A P-EPS structure for unmanned express delivery vehicles

Abstract

The present invention relates to the technical field of electric power steering, and discloses a P-EPS structure for unmanned express delivery vehicles, including an electric steering gear assembly, the electric steering gear assembly also includes a power housing assembly and a main housing assembly, the main housing assembly can be replaced by a replacement component to adapt to a C-EPS steering system, and the power housing assembly includes a spindle assembly, an intermediate housing assembly, a worm assembly, a sensor housing assembly and a sensor harness assembly. The P-EPS structure for unmanned express delivery vehicles uses a universal structure, a unified intermediate housing and a sensor housing, so that the product can be arranged on multiple platforms, made into a C-EPS, adapted to a mechanical steering machine, and can meet the low-cost requirements of manufacturers. By integrating the steering wheel input shaft, the power gear shaft, the torque angle sensor and the worm gear pair into a whole, it has the advantages of compact structure, improved space utilization, and large power assistance.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power steering, and in particular to a P-EPS structure for an unmanned express delivery vehicle. Background Art

[0002] With the growing growth of China's unmanned express delivery industry, the demand for autonomous driving is also increasing. Unmanned express vehicles have a small body. Due to their small size, high load, and compact structure, R-EPS and DP-EPS have sufficient power assistance, but their large size and cramped space, small C-EPS has low reliability, high failure rate, and low torque, making it unsuitable for heavy-load use. The demand for heavy loads is destined to use the P-EPS steering gear structure to best meet its chassis layout.

[0003] At present, most of the structures of unmanned driving P-EPS electric power steering devices are separated in mechanical, motor and controller parts, and the shell is an integral shell. The traditional brush controller has low space utilization and requires an additional ECU controller, which needs to be protected. In addition, the traditional P-EPS structure is single, and a set of molds can only make a single product. Therefore, the versatility is poor and cannot meet the needs of multi-platform layout. Therefore, a P-EPS structure for unmanned express delivery vehicles is urgently needed to solve the above problems. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a P-EPS structure for an unmanned express delivery vehicle, which has the advantages of compact structure and strong applicability, and solves the problems that R-EPS and DP-EPS have sufficient power assistance but are large in size and cramped in space, and small C-EPS has low reliability, high failure rate, and low torque, and is not suitable for heavy load use. In addition, the traditional P-EPS has a single structure, and a set of molds can only make a single product, so it has poor applicability.

[0006] (II) Technical solution

[0007] The technical solution of the present invention to solve the above technical problems is as follows: a P-EPS structure for an unmanned express delivery vehicle, comprising an electric steering gear assembly, the electric steering gear assembly further comprising a power-assist housing assembly and a main housing assembly, the main housing assembly can be replaced by a replacement component to adapt to a C-EPS steering system, the power-assist housing assembly comprises a spindle assembly, an intermediate housing assembly, a worm assembly, a sensor housing assembly and a sensor harness assembly;

[0008] The intermediate housing assembly is fixedly mounted on the top of the main housing assembly, the sensor housing assembly is fixedly mounted on the top of the intermediate housing assembly, the mandrel assembly is assembled and arranged inside the intermediate housing assembly, the worm assembly is assembled and arranged inside the intermediate housing assembly, and the sensor harness assembly is assembled and arranged on the side wall of the intermediate housing assembly;

[0009] The spindle assembly includes a gear shaft extending into the main housing assembly and rotatably connected, the input shaft is assembled inside the gear shaft, a rotor mounting cover is assembled outside the gear shaft, a Hella sensor rotor is assembled outside the rotor mounting cover, a Hella sensor assembly is assembled outside the input shaft, and a worm gear is assembled outside the gear shaft;

[0010] The sensor housing assembly comprises a sensor housing assembled on the top of the intermediate housing assembly, a deep groove ball bearing is assembled inside the sensor housing, and an oil seal is assembled inside the sensor housing;

[0011] The replacement assembly includes a lower housing assembly and a spline shaft.

[0012] The beneficial effects of the present invention are:

[0013] The P-EPS structure used in unmanned delivery vehicles uses a universal structure, a unified intermediate housing and a sensor housing, so that the product can be arranged on multiple platforms and made into a C-EPS, which is adapted to a mechanical steering machine and can meet the low-cost needs of manufacturers.

