Steer-by-wire actuator

Abstract

The utility model discloses a steer-by-wire actuator which comprises a frame assembly, a ball screw assembly which penetrates through the frame assembly and is in sliding connection with the frame assembly, and a driving unit which is fixedly arranged on the frame assembly and is used for driving the ball screw assembly to move relative to the frame assembly. A gear and rack structure of a traditional steering gear is omitted, the overall structure is simpler, the manufacturing cost is low, when the power unit drives the driven wheel to rotate, the driven wheel can drive the ball screw assembly to move in the axial direction relative to the frame assembly under the action of threads, the ball screw assembly does not rotate along with the driving unit under limiting of the linear bearing, and the service life of the ball screw assembly is prolonged. Therefore, the displacement precision of the ball screw assembly is ensured.

Description

Technical Field

[0001] This utility model relates to the field of vehicle component technology, and in particular to a steer-by-wire actuator. Background Technology

[0002] With the development of automotive electronics, intelligence, and humanization, steer-by-wire systems have eliminated the intermediate drive shaft. The steering wheel and steering actuator are connected by electrical signals, and there is no direct mechanical transmission path between the steering mechanism and the driver, resulting in higher safety. The system uses a motor-driven belt with an appropriate reduction ratio to achieve the effect of speed reduction and torque increase, ultimately outputting appropriate rack force to drive the tires to steer.

[0003] Traditional steering mechanisms use a rack and pinion structure, which is prone to noise during operation, has complex parts processing, a large number of parts, and high overall processing costs. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a steer-by-wire actuator that is simple in structure, low in processing cost, and has high transmission accuracy.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution.

[0006] This application provides a steer-by-wire actuator, comprising:

[0007] Frame assembly;

[0008] A ball screw assembly passes through the frame assembly and is slidably connected to the frame assembly;

[0009] The drive unit is fixedly mounted on the frame assembly and is used to drive the ball screw assembly to move relative to the frame assembly.

[0010] The drive unit includes a driven wheel that is rotatably mounted on the frame assembly and coaxial with the ball screw assembly, and a power unit for driving the driven wheel to rotate. The ball screw assembly passes through the driven wheel and is threadedly connected to the driven wheel.

[0011] The frame assembly is fixedly provided with a linear bearing that is slidably connected to the ball screw assembly. The linear bearing is used to limit the circumferential rotation of the ball screw assembly relative to the frame assembly.

[0012] Further specifying, in the above-mentioned steer-by-wire actuator, the power unit includes an assist motor fixedly mounted on the frame assembly, a drive wheel parallel to the central axis of the driven wheel is fixedly mounted on the power output end of the assist motor, and a transmission belt is wound around the drive wheel and the driven wheel;

[0013] The diameter of the driving wheel is smaller than the diameter of the driven wheel.

[0014] Further specifying, in the aforementioned steer-by-wire actuator, the drive unit further includes a rotating bearing disposed between the driven wheel and the frame assembly and coaxial with the driven wheel.

[0015] Further specifying, the aforementioned steer-by-wire actuator also includes a sensing component for monitoring the relative displacement between the ball screw assembly and the frame assembly.

[0016] Further specifying, in the aforementioned steer-by-wire actuator, the sensing component includes a displacement sensor fixedly mounted on the frame assembly and a sensing unit fixedly mounted on the ball screw assembly and capable of cooperating with the displacement sensor.

[0017] Further specifying, in the above-mentioned steer-by-wire actuator, the sensing unit includes a mounting base fixedly mounted on the ball screw assembly, and a first sensing block and a second sensing block are fixedly mounted on the mounting base;

[0018] The displacement sensor is provided with a first induction coil for cooperating with a first induction block and a second induction coil for cooperating with a second induction block, and the first induction coil and the second induction coil extend along the axial direction of the ball screw assembly.

[0019] Further specifying, in the above-mentioned steer-by-wire actuator, the ball screw assembly includes a screw section, a positioning section, and a limiting section that are coaxially and fixedly connected in sequence;

[0020] The lead screw section is threadedly connected to the driven wheel, the positioning section is fixedly equipped with a sensing unit, and the limiting section is slidably connected to the linear bearing.

[0021] Further specifying, in the above-mentioned steer-by-wire actuator, the limiting segment is specifically configured as a non-rotating body, and the linear bearing is provided with a cavity that matches the shape of the limiting segment.

[0022] Further specifying, in the above-mentioned steer-by-wire actuator, the ball screw assembly, sensing unit, and displacement sensor are disposed within the frame assembly;

[0023] The frame assembly has an opening and a detachable sealing cover.

