A P-EPS structure for unmanned delivery vehicles

Abstract

This utility model relates to the field of electric power steering technology and discloses a P-EPS structure for unmanned delivery vehicles. It includes an electric steering assembly, which further includes a power steering housing assembly and a main housing assembly. The main housing assembly can be replaced by replacement components to adapt to a C-EPS steering system. The power steering housing assembly includes a spindle assembly, an intermediate housing assembly, a worm gear assembly, a sensor housing assembly, and a sensor wiring harness assembly. This P-EPS structure for unmanned delivery vehicles uses a universal structure with a unified intermediate housing and sensor housing, allowing for multi-platform deployment as a C-EPS system compatible with mechanical steering gears. This meets manufacturers' low-cost requirements. By integrating the steering wheel input shaft, power steering gear shaft, torque angle sensor, and worm gear pair into a single unit, it offers advantages such as compact structure, improved space utilization, and high power assistance.

Description

Technical Field

[0001] This utility model relates to the field of electric power steering technology, specifically a P-EPS structure for unmanned delivery vehicles. Background Technology

[0002] With the growing growth of China's unmanned delivery industry, the demand for autonomous driving is also increasing. Unmanned delivery vehicles have small bodies, and due to their small size, high load capacity, and compact structure, R-EPS and DP-EPS steering assist are sufficient. However, their large size and limited space make them unsuitable for heavy-duty use. The small C-EPS has low reliability, high failure rate, and low torque, making it unsuitable for heavy-duty use. The demand for heavy loads means that the P-EPS steering system structure is the most suitable for its chassis layout.

[0003] Currently, most P-EPS electric power steering systems for autonomous driving have separate mechanical, motor, and controller components, with a single integrated housing. Traditional brushed controllers have low space utilization, require an additional ECU controller, and need protective measures. Furthermore, traditional P-EPS structures are limited, with a single mold only capable of producing a single product, resulting in poor versatility and an inability to meet the needs of multi-platform deployment. Therefore, there is an urgent need for a P-EPS structure for autonomous delivery vehicles to solve these problems. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this utility model provides a P-EPS structure for unmanned delivery vehicles, which has the advantages of compact structure and strong applicability. It solves the problems of R-EPS and DP-EPS, which provide sufficient assistance but are large in size and have limited space; small C-EPS, which has low reliability, high failure rate and low torque, making it unsuitable for heavy-duty use; and traditional P-EPS, which has a single structure and can only produce a single product with one mold, thus having poor applicability.

[0006] (II) Technical Solution

[0007] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A P-EPS structure for unmanned delivery vehicles includes an electric steering assembly, the electric steering assembly further includes a power steering housing assembly and a main housing assembly, the main housing assembly can be replaced by a replacement component to adapt to the C-EPS steering system, the power steering housing assembly includes a spindle assembly, an intermediate housing assembly, a worm gear assembly, a sensor housing assembly and a sensor wiring harness assembly;

[0008] The intermediate housing assembly is fixedly installed on the top of the main housing assembly, the sensor housing assembly is fixedly installed on the top of the intermediate housing assembly, the spindle assembly is assembled inside the intermediate housing assembly, the worm gear assembly is assembled inside the intermediate housing assembly, and the sensor wiring harness assembly is assembled on the side wall of the intermediate housing assembly.

[0009] The spindle assembly includes a gear shaft that extends into and is rotatably connected to the main housing assembly. An input shaft is mounted inside the gear shaft, a rotor mounting cover is mounted outside the gear shaft, a Hella sensor rotor is mounted outside the rotor mounting cover, a Hella sensor assembly is mounted outside the input shaft, and a worm gear is mounted outside the gear shaft.

[0010] The sensor housing assembly includes a sensor housing mounted on top of the intermediate housing assembly, a deep groove ball bearing and an oil seal are installed inside the sensor housing;

[0011] The replacement components include the lower housing assembly and the splined shaft.

