Connecting structure at roller shaft of three-roller sizing mill

Abstract

The utility model relates to the technical field of metal rolling mills, and discloses a connecting structure at a roll shaft of a three-roll sizing mill, which comprises a roll shaft and a bearing inner sleeve, a coaxial first outer spline section is arranged at the extending end of the roll shaft, and a coaxial first inner spline section is arranged in the bearing inner sleeve. And the first external spline section of the roller shaft is inserted into the bearing inner sleeve and is in spline fit with the first internal spline section. The spline tooth structure can be suitable for most roller shafts, is more convenient to assemble after being improved, can greatly increase the number of the spline teeth, is relatively large in outline of the spline teeth, can effectively resist impact in the rolling process, greatly relieves the problem that the spline teeth are easy to wear, and even can avoid the phenomenon of tooth breakage. Besides, the roller shaft and the bearing inner sleeve are in direct transmission mainly through spline fit, so that a spline cover in the prior art can mainly play a role in connection, the impact on the spline cover is greatly reduced, and the service life of a shaft system is effectively prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of metal rolling mills, and more specifically to a connection structure at the roller shafts of a three-roller sizing mill. Background Art

[0002] At present, high-precision three-roller sizing machines are often used to produce high-quality special steel bars or pipes. The principle of the three-roller sizing machine is to achieve metal rolling through the relative movement of three roller rings. The axes of the three roller rings are staggered at an angle of 120 degrees. Each roller ring is provided with a circular arc. The three arcs on the three roller rings form a circular rolling hole. The three-roller sizing machine has the advantages of high deformation efficiency, low energy consumption, low temperature rolling, uniform cross-section deformation, and improved product performance. Therefore, it is widely used at home and abroad.

[0003] The core part of the three-roller sizing machine is composed of three sets of roll assemblies, which are installed in the frame. The core of each roll assembly includes a roll shaft and a roll ring. One end of the roll shaft needs to extend into the frame and be close to the rolling hole, so this end is usually called the insertion end of the roll shaft. The other end of the roll shaft is generally exposed to the frame, so this end is usually called the exposed end of the roll shaft. The roll ring is set on the outside of the roll ring connecting sleeve, such as Figure 1 As shown, the roller ring connecting sleeve 13 is sleeved on the roller shaft 11 and is close to the insertion end of the roller shaft 11. The roller ring connecting sleeve 13 is provided with a bearing inner sleeve 12 on the side of the insertion end facing the roller shaft 11. The bearing inner sleeve 12 is sleeved on the roller shaft 11, and the bearing inner sleeve 12 is connected to the spline cover 14. A threaded hole is coaxially arranged on the spline cover 14, and a through hole is coaxially arranged on the roller shaft 11. A pull rod 15 is coaxially passed through the through hole of the roller shaft 11, and one end of the pull rod 15 is threadedly locked into the threaded hole of the spline cover 14. The other end of the pull rod 15 is locked with a nut 16 at the exposed end of the roller shaft 11. The insertion end of the roller shaft 11 is coaxially provided with an internal spline, and the spline cover 14 is coaxially provided with an external spline. The internal spline of the roller shaft 11 is meshed with the external spline of the spline cover 14. The roller shaft and the bearing inner sleeve of the three-roller sizing mill in the prior art basically adopt the aforementioned connection structure to cope with the impact force during the rolling process.

[0004] However, in this connection structure, an internal spline is arranged at the insertion end of the roller shaft, which results in a smaller number of spline teeth and a smaller profile of the spline teeth. In addition, the spline cover plays a major transmission role and is subject to greater impact. After a period of use, the internal splines at the insertion end of the roller shaft and the external splines on the spline cover are severely worn, and even tooth breakage may occur. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the utility model provides a connection structure at the roller shaft of a three-roller sizing machine. The utility model achieves the above-mentioned purpose through the following technical solutions.

[0006] A connection structure at the roll shaft of a three-roll sizing machine comprises a roll shaft and a bearing inner sleeve, wherein the extending end of the roll shaft is provided with a coaxial first external spline section, the bearing inner sleeve is provided with a coaxial first internal spline section, and the first external spline section of the roll shaft is used to be inserted into the bearing inner sleeve and spline-matched with the first internal spline section.

