Roll live center

Abstract

The utility model relates to the technical field of machine tool accessories, and provides a roller live center which comprises an outer cylinder, the outer cylinder is provided with an installation cavity, the installation cavity is provided with a first step part and a second step part, a first supporting piece is arranged on the first step part, a second supporting piece is arranged on the second step part and abuts against the first supporting piece, and a top shaft is rotationally arranged relative to the outer cylinder. The top shaft is arranged on the first supporting piece and the second supporting piece, the top shaft is provided with a third step part, and the first supporting piece is arranged between the third step part and the first step part. By means of the technical scheme, the problem that in the prior art, the fixing precision of a roller live center is poor in the machining process is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of machine tool accessories, in particular to a live center of a roll. Background Art

[0002] In the field of mechanical processing, especially in high-precision, heavy-load processing procedures such as roll processing, the live center is a key tool component, and its performance and stability directly affect the processing quality and efficiency.

[0003] Traditional live center support structures often suffer from numerous shortcomings. The lack of a clear and precise design for the mounting position of the support components makes them prone to misalignment during operation, failing to provide a stable support base for the jacking shaft. This causes the jacking shaft to vibrate and shake during operation, significantly impacting the live center's rotational accuracy. For example, in some traditional structures, due to inaccurate mounting positions, the jacking shaft cannot consistently maintain alignment with the center axis of the roll during roll machining, leading to increased machining errors and making it difficult to meet high standards for the roll's surface quality and dimensional accuracy.

[0004] In terms of load-bearing capacity, traditional support structure designs are not rational. Individual support components often bear significant pressure and lack effective stress dispersion mechanisms. When subjected to large axial and radial forces, such as in large roll machining, support components are prone to deformation or even damage due to concentrated forces, seriously affecting the service life of the live center and the continuity of machining operations. This not only increases equipment maintenance costs but also leads to low production efficiency.

[0005] Furthermore, the installation and maintenance of traditional live centers are cumbersome and complex. The lack of standardized installation procedures makes it difficult to ensure precision and quality control. Maintenance or replacement of support components often requires time-consuming and labor-intensive disassembly of the equipment, resulting in significant downtime and further impacting production schedules. Therefore, an innovative live center support structure design is urgently needed to address these issues. Utility Model Content

[0006] The utility model provides a live center for a rolling mill, which solves the problem of poor fixing precision of the live center for the rolling mill during the machining process in the related art.

[0007] The technical solution of the utility model is as follows:

[0008] Roll live center, including

[0009] An outer cylinder having a mounting cavity, wherein the mounting cavity has a first step portion and a second step portion,

[0010] a first support member, the first support member being arranged on the first step portion,

[0011] a second support member, the second support member being disposed on the second step portion and abutting against the first support member;

[0012] A top shaft is rotatably arranged relative to the outer cylinder, the top shaft is arranged on the first support member and the second support member, the top shaft has a third step portion, and the first support member is arranged between the third step portion and the first step portion.

[0013] As a further technical solution, the first support member is a radial bearing, the second support member is an angular contact ball bearing, the two sides of the outer ring of the first support member are respectively abutted against the first step portion and the third step portion, and the outer ring of the second support member is respectively abutted against the outer ring of the first support member and the second step portion.

[0014] As a further technical solution, the inner ring of the first support member abuts against the third step portion, the inner ring of the second support member abuts against the first support member, the mounting cavity has a fourth boss portion, and the inner ring of the second support member and the fourth boss portion form a clearance.

[0015] As a further technical solution, it also includes

[0016] A pressing piece is provided on the outer cylinder, and the pressing piece has a pressing portion, and the pressing portion is provided in contact with the first supporting member.

[0017] A sealing cover is provided on the pressing member, and the top shaft passes through the sealing cover.

[0018] A sealing member is provided between the top shaft and the pressing member and is used for sealing between the pressing member and the top shaft.

[0019] As a further technical solution, the top shaft has a top end and a tail end, the tail end has a first mounting portion and a second mounting portion, and further includes

[0020] A third support member and a fourth support member, the top shaft is also arranged on the third support member and the fourth support member, the third support member is located between the first mounting portion and the mounting cavity, and the fourth support member is located between the second mounting portion and the mounting cavity.

[0021] As a further technical solution, the third support member and the fourth support member are both radial bearings.

