Ball assembly device for ball screw

Abstract

The application discloses a ball assembling equipment of a ball screw, which is applied to a continuous ball assembling production line and is provided with a rotary driving mechanism, a flow channel rod, a push rod assembly and a control unit. The flow channel rod is arranged at the center of a nut part, an internal inclined flow channel is arranged in the flow channel rod, and a circulation channel inlet of the nut is communicated with the end of the flow channel. Then the push rod assembly is used for adsorbing balls and controlling the movement of the balls along the flow channel. The control unit is electrically connected to the push rod assembly and the rotary driving mechanism, the push rod assembly is controlled to push the balls into the circulation channel, the nut part is controlled to rotate to make the circulation channel inlet and the flow channel outlet communicated, and the circulation channel inlet and the flow channel outlet are staggered after the balls enter, and the push rod assembly keeps sealing the flow channel outlet when the circulation channel inlet and the flow channel outlet are staggered. The application realizes the continuous assembling and backflow prevention of the balls in the reverser, has high assembling success rate, good consistency, high automation degree, good production line compatibility and flexible level.

Description

Technical Field

[0001] This invention relates to a ball screw assembly device, specifically a ball screw assembly device. Background Technology

[0002] Ball screws are important transmission components, and their assembly quality directly affects the transmission accuracy, smoothness, and service life of equipment. During the assembly process, the balls must be installed one by one into the nut.

[0003] In existing technologies, ball screw assembly is mostly done manually or semi-automatically, which suffers from low assembly efficiency, poor consistency, and high skill requirements for operators. With the development of automated production lines, although some automated assembly equipment has emerged, existing technologies mainly address filling the gap between the nut and the tool with balls, such as by forcibly pressing them one by one into the helical channel of the nut with a pressure rod. This can easily cause the balls to fall out and makes it difficult to ensure assembly consistency and cycle rate.

[0004] Furthermore, with the expansion of ball screws into advanced fields such as robotics, the application of lightweight ball screws has begun. These screws are very small in weight and size, and the installation positions of the balls and the screw are difficult to match, which further increases the difficulty of installing the balls.

[0005] Therefore, a ball screw assembly device is needed to complete the fully automated assembly of the balls and maintain the consistency and cycle capability of the assembly process. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention provides a ball assembly device for a ball screw, including a rotary drive mechanism, a flow channel rod, a push rod assembly, and a control unit. The flow channel rod is located at the center of the nut portion and has a flow channel for conveying the balls inside. The flow channel is inclined, and the end of the flow channel forms a flow channel outlet facing the circulation channel inlet of the ball screw. The push rod assembly is used to attract the balls and control the balls to move along the flow channel. The control unit is electrically connected to the push rod assembly and the rotary drive mechanism, controlling the push rod assembly to push the balls into the flow channel and push the balls from the flow channel outlet into the circulation channel. At the same time, the control unit controls the nut portion of the ball screw to rotate, so that the circulation channel inlet of the ball screw is connected to the flow channel outlet, and after the balls enter the circulation channel, the circulation channel inlet and the flow channel outlet are misaligned. The push rod assembly maintains the blockage of the flow channel outlet when the circulation channel inlet and the flow channel outlet are misaligned.

[0007] Furthermore, the push rod assembly includes a housing, and an inner rod and an outer rod coaxially disposed within the housing, wherein the inner rod is driven to move axially by a vertical drive member.

[0008] Furthermore, a compression spring is connected between the inner rod and the outer rod.

[0009] Furthermore, air holes are provided at the center of both the inner rod and the outer rod, and the side of the casing is connected to an external air source through an air pipe connector.

[0010] Furthermore, the vertical drive component is a cylinder, the cylinder body of which is connected to the top of the housing via a connecting block, and the inner rod is connected to the output end of the cylinder.

[0011] Furthermore, the inclination angle of the flow channel is 40-70°.

[0012] Furthermore, the rotary drive mechanism includes a hollow rotary platform and a servo motor that drives the hollow rotary platform, with the nut portion connected to the hollow rotary platform via a fixing clamp.

[0013] Furthermore, the fixing fixture includes a fixing sleeve connected to the hollow rotating platform. The fixing sleeve has a rod portion below its head and a linear bearing at the bottom of the rod portion. The flow channel rod is connected to the fixing sleeve through the linear bearing.

