Clamp shaft

Abstract

The embodiment of the utility model provides a clamp shaft which comprises a shaft rod, an inner shaft sleeve is arranged on the shaft rod in a sleeved mode, and at least two bearings are arranged on the two sides of the inner shaft sleeve in a sleeved mode respectively. The bearing is sleeved with an outer shaft sleeve, the bearing is located in the outer shaft sleeve, and the outer shaft sleeve is parallel to the inner shaft sleeve; the two ends of the shaft rod extend out of the two ends of the outer shaft sleeve, the first end of the shaft rod is provided with an annular receding position, and the second end of the shaft rod is provided with a fixing groove sunken towards the axis. The clamp shaft structure has the advantages of excellent precision performance, convenient installation driving characteristic and profound promotion effect on industry development, and shows extremely high technical value and market potential.

Description

Technical Field

[0001] This utility model relates to the field of electric spindle technology, and in particular to a clamping shaft. Background Technology

[0002] With the development of technology, many devices require precision components, especially in fields such as aerospace, precision optical instruments, and high-end electronic manufacturing. High-precision machining has always been one of the bottlenecks restricting industrial development. For example, crystal oscillators used in satellites and chips used in electronic devices are manufactured using processes such as photolithography and etching on silicon wafers, and also include the polishing of optical lenses and mirrors.

[0003] As an important mechanical component in the field of precision machining, the precision of the fixture shaft directly affects the precision of the machining equipment. In some fields that require precision machining, if the precision of the corresponding shaft cannot meet the requirements, it will be impossible to process the corresponding precision components, such as silicon wafers, optical glass, and quartz crystals.

[0004] However, current clamping shafts, due to their inherent structure and other limitations, lack sufficient precision to produce the necessary precision components. For instance, China currently cannot produce optical lenses with large focal lengths, relying primarily on imports. This is mainly because the export of precision equipment is generally restricted internationally, and domestically produced clamping shafts do not meet the required precision for grinding optical lenses. Therefore, this invention proposes a clamping shaft to at least partially address the problems inherent in the prior art. Utility Model Content

[0005] In view of the above problems, the present invention provides a fixture shaft that overcomes or at least partially solves the above problems.

[0006] To address the aforementioned problems, this utility model discloses a clamp shaft, comprising:

[0007] A shaft, on which an inner bushing is fitted, and at least two bearings are fitted on each side of the inner bushing.

[0008] The bearing is fitted with an outer bushing, and the bearing is located inside the outer bushing, and the outer bushing and the inner bushing are kept parallel to each other;

[0009] The two ends of the shaft extend beyond the two ends of the outer bushing, and the first end of the shaft is provided with an annular clearance, and the second end of the shaft is provided with a fixing groove recessed towards the axis.

[0010] Optionally, the shaft, located on both sides of the inner bushing, is fitted with at least one first bearing and / or one second bearing respectively; or, the shaft, located on both sides of the inner bushing, is fitted with at least two first bearings or two second bearings on one side, and at least one first bearing and at least one second bearing on the other side.

[0011] The first bearing is a self-aligning ball bearing, and the second bearing is a deep groove ball bearing.

[0012] Optionally, the shaft has two first bearings and one second bearing fitted at one end near the clearance position, wherein the second bearing is located between the two first bearings; or, the shaft has one first bearing and two second bearings fitted at one end near the clearance position, wherein the first bearing is located between the two second bearings.

[0013] The shaft is fitted with two first bearings or two second bearings on the side closest to the fixing groove.

[0014] Optionally, the shaft is further provided with an extension end located outside the fixing groove, and the extension end is provided with a thread.

[0015] Optionally, the shaft is located on one side of the clearance position, and a disc integral with the shaft is provided at the end of the outer bushing;

[0016] The diameter of the disk is not less than the inner diameter of the outer bushing and not greater than the outer diameter of the outer bushing.

[0017] Optionally, the center of the shaft is a hollow cylinder.