[0022] As a further technical solution, it also includes

[0023] A spacer is provided on one side of the third support member and abuts against the outer ring of the third support member.

[0024] An elastic member is located between the spacer and the fourth support member, and both side end surfaces of the elastic member are respectively in contact with the spacer and the fourth support member.

[0025] As a further technical solution, the tail end has a limiting hole, the limiting hole is coaxial with the top shaft, and further includes

[0026] A compression pad is pressed on the inner ring of the fourth support member.

[0027] As a further technical solution, the installation cavity has a fifth boss portion, and the fifth boss portion abuts against the outer ring of the third support member.

[0028] As a further technical solution, it also includes

[0029] A clamping nut, wherein the clamping nut thread is arranged in the installation cavity, and the clamping nut has a clamping portion, and the clamping portion abuts against the outer ring of the fourth support member.

[0030] The working principle and beneficial effects of the utility model are as follows:

[0031] In this utility model, the first and second steps of the outer cylinder mounting cavity provide clear mounting locations for the first and second support members, ensuring stability during operation. The first support member is positioned between the third and first steps, tightly fitting the jacking shaft and providing axial support. The second support member abuts the first support member, sharing the load of the jacking shaft and improving support stability and reliability.

[0032] This stable support structure effectively reduces vibration and shaking of the jacking shaft during operation, improving the rotational accuracy and operational stability of the live center. For example, during roll machining, the stable support structure ensures that the jacking shaft and the roll's central axis remain aligned, reducing machining errors and improving the roll's surface quality and dimensional accuracy.

[0033] The combined use of the first and second supports effectively improves the live center's load-bearing capacity. During operations such as roll machining, the top shaft is subjected to significant axial and radial forces. The two supports share these loads, distributing the stress and reducing the force exerted on individual supports, thereby improving the live center's overall load-bearing capacity. This dual-support structure meets the demands of larger roll machining, which requires greater load capacity and stability, ensuring the live center withstands heavy loads without deformation or damage.

[0034] The stepped structure of the outer cylinder allows for more standardized and regular installation of the first and second supports. When assembling the live center, simply position the supports on the steps and then install the jack onto the supports, significantly improving installation efficiency and precision. This standardized installation process also facilitates quality control and inspection, ensuring that the live center assembly meets required quality. During production, the fit between the supports and the steps can be quickly checked, allowing for timely identification and resolution of any issues, thereby improving production efficiency and product quality.

[0035] If maintenance or replacement of the support components is necessary during operation, the stepped structure of the outer cylinder facilitates this. Simply remove the top shaft from the support components and easily replace the first or second support components. This convenient maintenance and replacement method reduces equipment downtime, lowers maintenance costs, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The preferred embodiments will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0037] Figure 1 This is a schematic diagram of the structure of the utility model;

[0038] In the figure: outer cylinder-1, mounting cavity-101, first step portion-102, second step portion-103, fourth boss portion-104, clearance gap-105, fifth boss portion-106, first support member-2, second support member-3, top shaft-4, third step portion-401, first mounting portion-402, second mounting portion-403, limiting hole-404, pressing member-5, sealing cover-6, sealing member-7, third support member-8, fourth support member-9, spacer-10, elastic member-11, tightening nut-12. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without inventive work.

[0040] To simplify the drawings, only the parts relevant to the utility model are schematically shown in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one of the components with the same structure or function is schematically shown or labeled. In this document, "one" not only means "only one" but also "more than one," and "several" includes "two" and "more than two."

[0041] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0042] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0043] Reference Figure 1 , which is the first embodiment of the utility model, proposes a live center of a rolling mill, including an outer cylinder 1, the outer cylinder 1 has a mounting cavity 101, the mounting cavity 101 has a first step portion 102 and a second step portion 103, the first support member 2 is arranged on the first step portion 102, the second support member 3 is arranged on the second step portion 103, and abuts against the first support member 2, the top shaft 4 is rotatably arranged relative to the outer cylinder 1, the top shaft 4 is arranged on the first support member 2 and the second support member 3, the top shaft 4 has a third step portion 401, and the first support member 2 is arranged between the third step portion 401 and the first step portion 102.

[0044] In this embodiment, the first step 102 and second step 103 of the mounting cavity 101 of the outer cylinder 1 provide clear mounting locations for the first and second support members 2 and 3, ensuring stability during operation. The first support member 2 is positioned between the third step 401 and the first step 102, tightly fitting with the top shaft 4 and providing axial support for the top shaft 4. The second support member 3 abuts the first support member 2, sharing the load of the top shaft 4 and improving support stability and reliability.