[0012] The beneficial effects of this utility model are:

[0013] The P-EPS structure used in unmanned delivery vehicles uses a universal structure with a unified intermediate housing and sensor housing, which allows the product to be deployed on multiple platforms, made into C-EPS, and adapted to mechanical steering gears, thus meeting the low-cost requirements of manufacturers.

[0014] The P-EPS structure used in unmanned delivery vehicles utilizes a rack and pinion transmission. By integrating the steering wheel input shaft, power assist gear shaft, torque angle sensor, and worm gear pair into a single unit, it boasts advantages such as compact structure, improved space utilization, and strong power assistance.

[0015] Based on the above technical solution, the present invention can be further improved as follows.

[0016] Furthermore, the lower housing assembly replaces the main housing assembly and is installed at the bottom of the intermediate housing assembly, and the splined shaft replaces the gear shaft and is connected to the input shaft.

[0017] The advantage of adopting the above-mentioned further solution is that this installation method can realize the transformation from P-EPS to C-EPS.

[0018] Furthermore, the spindle assembly also includes a torsion bar assembled inside the input shaft, the torsion bar having a cylindrical pin assembled inside, and a sliding bearing being provided at the connection between the input shaft and the gear shaft.

[0019] The beneficial effect of adopting the above-mentioned further solution is that a torsion bar and a sliding bearing are press-fitted into the gear shaft, the inner hole of the input shaft head and the outer circle of the torsion bar head are fitted, the outer circle of the input shaft tail and the inner hole of the sliding bearing are fitted, and at the same time, a cylindrical pin is driven into the spline of the input shaft and the torsion bar to achieve the form of fixing the input shaft relative to the torsion bar.

[0020] Furthermore, a brushless motor PPK assembly is fixedly mounted on the side wall of the intermediate housing assembly, and the end of the sensor harness assembly away from the intermediate housing assembly is connected to the brushless motor PPK assembly. The sensor harness assembly is signal-connected to the Hella sensor assembly, and a sealing plug is provided at the connection between the sensor harness assembly and the intermediate housing assembly.

[0021] The advantage of adopting the above-mentioned further solution is that, compared with a brushed motor, the ECU can be integrated into the brushless motor, resulting in a more integrated overall structure.

[0022] Furthermore, the worm gear assembly includes a worm gear mounted on the output shaft of the brushless motor PPK assembly, and the worm gear is connected to the brushless motor PPK assembly via a coupling.

[0023] The beneficial effect of adopting the above-mentioned further solution is that the worm gear is press-fitted onto the spindle assembly to achieve speed reduction and torque increase, converting the motor torque into 20 times the gear torque.

[0024] Furthermore, a rack support seat is installed inside the main housing assembly, and a rack that meshes with the gear shaft is installed inside the main housing assembly.

[0025] The beneficial effect of adopting the above-mentioned further solution is that it adjusts the meshing clearance between the gear shaft and the rack, preventing excessive looseness and abnormal noise.

[0026] Furthermore, an inner tie rod is fitted at one end of the rack extending to the outside of the main housing assembly, and an outer tie rod is fitted at the end of the inner tie rod away from the rack. A protective cover is fitted at one end of the rack located outside the main housing assembly. A single-ear stepless clamp is provided at the connection between the protective cover and the main housing assembly, and a steel band elastic clamp is provided at the connection between the protective cover and the inner tie rod.

[0027] The beneficial effect of adopting the above-mentioned further solution is that a seal is formed between the rack guard and the main housing assembly and the tie rod.

[0028] Furthermore, the main housing assembly has three mounting holes on its side wall, and the mounting surface of the main housing assembly is a flat surface with an annular sealing groove.

[0029] The advantage of adopting the above-mentioned further solution is that three threaded holes are used for locking, and this fit design makes it suitable for different chassis architectures.

[0030] Furthermore, a dust cover is fitted on the top of the sensor housing assembly.