[0014] Furthermore, it also includes a lifting mechanism, the bottom of which is connected to the lifting mechanism via a lifting plate.

[0015] This invention discloses a ball assembly device for ball screws, applicable to continuous ball assembly production lines. It includes a rotary drive mechanism, a flow channel rod, a pusher assembly, and a control unit. The flow channel rod is positioned at the center of the nut section, with an inclined flow channel inside. The end of the flow channel connects to the inlet of the nut's circulation channel. The pusher assembly then attracts the balls and controls their movement along the flow channel. The control unit is electrically connected to the pusher assembly and the rotary drive mechanism, controlling the pusher assembly to push the balls into the circulation channel. Simultaneously, it controls the rotation of the nut section to connect the circulation channel inlet with the flow channel outlet, and after the balls enter, the two are separated. The pusher assembly maintains a seal on the flow channel outlet during this separation. This invention achieves precise assembly and anti-backflow of the balls inside the reverser, with a high assembly success rate, good consistency, high automation, and good production line compatibility and flexibility.

[0016] The control unit can coordinate and control the rotary drive mechanism, push rod assembly, lifting mechanism, and pneumatic system, achieving fully automated operation of actions such as rotary positioning, flexible pushing, backflow prevention and sealing, and reset cycle. This not only improves the assembly cycle time but also ensures the accuracy of each step, guaranteeing the reliability of the assembly process. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the ball bearing assembly equipment of the present invention; Figure 2 This is a schematic diagram of the nut section; Figure 3This is a structural schematic diagram of the push rod assembly; Figure 4 This is a schematic diagram showing the connection between the rotary drive mechanism and the lifting mechanism; Figure 5 This is a schematic diagram showing the connection between the lifting mechanism and the fixed sleeve; Figure 6 This is an exploded view of the flow channel rod and the fixed sleeve; Figure 7 This is a schematic diagram of the flow channel rod head; Figure 8 This is a cross-sectional view of the flow channel rod; Figure 9 This is a schematic diagram of the flow channel rod inside the nut section.

[0018] Reference numerals: nut 1, circulation channel 11, ball bearing 12; Integrated bracket 2; Push rod assembly 3, fixing plate 31, elongated hole 32, sleeve 33, air pipe connector 34, inner rod 35, outer rod 36, cylinder 37, connecting block 38, compression spring 39; Flow channel rod 4, oil-proof bushing 41, flow channel 42, flow channel inlet 43, flow channel outlet 44; Lifting mechanism 5, lifting plate 51; Rotary drive mechanism 6, hollow rotary platform 61, servo motor 62, fixed sleeve 63, head 631, rod 632, linear bearing 64, pressure block 65, lateral screw 66; Detailed Implementation

[0019] like Figure 1 The ball screw assembly equipment shown is used in a continuous ball screw assembly production line. The assembly line is equipped with a matching ball feeding system, such as a vibratory feeder and a feeder. The ball screw includes components such as... Figure 2 The nut part 1 shown has a reversing device on its peripheral wall to provide a circulation channel 11 for the internal balls 12. The assembly equipment includes a push rod assembly 3 and a rotary drive mechanism 6. The rotary drive mechanism 6 is used to fix the position of the lead screw and drive it to rotate around its own center. The push rod assembly 3 is connected to an external air passage to realize the transfer and assembly of the balls 12 through gas.

[0020] The rotary drive mechanism 6 employs a hollow rotary platform 61 driven by a servo motor 62. The hollow rotary platform 61 incorporates a high-precision harmonic reducer or planetary reducer, which, in conjunction with the servo motor 62, ensures repeatable positioning accuracy. A fixing fixture is provided on the hollow rotary platform 61, through which the nut portion 1 of the ball screw is connected to the upper part of the hollow rotary platform 61 and can be driven to rotate by the servo motor 62. A flow channel rod 4 is located at the center of the nut portion 1, extending from below the nut portion 1. The hollow hole of the hollow rotary platform 61 allows the flow channel rod 4 to pass through without interference.

