Kingpin steering gear with reverse self-locking function and angular module assembly

Abstract

The utility model discloses a main pin steering gear and angle module assembly with reverse self -locking function, including motor and planetary gear system, the motor will power transmission to the planetary gear system after through output shaft output, the planetary gear system is double planetary gear system, including fixed on the sun gear of input shaft, the planetary gear assembly of being located the sun gear outside, and first ring gear and second ring gear, the planetary gear assembly includes the cage type planet carrier, and the first planetary gear and second planetary gear of coaxial arrangement, first planetary gear and second planetary gear eccentric and flexible setting in the planet carrier. The utility model's beneficial effect mainly reflects: main pin steering gear forms reverse self -locking, only allows motor output torque transmission to the wheel, and the torque of wheel cannot reverse transmission to motor. Meanwhile, through the special structure of double planetary gear system forms high accuracy's zero backlash structure, alleviated the various problems of ordinary planetary gear system because of the meshing gap is big, makes steering control more accurate.

Description

Technical Field

[0001] This utility model relates to the field of automotive steering technology, and in particular to a kingpin steering system and corner module assembly with reverse self-locking function. Background Technology

[0002] As a highly integrated core component, the in-wheel motor corner module plays a crucial role in the fields of new energy vehicles and drive-by-wire chassis vehicles. With the advancement of drive-by-wire chassis technology, domestic and international vehicle manufacturers and component suppliers are continuously launching in-wheel motor prototypes and vehicles, and in-wheel motor technology is gradually developing towards modularization, integration, and lightweighting. The main feature of the in-wheel motor corner module is its ability to integrate the drive, transmission, and braking systems into the wheel hub, enabling each wheel to perform independent drive, braking, steering, and suspension functions. This technology not only improves the overall performance and energy efficiency of the vehicle but also enables new energy vehicles and drive-by-wire chassis vehicles to achieve more optimized distributed drive.

[0003] One of the key components of the hub motor corner module is the kingpin steering system. The kingpin steering chassis wheel-side configuration, by eliminating the traditional tie-rod steering system, structurally allows for a larger wheel turning angle. Combined with four-wheel independent steering control, this provides greater vehicle agility, enabling various driving functions such as stationary turning and crabbing. During operation, the motor controller in the kingpin steering system receives signals from the vehicle controller and controls the three-phase voltage of the motor providing steering power to complete the specified steering angle and realize the driver's steering intentions. Simultaneously, the corner module concept aligns better with the currently popular electric skateboard chassis concept, maximizing the use of upper cabin space through highly integrated and compact wheel-side arrangement.

[0004] Existing patent CN223266850U discloses a kingpin steering system for independent vehicle steering. Utilizing the mechanical coupling of a planetary reducer, it achieves coupling between suspension load-bearing capacity and steering load force through the connection between the suspension lug and the suspension arm, improving the integration of the independent steering system and the suspension system. This technology is practical and reliable; however, because it uses planetary gears as the reduction unit, it inevitably leads to excessive cumulative pitch errors caused by tooth profile errors (such as tooth surface bulging and tooth direction deviation) and uneven hole distribution errors in the planetary carrier. This results in uneven tooth surface contact and gap fluctuations during meshing. Furthermore, during use, there is also the problem of increased meshing clearance due to wear on the gear tooth surface and bearing raceways. Excessive clearance leads to increased load impact and further accelerated wear, reduced transmission efficiency, and less precise steering control.

[0005] Meanwhile, this technology overlooks another technical issue: how to achieve reverse self-locking of the kingpin steering system, allowing the motor to output torque to the wheels while preventing the wheels from transmitting torque back to the motor. Without reverse self-locking, random disturbances in road loads during vehicle operation can affect tire posture, causing tire rubbing, random tire swaying, and other issues, leading to steering instability, especially at high speeds where the impact of the road surface on the tires is more severe. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides a kingpin steering gear and corner module assembly with reverse self-locking function.

[0007] This utility model is achieved through the following technical solution: A kingpin steering system with reverse self-locking function, for connection to a suspension system, includes a motor housing and a reducer housing fixed to each other. The motor housing houses a motor and a motor controller, and the reducer housing houses a planetary gear train. The motor, controlled by the motor controller, transmits power to the planetary gear train via an input shaft and outputs it via an output shaft. The planetary gear train is a double planetary gear train, including a sun gear fixed on the input shaft, a planetary gear assembly located outside the sun gear, and a first ring gear and a second ring gear that mate with the planetary gear assembly. The planetary gear assembly includes a cage-type planet carrier and a first planet gear and a second planet gear coaxially arranged. The first planet gear and the second planet gear are eccentrically and flexibly disposed within the planet carrier.

