A pre-stretched wire rod

Abstract

A pre-stretching screw rod relates to the technical field of screw rod pre-stretching, which comprises a ball screw rod, a fixed end assembly rotatably connected to the fixed end, a pre-stretching end assembly rotatably connected to the pre-stretching end, a bearing seat, a bearing installed in the bearing seat, a bearing sleeve sleeved on the pre-stretching end to lock the ball screw rod in the bearing seat, a rear spacer ring installed in the bearing seat, the rear spacer ring sleeved on the pre-stretching end to press the bearing to lock the bearing in the bearing seat, the rear spacer ring pressing the bearing to lock the position, a first locking nut sleeved on the outer end of the pre-stretching end, the first locking nut being in threaded connection with the pre-stretching end, an adjusting nut installed in the bearing seat and sleeved on the rear spacer ring, the adjusting nut being clamped between the first locking nut and the bearing, one end of the adjusting nut pressing the bearing, the other end of the adjusting nut pressing the first locking nut, the adjusting nut providing dynamic pre-tightening force adjustment, the first locking nut and a second locking nut being fixed through threaded locking, and the pre-tightening force being ensured to be stable for a long time.

Description

Technical Field

[0001] This utility model belongs to the field of lead screw pretensioning technology, specifically a pretensioned lead screw. Background Technology

[0002] Currently, ball screw transmission systems are widely used in CNC machine tools. These systems typically employ dedicated bearing structures at both ends to support the screw and transmit axial loads. Traditional designs often use a bearing configuration with one fixed end and the other floating. The fixed end uses angular contact bearings or deep groove ball bearings to restrict the axial movement of the screw and bears the main load. The floating end uses an axially floating bearing to compensate for thermal expansion caused by temperature changes or assembly errors. While this structure is simple and reliable, it has significant drawbacks. After long-term operation, wear on the screw grooves leads to increased axial clearance, and the floating end cannot actively adjust the preload, resulting in a gradual deterioration of the machine tool's positioning accuracy.

[0003] In recent years, some manufacturers have begun to design pre-stretched structures, but most of them are simple pre-stretches. After a period of use, these pre-stretched structures gradually lose their stretching function and cannot guarantee long-term precision and stability.

[0004] A search revealed that utility model publication CN219521390U discloses a lead screw pretensioning mechanism, comprising an L-shaped fixing plate, a lead screw, an adjusting nut, and a spring. The L-shaped fixing plate is fixed to a base surface. A pretensioning hole is provided in the vertical part of the L-shaped fixing plate, and a bearing assembly is provided inside the pretensioning hole. The end of the lead screw passes through the pretensioning hole and has a threaded section. The spring is sleeved on the threaded section, and the adjusting nut is screwed onto the threaded end, compressing the spring. A rectangular mounting block is connected to the vertical part of the L-shaped fixing plate. The pretensioning hole is located on the mounting block, and limiting blocks are provided on both sides of the mounting block. A notch is provided in the vertical part of the L-shaped fixing plate, and a limiting groove is provided inside the notch. A limiting mechanism is connected between the mounting block and the notch. Pretensioning is performed using the elastic force of the spring, but the elastic force of the spring itself will gradually be lost under long-term compression, causing the floating end to be unable to actively adjust the preload. Summary of the Invention

[0005] To address the problem that existing ball screw drives cannot compensate for ball screw wear, resulting in a loss of accuracy as machine tools are used over time, this invention proposes a pre-tensioned screw to solve the aforementioned problem.

[0006] A pre-tensioned screw includes a ball screw, which includes a fixed end, a rod body, and a pre-tensioned end.

[0007] By using segmented fixed ends and pre-tensioned ends, the axial load is reasonably distributed. The fixed end bears the main load, while the pre-tensioned end adjusts the preload through components to avoid axial clearance caused by thermal expansion or wear.

[0008] Furthermore, the rod body mates with the ball screw nut seat to ensure the linearity of the transmission; the linkage between the fixed end and the pre-tensioned end enables dynamic compensation for screw wear.

