Servo unit, steering engine and vehicle

Abstract

The utility model provides a servo unit, a steering engine and a vehicle. The servo unit (100) is used for a steering machine of a vehicle, the servo unit (100) comprises a steering control unit (1) and a steering transmission unit (2), the steering control unit (1) comprises a motor (11) and a connecting assembly (12) fixedly arranged on a motor shaft (111) of the motor (11) in a sleeving mode, the steering transmission unit (2) comprises a shell (21), the shell (21) forms a containing space (211), and the containing space (211) is arranged in the shell (21). The connecting assembly (12) is arranged in the containing space (211), the servo unit (100) further comprises a sealing piece (3), and the sealing piece (3) is arranged between the connecting assembly (12) and the inner wall of the shell (21) in a sealing and sleeving mode in the radial direction. The present disclosure prevents oil in the housing of the steering transmission unit from entering the motor of the steering control unit in a cost-effective manner.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle steering, and more specifically, to a servo unit, a steering gear, and a vehicle. Background Technology

[0002] This section aims to provide background information relevant to understanding the various techniques described herein. As the title of this section implies, this is a discussion of related techniques that should in no way imply that they are necessarily prior art. Therefore, it should be understood that any statement in this section should be read in this context, rather than as an admission of any prior art.

[0003] In some vehicle models, the steering gear housing is not open, preventing hydraulic fluid from entering the servo unit, resulting in no seal between the steering control unit and the steering transmission unit housing. Utility Model Content

[0004] Depending on the specifics, the purpose of this disclosure is to prevent oil from entering the motor of the steering control unit in a cost-effective manner.

[0005] Furthermore, the purpose of this disclosure is to solve or at least alleviate one or more problems existing in the prior art.

[0006] This disclosure addresses the aforementioned problems by providing a servo unit, a steering gear, and a vehicle. Specifically, according to one aspect of this disclosure, the following is provided:

[0007] A servo unit for a vehicle steering gear, wherein the servo unit includes a steering control unit and a steering transmission unit, the steering control unit includes a motor and a connecting assembly fixedly sleeved on the motor shaft, the steering transmission unit includes a housing forming a receiving space, the connecting assembly being arranged within the receiving space, and the servo unit further includes a seal, the seal being radially and sealingly sleeved between the connecting assembly and the inner wall of the housing.

[0008] Optionally, according to one embodiment of this disclosure, the steering transmission unit includes a worm gear, the connecting assembly includes a first connector, a second connector, and a sleeve, the first connector is fixedly sleeved on the end of the motor shaft, the second connector is fixedly sleeved on the end of the worm gear, the sleeve is fixedly sleeved on the first connector and the second connector, and the sealing member is radially sealed between the first connector and the inner wall of the housing.

[0009] Optionally, according to one embodiment of the present disclosure, the first connector includes a first body and a first flange connected to each other, the first body engaging with the sleeve, the first flange being sealed to the inner wall of the housing by the sealing member, the first flange having a receiving portion, and the end of the motor shaft extending into the receiving portion and engaging with the receiving portion.

[0010] Optionally, according to one embodiment of the present disclosure, the steering transmission unit includes a swing bearing, which is radially sleeved between the end of the worm gear and the inner wall of the housing, and the second connecting member is axially disposed between the first connecting member and the swing bearing, and the sleeve is configured as a thermoplastic elastomer.

[0011] Optionally, according to one embodiment of this disclosure, the first connector is made of powder metallurgy material or steel.

[0012] Optionally, according to one embodiment of this disclosure, when the first connector is made of powder metallurgy material, the density of the first connector is configured to be greater than 7.0 g / cm³. 3 The surface hardness of the first connector is configured to be greater than 45 HRC.

[0013] Optionally, according to one embodiment of the present disclosure, the end face of the first body facing the second connector has a first chamfer, and the end face of the first flange facing the second connector has a second chamfer.

[0014] Optionally, according to one embodiment of the present disclosure, the second connector includes a second body and a second flange connected to each other, the sleeve is radially sleeved and engaged with the first body and the second body, the axial length of the second flange is 1 mm to 3 mm, the axial length of the first flange is 8 mm to 12 mm, and the outer end face of the seal extends axially into the receiving space by a distance of 5 mm to 7 mm.

[0015] According to another aspect of this disclosure, a steering mechanism for a vehicle is provided, wherein the steering mechanism includes any of the aforementioned servo units.

