Suspension device for in-wheel motor

Abstract

The present invention relates to a suspension device for an in-wheel motor, comprising a cushioning member coupled to a vehicle body and absorbing road shocks, an arm member coupled to the vehicle body and arranged vertically and coupled to the cushioning member, a support member coupled to the arm member and capable of vertical movement, a connecting member rotatably mounted to the support member and serving as a steering axis, and a fixing member mounted to the connecting member, rotating in conjunction with the connecting member, and coupled to the stator of the in-wheel motor, thereby allowing the bracket for the in-wheel motor and the bracket for the suspension to be used interchangeably, thereby reducing the load.

Description

Technology Field

[0001] The present invention relates to a suspension device for an in-wheel motor, and more specifically, to a suspension device for an in-wheel motor that can secure a degree of freedom in suspension geometry design while applying an in-wheel motor to the inner side of the wheel. Background Technology

[0002] As eco-friendly future modes of transportation, autonomous electric vehicles, as well as personal driving devices such as electric wheels, electric scooters, Segways, and electric bicycles, are being researched, developed, and manufactured for various purposes and in diverse forms.

[0003] For example, as the need for future mobility devices for quickly moving short distances in urban areas and the like increases, in-wheel motors with a motor powered by a battery built into the wheel are being released, and so-called Geo Orbital Wheels, which are forms in which a battery and motor are mounted on the wheel of a bicycle, are also being released.

[0004] For reference, the motor used in the above-mentioned in-wheel motor is a direct drive motor and is configured to include a rotor mounted inside the rim of a driving wheel and a stator positioned in the inner diameter of the rotor.

[0005] Accordingly, when current is applied to the in-wheel motor and the rotor rotates, the driving wheel and the tire mounted on the outer diameter of the rim of the driving wheel rotate, thereby enabling the vehicle to drive.

[0006] However, conventionally, when an in-wheel motor is applied, the lower arm ball joint located on the inner side of the wheel is moved inward to avoid interference. At this time, as the kingpin offset—the distance between the kingpin axis and the wheel center—increases, problems such as torque steer, which affect driving stability against external input loads, occur. Therefore, there is a need to improve this.

[0007] The background technology of the present invention is disclosed in Korean Published Patent Application No. 2021-0049288 (published May 6, 2021; Title of Invention: Wheel-integrated Suspension and Steering Device for Automobiles). The problem to be solved

[0008] The present invention was devised to improve the above-mentioned problems, and aims to provide a suspension device for an in-wheel motor that can secure the degree of freedom in suspension geometry design while applying an in-wheel motor to the inner side of the wheel. means of solving the problem

[0009] The suspension device for an in-wheel motor according to the present invention comprises: a cushioning member coupled to a vehicle body and absorbing road surface shocks; an arm member coupled to the vehicle body and arranged vertically, and coupled to the cushioning member; a support member coupled to the arm member and capable of vertical movement; a connecting member rotatably mounted to the support member and serving as a steering axis; and a fixing member mounted to the connecting member, rotating in conjunction with the connecting member, and coupled to the stator of the in-wheel motor.

[0010] The above support member is characterized by comprising: an upper support member to which an upper arm member is coupled; an upper mounting member formed on the upper support member and to which one of the connecting members is mounted; a lower support member extending downward from the upper support member and to which a lower arm member is coupled; and a lower mounting member formed on the lower support member and to which another of the connecting members is mounted.

[0011] The above connecting part is characterized by including: an upper connecting part rotatably mounted on the upper mounting part; and a lower connecting part rotatably mounted on the lower mounting part.

[0012] The above fixing part is characterized by comprising: a fixing body part having a hole formed in the center so that a wheel center passes through; one or more fixing protrusions extending from the fixing plate part and coupled to the fixer; an upper fixing part formed on the fixing body part and coupled to the upper connecting part; and a lower fixing part formed on the fixing body part, disposed to face downward from the upper fixing part, and coupled to the lower connecting part.

