Ball screw assembly device and method

Abstract

The invention discloses a ball screw pair assembling device and method. The ball screw pair assembling device comprises a screw rotating table, a nut fixing rack and a screw pair assembling tool. The lead screw rotating table is used for fixing the ball screw in the vertical direction and driving the ball screw to rotate. The nut fixing rack is used for fixing the ball nut and adjusting the position of the ball nut. The lead screw pair assembly tool comprises a sleeve, a sleeve cover and an anti-rotation strip. When the lead screw rotating table drives the ball lead screw to rotate in the forward direction, the steel balls can flow out of the steel ball outlet under the action of gravity, enter the reverser through the notch and enter a screw channel of the ball nut along with rotation of the ball lead screw. According to the invention, a complex manual assembly process is simplified into simple clamping and starting actions, so that the assembly time of ball screw byproducts is greatly shortened, and the assembly efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of precision transmission technology, and particularly relates to a ball screw assembly device and method. Background Technology

[0002] A ball screw assembly consists of a ball screw, ball nut, return mechanism, and multiple steel balls.

[0003] In the existing technology, the assembly of ball screw pairs is mainly done manually, especially the assembly of heavy ball screw pairs. It usually requires two physically strong workers to work together to complete the assembly. The process of inserting the ball nut from the sleeve into the ball screw and removing it from the ball screw into the sleeve requires one person to rotate the ball nut and another person to hold the sleeve. The assembly process is time-consuming and labor-intensive. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a ball screw assembly device to address the shortcomings of the prior art, for assembling a ball screw with a keyway, a ball nut, a return mechanism and multiple steel balls into a ball screw pair. The device includes a screw rotary table, a nut fixing frame and screw pair assembly fixtures.

[0005] A ball screw rotary table is used to fix the ball screw in the vertical direction and drive the ball screw to rotate.

[0006] The nut fixing stand is used to fix the ball nut and adjust its position.

[0007] The tooling for assembling a lead screw assembly includes a sleeve, a sleeve cover, and an anti-rotation bar.

[0008] The sleeve is fixedly installed on the ball screw by a key and a keyway. The sleeve cover is installed on the sleeve, and the sleeve cover and the sleeve can rotate relative to each other.

[0009] The anti-rotation strip is detachably fixed between the sleeve cover and the ball nut. When the ball screw and the sleeve rotate together, the sleeve cover remains stationary relative to the ball nut.

[0010] The sleeve cover has a steel ball outflow channel extending from the upper surface of the sleeve cover to the bottom side of the sleeve cover. The steel ball can flow in from the steel ball inlet on the upper surface of the sleeve cover and flow out from the steel ball outlet at the bottom side of the sleeve cover under the action of gravity. The return device is fixedly installed on the ball nut. The nut fixing frame drives the ball nut to be sleeved on the sleeve cover from top to bottom, and the steel ball outflow outlet is aligned with the groove of the return groove of the return device.

[0011] When the ball screw is driven to rotate in the forward direction by the ball screw rotary table, the steel balls can flow out from the ball outlet under the action of gravity and enter the return device through the slot, and enter the thread channel of the ball nut as the ball screw rotates.

[0012] In one possible implementation, the ball screw rotary table includes a motor, a transmission structure, and a chuck; the output end of the motor is connected to the input end of the transmission structure, and the output end of the transmission structure is connected to the chuck; the chuck is used to clamp and fix the ball screw in the vertical direction; the motor is used to drive the chuck to rotate, thereby driving the ball screw to rotate.

[0013] In one possible implementation, the nut fixing platform includes a platform body, a mounting plate, and a ground slide rail. The ground slide rail is fixed to the ground corresponding to the fixed position of the lead screw rotary table. The platform body is slidably connected to the ground slide rail. Vertical position adjustment mechanisms are provided on both inner sides of the platform body. The mounting plate is fixedly connected to the vertical position adjustment mechanisms, and the ball nut is detachably fixedly connected to the mounting plate. The ground slide rail is used to adjust the horizontal position of the platform body, thereby adjusting the horizontal position of the ball nut. The vertical position adjustment mechanism is used to adjust the vertical position of the mounting plate, thereby adjusting the vertical position of the ball nut.