[0016] According to another aspect of this disclosure, a vehicle is provided, wherein the vehicle includes the aforementioned steering mechanism. Attached Figure Description

[0017] Referring to the accompanying drawings, the above and other features of this disclosure will become apparent, wherein,

[0018] Figure 1 A partial perspective view of the internal structure of a steering gear according to the present disclosure is shown;

[0019] Figure 2A cross-sectional view showing the cooperation relationship between a steering control unit and a steering transmission unit according to the present disclosure is shown; and

[0020] Figure 3 A perspective view of a first connector according to the present disclosure is shown. Detailed Implementation

[0021] It is readily understood that, based on the technical solutions of this disclosure, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this disclosure. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solutions of this disclosure and should not be considered as the entirety of this disclosure or as limitations or restrictions on the technical solutions of this disclosure.

[0022] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive. Furthermore, the terms "first," "second," "third," and similar expressions are used for descriptive and distinguishing purposes only and should not be construed as indicating or implying the relative importance of the corresponding components.

[0023] Figure 1 A partial perspective view of the internal structure of a steering gear according to the present disclosure is shown; and Figure 2 A cross-sectional view showing the cooperation relationship between a steering control unit and a steering transmission unit according to the present disclosure is shown.

[0024] This disclosure relates to a servo unit 100 for a vehicle steering gear, wherein the servo unit 100 includes a steering control unit 1 and a steering transmission unit 2. The steering control unit 1 includes a motor 11 and a connecting assembly 12 fixedly sleeved on a motor shaft 111 of the motor 11. The steering transmission unit 2 includes a housing 21 forming a receiving space 211. The connecting assembly 12 is arranged within the receiving space 211. The servo unit 100 also includes a seal 3, which is radially sealed between the connecting assembly 12 and the inner wall of the housing 21.

[0025] It should be understood that a vehicle's steering gear provides steering assistance, amplifying the force generated when the driver turns the steering wheel according to the driver's intention and changing the direction of this force transmission. Through an internal mechanical structure, the steering force is transmitted to the wheels, enabling them to effectively drive the wheels to steer. For this purpose, the steering gear, exemplarily, includes: an Electronic Control Unit (ECU), used to collect signals from various sensors (e.g., vehicle speed, steering angle), determine the vehicle's steering state (e.g., power assist or return to center), calculate the required steering assistance magnitude and direction, and send control commands to the steering control unit; a motor of the steering control unit receiving the control commands from the ECU and generating the required assist torque according to the assist characteristics; and a steering transmission unit, connected to the steering control unit, for example, a worm gear transmission structure where the motor of the steering control unit transmits power to the worm via a motor shaft, the worm transfers power to the worm wheel 24, and the worm wheel outputs power to other components of the steering gear (e.g., another worm, piston, drop arm, etc.), ultimately transmitting it to the wheels.

[0026] As described in the background section, in some embodiments, the steering gear housing is not perforated, preventing hydraulic fluid from entering the servo unit, thus there is no seal between the housings of the steering control unit and the steering transmission unit. However, for reasons such as reducing the number of overall components and the overall weight, or due to housing damage, the housing is perforated. This poses a risk of hydraulic fluid entering the servo unit. For example, if the perforated area of ​​the housing is located in the worm gear area of ​​the steering transmission unit, hydraulic fluid may enter the housing cavity containing the worm gear of the servo unit from the steering gear's inlet, and then flow to the cavity area containing the worm, thus posing a risk of intrusion into the motor area. Therefore, sealing measures are needed to address the above situation.

[0027] According to the seal disclosed herein, external impurities such as oil effectively prevent the intrusion of internal components into the motor, thereby protecting internal parts, extending service life, and improving the reliability of the steering gear. Furthermore, the fixed connection between the connecting assembly and the motor shaft ensures the stability and reliability of power transmission, providing an effective foundation for power transmission between the connecting assembly and subsequent components. The housing of the steering transmission unit forms a receiving space, in which the connecting assembly (the output end of the motor shaft can also be located) is arranged. This design makes the servo unit structure more compact, improves space utilization, and facilitates overall installation and maintenance. The seal not only provides a sealing function but also reduces friction between the connecting assembly and the inner wall of the housing to a certain extent, reducing operating noise and wear, and improving the operating efficiency of the steering gear.

[0028] Depending on the specific arrangement and function of the seal, it can be referred to as a shaft seal in some cases. It is feasible to construct the seal as a rubber ring (such as fluororubber and DISCOD), which can tightly fit the contact surface under pressure to form a reliable seal. It has a wide operating temperature range, is suitable for dynamic sealing, has low frictional resistance, and controllable installation and maintenance costs. Therefore, in this technical solution, the seal is fitted between the connecting component and the inner wall of the housing, achieving a stable and reliable sealing effect. To improve the sealing effect, those skilled in the art can also use multiple sealing rings.