[0009] Furthermore, it includes a fixed end assembly, which is rotatably connected to the fixed end;

[0010] Furthermore, it also includes a pre-stretch end assembly, which is rotatably connected to the pre-stretch end. The stretch end assembly includes a bearing housing.

[0011] Furthermore, the bearing is installed in a bearing housing and is sleeved on the pre-tensioned end to lock the ball screw in the bearing housing;

[0012] Furthermore, a rear spacer is installed inside the bearing housing. The rear spacer is fitted onto the pre-tensioned end to press against the bearing and lock it inside the bearing housing.

[0013] Furthermore, the rear spacer presses against the bearing to lock it in position, and the washer distributes the pressure between the bearing and the second locking nut to reduce local wear; the second locking nut further strengthens the bearing fixation and improves stability.

[0014] Furthermore, the bearing housing has a multi-layered structure, including a rear spacer, washer, and second lock nut, which forms redundant constraints to prevent the bearing from shifting or loosening.

[0015] Furthermore, a first locking nut is fitted onto the outside of the pre-stretched end, and the first locking nut is threadedly connected to the pre-stretched end;

[0016] Furthermore, an adjusting nut is installed inside the bearing housing and sleeved with the rear spacer ring. The adjusting nut is clamped between the first locking nut and the bearing. One end of the adjusting nut presses against the bearing, and the other end of the adjusting nut presses against the first locking nut.

[0017] Furthermore, the adjusting nut is clamped between the first locking nut and the bearing, and the preload is finely adjusted through the thread to compensate for wear during long-term use; the oblique hole design of the first locking nut enhances the locking reliability, prevents loosening, and facilitates adjustment.

[0018] Furthermore, the adjusting nut has an inner wall surface formed around the axis of the rear spacer, and the rear spacer has an outer wall surface formed around the axis of the rear spacer. The inner wall surface of the adjusting nut is fitted onto the outer wall surface of the rear spacer.

[0019] Furthermore, the inner wall of the adjusting nut is fitted with the outer wall of the rear spacer to ensure adjustment accuracy; the locking nut uses mechanical locking instead of a spring structure to avoid the problem of spring force attenuation.

[0020] Furthermore, it also includes a second locking nut, which is sleeved on the pre-tensioned end near the rod body and is threadedly connected to the pre-tensioned end;

[0021] Furthermore, washers are installed inside the bearing housing;

[0022] Furthermore, the washer is clamped between the bearing and the second locking nut, with the second locking nut pressing against the bearing through the washer.

[0023] Furthermore, the fixed end assembly includes a motor housing; a bearing is installed inside the motor housing, and the bearing is sleeved on the fixed end to lock the ball screw inside the motor housing;

[0024] Furthermore, the front end cover is fitted onto the fixed end near the rod body, and the front end cover presses against the bearing to lock the bearing inside the motor housing;

[0025] Furthermore, a third locking bolt is fitted onto the fixed end and is threadedly connected to the fixed end;

[0026] Furthermore, the front spacer is clamped between the bearing and the third locking bolt.

[0027] Furthermore, a flexible coupling is connected to the fixed end, and a motor is connected to the flexible coupling. The motor is connected to the motor base by bolts.

[0028] Furthermore, the bearing inside the motor housing cooperates with the front cover to limit the axial displacement of the lead screw; the front spacer isolates the bearing from the third locking bolt to reduce vibration transmission; the flexible coupling connects the motor to absorb transmission shock; the fixed end and the pre-tensioned end form a double-end rigid support, which, combined with the flexible coupling, balances transmission accuracy and impact resistance.

[0029] Furthermore, an inspection port is provided on the upper surface of the motor base, and a cover plate is installed at the inspection port. The inspection port facilitates regular maintenance of the bearings and locking components, reducing downtime; the cover plate's sealing design prevents external contamination, and combined with the adjustable pre-tension structure, achieves a balance between long-term maintainability and precision stability.

[0030] Furthermore, during installation, the fixed end is assembled first: the fixed end of the ball screw is installed in the motor housing through a bearing, and the front end cover is sleeved on the side of the fixed end near the rod body, pressing the bearing to limit the axial displacement of the screw.