[0013] The upper fixing part comprises: an upper fixing projection part into which the upper connecting part is inserted, which protrudes from the fixed body part in a spaced-apart manner; and an upper fixing adjustment part coupled to the upper fixing projection part to adjust the spacing of the upper fixing projection part; and the lower fixing part comprises: a lower fixing projection part into which the lower connecting part is inserted, which protrudes from the fixed body part in a spaced-apart manner; and a lower fixing adjustment part coupled to the lower fixing projection part to adjust the spacing of the lower fixing projection part.

[0014] The above fixed part is characterized by further including a fixed steering part that extends from the above fixed body part and is connected to a steering means. Effects of the invention

[0015] The suspension device for an in-wheel motor according to the present invention is designed so that the movable axis, in which the support part moves up and down, and the steering axis, in which the connecting part rotates, are separated. Therefore, even when an in-wheel motor is applied, the kingpin offset can be reduced, thereby improving driving stability. In addition, the degree of freedom in designing the suspension geometry can be improved. Furthermore, since the fixed part is coupled to the in-wheel motor and the connecting part, the number of parts is reduced, thereby enabling weight reduction. Brief explanation of the drawing

[0016] FIG. 1 is a schematic diagram showing a suspension device for an in-wheel motor according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a suspension device for an in-wheel motor according to one embodiment of the present invention. FIG. 3 is a diagram schematically showing a dark portion according to one embodiment of the present invention. FIG. 4 is a schematic diagram showing a support member according to one embodiment of the present invention. FIG. 5 is a schematic diagram showing a connection part according to one embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing a state in which a connecting part according to one embodiment of the present invention is directly mounted to a supporting part. FIG. 7 is a cross-sectional view schematically showing a state in which a connecting part according to one embodiment of the present invention is indirectly mounted to a supporting part through an extension part. FIG. 8 is a schematic diagram showing a fixing part according to one embodiment of the present invention. FIG. 9 is a schematic diagram showing a state in which a connecting part is mounted on a fixed part according to one embodiment of the present invention. Specific details for implementing the invention

[0017] Hereinafter, an embodiment of a suspension device for an in-wheel motor according to the present invention will be described with reference to the attached drawings. In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of explanation. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intention or convention of the user or operator. Therefore, the definitions of these terms should be based on the content throughout this specification.

[0018] FIG. 1 is a schematic diagram showing a suspension device for an in-wheel motor according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view showing a suspension device for an in-wheel motor according to an embodiment of the present invention. Referring to FIG. 1 and FIG. 2, a suspension device (1) for an in-wheel motor according to an embodiment of the present invention includes a damping part (10), an arm part (20), a support part (30), a connecting part (40), and a fixing part (50).

[0019] The shock absorber (10) is combined with the vehicle body (100) and absorbs road surface shock. For example, the shock absorber (10) can absorb shock by adjusting its own length by hydraulics or a spring.

[0020] The arm (20) is connected to the vehicle body (100) and arranged vertically, and is connected to the buffer (10). For example, the arm (20) is formed as a pair of upper and lower parts, the upper part of the buffer (10) is connected to the vehicle body (100), and the lower part of the buffer (10) can be connected to either arm (20).

[0021] The support member (30) is coupled to the arm member (20) and is capable of vertical movement. For example, the arm member (20) can be mounted on the upper and lower parts of the support member (30), respectively. The support member (30) can serve as a movement axis that moves vertically in conjunction with the buffer member (10).

[0022] The connecting part (40) is rotatably mounted on the support part (30) and serves as a steering axis. For example, the connecting part (40) is mounted on the upper and lower parts of the support part (30), respectively, and a virtual line connecting the rotation centers of a pair of connecting parts (40) can serve as a steering axis.

[0023] The fixed part (50) is mounted on the connecting part (40) and rotates in conjunction with the connecting part (40). The fixed part (50) is coupled with an in-wheel motor (90). For example, the in-wheel motor (90) is mounted inside the wheel part (80) and may include a stator (91) and a rotor (92). The fixed part (50) is directly coupled to the stator (91) and is mounted on the connecting part (40), thereby eliminating the motor bracket applied to the existing in-wheel motor (90).

