WO2024041113A1 - Universal swinging-type recirculating ball nut mechanism of electric power steering machine - Google Patents

Abstract

Provided in the present invention is a universal swinging-type recirculating ball nut mechanism of an electric power steering machine. The mechanism comprises a recirculating ball nut, a ball bearing and a belt pulley; one side of the outer edge of the recirculating ball nut is sleeved with a ball bearing, and the other side is sleeved with the belt pulley; the inner ring of the recirculating ball bearing is connected to the belt pulley through threads; cylindrical pins are embedded between the recirculating ball nut and the belt pulley, the outer surfaces of the cylindrical pins being fitted to notches of the belt pulley; and a universal joint ring is sleeved on the recirculating ball nut. The inner side surface of the universal joint ring has a curved surface structure, and the curved surface structure is fitted to the spherical curved surface of the recirculating ball nut, such that a radial load and a bending moment of a lead screw will not be directly transmitted to the inner ring of the ball bearing, and the relative position of the inner ring of the ball bearing is not affected by an external radial load. Thus, the relative position of the belt pulley is also not affected, which ensures that the tension of a belt is kept constant all the time, thereby eradicating the slipping or tooth skipping phenomena of belts and improving the accuracy of steering systems.

Description

A universal swing recirculating ball nut mechanism for electronic power steering gear

This application claims priority from Chinese patent application 202211016519.X with a filing date of 2022/8/24. This application cites the full text of the above-mentioned Chinese patent application.

Technical field

The invention relates to the technical field of electronic power steering machines, and specifically relates to a universal swing-type recirculating ball nut mechanism of electronic power steering machines.

Background technique

Ball screw driven electronic power steering is a common form of electronic power steering at present. In order to fix the ball screw structure, a ball bearing is often required. In order to make the steering gear have high power assist accuracy, high operating efficiency and low noise, the ball bearing is often a four-point contact bearing, so the bearing will bear a huge load in the steering system. axial force. In order to make the steering gear low-cost and lightweight, it is often hoped that the bearing can achieve greater axial load-bearing capacity with smaller specifications.

In order for the ball screw to transmit power, a set of pulleys and toothed belts are often required to form a reduction mechanism. The larger pulley is often fixed on the recirculating ball nut through a rigid connection. In order to reduce the friction of the belt, the belt is often arranged on the pulley with a smaller tension.

Therefore, when the car passes over bumpy roads, the tires will produce a radial load on the screw, forming an additional bending moment on the screw. This bending moment will cause the recirculating ball nut to deform or warp, which will mainly cause problems. There are three points: (1) The bending moment will increase the stress on the recirculating ball nut and screw. In order to adapt to higher loads, the diameter of the ball screw must be increased simultaneously; (2) The radial force generated by the bending moment will is transmitted to the inner ring of the bearing, so the size of the bearing must also increase; (3) Due to the deformation or warping of the recirculating ball nut, the position of the pulley will inevitably jump, especially when the screw is subject to impact load, and The beating of the pulley will cause the belt to loosen, etc., resulting in the belt jumping or slipping, which will cause uneven moving force of the steering gear and affect the position accuracy of the steering.

In order to solve the above problems, in CN113382914 A, a ball screw transmission mechanism design of an electronic power steering system is disclosed. In this design, the recirculating ball nut is fixed in the pulley in the form of a universal joint. This joint structure is realized by a universal joint section fixed in the pulley and a spherical structure on the recirculating ball nut, which is characterized by the recirculating ball. The nut can rotate in any direction around an axis perpendicular to the screw axis, and the pulley is rigidly connected to the inner ring of the bearing and does not deflect with the recirculating ball nut.

In order for the pulley to transmit torque to the recirculating ball nut, this mechanism has a ring of tooth structures arranged inside the pulley and outside the recirculating ball nut. In order to make the teeth fit closely, a plastic tooth space is arranged between the two ring gears. ring. Since the structural cooperation of the entire circumferential tooth and the tooth requires the transmission of a large torque and the function of "the recirculating ball nut can rotate around an axis perpendicular to the screw axis", the plastic inter-tooth ring is in principle It is impossible to achieve a close fit with the teeth, so this structure will cause the steering gear to be noisy and have higher manufacturing costs.