[0031] Furthermore, the third locking bolt engages with the front spacer ring to isolate vibration between the bearing and the bolt; the flexible coupling connects the motor to the fixed end, absorbing transmission shock.

[0032] Furthermore, after completing the fixed end assembly, the pre-tensioned end assembly is performed: the pre-tensioned end is inserted into the bearing housing, the bearing is sleeved on the pre-tensioned end, and the rear spacer presses the bearing to lock it.

[0033] Furthermore, the adjusting nut is fitted onto the outer wall of the rear spacer and clamped between the first locking nut and the bearing; by tightening the first locking nut, the adjusting nut is pushed forward to press against the bearing, forming an initial preload.

[0034] Furthermore, the second locking nut engages with the washer to reinforce the axial fixation of the bearing from the other side, thus completing the installation of the pre-stretched end.

[0035] Furthermore, during the operation of the lead screw, the motor drives the ball screw to rotate through the flexible coupling, which in turn causes the ball screw nut seat to move linearly along the rod body.

[0036] Furthermore, the fixed end bears the main axial load, while the pre-tensioned end dynamically adjusts the preload through an adjusting nut and a locking nut assembly, including a first locking nut and a second locking nut.

[0037] Furthermore, when the lead screw expands due to temperature rise, the adjusting nut at the pre-tension end can be slightly adjusted to move backward to release axial pressure; conversely, when wear causes the clearance to increase, the adjusting nut can be tightened to restore the preload.

[0038] The oblique hole of the first locking nut penetrates the inner wall surface. When tightened, it generates a radial contraction force, which increases the friction with the screw thread and prevents loosening.

[0039] The second locking nut uses washers to evenly press the bearing, avoiding localized stress concentration;

[0040] The first locking nut has an inner wall surface formed around the axis of the lead screw, and an oblique hole is opened on the circumferential side surface of the first locking nut, the oblique hole penetrating the inner wall surface.

[0041] It also includes a ball screw nut seat, which is fitted onto the rod body.

[0042] The adjusting nut engages with the outer wall of the rear spacer via its inner wall, enabling precise axial displacement control. When the adjusting nut is turned, it moves along the screw axis, pushing the rear spacer against the inner ring of the bearing. This action transmits the preload force through the bearing to the pre-tension end of the ball screw, causing axial tensile stress in the screw.

[0043] The mechanical path is as follows: adjusting nut, rear spacer, bearing inner ring, pre-tensioned end, and ball screw assembly; the preload ensures that the screw is in a slightly stretched state when not subjected to external load, compensating for potential clearances caused by wear or thermal expansion in the future.

[0044] Furthermore, the first locking nut enhances the locking effect through its angled hole design. When the first locking nut is tightened, its angled hole penetrates the inner wall, causing the nut to contract radially, increasing the contact pressure with the screw thread, thereby preventing loosening through friction.

[0045] Furthermore, the oblique hole design reduces the radial stiffness of the lock nut, generating a self-locking effect under axial preload, thus preventing preload attenuation due to vibration or alternating loads.

[0046] Furthermore, when the lead screw expands due to increased temperature, the axial length of the pre-tensioned end increases. At this time, the adjusting nut can be loosened counterclockwise, allowing the rear spacer to move slightly backward, releasing part of the preload and preventing internal stress concentration caused by excessive tension in the lead screw.

[0047] Furthermore, by adjusting the thread of the nut for fine-tuning, the thermal deformation of the lead screw is dynamically matched to maintain a stable preload.

[0048] Furthermore, after prolonged operation, wear may occur in the screw raceway or bearing raceway, leading to increased axial clearance. In this case, tightening the adjusting nut will push the rear spacer forward, recompressing the bearing and restoring the preload.

[0049] Furthermore, the threaded design of the adjusting nut allows for high-precision displacement adjustment, ensuring that the restoration of preload does not affect the straightness of the lead screw and the transmission accuracy.

[0050] Furthermore, the fixed end is rigidly constrained by the bearing within the motor housing and the front end cover. When the lead screw bears an external axial load, the fixed end bears the main force flow:

[0051] The force transmission path is as follows:

[0052] External load, ball screw nut seat, rod body, fixed end, bearing, front end cover, motor base;

[0053] Furthermore, the fixed end restricts the displacement of the lead screw through the axial stiffness of the angular contact bearing, ensuring the positioning accuracy of the transmission system.