[0024] Accordingly, since the kingpin axis is separated into a moving axis and a steering axis in the present invention, the kingpin offset, which represents the distance from the center of the wheel part (80) or in-wheel motor (90) to the steering axis, is relatively reduced, thereby maintaining steering stability.

[0025] FIG. 3 is a schematic diagram showing an arm portion according to an embodiment of the present invention. Referring to FIG. 3, the arm portion (20) according to an embodiment of the present invention includes an upper arm portion (21) and a lower arm portion (22).

[0026] The upper arm portion (21) is coupled to the upper portion of the support portion (30). For example, the upper arm portion (21) may include an upper body portion (211), an upper body portion (212) that extends from the upper body portion (211) and is coupled to the vehicle body (100), and an upper support portion (213) that extends from the upper body portion (211) in the opposite direction to the upper body portion (212) and is coupled to the support portion (30).

[0027] The lower arm portion (22) is coupled to the lower end of the support portion (30) and connected to the buffer portion (10). For example, the lower arm portion (22) may include a lower body portion (221), a lower body portion (222) that extends from the lower body portion (221) and is coupled to the vehicle body (100), and a lower support portion (223) that extends from the lower body portion (221) in the opposite direction to the lower body portion (222) and is coupled to the support portion (30). Additionally, the lower body portion (221) or the lower body portion (222) may be provided with a lower buffer portion (224) into which the buffer portion (10) can be inserted and coupled.

[0028] FIG. 4 is a schematic diagram showing a support member according to an embodiment of the present invention. Referring to FIG. 4, a support member (30) according to an embodiment of the present invention includes an upper support member (31), an upper mounting member (32), a lower support member (33), and a lower mounting member (34). Such a support member (30) can be formed integrally.

[0029] The upper support member (31) is coupled with the upper arm member (21). For example, the upper support member (31) can be inserted into a pair of spaced-apart upper support members (213) and coupled with a bushing.

[0030] The upper mounting portion (32) is formed on the upper support portion (31), and one of the connecting portions (40) is mounted thereon. For example, the upper mounting portion (32) may protrude in the direction of the fixing portion (50) and reach the upper side of the fixing portion (50).

[0031] The lower support member (33) extends downward from the upper support member (31), and the lower arm member (22) is connected. The lower support members (33) have a symmetrical shape and are spaced apart from each other, and the lower support member (223) can be inserted between the lower ends of the lower support members (33) to be connected to the bushing.

[0032] The lower mounting portion (34) is formed on the lower support portion (33), and the other one of the connecting portions (40) is mounted. For example, the lower mounting portion (34) can connect a pair of lower support portions (33).

[0033] FIG. 5 is a schematic diagram showing a connecting part according to an embodiment of the present invention, FIG. 6 is a schematic cross-sectional view showing a state in which a connecting part according to an embodiment of the present invention is directly mounted to a support part, and FIG. 7 is a schematic cross-sectional view showing a state in which a connecting part according to an embodiment of the present invention is indirectly mounted to a support part through an extension part. Referring to FIG. 5 to FIG. 7, the connecting part (40) includes an upper connecting part (41) and a lower connecting part (42).

[0034] The upper connecting part (41) is rotatably mounted on the upper mounting part (32). For example, the upper connecting part (41) may be ball-jointed with the upper mounting part (32) and may include a spherical upper ball (411) that is rotatably mounted with the upper mounting part (32) and an upper joint shaft (412) that extends downward from the upper ball (411) and is coupled to the fixed part (50).

[0035] The lower connecting part (42) is rotatably mounted on the lower mounting part (34). For example, the lower connecting part (42) may be ball-jointed with the lower mounting part (34) and may include a spherical lower ball (421) that is rotatably mounted with the lower mounting part (34) and a lower joint shaft (422) that extends upward from the lower ball (421) and is coupled to the fixed part (50).