At the same time, in order to realize the tight fit between the ring of the universal joint section and the recirculating ball nut, this structure is equipped with a set of annular element loading devices, and multiple spring elements are arranged circumferentially between the two loading elements. This loading scheme has a complex structure, and due to the limited layout space of the spring elements and the small size of the elements, it often can only provide a small loading force.

Contents of the invention

In order to overcome the shortcomings of the prior art, the present invention provides a universal swing-type recirculating ball nut mechanism for an electronic power steering gear. This device can prevent the radial load and bending moment of the screw from being directly transmitted to the inner ring of the ball bearing. , the relative position of the inner ring of the ball bearing will not be affected by the radial load from the outside, so that the relative position of the pulley will not be affected, which ensures that the tension of the belt remains unchanged, thereby eliminating the need for the belt to The occurrence of slippage or tooth skipping improves the accuracy of the steering system.

In order to achieve the above purpose, a universal swing recirculating ball nut mechanism of an electronic power steering machine is designed, which includes a recirculating ball nut, a ball bearing, and a pulley. The characteristic is that a ball bearing is located on the outer edge side of the recirculating ball nut. A pulley is set on the other side of the outer edge of the recirculating ball nut, and the end of the pulley is The edge is connected to the threaded locking ring through threads; a number of cylindrical pins are embedded between the recirculating ball nut and the pulley, and a ring is set on the outside of the cylindrical pin; between the recirculating ball nut and the threaded locking ring There is a spring element between them, and a universal joint ring is set on the recirculating ball nut between the cylindrical pin and the spring element.

There are at least two cylindrical pins, and the two cylindrical pins are respectively embedded in the upper end and lower end of the recirculating ball nut.

The outer surface of the recirculating ball nut is connected by a long cylindrical surface and a spherical curved surface. The middle part of the spherical curved surface of the recirculating ball nut is a short cylindrical surface. The upper and lower ends of the short cylindrical surface are respectively provided with round hole grooves. .

One end of the cylindrical pin is located in the circular hole groove of the recirculating ball nut, and one end of the cylindrical pin is connected with the circular hole groove with an interference fit; the other end of the cylindrical pin is located outside the recirculating ball nut, and the top of the cylindrical pin is provided with a limited Flange structure.

The inner surfaces of both ends of the pulley are respectively provided with internal threads, one side of the inside of the pulley is provided with a reduction surface, and the other side of the inside of the pulley is provided with an inner hole mating surface; the upper and lower ends of the inner side of the pulley are respectively provided with grooves. The position and size of the notch match the ring.

The spring element is a disc spring or a wave spring.

The inner surface of the universal joint ring has a curved surface structure, and the curved surface structure matches the spherical curved surface of the recirculating ball nut.

The other end of the ring and the cylindrical pin are connected with a clearance fit.

The inner ring of the ball bearing is provided with an inner ring. One end of the inner ring is located inside the ball bearing. The other end of the inner ring is connected to the internal thread of one end of the pulley through threads. The other end of the pulley is connected to the threaded locking ring through threads. .

Compared with the existing technology, the present invention provides a universal swing-type recirculating ball nut mechanism for an electronic power steering gear. This device can prevent the radial load and bending moment of the screw from being directly transmitted to the inner ring of the ball bearing. The relative position of the inner ring of the ball bearing will not be affected by external radial loads, so that the relative position of the pulley will not be affected, which ensures that the tension of the belt remains unchanged. This prevents the belt from slipping or skipping teeth and improves the accuracy of the steering system.

Description of drawings

Figure 1 is a schematic structural diagram of the present invention.

Figure 2 is a cross-sectional view of the structure of the present invention.

Figure 3 is a cross-sectional view along the line A-A in Figure 2 .

Figure 4 is an exploded view of the structure of the present invention.

Figure 5 is a schematic diagram of the structure of the recirculating ball nut.

Figure 6 is a schematic diagram of the pulley structure.

Figure 7 is a cross-sectional view taken along line B-B in Figure 6 .

Figure 8 is a schematic diagram of the swing principle of the present invention.

Detailed ways

Example 1

The present invention will be further described below based on the accompanying drawings.