[0014] The P-EPS structure used in unmanned delivery vehicles uses rack and pinion transmission. By integrating the steering wheel input shaft, power gear shaft, torque angle sensor and worm gear pair into a whole, it has the advantages of compact structure, improved space utilization and large power assistance.

[0015] Based on the above technical solution, the present invention can also be 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 spline shaft replaces the gear shaft and is connected to the input shaft.

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

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

[0019] The beneficial effect of adopting the above further scheme is that a torsion bar and a sliding bearing are interference-pressed on the gear shaft, the inner hole of the input shaft head and the outer circle of the torsion bar head match, the outer circle of the input shaft tail and the inner hole of the sliding bearing match, and at the same time, a cylindrical pin is driven into the input shaft spline 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, one 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 beneficial effect of adopting the above further solution is that, by using a brushless motor, the ECU can be integrated into the motor, and the overall structure is more integrated, compared with a brushless motor.

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

[0023] The beneficial effect of adopting the above further solution is that the worm gear is pressed onto the core shaft 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 provided inside the main housing assembly, and a rack meshing with the gear shaft is provided inside the main housing assembly.

[0025] The beneficial effect of adopting the above further solution is to adjust the meshing clearance between the gear shaft and the rack to prevent abnormal noise caused by excessive looseness.

[0026] Furthermore, an inner pull rod is installed at one end of the rack extending to the outside of the main housing assembly, an outer pull rod is installed at one end of the inner pull rod away from the rack, a protective cover is sleeved on 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 belt elastic clamp is provided at the connection between the protective cover and the inner pull rod.

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

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

[0029] The beneficial effect of adopting the above further solution is that three threaded holes are used for locking, and this matching design allows for coping with different chassis architectures.

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

[0031] The beneficial effect of adopting the above further solution is that a seal is formed between the sensor housing and the input shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of the electric steering gear assembly of the present invention;

[0033] Figure 2 It is a cross-sectional view of the electric steering gear assembly structure of the present invention;

[0034] Figure 3 A top view of the electric steering gear assembly structure of the present invention;

[0035] Figure 4 It is a schematic diagram of the main housing assembly structure of the present invention;

[0036] Figure 5 It is a schematic diagram of the structure of the power-assisting housing assembly of the present invention;

[0037] Figure 6 This is a cross-sectional view of the power-assist housing assembly structure of the present invention;

[0038] Figure 7 It is a cross-sectional view of the core shaft assembly structure of the present invention;

[0039] Figure 8 It is a schematic diagram of the structure of the replacement component of the present invention;

[0040] Fig. 9 It is a schematic diagram of the spline shaft structure of the present invention;

[0041] Fig.10 It is a schematic diagram of the lower shell structure of the present invention;

[0042] Fig.11 It is a cross-sectional view of the lower shell structure of the present invention;

[0043] Fig.12 It is a structural schematic diagram of the sensor housing assembly of the present invention;

[0044] Fig.13 It is a structural flow chart of the present invention.

[0045] In the figure: 1. Electric steering gear assembly; 2. Mandrel 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 assembly; 41. Worm; 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. Spline shaft; 9. Brushless motor PPK assembly; 10. Mounting hole; 11. Rack; 12. Rack support seat; 13. Inner pull rod; 14. Outer pull rod; 15. Protective cover; 16. Dust cover. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In the embodiment, Figure 1-13 A P-EPS structure for an unmanned express delivery vehicle is provided, comprising an electric steering gear assembly 1, the electric steering gear assembly 1 further comprising a power-assist 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-assist housing assembly comprises a spindle assembly 2, an intermediate housing assembly 3, a worm assembly 4, a sensor housing assembly 5 and a sensor harness assembly 6;

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

[0049] The spindle assembly 2 includes a gear shaft 21 extending into the main housing assembly 7 and rotatably connected thereto, an input shaft 22 is assembled inside the gear shaft 21, a rotor mounting cover 25 is assembled outside the gear shaft 21, a Hella sensor rotor 26 is assembled outside the rotor mounting cover 25, a Hella sensor assembly 27 is assembled outside the input shaft 22, and a worm gear 28 is assembled outside the gear shaft 21;

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

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

[0052] Specifically, refer to Figure 8 The replacement components include a lower housing assembly 8 and a spline 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 spline shaft 81 replaces the gear shaft 21 and is connected to the input shaft 22. This installation method can realize the transformation from P-EPS to C-EPS.

[0053] Reference Fig.11 As shown, an O-ring bushing is disposed at the top of the lower housing assembly 8 , and an oil seal 53 is disposed at the bottom of the lower housing assembly 8 .