[0036] Meanwhile, an extension part (45) is mounted on at least one of the upper mounting part (32) and the lower mounting part (34), and at least one of the upper connecting part (41) and the lower connecting part (42) is mounted on the extension part (45). Through this extension part (45), the upper connecting part (41) and the lower connecting part (42) can be arranged coaxially.

[0037] That is, when the upper connecting part (41) and the lower connecting part (42) are directly mounted to the upper mounting part (32) and the lower mounting part (34) (see FIG. 6), it is difficult to mount the upper connecting part (41) and the lower connecting part (42) to the fixed part (50). To improve this assembly, one or more of the upper connecting part (41) and the lower connecting part (42) can be mounted to the extension part (45) (see FIG. 7). For example, the upper connecting part (41) can be directly mounted to the upper mounting part (32), and the lower connecting part (42) can be mounted to the extension part (45). When the lower connecting part (42) mounted to the extension part (45) is combined with the fixed part (50), the extension part (45) can be bolted to the lower mounting part (34).

[0038] FIG. 8 is a schematic diagram showing a fixed part according to an embodiment of the present invention, and FIG. 9 is a schematic diagram showing a state in which a connecting part is mounted on a fixed part according to an embodiment of the present invention. Referring to FIG. 8 and FIG. 9, a fixed part (50) according to an embodiment of the present invention includes a fixed body part (51), a fixed protrusion part (52), an upper fixed part (53), and a lower fixed part (54).

[0039] A hole is formed in the center of the fixed body part (51) so that the wheel center (93) passes through it. For example, the wheel center (93) can be coupled with the disk (94) and connected to the wheel part (80). A stator (91) is positioned on the outside of the disk (94), and a rotor (92) surrounding the stator (91) can be connected to the wheel center (93). The wheel center (93) is rotatably mounted to the hub (95) via a bearing, and the fixed body part (51) can be coupled to the hub (95).

[0040] One or more fixed protrusions (52) extend from the fixed plate portion (51) and are coupled with the stator (91). For example, a plurality of fixed protrusions (52) may extend radially from the edge of the fixed body portion (51), and each fixed protrusion (52) may be coupled with the stator (91) to fix the stator (91).

[0041] The upper fixing part (53) is formed on the fixed body part (51), and the upper connecting part (41) is coupled thereto. More specifically, the upper fixing part (53) may include an upper fixing projection part (531) and an upper fixing adjustment part (532).

[0042] A pair of upper fixing protrusions (531) protrude spaced apart from the fixing body (51), and an upper connecting part (41) is inserted therein. For example, a groove may be formed in the upper fixing protrusion (531) to allow the upper joint shaft (412) to be inserted therein.

[0043] The upper fixing adjustment part (532) is coupled to the upper fixing projection part (531) to adjust the spacing of the upper fixing projection part (531). For example, the upper fixing adjustment part (532) may include a bolt and a nut that are screw-coupled by penetrating the end of the upper fixing projection part (531). In addition, various coupling means capable of reducing the spacing of the upper fixing projection part (531) may be used for the upper fixing adjustment part (532).

[0044] The lower fixing part (54) is formed on the fixing body part (51), is positioned to face the lower part of the upper fixing part (53), and is coupled with the lower connecting part (42). More specifically, the lower fixing part (54) may include a lower fixing projection part (541) and a lower fixing adjustment part (542).

[0045] A pair of lower fixing protrusions (541) protrude spaced apart from the fixing body (51), and a lower connecting part (42) is inserted therein. For example, a groove may be formed in the lower fixing protrusion (541) so that a lower joint shaft (422) is inserted therein.

[0046] The lower fixing adjustment part (542) is coupled to the lower fixing projection part (541) to adjust the spacing of the lower fixing projection part (541). For example, the lower fixing adjustment part (542) may include a bolt and a nut that are screw-coupled by penetrating the end of the lower fixing projection part (541). In addition, various coupling means that can reduce the spacing of the spaced lower fixing projection part (541) may be used for the lower fixing adjustment part (542).