[0021] Specifically, such as Figures 4 to 6 The fixing fixture shown includes a fixing sleeve 63 with a T-shaped cross-section. The head 631 of the fixing sleeve 63 is fixedly connected to the output flange of the hollow rotary platform 61. The center of the fixing sleeve 63 has a central hole for inserting the flow channel rod 4 and the nut part 1. A pressure block 65 is fixedly installed on the top of the fixing sleeve 63. A lateral screw 66 is provided on the pressure block 65 corresponding to the position of the reverser. The inner side of the lateral screw 66 can abut against the outer surface of the reverser, applying radial clamping force to the reverser and the nut part 1. While fixing the nut part 1, it restricts the position of the reverser to prevent it from changing position during assembly. Through this fixing fixture, the nut part 1 and the hollow rotary platform 61 are connected as a whole, rotating synchronously with the hollow rotary platform 61.

[0022] Below the head 631 of the fixed sleeve 63 is a rod 632, which extends vertically. A linear bearing 64 is provided at the bottom of the rod 632. The flow channel rod 4 is connected to the fixed sleeve 63 through the linear bearing 64. The linear bearing 64 can provide radial support and guidance for the flow channel rod 4, keeping its central position stable.

[0023] Furthermore, an oil-proof bushing 41 is provided between the flow channel rod 4 and the linear bearing 64 to absorb minor vibrations while preventing lubricating grease from splashing.

[0024] It also has Figure 4 The lifting mechanism 5 shown has the bottom of the flow channel rod 4 connected to the slider of the lifting mechanism 5 via a lifting plate 51. The lifting mechanism 5 controls the vertical movement of the flow channel rod 4, so that the flow channel rod 4 moves to the target assembly position.

[0025] In this embodiment, the lifting mechanism 5 is a lifting slide module. The lifting slide module and the hollow rotating platform 61 are fixedly connected to an integrated bracket 2, providing an installation reference for the hollow rotating platform 61 and the lifting slide module, ensuring their coaxial installation, and thus ensuring the operational stability of the entire system. The integrated bracket 2 can be installed on an external three-dimensional moving module to control its spatial movement, facilitating connection with upstream and downstream processes.

[0026] like Figure 7 , Figure 8 The flow channel rod 4 shown is a conveying and guiding component for the ball 12. Its main body is a solid rod with a flow channel 42 machined inside for the ball 12 to pass through. The cross-sectional width of the flow channel 42 is slightly larger than the diameter of the ball 12. This not only restrains the ball 12 and prevents it from rolling inside the flow channel 42, but also prevents the ball 12 from getting stuck inside the flow channel 42.

[0027] The inlet of the flow channel 42 is located at the top of the flow channel rod 4, and the outlet is located on the side of the flow channel rod 4, directly opposite the inlet of the circulation channel 11, forming an inclined channel connecting the ball feeding mechanism and the reverser. The inlet cross-section of the flow channel 42 is an outwardly flared curved surface, which facilitates the insertion of the balls 12 and reduces the alignment deviation of the installed balls 12. The radial angle between the central axis of the flow channel 42 and the radial direction of the flow channel rod 4 is preferably between 40 degrees and 70 degrees, so as to match the spatial orientation of the inlet of the reverser circulation channel 11 on the radial cross-section of the nut.

[0028] like Figure 3 The push rod assembly 3 shown is the movement control component for the ball bearing 12 in this embodiment. It is connected to an external air circuit and controls the feeding and movement of the ball bearing 12 through adsorption. The push rod assembly 3 is detachably mounted on a fixed plate 31. The surface of the fixed plate 31 has elongated holes 32 to accommodate different sizes of nut parts 1 and reversing devices. The fixed plate 31 can be mounted on an external robot or moving module to realize the movement and direction adjustment of the push rod assembly 3.

[0029] The main body of the push rod assembly 3 is a pen-shaped housing 33, the top of which is firmly connected to the fixing plate 31 via a flange. The push rod is coaxially mounted inside the housing 33, and an air pipe connector 34 is machined on the side of the housing 33 for connecting to an external air passage to provide adsorption negative pressure for the push rod.

[0030] In this embodiment, the push rod includes an inner rod 35 and an outer rod 36 coaxially mounted. The outer rod 36 is smaller than the cross-sectional dimension of the flow channel 42, allowing the outer rod 36 to carry the ball bearings 12 into the flow channel 42. Both the outer rod 36 and the inner rod 35 have air holes at their centers, which communicate with the air pipe connector 34. When the external adsorption device is activated, a negative pressure is generated between the center of the inner rod 35 and the outer rod 36, thereby increasing the adsorption effect on the ball bearings 12.