[0024] The displacement sensor is fixedly mounted on the sealing cover plate, and the sealing cover plate can cover the opening on the frame assembly.

[0025] Further specifying, in the above-mentioned steer-by-wire actuator, both ends of the ball screw assembly are respectively fixedly connected to an inner steering tie rod, and the end of the inner steering tie rod away from the ball screw assembly is fixedly connected to an outer steering tie rod;

[0026] And / or, corrugated dust covers are fixedly connected to both ends of the ball screw assembly, and the corrugated dust covers are sleeved on the ball screw assembly and fixedly connected to the frame assembly.

[0027] This utility model has at least the following beneficial effects:

[0028] 1. The traditional steering gear rack structure has been eliminated, making the overall structure simpler and the manufacturing cost lower. When the power unit drives the driven wheel to rotate, the driven wheel can drive the ball screw assembly to move axially relative to the frame assembly under the action of the thread. Under the limit of the linear bearing, the ball screw assembly will not rotate with the drive unit, thus ensuring the displacement accuracy of the ball screw assembly.

[0029] 2. The displacement of the ball screw assembly relative to the frame assembly is monitored by the first sensing block and the first sensing coil, and the second sensing block and the second sensing coil, respectively. Through the dual verification of the sensing unit and the displacement sensor, the displacement control accuracy of the ball screw assembly can be guaranteed, which meets the vehicle's steer-by-wire function.

[0030] 3. The corrugated dust cover ensures the sealing of components along the movement path of the ball screw assembly, preventing dust or other foreign objects from entering and ensuring the overall operational stability of the device. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the steer-by-wire actuator according to an embodiment of this application;

[0032] Figure 2 This is an enlarged structural diagram of the "sensing unit 300" portion in the steer-by-wire actuator of an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the steer-by-wire actuator in an embodiment of this application, with the "frame assembly" omitted.

[0034] Figure 4 This is a schematic diagram showing the assembly of "ball screw assembly 100, sensing unit 300, and linear bearing 500" in the steer-by-wire actuator of this application embodiment;

[0035] Figure 5 This is a schematic diagram of the structure of the "linear bearing 500" in the steer-by-wire actuator of this application embodiment;

[0036] Figure 6 This is a schematic diagram of the structure of the "displacement sensor 900" in the steer-by-wire actuator of this application embodiment.

[0037] Figure Labels

[0038] Ball screw assembly - 100, screw section - 110, positioning section - 120, limit section - 130, drive frame - 210, screw frame - 220, sealing cover plate - 230, sensing unit - 300, mounting base - 310, first sensing block - 320, second sensing block - 330, drive unit - 400, power assist motor - 410, drive wheel - 420, transmission belt - 430, driven wheel - 440, rotary bearing - 450, linear bearing - 500, cavity - 510, corrugated dust cover - 600, inner steering tie rod - 700, outer steering tie rod - 800, displacement sensor - 900, first induction coil - 910, second induction coil - 920. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0040] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0041] The steer-by-wire actuator provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0042] like Figures 1 to 6 As shown, this application provides a steer-by-wire actuator, including a frame assembly, a ball screw assembly 100 that passes through the frame assembly and is slidably connected to the frame assembly, and a drive unit 400 that is fixedly mounted on the frame assembly and is used to drive the ball screw assembly 100 to move relative to the frame assembly.

[0043] The drive unit 400 includes a driven wheel 440 rotatably mounted on the frame assembly and coaxial with the ball screw assembly 100, and a power unit for driving the driven wheel 440 to rotate. The ball screw assembly 100 passes through the driven wheel 440 and is threadedly connected to the driven wheel 440.

[0044] The frame assembly is fixedly provided with a linear bearing 500 that is slidably connected to the ball screw assembly 100. The linear bearing 500 is used to limit the circumferential rotation of the ball screw assembly 100 relative to the frame assembly.

[0045] In this embodiment, the above-mentioned steer-by-wire actuator is used, eliminating the traditional steering gear rack structure, making the overall structure simpler and the manufacturing cost lower. When the power unit drives the driven wheel 440 to rotate, the driven wheel 440 can drive the ball screw assembly 100 to move axially relative to the frame assembly under the action of the thread. Under the limit of the linear bearing 500, the ball screw assembly 100 will not rotate with the drive unit 400, thereby ensuring the displacement accuracy of the ball screw assembly 100.

[0046] In a preferred embodiment, such as Figure 3 As shown, the power unit includes an assist motor 410 fixedly mounted on the frame assembly. An active wheel 420 parallel to the central axis of the driven wheel 440 is fixedly mounted on the power output end of the assist motor 410. A transmission belt 430 is wound around the active wheel 420 and the driven wheel 440.