[0047] A fixed part (50) according to one embodiment of the present invention may further include a fixed steering part (55). The fixed steering part (55) extends from the fixed body part (51) and is connected to the steering means (110). For example, the fixed steering part (55) may be moved according to a change in the position of the steering means (110) to provide steering force to the wheel part (80).

[0048] Meanwhile, the upper connecting part (41) and the lower connecting part (41) are positioned between the stators (91) of the in-wheel motor (90). For example, the stators (91) may be arranged in a circular shape, and the upper connecting part (41) and the lower connecting part (41) may be positioned between the stators (91).

[0049] More specifically, the distance (a) between the center of rotation of the upper connecting part (41) and the center of rotation of the lower connecting part (42) can be 100 mm to 300 mm. That is, the distance (a) between the center of the upper ball (411) corresponding to the center of rotation of the upper connecting part (41) and the center of the lower ball (421) corresponding to the center of rotation of the lower connecting part (42) can be 100 mm to 300 mm and can be placed inside the stator (91).

[0050] The distance (b) between the center of rotation of the upper support member (31) and the center of rotation of the lower support member (33) is greater than or equal to the distance (a) between the center of rotation of the upper connection member (41) and the center of rotation of the lower connection member (42). That is, the upper support member (31) and the upper arm member (21) can be mounted so as to be rotatable, and the lower support member (33) and the lower arm member (22) can be mounted so as to be rotatable. At this time, the upper connection member (41) and the lower connection member (42) are designed to be positioned between the upper arm member (21) and the lower arm member (22) by setting the distance (b) between the center of rotation at the connection point between the upper support member (31) and the upper arm member (21) and the center of rotation at the connection point between the lower support member (33) and the lower arm member (22). As a result, sufficient distance is secured between the upper arm (21) and the lower arm (22), thereby suppressing the rotation of the wheel (80), so that vertical movement of the wheel (80) can be induced depending on the road surface condition.

[0051] The distance (c) between the center of the wheel center (93) of the in-wheel motor (90) and the center of rotation of the lower connecting part (42) can be 10 mm to 100 mm. In this way, driving stability can be improved by reducing the kingpin offset.

[0052] The distance (d) between the center of the wheel center (93) and the center of rotation of the lower support (33) is greater than the distance (c) between the center of the wheel center (93) and the center of rotation of the lower connection (42). As a result, the kingpin shaft can be separated into a movable shaft capable of vertical movement by the lower connection (42) and a steering shaft capable of rotational movement by the lower connection (42).

[0053] The angle between the center of rotation of the lower connecting part (42) and the center of rotation of the upper connecting part (41) is set to 0 to 30 degrees, so that the lower connecting part (42) and the upper connecting part (41) can be arranged vertically or at an angle.

[0054] The angle between the center of rotation of the lower support member (33) and the center of rotation of the upper support member (31) is set to 0 to 30 degrees, so that the lower support member (33) and the upper support member (31) can be arranged vertically or at an angle.

[0055] The assembly and operation of a suspension device for an in-wheel motor according to one embodiment of the present invention having the structure as described above are as follows.

[0056] An in-wheel motor (90) is mounted on the wheel section (80), wherein the wheel center (93) is rotatably mounted on the hub (95) via a bearing, the wheel center (93) is connected to the disc (94), and the wheel center (93) is connected to the rotor (92). The wheel center (93) is connected to the wheel section (80), and a stator (91) is positioned between the wheel center (93) and the rotor (92).

[0057] The fixed part (50) is mounted on the in-wheel motor (90). That is, the fixed body part (51) is mounted on the hub (95), and the fixed protrusion part (52) is connected to the stator (91).

[0058] When the in-wheel motor (90) and the fixed part (50) are combined, the connecting part (40) is connected to the fixed part (50). The upper connecting part (41) is rotatably mounted on the upper mounting part (32), the lower connecting part (42) is rotatably mounted on the extension part (45), and the extension part (45) is mounted on the lower mounting part (34). The upper connecting part (41) can be directly assembled to the upper mounting part (32), inserted into the upper fixing part (53), and then fixed by the tightening force of the upper fixing part (53). The lower connecting part (42) can be inserted into the lower fixing part (54), fixed by the tightening force of the lower fixing part (54), and then the extension part (45) can be mounted on the lower mounting part (34).

