A structure of an external circulation ball screw pair used in automotive steering systems

Abstract

This application provides a structure for an external circulation ball screw assembly used in an automotive steering system, comprising: a screw; a nut disposed on the periphery of the screw, and a raceway formed between the periphery of the screw and the inner diameter of the nut, wherein a plurality of steel balls are disposed within the raceway; a first guide tube and a second guide tube respectively mounted above the nut, wherein guide tube tongues are provided at the openings of the first and second guide tubes located inside the nut; and a guide tube clamp for fixing the first and second guide tubes is mounted on the upper side of the nut. By fully utilizing the empty raceway to fill the steel balls through the irregular guide tube design, the load-bearing capacity of the screw is improved, better adapting to the usage requirements of automotive steering systems under complex working conditions, effectively improving the stability and reliability of vehicle steering. The intersecting guide tube design, combined with three-dimensional simulation to optimize the fit dimensions, reduces failures such as guide tube bursting and jamming, lowers maintenance costs and vehicle failure risks, and extends the service life of the steering system.

Description

Technical Field

[0001] This utility model relates to the field of automotive steering system technology, and more specifically, to a structure of an external circulation ball screw pair applied to an automotive steering gear. Background Technology

[0002] In the automotive manufacturing industry, the steering gear is a key component of the automotive steering system, and its performance directly affects the vehicle's handling stability and driving safety. Due to its high transmission efficiency, the ball screw pair is widely used in automotive recirculating ball steering gears.

[0003] On the one hand, to optimize the driving experience, improve the feel of the steering force, and adapt to the steering requirements under complex road conditions, higher requirements are placed on the load-bearing capacity of the ball screw structure of the steering gear. On the other hand, the automotive market is highly competitive, and while ensuring the strength and service life of the steering gear, it is necessary to strictly control costs. This requires the steering gear structure to be more compact and lower in cost. However, the existing ball screw pair structure has obvious shortcomings, such as the load-bearing capacity being unable to meet the new requirements, defects in the fit between the guide and the raceway, which lead to the guide being prone to bursting and jamming, and high material consumption under the same load-bearing capacity, making it difficult to optimize the structural dimensions.

[0004] Therefore, we have made improvements to this and proposed a structure for an external circulation ball screw pair applied to automotive steering systems. Summary of the Invention

[0005] The purpose of this utility model is to address the significant shortcomings of existing ball screw assembly structures, such as insufficient load-bearing capacity to meet new requirements, defects in the fit between the guide tube and the raceway leading to easy bursting and jamming of the guide tube, high material consumption under the same load-bearing capacity, and difficulty in optimizing structural dimensions.

[0006] To achieve the above-mentioned objectives, this utility model provides the following technical solution:

[0007] A structure for external circulation ball screw pairs applied to automotive steering systems to improve the aforementioned problems.

[0008] The application is as follows:

[0009] The device includes: a screw; a nut disposed on the periphery of the screw, and a raceway disposed on the periphery of the screw and the inner diameter of the nut, wherein a plurality of steel balls are disposed within the raceway; a first guide tube and a second guide tube are respectively installed above the nut, and guide tube tongues are provided at the openings of the first and second guide tubes located inside the nut, the guide tube tongues cooperating with the steel balls; a guide tube clamp for fixing the first and second guide tubes is installed on the upper side of the nut; the screw, nut, steel balls, first guide tube and second guide tube are combined to form a lead screw assembly.

[0010] In a preferred embodiment of the external circulation ball screw assembly for automotive steering systems provided by this utility model, the two ends of the screw are supported by bearings, and the screw can rotate but cannot move axially.

[0011] As a preferred embodiment of the external circulation ball screw assembly for automotive steering systems provided by this utility model, the screw assembly has two independent circulation structures, one of which is one and a half turns and is formed by the first guide tube, and the other is two and a half turns and is formed by the second guide tube. The steel balls in the two circulation structures do not affect each other.

[0012] In a preferred embodiment of the external circulation ball screw pair for automotive steering systems provided by this utility model, the first and second conduits function as a reverser, and the steel balls return to the raceway through the conduit hole when passing through the conduit tongue.

[0013] In a preferred embodiment of the structure of the external circulation ball screw pair for automotive steering systems provided by this utility model, the first conduit and the second conduit are irregularly shaped conduits, and the steel balls fill the empty ring between the first conduit and the second conduit.

[0014] As a preferred embodiment of the external circulation ball screw pair for automotive steering systems provided by this utility model, the first and second guide tubes adopt an intersecting guide tube design, and the fit dimensions between the guide tube tongue and the raceway are optimized through three-dimensional simulation. Under the same raceway mid-diameter, the thickness of the nut is less than that of the conventional structure.

