Low-cab electric steering gear

Abstract

The invention provides a low-cab electric steering gear. The low-cab electric steering gear comprises a power-assisted motor, an EPS controller, an input shaft, an upper cover bearing, an upper cover, a worm gear, a worm, a lower end worm gear, a shell, a lead screw upper end bearing, an output shaft, a lead screw lower end bearing and an oil seal. The output end of the power-assisted motor is connected with the input shaft through a worm and a worm gear; the EPS controller is used for controlling the power-assisted motor to output power-assisted steering according to angle information and torque information transmitted by the steering wheel; the input shaft is fixed to the shell through a lead screw upper end bearing and a lead screw lower end bearing. The input shaft is connected with the output shaft through the lower end worm and gear. An oil seal is arranged at the lower end of the shell; and the upper cover is connected and fixed on the shell through a bolt. Through the high-integration compact EPS structure, the vertical space compression problem is effectively solved, and it is guaranteed that the light truck model meets the human head space size and the whole truck trafficability.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and more particularly, to a low-cab electric power steering gear. Background Art

[0002] In the design of the steering system of light trucks (light-duty trucks), especially when driving into height-restricted scenarios such as underground garages, the height of the cab floor needs to be reduced as much as possible to meet the passing requirements, which poses strict constraints on the layout space of the steering system in the height direction.

[0003] Currently, the electric power steering gears used in electric light truck products are all installed vertically. Due to the integration of the angle-torque sensor and the use of the ball screw structure, the space occupied by the EPS input shaft to the output shaft in the height direction is relatively large, making it difficult to meet the requirements of the low-cab layout and unable to meet the needs of the current market vehicle usage scenarios. In addition, a large number of electronic control components in the existing design not only increase the system complexity and the cost of a single piece, but also increase the potential failure rate and affect the convenience of after-sales maintenance. Therefore, there is an urgent need for development. Summary of the Invention

[0004] Aiming at the defects in the prior art, the object of the present invention is to provide a low-cab electric power steering gear, which aims to effectively solve the problem of vertical space compression through a highly integrated and compact EPS structure, especially the compression of the space in the height direction from the input shaft to the output shaft of the electric power steering gear, and ensure that the light truck model meets the head space size of the human body and the passing performance of the whole vehicle.

[0005] To achieve the above object of the invention, the present invention adopts the following technical solutions:

[0006] The present invention provides a low-cab electric power steering gear, including: a booster motor, an EPS controller, an input shaft, an upper cover bearing, an upper cover, a worm gear, a worm, a lower end worm gear, a housing, a screw rod upper bearing, an output shaft, a screw rod lower bearing, and an oil seal;

[0007] The booster motor is fixedly connected to the housing; the output end of the booster motor is connected to the input shaft through the worm and the worm gear;

[0008] The EPS controller is used to control the output of the steering assist of the booster motor according to the angle information and torque information transmitted by the steering wheel;

[0009] The input shaft is fixed to the housing through the screw rod upper bearing, the screw rod lower bearing; the input shaft is connected to the output shaft through the lower end worm gear;

[0010] A first oil seal part is provided at the screw rod upper bearing at the upper part of the lower cavity of the housing; an oil seal is also provided at the lower end of the housing;

[0011] The upper cover is fixed to the housing by bolt connection, and a second oil seal part is provided at the upper cover.

[0012] Preferably, it further includes a sealing ring and a retaining ring;

[0013] The upper bearing of the lead screw is threadedly connected to the retaining ring and the housing; the retaining ring forms a first oil seal part at the upper part of the lower cavity of the housing through the sealing ring and the input shaft.

[0014] Preferably, it further includes an upper cover sealing ring;

[0015] The upper cover sealing ring fixes the upper end of the input shaft through the clearance fit of the upper cover bearing, and forms a second oil seal part at the upper part of the lower cavity of the housing.

[0016] Preferably, an O-ring is provided between the upper cover and the housing to form a third oil seal part.