[0059] Meanwhile, an upper mounting portion (32) extends from the upper support portion (31) toward the fixed portion (50), and an upper arm portion (21) is rotatably mounted on the upper support portion (31). A lower arm portion (22) is rotatably mounted on a lower support portion (33) extending downward from the upper support portion (31).

[0060] When driving is performed in the above state, the fixed part (50) connected to the steering means (110) rotates with the connecting part (40) as the steering axis, thereby adjusting the steering angle. Then, as the upper arm part (21) and the lower arm part (22) move up and down according to the ground condition, the support part (30) moves up and down on the movement axis, thereby inducing the up and down movement of the wheel part (80).

[0061] In an embodiment of the present invention, the suspension device (1) for an in-wheel motor is designed such that the support member (30) moves up and down along a moving axis and the connecting member (40) rotates along a steering axis, thereby allowing for a reduction in kingpin offset even when an in-wheel motor (90) is applied, which can improve driving stability. Additionally, the degree of freedom in designing the suspension geometry can be improved. Furthermore, since the fixed member (50) is coupled to the in-wheel motor (90) and the connecting member (40), the number of parts is reduced, thereby enabling weight reduction.

[0062] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the claims below. Explanation of the symbols

[0063] 10 : Buffer section 20 : Dark section 21: Upper arm 22: Lower arm 30 : Support part 31 : Upper support part 32 : Upper mounting part 33 : Lower support part 34 : Lower mounting part 40 : Connecting part 41 : Upper connection part 42 : Lower connection part 45 : Extension part 50 : Fixed part 51 : Fixed body part 52 : Fixed protrusion part 53 : Upper fixing part 54 : Lower fixing part 55 : Fixed steering part 80 : Wheel part 90 : In-wheel motor

Claims

Claim 1 A cushioning member coupled to a vehicle body and absorbing road shock; an arm member coupled to the vehicle body and arranged vertically, and coupled to the cushioning member; a support member coupled to the arm member and capable of vertical movement; a connecting member rotatably mounted to the support member and serving as a steering axis; and a fixing member mounted to the connecting member, rotating in conjunction with the connecting member, and coupled to the stator of an in-wheel motor; wherein the support member comprises an upper support member coupled to an upper arm member; an upper mounting member formed on the upper support member and to which one of the connecting members is mounted; a lower support member extending downward from the upper support member and to which a lower arm member is coupled; and a lower mounting member formed on the lower support member and to which another of the connecting members is mounted; wherein the connecting member comprises an upper connecting member rotatably mounted to the upper mounting member; A suspension device for an in-wheel motor, comprising: a lower connecting part rotatably mounted to the lower mounting part; wherein the fixing part comprises: a fixed body part having a hole formed in the center so as to allow a wheel center to pass through; one or more fixed protrusions extending from the fixed body part and coupled to the fixer; an upper fixing part formed on the fixed body part and coupled to the upper connecting part; and a lower fixing part formed on the fixed body part, disposed to face the lower portion of the upper fixing part, and coupled to the lower connecting part. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A suspension device for an in-wheel motor according to claim 1, wherein the upper fixing part comprises: an upper fixing projection part into which the upper connecting part is inserted, which protrudes spaced apart from the fixed body part in pairs; and an upper fixing adjustment part coupled to the upper fixing projection part to adjust the spacing of the upper fixing projection part; and the lower fixing part comprises: a lower fixing projection part into which the lower connecting part is inserted, which protrudes spaced apart from the fixed body part in pairs; and a lower fixing adjustment part coupled to the lower fixing projection part to adjust the spacing of the lower fixing projection part. Claim 6 A suspension device for an in-wheel motor according to claim 1, further comprising a fixed steering part that extends from the fixed body part and is connected to a steering means.

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