[0031] The advantage of adopting the above-mentioned further solution is that a seal is formed between the sensor housing and the input shaft. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the electric steering gear assembly structure of this utility model;

[0033] Figure 2 This is a cross-sectional view of the electric steering system assembly of this utility model;

[0034] Figure 3 This is a top view of the electric steering gear assembly structure of this utility model;

[0035] Figure 4 This is a schematic diagram of the main housing assembly structure of this utility model;

[0036] Figure 5 This is a schematic diagram of the power steering housing assembly structure of this utility model;

[0037] Figure 6 This is a cross-sectional view of the power steering housing assembly structure of this utility model;

[0038] Figure 7 This is a cross-sectional view of the mandrel assembly structure of this utility model;

[0039] Figure 8 This is a schematic diagram of the replacement component structure of this utility model;

[0040] Figure 9 This is a schematic diagram of the spline shaft structure of this utility model;

[0041] Figure 10 This is a schematic diagram of the lower shell structure of this utility model;

[0042] Figure 11 This is a cross-sectional view of the lower shell structure of this utility model;

[0043] Figure 12 This is a schematic diagram of the sensor housing assembly of this utility model;

[0044] Figure 13 This is a flowchart illustrating the structure of this utility model.

[0045] In the diagram: 1. Electric steering gear assembly; 2. Spindle assembly; 21. Gear shaft; 22. Input shaft; 23. Torsion bar; 24. Cylindrical pin; 25. Rotor mounting cover; 26. Hella sensor rotor; 27. Hella sensor assembly; 28. Worm gear; 3. Intermediate housing assembly; 4. Worm gear assembly; 41. Worm gear; 5. Sensor housing assembly; 51. Sensor housing; 52. Deep groove ball bearing; 53. Oil seal; 6. Sensor wiring harness assembly; 7. Main housing assembly; 8. Lower housing assembly; 81. Splined shaft; 9. Brushless motor PPK assembly; 10. Mounting hole; 11. Rack; 12. Rack support; 13. Inner tie rod; 14. Outer tie rod; 15. Protective cover; 16. Dust cover. Detailed Implementation

[0046] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0047] In the embodiments, by Figure 1-13 Provided is a P-EPS structure for an unmanned delivery vehicle, including an electric steering assembly 1, the electric steering assembly 1 further including a power steering housing assembly and a main housing assembly 7, the main housing assembly 7 can be replaced by a replacement component to adapt to a C-EPS steering system, the power steering housing assembly includes a spindle assembly 2, an intermediate housing assembly 3, a worm gear assembly 4, a sensor housing assembly 5, and a sensor wiring harness assembly 6;

[0048] The intermediate housing assembly 3 is fixedly installed on the top of the main housing assembly 7, the sensor housing assembly 5 is fixedly installed on the top of the intermediate housing assembly 3, the spindle assembly 2 is assembled inside the intermediate housing assembly 3, the worm gear assembly 4 is assembled inside the intermediate housing assembly 3, and the sensor wiring harness assembly 6 is assembled on the side wall of the intermediate housing assembly 3.

[0049] The spindle assembly 2 includes a gear shaft 21 that extends into and is rotatably connected to the main housing assembly 7. An input shaft 22 is mounted inside the gear shaft 21. A rotor mounting cover 25 is mounted outside the gear shaft 21. A Hella sensor rotor 26 is mounted outside the rotor mounting cover 25. A Hella sensor assembly 27 is mounted outside the input shaft 22. A worm gear 28 is mounted outside the gear shaft 21.

[0050] The sensor housing assembly 5 includes a sensor housing 51 mounted on the top of the intermediate housing assembly 3. A deep groove ball bearing 52 is installed inside the sensor housing 51, and an oil seal 53 is installed inside the sensor housing 51.

[0051] A limit plug is provided inside the intermediate housing assembly 3, and the Hella sensor gear housing is fixed inside the limit plug of the intermediate housing.

[0052] The input shaft 22 is internally fitted with a torsion bar 23, and the torsion bar 23 is internally fitted with a cylindrical pin 24. A sliding bearing is provided at the connection between the input shaft 22 and the gear shaft 21.