[0017] Preferably, it further includes: a first connector and a second connector;

[0018] The angle information and torque information of the steering wheel are sent to the EPS controller through the first connector via the vehicle CAN communication network for the sensor signals;

[0019] The battery supplies power to the EPS controller through the second connector.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] Through a special structural design, the present invention realizes the compact design of the electric power steering gear, effectively reduces the space occupied by the steering system in the height direction, significantly reduces the height of the cab floor, meets the passing requirements of height-limited scenarios such as the vehicle driving into an underground garage, and also reduces the part cost and maintenance convenience due to the optimization of the electronic control logic and mechanical structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects and advantages of the present invention will become more apparent:

[0023] Figure 1 It is a structural schematic diagram of the novel low-cab electric power steering gear described in the embodiment;

[0024] Figure 2 It is a schematic diagram of the EPS electronic control assist signal logic in the embodiment.

[0025] As shown in the figure:

[0026] 1 - input shaft;

[0027] 2 - upper cover sealing ring;

[0028] 3 - upper cover bearing;

[0029] 4 - Upper cover;

[0030] 5 - Worm gear;

[0031] 6 - Worm;

[0032] 7 - Housing;

[0033] 8 - Sealing ring;

[0034] 9 - Retaining ring;

[0035] 10 - Upper bearing of the lead screw;

[0036] 11 - Output shaft;

[0037] 12 - Lower bearing of the lead screw;

[0038] 13 - Oil seal. Detailed implementation manners

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. Usually, the components of the embodiments of this application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application that is claimed, but merely represents the selected embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0041] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, all directional indications (such as up, down, left, right, front, back, bottom...) in this application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0042] Embodiment

[0043] This embodiment provides a new type of low-cab electric power steering gear. The electric power steering gear can be driven into an underground garage to achieve a low-cab layout. On the premise of ensuring the vehicle's human-machine space and passing performance, it not only realizes the compression of the structural space of the electric power steering gear to meet the low-cab layout, but also reduces the part cost and maintenance convenience due to the optimization of the electronic control logic and mechanical structure.

[0044] As Figure 1 shown, this embodiment provides a new type of low-cab electric steering gear, which includes: a boost motor, an input shaft 1, an upper cover sealing ring 2, an upper cover bearing 3, an upper cover 4, a worm gear 5, a worm 6, a lower-end worm gear, a housing 7, a sealing ring 8, a retaining ring 9, a screw rod upper-end bearing 10, an output shaft 11, a screw rod lower-end bearing 12, and an oil seal 13.

[0045] In terms of the connection structure of the boost motor, the boost motor is fixedly connected to the housing 7 by bolt connection. The output end of the boost motor is connected to the input shaft 1 through the worm 6 and the worm gear 5. The settings of the worm 6 and the worm gear 5 can amplify and transmit the boost to the input shaft 1.

[0046] The EPS controller is used to control the boost motor to output steering boost according to the angle information and torque information transmitted by the steering wheel. The control logic of the boost motor is described as follows. The external steering wheel angle and torque sensors are integrated on the steering column. When the driver turns the steering wheel, after the external steering wheel angle and torque sensors collect the angle and torque changes on the steering wheel, they send the sensor signals to the EPS controller for analysis and processing through the vehicle CAN communication network, and control the boost motor to rotate and output steering boost.

[0047] In terms of the connection structure of the input shaft 1, the input shaft 1 is fixed to the housing 7 through the screw rod upper-end bearing 10, the screw rod lower-end bearing 12, and is connected to the boost motor through the worm 6 and the worm gear 5 at one end. The other end of the input shaft 1 is connected to the output shaft 11 through the lower-end worm gear.

[0048] It should be noted that the lower-end worm gear can achieve a technical effect similar to that of the worm 6 and the worm gear 5, so that the boost received by the input shaft 1 can be amplified again by the lower-end worm gear and transmitted to the output shaft 11. The input shaft 1 and the output shaft 11 are directly connected through the lower-end worm gear structure to achieve linkage. This feature can replace the ball screw structure by the rotation of the worm gear structure, effectively saving the space reserved for the up and down movement of the ball nut.

[0049] In this embodiment, to ensure the oil seal effect, a first oil seal part, a second oil seal part, and a third oil seal part are provided, and an oil seal 13 is provided at the lower end of the housing 7. In terms of the design of the first oil seal part, the screw rod upper-end bearing 10 is threadedly connected to the retaining ring 9 and the housing 7. The retaining ring 9 forms the first oil seal part at the upper part of the lower cavity of the housing 7 through the sealing ring 8 and the input shaft 1.