[0054] Furthermore, the pre-stretched end forms redundant constraints through multi-layer components:

[0055] Rear spacer: transmits the preload of the adjusting nut to the bearing, while limiting the radial displacement of the bearing inner ring.

[0056] Washers: Distribute the pressure applied by the second locking nut evenly to prevent localized overload on the outer ring of the bearing.

[0057] Second locking nut: Press the washer from the other side to form a symmetrical lock and prevent the bearing from loosening under bidirectional load.

[0058] Multi-layered constraints disperse stress concentration and improve bearing life; symmetrical locking enhances structural rigidity and resists vibration and impact.

[0059] The buffering effect of flexible couplings:

[0060] The fixed end is connected to the motor via a flexible coupling. Its flexible element absorbs the instantaneous impact during motor startup or commutation, reducing the vibration energy transmitted to the lead screw. The stiffness and damping characteristics of the flexible coupling match the natural frequency of the lead screw system, avoiding resonance.

[0061] The front spacer at the fixed end and the rear spacer at the pre-tensioned end respectively isolate the vibration transmission between the bearing and the locking assembly:

[0062] Front spacer: Located between the bearing and the third locking bolt, it reduces the impact of bolt vibration on the bearing.

[0063] Rear spacer: Its rigid structure blocks the transmission of micro-vibrations of the adjusting nut to the bearing.

[0064] The locking nut and lead screw thread are made of a high-friction coefficient material, which, combined with the radial shrinkage effect of the inclined hole, significantly improves the anti-loosening ability.

[0065] The slanted hole causes the contact pressure between the inner wall of the nut and the screw thread to be unevenly distributed, forming a local "engagement" effect, which further resists loosening.

[0066] The contact angle design of angular contact bearings optimizes the distribution ratio of axial and radial loads. Under preload, the contact area between the bearing raceway and the balls increases, improving load-bearing capacity and stiffness.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] 1. Dynamic preload and mechanical locking: The adjusting nut provides dynamic preload adjustment, and the first locking nut and the second locking nut are locked together by threads. The dual mechanism ensures long-term stability of the preload.

[0069] 2. Redundant constraints are set: the rear spacer, washer and locking nut in the bearing housing form a multi-level pressure distribution, and the front spacer at the fixed end a and the third locking bolt isolate vibration, thus improving the structural rigidity.

[0070] 3. Wear resistance and precision compensation: By periodically adjusting the adjusting nut, wear on the lead screw channel is compensated, avoiding the precision degradation caused by increased clearance at the traditional floating end.

[0071] 4. The segmented lead screw and modular components facilitate disassembly and maintenance; the access panel design reduces maintenance costs. Attached Figure Description

[0072] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0073] Figure 1 This is a three-dimensional structural diagram of a pre-tensioned lead screw;

[0074] Figure 2 A top view of a pre-stretched lead screw;

[0075] Figure 3 for Figure 2 EE section view;

[0076] Figure 4 for Figure 3 Enlarged view of section A in the middle;

[0077] Figure 5 for Figure 3 Enlarged view of section B;

[0078] Figure 6 A three-dimensional structural diagram of the pre-tensioned lead screw structure when the motor is not connected.

[0079] Figure 7 This is a three-dimensional structural diagram of the fixed-end assembly and the tension-end assembly;

[0080] Figure 8 Exploded view of the fixed end assembly and the tensile end assembly;

[0081] Figure 9 This is a three-dimensional structural diagram of the first locking nut;

[0082] Figure 10 Side view of the first locking nut;

[0083] Figure 11 for Figure 10 FF section view;

[0084] Figure 12 This is a flowchart of a pre-tensioned lead screw installation process.

