Screw nut centering structure

Abstract

This utility model discloses a screw-nut centering structure, including a screw structure, a bearing, and a steering gear housing. The screw structure includes a screw, a screw nut, a first connecting rod, and a second connecting rod. The screw nut is meshed with the screw. One end of the screw is connected to the first connecting rod, and the other end is connected to the second connecting rod. The screw structure is located inside the steering gear housing. The screw nut is mounted inside the steering gear housing via the bearing. The outer circumference of the screw nut is interference-fitted with the inner ring of the bearing. The first connecting rod and the second connecting rod are coaxially connected to the steering gear housing. This structure achieves centerline alignment of the screw and screw nut in a low-cost, indirect manner, and improves the working efficiency of the screw and screw nut. This structure can be used simultaneously in a front wheel steering system with screw and nut meshing.

Description

Technical Field

[0001] This utility model relates to vehicle steering systems, and in particular to a screw nut centering structure for rear wheel steering of a vehicle. Background Technology

[0002] In rear-wheel steering systems, mechanical transmission efficiency is a crucial issue. Higher mechanical transmission efficiency means less motor output power is required for the same rack force, resulting in lower costs and energy consumption. However, the mechanical transmission efficiency of rear-wheel steering is closely related to the engagement state of the lead screw and nut in the steering system. High coincidence between the centerlines of the lead screw and nut leads to higher mechanical transmission efficiency. However, for a three-section lead screw structure—consisting of the lead screw body and two connecting rods—it's difficult for the centerlines of the lead screw and nut to coincide. This leads to lower mechanical transmission efficiency and wasted energy when the lead screw and nut are engaged. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a screw and nut centering structure, which can solve the problem that the center lines of the screw and nut do not coincide when they are engaged in a three-section screw structure.

[0004] To solve the above problems, the present invention provides a lead screw and nut centering structure, including a lead screw structure, a bearing, and a steering gear housing. The lead screw structure includes a lead screw, a lead screw nut, a first connecting rod, and a second connecting rod. The lead screw nut is meshed with the lead screw. One end of the lead screw is connected to the first connecting rod, and the other end is connected to the second connecting rod. The lead screw structure is located inside the steering gear housing. The lead screw nut is installed inside the steering gear housing through the bearing. The outer circumference of the lead screw nut is interference-fitted with the inner ring of the bearing. The first connecting rod and the second connecting rod are coaxially connected to the steering gear housing.

[0005] Preferably, a first bushing is installed between the first connecting rod and the steering gear housing.

[0006] Preferably, a second bushing is installed between the second connecting rod and the steering gear housing.

[0007] Preferably, one end of the lead screw engages with the first connecting rod via a conical or cylindrical surface, and the other end engages with the second connecting rod via a conical or cylindrical surface.

[0008] Preferably, one end of the lead screw engages with one of the first connecting rod and the second connecting rod via an end face, and the other end of the lead screw engages with the other of the first connecting rod and the second connecting rod via a cylindrical surface.

[0009] Preferably, the lead screw includes a first connecting section, a smooth rod section, a second threaded section, and a second connecting section connected in sequence. The end of the first connecting rod forms a first inner cavity into which the first connecting section extends, and the end of the second connecting rod forms a second inner cavity into which the second connecting section extends. The lead screw nut is sleeved on the second threaded section.

[0010] Preferably, the outer peripheral surface of the end of the first connecting segment is formed with an external thread, the inner wall of the first inner cavity is formed with an internal thread that matches the external thread of the first connecting segment, the outer peripheral surface of the second connecting segment is formed with an external thread, and the inner wall of the second inner cavity is formed with an internal thread that matches the external thread of the second connecting segment.

[0011] Preferably, the steering gear housing has a mounting cavity, and the lead screw nut and the bearing are located in the mounting cavity.

[0012] Furthermore, the outer periphery of the lead screw nut is interference-fitted with the inner wall of the pulley.

[0013] Furthermore, the pulley is installed inside the mounting cavity and abuts against the bearing.

[0014] Compared with the prior art, the technical effects that this utility model can achieve are:

[0015] 1) The lead screw nut of this utility model is supported by a bearing fixedly installed in the steering gear housing, so that the center line of the lead screw nut coincides with the center line of the steering gear housing;

[0016] The two connecting rods are connected to the steering gear housing through bushings, so that the center lines of the two connecting rods coincide with the center line of the steering gear housing. At the same time, the two ends of the lead screw are connected to the two connecting rods through conical or cylindrical surfaces, ensuring that the center lines of the lead screw and the two connecting rods coincide, thereby indirectly ensuring that the center line of the lead screw coincides with the center line of the steering gear housing.