As shown in Figures 1 to 8, a ball bearing 9 is set on one side of the outer edge of the recirculating ball nut 4, and a pulley 7 is set on the other side of the outer edge of the recirculating ball nut 4. The inner edge of the end of the pulley 7 is threaded Connect the threaded locking ring 1; a number of cylindrical pins 6 are embedded between the recirculating ball nut 4 and the pulley 7, and a ring 5 is set outside the cylindrical pin 6; the recirculating ball nut 4 and the thread There is a spring element 2 between the locking rings 1, and a universal joint ring 3 is set on the recirculating ball nut 4 between the cylindrical pin 6 and the spring element 2.

There are at least two cylindrical pins 6 , and the two cylindrical pins 6 are respectively embedded in the upper and lower ends of the recirculating ball nut 4 .

The outer surface of the recirculating ball nut 4 is connected by a long cylindrical surface 4-1 and a spherical curved surface 4-2. The middle part of the spherical curved surface 4-2 of the recirculating ball nut 4 is a short cylindrical surface 4-3, which is located in the short cylinder. The upper and lower ends of the surface 4-3 are respectively provided with circular hole grooves 4-4.

One end of the cylindrical pin 6 is located in the circular hole groove 4-4 of the recirculating ball nut 4, and one end of the cylindrical pin 6 The end and the circular hole groove 4-4 are connected with an interference fit; the other end of the cylindrical pin 6 is located outside the recirculating ball nut 4, and the top of the cylindrical pin 6 is provided with a limiting flange structure 6-1.

The inner surfaces of both ends of the pulley 7 are respectively provided with internal threads 7-2, one side inside the pulley 7 is provided with a reduction surface 7-3, and the other side inside the pulley 7 is provided with an inner hole mating surface 7-4; The upper end and lower end of the inner side are respectively provided with notches 7-1. The position and size of the notches 7-1 match the ring 5.

The spring element 2 is a disc spring or a wave spring.

The inner surface of the universal joint ring 3 is a curved surface structure 3-1, and the curved surface structure 3-1 matches the spherical curved surface 4-2 of the recirculating ball nut 4.

The other end of the ring 5 and the cylindrical pin 6 are connected with a clearance fit.

The inner ring of the ball bearing 9 is provided with an inner ring 8. One end of the inner ring 8 is located inside the ball bearing 9. The other end of the inner ring 8 is connected to the internal thread 7-2 on the inside of one end of the pulley 7 through threads. The other end of the pulley 7 passes through The thread is connected to the thread locking ring 1.

On the spherical curved surface 4-2 of the recirculating ball nut 4, two cylindrical pins 6 are arranged symmetrically up and down. These two cylindrical pins 6 can slide in the two notches 7-1 inside the pulley 7, and the recirculating ball nut 4 can rotate along the axis of the cylindrical pin 6 when the cylindrical pin 6 slides to any set position, thus forming a structure with the function of "the recirculating ball nut can rotate around an axis perpendicular to the screw axis".

The recirculating ball nut 4 is provided with a spherical curved surface 4-2, and a universal joint ring 3 is arranged on one side. The universal joint ring 3 has a curved surface structure 3-1 that is matched and connected to the recirculating ball nut 4. At the same time, on The inner ring 8 of the ball bearing 9 also has a universal joint spherical section that is matched and connected to the recirculating ball nut 4 . The above three parts constitute the basic structure that enables the recirculating ball nut to rotate in any direction with the center of the universal segment spherical surface as the center.

In order to transmit the torque from the pulley 7 to the recirculating ball nut 4, two cylindrical pins 6 are arranged symmetrically up and down on the curved surface structure 3-1 of the recirculating ball nut 4. The cylindrical pins 6 are installed to the recirculating ball nut 4 through an interference fit. In the circular hole slots 4-4 on both sides of the recirculating ball nut 4. Therefore, the recirculating ball nut 4 can Rotate about the axis passing through the two cylindrical pins 6.

On the inside of the pulley 7, there are two notches 7-1 arranged along the axial direction of the pulley 7. The notches 7-1 have two side surfaces formed by planes that are consistent with the generatrix of the outer cylindrical surface of the cylindrical pin 6. Therefore, the cylindrical pin 6 can slide in a direction parallel to the notch 7-1, thus forming a structure with the function that "the recirculating ball nut can rotate around an axis perpendicular to the axial direction of the screw screw".