[0085] In the picture:

[0086] 1. Ball screw; 1a. Front end; 1b. Screw body; 1c. Rear end;

[0087] 2. First locking nut; 201. Angled hole;

[0088] 3. Adjusting nut;

[0089] 4. Bearing housing;

[0090] 5. Ball screw nut seat;

[0091] 6. Cover plate;

[0092] 7. Electric motor;

[0093] 8. Front cover;

[0094] 9. Motor mount;

[0095] 10. Bearings;

[0096] 11. Second locking nut;

[0097] 12. Third locking nut;

[0098] 13. Flexible coupling;

[0099] 14. Front partition ring;

[0100] 15. Washers;

[0101] 16. Rear spacer ring. Detailed Implementation

[0102] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0103] The application principle of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0104] Example 1

[0105] like Figure 1-4 As shown, a pre-tensioned screw includes a ball screw 1, which includes a fixed end 1a, a rod body 1b, and a pre-tensioned end 1c.

[0106] By using the segmented fixed end 1a and pre-tensioned end 1c, the axial load is reasonably distributed. The fixed end 1a bears the main load, while the pre-tensioned end 1c adjusts the preload through the assembly to avoid axial clearance caused by thermal expansion or wear.

[0107] The rod body 1b mates with the ball screw nut seat 5 to ensure the linearity of the transmission; the linkage between the fixed end 1a and the pre-tensioned end 1c enables dynamic compensation for screw wear.

[0108] Includes a fixed end assembly, which is rotatably connected to the fixed end 1a;

[0109] It also includes a pre-stretch end assembly, which is rotatably connected to the pre-stretch end 1c. The stretch end assembly includes: a bearing housing 4.

[0110] Bearing 10 is installed in bearing housing 4 and is sleeved on pre-tension end 1c to lock ball screw 1 in bearing housing 4.

[0111] The rear spacer 16 is installed in the bearing housing 4 and is sleeved on the pre-tensioned end 1c to press against the bearing 10 and lock the bearing 10 in the bearing housing.

[0112] The rear spacer 16 presses the bearing 10 into a locked position, and the washer 15 distributes the pressure between the bearing 10 and the second locking nut 11 to reduce local wear; the second locking nut 11 further reinforces the bearing 10 and improves stability.

[0113] The bearing housing 4 has a multi-layer structure, including a rear spacer 16, a washer 15, a second locking nut 11, etc., which form redundant constraints to prevent the bearing from shifting or loosening.

[0114] The first locking nut 2 is sleeved on the outside of the pre-stretch end 1c, and the first locking nut 2 is threadedly connected to the pre-stretch end 1c.

[0115] Adjusting nut 3 is installed inside bearing housing 4 and sleeved with rear spacer 16. Adjusting nut 3 is clamped between first locking nut 2 and bearing 10. One end of adjusting nut 3 presses against bearing 10, and the other end of adjusting nut 3 presses against first locking nut 2.

[0116] The adjusting nut 3 is clamped between the first locking nut 2 and the bearing 10. The preload is finely adjusted by the thread to compensate for wear during long-term use. The oblique hole 201 design of the first locking nut 2 enhances the locking reliability, prevents loosening and facilitates adjustment.

[0117] The adjusting nut 3 has an inner wall surface formed around the axis of the rear spacer 16, and the rear spacer 16 has an outer wall surface formed around the axis of the rear spacer 16. The inner wall surface of the adjusting nut 3 is fitted onto the outer wall surface of the rear spacer 16.

[0118] The inner wall of the adjusting nut 3 is fitted with the outer wall of the rear spacer 16 to ensure adjustment accuracy; the locking nut replaces the spring structure with mechanical locking to avoid the problem of spring force attenuation.

[0119] It also includes a second locking nut 11, which is sleeved on the pre-tension end 1c near the rod body 1b, and the second locking nut 11 is threadedly connected to the pre-tension end 1c;

[0120] Washer 15 is installed inside bearing housing 4;

[0121] The washer 15 is clamped between the bearing 10 and the second locking nut 11, and the second locking nut 11 presses against the bearing 10 through the washer 15.

[0122] Example 2

[0123] like Figure 1-5As shown, a pre-tensioned ball screw includes a fixed end assembly, which includes a motor base 9; a bearing 10 is installed inside the motor base 9, and the bearing 10 is sleeved on the fixed end 1a to lock the ball screw 1 inside the motor base 9;

[0124] The front cover 8 is sleeved on the side of the fixed end 1a near the rod 1b. The front cover 8 presses against the bearing 10 to lock the bearing 10 inside the motor base 9.