[0007] In this solution, the extension end of the roller shaft is provided with an external spline section, and the external spline section is directly spline-matched with the inner sleeve of the bearing, which has basically no effect on other structures and dimensions in the prior art, and can be applied to most roller shafts. After such improvement, assembly is more convenient, and the number of spline teeth can be greatly increased. The profile of the spline teeth is also relatively large, which can effectively resist the impact during the rolling process, greatly reduce the problem of easy wear of the spline teeth, and even avoid the occurrence of broken teeth. In addition, the roller shaft and the inner sleeve of the bearing are directly driven mainly through spline matching, so the spline cover in the prior art can mainly play a connecting role, greatly reducing the impact on the spline cover and effectively improving the life of the shaft system.

[0008] As a further improved structural form, a coaxial first optical axis section is provided on the above-mentioned roller shaft in the direction of the exposed end of the roller shaft and adjacent to the first external spline section, the outer diameter of the first optical axis section is larger than the outer diameter of the tooth tip circle of the first external spline section, and a coaxial first optical hole section is provided on the inner sleeve of the bearing, and the first optical axis section of the roller shaft is used to cooperate with the first optical hole section inserted into the inner sleeve of the bearing. This structural form can improve the assembly accuracy and make the transmission between the roller shaft and the inner sleeve of the bearing more stable.

[0009] As a further improved structural form, the above-mentioned roller shaft and bearing inner sleeve are clamped with axial positioning strip keys at the first optical axis section and the first optical hole section. The positioning strip keys in this structural form have both positioning and transmission functions, and together with the spline, they realize the transmission of the roller shaft and the bearing inner sleeve, which can reduce the wear rate of the spline to a certain extent.

[0010] As a further improved structural form, the above-mentioned connection structure also includes a roller ring connecting sleeve, a rolling bearing, a connecting cover and a pull rod, wherein a second inner spline section and a second light hole section are provided in the roller ring connecting sleeve, and a coaxial second outer spline section is provided on the roller shaft in the direction of the exposed end of the roller shaft and adjacent to the first light shaft section, the tooth root circle diameter of the second outer spline section is larger than the outer diameter of the first light shaft section, the second outer spline section of the roller shaft is used to insert into the roller ring connecting sleeve and cooperate with the second inner spline section spline, and the second light hole section of the roller ring connecting sleeve is used to cooperate and be sleeved on the first On the outside of a smooth shaft section, the step surface formed between the second inner spline section and the second light hole section of the roller ring connecting sleeve is used to abut against the shoulder formed between the second outer spline section and the first smooth shaft section of the roller shaft, the bearing inner sleeve is used to abut against the roller ring connecting sleeve, the rolling bearing positioning sleeve is connected to the outside of the bearing inner sleeve, the connecting cover is arranged at the extended end of the roller shaft, the connecting cover is used to abut against the bearing inner sleeve or the rolling bearing, and the connecting cover is connected to the roller shaft or the bearing inner sleeve by bolts, the tie rod and the connecting cover are threadedly connected, the tie rod passes through the roller shaft and is locked with a nut at the exposed end of the roller shaft. The connecting cover in this structural form is equivalent to replacing the spline cover in the prior art, and there is no need to process external splines on the connecting cover, so that the structure is further simplified.

[0011] Compared with the prior art, the utility model has the following beneficial effects: it has basically no effect on other structures and dimensions in the prior art, and can be applied to most roller shafts. After the improvement, the assembly is more convenient, and the number of spline teeth can be greatly increased. The profile of the spline teeth is also relatively large, which can effectively resist the impact during the rolling process, greatly reduce the problem of easy wear of the spline teeth, and even avoid the occurrence of broken teeth. In addition, the roller shaft and the inner sleeve of the bearing are directly driven mainly through spline matching and positioning bar keys, so that the spline cover in the prior art can mainly play a connecting role, greatly reducing the impact on the spline cover, and effectively improving the life of the shaft system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional schematic diagram of the connection structure at the roller shaft of a three-roller sizing mill in the prior art.