[0008] Preferably, the planetary gear assembly includes pin holes located at both ends of the planet carrier, with a pin passing through each pin hole. The first planetary gear and the second planetary gear are coaxially sleeved on the pin and arranged axially. The line connecting the axis of adjacent pin holes and the axis of the planet carrier forms the central angle of the pin hole, and the central angles of adjacent pin holes are all different.

[0009] Preferably, an elastic bushing is provided in the pin hole, and adjacent elastic bushings are preloaded with opposite or opposing preload forces.

[0010] Preferably, the elastic bushing includes an outer ring, an inner ring, and an elastic element located between the two. The outer ring is fixed in the pin hole, the inner ring is fixed on the pin, and the elastic element provides the preload force.

[0011] Preferably, the teeth of the second planetary gear are arranged in an inverted conical cross section from top to bottom in the tooth width direction; the second gear ring forms a tooth inter-tooth portion with a matching inverted conical cross section in the tooth width direction.

[0012] Preferably, the speed ratio of the dual planetary gear train is greater than 350, and the transmission efficiency is less than 50%.

[0013] Preferably, an angle sensor is provided at the bottom of the reducer housing and is sleeved on the outside of the output shaft.

[0014] Preferably, the first gear ring is fixed inside the reducer housing, and the second gear ring is fixed to the output shaft to serve as power output.

[0015] Preferably, the bottom end of the output shaft is an output flange, and the output shaft is connected to the reducer housing by a bearing and a sealed cavity is formed by an oil seal.

[0016] This utility model also discloses a corner module assembly, including a wheel, a hub motor, a steering knuckle, and a kingpin steering gear as described above connected to the suspension system. The torque output end of the kingpin steering gear is connected to the first end of the steering knuckle, and the second end of the steering knuckle is connected to the wheel. The kingpin steering gear can drive the wheel to steer by driving the steering knuckle.

[0017] The main advantages of this invention are as follows: the kingpin steering system forms a reverse self-locking mechanism, allowing only the motor's output torque to be transmitted to the wheels, while the wheel's torque cannot be transmitted back to the motor. Simultaneously, the special structure of the double planetary gear train creates a high-precision, zero-backlash structure, alleviating various problems caused by large meshing clearances in ordinary planetary gear trains, thus making steering control more precise. Attached Figure Description

[0018] Figure 1 This is a structural schematic diagram of the corner module of this utility model, with the hub motor omitted; Figure 2 This is a schematic diagram of the design principle of the kingpin steering system of this utility model; Figure 3 This is a sectional view of the kingpin steering mechanism of this utility model; Figure 4 This is a schematic diagram of the planetary gear assembly of the kingpin steering system of this utility model; Figure 5 This is an exploded schematic diagram of the planetary carrier of this utility model; Figure 6 This is a top view of the planetary carrier of this utility model; Figure 7 This is a schematic diagram of the fit between the planetary gears and the gear ring after the flexible planetary carrier is adopted in this utility model; Figure 8 This is a front view of the second planetary gear of this utility model; Figure 9 This is a single-tooth sectional view of the second planetary gear of this utility model in the tooth width direction; Figure 10 This is a three-dimensional schematic diagram of the second gear ring of this utility model; Figure 11This is a cross-sectional view of the inter-tooth portion of the second gear ring of this utility model in the tooth width direction; Figure 12 This is a schematic diagram of the single-tooth engagement between the second planetary gear and the second gear ring in the tooth width direction of this utility model. Detailed Implementation

[0019] To make the objectives, advantages, and features of this utility model clearer and more detailed, the following non-limiting description of preferred embodiments will be illustrated and explained. These embodiments are merely typical examples of applying the technical solutions of this utility model; any technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by this utility model.

[0020] It should also be stated that, in the description of the solution, the terms "center", "upper", "lower", "left", "right", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Furthermore, the terms "first" and "second" in this solution are used for descriptive purposes only and should not be construed as indicating or implying a ranking of importance, or implicitly specifying the number of technical features shown. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0022] This utility model discloses a kingpin steering system 100, such as Figure 1 As shown, this is part of a corner module assembly. The corner module assembly includes a wheel 200, a hub motor (not shown), a steering knuckle 300, and a kingpin steering system 100 connected to the suspension system. The torque output end of the kingpin steering system 100 is connected to a first end of the steering knuckle 300, and the second end of the steering knuckle 300 is connected to the wheel 200. The kingpin steering system 100 can steer the wheel by driving the steering knuckle 300.