[0018] Optionally, a functional pressure ring is also nested and fixed inside the outer bushing, located on one side of the clearance position;

[0019] The inner side of the functional pressure ring abuts against the outer ring side of the bearing;

[0020] The outer side of the functional pressure ring is provided with an oil seal mounting position, and an oil seal concentric with the functional pressure ring is nested in the oil seal mounting position.

[0021] Optionally, the end of the outer bushing has an annular groove on one side of the fixing groove;

[0022] A rotating disk has an inner protruding ring and an outer protruding ring on one side. The inner protruding ring abuts against the inner ring side of the bearing. The outer protruding ring is embedded in the ring groove but does not connect with the ring groove.

[0023] The embodiments of this utility model have the following advantages:

[0024] An inner bushing is fitted onto a shaft, with at least two bearings fitted on each side of the inner bushing. An outer bushing is fitted around each bearing, with the bearing located inside the outer bushing and the outer bushing parallel to the inner bushing. Both ends of the shaft extend beyond the ends of the outer bushing, with a first end of the shaft having an annular clearance and a second end having a recessed fixing groove. This clamp shaft structure possesses excellent precision performance, convenient installation and driving characteristics, and a profound driving effect on industry development, demonstrating extremely high technical value and market potential. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a clamp shaft provided in one embodiment of the present invention;

[0026] Figure 2 This is an exploded view of a clamp shaft provided in one embodiment of the present invention;

[0027] Figure 3 This is a cross-sectional structural diagram of a clamp shaft provided in one embodiment of the present invention. Detailed Implementation

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Reference Figures 1 to 3 As shown, a clamp shaft of the present invention is illustrated, comprising: a shaft 1 on which an inner bushing 2 is sleeved, and at least two bearings are sleeved on both sides of the inner bushing 2; an outer bushing 3 is sleeved outside the bearings, and the bearings are located inside the outer bushing 3, and the outer bushing 3 and the inner bushing 2 are kept parallel; both ends of the shaft 1 extend beyond the two ends of the outer bushing 3, and the first end of the shaft 1 is provided with an annular clearance 104, and the second end of the shaft 1 is provided with a fixing groove 102 recessed towards the axis.

[0030] The above structure solves the problem of insufficient precision in traditional clamping shafts. The clamping shaft of this application has a center runout and end runout (roundness error) of no more than 0.002 mm, and an error of no more than 1~1.5×10. 3This precision, measured in millimeters, meets the requirements of high-precision grinding machine tools, such as for grinding high-precision, large-diameter telephoto lenses. It plays a crucial role in promoting the development of the domestic precision machining industry. The aforementioned structure employs a nested combination of shaft 1, inner bushing 2, and outer bushing 3, with at least two bearings carefully positioned on both sides of the critical inner bushing, constructing a highly stable shaft support architecture. This fundamentally limits the displacement deviation of the shaft during rotation, ensuring that the shaft maintains a near-ideal rotation axis. This precisely controls the radial runout and end runout (roundness error caused by axial movement) within an extremely small range of no more than 0.002mm. Such superior precision far surpasses that of traditional fixture shafts, providing a solid foundation for high-precision machining tasks. It effectively avoids problems such as machining marks on the workpiece surface and impact on dimensional accuracy due to insufficient spindle precision, ensuring that the machined products achieve near-perfect surface quality and dimensional tolerance requirements.

[0031] In practical applications, it excels in demanding scenarios such as the grinding of high-precision, large-aperture telephoto lenses. Lens processing requires not only extremely high surface accuracy to ensure optical performance, but even minute surface imperfections can cause abnormal light refraction and reflection, thus affecting image quality. This fixture axis, with its ultra-precise runout control, can stably and accurately drive the grinding wheel during lens grinding, achieving fine shaping of the lens surface's micro-contours. It meets the stringent standards of the optical industry for lens curvature accuracy and surface roughness, filling a key technological gap in high-precision fixture axes in the domestic high-end precision optical processing field, and powerfully propelling related industries towards higher levels of precision.