[0125] The third locking bolt 12 is sleeved on the fixed end 1a and is threadedly connected to the fixed end 1a.

[0126] The front spacer 14 is clamped between the bearing 10 and the third locking bolt 12.

[0127] The fixed end 1a is connected to a flexible coupling 13, which is connected to a motor 7. The motor 7 is connected to the motor base 9 by bolts.

[0128] The bearing 10 inside the motor housing 9 cooperates with the front cover 8 to limit the axial displacement of the lead screw; the front spacer 14 isolates the bearing 10 from the third locking bolt 12 to reduce vibration transmission; the flexible coupling 13 connects the motor 7 to absorb transmission shock; the fixed end 1a and the pre-tensioned end 1c form a double-end rigid support, which, combined with the flexible coupling 13, balances transmission accuracy and impact resistance.

[0129] An inspection port is provided on the upper surface of the motor base 9, and a cover plate 6 is installed at the inspection port. The inspection port facilitates regular maintenance of the bearing 10 and locking assembly, reducing downtime; the cover plate 6 has a sealing design to prevent external contamination, and combined with the adjustable pre-tension structure, it achieves a balance between long-term maintainability and precision stability.

[0130] Example 3

[0131] like Figure 1-11 As shown, a pre-tensioned screw includes a ball screw 1, which includes a fixed end 1a, a rod body 1b, and a pre-tensioned end 1c.

[0132] By using the segmented fixed end 1a and pre-tensioned end 1c, the axial load is reasonably distributed. The fixed end 1a bears the main load, while the pre-tensioned end 1c adjusts the preload through the assembly to avoid axial clearance caused by thermal expansion or wear.

[0133] The rod body 1b mates with the ball screw nut seat 5 to ensure the linearity of the transmission; the linkage between the fixed end 1a and the pre-tensioned end 1c enables dynamic compensation for screw wear.

[0134] Includes a fixed end assembly, which is rotatably connected to the fixed end 1a;

[0135] It also includes a pre-stretch end assembly, which is rotatably connected to the pre-stretch end 1c. The stretch end assembly includes: a bearing housing 4.

[0136] Bearing 10 is installed in bearing housing 4 and is sleeved on pre-tension end 1c to lock ball screw 1 in bearing housing 4.

[0137] The rear spacer 16 is installed in the bearing housing 4 and is sleeved on the pre-tensioned end 1c to press against the bearing 10 and lock the bearing 10 in the bearing housing.

[0138] The rear spacer 16 presses the bearing 10 into a locked position, and the washer 15 distributes the pressure between the bearing 10 and the second locking nut 11 to reduce local wear; the second locking nut 11 further reinforces the bearing 10 and improves stability.

[0139] The bearing housing 4 has a multi-layer structure, including a rear spacer 16, a washer 15, a second locking nut 11, etc., which form redundant constraints to prevent the bearing from shifting or loosening.

[0140] The first locking nut 2 is sleeved on the outside of the pre-stretch end 1c, and the first locking nut 2 is threadedly connected to the pre-stretch end 1c.

[0141] Adjusting nut 3 is installed inside bearing housing 4 and sleeved with rear spacer 16. Adjusting nut 3 is clamped between first locking nut 2 and bearing 10. One end of adjusting nut 3 presses against bearing 10, and the other end of adjusting nut 3 presses against first locking nut 2.

[0142] The adjusting nut 3 is clamped between the first locking nut 2 and the bearing 10. The preload is finely adjusted by the thread to compensate for wear during long-term use. The oblique hole 201 design of the first locking nut 2 enhances the locking reliability, prevents loosening and facilitates adjustment.

[0143] The adjusting nut 3 has an inner wall surface formed around the axis of the rear spacer 16, and the rear spacer 16 has an outer wall surface formed around the axis of the rear spacer 16. The inner wall surface of the adjusting nut 3 is fitted onto the outer wall surface of the rear spacer 16.

