Windowless continuous raceway internal circulation screw

Abstract

The present application relates to a kind of windowless continuous raceway inner loop screw, belong to screw driving device technical field.It includes screw and the screw nut matched with it, steel ball is arranged between the two.The steel ball circulation structure includes the continuous internal thread raceway being set in the inner wall of screw nut and the inner concave reverse ball groove being integrally formed in the inner wall of screw nut, the start point and the end point of internal thread raceway are communicated by reverse ball groove, and constitute closed steel ball circulation loop.Screw nut inner wall is pre-set ball stopper seat, installs ball stopper for separating steel ball of different circulation period.Screw nut inner wall is provided with at least one steel ball circulation loop along the axial direction, and multiple steel ball circulation loops can be independently arranged.Reverse ball groove is directly formed in the inner wall of screw nut by cold forging process, and the outer diameter surface of screw nut is windowless closed structure.The present application has simple structure, low manufacturing cost, high reliability, low noise, and is suitable for precision transmission occasion.

Description

Technical Field

[0001] This invention belongs to the field of ball screw technology and relates to a windowless continuous raceway internal circulation ball screw. Background Technology

[0002] Ball screws are important actuators in the steering and braking systems of new energy vehicles, machine tools, and robots. The circulation methods of ball screws are divided into internal and external circulation. The steel balls, through a circulation device, return to the starting point after completing their helical forward motion, thus achieving a cyclical motion.

[0003] Traditional ball return mechanisms typically involve machining a window on the outer diameter surface of the nut, with the ball return mechanism installed within this window. The presence of this window significantly increases the machining cost of the nut, and the opening disrupts the nut's overall integrity, reducing its structural strength and load-bearing capacity. Another type of nut integrates the reverse channel directly onto the nut through extrusion molding. While this avoids the aforementioned drawbacks, the discontinuous thread raceway significantly impacts machining efficiency. Furthermore, the need for the cutting tool / grinding wheel to constantly move in and out of the raceway during machining makes it difficult to improve machining accuracy. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a windowless continuous raceway internal circulation lead screw, which can significantly reduce the machining difficulty of the nut.

[0005] According to the technical solution of the present invention: a windowless continuous raceway internal circulation lead screw includes a lead screw and a lead screw nut that cooperates with the lead screw. A steel ball is arranged between the lead screw and the lead screw nut. The steel ball circulates through a steel ball circulation structure. The steel ball circulation structure includes a continuous internal thread raceway provided on the inner wall of the lead screw nut and an inwardly recessed reverse ball groove integrally formed on the inner wall of the lead screw nut. At least one steel ball circulation loop is provided on the inner wall of the lead screw nut along the axial direction. The reverse ball groove connects the start and end points of the corresponding steel ball circulation loop. The steel balls are arranged in the steel ball circulation loop. Several ball stoppers are installed on the inner wall of the lead screw nut to separate the steel balls in different cycles; The ball stopper is installed on the ball stopper seat preset on the inner wall of the lead screw nut; The ball stopper has a protruding structure at its end and a corresponding recess in its seat. The ball stopper and the ball stopper seat are interference fit to achieve pre-assembly positioning. The ball stopper is embedded in the groove of the internal thread raceway to prevent the steel ball from falling out of the circulation track.

[0006] As a further improvement of the present invention, there are multiple steel ball circulation loops, and each steel ball circulation loop is independent of the others. Each steel ball circulation loop includes a set of corresponding reverse ball grooves and ball deflectors.

[0007] As a further improvement of the present invention, multiple steel ball circulation loops are arranged sequentially along the axial direction on the inner wall of the lead screw nut, and the reverse ball grooves of two adjacent steel ball circulation loops are staggered from each other in the circumferential direction.

[0008] As a further improvement of the present invention, the reverse ball groove is a recessed channel formed directly on the inner wall of the lead screw nut by cold forging process, and the outer diameter surface of the lead screw nut is a closed structure without windows.

[0009] As a further improvement of the present invention, the internal thread raceway is an uninterrupted continuous thread groove, which is suitable for one-time continuous tool pass forming in turning, milling or grinding processes.

[0010] As a further improvement of the present invention, the circulation curve of the reverse ball groove adopts a quintic curve to achieve a smooth transition of the steel ball.