Two rings 5 are arranged on the two cylindrical pins 6. The inner surface of the ring 5 and the outer surface of the cylindrical pin have a clearance fit, and the end surface of the cylindrical pin 6 is provided with a limiting flange structure 6-1. The ring 5 can be moved along the cylinder. The axis of the pin 6 rotates, and the outer surface of the ring 6 fits the notch 7-1 of the pulley. In practical applications, there is often a smaller gap on both sides of the ring 5 and the notch 7-1, so Only one side of the ring 5 fits with the notch 7-1. Therefore, this structure can change the relative sliding motion between the cylindrical pin 6 and the notch 7-1 into a relative rolling motion, thereby reducing the wear of parts.

A short cylindrical surface 4-3 is provided in the middle of the spherical curved surface 4-2 of the recirculating ball nut 4 to reduce the maximum radial size of the spherical surface. This structure allows the pulley 7 to have more radial arrangement space, reducing the size of the surface 7-3. diameter, use a smaller outer diameter of the pulley 7 to achieve a wider notch 7-1 arrangement, reduce the fitting pressure between the notch 7-1 and the cylindrical pin 6, thereby reducing friction.

In order to make the curved surface structure 3-1 of the universal joint ring 3 close to the recirculating ball nut 4 with the required axial pre-tightening force, a pre-tightening mechanism is provided on the other end surface of the universal joint ring 3. The pre-tightening mechanism consists of an annular The structure consists of a spring element 2 and a threaded locking ring 1. The spring element 2 is preferably a disc spring, but can also be designed as a wave spring. The threaded locking ring 1 is fixedly connected with the internal thread 7-2 on the inside of the end face of the pulley 7 in the form of an external thread, and is locked according to the set axial installation position so that the spring element 2 has a set axial pressure, thereby making the universal The curved surface structure 3-1 of the node ring 3 and the universal joint spherical section of the inner ring 8 of the ball bearing 9 are in contact with the spherical curved surface 4-2 of the recirculating ball nut from both sides.

In order to ensure that the pulley 7 can be rigidly connected to the inner ring 8 of the ball bearing 9, this solution can adopt the installation form of threaded connection, supplemented by commonly used thread glue or rivet points to prevent loosening. The structure is designed such that the internal thread 7-2 on the inner side of the end face of the pulley 7 is connected with the external thread of the inner ring 8 of the ball bearing 9, and the end face of the pulley 7 is close to the shoulder on the inner ring 8 of the ball bearing 9. same In order to compensate for the slight deviation between the axis of the pulley 7 and the inner ring 8 of the ball bearing 9 caused by the thread structure, which affects the fit of the universal joint structure, the outer cylindrical surface of the universal joint ring 3 corresponds to the pulley 7 The inner hole mating surface is installed with a clearance fit.

This device can prevent the radial load and bending moment of the screw from being directly transmitted to the inner ring 8 of the ball bearing 9, nor to the steel ball in the ball bearing 9 and the bearing outer ring; thereby reducing the ball For the external load on the bearing, a smaller bearing can be selected for the same external radial load design.

At the same time, the radial load of the screw will not be transmitted to the inner ring 8 of the ball bearing 9, which also means that the reverse force of the ball bearing 9 on the screw is reduced simultaneously. The diameter of the corresponding ball screw under radial load design can be reduced simultaneously.

The pulley 7 is driven by the external belt torque, and in order to avoid slippage or tooth skipping, the belt has internal belt tension. The pulley 7 is only connected to the inner ring 8 of the ball bearing 9, and due to the aforementioned The radial load will not be transmitted to the inner ring 8 of the ball bearing 9, and the relative position of the inner ring 8 of the ball bearing 9 will not be affected by the radial load from the outside, so that the relative position of the pulley 7 will not be affected. , which ensures that the tension of the belt remains constant, thereby preventing the belt from slipping or skipping teeth and improving the accuracy of the steering system.