[0029] The steering transmission unit 2 includes a worm gear 22, and the connecting assembly 12 includes a first connecting member 121, a second connecting member 122, and a sleeve 123. The first connecting member 121 is fixedly sleeved on the end of the motor shaft 111, the second connecting member 122 is fixedly sleeved on the end of the worm gear 22, and the sleeve 123 is fixedly sleeved on the first connecting member 121 and the second connecting member 122. The sealing member 3 is radially sealed between the first connecting member 121 and the inner wall of the housing 21.

[0030] This technical solution primarily refines the design of the connecting components and discloses that the steering transmission unit can be based on worm gear transmission. It is understood that the fixed arrangement of the sleeve, the first connecting member, and the second connecting member enhances the overall structural stability of the connecting components, making the power transmission between the motor shaft and the worm gear more reliable. Simultaneously, the split design simplifies maintenance procedures and reduces costs. Therefore, a seal is placed between the first connecting member and the inner wall of the housing, maintaining the original technical effect while providing more targeted sealing for the motor, particularly maintaining a more stable dynamic sealing effect. Depending on different requirements, a seal can also be placed between the sleeve or the second connecting member and the inner wall of the housing.

[0031] Figure 3 A perspective view of a first connector according to the present disclosure is shown.

[0032] The first connector 121 includes a first body 1211 and a first flange 1212 connected to each other. The first body 1211 engages with the sleeve 123. The first flange 1212 is sealed to the inner wall of the housing 21 by the sealing member 3. The first flange 1212 has a receiving portion 12121. The end of the motor shaft 111 extends into the receiving portion 12121 and engages with the receiving portion 12121.

[0033] It should be understood that the outer diameter of the first flange is larger than the outer diameter of the first body. Therefore, this technical solution specifically differentiates the structure of the first connector, with the first body primarily used for mating with the sleeve, and the first flange primarily used for mating with the seal and motor shaft. This allows for a more targeted design of the first connector. The second connector, including its mating with the sleeve, can also be designed similarly.

[0034] Among them, the meshing connection can provide a strong mechanical connection force, ensuring a stable connection between the first connecting piece and the sleeve, as well as between the motor shaft and the first connecting piece, thereby enhancing the structural strength and stability of the entire connection assembly connection area. This allows the overall rotational motion of the motor to be transmitted to the worm gear more accurately, improving the transmission accuracy and controllability, and also facilitating subsequent maintenance work.

[0035] Regarding the specific meshing method, an example is that it can be achieved through toothed meshing. For instance, the outer peripheral surface of the first body has several protrusions 12112 evenly distributed circumferentially to form a toothed structure, and the inner peripheral surface of the sleeve has correspondingly several recesses. Meshing is achieved through the engagement of the protrusions and recesses. Similarly, the meshing of the receiving portion of the first flange with the motor shaft, and the optional second connector with the sleeve, can also be constructed in this way. Alternatively, a spline fit can also be used for motion transmission.

[0036] from Figure 2 It can also be clearly seen that the steering transmission unit 2 includes a swing bearing 23, which is radially sleeved between the end of the worm gear 22 and the inner wall of the housing 21. The second connecting member 122 is axially disposed between the first connecting member 121 and the swing bearing 23. The sleeve 123 is constructed as a thermoplastic elastomer.

[0037] The oscillating bearing ensures the correct positioning of the worm gear during rotation, reduces friction between the worm and the housing, lowers wear, and improves the durability and reliability of the steering transmission unit. In actual operation, the steering gear may be adjusted via the oscillating bearing. Specifically, the worm and turbine are connected via gears, and prolonged operation can cause wear on the gear teeth, resulting in a gap between the two gears. The oscillation of the oscillating bearing is used to adjust the gap between these two gears, reducing the gap and achieving a tight fit. Considering that the oscillating bearing is assembled, for example, by press-fit (interference fit) onto the worm, the worm connected to it will also undergo radial displacement (radial runout) as the oscillating bearing oscillates. This could lead to significant radial clearance runout at the oscillating bearing, the end of the screw, or the area of ​​the second connecting piece. To address this risk and ensure a good seal, this technical solution uses a thermoplastic elastomer sleeve, which possesses good elasticity, toughness, wear resistance, and corrosion resistance, and contributes to weight reduction. This material is used to absorb any runout that may occur at the left end, ensuring stable motion transmission from the motor to the worm. It is also evident that if a seal is installed on the worm, the large radial runout (large displacement) of the worm will affect the function of the seal and may lead to oil leakage. Therefore, in this disclosure, the seal fitted on the first connecting member can stably perform the sealing function.