[0045] This stable support structure effectively reduces vibration and shaking of the top shaft 4 during operation, improving the rotational accuracy and operational stability of the live center. For example, during roll machining, the stable support structure ensures that the top shaft 4 remains aligned with the roll's central axis, reducing machining errors and improving the roll's surface quality and dimensional accuracy.

[0046] The combined use of the first and second supports 2 and 3 effectively improves the live center's load-bearing capacity. During operations such as roll machining, the top shaft 4 is subject to significant axial and radial forces. These loads are shared between the two supports, distributing the stress and reducing the force exerted on individual supports, thereby improving the live center's overall load-bearing capacity. This dual-support structure meets the demands of larger roll machining, which requires greater load capacity and stability, ensuring that the live center withstands significant loads without deformation or damage.

[0047] The stepped structure of the outer cylinder 1 allows for a more standardized and regular installation of the first and second support members 2 and 3. When assembling the live center, simply position the supports on the steps and then install the top shaft 4 on the supports, significantly improving installation efficiency and precision. This standardized installation process also facilitates quality control and inspection, ensuring that the live center assembly meets required quality standards. During production, the fit between the supports and the steps can be quickly checked, allowing for timely identification and resolution of any issues, thereby improving production efficiency and product quality.

[0048] If maintenance or replacement of the support members is necessary during operation, the stepped structure of the outer cylinder 1 facilitates this. Simply remove the top shaft 4 from the support member, and then easily replace the first support member 2 or the second support member 3. This convenient maintenance and replacement method reduces equipment downtime, lowers maintenance costs, and improves production efficiency.

[0049] Furthermore, the first support member 2 is a radial bearing, and the second support member 3 is an angular contact ball bearing. The two sides of the outer ring of the first support member 2 are respectively in contact with the first step portion 102 and the third step portion 401, and the outer ring of the second support member 3 is respectively in contact with the outer ring of the first support member 2 and the second step portion 103.

[0050] In this embodiment, the radial bearings mainly bear radial loads, while the angular contact ball bearings can bear both radial and axial loads. This combination enables the live center to reasonably distribute radial and axial loads to different bearings during operation, thereby improving the service life and operating stability of the bearings. During the roller processing process, the top shaft 4 will be subjected to radial and axial forces from the rollers. The radial bearings can effectively bear radial forces, while the angular contact ball bearings can bear axial forces and, through cooperation with the radial bearings, jointly bear part of the radial load. This optimized load sharing method can reduce the force on a single bearing and reduce the risk of bearing wear and damage.

[0051] The combination of radial bearings and angular contact ball bearings improves the live center's load capacity and precision. The radial bearings provide precise radial support, ensuring the accuracy of radial runout during rotation of the top shaft 4; the angular contact ball bearings provide axial support, ensuring the stability of the top shaft 4 in the axial direction.

[0052] The combination of radial bearings and angular contact ball bearings can adapt to different working conditions and load changes. Whether under heavy load, high speed or complex working environment, this combined support can provide reliable support for the top shaft 4 and ensure the normal operation of the live center.

[0053] Furthermore, the inner ring of the first support member 2 abuts against the third step portion 401 , the inner ring of the second support member 3 abuts against the first support member 2 , the mounting cavity 101 has a fourth boss portion 104 , and the inner ring of the second support member 3 and the fourth boss portion 104 form a clearance gap 105 .

[0054] In this embodiment, the inner ring of the first support member 2 abuts the third step 401 of the top shaft 4, and the inner ring of the second support member 3 abuts the first support member 2. This structural design achieves precise positioning of the top shaft 4. During operation, it effectively reduces radial runout and axial movement of the top shaft 4, improving the rotational accuracy of the live center. During roller machining, high-precision positioning ensures that the top shaft 4 is consistently aligned with the center axis of the roller, reducing machining errors and improving the surface quality and dimensional accuracy of the roller.

[0055] The inner rings of the two support members abut against each other, forming a tight support system, providing stronger support for the top shaft 4. This support stability can effectively reduce the load impact on the top shaft 4 during operation, and improve the working reliability and life of the live center.