[0054] A torsion bar 23 is assembled inside the input shaft 22 , a cylindrical pin 24 is assembled inside the torsion bar 23 , and a sliding bearing is arranged at the connection between the input shaft 22 and the gear shaft 21 .

[0055] A spline of the steering wheel input shaft is reserved to match the corresponding steering wheel input to achieve manual + automatic driving dual-mode operation. A torsion bar 23 and a sliding bearing are pressed into the gear shaft 21 by interference fit. The sliding bearing is located in the sensor housing. The inner hole of the head of the input shaft 22 matches the outer circle of the head of the torsion bar, and the inner hole of the sliding bearing at the rear of the outer circle of the input shaft 22 matches. At the same time, the cylindrical pin 24 is driven into the spline of the input shaft 22 and the torsion bar 23 to achieve the fixation of the input shaft 22 relative to the torsion bar 23.

[0056] When the input shaft 22 is connected to the steering wheel, since 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 produce 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, so the torsion angle of the torsion bar 23 will be converted into the angle difference of the relative angular displacement of the input shaft 22 and the gear shaft 21.

[0057] A brushless motor PPK assembly 9 is fixedly mounted on the side wall of the intermediate housing assembly 3, and one 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 signal-connected to the Hella sensor assembly 27. A sealing plug is provided at the connection between the sensor harness assembly 6 and the intermediate housing assembly 3, and a rubber sealing ring is provided between the sensor housing and the intermediate housing to form a seal.

[0058] Compared with brushed motors, brushless motors can integrate the ECU into the motor, making the overall structure more integrated; they can also increase the speed and achieve better performance; using angle control, the accuracy is higher than that of brushless motors; they save extra ECUs, and there is no need to supply power from the ECU to the motor, reducing wires.

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

[0060] Specifically, refer to Figure 2 The end of the rack 11 extending to the outside of the main housing assembly 7 is equipped with an inner pull rod 13, and the end of the inner pull rod 13 away from the rack 11 is equipped with an outer pull rod 14. The end of the rack 11 located outside the main housing assembly 7 is sleeved with a protective cover 15, and a single-ear stepless clamp is provided at the connection between the protective cover 15 and the main housing assembly 7, and a steel belt type elastic clamp is provided at the connection between the protective cover 15 and the inner pull rod 13. A seal is formed between the protective cover 15 of the rack 11, the main housing assembly 7 and the inner pull rod 13. The inner and outer pull rods are threadedly connected, and after the adjustment amount is left to determine the length, they are locked with a pull rod nut.

[0061] Specifically, refer to Figure 3 Three mounting holes 10 are arranged on the side wall of the main housing assembly 7. The mounting surface of the main housing assembly 7 is a flat surface and is provided with an annular sealing groove. The three mounting holes 10 are used for locking. This matching design allows for coping 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 of P-EPS is used, with the gear shaft and rack for transmission. The steering wheel input shaft, power gear shaft, torque angle sensor and worm gear pair are integrated into an integral core shaft assembly. It has a compact structure, improved space utilization, and provides great power assistance.

[0064] EPS uses a brushless motor for torque input. The worm assembly 4 includes a worm 41 assembled on the output shaft of the brushless motor PPK assembly 9. The installation method is that the worm assembly 4 is installed in the intermediate housing assembly 3, and is radially fixed by the bearings in the intermediate housing assembly 3 and the 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 of the output shaft on the PPK. The external assembly of the gear shaft 21 is provided with a worm wheel 28 that is transmission-connected to the worm 41. The worm wheel 28 is pressed onto the core shaft assembly 2 to achieve speed reduction and torque increase, and convert the motor torque into 20 times the gear torque. Due to the meshing of the gear shaft 21 and the rack 11, the gear shaft 21 torque is converted into the push-pull force of the rack 11. The rack 11 drives the pull rod connected to the two ends of the rack 11, and the pull rod ball head is connected to the wheel steering swing arm to achieve left and right steering swing of the wheel.