[0050] In terms of the design of the second oil seal part, the upper cover 4 is fixedly connected to the housing 7 by bolt connection, and at the same time, the upper end of the input shaft 1 is fixed by clearance fit through the upper cover bearing 3, and the second oil seal part at the upper part of the lower cavity of the housing 7 is formed through the sealing ring 2.

[0051] Regarding the design of the third oil seal part, an O-ring is provided between the upper cover 4 and the housing 7 to form the third oil seal part.

[0052] The EPS steering assist transmission path of this embodiment is described in detail below, as Figure 2 shown.

[0053] The externally mounted steering wheel angle sensor and the steering wheel torque sensor are integrated on the steering column or the steering wheel. When the driver turns the steering wheel, after the externally mounted steering wheel angle and torque sensors collect the angle and torque changes on the steering wheel, the sensor signals are sent to the EPS controller for analysis and processing through the vehicle CAN communication network via the first connector. The battery supplies power to the EPS controller through the second connector. The EPS controller controls the power assist motor to rotate and output steering assist. The steering assist is amplified by the worm gear 5 and the worm 6 and then transmitted to the input shaft 1, and then amplified again by the lower worm gear and worm, and output to the output shaft 11, thereby realizing the steering assist. In the above control logic, a separate externally mounted angle-torque sensor can further effectively reduce the space at the upper end of the EPS.

[0054] In order to achieve a low cab layout and enable the vehicle to drive into an underground garage, the electric steering gear in this embodiment innovatively moves the angle-torque sensor as a separate component to the upper end of the steering column and changes the original ball screw structure to a direct connection with a worm gear structure. This not only realizes the compression of the structural space of the electric steering gear to meet the low cab layout, but also reduces the part cost and improves the maintenance convenience due to the optimization of the electronic control logic and mechanical structure.

[0055] The specific embodiments of the present invention have been described above. Through the above description, relevant staff can make various changes and modifications within the scope not deviating from the technical idea of this invention.

Claims

1. A low cab electric steering gear, characterized in that, Comprising: An assist motor, an EPS controller, an input shaft (1), an upper cover bearing (3), an upper cover (4), a worm gear (5), a worm (6), a lower end worm gear, a housing (7), an upper bearing of the lead screw (10), an output shaft (11), a lower bearing of the lead screw (12), an oil seal (13); The assist motor is fixedly connected to the housing (7); the output end of the assist motor is connected to the input shaft (1) through the worm (6) and the worm gear (5); The EPS controller is used to control the assist motor to output steering assist according to the angle information and torque information transmitted by the steering wheel; The input shaft (1) is fixed by the upper bearing of the lead screw (10), the lower bearing of the lead screw (12) and the housing (7); the input shaft (1) is connected to the output shaft (11) through the lower end worm gear; A first oil seal part is provided at the upper bearing of the lead screw (10) in the upper cavity of the lower part of the housing (7); an oil seal (13) is further provided at the lower end of the housing (7); The upper cover (4) is fixedly connected to the housing (7) by bolt connection, and a second oil seal part is provided at the upper cover (4).

2. The low-cab electric steering gear according to claim 1, characterized in that, Also includes a sealing ring (8), a retaining ring (9); The upper bearing of the lead screw (10) is threadedly connected to the retaining ring (9) and the housing (7); the retaining ring (9) forms a first oil seal part in the upper cavity of the lower part of the housing (7) through the sealing ring (8) and the input shaft (1).

3. The low-cab electric steering gear according to claim 1, characterized in that, Also includes an upper cover sealing ring (2); The upper cover sealing ring (2) fixes the upper end of the input shaft (1) through clearance fit with the upper cover bearing (3), and forms a second oil seal part in the upper cavity of the lower part of the housing (7).

4. A low-cab electric steering gear according to claim 1, characterized in that, A third oil seal part is formed between the upper cover (4) and the housing (7) through an O-ring.

5. A low-cab electric steering gear according to claim 1, characterized in that, Also comprising: A first plug-in connector, a second plug-in connector; The angle information and torque information of the steering wheel are transmitted to the EPS controller through the vehicle CAN communication network, and the sensor signals are sent to the EPS controller through the first plug-in connector; The battery supplies power to the EPS controller through the second plug-in connector.

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