[0047] The diameter of the driving wheel 420 is smaller than the diameter of the driven wheel 440.

[0048] It is understandable that when the power assist motor 410 drives the drive wheel 420 to rotate, the driven wheel 440 rotates synchronously under the transmission of the transmission belt 430. Since the diameter of the drive wheel 420 is smaller than the diameter of the driven wheel 440, the transmission speed reduction of the driven wheel 440 is achieved, thus ensuring the rotational torque of the driven wheel 440.

[0049] In a preferred embodiment, such as Figure 3 As shown, the drive unit 400 also includes a rotary bearing 450 disposed between the driven wheel 440 and the frame assembly and coaxial with the driven wheel 440.

[0050] Understandably, the rotating bearing 450 can both support and fix the driven wheel 440 on the frame assembly and enable the driven wheel 440 to rotate relative to the frame assembly.

[0051] In a preferred embodiment, such as Figure 3 , Figure 4 As shown, the ball screw assembly 100 includes a screw section 110, a positioning section 120, and a limiting section 130 that are coaxially connected in sequence.

[0052] The lead screw section 110 is threadedly connected to the driven wheel 440, and the limiting section 130 is slidably connected to the linear bearing 500.

[0053] In a preferred embodiment, such as Figures 3 to 5As shown, the limiting segment 130 is specifically configured as a non-rotating body.

[0054] The linear bearing 500 has a cavity 510 that matches the shape of the limiting section 130.

[0055] It is understandable that, since the limiting segment 130 is a non-rotating body and fits the shape of the cavity 510, the limiting segment 130 can only move axially relative to the frame assembly under the limiting of the inner wall of the cavity 510, and its circumferential rotation is restricted, thereby ensuring the linear movement stability of the ball screw assembly 100.

[0056] In a preferred embodiment, such as Figures 1 to 4 , Figure 6 As shown, it also includes a sensing component for monitoring the relative displacement between the ball screw assembly 100 and the frame assembly.

[0057] In a preferred embodiment, such as Figures 1 to 4 , Figure 6 As shown, the sensing component includes a displacement sensor 900 fixedly mounted on the frame assembly and a sensing unit 300 fixedly mounted on the positioning section 120 and capable of cooperating with the displacement sensor 900.

[0058] Understandably, when the ball screw assembly 100 moves relative to the frame assembly, the displacement sensor 900 can record the displacement of the sensing unit 300 relative to the frame assembly, thereby achieving precise control of the movement of the ball screw assembly 100.

[0059] In a preferred embodiment, such as Figures 1 to 4 , Figure 6 As shown, the sensing unit 300 includes a mounting base 310 fixedly mounted on the ball screw assembly 100, and a first sensing block 320 and a second sensing block 330 are fixedly mounted on the mounting base 310.

[0060] The displacement sensor 900 is provided with a first induction coil 910 for cooperating with the first induction block 320 and a second induction coil 920 for cooperating with the second induction block 330. The first induction coil 910 and the second induction coil 920 extend along the axial direction of the ball screw assembly 100.

[0061] In this embodiment, a steer-by-wire actuator as described above is used. The displacement of the ball screw assembly 100 relative to the frame assembly is monitored by the first sensing block 320 and the first sensing coil 910, and the second sensing block 330 and the second sensing coil 920, respectively. Through the dual verification of the sensing unit 300 and the displacement sensor 900, the displacement control accuracy of the ball screw assembly 100 can be guaranteed, thus satisfying the steer-by-wire function of the vehicle.

[0062] It is understandable that the cooperation between the sensing unit 300 and the displacement sensor 900 is not limited to the one mentioned above. For example, the sensing unit 300 and the displacement sensor 900 can be further configured to perform triple verification, as long as the displacement monitoring of the ball screw assembly 100 can be satisfied and the displacement accuracy can be guaranteed. This will not be elaborated here.

[0063] In a preferred embodiment, such as Figure 1 As shown, the frame assembly includes a drive frame 210 and a lead screw frame 220 fixedly connected to the drive frame 210.

[0064] The drive unit 400 is fixedly installed in the drive frame 210, and the ball screw assembly 100, the sensing unit 300, and the displacement sensor 900 are installed in the screw frame 220.

[0065] In a preferred embodiment, such as Figure 1 As shown, the frame assembly also includes a sealing cover plate 230, on which the displacement sensor 900 is fixedly mounted.

[0066] The lead screw frame 220 has an opening, and the sealing cover 230 is detachably connected to the lead screw frame 220 and can cover the opening on the lead screw frame 220.