[0017] This utility model utilizes two connecting rods and a steering gear housing. The centerline of the lead screw is indirectly aligned with the centerline of the steering gear housing by aligning the two connecting rods with the centerline of the steering gear housing and by aligning the two connecting rods with the centerline of the lead screw. At the same time, the bearing is used to ensure that the centerline of the lead screw nut is aligned with the centerline of the steering gear housing, thus ensuring that the centerline of the lead screw is aligned with the centerline of the lead screw nut.

[0018] 2) This utility model achieves the alignment of the center lines of the lead screw and the lead screw nut in a low-cost manner, and improves the working efficiency of the lead screw and the lead screw nut. This structure can be used simultaneously in the front wheel steering system where the lead screw and nut mesh. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the rear wheel steering system of this utility model;

[0020] Figure 2 This is a schematic diagram showing the fit between the first connecting rod and the housing of this utility model;

[0021] Figure 3 This is a schematic diagram showing the fit between the second connecting rod and the housing of this utility model;

[0022] Figure 4 This is a schematic diagram showing the cooperation between the first connecting rod, the second connecting rod, and the lead screw in the first embodiment of this utility model;

[0023] Figure 5 This is a schematic diagram of a partial engagement between the first connecting rod and the lead screw according to the first embodiment of the present invention.

[0024] Figure 6 This is a partial view of the engagement between the second connecting rod and the lead screw in the first embodiment of this utility model.

[0025] Figure 7 This is a schematic diagram showing the cooperation between the first connecting rod, the second connecting rod, and the lead screw in the second embodiment of this utility model;

[0026] Figure 8 This is a schematic diagram of a partial engagement between the first connecting rod and the lead screw in the second embodiment of this utility model.

[0027] The accompanying diagrams are labeled as follows:

[0028] 1 is a nut; 2 is a bearing; 3 is a housing; 4 is a pulley; 5 is a lead screw; 6 is a first connecting rod; 7 is a second connecting rod; 8 is a first bushing; 9 is a second bushing; 10 is a first mating surface; 11 is a second mating surface. Detailed Implementation

[0029] The embodiments of this utility model are described below with reference to the accompanying drawings and specific examples. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Specific details are set forth in the following description to provide a full understanding of this utility model; however, this utility model can also be implemented or applied through other different specific embodiments, and the details in this specification can also be based on different viewpoints and applications. Those skilled in the art can make various similar extensions and substitutions without departing from the spirit of this utility model.

[0030] The lead screw and nut centering structure of this utility model includes a lead screw structure, a bearing 2, and a steering gear housing 3, as shown below. Figure 1 As shown, the lead screw structure includes a lead screw 5, a lead screw nut 1, a first connecting rod 6, and a second connecting rod 7.

[0031] like Figure 1As shown, the lead screw nut 1 is meshed with the lead screw 5. One end of the lead screw 5 is connected to the first connecting rod 6, and the other end is connected to the second connecting rod 7. The lead screw structure is located inside the steering gear housing 3. The lead screw nut 1 is installed inside the steering gear housing 3 through the bearing 2. The outer circumference of the lead screw nut 1 is interference-fitted with the inner ring of the bearing 2. The first connecting rod 6 and the second connecting rod 7 are coaxially connected to the steering gear housing 3.

[0032] like Figure 2 As shown, a first bushing 8 is installed between the first connecting rod 6 and the steering gear housing 3.

[0033] like Figure 3 As shown, a second bushing 9 is installed between the second connecting rod 7 and the steering gear housing 3.

[0034] like Figure 4 As shown, one end of the lead screw 5 engages with the first connecting rod 6 via a conical or cylindrical surface, and the other end engages with the second connecting rod 7 via a conical or cylindrical surface.

[0035] like Figure 4 As shown, the lead screw 5 includes a first connecting section, a smooth rod section, a second threaded section, and a second connecting section connected in sequence. The end of the first connecting rod 6 forms a first inner cavity into which the first connecting section extends, and the end of the second connecting rod 7 forms a second inner cavity into which the second connecting section extends. The lead screw nut 1 is sleeved on the second threaded section.

[0036] One end of the lead screw 5 engages with the first connecting rod 6 via its end face, and the other end engages with the second connecting rod 7 via its cylindrical surface; or one end of the lead screw 5 engages with the first connecting rod 6 via its cylindrical surface, and the other end engages with the second connecting rod 7 via its end face.

[0037] The lead screw 5 engages with one of the second connecting rods 7, and the other end of the lead screw 5 engages with the first connecting rod 6 and the other of the second connecting rods via a cylindrical surface.

[0038] like Figure 5 , Figure 6 As shown, the outer peripheral surface of the end of the first connecting segment is formed with an external thread, the inner wall of the first inner cavity is formed with an internal thread that matches the external thread of the first connecting segment, the outer peripheral surface of the second connecting segment is formed with an external thread, and the inner wall of the second inner cavity is formed with an internal thread that matches the external thread of the second connecting segment.