[0023] Reference Figure 2 and Figure 3As shown, the kingpin steering gear 100 includes a motor housing 1 and a reducer housing 2 fixed to each other. The motor housing 1 houses a motor 3 and a motor controller 4. The motor 3 includes a rotor 5 and a stator 6. The motor controller 4 is located on one side of the motor 3, and the two are electrically connected via a circuit board. The reducer housing 2 houses a planetary gear train, and the motor 3 extends outwards with an input shaft 7. Power is transmitted through the input shaft 7 to the planetary gear train and then output through the output shaft 13, controlled by the motor controller 4.

[0024] In a preferred embodiment of this invention, the planetary gear system is a double planetary gear system, including a sun gear 8 fixed on the input shaft 7, a planetary gear assembly located outside the sun gear 8, and a first ring gear 10 and a second ring gear 12 that mesh with the planetary gear assembly. The planetary gear assembly includes a cage-type planet carrier 15 and a first planetary gear 9 and a second planetary gear 11 coaxially arranged. Motor power is transmitted through the sun gear 8 to the meshing first planetary gear 9, driving the coaxially fixed second planetary gear 11, which in turn transmits power to the second ring gear 12 meshing with the second planetary gear 11, and then outputs power through the output shaft 13, the bottom end of which is an output flange 14. The double planetary gear system of this invention has a speed ratio greater than 350 and a transmission efficiency less than 50%. The applicant discovered that under these conditions, the kingpin steering mechanism forms a reverse self-locking mechanism, allowing only the motor output torque to be transmitted to the wheels, while the wheel torque cannot be transmitted back to the motor.

[0025] The first gear ring 10 is fixed inside the reducer housing 2, and the second gear ring 12 is fixed to the output shaft 13. The output shaft 13 is connected to the reducer housing 2 via a bearing 16, and a sealed cavity is formed by an oil seal 17.

[0026] Continue to refer to Figure 3 As shown, an angle sensor 18 is provided at the bottom of the reducer housing 2 and is sleeved on the outside of the output shaft 13. The angle sensor and the motor's built-in encoder are used for calibration. If either the angle sensor or the motor's built-in encoder fails, the other can be used as a backup to ensure the safety of the car's kingpin steering system in controlling the wheel angle.

[0027] The feature of this utility model is that the first planetary gear 9 and the second planetary gear 11 are eccentrically and flexibly disposed within the planet carrier 15. Specifically, as follows... Figures 4 to 7As shown, the cage-like planetary carrier 15 has corresponding pin holes at both ends, with a pin shaft 19 passing through each pin hole. The first planetary gear 9 and the second planetary gear 11 are coaxially sleeved on the pin shaft 19 and arranged axially. Specifically, an elastic bushing 20 is provided in the pin hole. The elastic bushing 20 includes an outer ring 201, an inner ring 202, and an elastic element 203 located between the two. The outer ring 201 is fixed in the pin hole, and the inner ring 202 is fixed on the end of the pin shaft 19. With this arrangement, the elastic element 203 allows for a certain gap between the outer ring 201 and the inner ring 202, thus forming a flexible connection between the pin shaft 19 and the planetary carrier 15.

[0028] The line connecting the axis of adjacent pin holes to the axis of planet carrier 15 forms the central angle of the pin holes. The central angles of adjacent pin holes are different, such as... Figure 6 In this preferred embodiment, the planetary gear assembly includes four pin holes. The central angles of adjacent pin holes are different, while the central angles of relative pin holes are the same. That is, the actual center of the pin holes in this invention is offset from the theoretical center of full symmetry. Specifically, as shown in the figure, pin holes A and B are closer together, while the distance between pin holes A and D, and between pin holes B and C is farther.

[0029] like Figure 7 As shown, taking pin holes A and B, which are off-center from the theoretical center and close to each other, as an example, the sun gear 8 and the first ring gear 10 are always in contact with the two side tooth surfaces of the first planet gear A and the first planet gear B, respectively. Specifically, when the sun gear rotates clockwise as shown in the figure, it performs backlash-free transmission with the first planet gear B and the first ring gear 10; when the sun gear rotates counterclockwise as shown in the figure, it performs backlash-free transmission with the first planet gear A and the first ring gear 10. That is to say, in this embodiment, regardless of which direction the sun gear rotates, there are always two planet gears performing backlash-free transmission with the sun gear and the ring gear.

[0030] Preferably, in this embodiment, the elastic element 203 is an eccentric element, so that adjacent elastic bushings 20 are pre-loaded with opposing or opposite preload forces. For example Figure 7 As shown, the first planetary gear A and the first planetary gear B tend to move in opposite directions due to the preload. When the gear teeth wear, the preload ensures that the two sides of the teeth of the first planetary gear A and the first planetary gear B always remain in contact with the sun gear 8 and the first gear ring 10, respectively.

