when the vehicle is turning. The load started at the patch point of the first tire 10 is transmitted to the knuckle portion 40 through the hub inner ring portion 32 and the wheel bearing 122 and the hub outer ring portion 120 and the load transmitted to the knuckle portion 40 Moves to the upper suspension arm (22) and the lower suspension arm (24) of the suspension (20). When a moment proportional to the distance between the tire patch point and the rotation center shaft 16, which is the point of contact between the ground and the tire 10, is generated, the entire in-vehicle wheel drive apparatus 1 is in the positive camber direction The load to be twisted counterclockwise is received.

Since the knuckle portion 40 is not an ideal rigid body, deformation occurs due to the load. At this time, a portion of the knuckle portion 40 close to the suspension device 20 is restrained by the suspension device 20 so as to remain attached. Since the knuckle portion 40 near the rotation center shaft 16 is distant from the restraint point where the movement of the knuckle portion 40 is restricted, a force to be deformed by the lateral force acts largely, Occurs.

The assembly including the motor unit 60, the first decelerating unit 70, the second decelerating unit 80, and the case unit 50 is disposed at a position facing the hub outer ring part 120, And the case portion 50 separated from the knuckle portion 40 is in a free state. Therefore, the assy comprising the motor unit 60, the first deceleration unit 70, the second deceleration unit 80, and the case unit 50 has almost no deformation because there is no path through which the load is transmitted, The displacement occurs in the entire system in the positive camber direction in substantially the same manner as in the case 16. That is, when viewed from the absolute coordinate system, both the rotation center shaft 16 and the central axis 61 of the motor unit 60 are displaced relative to the initial position due to the lateral force, but the relative displacement between the two axes is almost zero. Therefore, the load applied to the bearing supporting the rotating body of the in-wheel drive unit 1 for a vehicle does not greatly increase as compared with the initial mounting state.

In order to more easily express this, as shown in FIG. 3, the supporting structure of the in-wheel driving device 1 for a vehicle is schematically illustrated by using nodes and beam elements. A closed section consisting of six nodes represents an assembly comprising a motor unit 60, a first deceleration unit 70, a second deceleration unit 80 and a case unit 50, and the beam elements connected to the stationary unit are And a knuckle portion 40 connected to the upper suspension arm 22 and the lower suspension arm 24.

The support structure of the in-wheel drive unit 1 for a vehicle according to the present invention is such that when the moment is received by the lateral load, the motor unit 60, the first deceleration unit 70, the second deceleration unit 80, (50) is not utilized as a load transmission path, so that relative deformation of the case portion (50) does not occur. As a result, even if the vehicle body is subjected to the vehicle load, the assy comprising the motor unit 60, the first deceleration unit 70, the second deceleration unit 80, and the case unit 50, Lt; / RTI >

In this case, since each of the rotors of the in-wheel drive unit 1 for a vehicle and the bearings supporting the rotors operate under conditions similar to normal engagement conditions, the durability of each of the rotors and the bearings is improved. In addition, in case of gear tooth surface, since normal gear contact condition is almost always maintained, tooth wear can be prevented, and gear noise can be minimized when the vehicle is driven.

Also, if the knuckle portion 40, the motor portion 60, the first decelerating portion 70, the second decelerating portion 80, and the case portion 50 are double-ended, Productivity and quality can be improved. The knuckle part 40 is a chassis part, and the casing part 50 is an eco-friendly part, which is not only different in field, but also different in techniques and methods for manufacturing two parts. Therefore, when the two parts are integrated as in the prior art, the defect rate increases due to the lack of the skill and experience of the manufacturer in the manufacturing process, and the cost increases. However, such a problem can be avoided through the dualization of the two parts.

As described above, according to the present invention, the external pressure introduced through the tire 10 is moved only through the knuckle portion 40, and the motor case 52 surrounding the motor portion 60 is separated from the knuckle portion 40 So that the main component parts related to the in-wheel driving can be protected from the load transmitted from the road surface when the vehicle is driven. In addition, when excessive lateral force exceeding the threshold value occurs, the power of the motor unit 60 is automatically cut off by the operation of the first control unit 104, the second control unit 106, and the operation control unit 108, Maintenance costs can be reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims. will be. Accordingly, the true scope of the present invention should be determined by the following claims.