[0039] The steering gear housing 3 has an installation cavity, and the lead screw nut 1 and the bearing 2 are located in the installation cavity.

[0040] like Figure 1 As shown, the steering gear housing includes a steering gear housing 3 and a steering gear end cover. A lead screw nut 1, a bearing 2, a lead screw 5, a first connecting rod 6, and a second connecting rod 7 are located in the mounting cavity formed by the steering gear housing 3 and the steering gear end cover. The lead screw 5 is located in the middle of the mounting cavity, with its left end connected to the first connecting rod 6 and its right end connected to the second connecting rod 7. The lead screw nut 1 is located on the second threaded section of the lead screw 5.

[0041] The outer peripheral wall of the lead screw nut 1 is interference-fitted with the inner ring of the bearing 2, and the bearing 2 is installed inside the steering gear housing 3. The outer peripheral wall of the lead screw nut 1 is interference-fitted with the inner wall of the pulley 4, which is powered by a motor ( Figure 1 (Not shown in the image) drives the pulley. The pulley 4 is installed inside the mounting cavity and abuts against the bearing 2. Figure 1 As shown, the right side of bearing 2 abuts against the steering gear end cover, and the left side abuts against the right side of pulley 4. The left side of pulley 4 abuts against steering gear housing 3.

[0042] Since the lead screw nut 1 is fixedly connected to the pulley 4, when the motor drives the pulley 4 to rotate, the lead screw nut will inevitably be driven to rotate as well. Because the lead screw nut 1 and the lead screw 5 are connected by threaded engagement, and the lead screw nut 1 is fixedly connected to the bearing 2, the rotation of the lead screw nut 1 will cause the lead screw 5 to move axially left and right in the straight direction. Simultaneously, the lead screw 5 is connected to the rear wheel steering mechanism of the vehicle through the first connecting rod 6 and the second connecting rod 7, thus enabling the rear wheels to rotate.

[0043] To ensure full engagement between the lead screw nut 1 and the lead screw 5, the centerlines of the lead screw nut 1 and the lead screw 5 need to be coaxial. In this invention, to address the coaxiality issue of the lead screw nut 1 and the lead screw 5, the lead screw nut 1 is supported in the steering gear housing 3 by a bearing 2. This ensures that the centerline of the lead screw nut is coaxial with the centerline of the mounting cavity of the steering gear housing 3. Figure 1 As shown.

[0044] At the same time, such as Figure 2 As shown, the first connecting rod 6 engages with the steering gear housing 3 via the first bushing 8, ensuring that the centerline of the first connecting rod 6 coincides with the centerline of the mounting cavity of the steering gear housing 3. Similarly, as... Figure 3 As shown, the second connecting rod is engaged with the steering gear housing 3 through the second bushing 9, which ensures that the center line of the second connecting rod 7 coincides with the center line of the mounting cavity of the steering gear housing 3.

[0045] like Figure 4 and Figure 5As shown, the external thread at the left end of the lead screw 5 is threadedly connected to the internal thread in the first inner cavity at the right end of the first connecting rod 6. Simultaneously, the lead screw 5 and the first connecting rod 6 engage through the first mating surface 10, thus ensuring that the centerline of the lead screw 5 coincides with the centerline of the first connecting rod 6. Similarly, as... Figure 4 and Figure 6 As shown, the external thread at the right end of the lead screw 5 and the internal thread in the second inner cavity at the left end of the second connecting rod 7 are threaded together. At the same time, the lead screw 5 and the second connecting rod 7 are engaged through the second mating surface 11, which ensures that the center line of the lead screw 5 and the center line of the second connecting rod 7 coincide.

[0046] Ultimately, since the first connecting rod 6 and the second connecting rod 7 coincide with the center line of the mounting cavity of the steering gear housing 3, and the first connecting rod 6 and the second connecting rod 7 also coincide with the center line of the lead screw 5, the center line of the lead screw 5 and the center line of the mounting cavity of the steering gear housing 3 are indirectly aligned. Simultaneously, the center line of the lead screw nut 1 also coincides with the center line of the mounting cavity of the steering gear housing 3, thus achieving coaxial alignment between the center line of the lead screw 5 and the center line of the lead screw nut 1.

[0047] In the first embodiment of this utility model, as Figure 4 , Figure 5 and Figure 6 As shown, the first mating surface 10 is a conical surface, and the second mating surface 11 is a cylindrical surface. The lead screw 5 mates with the first connecting rod 6 through the conical surface and with the second connecting rod 7 through the cylindrical surface, thus aligning the center lines of the lead screw 5 with those of the first and second connecting rods 6 and 7. However, this embodiment is not limited to this. The first connecting rod 6 can also mate with the lead screw 5 through a cylindrical surface, while the second connecting rod 7 mates with the lead screw 5 through a conical surface. Alternatively, the first connecting rod 6 can mate with the lead screw 5 through a conical surface, and the second connecting rod 7 can also mate with the lead screw 5 through a conical surface. Furthermore, the first connecting rod 6 can mate with the lead screw 5 through a cylindrical surface, and the second connecting rod 7 can also mate with the lead screw 5 through a cylindrical surface.