[0014] In one possible implementation, a torque sensor is provided in the nut fixing stand; the torque sensor is used to detect and display the torque on the ball nut in the radial rotation direction.

[0015] The present invention also provides a method for assembling a ball screw pair, applicable to a ball screw pair assembly device as described in any of the possible implementations above, the method comprising: The nut fixing stand drives the ball nut to be fitted onto the sleeve cover from top to bottom.

[0016] When the ball screw is driven to rotate in the forward direction by the ball screw rotary table, the steel balls flow out from the ball outlet under the action of gravity and enter the return device through the slot, and then enter the thread channel of the ball nut as the ball screw rotates.

[0017] In one possible implementation, the reversing device has multiple rows of reversing grooves, each row of reversing grooves corresponding to a lead. When the ball screw is driven to rotate in the forward direction by the screw rotary table, the steel balls flow out from the steel ball outlet under the action of gravity and enter the reversing device through the groove, and enter the thread channel of the ball nut as the ball screw rotates. Specifically, the reversing device includes the following: When the ball screw is driven to rotate in the forward direction by the ball screw rotary table, the steel balls flow out from the ball outlet under the action of gravity and enter the return device through the target slot aligned with the ball outlet. They then rotate with the ball screw and enter the thread channel of the ball nut to complete the installation within the lead corresponding to the target slot.

[0018] Compared with the prior art, the present invention has the following advantages: The ball screw assembly device of the present invention includes a screw rotary table, a nut fixing frame, and a screw assembly fixture. The screw rotary table is used to fix the ball screw in the vertical direction and drive the ball screw to rotate. The nut fixing frame is used to fix the ball nut and adjust its position. The screw assembly fixture includes a sleeve, a sleeve cover, and an anti-rotation strip. The sleeve is fixedly installed on the ball screw by a key and a keyway, and the sleeve cover is installed on the sleeve, allowing the sleeve cover and the sleeve to rotate relative to each other. The anti-rotation strip is detachably fixed between the sleeve cover and the ball nut, ensuring that the sleeve cover remains stationary relative to the ball nut when the ball screw and the sleeve rotate together. The sleeve cap has a steel ball outflow channel extending from the upper surface of the sleeve to the bottom side of the sleeve. Steel balls flow in from the steel ball inlet on the upper surface of the sleeve and out from the steel ball outlet at the bottom side of the sleeve under gravity. A return mechanism is fixedly mounted on the ball nut. A nut fixing frame drives the ball nut to be fitted onto the sleeve cap from top to bottom, with the steel ball outlet aligned with the return groove of the return mechanism. When the ball screw is driven to rotate forward by the screw rotary table, steel balls flow out from the steel ball outlet under gravity, enter the return mechanism through the groove, and then enter the threaded path of the ball nut as the ball screw rotates. This invention simplifies the complex manual assembly process into simple clamping and starting actions, greatly shortening the assembly time of the ball screw by-product and improving assembly efficiency.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is one of the structural schematic diagrams of a ball screw assembly device according to the present invention; Figure 2 This is a second structural schematic diagram of a ball screw assembly device according to the present invention; Figure 3 This is the third structural schematic diagram of a ball screw assembly device according to the present invention; Figure 4 This is a schematic diagram of the sleeve cover and cover structure of a ball screw assembly device according to the present invention; Figure 5 This is the fourth schematic diagram of the sleeve cover and nut position structure of a ball screw assembly device according to the present invention; Figure 6 This is the fifth structural schematic diagram of a ball screw assembly device according to the present invention; Figure 7 This is a sixth schematic diagram of the structure of a ball screw assembly device according to the present invention; Figure 8 This is a schematic diagram of the screw rotary table structure of a ball screw pair assembly device according to the present invention. Figure 9This is a schematic diagram of the vertical position adjustment mechanism of a ball screw assembly device according to the present invention. Figure 10 This is one of the flowcharts illustrating a ball screw assembly method according to the present invention; Figure 11 This is a second schematic diagram of a ball screw assembly method according to the present invention.