[0056] The fourth boss portion 104 of the mounting cavity 101 of the outer cylinder 1 forms a clearance gap 105 with the inner ring of the second support member 3. This design avoids interference problems that may occur during installation. The clearance gap 105 provides a certain amount of space margin for the installation of the second support member 3, making installation more flexible and convenient.

[0057] Furthermore, it also includes a pressing piece 5, which is arranged on the outer cylinder 1. The pressing piece 5 has a pressing portion, which is arranged in contact with the first support member 2. The sealing cover 6 is arranged on the pressing piece 5. The top shaft 4 passes through the sealing cover 6. The sealing piece 7 is arranged between the top shaft 4 and the pressing piece 5 for sealing between the pressing piece 5 and the top shaft 4.

[0058] In this embodiment, the pressing portion of the pressing piece 5 abuts against the first support member 2, providing additional pressing force for the first support member 2. During the operation of the live center, the top shaft 4 will be subjected to various forces, which may cause the support member to loosen or shift. The presence of the pressing piece 5 can effectively prevent this from happening, enhance the stability of the first support member 2, and thereby improve the support stability of the entire live center. During the roller processing process, the cutting force and centrifugal force exerted on the top shaft 4 will be transmitted to the support member. The pressing force of the pressing piece 5 can ensure that the support member always remains in the correct position, provide stable support for the top shaft 4, and ensure the accuracy and stability of the processing process.

[0059] The pressing portion of the pressing member 5 is generally designed to have a larger contact area with the first support member 2, so that the pressing force can be more evenly distributed on the first support member 2. Evenly distributed pressure can reduce local stress concentration, extend the service life of the support member, and also improve the stability and reliability of the support.

[0060] Seal 7, positioned between top shaft 4 and pressure piece 5, effectively prevents foreign matter, such as dust and metal shavings, from entering the live center, while also preventing lubricant leakage. In environments such as roll processing, the ingress of foreign matter could damage components such as the support and top shaft 4, reducing the live center's service life and accuracy. Lubricant leakage, on the other hand, wastes the live center and compromises the working environment. The excellent sealing performance of seal 7 ensures the live center operates properly even in harsh operating environments, enhancing its reliability and stability.

[0061] The combination of sealing cap 6 and seal 7 forms an effective sealing system that protects the components within the live center from environmental influences. Sealing cap 6 prevents external objects from directly impacting seal 7, extending its service life. Furthermore, sealing cap 6 provides a protective barrier, preventing operators from accidentally touching internal components during operation, thus improving work safety.

[0062] Furthermore, the top shaft 4 has a top end and a tail end, the tail end has a first mounting portion 402 and a second mounting portion 403, and also includes a third support member 8 and a fourth support member 9. The top shaft 4 is also arranged on the third support member 8 and the fourth support member 9. The third support member 8 is located between the first mounting portion 402 and the mounting cavity 101, and the fourth support member 9 is located between the second mounting portion 403 and the mounting cavity 101.

[0063] In this embodiment, the addition of third and fourth support members 8 and 9 provides multi-point support for the top shaft 4, enabling it to more stably withstand various loads during operation. In working environments such as roll milling, the top shaft 4 is subject to a variety of forces, including radial force, axial force, and torque from the rolls. Multi-point support effectively distributes these forces, reducing the stress on a single support point and improving the load-bearing capacity and stability of the live center.

[0064] Support members positioned at different locations can accommodate loads in different directions. The first and second support members 2 and 3 primarily bear radial loads and some axial loads, while the third and fourth support members 8 and 9 can handle forces in different directions depending on the actual situation. This multi-point support structure design can better adapt to complex workloads and improve the adaptability and reliability of the live center.

[0065] Multi-point support can reduce the deformation and vibration of the top shaft 4 during operation. In the high-speed rotating roller processing, the deformation and vibration of the top shaft 4 will directly affect the processing accuracy and surface quality. The addition of the third support member 8 and the fourth support member 9 can effectively limit the deformation of the top shaft 4, reduce the generation of vibration, improve the rotation accuracy of the live center, optimize the force distribution of the top shaft 4, and make the shaft more evenly stressed during operation. Uniform force can reduce local stress concentration, extend the service life of the top shaft 4, and also improve the rotation accuracy. For some live centers that work for a long time, optimized force distribution can reduce the risk of fatigue damage and improve the reliability and stability of the equipment.

[0066] Furthermore, the third support member 8 and the fourth support member 9 are both radial bearings.