[0031] like Figures 8 to 11 As shown, the teeth of the second planetary gear 11 are arranged with an inverted conical cross section from top to bottom in the tooth width direction, that is, the tooth thickness gradually decreases, forming a tooth thickness cone angle α; the second gear ring 12 forms a tooth inter-tooth portion with a matching inverted conical cross section in the tooth width direction, forming a conical groove with the same angle as the tooth thickness cone angle α of the second planetary gear 11. Figure 12As shown, because the kingpin steering gear is vertically mounted, under the influence of gravity, the conical teeth of the second planetary gear 11 will engage with the inter-tooth portion of the second gear ring 12. This ensures that the tooth surfaces on both sides of the gears are simultaneously engaged, thereby eliminating tooth flank backlash. This invention achieves a high-precision, zero-backlash structure through the above configuration, alleviating various problems caused by large meshing clearances in ordinary planetary gear systems, and making steering control more precise.

[0032] This utility model has many other embodiments. All technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of this utility model.

Claims

1. A kingpin steering system with reverse self-locking function for connection to a suspension system, comprising a motor housing (1) and a reducer housing (2) fixed to each other, wherein the motor housing (1) houses a motor (3) and a motor controller (4), and the reducer housing (2) houses a planetary gear train, wherein the motor (3) is controlled by the motor controller (4) to transmit power to the planetary gear train via an input shaft (7) and then outputs power via an output shaft (13), characterized in that: The planetary gear train is a double planetary gear train, including a sun gear (8) fixed on the input shaft (7), a planetary gear assembly located outside the sun gear (8), and a first gear ring (10) and a second gear ring (12) that cooperate with the planetary gear assembly. The planetary gear assembly includes a cage-type planet carrier (15), and a first planetary gear (9) and a second planetary gear (11) arranged coaxially. The first planetary gear (9) and the second planetary gear (11) are eccentrically and flexibly arranged inside the planet carrier (15).

2. The kingpin steering gear with reverse self-locking function according to claim 1, characterized in that: The planetary gear assembly includes pin holes at both ends of the planet carrier (15), with a pin shaft (19) passing through each pin hole. The first planetary gear (9) and the second planetary gear (11) are coaxially sleeved on the pin shaft (19) and arranged axially. The line connecting the axis of the adjacent pin hole and the axis of the planet carrier (15) forms the central angle of the pin hole, and the central angles of the adjacent pin holes are all different.

3. The kingpin steering gear with reverse self-locking function according to claim 2, characterized in that: An elastic bushing (20) is provided in the pin hole, and adjacent elastic bushings (20) are pre-loaded with opposite or opposing pre-tightening forces.

4. The kingpin steering gear with reverse self-locking function according to claim 3, characterized in that: The elastic bushing (20) includes an outer ring (201), an inner ring (202), and an elastic element (203) located between the two. The outer ring (201) is fixed in the pin hole, the inner ring (202) is fixed on the pin (19), and the elastic element (203) provides the preload force.

5. The kingpin steering gear with reverse self-locking function according to claim 1, characterized in that: The teeth of the second planetary gear (11) are arranged in an inverted conical cross section from top to bottom in the tooth width direction; the second gear ring (12) forms a tooth inter-tooth portion with an inverted conical cross section in the tooth width direction.

6. The kingpin steering gear with reverse self-locking function according to claim 1, characterized in that: The speed ratio of the double planetary gear train is greater than 350, and the transmission efficiency is less than 50%.

7. The kingpin steering gear with reverse self-locking function according to claim 1, characterized in that: An angle sensor (18) is provided at the bottom of the reducer housing (2) and is sleeved on the outside of the output shaft (13).

8. The kingpin steering gear with reverse self-locking function according to claim 1, characterized in that: The first gear ring (10) is fixed inside the reducer housing (2), and the second gear ring (12) is fixed to the output shaft (13) to serve as power output.

9. The kingpin steering gear with reverse self-locking function according to claim 1, characterized in that: The bottom end of the output shaft (13) is an output flange (14). The output shaft (13) is connected to the reducer housing (2) by a bearing (16) and a sealed cavity is formed by an oil seal (17).

10. Angle module assembly, characterized in that: The system includes a wheel (200), a hub motor, a steering knuckle (300), and a kingpin steering system (100) as described in any one of claims 1-9 connected to the suspension system. The torque output end of the kingpin steering system (100) is connected to the first end of the steering knuckle (300), and the second end of the steering knuckle (300) is connected to the wheel (200). The kingpin steering system (100) can drive the wheel to turn by driving the steering knuckle (300).

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