[0144] The inner wall of the adjusting nut 3 is fitted with the outer wall of the rear spacer 16 to ensure adjustment accuracy; the locking nut replaces the spring structure with mechanical locking to avoid the problem of spring force attenuation.

[0145] It also includes a second locking nut 11, which is sleeved on the pre-tension end 1c near the rod body 1b, and the second locking nut 11 is threadedly connected to the pre-tension end 1c;

[0146] Washer 15 is installed inside bearing housing 4;

[0147] The washer 15 is clamped between the bearing 10 and the second locking nut 11, and the second locking nut 11 presses against the bearing 10 through the washer 15.

[0148] The fixed end assembly includes a motor base 9; a bearing 10 is installed inside the motor base 9, and the bearing 10 is sleeved on the fixed end 1a to lock the ball screw 1 inside the motor base 9;

[0149] The front cover 8 is sleeved on the side of the fixed end 1a near the rod 1b. The front cover 8 presses against the bearing 10 to lock the bearing 10 inside the motor base 9.

[0150] The third locking bolt 12 is sleeved on the fixed end 1a and is threadedly connected to the fixed end 1a.

[0151] The front spacer 14 is clamped between the bearing 10 and the third locking bolt 12.

[0152] The fixed end 1a is connected to a flexible coupling 13, which is connected to a motor 7. The motor 7 is connected to the motor base 9 by bolts.

[0153] The bearing 10 inside the motor housing 9 cooperates with the front cover 8 to limit the axial displacement of the lead screw; the front spacer 14 isolates the bearing 10 from the third locking bolt 12 to reduce vibration transmission; the flexible coupling 13 connects the motor 7 to absorb transmission shock; the fixed end 1a and the pre-tensioned end 1c form a double-end rigid support, which, combined with the flexible coupling 13, balances transmission accuracy and impact resistance.

[0154] An inspection port is provided on the upper surface of the motor base 9, and a cover plate 6 is installed at the inspection port. The inspection port facilitates regular maintenance of the bearing 10 and locking assembly, reducing downtime; the cover plate 6 has a sealing design to prevent external contamination, and combined with the adjustable pre-tension structure, it achieves a balance between long-term maintainability and precision stability.

[0155] During installation, the fixed end assembly is performed first: the fixed end 1a of the ball screw is installed in the motor base 9 through the bearing 10, and the front end cover 8 is sleeved on the side of the fixed end 1a near the rod body 1b, pressing the bearing 10 to limit the axial displacement of the screw.

[0156] The third locking bolt 12 engages with the front spacer 14 to isolate the vibration between the bearing 10 and the bolt; the flexible coupling 13 connects the motor 7 to the fixed end 1a to absorb transmission shock.

[0157] After completing the fixed end assembly, the pre-tensioned end assembly is performed: the pre-tensioned end 1c is inserted into the bearing housing 4, the bearing 10 is sleeved on the pre-tensioned end 1c, and the rear spacer 16 presses against the bearing 10 to lock it.

[0158] The adjusting nut 3 is sleeved on the outer wall of the rear spacer 16 and clamped between the first locking nut 2 and the bearing 10; by tightening the first locking nut 2, the adjusting nut 3 is pushed forward to press the bearing 10, forming an initial preload.

[0159] The second locking nut 11 engages with the washer 15 to reinforce the axial fixation of the bearing 10 from the other side, thus completing the installation of the pre-stretched end.

[0160] When the screw is running, the motor 7 drives the ball screw 1 to rotate through the flexible coupling 13, which in turn drives the ball screw nut seat 5 to move linearly along the rod body 1b.

[0161] The fixed end 1a bears the main axial load, while the pre-tensioned end 1c dynamically adjusts the preload through the adjusting nut 3 and the locking nut group, including the first locking nut 2 and the second locking nut 11.

[0162] When the lead screw expands due to temperature rise, the adjusting nut 3 at the pre-tension end 1c can be slightly adjusted to move backward to release axial pressure; conversely, when wear causes the clearance to increase, the adjusting nut 3 can be tightened to restore the preload.

[0163] The inclined hole 201 of the first locking nut 2 penetrates the inner wall surface. When tightened, it generates radial contraction force, which enhances the friction with the screw thread and prevents loosening.