[0048] In the second embodiment of this utility model, as Figure 7 , Figure 8 and Figure 6As shown, the second mating surface 11 is a cylindrical surface, and the first mating surface 10 is an end face. The right end of the lead screw 5 mates with the second connecting rod 7 through the cylindrical surface, thus ensuring that the center lines of the lead screw 5 and the second connecting rod 7 coincide. Since the center line of the second connecting rod 7 coincides with the center line of the mounting cavity of the steering gear housing 3, it indirectly ensures that the axis of the lead screw 5 coincides with the center line of the mounting cavity of the steering gear housing 3, thus playing a positioning role. At the same time, the left end of the lead screw 5 mates with the first connecting rod 6 through the end face. Since the end face (stepped surface) is perpendicular to the axis of the lead screw 5 and the axis of the first connecting rod 6, the axis of the lead screw 5 is parallel to the axis of the first connecting rod 6, indirectly ensuring that the axis of the lead screw 5 is parallel to the center line of the mounting cavity of the steering gear housing 3, thus playing an auxiliary positioning role and avoiding over-constraint problems. Of course, this embodiment is not limited to this; the first connecting rod 6 can also mate with the lead screw 5 through the cylindrical surface, and the second connecting rod 7 can mate with the lead screw 5 through the end face.

[0049] This invention achieves the alignment of the center lines of the lead screw and lead screw nut through a low-cost, indirect method (lead screw nut – bearing – steering gear housing – first connecting rod and second connecting rod – lead screw), and improves the working efficiency of the lead screw and lead screw nut. This structure can be used simultaneously in front wheel steering systems where the lead screw and nut mesh.

[0050] The present invention has been described in detail above through specific embodiments. These embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to the above-described implementation methods. Equivalent substitutions and improvements made by those skilled in the art without departing from the principles of the present invention should be considered within the scope of the technology protected by the present invention.

Claims

1. A lead screw nut centering structure, characterized by, The system includes a lead screw structure, a bearing, and a steering gear housing. The lead screw structure includes a lead screw, a lead screw nut, a first connecting rod, and a second connecting rod. The lead screw nut is engaged with the lead screw. One end of the lead screw is connected to the first connecting rod, and the other end is connected to the second connecting rod. The lead screw structure is located inside the steering gear housing. The lead screw nut is mounted inside the steering gear housing via the bearing. The outer circumference of the lead screw nut is interference-fitted with the inner ring of the bearing. The first connecting rod and the second connecting rod are coaxially connected to the steering gear housing.

2. The lead screw and nut alignment structure according to claim 1, characterized in that, A first bushing is installed between the first connecting rod and the steering gear housing.

3. The lead screw and nut alignment structure according to claim 1, characterized in that, A second bushing is installed between the second connecting rod and the steering gear housing.

4. The lead screw and nut alignment structure according to claim 1, characterized in that, One end of the lead screw engages with the first connecting rod via a conical or cylindrical surface, and the other end engages with the second connecting rod via a conical or cylindrical surface.

5. The lead screw and nut alignment structure according to claim 1, characterized in that, One end of the lead screw engages with one of the first connecting rod and the second connecting rod via an end face, and the other end of the lead screw engages with the other of the first connecting rod and the second connecting rod via a cylindrical surface.

6. The lead screw and nut alignment structure according to claim 1, characterized in that, The lead screw includes a first connecting section, a smooth rod section, a second threaded section, and a second connecting section connected in sequence. The end of the first connecting rod has a first inner cavity into which the first connecting section extends, and the end of the second connecting rod has a second inner cavity into which the second connecting section extends. The lead screw nut is sleeved on the second threaded section.

7. The lead screw and nut alignment structure according to claim 6, characterized in that, The outer peripheral surface of the end of the first connecting segment is formed with an external thread, and the inner wall of the first inner cavity is formed with an internal thread that matches the external thread of the first connecting segment. The outer peripheral surface of the second connecting segment is formed with an external thread, and the inner wall of the second inner cavity is formed with an internal thread that matches the external thread of the second connecting segment.

8. The lead screw and nut centering structure according to claim 1, characterized in that, The steering gear housing has a mounting cavity, and the lead screw nut and the bearing are located in the mounting cavity.

9. The lead screw and nut alignment structure according to claim 8, characterized in that, The outer periphery of the lead screw nut is interference-fitted with the inner wall of the pulley.

10. The lead screw and nut alignment structure according to claim 9, characterized in that, The pulley is installed inside the mounting cavity and abuts against the bearing.

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