1: In-wheel drive device for vehicle
10: tire 15: wheel member 16: rotation center shaft 20: suspension 22: upper suspension arm 24: low suspension arm
30: rotation part 32: hub inner ring part 34: brake disk
40: knuckle part 42: first knuckle member 44: second knuckle member
50: Case 52: Motor case 53: Motor housing 54: Motor cover 56: Reducer case 57: Reducer housing 58: Reducer cover
60: motor section 61: center shaft 62: stator 64: rotor 66:
70: first reduction portion 72: sun gear 74: planetary gear 76: carrier 78: ring gear
80: second reduction portion 82: small diameter gear 84: small diameter gear shaft 86: large diameter gear 88: large diameter gear shaft
90: shock absorber
100: motor control unit 102: vehicle control unit 104: first control unit 106: second control unit 108:
110: resolver 120: hub outer ring portion 122: wheel bearing
V: speed σ: steering angle W: weighting function

Claims (9)

A rotating part connected to a wheel member coupled with the tire and rotating together with the wheel member;
A knuckle portion rotatably supporting the rotation portion and connected to the suspension device, the knuckle portion supporting a load transmitted to the wheel member;
A case part fixed on one side of the knuckle part and spaced apart from the knuckle part on the other side;
A motor unit installed inside the case unit to generate rotational power;
A first deceleration unit installed inside the case together with the motor unit and receiving a power from the motor unit to perform a first deceleration;
And a second deceleration unit that receives the power of the first deceleration unit to perform a second deceleration and has one side located inside the case unit and the other side connected to the rotation unit.
The method according to claim 1,
And the rotating portion includes a hub inner ring portion fixed to the wheel member and connected to the output shaft of the second deceleration portion and rotated together therewith.
The method according to claim 1,
The knuckle portion includes a first knuckle member positioned on the upper side of the rotation portion and connected to the upper suspension arm of the suspension device; And
And a second knuckle member located below the rotation unit and connected to the low suspension arm of the suspension unit.
4. The method according to any one of claims 1 to 3,
Wherein the case part is spaced apart from the knuckle part and is installed in a shape to surround the outside of the motor part; And
And a speed reducer case surrounding the first reduction portion and the second reduction portion and fixed to the motor case and the knuckle portion.
5. The method of claim 4,
And the central axis of the motor unit is installed at a position spaced apart from the rotation center axis of the wheel member by a predetermined distance.
6. The method of claim 5,
The first deceleration unit includes: a sun gear connected to a drive shaft of the motor unit and rotated;
A planetary gear rotated around the sun gear;
A carrier rotated with the planetary gear; And
And a ring gear located on the outer side of the planetary gear.
The method according to claim 6,
The second reduction portion includes: a small-diameter gear shaft axially coupled with the carrier;
A small-diameter gear installed in a ring shape outside the small-diameter gear shaft and rotating together with the small-diameter gear shaft;
A large-diameter gear having a larger diameter than the small-diameter gear and rotating in engagement with the small-diameter gear; And
And a large-diameter gear shaft extending from the large-diameter gear and splined to the rotating portion.
4. The method according to any one of claims 1 to 3,
And a shock absorber mounted on the knuckle portion spaced apart from the case portion and adapted to deform the shape of the knocker while contacting the case portion to reduce an impact.
4. The method according to any one of claims 1 to 3,
A motor control unit for controlling an operation of the motor unit;
A vehicle control unit for sending a control signal for operating the motor control unit;
A first controller for receiving a speed and a steering angle of a vehicle and calculating a lateral force generated in the tire based on a two-degree-of-freedom bike model;
A second controller receiving a calculation value of the first control unit and deriving a weighting function having a value of 0 before the marginal lateral force is applied with reference to a marginal lateral force determined in design; And
And an arithmetic and control unit for receiving a weighting function from the second control unit and calculating a final motor torque to be transmitted to the motor control unit by multiplying a required motor torque transmitted from the vehicle control unit to the motor control unit by the weighting function Wheel drive device for a vehicle.

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