[0011] As a further improvement of the present invention, the ball deflector is made of plastic material to reduce the vibration and noise generated by the impact of the steel ball.

[0012] The technical advantages of this invention are as follows: The invention employs an integrated cold-forged return ball raceway, which avoids slotting on the outer diameter surface of the nut, reducing processing difficulty, increasing the nut's strength, and reducing the possibility of grease leakage and foreign object intrusion; the use of continuously machined thread raceways allows for one-time machining regardless of whether the thread raceway is milled, turned, or ground; the use of plastic isolation blocks prevents interference between different circulating steel balls, reducing vibration during screw operation; the protruding structure at the end of the plastic isolation block allows it to be directly embedded in the nut during installation, improving assembly reliability; the cold-forged return ball raceway is entirely made of metal, resulting in high strength and improved durability of the reverse structure. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention.

[0014] Figure 2 This is a schematic diagram of the lead screw nut.

[0015] Figure 3 This is a schematic diagram of the ball deflector. Detailed Implementation

[0016] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0017] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0018] Figure 1-3 The components include a lead screw nut 1, an internal thread raceway 1.1, a reverse ball groove 1.2, a ball stopper seat 1.3, a lead screw 2, a steel ball 3, and a ball stopper 4.

[0019] like Figure 1-3 As shown, the present invention is a windowless continuous raceway internal circulation lead screw, including a lead screw 2 and a lead screw nut 1 that cooperates with the lead screw 2. A steel ball 3 is arranged between the lead screw 2 and the lead screw nut 1, and the steel ball 3 achieves circulation through a steel ball circulation structure.

[0020] The steel ball circulation structure includes a continuous internal thread raceway 1.1 provided on the inner wall of the lead screw nut 1 and an internally recessed reverse ball groove 1.2 integrally formed on the inner wall of the lead screw nut 1. The inner wall of the lead screw nut 1 is provided with at least one steel ball circulation loop along the axial direction. The reverse ball groove 1.2 connects the start and end points of the corresponding steel ball circulation loop. The steel balls 3 are arranged in the steel ball circulation loop.

[0021] A number of ball stoppers 4 are installed on the inner wall of the lead screw nut 1 to separate the steel balls 3 of different cycles. The ball stoppers 4 are installed on the ball stopper seat 1.3 preset on the inner wall of the lead screw nut 1.

[0022] There are multiple ball circulation loops, and each ball circulation loop is independent of the others. Each ball circulation loop includes a set of corresponding reverse ball grooves 1.2 and ball stoppers 4. This design allows each circulation loop to work independently, improving the load-bearing capacity and operational stability of the lead screw.

[0023] Multiple steel ball circulation loops are arranged sequentially along the axial direction on the inner wall of the lead screw nut 1, and the reverse ball grooves 1.2 of two adjacent steel ball circulation loops are staggered in the circumferential direction. This staggered arrangement design avoids excessive concentration of the reverse ball grooves 1.2 in the same axial position, ensuring the structural strength of the lead screw nut 1, while making the circulation of the steel balls 3 more uniform and smooth.

[0024] The reverse ball groove 1.2 is a recessed channel formed directly on the inner wall of the lead screw nut 1 through a cold forging process. The outer diameter surface of the lead screw nut 1 is a closed structure without windows. This one-piece molding design eliminates the disadvantage of traditional internal circulation lead screws requiring windows to be opened on the outer wall of the nut, improves the overall rigidity and sealing of the lead screw nut 1, and prevents external impurities from entering the circulation system.

[0025] The internal thread raceway 1.1 is a continuous thread groove without interruption, suitable for one-time continuous tool pass forming in turning, milling, or grinding processes. This design simplifies the machining process, improves machining efficiency and raceway machining accuracy, and ensures the smooth operation of the steel ball 3 in the raceway.

[0026] The circulation curve of the reverse ball groove 1.2 adopts a five-fold curve to achieve a smooth transition of the steel ball 3.

[0027] The quintic curve has good continuity and smoothness, which can reduce the impact and vibration of the steel ball during the circulation process, extend the service life of the lead screw, and reduce operating noise.

