Sliding sleeve type ball reciprocating screw rod

Abstract

The invention belongs to the technical field of reciprocating lead screws, and particularly relates to a sliding sleeve type ball reciprocating lead screw which comprises a lead screw body, a sliding sleeve, a sliding sleeve and a sliding sleeve, and the surface of the lead screw body is provided with two thread grooves with the same thread pitch and opposite rotation directions; the sliding sleeve assembly is arranged on the surface of the lead screw in a sliding and sleeving mode; the ball is movably arranged between the threaded groove and the sliding sleeve assembly; the sliding sleeve is simple in structure and easy and convenient to assemble, the friction coefficient in the sliding sleeve is effectively reduced by reducing the number of the used balls, the impact resistance can be improved, and the service life of the whole structure is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of reciprocating screw technology, and particularly relates to a sliding sleeve type ball reciprocating screw. Background Technology

[0002] A reciprocating lead screw is a precision mechanical component that can convert rotary motion into linear reciprocating motion. It is commonly used in CNC machine tools for workpiece movement, robot joint transmission, medical device equipment for movement and positioning, oilfield equipment for reciprocating motion, printing plate for precise movement in printing machinery, and automatic handling and positioning of workpieces in automated equipment.

[0003] Existing internal circulation reciprocating screws have a ball circulation channel inside the slider, which needs to fill the inside of the nut with balls. Conventional ball screws usually have more than 10 balls, and an S-shaped reverse ball return device is set in the ball circulation channel to achieve internal circulation of the balls. Its structure is relatively complex, difficult to manufacture, and the large number of balls results in a high coefficient of friction, which can easily generate large friction during use, causing local overheating and accuracy decay, and reducing its service life. Summary of the Invention

[0004] The purpose of this invention is to provide a sliding sleeve type ball reciprocating screw, comprising: The lead screw has two threaded grooves with the same pitch and opposite directions on its surface. A sliding sleeve assembly is slidably sleeved on the surface of the lead screw; The ball bearing is movably disposed between the threaded groove and the sliding sleeve assembly.

[0005] Preferably, the sliding sleeve assembly is composed of three arc-shaped sliders spliced ​​together, including a first slider and two second sliders, and the arc-shaped sliders are fixed together by bolts.

[0006] Preferably, a positioning groove is provided at the center of the concave surface of the first slider, and a through hole is provided at the bottom of the positioning groove, the diameter of the positioning groove being larger than the diameter of the through hole.

[0007] Preferably, the concave surface of the second slider is provided with an annular reversing groove, and the bottom of the annular reversing groove is provided with a plurality of through holes.

[0008] Preferably, the two ends of the two threaded grooves are connected by a transition curve.

[0009] The beneficial effects of this invention are: By creating a positioning groove at the center of the concave surface of the first slider in the sliding sleeve assembly and an annular reversing groove at the concave surfaces of the two second sliders, combined with the special thread groove shape on the surface of the lead screw, the number of balls required for the linear reciprocating motion of the sliding sleeve assembly can be reduced to 3. This directly reduces the contact points between the balls and the lead screw and the sliding sleeve assembly, thereby significantly reducing the coefficient of friction between the sliding sleeve assembly, the balls and the lead screw, and extending the service life of the structure.

[0010] By using a segmented sliding sleeve assembly, each part can be processed independently, reducing the complexity and difficulty of the overall processing, which helps to improve production efficiency and reduce manufacturing costs. Furthermore, due to the reduction in the number of balls, the distribution of balls during transmission is more uniform, further improving transmission accuracy.

[0011] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0012] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the sliding sleeve assembly structure according to an embodiment of the present invention; Figure 3 This is a first slider structure diagram according to an embodiment of the present invention; Figure 4 This is a second slider structure diagram according to an embodiment of the present invention.

[0014] In the picture: 1. Lead screw; 2. Threaded groove; 3. Sliding sleeve assembly; 4. First slider; 5. Second slider; 6. Positioning groove; 7. Through hole; 8. Annular reversing groove; 9. Boss surface; 10. Groove surface. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] like Figures 1 to 4 As shown, this embodiment provides a sliding sleeve type ball reciprocating screw, including: The lead screw 1 is made of 40Cr high-strength alloy steel, and its surface has two threaded grooves 2 with the same pitch and opposite directions. A sliding sleeve assembly 3 is slidably fitted onto the surface of the lead screw 1. Three balls are movably disposed between the threaded grooves 2 and the sliding sleeve assembly 3. The lead screw 1 undergoes quenching and tempering treatment to improve wear resistance, and its surface can be further hardened with high-frequency quenching to form a 0.2mm hardened layer, reducing wear during ball bearing transmission. The threaded grooves 2 are precision ground to a surface roughness of Ra 0.7μm, ensuring transmission accuracy.