[0015] As a preferred embodiment of the structure of the external circulation ball screw pair for automotive steering systems provided by this utility model, one end of the screw is provided with a spline, the bottom of the nut is provided with a rack, a plurality of fastening screws are threaded between the guide clamp and the nut, and a spring washer is provided between the fastening screws and the guide clamp.

[0016] As a preferred embodiment of the external circulation ball screw pair for automotive steering provided by this utility model, when the spline of the screw inputs torque, the screw transmits force to the raceway of the nut through the steel balls in its raceway, causing the nut to move axially, and the rack on the nut moves axially together to transmit force to the gear.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] This utility model provides a structure for an external circulation ball screw assembly applied to an automotive steering gear, comprising: a screw; a nut disposed on the periphery of the screw, and a raceway formed on the periphery of the screw and the inner diameter of the nut, wherein a plurality of steel balls are disposed within the raceway; a first guide tube and a second guide tube respectively mounted above the nut, wherein the openings of the first and second guide tubes located inside the nut are provided with guide tube tongues, the guide tube tongues engaging with the steel balls; a guide tube clamp for fixing the first and second guide tubes is mounted on the upper side of the nut; the screw, nut, steel balls, first guide tube, and second guide tube are combined to form a screw assembly. By employing an irregularly shaped guide tube design, and utilizing the empty space in the middle to fill the steel balls, the contact area between the balls and the raceway and the number of bearing points are effectively increased. Under the same working conditions, compared with the traditional structure, the load-bearing capacity of the ball screw is significantly improved, which can better meet the usage requirements of automotive steering systems under complex road conditions and high loads, improve the stability and reliability of vehicle steering, and reduce the risk of component damage due to insufficient load-bearing capacity. The first and second guide tubes adopt an intersecting guide tube design, and the matching dimensions of the guide tongue and raceway are optimized by three-dimensional simulation, which precisely controls the movement trajectory and force of the steel ball in the reverse process. This reduces the problems of guide tube bursting and jamming caused by interference between the guide tongue and raceway and improper force points of steel ball impacting the tongue in the traditional structure, reduces the frequency of equipment failure, extends the service life of the ball screw pair, reduces maintenance costs and reduces safety hazards caused by steering failures in vehicles. Under the condition of achieving the same raceway pitch diameter, the thickness of the nut is smaller than that of the previous structure. This means that the amount of nut material used in the production process is reduced, directly reducing the raw material cost. At the same time, the reduction in nut size allows the corresponding reduction in the size of the mating hand housing and other components, further saving material and processing costs and improving the market competitiveness of the product. Attached Figure Description

[0019] Figure 1 This is a structural schematic diagram of the lead screw assembly provided in this application;

[0020] Figure 2 This is a schematic diagram of the internal structure of the nut provided in this application;

[0021] Figure 3 This is a schematic diagram of the structure of the nut provided in this application;

[0022] Figure 4 This is a schematic diagram of the connection between the guide clamp and the nut provided in this application.

[0023] The image shows:

[0024] 1. Screw; 2. Nut; 3. Raceway; 4. Steel ball; 5. First guide tube; 6. Second guide tube; 7. Guide tube clamp; 8. Spline; 9. Rack; 10. Guide tube clamp; 11. Fastening screw; 12. Spring washer. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model.

[0026] Therefore, the following detailed description of the embodiments of this utility model is not intended to limit the scope of the claimed utility model, but merely to illustrate some embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0027] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] In the description of this utility model, it should be noted that the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0031] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0033] Please refer to Figure 1-4A structure for an external circulation ball screw assembly used in an automotive steering system includes: a screw 1; a nut 2 disposed on the periphery of the screw 1, and a raceway 3 disposed on the periphery of the screw 1 and the inner diameter of the nut 2, with a plurality of steel balls 4 disposed within the raceway 3; a first guide tube 5 and a second guide tube 6 respectively mounted above the nut 2, and guide tube tongues 7 disposed at the openings of the first guide tube 5 and the second guide tube 6 located inside the nut 2, the guide tube tongues 7 engaging with the steel balls 4; a guide tube clamp 10 for fixing the first guide tube 5 and the second guide tube 6 mounted on the upper side of the nut 2; the screw 1, the nut 2, the steel balls 4, the first guide tube 5 and the second guide tube 6 are combined to form a screw assembly.