[0013] Figure 2 It is a cross-sectional schematic diagram of the connection structure at the roller shaft of the three-roller sizing mill according to an embodiment of the utility model.

[0014] Figure 3 It is a schematic diagram of the cross-sectional structure of the roller shaft in the embodiment of the utility model.

[0015] Figure 4 It is a schematic diagram of the cross-sectional structure of the roller ring connecting sleeve in the embodiment of the utility model.

[0016] Figure 5 It is a schematic diagram of the cross-sectional structure of the bearing inner sleeve in the embodiment of the utility model.

[0017] Figure 6 It is a schematic cross-sectional structure diagram of the connection cover in the embodiment of the utility model.

[0018] Figure 7 It is a schematic diagram of the structure of the pull rod in the embodiment of the utility model. Implementation

[0019] The utility model is further described below in conjunction with the accompanying drawings. The accompanying drawings are only used for exemplary description and cannot be understood as limiting the present patent. In order to more concisely describe the present embodiment, some parts that are well known to those skilled in the art but not related to the main content of the utility model will be omitted in the accompanying drawings or descriptions. In addition, for the convenience of description, some parts in the accompanying drawings will be omitted, enlarged or reduced, but they do not represent the size or entire structure of the actual product.

[0020] Examples, such as Figure 2 As shown, a connection structure at the roll shaft of a three-roll sizing mill includes a roll shaft 21, a bearing inner sleeve 22, a roll ring connecting sleeve 23, a rolling bearing 24, a connecting cover 25 and a pull rod 26.

[0021] like Figure 3 As shown, the roller shaft 21 is provided with a coaxial first external spline segment 211, a first optical axis segment 212, and a second external spline segment 213 in sequence from the inserted end of the roller shaft 21 to the exposed end of the roller shaft 21. The outer diameter of the first optical axis segment 212 is larger than the outer diameter of the tooth top circle of the first external spline segment 211, and the tooth root circle diameter of the second external spline segment 213 is larger than the outer diameter of the first optical axis segment 212. A coaxial through hole 214 is provided in the roller shaft 21.

[0022] like Figure 4 , Figure 2 and Figure 3 As shown, the roller ring connecting sleeve 23 is provided with a second inner spline section 231 and a second light hole section 232. The second outer spline section 213 of the roller shaft 21 is used to be inserted into the roller ring connecting sleeve 23 and spline-matched with the second inner spline section 231. The second light hole section 232 of the roller ring connecting sleeve 23 is used to be matched and sleeved on the outer side of the first light shaft section 212 of the roller shaft 21. The step surface 233 formed between the second inner spline section 231 of the roller ring connecting sleeve 23 and the second light hole section 232 is used to abut against the shoulder 215 formed between the second outer spline section 213 and the first light shaft section 212 of the roller shaft 21.

[0023] like Figure 5 , Figure 3 and Figure 2As shown, the bearing inner sleeve 22 is provided with a coaxial first light hole section 221 and a first inner spline section 222. The first light shaft section 212 of the roll shaft 21 is used to cooperate with the first light hole section 221 of the bearing inner sleeve 22, and the first outer spline section 211 of the roll shaft 21 is used to insert into the bearing inner sleeve 22 and spline-match with the first inner spline section 222. One end of the bearing inner sleeve 22 is used to abut against the roller ring connecting sleeve 23, that is, Figure 2 The left end of the middle bearing inner sleeve 22 abuts against the roller ring connecting sleeve 23. A radially outwardly protruding circumferential boss 223 is provided on the end of the bearing inner sleeve 22 close to the roller ring connecting sleeve 23. The rolling bearing 24 is sleeved on the outer side of the bearing inner sleeve 22 and positioned by the circumferential boss 223, so that the rolling bearing 24 cannot move toward the roller ring connecting sleeve 23.

[0024] The inner wall of the first light hole section 221 of the bearing inner sleeve 22 is provided with an axial first keyway 224, and the first light axis section 212 of the roll shaft 21 is provided with a second keyway (not shown in the figure) opposite to the first keyway 224, and a positioning bar key (not shown in the figure) is installed in the first keyway 224 and the second keyway. The positioning bar key has both positioning and transmission functions, and can be used together with the spline to realize the transmission of the roll shaft 21 and the bearing inner sleeve 22, and reduce the wear rate of the spline to a certain extent.