[0065] The torque angle sensor in the Hella sensor assembly 27 is a Hall-type non-contact torque sensor. The rotor mounting cover 25 is pressed into the outside of the gear shaft 21 by interference fit. The Hella sensor rotor 26 is welded on the rotor mounting cover 25, and is integrated with the gear shaft 21, and is stationary relative to the input shaft 22. The Hella sensor assembly 27 is welded on the input shaft 22, and makes an angular displacement relative to the gear shaft 21 with the input shaft 22. This torque angle sensor forms an inductor coil by a printed circuit on a PCB. After a voltage is applied to both ends of the coil, a magnetic field required for the Hall effect is formed in the air. The input shaft rotor assembly in the Hella sensor assembly 27 welded on the input shaft 22 and the output shaft rotor welded on the gear shaft cut the magnetic field to obtain two sets of absolute angle signals. The ECU synchronously processes the two sets of signals to obtain the angle difference between the angular displacements of the input shaft 22 and the gear shaft 21, and then uses the design stiffness of the torsion bar 23 of about 2.5Nm / deg to reversely infer the input force value of the input shaft 22 using an algorithm, thereby realizing input torque detection when a person is driving, and adjusting the magnitude of the steering assist according to the magnitude of this torque.

[0066] The Hella sensor assembly 27 is in the form of gear matching for detecting the steering wheel input angle and the steering angle. Its inner ring gear is welded to the input shaft 22 along with the Hella sensor assembly 27 and rotates relative to the inner ring gear. The outer ring gear is stuck in the slot of the intermediate housing along with the gear housing on the Hella sensor assembly 27 and is stationary relative to the inner ring gear. By calculating the rotation angle of the outer ring gear relative to the inner ring gear, the angle of the steering wheel input when someone is driving is obtained and converted into the target angle position of the steering gear operation.

[0067] Specifically, refer to Fig.11To execute the steering request process, the unmanned driving mode uses a closed-loop control system. The torque angle sensor reads the current angle signal, corrects the difference between the input target angle and the actual angle, and controls the motor to run to the actual angle to achieve high-precision operation.

[0068] It should be noted that the worm wheel 28 is pressed into the gear shaft 21 with interference fit, and the worm wheel 28 and the gear shaft 21 form a whole. The rotor mounting cover 25 is pressed into the gear shaft 21 to the top of the worm wheel 28. Here, when the tooth top circle of the gear shaft 21 below is larger than the inner diameter of the worm wheel 28, the rotor mounting cover 25 is required. The worm wheel 28 is pressed in from the thick end of the gear shaft 21. When the tooth top circle of the gear shaft 21 is smaller than the inner diameter of the worm wheel 28, the rotor mounting cover 25 is not required. The top of the thick end of the gear shaft 21 is machined into the journal for the Hella sensor rotor installation. The gear shaft 21 is pressed in from the toothed end of the gear shaft. Refer to the attached Fig. 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 wheel 28 .

[0069] The torsion bar 23 is pressed into the gear shaft 21 through an interference fit, and the gear shaft 21 and the torsion bar 23 form a whole. The input shaft 22 is ensured to be able to rotate relative to the gear shaft 21 by means of a sliding bearing pressed into the gear shaft 21, but can be detached axially. At this time, the assembly parts include: gear shaft 21, torsion bar 23, sliding bearing, input shaft 22, O-ring, worm gear 28. In order to fix this assembly as a whole and axially fix the input shaft 22 and the gear shaft 21, it is necessary to process a through hole on the basis of this assembly, passing through the torsion bar 23 and the input shaft 22, and then use a cylindrical pin 24 to be pressed in through an interference fit. This application uses a special drilling and pinning table for one-piece molding to ensure the consistency and reliability of the finished product. After the pinning is completed, the Hella sensor rotor 26 is assembled to the rotor mounting cover 25; the Hella sensor assembly 27 is assembled to the input shaft 22, and both are fixed to the corresponding shaft necks by laser welding.

[0070] The installation method of the power-assist housing assembly and the main housing assembly 7 has two characteristics:

[0071] 1. The mounting surface of the main housing is flat, with only one O-ring groove for sealing, a bearing hole for positioning, and three mounting holes 10 for locking. This matching design allows the frame to be adapted by simply changing the main housing when dealing with different chassis structures, different steering strokes, and different assembly hard points, as long as the rack thrust is sufficient and the performance meets the requirements, which greatly enhances the versatility of this product;

[0072] 2. Across platforms, the main housing assembly 7 is changed to the lower housing assembly 8, and the gear shaft 21 on the core shaft 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 main housing structure and installation points. For example, the size and position of the three installation holes on the main housing can be changed to match the chassis installation forms of different customers, so as to adapt to the installation space and installation points of different chassis. The total stroke of the rack in the main housing and the inner and outer ball center distance of the tie rod can be changed to meet the steering trapezoid and wheelbase of different chassis. The main housing assembly and the gear shaft can be changed to make C-EPS and adapt to the mechanical steering gear to meet the low-cost needs of manufacturers.