The torque transmission structure of the device is mainly transmitted by two cylindrical pins 6 and annular rings 5. In principle, it achieves gap-free fit between parts. Therefore, in practical applications, a relatively tight fit of parts can be achieved and steering is avoided. The noise caused by the collision of parts in the system is eliminated, and the transmission efficiency is improved. At the same time, due to the larger diameter of the cylindrical pin 6, this solution can also transmit larger power assist torque, can be applied to higher power steering systems, and improves the life of parts.

The universal joint structure of the device is pre-tightened by the spring element 2. Since the arrangement space of the spring element, such as the butterfly spring, is larger, a more flexible pre-tightening force design range can be achieved, and a larger pre-tightening force can be achieved with a relatively simple structure. Tight force.

Example 2

A universal swing-type recirculating ball nut mechanism for an electronic power steering machine, including a recirculating ball nut, a ball Bearings and pulleys, a ball bearing 9 is set on one side of the outer edge of the recirculating ball nut 4, a pulley 7 is set on the other side of the outer edge of the recirculating ball nut 4, and the inner ring 8 of the recirculating ball bearing 9 is connected to the pulley 7 through threads Connection; a number of cylindrical pins 6 are embedded between the recirculating ball nut 4 and the pulley 7, and the outer surface of the cylindrical pins 6 fits the notches 7-1 of the pulley 7; the recirculating ball nut 4 is provided with a universal joint ring 3. The inner surface of the universal joint ring 3 is a curved surface structure 3-1, and the curved surface structure 3-1 matches the spherical curved surface 4-2 of the recirculating ball nut 4. In specific use, the screw transmits power to the recirculating ball nut 4. The recirculating ball nut 4 is driven by the screw to rotate and is subject to radial load and axial load. The cylindrical pin 6 can be in the two grooves on the inside of the pulley 7. Sliding in the mouth, the recirculating ball nut 4 simultaneously cooperates with the curved surface structure 3-1 of the universal joint ring 3, so that the recirculating ball nut 4 can rotate around an axis perpendicular to the screw axis.

Among them, as shown in Figure 3, the notch 7-1 has two side surfaces formed by planes that are tangent to the generatrix of the outer cylindrical surface of the cylindrical pin 6, and the cylindrical pin 6 can slide in a direction parallel to the notch 7-1. The notch 7-1 allows the cylindrical pin to slide in the notch 7-1 when the recirculating ball nut 4 receives uneven axial load from the screw or the screw fluctuates due to external fluctuations, and the curved surface structure 3-1 Cooperating with the notch 7-1, the recirculating ball nut 4 deflects at a small angle in the axial direction of the screw, preventing the inner ring of the spaced bearing from being subjected to the screw load when the axial load of the screw fluctuates. The influence of fluctuations; at the same time, as shown in Figures 6 and 8, the length of the curved structure notch 7-1 limits the range of the angle between the recirculating ball nut 4 and the screw axis. At the same time, the gap between the recirculating ball bearing 4 and the inner ring of the bearing ensures that even if the angle between the recirculating ball nut 4 and the screw axis reaches the maximum value, there will still be no gap between the recirculating ball nut 4 and the inner ring 8 of the recirculating ball bearing. Contact occurs, thereby ensuring that the radial load and bending moment of the screw will not directly act on the inner ring 8 of the ball bearing 9, nor will it be transmitted to the steel ball in the ball bearing 9 and the outer ring of the bearing.

As shown in Figure 4, the top of the cylindrical pin 6 is provided with a limiting flange structure 6-1, and a ring 5 is located on the outside of the cylindrical pin 6. The inner surface of the ring 5 and the outer surface of the cylindrical pin 6 have a clearance fit. The clearance fit makes the friction between the ring 5 and the cylindrical pin 6 smaller during the rotation of the recirculating ball nut 4, so that when the cylindrical pin 6 slides in the notch 7-1, the sliding of the ring 5 against the cylindrical pin 6 causes Buffer, flange knot The structure makes the friction between the recirculating ball nut 4 and the notch 7-1 smaller during the rotation process. At the same time, the top surface of the flange 6-1 is arc-shaped, which is convenient for the recirculating ball nut 4 to contact the notch 7-1. When the axis of the screw has an included angle, the rotating ball nut 4 rotates in the slot 7-1.