[0034] Please refer to Figure 2-3 The screw 1 is supported by bearings at both ends. The screw 1 can rotate but cannot move axially. The screw assembly has two independent circulation structures. One circulation is one and a half turns, formed by the first guide tube 5, and the other circulation is two and a half turns, formed by the second guide tube 6. The steel balls 4 in the two circulation structures do not affect each other. The first guide tube 5 and the second guide tube 6 act as a reversing mechanism. When the steel ball 4 passes through the guide tongue 7, it returns to the raceway 3 through the guide hole. The first guide tube 5 and the second guide tube 6 are irregularly shaped guide tubes. The steel ball 4 fills the empty loop between the first guide tube 5 and the second guide tube 6. The first guide tube 5 and the second guide tube 6 adopt an intersecting guide tube design, and the fit dimensions between the guide tongue 7 and the raceway 3 have been optimized through three-dimensional simulation. Under the same raceway 3 mean diameter, the thickness of the nut 2 is smaller than that of the previous structure. When torque is input at the spline 8 of the screw 1, the screw 1 begins to rotate. Because the screw 1 is supported by bearings at both ends... The support can only rotate and cannot move axially. When it rotates, the steel balls 4 in the raceway 3 roll accordingly. During the rolling process, the steel balls 4 convert the rotation of the screw 1 into movement along the raceway 3, and at the same time transmit the force to the raceway 3 of the nut 2. Under the action of the force, the nut 2 moves along the axial direction of the screw 1. The bottom of the nut 2 is equipped with a rack 9. When the nut 2 moves axially, the rack 9 also moves axially synchronously. The rack 9 cooperates with the gear. The axial movement of the rack 9 drives the gear to rotate, thereby realizing the power transmission and steering action of the car steering system. During the circulation of the steel balls 4, the first guide tube 5 and the second guide tube 6 play a key role as a reverser. In the two independent circulation structures, when the steel balls 4 pass through the guide tongue 7 of the first guide tube 5 and the second guide tube 6, they will return to the raceway 3 through the guide hole, so that the steel balls 4 can continuously circulate between the raceway 3 and the guide tubes 5 and 6, ensuring the stable transmission of the screw pair.

[0035] Please refer to Figure 4One end of the screw 1 is provided with a spline 8, and the bottom of the nut 2 is equipped with a rack 9. Multiple fastening screws 11 are threaded between the guide clamp 10 and the nut 2. A spring washer 12 is provided between the fastening screw 11 and the guide clamp 10. When the spline 8 of the screw 1 is input with torque, the screw 1 transmits the force to the raceway 3 of the nut 2 through the steel ball 4 in its raceway 3, causing the nut 2 to move axially. The rack 9 on the nut 2 moves axially along with it, transmitting the force to the gear. The guide clamp 10 is used to compact the first guide 5 and the second guide 6. During the operation, it is necessary to ensure that the first guide 5 and the second guide 6 do not wobble up, down, left, or right. At the same time, it is important to ensure that the guide clamp 10 does not extend beyond the end face of the turning nut 2.

[0036] The above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, the present utility model is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present utility model, and all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present utility model.

Claims

1. A structure of an outer circulation ball screw pair applied to a steering gear of an automobile, characterized by, include: Screw (1); The screw (1) is provided with a nut (2) on its periphery, and a raceway (3) is provided on the periphery of the screw (1) and the inner diameter of the nut (2), and a number of steel balls (4) are provided in the raceway (3). A first conduit (5) and a second conduit (6) are respectively installed above the nut (2). The first conduit (5) and the second conduit (6) are provided with conduit tongues (7) at the openings inside the nut (2). The conduit tongues (7) cooperate with the steel ball (4). The upper side of the nut (2) is fitted with a catheter clamp (10) for fixing the first catheter (5) and the second catheter (6). The screw (1), nut (2), steel ball (4), first guide tube (5) and second guide tube (6) are combined to form a screw assembly.

2. The structure of an external circulation ball screw pair applied to an automotive steering system according to claim 1, characterized in that, The screw (1) is supported at both ends by bearings. The screw (1) can rotate but cannot move axially.

3. The structure of an external circulation ball screw pair applied to an automotive steering system according to claim 1, characterized in that, The lead screw assembly has two independent circulation structures. One circulation is one and a half turns, which is formed by the first guide tube (5). The other circulation is two and a half turns, which is formed by the second guide tube (6). The steel balls (4) in the two circulation structures do not affect each other.

4. The structure of an external circulation ball screw pair applied to an automotive steering system according to claim 1, characterized in that, The first conduit (5) and the second conduit (6) act as a reverser, and the steel ball (4) returns to the raceway (3) through the conduit hole when it passes through the conduit tongue (7).

5. The structure of an external circulation ball screw pair applied to an automotive steering system according to claim 1, characterized in that, The steel ball (4) fills the empty ring between the first conduit (5) and the second conduit (6).

6. The structure of an external circulation ball screw pair applied to an automotive steering system according to claim 1, characterized in that, The first catheter (5) and the second catheter (6) adopt an intersecting catheter design.

7. The structure of an external circulation ball screw pair applied to an automotive steering system according to claim 1, characterized in that, One end of the screw (1) is provided with a spline (8), the bottom of the nut (2) is provided with a rack (9), a plurality of fastening screws (11) are threaded between the guide clamp (10) and the nut (2), and a spring washer (12) is provided between the fastening screw (11) and the guide clamp (10).

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