[0021] Explanation of reference numerals in the attached figures: Detailed Implementation

[0022] like Figures 1 to 9 As shown, the ball screw assembly device is used to assemble a ball screw 01 with a keyway, a ball nut 02, a return mechanism 03 and multiple steel balls 04 into a ball screw pair. The device includes a screw rotary table 05, a nut fixing stand 06 and a screw pair assembly fixture 07.

[0023] The ball screw rotary table 05 is used to fix the ball screw 01 in the vertical direction and drive the ball screw 01 to rotate.

[0024] The nut fixing stand 06 is used to fix the ball nut 02 and adjust the position of the ball nut 02.

[0025] The lead screw assembly fixture 07 includes a sleeve 71, a sleeve cover 72, and an anti-rotation strip 73.

[0026] The sleeve 71 is fixedly installed on the ball screw 01 by a key and a keyway. The sleeve cover 72 is installed on the sleeve 71, and the sleeve cover 72 and the sleeve 71 can rotate relative to each other.

[0027] The anti-rotation strip 73 is detachably fixed between the sleeve cover 72 and the ball nut 02. When the ball screw 01 and the sleeve 71 rotate together, the sleeve cover 72 remains stationary relative to the ball nut 02.

[0028] like Figure 4 As shown, the sleeve cover 72 has a steel ball outflow channel extending from the upper surface of the sleeve cover 72 to the bottom side of the sleeve cover 72. The steel ball 04 can flow in from the steel ball inlet 721 on the upper surface of the sleeve cover 72 and flow out from the steel ball outlet 722 at the bottom side of the sleeve cover 72 under the action of gravity. The return device 03 is fixedly installed on the ball nut 02. The nut fixing frame 06 drives the ball nut 02 to be sleeved on the sleeve cover 72 from top to bottom. The steel ball outlet 722 is aligned with the slot of the return groove of the return device 03.

[0029] When the ball screw 01 is driven to rotate in the forward direction by the ball screw rotary table 05, the steel ball 04 can flow out from the steel ball outlet 722 under the action of gravity and enter the return device 03 through the slot, and enter the thread channel of the ball nut 02 as the ball screw 01 rotates.

[0030] In this embodiment, the complex manual assembly process is simplified into simple clamping and starting actions, which greatly shortens the assembly time of the ball screw by-product and improves assembly efficiency. In addition, this device has a reliable clamping mechanism, eliminating the need for back-and-forth handling of the workpiece and avoiding scratches, bumps, slippage, and other damage during the assembly process. This reduces the scrap rate and rework rate, saves considerable costs, and significantly reduces the safety risk of personnel injury from falling objects.

[0031] In one possible implementation, such as Figure 8 As shown, the ball screw rotary table 05 includes a motor 51, a transmission structure 52, and a chuck 53. The output end of the motor 51 is connected to the input end of the transmission structure 52, and the output end of the transmission structure 52 is connected to the chuck 53. The transmission structure 52 can be a gearbox. The chuck 53 can be a claw-type clamping mechanism, such as a three-jaw chuck, which is used to clamp and fix the ball screw 01 in the vertical direction. The motor 51 is used to drive the chuck 53 to rotate, thereby driving the ball screw 01 to rotate.

[0032] In one possible implementation, such as Figure 1 , Figure 2 As shown, the nut fixing stand 06 includes a stand body 61, a mounting plate 62, and a ground slide rail 63. The ground slide rail 63 is fixed to the ground corresponding to the fixed position of the screw rotary table 05. The stand body 61 is slidably connected to the ground slide rail 63. Vertical position adjustment mechanisms 611 are provided on both inner sides of the stand body 61. The mounting plate 62 is fixedly connected to the vertical position adjustment mechanism 611, and the ball nut 02 is detachably fixedly connected to the mounting plate 62. The ground slide rail 63 is used to adjust the horizontal position of the stand body 61, thereby adjusting the horizontal position of the ball nut 02. The vertical position adjustment mechanism 611 is used to adjust the vertical position of the mounting plate 62, thereby adjusting the vertical position of the ball nut 02. The vertical position adjustment mechanism 611 can be a ball screw adjustment structure.