Among them, the ring 5 can rotate along the axis of the cylindrical pin 6. The upper end and the lower end of the inner side of the pulley 7 are respectively provided with notches 7-1. The notches 7-1 cooperate with the ring 5 so that the cylindrical pin 6 and the notch The sliding motion between 7-1 becomes the rolling motion of the ring 5, which reduces the wear of the cylindrical pin.

The cylindrical pin 6 can slide in the two notches 7-1 on the inside of the pulley 7, and the recirculating ball nut 4 can rotate along the axis of the cylindrical pin 6 when the cylindrical pin 6 slides to the set position, so that the recirculating ball nut 4 can Rotate around the axis perpendicular to the axis of the screw, so that when the cylindrical pin 6 slides in the notch 7-1, the ring 5 forms a buffer against the sliding of the cylindrical pin 6, which facilitates the recirculating ball nut 4 in the notch 7-1 When there is an included angle with the axis of the screw, the recirculating ball nut 4 can still rotate at a certain angle around the axis perpendicular to the axis of the screw.

Among them, there are at least two cylindrical pins 6 , and the two cylindrical pins 6 are respectively embedded in the upper end and lower end of the recirculating ball nut 4 . They are respectively arranged at the upper and lower ends of the recirculating ball nut 4, so that the two cylindrical pins can evenly bear the uneven load on the recirculating ball nut.

The two cylindrical pins 6 are symmetrical up and down about the recirculating ball nut 4 . This enables the recirculating ball nut 4 to withstand greater radial loads and bending moments under the support of the two cylindrical pins 6, thereby ensuring the stability and load capacity of the entire steering mechanism. Moreover, due to the reasonable distribution position of the cylindrical pins 6, the vibration and swing of the recirculating ball nut 4 can be effectively reduced, and the accuracy and stability of the system are improved. In addition, the arrangement of the two cylindrical pins 6 is also conducive to strengthening the fitting structure between the recirculating ball nut 4 and the pulley 7, thus improving the reliability and service life of the belt transmission. The entire structure is reasonably designed, practical and reliable.

In this embodiment, the outer surface of the recirculating ball nut 4 is connected by a long cylindrical surface 4-1 and a spherical curved surface 4-2. The short cylindrical surface 4 is located in the middle of the spherical curved surface 4-2 of the recirculating ball nut 4. -3. The upper and lower ends of the short cylindrical surface 4-3 are respectively provided with a circular hole slot 4-4, a long cylindrical surface 4-1 and a spherical curved surface 4-2, which can make the recirculating ball nut 4 swing and rotate under the action of torque. rotation, thereby reducing the impact of radial load and bending moment on the ball bearings and pulleys, and improving the stability and accuracy of the system. Due to the setting of the short cylindrical surface 4-3, the recirculating ball nut 4 can be further stabilized when bearing a load, preventing swinging and loss of control. The setting of the round hole groove 4-4 provides a way to adjust the assembly position and fitting clearance of the entire system. It is convenient to embed the ring 5, thereby effectively enhancing the performance and stability of the electronic power steering machine.

Among them, one end of the cylindrical pin 6 is located in the circular hole groove 4-4 of the recirculating ball nut 4, and the other end of the cylindrical pin 6 is located outside the recirculating ball nut 4, which can effectively prevent the recirculating ball nut 4 from colliding with other components during movement. interference and friction, thereby ensuring the smooth operation and accuracy of the entire mechanism

Specifically, one end of the cylindrical pin 6 close to the recirculating ball nut is connected with the circular hole groove 4-4 by an interference fit. It can make the contact area between the cylindrical pin 6 and the circular hole groove 4-4 larger, increase the contact tightness, thereby effectively improving the stability and load-bearing capacity of the cylindrical pin 6 in the recirculating ball nut 4, interference fit The connection method can also reduce the swing and looseness between the cylindrical pin 6 and the recirculating ball nut 4, further improving the accuracy and reliability of the entire system. At the same time, the interference fit connection method can also reduce interference and friction during rotation, reducing the friction resistance and energy loss of the system.

Specifically, the inner ring 8 of the ball bearing 9 also has a universal joint spherical section that is matched and connected to the recirculating ball nut 4 . Providing certain support for the rotation of the recirculating ball nut 4 can effectively improve the load-bearing capacity and stability of the recirculating ball nut 4. At the same time, it provides limits on the rotation range of the recirculating ball nut 4 to prevent contact between the recirculating ball nut 4 and the bearing inner ring 8. , the spherical section of the universal joint can effectively carry and distribute the load, reducing the pressure on the spherical surface structure 3-1, and improving its service life and reliability.