[0053] The input shaft 22 has a reserved external spline for the steering column, which can match the corresponding steering wheel input to realize manual + automatic driving dual-mode operation. The gear shaft 21 has a torsion bar 23 and a sliding bearing pressed into it. The sliding bearing is located in the sensor housing. The inner hole of the head of the input shaft 22 and the outer circle of the head of the torsion bar are fitted together. The outer circle of the tail of the input shaft 22 is fitted with the inner hole of the sliding bearing. At the same time, the cylindrical pin 24 is driven into the spline of the input shaft 22 and the torsion bar 23 to realize the fixed form of the input shaft 22 relative to the torsion bar 23.

[0054] Specifically, refer to Figure 8 The replacement components include a lower housing assembly 8 and a splined shaft 81. The lower housing assembly 8 replaces the main housing assembly 7 and is installed at the bottom of the intermediate housing assembly 3. The splined shaft 81 replaces the gear shaft 21 and is connected to the input shaft 22. This installation method can realize the conversion from P-EPS to C-EPS.

[0055] Reference Figure 11 As shown, an O-ring bushing is provided on the top of the lower housing assembly 8, and an oil seal 53 is provided on the bottom of the lower housing assembly 8. The splined shaft 81 is connected to the input shaft 22 through its splined part. The end of the splined shaft 81 is designed with a gear structure that meshes with the rack 11, thereby achieving the purpose of directly driving the rack 11. The power steering motor is directly mounted on the steering column of the steering wheel. The transmission structure between the power steering motor and the steering column of the steering wheel is common knowledge, so it will not be described in detail. By directly assisting the steering column through the power steering motor, complex transmission components such as worm gears and worm shafts are omitted, simplifying the transmission path and reducing the complexity and cost of the system. The direct drive method can quickly respond to the driver's steering operation, improve driving comfort and safety, and achieve the commonality of parts.

[0056] When the input shaft 22 is connected to the steering wheel, the input shaft 22 and the torsion bar 23 are fixed together by the cylindrical pin 24, and the lower end of the torsion bar 23 is pressed into the gear shaft 21 for fixation. The torsion bar 23 itself will generate a certain torsion angle. The magnitude of this torsion angle is the magnitude of the steering wheel force on the input shaft 22. The torsion bar 23 and the input shaft 22 are integrated, and the input shaft 22 and the gear shaft 21 are slidably connected. Therefore, the magnitude of the torsion angle of the torsion bar 23 will be converted into the angle difference of the relative angular displacement between the input shaft 22 and the gear shaft 21.

[0057] A brushless motor PPK assembly 9 is fixedly installed on the side wall of the intermediate housing assembly 3. The end of the sensor harness assembly 6 away from the intermediate housing assembly 3 is connected to the brushless motor PPK assembly 9. The sensor harness assembly 6 is connected to the Hella sensor assembly 27 for signal transmission. A sealing plug is provided at the connection between the sensor harness assembly 6 and the intermediate housing assembly 3. A rubber sealing ring is provided between the sensor housing and the intermediate housing to form a seal.

[0058] Compared to brushed motors, brushless motors allow for the integration of the ECU into the motor, resulting in a more integrated overall structure. They also enable higher speeds and superior performance. Angle control offers higher precision compared to brushless motors. Furthermore, they eliminate the need for an additional ECU, as power supply from the ECU to the motor is no longer required, reducing wiring costs.

[0059] Specifically, refer to Figure 6 The main housing assembly 7 is equipped with a rack support seat 12 and a rack 11 that meshes with the gear shaft 21. The rack support seat 12 includes a support base fixedly installed inside the main housing assembly 7. A spring is fixedly connected inside the support base. An arc-shaped support surface that fits the outer arc surface of the rack 11 is fixedly connected outside the spring. This is used to adjust the meshing clearance between the gear shaft 21 and the rack 11 to prevent excessive looseness and abnormal noise. The main housing assembly 7 is equipped with a double O-ring bushing, which works with the rack adjustment mechanism to radially position the rack 11. The main housing assembly 7 is equipped with a needle roller bearing, which works with the bearing on the intermediate housing assembly to fix the gear shaft 21.