[0033] In this embodiment, the ball screw is mounted on the chuck 53 with its shaft fixed, and the ball nut 02 is mounted on the mounting plate 62. The ball nut 02 can be fixed with a positioning pin to ensure accurate center positioning of the ball nut 02 in the left-right direction. The nut fixing stand 06 can move freely in the front-back direction. During installation, the tooling can be precisely guided and positioned by the rotation of the entire circle of steel balls, ensuring that the ball nut 02 can be screwed into the ball screw 01 smoothly and without deviation, avoiding jamming, abnormal noise, or loss of precision due to misalignment.

[0034] In one possible implementation, such as Figure 2As shown, a torque sensor 64 can also be installed in the nut fixing stand 06. The torque sensor 64 is used to detect and display the torque on the ball nut 02 in the radial rotation direction.

[0035] Specifically, the torque sensor 64 includes two torque sensor probes and a display screen. One torque sensor probe is mounted at each of the two elongated holes on the mounting plate 62. When the ball screw 01 rotates forward and reverse, the two torque sensor probes transmit the force torque signal and display it on the display screen.

[0036] In this embodiment, the torque sensor 64 can measure the preload, avoiding the problem of inconsistent preload determined by feel during manual assembly. Simultaneously, this embodiment ensures that the assembly process and quality of each ball screw are completely consistent, and the number of steel balls assembled in each cycle is consistent, reducing product quality fluctuations caused by differences in manual operation.

[0037] This invention also provides a method for assembling ball screw pairs, applicable to ball screw pair assembly devices as described in any of the possible implementations above, such as... Figure 10 As shown, the method includes: S01, The nut fixing frame drives the ball nut to be fitted onto the sleeve cover from top to bottom; S02. When the ball screw is driven to rotate in the forward direction by the ball screw rotary table, the steel balls flow out from the ball outlet under the action of gravity and enter the return device through the slot, and enter the thread channel of the ball nut as the ball screw rotates.

[0038] In one possible implementation, the reverser has multiple rows of reverse slots, each row of reverse slots corresponding to a lead, such as... Figure 11 As shown, step S2 above specifically includes: S21. When the ball screw is driven to rotate in the forward direction by the ball screw rotary table, the steel ball flows out from the ball outlet under the action of gravity and enters the return device through the target slot aligned with the ball outlet. It then rotates with the ball screw and enters the thread channel of the ball nut to complete the installation within the lead corresponding to the target slot.

[0039] To further understand the present invention, the following provides further supplementary explanation of the method of using the ball screw assembly device of the present invention.

[0040] Step 1: Installation and debugging of the ball screw assembly device: First, fix the lead screw rotary table 05 in the selected position and secure it firmly with anchor bolts.

[0041] Before assembly, inspect and clean the chuck 53 on the ball screw rotary table 05, and fix the previously assembled ball screw pair onto the chuck 53. Start the rotation button of the ball screw rotary table 05 to ensure that the ball screw rotary table 05 can drive the ball screw pair to rotate at a uniform speed clockwise and counterclockwise.

[0042] Next, push the nut fixing stand 06 along the ground slide rail 63 to the ball screw pair position. Use the vertical position adjustment mechanism 611 to adjust the height of the mounting plate 62 so that the mounting plate 62 contacts the bottom surface of the ball nut 02. Loosen the fixing screws on the mounting plate 62, adjust the position of the mounting plate 62, align the two pin holes on the ball nut 02 with the pin holes on the mounting plate 62, and insert the fixing pin, trying to position the fixing pin in the middle of the hole on the mounting plate 62. Then tighten the screws on the mounting plate 62 to ensure that the mounting plate 62 and the nut fixing stand 06 are firmly installed. Use the ball screw rotary table 05 to drive the ball screw to rotate clockwise and counterclockwise, and check the torque data displayed on the torque sensor 64. If the data is abnormal, adjust the mounting plate 62 until the data is normal.

[0043] After debugging, remove the nut fixing stand 06 along the ground slide rail 63, remove the debugging ball screw pair, and begin normal ball screw pair assembly.

[0044] Step 2: Assemble the ball screw assembly. First, check and clean the chuck 53 on the ball screw rotary table 05, and fix the ball screw 01 to be assembled on the chuck 53.

[0045] Then, the sleeve 71 is installed on the ball screw 01, which has a keyway. The sleeve 71 and the ball screw 01 are fixed together with a flat key to prevent them from rotating relative to each other.