Among them, as shown in Figure 7, the inner surfaces of both ends of the pulley 7 are respectively provided with internal threads 7-2, one side inside the pulley 7 is provided with a reduction surface 7-3, and the other side inside the pulley 7 is provided with an inner hole for matching Face 7-4. The internal thread 7-2 can make the pulley 7 easy to connect and fix during use, and can support external loads and torques. At the same time, the arrangement of the reduced surface 7-3 inside the pulley 7 can effectively improve the internal structure of the pulley, reduce the mass, and reduce the resistance and inertia of movement. The design of the inner hole mating surface 7-4 can ensure the precise matching and connection between the inner hole of the pulley and other accessories, thereby ensuring the performance and transmission accuracy of the entire system.

Among them, the inner ring of the ball bearing 9 is provided with an inner ring 8, and one end of the inner ring 8 is located inside the ball bearing 9. The other end of the inner ring 8 is connected with the internal thread 7-2 on the inside of one end of the pulley 7 through a thread, which can effectively realize the connection between the ball bearing and the pulley, thereby improving the stability and load-bearing capacity of the entire mechanism. Since the inner ring 8 is located inside the ball bearing 9, it can effectively support radial and axial loads, thereby enhancing the load-bearing capacity and stability of the ball bearing 9 during rotation; and the threaded connection design can improve the firmness of the connection. , can effectively prevent the connection from loosening or breaking. In addition, the threaded connection can also greatly facilitate the installation, disassembly and maintenance of ball bearings, reduce its maintenance costs, and can effectively improve the accuracy, stability and reliability of the entire steering mechanism.

In this embodiment, a pre-tightening mechanism is provided on the end face of the universal joint ring 3 close to the pulley. The pre-tightening mechanism includes a spring element 2 and a threaded locking ring 1. There is a recirculating ball nut 4 between the recirculating ball nut 4 and the threaded locking ring 1. The spring element 2 and the universal joint ring 3 are arranged between the cylindrical pin 6 and the spring element 2 . A pre-tightening mechanism is provided on the end face of the universal joint ring 3 close to the pulley to generate additional pre-tightening force between the recirculating ball nut 4 and the threaded locking ring 1, thereby increasing the firmness and stability of the connection. At the same time, a spring element 2 is provided between the recirculating ball nut 4 and the threaded locking ring 1, which can reduce the impact of vibration and impact on the bearing and improve the durability and reliability of the entire system. The universal joint ring 3 is located between the cylindrical pin 6 and the spring element 2, which can prevent unnecessary friction and wear of the universal joint ring 3 during rotation, ensuring the normal operation of the entire mechanism, and has a compact structure and space saving. It can be used in situations where high-precision rotation and large torque transmission are required.

Wherein, the spring element is a disc spring or a wave spring. The spring element 2 has a set axial pressure, so that the curved surface structure 3-1 of the universal joint ring 3 and the universal joint spherical section of the inner ring 8 of the ball bearing 9 are pressed against the spherical shape of the recirculating ball nut from both sides. Surface 4-2. Examples of spring elements: butterfly springs have a larger layout space and can achieve a more flexible design range of preload force, and achieve a larger preload force with a relatively simple structure.

Although specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or changes can be made to these embodiments without departing from the principles and essence of the present invention. Revise. Accordingly, the scope of the present invention is defined by the appended claims.