[0164] The second locking nut 11 presses the bearing 10 evenly through the washer 15 to avoid local stress concentration;

[0165] The first locking nut 2 has an inner wall surface formed around the axis of the lead screw 1, and an oblique hole 201 is provided on the circumferential side surface of the first locking nut 2.

[0166] The inclined hole 201 penetrates the inner wall surface.

[0167] It also includes a ball screw nut seat 5, which is fitted onto the rod body 1b.

[0168] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

[0169] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A pre-tensioned lead screw, characterized in that: Includes a ball screw (1), which includes a fixed end (1a), a rod body (1b), and a pre-tensioned end (1c). A fixed end assembly, which is rotatably connected to the fixed end (1a). A pre-stretched end assembly, wherein the stretching end assembly is rotatably connected to the pre-stretched end (1c), and the stretching end assembly includes: a bearing seat (4). The bearing (10) is installed in the bearing housing (4) and is sleeved on the pre-tensioned end (1c) to lock the ball screw (1) in the bearing housing (4); A rear spacer (16) is installed inside the bearing housing (4). The rear spacer (16) is sleeved on the pre-stretched end (1c) to press against the bearing (10) and lock the bearing (10) in the bearing housing. The first locking nut (2) is sleeved on the outside of the pre-stretch end (1c) and the first locking nut (2) is threadedly connected to the pre-stretch end (1c); Adjusting nut (3), the adjusting nut (3) is installed in the bearing seat (4) and sleeved with the rear spacer (16). The adjusting nut (3) is clamped between the first locking nut (2) and the bearing (10). One end of the adjusting nut (3) presses against the bearing (10), and the other end of the adjusting nut (3) presses against the first locking nut (2).

2. The pre-tensioned lead screw according to claim 1, characterized in that: The adjusting nut (3) has an inner wall surface formed around the axis of the rear spacer (16), and the rear spacer (16) has an outer wall surface formed around the axis of the rear spacer (16). The inner wall surface of the adjusting nut (3) is fitted onto the outer wall surface of the rear spacer (16).

3. A pre-tensioned lead screw according to claim 2, characterized in that: It also includes a second locking nut (11), which is sleeved on the pre-tensioned end (1c) near the rod body (1b), and the second locking nut (11) is threadedly connected to the pre-tensioned end (1c); Washer (15), said washer (15) is installed in the bearing housing (4); The washer (15) is held between the bearing (10) and the second locking nut (11), and the second locking nut (11) presses against the bearing (10) through the washer (15).

4. A pre-tensioned lead screw according to claim 1, characterized in that: The fixed end assembly includes a motor mount (9); a bearing (10) is installed inside the motor mount (9), and the bearing (10) is sleeved on the fixed end (1a) to lock the ball screw (1) inside the motor mount (9); The front end cover (8) is sleeved on the fixed end (1a) near the rod body (1b) and presses against the bearing (10) to lock the bearing (10) inside the motor seat (9). The third locking bolt (12) is sleeved on the fixed end (1a) and is threadedly connected to the fixed end (1a); The front spacer (14) is clamped between the bearing (10) and the third locking bolt (12).

5. A pre-tensioned lead screw according to claim 4, characterized in that: The fixed end (1a) is connected to an elastic coupling (13), and the elastic coupling (13) is connected to a motor (7). The motor (7) is connected to the motor base (9) by bolts.

6. A pre-tensioned lead screw according to claim 4, characterized in that: The upper surface of the motor base (9) is provided with an inspection port, and a cover plate (6) is installed at the inspection port.

7. A pre-tensioned lead screw according to claim 1, characterized in that: The first locking nut (2) has an inner wall surface formed around the axis of the ball screw (1), and an oblique hole (201) is provided on the circumferential side surface of the first locking nut (2).

8. A pre-tensioned lead screw according to claim 7, characterized in that: The oblique hole (201) penetrates the inner wall surface.

9. A pre-tensioned lead screw according to claim 1, characterized in that: It also includes a ball screw nut seat (5), which is fitted onto the rod body (1b).

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