[0032] Through the synergistic effect of the inner and outer bushings and the multi-bearing layout, the shaft is provided with comprehensive and high-strength support, improving the strength, rigidity, and stability of the fixture shaft. Multiple bearings distribute the load, reducing the pressure on individual bearings, lowering the risk of wear, and extending bearing life while ensuring the long-term stable operation of shaft 1. Specifically, the outer bushing 3 remains parallel to the inner bushing 2, further standardizing the bearing installation space and running trajectory, effectively resisting external vibrations, impacts, and other interference factors. This allows the fixture shaft to maintain high-precision operation even in complex industrial machining environments, reducing machining errors caused by environmental factors and improving the consistency and stability of machining quality.

[0033] In one embodiment of this application, the shaft 1, located on both sides of the inner bushing 2, is respectively fitted with at least one first bearing 4 and / or one second bearing 5; wherein the first bearing 4 is a self-aligning ball bearing, and the second bearing 5 is a deep groove ball bearing. Alternatively, the shaft 1, located on both sides of the inner bushing 2, may have at least two first bearings 4 or two second bearings 5 ​​fitted on one side, and at least one first bearing 4 and at least one second bearing 5 fitted on the other side.

[0034] Furthermore, the shaft 1, at one end near the clearance position 104, is fitted with two first bearings 4 and one second bearing 5, wherein the second bearing 5 is located between the two first bearings 4; or, alternatively, the shaft 1, at one end near the clearance position 104, may have one first bearing 4 and two second bearings 5 ​​fitted, wherein the first bearing 4 is located between the two second bearings 5; the shaft 1, on the side near the fixing groove 102, is fitted with two first bearings 4 or two second bearings 5. (Refer to...) Figure 2 and Figure 3 As shown, two first bearings 4 and one second bearing 5 are fitted at one end near the clearance position 104, and two first bearings 4 are fitted at the other end.

[0035] The aforementioned self-aligning ball bearing, serving as the first bearing 4, possesses self-aligning properties, capable of compensating for coaxiality deviations caused by factors such as shaft deflection and installation errors. During the operation of the fixture shaft, due to wear caused by machining processes, assembly procedures, or prolonged use, a certain degree of axial misalignment may occur between the shaft 1 and the inner bushing 2. At this time, the self-aligning ball bearings located on both sides of the inner bushing play a crucial role, dynamically adjusting through their own self-aligning structure to ensure that the shaft can still rotate smoothly, maintaining high rotational accuracy, effectively reducing additional vibration and wear caused by shaft misalignment, and extending the overall service life of the fixture shaft. This is particularly suitable for precision machining scenarios with complex working conditions and high requirements for the dynamic stability of the shaft system.

[0036] The aforementioned second bearing 5 is a deep groove ball bearing, characterized by low friction and high limiting speed, providing smooth rotational support for the shaft. During high-speed operation of the fixture shaft, its low-friction characteristics help reduce energy loss and improve energy utilization, enabling the fixture shaft to operate more efficiently and meet the stringent speed requirements of high-speed cutting, grinding, and other machining processes. Simultaneously, the high limiting speed ensures that the bearing will not fail prematurely due to excessive speed when pursuing higher machining efficiency and increased production capacity, laying the foundation for higher performance expansion of the fixture shaft.

[0037] Through the aforementioned hybrid bearing configuration, specifically through various flexible bearing arrangement methods, such as installing at least one first bearing 4 and / or one second bearing 5 on each side, or installing at least two first bearings 4 or two second bearings 5 ​​on one side and at least one first bearing 4 and at least one second bearing 5 on the other side, the advantages of both self-aligning ball bearings and deep groove ball bearings are fully utilized. This hybrid configuration can be tailored to specific machining requirements, fixture shaft design specifications, and expected service life. For example, in precision optical lens grinding applications requiring extremely high shaft concentricity but with relatively moderate rotational speeds, the configuration of self-aligning ball bearings can be emphasized; while in high-speed milling of metal parts where shaft installation accuracy is guaranteed, appropriately increasing the proportion of deep groove ball bearings can ensure accuracy while achieving high-speed and high-efficiency machining, greatly enhancing the versatility and adaptability of the fixture shaft.