[0060] Specifically, refer to Figure 2 An inner tie rod 13 is fitted at one end of the rack 11 extending to the outside of the main housing assembly 7. An outer tie rod 14 is fitted at the end of the inner tie rod 13 away from the rack 11. A protective cover 15 is fitted at the end of the rack 11 located outside the main housing assembly 7. A single-ear stepless clamp is provided at the connection between the protective cover 15 and the main housing assembly 7. A steel band elastic clamp is provided at the connection between the protective cover 15 and the inner tie rod 13. A seal is formed between the rack 11, the protective cover 15, the main housing assembly 7, and the inner tie rod 13. The inner and outer tie rods are threaded together, with an adjustment range. After determining the length, the tie rod is locked with a tie rod nut.

[0061] Specifically, refer to Figure 3 The main housing assembly 7 has three mounting holes 10 on its side wall. The mounting surface of the main housing assembly 7 is flat and has an annular sealing groove. The three mounting holes 10 are used for locking. This fit design allows it to cope with different chassis architectures.

[0062] A dust cover 16 is fixedly connected to the top of the sensor housing assembly 5. The dust cover 16 is used to protect the oil seal 53 and form a seal between the sensor housing and the input shaft.

[0063] The steering gear structure using P-EPS uses a gear shaft and rack for transmission. The steering wheel input shaft, power assist gear shaft, torque angle sensor and worm gear pair are integrated into a single spindle assembly, which is compact, improves space utilization and provides greater power assist.

[0064] EPS uses a brushless motor for torque input. The worm assembly 4 includes a worm 41 mounted on the output shaft of the brushless motor PPK assembly 9. The worm assembly 4 is installed inside the intermediate housing assembly 3 and is radially fixed by bearings inside the intermediate housing assembly 3 and bearings on the worm assembly 4. The bearing threaded retaining ring is screwed into the intermediate housing assembly 3 to fix the bearings on the worm assembly 4 and axially fix the worm assembly 4. The half coupling on the worm assembly 4 is connected to the half coupling on the output shaft of the PPK. The gear shaft 21 is externally mounted with a worm wheel 28 that is connected to the worm 41 for transmission. The worm wheel 28 is press-fitted onto the spindle assembly 2 to achieve speed reduction and torque increase, converting the motor torque into 20 times the gear torque. Since the gear shaft 21 and the rack 11 mesh, the torque of the gear shaft 21 is converted into the push and pull force of the rack 11. The rack 11 drives the tie rods connected to both ends of the rack 11. The ball joint of the tie rod is connected to the wheel steering swing arm to realize the left and right steering swing of the wheel.

[0065] The torque angle sensor in the Hella sensor assembly 27 is a Hall-effect non-contact torque sensor. The rotor mounting cover 25 is press-fitted into the outside of the gear shaft 21. The Hella sensor rotor 26 is welded to the rotor mounting cover 25 and forms an integral part with the gear shaft 21, remaining stationary relative to the input shaft 22. The Hella sensor assembly 27 is welded to the input shaft 22 and undergoes angular displacement relative to the gear shaft 21 with the input shaft 22. This torque angle sensor forms an inductor coil through printed circuits on the PCB. When a voltage is applied to the two ends of the coil, a magnetic field required for the Hall effect is generated in the air. The input shaft rotor assembly in the Hella sensor assembly 27 welded to the input shaft 22 and the output shaft rotor welded to the gear shaft cut the magnetic field to obtain two sets of absolute angle signals. The ECU processes the two sets of signals synchronously to obtain the angle difference between the angular displacement of the input shaft 22 and the gear shaft 21. Then, using the design stiffness of the torsion bar 23 of approximately 2.5 Nm / deg, the algorithm is used to back-calculate the input force value of the input shaft 22, realizing the detection of input torque when the driver is driving, and adjusting the steering assist based on the magnitude of this torque.