[0031] The inner rod 35 can be driven axially by a vertical drive component, which in this embodiment is a cylinder 37. The cylinder body of the cylinder 37 is fixed to the top of the housing 33 by a connecting block 38, and its piston rod extends downward and is connected to the upper end of the inner rod 35 through a threaded joint, converting the reciprocating motion of the cylinder 37 into the axial motion of the inner rod 35. The intake and exhaust of the cylinder 37 can be precisely controlled by a solenoid valve, which can realize the extension, retraction, and stopping of the inner rod 35.

[0032] The inclination direction of the push rod is basically consistent with the inclination direction of the flow channel 42. Each of the inner rod 35 and outer rod 36 has a connector installed at its head. The connector of the inner rod 35 is located above the outer rod 36, and a compression spring 39 connects the two connectors, providing a certain degree of elastic connection between the inner rod 35 and the outer rod 36. When the cylinder 37 drives the inner rod 35 downwards, the inner rod 35 first overcomes the spring force and transmits the force to the outer rod 36 through the compression spring 39, providing a buffer for the force transmission. Meanwhile, the end of the outer rod 36 contacts the ball 12, compressing the compression spring 39, making the thrust flexible and avoiding rigid impact. This thrust allows the ball 12 to overcome the resistance exerted by the flow channel 42 as it moves inclined along the flow channel 42, enabling the ball 12 to pass smoothly and unimpeded through the flow channel 42.

[0033] The difference in inner diameter between the inner rod 35 and the outer rod 36 is controlled to be no more than 0.5 mm to ensure that the inner rod 35 does not wobble excessively when moving within the outer rod 36. When the inner rod 35 moves to its limit relative to the outer rod 36, its end face can be flush with or protrude from the end face of the outer rod 36, providing an outward thrust to the ball 12. At this time, the end face of the outer rod 36 is exactly located at the flow channel outlet 44. Since the inlet size of the circulation channel 11 is slightly larger than the size of the ball 12, and there is no hard limit on the ball 12 by the spiral channel in conventional technology, the ball 12 may flow back to the flow channel outlet 44 after the thrust is removed. By controlling the extension position of the push rod assembly 3 to keep it at the position of the flow channel outlet 44, the retraction of the ball 12 is blocked; at this time, controlling the rotation of the nut part 1 can restrict the ball 12 within the circulation channel 11.

[0034] The assembly equipment also includes a control unit. The rotary drive mechanism 6, the vertical drive component and pneumatic system of the push rod assembly 3, the lifting mechanism 5, and the external moving module can all be connected to the control unit and controlled according to a pre-set program. Figure 1 and Figure 9 The control process for each component is as follows: Preparation before assembly: Place the nut part 1 into the clamping position of the hollow rotating platform 61, tighten the lateral screw 66, the nut part 1 is connected to the top of the hollow rotating platform 61 through the fixing sleeve 63, and can rotate with the hollow rotating platform 61; control the flow channel rod 4 to extend from the bottom of the nut part 1 through the lifting mechanism 5 until the flow channel outlet 44 of the flow channel rod 4 and the inlet of the circulation channel 11 of the reverser of the nut part 1 are approximately on the same plane; the outer rod 36 picks up the ball 12 from the feeding mechanism and moves it to the top of the flow channel rod 4.

[0035] Ball delivery: Ball 12 is inserted through the flow channel inlet 43. The cylinder 37 of the push rod assembly 3 is activated, controlling the inner rod 35 to continuously move downward. Pressure is transmitted to the outer rod 36 through the compression spring 39, pushing the ball 12 forward along the flow channel 42 to the flow channel outlet 44. The rotary drive mechanism 6 is activated, controlling the nut part 1 to rotate until the inlet of the circulation channel 11 is aligned with the flow channel outlet 44.