[0038] Through multi-bearing collaborative support, regardless of the specific bearing configuration, the arrangement of multiple bearings on both sides of the inner bushing 2 of shaft 1 further strengthens the support for the shaft. Compared to configurations with a single bearing type or a small number of bearings, multiple bearings share the radial force, axial force, and overturning moment on the shaft, enabling the shaft to maintain a stable rotational state even under complex working conditions such as high speed and heavy load. This reduces problems such as shaft deformation and accelerated bearing wear caused by uneven force distribution, thereby continuously ensuring that the excellent heartbeat and end runout accuracy of the fixture shaft is controlled at a high level of no more than 0.002mm, providing reliable hardware support for high-precision machining. Since different machining tasks may face different working conditions, such as cutting force magnitude, speed range, and vibration environment, the diverse bearing combinations can flexibly cope with these conditions. Self-aligning ball bearings ensure basic accuracy by addressing adverse factors such as installation errors and shaft deflection, while deep groove ball bearings contribute to high-speed stable operation. The two complement each other, enabling the fixture shaft to accurately meet the extremely high precision requirements, such as grinding high-precision, large-diameter telephoto lenses, whether in a laboratory-level precision machining environment or in the relatively noisy and variable working conditions of an industrial site. This consolidates and expands the original fixture shaft's advantageous position in the field of precision machining.

[0039] In one embodiment of this application, the shaft 1 is further provided with an extension end 103 located outside the fixing groove 102, and the extension end 103 is provided with a thread (not shown in the figure). The threaded connection with the fixing groove 102 facilitates connection with a transmission mechanism. For example, it can be connected by a sleeve shaft connection or a gear connection. By placing a fixing block in the fixing groove 102, the fixing block will protrude from the fixing groove 102. The notch in the center of the gear or other connecting member is aligned with the fixing block, and then the gear, transmission wheel, or other connecting member is fixed with screws.

[0040] In one embodiment of this application, the shaft 1 is located on one side of the clearance position 104, and a disk 101 integral with the shaft 1 is provided at the end of the outer bushing 3; the diameter of the disk 101 is not less than the inner diameter of the outer bushing 3 and not greater than the outer diameter of the outer bushing 3. This disk 101 serves two purposes: firstly, it prevents foreign objects from falling into the outer bushing 3, thus affecting its accuracy; secondly, it rotates together with the shaft 1 during rotation.

[0041] In one embodiment of this application, the center of the shaft 1 is a hollow cylinder. Since the shaft is generally rotated during operation, and the shaft 1 is relatively sealed inside the inner bushing 2, especially when rotating at high speed, the heat generated by the shaft 1 is difficult to be released from the surface. The hollow cylinder at the center of the shaft 1 can play a certain role in heat dissipation and can also reduce the overall weight.

[0042] In one embodiment of this application, a functional pressure ring 6 (also called a threaded ring) is nested and fixed inside the outer bushing 3, located on one side of the clearance position 104, for pressing the bearing and fixing the oil seal; the inner side of the functional pressure ring 6 abuts against the outer ring side of the bearing; an oil seal mounting position is provided on the outer side of the functional pressure ring 6, and an oil seal 7 concentric with the functional pressure ring 6 is nested in the oil seal mounting position. At the end of the outer bushing 3, an annular groove is provided on one side of the fixing groove 102; a rotating disk 8 has an inner protruding ring and an outer protruding ring on one side, the inner protruding ring abuts against the inner ring side of the bearing; the outer protruding ring is embedded in the annular groove and does not contact the annular groove. Through the functional pressure ring 6, the oil seal 7, and the rotating disk 8, the bearing and the inner bushing can be stably fixed inside the outer bushing 3, and the rotating disk 8 can rotate with the shaft, preventing the drive device, such as a gear, from contacting the edge of the outer bushing 3 when rotating, while simultaneously protecting the inside of the outer bushing 3.