[0067] In this embodiment, the third and fourth support members 8 and 9 are radial bearings that, together with the radial bearings of the first support member 2, provide strong radial support for the top shaft 4. During the rolling process, the top shaft 4 is subjected to significant radial forces from the rolls. The combined action of multiple radial bearings effectively disperses these forces, improving the radial load-bearing capacity of the live center. These radial bearings offer high precision and stability, ensuring that the radial runout of the top shaft 4 remains within a narrow range during rotation. The synergistic effect of multiple radial bearings further enhances the stability of rotational accuracy and reduces machining errors caused by radial runout.

[0068] Furthermore, it also includes a spacer 10, which is arranged on one side of the third support member 8, and the spacer 10 abuts against the outer ring of the third support member 8. The elastic member 11 is located between the spacer 10 and the fourth support member 9, and the two side end faces of the elastic member 11 abut against the spacer 10 and the fourth support member 9 respectively.

[0069] In this embodiment, the presence of elastic member 11 allows the live center to better adapt to varying loads during operation. When the top shaft 4 is subjected to varying radial and axial forces, the elastic member 11 can adjust the position and force of the top shaft 4 by compressing or expanding, thereby reducing the impact and damage to the support and other components caused by the load changes.

[0070] The elastic member 11 provides a certain degree of cushioning protection for the top shaft 4, reducing damage to the equipment caused by shock and vibration. During operation, the top shaft 4 may be subjected to sudden impact or vibration from the rollers. The elastic member 11 can absorb these impact and vibration energy, reducing the impact on the support and other components.

[0071] The combination of spacer 10 and elastic member 11 adjusts the position of third support member 8 and fourth support member 9, allowing them to better adapt to the force applied to top shaft 4 during operation. By adjusting the thickness of spacer 10 or the elastic modulus of elastic member 11, the preload force and position of the supports can be changed, thereby optimizing the overall performance of the live center.

[0072] The elastic force of the elastic member 11 can balance the force distribution between the third support member 8 and the fourth support member 9 to a certain extent. When the top shaft 4 is subjected to uneven load, the elastic member 11 can adjust the force between the supports by compressing or stretching, making the force more uniform and reducing local stress concentration.

[0073] Furthermore, the tail end has a limiting hole 404 , which is coaxial with the top shaft 4 , and also includes a pressing pad, which is pressed on the inner ring of the fourth support member 9 .

[0074] In this embodiment, a pressure pad is mounted on the inner ring of the fourth support member 9, providing additional pressure and effectively preventing it from loosening or shifting during operation. In environments such as roller processing, the top shaft 4 is subject to various forces, which could cause the support members to loosen, thereby affecting the stability and rotational accuracy of the top shaft 4. The presence of the pressure pad significantly reduces this risk and improves the operational stability of the live center.

[0075] The stability of the fourth support member 9 directly affects the rotational accuracy of the top shaft 4. The compression of the pressure pad reduces axial and radial runout of the fourth support member 9, thereby improving the rotational accuracy of the top shaft 4. In precision roller machining, high rotational accuracy ensures the roller's surface quality and dimensional accuracy, meeting the requirements of high-precision machining.

[0076] Furthermore, the installation cavity 101 has a fifth boss portion 106 , which abuts against the outer ring of the third support member 8 .

[0077] In this embodiment, the fifth boss portion 106 provides clear support and positioning for the third support member 8, enabling it to more stably withstand the load of the top shaft 4 during operation. In working environments such as roller processing, the top shaft 4 is subject to various forces, and the third support member 8 requires stable support to ensure normal operation of the top shaft 4. The presence of the fifth boss portion 106 effectively limits the displacement and shaking of the third support member 8, thereby improving support stability.

[0078] Fifth boss 106 abuts the outer ring of third support member 8, increasing the support area and thereby improving the load-bearing capacity of third support member 8. Under heavy or complex operating conditions, the live center needs to bear a large load. The support provided by fifth boss 106 can share some of this load, reducing the burden on other support members and improving the load-bearing capacity of the entire live center.

[0079] Furthermore, it also includes a clamping nut 12 , which is threadedly disposed in the installation cavity 101 . The clamping nut 12 has a clamping portion that abuts against the outer ring of the fourth support member 9 .