[0066] The Hella sensor assembly 27 detects the steering wheel input angle and steering angle using a gear-type mechanism. Its inner gear is welded to the input shaft 22 along with the Hella sensor assembly 27 and rotates relative to the inner gear. The outer gear is held in a slot in the intermediate housing along with the gear housing on the Hella sensor assembly 27 and remains stationary relative to the inner gear. By calculating the angle of rotation of the outer gear relative to the inner gear, the angle of steering wheel input when someone is driving is obtained and converted into the target angle position of the steering gear.

[0067] Specifically, refer to Figure 11 To execute the steering request process, the autonomous driving mode uses a closed-loop control system. The torque and angle sensors read the current angle signal, correct the difference between the input target angle and the actual angle, and control the motor to run to the actual angle to achieve high-precision operation.

[0068] It should be noted that the worm gear 28 is press-fitted into the gear shaft 21, forming a single unit. The rotor mounting cover 25 is pressed into the gear shaft 21. The rotor mounting cover 25 is required when the addendum circle of the gear shaft 21 is larger than the inner diameter of the worm gear 28. The worm gear 28 is pressed into the gear shaft 21 from the coarse end. When the addendum circle of the gear shaft 21 is smaller than the inner diameter of the worm gear 28, the rotor mounting cover 25 is not needed. The journal for mounting the Hella sensor rotor is simply machined at the top of the coarse end of the gear shaft 21. The gear shaft 21 is pressed into the gear shaft from the toothed end. (Refer to the attached document.) Figure 9 As shown, the spline shaft 81 of C-EPS does not have a rotor mounting cover 25 because the spline size is smaller than the inner diameter of the worm gear 28.

[0069] Torsion bar 23 is press-fitted into gear shaft 21, forming a single unit with gear shaft 21. Input shaft 22 is press-fitted into sliding bearing of gear shaft 21, ensuring that input shaft 22 can rotate relative to gear shaft 21, but can be axially disengaged. At this point, the assembly components include: gear shaft 21, torsion bar 23, sliding bearing, input shaft 22, O-ring, and worm gear 28. To fix this assembly as a single unit, input shaft 22 and gear shaft 21 are axially fixed. Through holes need to be machined on this assembly to pass through torsion bar 23 and input shaft 22, and then press-fitted with cylindrical pin 24. This application uses a special drilling and pinning station for one-piece molding to ensure the consistency and reliability of the finished product. After pinning, Hella sensor rotor 26 is assembled to rotor mounting cover 25; Hella sensor assembly 27 is assembled to input shaft 22, and both are fixed to the corresponding journals using laser welding.

[0070] The mounting methods of the power steering housing assembly and the main housing assembly 7 have two characteristics:

[0071] 1. The mounting surface of the main housing is flat, with only one O-ring groove for sealing, bearing holes for positioning, and three mounting holes for locking. This design allows for adaptation to different chassis architectures, steering strokes, and assembly hard points, provided that the rack thrust is sufficient and the performance meets the requirements. Only the main housing needs to be modified to adapt to the chassis, greatly enhancing the versatility of this product.

[0072] 2. For cross-platform compatibility, the main housing assembly 7 is changed to the lower housing assembly 8, and the gear shaft 21 on the spindle assembly 2 is changed to the spline shaft 81. This P-EPS can be changed to C-EPS to adapt to more vehicle models.

[0073] 3. Different adaptations can be made for different chassis. By changing the structure and mounting points of the main housing, such as changing the size and position of the three mounting holes on the main housing, it can match the chassis mounting form of different customers, thereby adapting to the mounting space and mounting points of different chassis. The total travel of the rack inside the main housing and the center distance between the inner and outer balls of the tie rod can be changed to meet the steering trapezoid and wheel track of different chassis. The main housing assembly and gear shaft can be modified to make C-EPS to adapt to mechanical steering gears, which can meet the low-cost requirements of manufacturers.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 said element.