[0017] The sliding sleeve assembly 3 is composed of three arc-shaped sliders, including a first slider 4 and two second sliders 5. Each arc-shaped slider has bolt holes at its four corners, one side is machined into a boss surface 9, and the other side into a groove surface 10. The boss surface 9 and the groove surface 10 can fit together perfectly to prevent axial sliding between the arc-shaped sliders. Each arc-shaped slider is then fixed together with bolts to further increase its stability. This segmented design allows each slider to be machined independently, greatly reducing the complexity and difficulty of the overall machining. A positioning groove 6 is provided at the center of the concave surface of the first slider 4. A through hole 7 is provided at the bottom of the positioning groove 6, penetrating the first slider 4. The diameter of the positioning groove 6 is larger than the diameter of the through hole 7. The function of the positioning groove 6 is to provide accurate positioning for the ball bearing, ensuring that the ball bearing can stably remain in a specific position during movement, reducing deviations during rolling. The ball bearing located in the positioning groove 6 has a certain amount of room to move within the positioning groove 6, while also being able to contact the threaded groove 2 on the surface of the lead screw 1. The second slider 5 has an annular reversing groove 8 on its concave surface, and several through holes 7 are formed at the bottom of the annular reversing groove 8. Each of the two second sliders 5 is equipped with a ball bearing. The function of the annular reversing groove 8 is to cooperate with two intersecting threaded grooves 2, so that the ball bearing can move in an elliptical motion within the annular reversing groove 8 and smoothly switch from one threaded groove 2 to another. The two through holes 7 are used to facilitate the injection of oil into the sliding sleeve assembly 3 from the outside, thus achieving a lubrication effect.

[0018] When the lead screw 1 rotates under the drive of the motor, the three balls simultaneously contact the threaded grooves 2 and the sliding sleeve assembly 3 on the surface of the lead screw 1. The helix angle of the two threaded grooves 2 generates an axial component force, which pushes the sliding sleeve assembly 3 to move axially. Among them, the positioning groove 6 is used to limit the position of one ball, ensuring that the ball is always on the center line of the threaded groove 2, serving as the main transmission point. The two annular reversing grooves 8 are used to accommodate the other two balls respectively. When the sliding sleeve assembly 3 moves to the end of the threaded groove 2, the annular reversing groove 8 guides the ball to switch from one threaded groove 2 to another, realizing the reversal.

[0019] The two ends of the two threaded grooves 2 are connected by a transition curve. The design of the transition curve allows the ball to smoothly transition at the end of the threaded groove 2, guiding the sliding sleeve assembly 3 to naturally change direction at the end of the threaded groove 2, avoiding impact and wear caused by sudden turning, and ensuring the smoothness and continuity of the reciprocating motion of the sliding sleeve assembly 3.

[0020] In summary, this embodiment requires only three balls to achieve transmission, reducing the number of contact points, lowering friction and wear, and forming a stable triangular support structure. This ensures that the sliding sleeve assembly is subjected to uniform force during movement, avoiding uneven loading and vibration. When the balls roll in the threaded groove 2, they are constrained by the axial component of the helical groove 2 and the sliding sleeve assembly 3, moving linearly along the axis of the lead screw 1. The design of the positioning groove 6 and the annular reversing groove 8 ensures that the balls are always in the correct position, preventing deviation or derailment. At the same time, reducing the number of balls to three directly reduces the contact points between the balls and the lead screw 1 and the sliding sleeve assembly 3. Combined with the segmented design of the sliding sleeve assembly 3, the ball distribution is more uniform, the coefficient of friction is reduced by about 40%, and the service life is effectively extended.

[0021] All the devices selected in this application (parts whose specific structures are not specified) are general standard parts or parts known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0022] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A sliding sleeve type ball reciprocating screw, characterized in that, include: The lead screw (1) has two threaded grooves (2) with the same pitch and opposite direction on its surface. The sliding sleeve assembly (3) is slidably sleeved on the surface of the lead screw (1); The ball bearing is movably disposed between the threaded groove (2) and the sliding sleeve assembly (3).

2. The sliding sleeve type ball reciprocating screw according to claim 1, characterized in that: The sliding sleeve assembly (3) is composed of three arc-shaped sliders spliced ​​together, including a first slider (4) and two second sliders (5), and the arc-shaped sliders are fixed together by bolts.

3. The sliding sleeve type ball reciprocating screw according to claim 2, characterized in that: A positioning groove (6) is provided at the center of the concave surface of the first slider (4), and a through hole (7) is provided at the bottom of the positioning groove (6) through the first slider (4). The diameter of the positioning groove (6) is larger than the diameter of the through hole (7).

4. The sliding sleeve type ball reciprocating screw according to claim 3, characterized in that: The second slider (5) has an annular reversing groove (8) on its concave surface, and the bottom of the annular reversing groove (8) has several through holes (7).

5. The sliding sleeve type ball reciprocating screw according to claim 4, characterized in that: The two ends of the two threaded grooves (2) are connected by a transition curve.

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