[0038] To provide sufficient space for the seal, it is feasible to design the axial dimension of the first flange of the first connector to be relatively long, for example, longer than the axial dimension of the corresponding flange of the second connector. For this purpose, the first connector 121 can be made of steel to ensure sufficient density and hardness, thereby providing strong support for the seal during operation and ensuring the seal performs its function effectively. Besides steel, materials such as ceramics, hard alloys, metallic glass, polymers, and aluminum alloys can also be considered.

[0039] In some other embodiments, considering factors such as cost, the first connector 121 can also be made of powder metallurgy material. It should be understood that powder metallurgy material refers to porous, semi-dense, or fully dense materials (including products) produced using powder metallurgy processes. Powder metallurgy is a process technology that uses metal powder (or a mixture of metal and non-metal powders) as raw materials, for example, through forming and sintering, to manufacture metal materials, composite materials, and various types of products. This process generates almost no waste, thus significantly improving material utilization. Compared to traditional processing methods, it can significantly save raw materials and achieve high-precision manufacturing of parts with complex shapes. Those skilled in the art can select the most suitable material combination and process parameters according to actual needs for component design. Specifically, powder metallurgy materials can be, for example, materials composed of iron, copper, and carbon; of course, other materials or impurities may be permitted if necessary.

[0040] To further ensure the sealing capability of the seal, in some embodiments of this disclosure, when the first connector 121 is made of powder metallurgy material, the density of the first connector 121 is configured to be greater than 7.0 g / cm³. 3 The surface hardness of the first connector 121 is configured to be greater than 45 HRC.

[0041] Among them, when the density of powder metallurgy material is greater than 7.0 g / cm³ 3 At this stage, the effective load-bearing area of ​​the material increases, resulting in better density and uniformity. The alloying effect is fully realized, significantly improving the strength and hardness of the connector and reducing the risk of stress concentration and crack propagation. Connectors with a surface hardness greater than 45 HRC exhibit excellent wear resistance, maintaining a long service life under frictional wear conditions. The resulting high-density, high-hardness primary connector provides more stable and reliable connection performance, optimizes the overall system's operating efficiency, and its longer service life and lower failure rate also reduce maintenance costs.

[0042] Those skilled in the art will understand that desired density or hardness can be achieved in various ways during the manufacturing process. For example, during the manufacturing of the first connector, its density is increased by adding resin sealing and external surface extrusion processes, and its surface hardness is increased by separate heat treatment. The resin sealing process involves forming a resin seal layer on the connector surface to fill the tiny pores and defects. This resin seal layer not only reduces porosity and improves the density of the connector but also enhances the smoothness and flatness of the connector surface. In the external surface extrusion process, extruding the external surface further compacts the material inside the connector, reducing internal pores and defects, thereby increasing the density and overall strength of the connector, making it more robust and durable. During heat treatment, the internal crystal structure of the material changes, forming a denser and harder surface layer, thereby improving the wear resistance and scratch resistance of the connector. In addition, although not elaborated in detail in this disclosure, those skilled in the art may also use methods such as hot isostatic pressing, carburizing and nitriding, surface coating, hard anodizing, and superhard coating to improve the density or surface hardness of the first connector. Specific quantitative indicators can also be flexibly adjusted according to actual requirements.

[0043] Regarding the dimensional design, again as an example only, in some embodiments of this disclosure, the second connector 122 includes a second body 1221 and a second flange 1222 connected to each other, the sleeve 123 is radially sleeved and engaged with the first body 1211 and the second body 1221, the axial length of the second flange 1222 is 1 mm to 3 mm, the axial length of the first flange 1212 is 8 mm to 12 mm, and the outer end face of the seal 3 extends axially into the receiving space 211 by a distance of 5 mm to 7 mm.

[0044] According to this technical solution, similar to the first connector, the differentiated design of the second connector allows for better construction for engagement with the sleeve. The shorter axial length of the second flange maintains sufficient structural strength while preserving compactness, facilitating weight reduction. The longer axial length of the first flange facilitates the arrangement of the seal, providing greater compression space and more stable support to fully exert the sealing effect. The axial extension distance design allows the seal to be positioned closer to the end of the motor shaft, providing strong targeting for the motor's oil sealing. As mentioned earlier, these dimensions can be flexibly adjusted according to actual requirements or application conditions.