[0046] Next, install the sleeve cap 72 onto the sleeve 71. The sleeve cap 72 and sleeve 71 can rotate smoothly. Install the return mechanism 03 onto the ball nut 02 and secure it firmly with special adhesive. Fix the ball nut 02 to the mounting plate 62 with a fixing pin. Push the nut fixing stand 06 along the ground slide rail 63 to the top position of the ball screw 01. Adjust the height of the ball nut 02 using the vertical position adjustment mechanism 611 so that the ball nut 02 fits onto the sleeve cap 72 from top to bottom. Rotate the sleeve cap 72 so that the steel ball outlet 722 is aligned with the groove opening of the bottom row of return grooves of the return mechanism 03. Note that the bottom row of return grooves of the return mechanism 03 should be aligned first, and the assembly should proceed from bottom to top, row by row. Install the anti-rotation strip 73 to ensure that the sleeve cap 72 does not rotate relative to the ball nut 02 when the ball screw 01 and sleeve 71 rotate together.

[0047] Next, the rotary button on the ball screw rotary table 05 is activated, causing the ball screw 01 to rotate at a constant speed in the forward direction. The steel balls 04 required for assembling a row of ball screws are poured onto the sleeve cover 72. Under the action of gravity, the steel balls 04 flow into the return device 03 through the outlet on the sleeve cover 72, and then enter the thread channel of the ball nut 02 as the ball screw 01 rotates, completing the assembly of a row.

[0048] Finally, at a certain time interval, the vertical position adjustment mechanism 611 drives the ball nut 02 to move downward by one lead distance. At this time, the steel ball outlet 722 on the sleeve cover 72 is aligned with the slot of the second row of return grooves of the return device 03. The same number of steel balls 04 are poured onto the sleeve cover 72. Under the action of gravity, the steel balls 04 enter the return device 03 along the outlet on the sleeve cover 72, and enter the threaded channel of the ball nut 02 as the ball screw 01 rotates, completing the assembly of the second row.

[0049] In this manner, each time the vertical position adjustment mechanism 611 moves the ball nut 02 downward by one lead distance, the same number of steel balls 04 are poured onto the sleeve cover 72, completing one row of assembly, and so on from bottom to top until all rows of assembly are completed.

[0050] Remove the anti-rotation strip, and move the ball nut 02 downwards through the vertical position adjustment mechanism 611 until the lower end face of the ball nut 02 is close to the ball screw 01. Turn off the power to the vertical position adjustment mechanism 611 to put the vertical position adjustment mechanism 611 in a free state.

[0051] At this time, the ball nut 02 presses down on the ball screw 01 under the action of gravity. The rotational movement of the ball screw 01 causes the ball nut 02 to move downward along the axis of the ball screw 01 until it is fully installed on the ball screw 01.

[0052] At this time, press the rotation button on the ball screw rotary table 05 to make the ball screw 01 rotate forward and reverse respectively. Repeat this several times to complete the running-in of the ball nut 02 on the ball screw 01.

[0053] When the ball nut 02 runs up and down, the torque sensor 64 on the mounting plate 62 will detect the preload torque of the ball screw pair and record the torque values ​​when the ball nut 02 moves up and down respectively.

[0054] If the torque is within acceptable limits, the ball screw assembly is complete.

[0055] If the torque is not up to standard, the steel ball 04 needs to be replaced and the assembly reassembled. Rotate the vertical position adjustment mechanism 611 in the opposite direction, while gently pressing down on the sleeve 71 and sleeve cap 72 to prevent upward movement. The ball nut 02 moves upward under the drive of the ball screw 01 until it completely leaves the ball screw 01 and transfers onto the sleeve 71. At this point, turn on the button of the vertical position adjustment mechanism 611, hold the sleeve 71 by hand, and move the ball nut 02 and sleeve 71 upward together until they leave the ball screw 01. The ball nut 02 is caught under the steel ball collector. Pull out the sleeve 71 and retrieve the steel ball 04. Finally, select a steel ball 04 of the appropriate size based on the previous torque test value and reassemble according to the above steps until the torque value is acceptable.

[0056] This invention minimizes the impact of human factors through standardized, precise, and labor-saving assembly tools and processes, enabling high-quality, high-efficiency, and large-scale production of ball screw assemblies, especially heavy-duty ball screw assemblies.