[0043] In this application, the unique design at both ends of the shaft 1 is ingenious. The annular clearance 104 at the first end provides a standardized and convenient interface for the mechanical connection between the fixture shaft and external equipment. Whether connected to the machine tool's worktable, fixture base, or other auxiliary support structures, it can be quickly and securely installed through simple and adaptable connectors, greatly shortening the equipment assembly and debugging cycle and improving production efficiency. The recessed fixing groove 102 at the second end precisely matches the output end of the drive device, ensuring smooth and efficient power transmission and avoiding problems such as power loss and torsional vibration caused by improper connection. This ensures that the fixture shaft can operate smoothly and at high speed when receiving power, further optimizing the overall machining performance.

[0044] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0045] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0046] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0047] The above provides a detailed description of a clamp shaft provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A clamp shaft, characterized in that, include: A shaft (1) is fitted with an inner bushing (2), which is located on both sides of the inner bushing (2), and at least two bearings are fitted on each side; The bearing is fitted with an outer bushing (3), and the bearing is located inside the outer bushing (3), and the outer bushing (3) and the inner bushing (2) are kept parallel to each other; The two ends of the shaft (1) extend out of the two ends of the outer bushing (3), and the first end of the shaft (1) is provided with an annular clearance (104), and the second end of the shaft (1) is provided with a fixing groove (102) recessed towards the axis.

2. The clamp shaft according to claim 1, characterized in that, The shaft (1) is located on both sides of the inner bushing (2), and is fitted with at least one first bearing (4) and / or one second bearing (5); or, the shaft (1) is located on both sides of the inner bushing (2), with at least two first bearings (4) or two second bearings (5) fitted on one side, and at least one first bearing (4) and at least one second bearing (5) fitted on the other side. The first bearing (4) is a self-aligning ball bearing, and the second bearing (5) is a deep groove ball bearing.

3. The clamp shaft according to claim 2, characterized in that, The shaft (1) has two first bearings (4) and one second bearing (5) fitted at one end near the clearance position (104), wherein the second bearing (5) is located between the two first bearings (4); or, the shaft (1) has one first bearing (4) and two second bearings (5) fitted at one end near the clearance position (104), wherein the first bearing (4) is located between the two second bearings (5); The shaft (1) is fitted with two first bearings (4) or two second bearings (5) on the side of the shaft (102) that is close to the fixing groove (102).

4. The clamp shaft according to claim 1, characterized in that, The shaft (1) is also provided with an extension end (103) located outside the fixed groove (102), and the extension end (103) is provided with a thread.

5. The clamp shaft according to claim 1, characterized in that, The shaft (1) is located on one side of the clearance position (104), and a disc (101) integral with the shaft (1) is provided at the end of the outer bushing (3). The diameter of the disk (101) is not less than the inner diameter of the outer bushing (3) and not greater than the outer diameter of the outer bushing (3).

6. The clamp shaft according to claim 1, characterized in that, The center of the shaft (1) is a hollow cylinder.

7. The clamp shaft according to claim 1, characterized in that, Inside the outer bushing (3), on one side of the clearance position (104), a functional pressure ring (6) is also nested and fixed. The inner side of the functional pressure ring (6) abuts against the outer ring side of the bearing; The outer side of the functional pressure ring (6) is provided with an oil seal mounting position, and an oil seal (7) concentric with the functional pressure ring (6) is nested in the oil seal mounting position.

8. The clamp shaft according to claim 1, characterized in that, The end of the outer bushing (3) has an annular groove on one side of the fixing groove (102); The rotating disk (8) has an inner protruding ring and an outer protruding ring on one side, and the inner protruding ring abuts against the inner ring side of the bearing. The outer protruding ring is embedded in the ring groove but does not contact the ring groove.

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