[0080] In this embodiment, the compression portion of the compression nut 12 abuts the outer ring of the fourth support member 9, providing strong clamping force and effectively preventing loosening or displacement of the fourth support member 9 during operation. In working environments such as roller processing, the top shaft 4 is subject to various forces, which may cause the support members to loosen, thereby affecting the stability and rotational accuracy of the top shaft 4. The presence of the compression nut 12 significantly reduces this risk and improves the operational stability of the live center.

[0081] In high-speed roller machining, a stable support structure is crucial for ensuring machining accuracy. The compression nut 12 ensures that the fourth support member 9 remains in the correct position, providing stable support for the top shaft 4 and reducing machining errors. The threaded connection of the compression nut 12 secures it within the mounting cavity 101, providing continuous pressure on the fourth support member 9. This reliable connection enhances the structural strength and reliability of the entire live center, reducing equipment failure and damage caused by loose support members.

[0082] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, and all of these should be included in the scope of the claims of the present invention.

Claims

1. The live center of the roller is characterized by: include An outer cylinder (1), the outer cylinder (1) having a mounting cavity (101), the mounting cavity (101) having a first step portion (102) and a second step portion (103), a first support member (2), the first support member (2) being arranged on the first step portion (102), a second support member (3), the second support member (3) being arranged on the second step portion (103) and abutting against the first support member (2), A top shaft (4), the top shaft (4) being rotatably arranged relative to the outer cylinder (1), the top shaft (4) being arranged on the first support member (2) and the second support member (3), the top shaft (4) having a third step portion (401), and the first support member (2) being arranged between the third step portion (401) and the first step portion (102).

2. The live center of the roller according to claim 1, characterized in that: The first support member (2) is a radial bearing, and the second support member (3) is an angular contact ball bearing. Both sides of the outer ring of the first support member (2) abut against the first step portion (102) and the third step portion (401), respectively. The outer ring of the second support member (3) abuts against the outer ring of the first support member (2) and the second step portion (103), respectively.

3. The live center of the roller according to claim 2, characterized in that: The inner ring of the first support member (2) abuts against the third step portion (401), the inner ring of the second support member (3) abuts against the first support member (2), the mounting cavity (101) has a fourth boss portion (104), and the inner ring of the second support member (3) and the fourth boss portion (104) form a clearance gap (105).

4. The live center of the roll according to claim 1, characterized in that: Also includes A pressing piece (5), the pressing piece (5) is arranged on the outer cylinder (1), the pressing piece (5) has a pressing portion, and the pressing portion is arranged to abut against the first supporting piece (2). A sealing cover (6), wherein the sealing cover (6) is arranged on the pressing piece (5), and the top shaft (4) passes through the sealing cover (6). A sealing member (7) is provided between the top shaft (4) and the pressing member (5) and is used for sealing between the pressing member (5) and the top shaft (4).

5. The live center of the roll according to claim 4, characterized in that: The top shaft (4) has a top end and a tail end, the tail end has a first mounting portion (402) and a second mounting portion (403), and further includes A third support member (8) and a fourth support member (9), the top shaft (4) is also arranged on the third support member (8) and the fourth support member (9), the third support member (8) is located between the first mounting portion (402) and the mounting cavity (101), and the fourth support member (9) is located between the second mounting portion (403) and the mounting cavity (101).

6. The live center of the roller according to claim 5, characterized in that: The third support member (8) and the fourth support member (9) are both radial bearings.

7. The live center of the roll according to claim 5, characterized in that: Also includes A spacer (10), the spacer (10) being arranged on one side of the third support member (8), the spacer (10) being in contact with the outer ring of the third support member (8), An elastic member (11), the elastic member (11) is located between the spacer (10) and the fourth support member (9), and both side end surfaces of the elastic member (11) are in contact with the spacer (10) and the fourth support member (9) respectively.

8. The live center of the roller according to claim 5, characterized in that: The tail end has a limiting hole (404), the limiting hole (404) is coaxial with the top shaft (4), and further includes A compression pad, the compression pad is pressed on the inner ring of the fourth support member (9).

9. The live center of the roll according to claim 5, characterized in that The installation cavity (101) has a fifth boss portion (106), and the fifth boss portion (106) abuts against the outer ring of the third support member (8).

10. The live center of the roll according to claim 9, characterized in that: Also includes A clamping nut (12), wherein the clamping nut (12) is threadedly disposed in the installation cavity (101), and the clamping nut (12) has a clamping portion, and the clamping portion abuts against the outer ring of the fourth support member (9).

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