Claims (16)

A universal swing-type recirculating ball nut mechanism for an electronic power steering machine, which includes a recirculating ball nut, a ball bearing, and a pulley. It is characterized in that: the ball bearing is set on one side of the outer edge of the recirculating ball nut (4). (9), a pulley (7) is set on the other side of the outer edge of the recirculating ball nut (4), and the inner ring (8) of the recirculating ball bearing (9) is connected to the pulley (7) through threads; A number of cylindrical pins (6) are embedded between the recirculating ball nut (4) and the pulley (7). The outer surface of the cylindrical pin (6) and the notch (7-1) of the pulley (7) ) fit together; the recirculating ball nut (4) is covered with a universal joint ring (3), the inner surface of the universal joint ring (3) is a curved surface structure (3-1), and the curved surface The structure (3-1) matches the spherical curved surface (4-2) of the recirculating ball nut (4). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to claim 1, characterized in that: the notch (7-1) has a generatrix that is consistent with the outer cylindrical surface of the cylindrical pin (6). The planes constitute two side surfaces, and the cylindrical pin (6) can slide in a direction parallel to the notch (7-1). A universal swing recirculating ball nut mechanism for electronic power steering gear according to any one of claims 1-2, characterized in that: the top of the cylindrical pin (6) is provided with a limiting flange structure (6- 1), a ring (5) is set on the outside of the cylindrical pin (6), and the inner surface of the ring (5) is in clearance fit with the outer surface of the cylindrical pin (6). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to claim 3, characterized in that the ring (5) can rotate along the axis of the cylindrical pin (6). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine as claimed in claim 4, characterized in that: the upper end and the lower end of the inner side of the pulley (7) are respectively provided with notches (7-1), The notch (7-1) matches the ring (5). A universal swing-type recirculating ball nut mechanism for an electronic power steering gear according to any one of claims 1 to 5, characterized in that: the cylindrical pin (6) can be mounted on both sides of the inner side of the pulley (7). It slides in each of the notches (7-1), and the recirculating ball nut 4 can rotate along the axis of the cylindrical pin (6) when the cylindrical pin (6) slides to a set position. A universal swing-type recirculating ball nut mechanism for an electronic power steering gear according to any one of claims 1 to 6, characterized in that: there are at least two cylindrical pins (6), two of which are Cylindrical pins (6) are respectively embedded in the upper and lower ends of the recirculating ball nut (4). A universal swing recirculating ball nut mechanism for an electronic power steering machine as claimed in claim 7, characterized in that: the two cylindrical pins (6) are symmetrical up and down with respect to the recirculating ball nut (4). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to any one of claims 1 to 8, characterized in that: the outer surface of the recirculating ball nut (4) is formed by a long cylindrical surface (4 -1) and a section of spherical curved surface (4-2). The middle part of the spherical curved surface (4-2) of the recirculating ball nut (4) is a short cylindrical surface (4-3). The upper end and lower end of the surface (4-3) are respectively provided with circular hole grooves (4-4). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to claim 9, characterized in that: one end of the cylindrical pin (6) is located in the circular hole groove of the recirculating ball nut (4). (4-4), the other end of the cylindrical pin (6) is located outside the recirculating ball nut (4). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to claim 10, characterized in that: one end of the cylindrical pin (6) close to the recirculating ball nut is connected with the circular hole groove (4- 4) For interference fit connection. A universal swing recirculating ball nut mechanism for an electronic power steering machine according to any one of claims 1 to 11, characterized in that: the inner ring (8) of the ball bearing (9) also has a The recirculating ball nut (4) matches the spherical section of the universal joint connected. A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to any one of claims 1 to 12, characterized in that: the inner surfaces of both ends of the pulley (7) are respectively provided with internal threads (7 -2), one side inside the pulley (7) is provided with a reduction surface (7-3), and the other side inside the pulley (7) is provided with an inner hole matching surface (7-4). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to claim 1, characterized in that: the inner ring of the ball bearing (9) is provided with an inner ring (8), and the inner ring (8) ) One end of the inner ring (8) is located inside the ball bearing (9), and the other end of the inner ring (8) is connected to the internal thread (7-2) on the inside of one end of the pulley (7) through threads. A universal swing-type recirculating ball nut mechanism for an electronic power steering gear according to any one of claims 1 to 14, characterized in that: the end face of the universal joint ring (3) close to the pulley is provided with a predetermined tight mechanism, The preloading mechanism includes a spring element (2) and a threaded locking ring (1). A spring element (2) is provided between the recirculating ball nut (4) and the threaded locking ring (1). The universal joint ring (3) is arranged between the cylindrical pin (6) and the spring element (2). A universal swing-type recirculating ball nut mechanism for an electronic power steering machine according to claim 15, characterized in that the spring element is a disc spring or a wave spring.