[0036] Anti-reverse rotation: Continue to control cylinder 37 of push rod assembly 3, press down inner rod 35, and push ball 12 into circulation channel 11. Close the adsorption air path control of push rod assembly 3, and control outer rod 36 and inner rod 35 to stop at flow channel outlet 44. At this time, the ends of inner rod 35 and outer rod 36 just block flow channel outlet 44, forming an obstruction. This can prevent ball 12 in circulation channel 11 from flowing back into flow channel rod 4 due to gravity or vibration. Rotation drive mechanism 6 resets, so that the inlet of circulation channel 11 and flow channel outlet 44 are misaligned. At this time, ball 12 can stay in circulation channel 11.

[0037] Reset Cycle: After ball bearing 12 is assembled, the control unit controls the cylinder 37 of the push rod assembly 3 to retract. The inner rod 35 and outer rod 36 reset under the action of the compression spring 39, releasing the blockage on the flow channel outlet 44. The next ball bearing 12 is picked up, and the rotary drive mechanism 6 starts when the ball bearing 12 reaches the flow channel outlet 44, aligning the inlet of the circulation channel 11 with the flow channel outlet 44. The push rod assembly 3 then presses the current ball bearing 12 and the previously filled ball bearing 12 into the circulation channel 11. This cycle continues until all ball bearing 12 are assembled.

[0038] This embodiment constructs a ball screw ball assembly device with high circulation degree and high flexibility, realizing the assembly and anti-backflow of the internal balls 12 of the reverser, with a high circulation degree and consistency, and a high degree of automation.

Claims

1. A ball assembly device for a ball screw, characterized in that: Includes a rotary drive mechanism (6) for driving the nut part (1) of the ball screw to rotate along its central axis; The flow channel rod (4) is located at the center of the nut part (1), and a flow channel (42) for conveying the ball (12) is provided inside. The flow channel (42) is inclined, and the end of the flow channel (42) forms a flow channel outlet (44) facing the inlet of the circulation channel (11) of the ball screw. A push rod assembly (3) is used to attract the ball (12) and control the ball (12) to move along the flow channel (42); The control unit is electrically connected to the push rod assembly (3) and the rotary drive mechanism (6), controlling the push rod assembly (3) to push the ball (12) into the flow channel (42) and push the ball (12) from the flow channel outlet (44) into the circulation channel (11); at the same time, controlling the nut part (1) of the ball screw to rotate, so that the inlet of the circulation channel (11) of the ball screw is connected to the flow channel outlet (44), and after the ball (12) enters the circulation channel (11), the inlet of the circulation channel (11) is separated from the flow channel outlet (44); the push rod assembly (3) maintains the blockage of the flow channel outlet (44) when the inlet of the circulation channel (11) is separated from the flow channel outlet (44); The push rod assembly (3) includes a housing (33), and an inner rod (35) and an outer rod (36) coaxially disposed within the housing (33). The inner rod (35) is driven to move axially by a vertical drive member. A compression spring (39) is connected between the inner rod (35) and the outer rod (36). The inner rod (35) and the outer rod (36) are both provided with air holes at their centers, and the side of the casing (33) is connected to an external air source through an air pipe connector (34).

2. The ball assembly equipment for a ball screw as described in claim 1, characterized in that: The vertical drive component is a cylinder (37). The cylinder body of the cylinder (37) is connected to the top of the casing (33) via a connecting block (38), and the inner rod (35) is connected to the output end of the cylinder (37).

3. The ball assembly equipment for a ball screw as described in claim 1, characterized in that: The inclination angle of the flow channel (42) is 40-70°.

4. The ball assembly equipment for a ball screw as described in claim 1, characterized in that: The rotary drive mechanism (6) includes a hollow rotary platform (61) and a servo motor (62) that drives the hollow rotary platform (61). The nut part (1) is connected to the hollow rotary platform (61) by a fixing clamp.

5. The ball assembly equipment for a ball screw as described in claim 4, characterized in that: The fixing fixture includes a fixing sleeve (63) connected to the hollow rotating platform (61). A rod (632) is provided below the head (631) of the fixing sleeve (63), and a linear bearing (64) is provided at the bottom of the rod (632). The flow channel rod (4) is connected to the fixing sleeve (63) through the linear bearing (64).

6. The ball assembly equipment for a ball screw as described in claim 1, characterized in that: It also includes a lifting mechanism (5), the bottom of which is connected to the lifting mechanism (5) via a lifting plate (51).

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