[0067] Understandably, the displacement sensor 900 inside the lead screw frame 220 can be removed through the sealing cover 230, facilitating the maintenance of the sensing components.

[0068] In a preferred embodiment, such as Figure 1 As shown, the ball screw assembly 100 has an inner steering tie rod 700 fixedly connected to both ends, and an outer steering tie rod 800 fixedly connected to the end of the inner steering tie rod 700 away from the ball screw assembly 100.

[0069] Understandably, the outer steering tie rod 800 is used to connect the vehicle's tires. Through the linear movement of the ball screw assembly 100, the steering of the tires can be controlled by the inner steering tie rod 700 and the outer steering tie rod 800 respectively.

[0070] In a preferred embodiment, such as Figure 1 As shown, corrugated dust covers 600 are fixedly connected to both ends of the ball screw assembly 100. The corrugated dust covers 600 are sleeved on the ball screw assembly 100 and fixedly connected to the frame assembly.

[0071] Understandably, the corrugated dust cover 600 can ensure the sealing of components along the movement path of the ball screw assembly 100, prevent dust or other foreign objects from entering, and ensure the overall working stability of the device.

[0072] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0073] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A steer-by-wire actuator, characterized in that, include: Frame assembly; A ball screw assembly passes through the frame assembly and is slidably connected to the frame assembly; The drive unit is fixedly mounted on the frame assembly and is used to drive the ball screw assembly to move relative to the frame assembly. The drive unit includes a driven wheel that is rotatably mounted on the frame assembly and coaxial with the ball screw assembly, and a power unit for driving the driven wheel to rotate. The ball screw assembly passes through the driven wheel and is threadedly connected to the driven wheel. The frame assembly is fixedly provided with a linear bearing that is slidably connected to the ball screw assembly. The linear bearing is used to limit the circumferential rotation of the ball screw assembly relative to the frame assembly.

2. The steer-by-wire actuator according to claim 1, characterized in that, The power unit includes an assist motor fixedly mounted on the frame assembly. A drive wheel parallel to the central axis of the driven wheel is fixedly mounted on the power output end of the assist motor. A transmission belt is wound around the drive wheel and the driven wheel. The diameter of the driving wheel is smaller than the diameter of the driven wheel.

3. A steer-by-wire actuator according to claim 1 or 2, characterized in that, The drive unit also includes a rotating bearing disposed between the driven wheel and the frame assembly and coaxial with the driven wheel.

4. A steer-by-wire actuator according to claim 1, characterized in that, It also includes a sensing component for monitoring the relative displacement between the ball screw assembly and the frame assembly.

5. A steer-by-wire actuator according to claim 4, characterized in that, The sensing component includes a displacement sensor fixedly mounted on the frame assembly and a sensing unit fixedly mounted on the ball screw assembly and capable of cooperating with the displacement sensor.

6. A steer-by-wire actuator according to claim 5, characterized in that, The sensing unit includes a mounting base fixedly mounted on the ball screw assembly, and a first sensing block and a second sensing block are fixedly mounted on the mounting base. The displacement sensor is provided with a first induction coil for cooperating with a first induction block and a second induction coil for cooperating with a second induction block, and the first induction coil and the second induction coil extend along the axial direction of the ball screw assembly.

7. A steer-by-wire actuator according to claim 1, 5, or 6, characterized in that, The ball screw assembly includes a screw section, a positioning section, and a limiting section that are coaxially and fixedly connected in sequence. The lead screw section is threadedly connected to the driven wheel, the positioning section is fixedly equipped with a sensing unit, and the limiting section is slidably connected to the linear bearing.

8. A steer-by-wire actuator according to claim 7, characterized in that, The limiting segment is specifically configured as a non-rotating body, and the linear bearing has a cavity that matches the shape of the limiting segment.

9. A steer-by-wire actuator according to claim 5, characterized in that, The ball screw assembly, sensing unit, and displacement sensor are housed within the frame assembly. The frame assembly has an opening and a detachable sealing cover. The displacement sensor is fixedly mounted on the sealing cover plate, and the sealing cover plate can cover the opening on the frame assembly.

10. A steer-by-wire actuator according to claim 1, characterized in that, The ball screw assembly is fixedly connected to two ends of an inner steering tie rod, and the inner steering tie rod is fixedly connected to an outer steering tie rod at the end away from the ball screw assembly. And / or, corrugated dust covers are fixedly connected to both ends of the ball screw assembly, and the corrugated dust covers are sleeved on the ball screw assembly and fixedly connected to the frame assembly.

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