[0075] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A P-EPS structure for unmanned delivery vehicles, comprising an electric power steering gear assembly (1), characterized in that: The electric steering assembly (1) also includes a power steering housing assembly and a main housing assembly (7). The main housing assembly (7) can be replaced by a replacement component to adapt to the C-EPS steering system. The power steering housing assembly includes a spindle assembly (2), an intermediate housing assembly (3), a worm gear assembly (4), a sensor housing assembly (5), and a sensor wiring harness assembly (6). The intermediate housing assembly (3) is fixedly installed on the top of the main housing assembly (7), the sensor housing assembly (5) is fixedly installed on the top of the intermediate housing assembly (3), the spindle assembly (2) is assembled inside the intermediate housing assembly (3), the worm gear assembly (4) is assembled inside the intermediate housing assembly (3), and the sensor harness assembly (6) is assembled on the side wall of the intermediate housing assembly (3). The spindle assembly (2) includes a gear shaft (21) extending into and rotatably connected to the main housing assembly (7). An input shaft (22) is mounted inside the gear shaft (21). A rotor mounting cover (25) is mounted outside the gear shaft (21). A Hella sensor rotor (26) is mounted outside the rotor mounting cover (25). A Hella sensor assembly (27) is mounted outside the input shaft (22). A worm gear (28) is mounted outside the gear shaft (21). The sensor housing assembly (5) includes a sensor housing (51) mounted on the top of the intermediate housing assembly (3), a deep groove ball bearing (52) is installed inside the sensor housing (51), and an oil seal (53) is installed inside the sensor housing (51). The replacement components include a lower housing assembly (8) and a splined shaft (81).

2. The P-EPS structure for the unmanned delivery vehicle according to claim 1, wherein: The lower housing assembly (8) replaces the main housing assembly (7) and is installed at the bottom of the intermediate housing assembly (3). The spline shaft (81) replaces the gear shaft (21) and is connected to the input shaft (22). 3.The P-EPS structure for the unmanned delivery vehicle of claim 1, wherein: The spindle assembly (2) also includes a torsion bar (23) assembled inside the input shaft (22), and a cylindrical pin (24) is assembled inside the torsion bar (23). A sliding bearing is provided at the connection between the input shaft (22) and the gear shaft (21).

4. The P-EPS structure for the unmanned delivery vehicle according to claim 1, wherein: A brushless motor PPK assembly (9) is fixedly installed on the side wall of the intermediate housing assembly (3). The end of the sensor harness assembly (6) away from the intermediate housing assembly (3) is connected to the brushless motor PPK assembly (9). The sensor harness assembly (6) is connected to the Hella sensor assembly (27) for signal transmission. A sealing plug is provided at the connection between the sensor harness assembly (6) and the intermediate housing assembly (3).

5. The P-EPS structure for the unmanned delivery vehicle according to claim 4, wherein: The worm gear assembly (4) includes a worm gear (41) mounted on the output shaft of the brushless motor PPK assembly (9), and the worm gear (41) is connected to the brushless motor PPK assembly (9) via a coupling. 6.The P-EPS structure for the unmanned delivery vehicle of claim 1, wherein: The main housing assembly (7) is equipped with a rack support seat (12) inside, and a rack (11) that meshes with the gear shaft (21) is also equipped inside the main housing assembly (7).

7. The P-EPS structure for an unmanned delivery vehicle of claim 6, wherein: An inner tie rod (13) is fitted at one end of the rack (11) extending to the outside of the main housing assembly (7). An outer tie rod (14) is fitted at the end of the inner tie rod (13) away from the rack (11). A protective cover (15) is fitted at one end of the rack (11) located outside the main housing assembly (7). A single-ear stepless clamp is provided at the connection between the protective cover (15) and the main housing assembly (7). A steel band elastic clamp is provided at the connection between the protective cover (15) and the inner tie rod (13). 8.The P-EPS structure for an unmanned delivery vehicle of claim 1, wherein: The main housing assembly (7) has three mounting holes (10) on its side wall. The mounting surface of the main housing assembly (7) is a flat surface and has an annular sealing groove. 9.The P-EPS structure for the unmanned delivery vehicle of claim 1, wherein: A dust cover (16) is mounted on the top of the sensor housing assembly (5).

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