[0045] from Figure 3 It can also be seen that the end face of the first main body 1211 facing the second connector 122 has a first chamfer 12111, and the end face of the first flange 1212 facing the second connector 122 has a second chamfer 12122. This design is to facilitate the smooth assembly of the first connector into the sleeve via the seal. Specifically, during assembly, the seal is first pressed into the housing's receiving space, and then the pre-assembled motor and first connector assembly is pressed into the housing's receiving space. During this process, the first connector passes through the inside of the seal, which may pose a risk of scratching the seal. The chamfer design, which forms an obtuse angle with the assembly direction, avoids applying excessive force to the seal, thus preventing damage or deformation of the parts. In addition, the chamfer design can also guide the assembly direction.

[0046] According to other aspects of this disclosure, this disclosure also relates to a steering mechanism for a vehicle, wherein the steering mechanism includes any of the aforementioned servo units 100; and to a vehicle, wherein the vehicle includes the aforementioned steering mechanism.

[0047] Therefore, the steering gear and vehicle disclosed herein can inherit various embodiments and corresponding technical effects of the servo unit disclosed herein, which will not be elaborated further here. It is understood that the vehicle may include gasoline vehicles, diesel vehicles, passenger cars, trucks, buses, hybrid vehicles, pure electric vehicles, etc., and can cover light commercial vehicles and heavy commercial vehicles.

[0048] It should be understood that all the above preferred embodiments are exemplary and not restrictive, and various modifications or variations made by those skilled in the art to the specific embodiments described above under the concept of this disclosure should be within the legal protection scope of this disclosure.

Claims

1. A servo unit (100) for a steering gear in a vehicle, characterized in that, The servo unit (100) includes a steering control unit (1) and a steering transmission unit (2). The steering control unit (1) includes a motor (11) and a connecting assembly (12) fixedly sleeved on the motor shaft (111) of the motor (11). The steering transmission unit (2) includes a housing (21) forming a receiving space (211). The connecting assembly (12) is arranged in the receiving space (211). The servo unit (100) also includes a seal (3), which is radially sealed between the connecting assembly (12) and the inner wall of the housing (21).

2. The servo unit (100) according to claim 1, characterized in that, The steering transmission unit (2) includes a worm gear (22), and the connecting assembly (12) includes a first connector (121), a second connector (122), and a sleeve (123). The first connector (121) is fixedly sleeved on the end of the motor shaft (111), the second connector (122) is fixedly sleeved on the end of the worm gear (22), and the sleeve (123) is fixedly sleeved on the first connector (121) and the second connector (122). The sealing member (3) is radially sealed between the first connector (121) and the inner wall of the housing (21).

3. The servo unit (100) according to claim 2, characterized in that, The first connector (121) includes a first body (1211) and a first flange (1212) connected to each other. The first body (1211) engages with the sleeve (123). The first flange (1212) is sealed to the inner wall of the housing (21) by the sealing member (3). The first flange (1212) has a receiving portion (12121). The end of the motor shaft (111) extends into the receiving portion (12121) and engages with the receiving portion (12121).

4. The servo unit (100) according to claim 2, characterized in that, The steering transmission unit (2) includes a swing bearing (23), which is radially sleeved between the end of the worm (22) and the inner wall of the housing (21). The second connecting member (122) is axially disposed between the first connecting member (121) and the swing bearing (23). The sleeve (123) is constructed as a thermoplastic elastomer.

5. The servo unit (100) according to claim 2, characterized in that, The first connector (121) is made of powder metallurgy material or steel.

6. The servo unit (100) according to claim 5, characterized in that, When the first connector (121) is made of powder metallurgy material, the density of the first connector (121) is configured to be greater than 7.0 g / cm³. 3 The surface hardness of the first connector (121) is configured to be greater than 45 HRC.

7. The servo unit (100) according to claim 3, characterized in that, The end face of the first body (1211) facing the second connector (122) has a first chamfer (12111), and the end face of the first flange (1212) facing the second connector (122) has a second chamfer (12122).

8. The servo unit (100) according to claim 3, characterized in that, The second connector (122) includes a second body (1221) and a second flange (1222) connected to each other. The sleeve (123) is radially sleeved and engaged with the first body (1211) and the second body (1221). The axial length of the second flange (1222) is 1 mm to 3 mm, the axial length of the first flange (1212) is 8 mm to 12 mm, and the outer end face of the seal (3) extends axially into the receiving space (211) by a distance of 5 mm to 7 mm.

9. A steering gear for a vehicle, characterized in that, The steering gear includes a servo unit (100) according to any one of claims 1 to 8.

10. A vehicle, characterized in that, The vehicle includes a steering gear as claimed in claim 9.

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