[0057] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A ball screw assembly device for assembling a ball screw with a keyway, a ball nut, a return mechanism, and multiple steel balls into a ball screw assembly, characterized in that, Includes a lead screw rotary table, a nut fixing stand, and lead screw assembly fixtures; The ball screw rotary table is used to fix the ball screw in the vertical direction and drive the ball screw to rotate. The nut fixing stand is used to fix the ball nut and adjust the position of the ball nut; The lead screw assembly tooling includes a sleeve, a sleeve cover, and an anti-rotation bar; The sleeve is fixedly installed on the ball screw by a flat key and a keyway, and the sleeve cover is installed on the sleeve. The sleeve cover and the sleeve can rotate relative to each other. The anti-rotation strip is detachably fixed between the sleeve cover and the ball nut. When the ball screw and the sleeve rotate together, the sleeve cover remains stationary relative to the ball nut. The sleeve cover has a steel ball outflow channel extending from the upper surface of the sleeve cover to the bottom side of the sleeve cover. The steel ball can flow in from the steel ball inlet on the upper surface of the sleeve cover and flow out from the steel ball outlet at the bottom side of the sleeve cover under the action of gravity. The return device is fixedly installed on the ball nut. The nut fixing frame drives the ball nut to be fitted onto the sleeve cover from top to bottom. The steel ball outflow outlet is aligned with the slot of the return groove of the return device. When the ball screw is driven to rotate in the forward direction by the ball screw rotary table, the steel ball can flow out from the ball outlet under the action of gravity and enter the return device through the slot, and enter the thread channel of the ball nut as the ball screw rotates.

2. The ball screw assembly device according to claim 1, characterized in that, The lead screw rotary table includes a motor, a transmission structure, and a chuck. The output end of the motor is connected to the input end of the transmission structure, and the output end of the transmission structure is connected to the chuck. The chuck is used to clamp and fix the ball screw in the vertical direction; The motor is used to drive the chuck to rotate, thereby driving the ball screw to rotate.

3. The ball screw assembly device according to claim 1 or 2, characterized in that, The nut fixing stand includes a stand body, a mounting plate, and a ground slide rail; The ground slide rail is fixed on the ground corresponding to the fixed position of the screw rotary table. The main body of the table is slidably connected to the ground slide rail. The two inner sides of the main body of the table are provided with vertical position adjustment mechanisms. The mounting plate is fixedly connected to the vertical position adjustment mechanisms. The ball nut is detachably fixedly connected to the mounting plate. The ground slide rail is used to adjust the position of the frame body in the horizontal direction, thereby adjusting the position of the ball nut in the horizontal direction; the vertical position adjustment mechanism is used to adjust the position of the mounting plate in the vertical direction, thereby adjusting the position of the ball nut in the vertical direction.

4. The ball screw assembly device according to claim 3, characterized in that, A torque sensor is installed in the nut fixing stand; The torque sensor is used to detect and display the torque applied in the circumferential direction to the ball nut flange hole distribution circle.

5. A method for assembling a ball screw pair, applied to the ball screw pair assembly device as described in any one of claims 1-4, characterized in that, include: The nut fixing frame drives the ball nut to be fitted onto the sleeve cover from top to bottom; When the ball screw rotary table drives the ball screw to rotate in the forward direction, the steel ball flows out from the ball outlet under the action of gravity and enters the return device through the slot, and enters the thread channel of the ball nut as the ball screw rotates.

6. The ball screw assembly method according to claim 5, characterized in that, The return device has multiple rows of return grooves, each row of return grooves corresponding to a lead. When the screw rotary table drives the ball screw to rotate in the forward direction, the steel ball flows out from the steel ball outlet under the action of gravity and enters the return device through the groove, and enters the thread channel of the ball nut as the ball screw rotates. Specifically, it includes: When the ball screw rotary table drives the ball screw to rotate in the forward direction, the steel ball flows out from the ball outlet under the action of gravity and enters the return device through the target slot aligned with the ball outlet. It then rotates with the ball screw and enters the thread channel of the ball nut to complete the installation within the lead corresponding to the target slot.

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