[0074] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

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

Claims

1. A P-EPS structure for an unmanned express delivery vehicle, comprising an electric steering gear assembly (1), characterized in that: The electric steering gear assembly (1) further comprises a power-assist housing assembly and a main housing assembly (7), wherein the main housing assembly (7) can be replaced by a replacement component to adapt to a C-EPS steering system, and the power-assist housing assembly comprises a spindle assembly (2), an intermediate housing assembly (3), a worm assembly (4), a sensor housing assembly (5) and a sensor harness assembly (6); The intermediate housing assembly (3) is fixedly mounted on the top of the main housing assembly (7), the sensor housing assembly (5) is fixedly mounted on the top of the intermediate housing assembly (3), the spindle assembly (2) is assembled and arranged inside the intermediate housing assembly (3), the worm assembly (4) is assembled and arranged inside the intermediate housing assembly (3), and the sensor harness assembly (6) is assembled and arranged on the side wall of the intermediate housing assembly (3); The spindle assembly (2) comprises a gear shaft (21) extending into the interior of the main housing assembly (7) and being rotatably connected thereto; the interior of the gear shaft (21) is provided with an input shaft (22); the exterior of the gear shaft (21) is provided with a rotor mounting cover (25); the exterior of the rotor mounting cover (25) is provided with a Hella sensor rotor (26); the exterior of the input shaft (22) is provided with a Hella sensor assembly (27); and the exterior of the gear shaft (21) is provided with a worm gear (28); The sensor housing assembly (5) comprises a sensor housing (51) mounted on the top of the intermediate housing assembly (3), a deep groove ball bearing (52) being mounted inside the sensor housing (51), and an oil seal (53) being mounted inside the sensor housing (51); The replacement component comprises a lower housing assembly (8) and a spline shaft (81).

2. A P-EPS structure for an unmanned express delivery vehicle according to claim 1, characterized in that: 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 an unmanned express delivery vehicle according to claim 1, characterized in that: The core shaft assembly (2) further comprises a torsion bar (23) mounted inside the input shaft (22), a cylindrical pin (24) being mounted inside the torsion bar (23), and a sliding bearing being provided at the connection between the input shaft (22) and the gear shaft (21).

4. The P-EPS structure for an unmanned express delivery vehicle according to claim 1, characterized in that: A brushless motor PPK assembly (9) is fixedly mounted on the side wall of the intermediate housing assembly (3); one 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 signal-connected to a Hella sensor assembly (27); and a sealing plug is provided at the connection between the sensor harness assembly (6) and the intermediate housing assembly (3).

5. A P-EPS structure for an unmanned express delivery vehicle according to claim 4, characterized in that: The worm assembly (4) comprises a worm (41) mounted on an output shaft of a brushless motor PPK assembly (9); the worm (41) is connected to the brushless motor PPK assembly (9) via a shaft coupling.

6. The P-EPS structure for an unmanned express delivery vehicle according to claim 1, characterized in that: A rack support seat (12) is mounted inside the main housing assembly (7), and a rack (11) meshing with the gear shaft (21) is mounted inside the main housing assembly (7).

7. A P-EPS structure for an unmanned delivery vehicle according to claim 6, characterized in that: An inner pull rod (13) is mounted on one end of the rack (11) extending to the outside of the main housing assembly (7); an outer pull rod (14) is mounted on one end of the inner pull rod (13) away from the rack (11); a protective cover (15) is sleeved on one end of the rack (11) located outside the main housing assembly (7); a single-ear stepless clamp is disposed at the connection between the protective cover (15) and the main housing assembly (7); and a steel belt elastic clamp is disposed at the connection between the protective cover (15) and the inner pull rod (13).

8. The P-EPS structure for an unmanned express delivery vehicle according to claim 1, characterized in that: Three mounting holes (10) are provided on the side wall of the main housing assembly (7); the mounting surface of the main housing assembly (7) is a flat surface and is provided with an annular sealing groove.

9. The P-EPS structure for an unmanned express delivery vehicle according to claim 1, characterized in that: A dust cover (16) is mounted on the top of the sensor housing assembly (5).

Images