[0028] The ball stopper 4 is made of plastic to reduce the vibration and noise generated by the impact of the steel ball 3. The plastic material has good cushioning performance and wear resistance, which can effectively absorb the impact energy generated when the steel ball hits, reduce the noise generated by direct metal-to-metal collision, and improve the quietness of the lead screw operation.

[0029] The ball stopper 4 has a protruding structure at its end, and the ball stopper seat 1.3 has a corresponding recess. The ball stopper 4 and the ball stopper seat 1.3 are interference-fitted to achieve pre-assembly positioning; that is, the ball stopper 4 is installed on the ball stopper seat 1.3 pre-set on the inner wall of the lead screw nut 1. This snap-fit ​​design simplifies the installation process of the ball stopper, ensures that the ball stopper will not loosen or fall off during the operation of the lead screw, and improves assembly efficiency and operational reliability.

[0030] The ball stopper 4 is embedded in the groove of the internal thread raceway 1.1 to prevent the steel ball 3 from falling out of the circulation track. Through the combination of the above technical features, this windowless continuous raceway internal circulation screw achieves efficient circulation of the steel ball, improves the transmission efficiency and load-bearing capacity of the screw, and has the advantages of compact structure, good sealing, low noise, and long service life. It is suitable for various industrial applications such as precision transmission and high-speed motion.

[0031] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A windowless continuous raceway internal circulation lead screw, comprising a lead screw (2) and a lead screw nut (1) cooperating with the lead screw (2), wherein a steel ball (3) is disposed between the lead screw (2) and the lead screw nut (1), and the steel ball (3) circulates through a steel ball circulation structure, characterized in that: The steel ball circulation structure includes a continuous internal thread raceway (1.1) provided on the inner wall of the lead screw nut (1) and an internally recessed reverse ball groove (1.2) integrally formed on the inner wall of the lead screw nut (1). The inner wall of the lead screw nut (1) is provided with at least one steel ball circulation loop along the axial direction. The reverse ball groove (1.2) connects the start and end points of the corresponding steel ball circulation loop. The steel balls (3) are arranged in the steel ball circulation loop. Several ball stoppers (4) are installed on the inner wall of the lead screw nut (1) to separate the steel balls (3) of different cycles. The ball stopper (4) is installed on the ball stopper seat (1.3) pre-set on the inner wall of the lead screw nut (1). The ball stopper (4) has a protruding structure at its end and a corresponding recess in the ball stopper seat (1.3). The ball stopper (4) and the ball stopper seat (1.3) are interference fit to achieve pre-assembly positioning. The ball stopper (4) is embedded in the groove of the internal thread raceway (1.1) to prevent the steel ball (3) from falling out of the circulation track.

2. The windowless continuous raceway internal circulation screw as described in claim 1, characterized in that: The number of steel ball circulation loops is multiple, and each steel ball circulation loop is independent of the others. Each steel ball circulation loop includes a set of corresponding reverse ball grooves (1.2) and ball stoppers (4).

3. The windowless continuous raceway internal circulation screw as described in claim 2, characterized in that: Multiple steel ball circulation loops are arranged sequentially along the axial direction on the inner wall of the lead screw nut (1), and the reverse ball grooves (1.2) of two adjacent steel ball circulation loops are staggered in the circumferential direction.

4. The windowless continuous raceway internal circulation screw as described in claim 1, characterized in that: The reverse ball groove (1.2) is a recessed channel formed directly on the inner wall of the lead screw nut (1) by cold forging process, and the outer diameter surface of the lead screw nut (1) is a closed structure without windows.

5. The windowless continuous raceway internal circulation screw as described in claim 1, characterized in that: The internal thread raceway (1.1) is a continuous thread groove without interruption, suitable for one-time continuous tool pass forming in turning, milling or grinding processes.

6. The windowless continuous raceway internal circulation screw as described in claim 1, characterized in that: The circulation curve of the reverse ball groove (1.2) adopts a five-fold curve to achieve a smooth transition of the steel ball (3).

7. The windowless continuous raceway internal circulation screw as described in claim 1, characterized in that: The ball deflector (4) is made of plastic material to reduce the vibration and noise generated by the impact of the steel ball (3).

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