[0025] like Figure 2 , Figure 5 , Figure 6 and Figure 7 As shown, the connection cover 25 is coaxially arranged at the insertion end of the roller shaft 21, and the connection cover 25 is used to abut the rolling bearing 24, that is, the rolling bearing 24 is clamped between the circumferential boss 223 and the connection cover 25. The connection cover 25 is connected to the bearing inner sleeve 22 by bolts. The connection cover 25 is provided with a coaxial internal thread blind hole 251. The two ends of the pull rod 26 are respectively provided with external thread segments 261. The pull rod 26 passes through the through hole 214 of the roller shaft 21, and the external thread segment 261 at one end of the pull rod 26 is threadedly matched with the internal thread blind hole 251 of the connection cover 25, and the external thread segment 261 at the other end of the pull rod 26 is threadedly matched with a nut 27, and the nut 27 is locked at the exposed end of the roller shaft 21 to tighten the entire connection structure. The connection cover 25 in this embodiment is equivalent to replacing the spline cover in the prior art, and there is no need to process external splines on the connection cover 25, so that the structure is further simplified.

[0026] In this embodiment, the extension end of the roller shaft 21 is provided with an external spline section, and the external spline section is directly spline-matched with the bearing inner sleeve 22, which has basically no effect on other structures and dimensions in the prior art, and can be applied to most roller shafts. The roller shaft 21 and the bearing inner sleeve 22 have both shaft hole matching and spline matching, which can improve the assembly accuracy and make the transmission between the roller shaft 21 and the bearing inner sleeve 22 more stable. The assembly of this embodiment is more convenient, and the number of spline teeth can be greatly increased. The profile of the spline teeth is also relatively large, which can effectively resist the impact during the rolling process, greatly reduce the problem of easy wear of the spline teeth, and even avoid the occurrence of broken teeth. In addition, the roller shaft 21 and the bearing inner sleeve 22 are directly transmitted mainly through spline matching and positioning bar keys, so that the connecting cover 25 can mainly play a connecting role, greatly reducing the impact on the connecting cover 25, and effectively improving the life of the shaft system.

[0027] The above is only a specific embodiment of the present utility model, but the design concept of the present utility model is not limited thereto. Any non-substantial modifications made to the present utility model using the design concept of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A connection structure at the roller shaft of a three-roll sizing mill, comprising a roller shaft and a bearing inner sleeve, characterized in that: The extending end of the roller shaft is provided with a coaxial first external spline section, the inner sleeve of the bearing is provided with a coaxial first internal spline section, and the first external spline section of the roller shaft is used to be inserted into the inner sleeve of the bearing and spline-matched with the first internal spline section.

2. The connection structure at the roller shaft of the three-roll sizing mill according to claim 1 is characterized in that: A coaxial first optical axis section is provided on the roller shaft in the direction of the exposed end of the roller shaft and adjacent to the first external spline section. The outer diameter of the first optical axis section is larger than the outer diameter of the tooth top circle of the first external spline section. A coaxial first optical hole section is provided on the bearing inner sleeve. The first optical axis section of the roller shaft is used to cooperate with the first optical hole section inserted into the bearing inner sleeve.

3. The connection structure at the roller shaft of the three-roller sizing mill according to claim 2 is characterized in that: The roller shaft and the bearing inner sleeve are provided with axial positioning strip keys at the first optical axis section and the first optical hole section.

4. The connection structure at the roller shaft of the three-roll sizing mill according to claim 2, characterized in that: The roller ring connecting sleeve also includes a roller ring connecting sleeve, a rolling bearing, a connecting cover and a pull rod, wherein a second inner spline section and a second light hole section are arranged in the roller ring connecting sleeve, a coaxial second outer spline section is arranged on the roller shaft in the direction of the exposed end of the roller shaft and adjacent to the first light shaft section, the tooth root circle diameter of the second outer spline section is larger than the outer diameter of the first light shaft section, the second outer spline section of the roller shaft is used to insert into the roller ring connecting sleeve and to be spline-matched with the second inner spline section, the second light hole section of the roller ring connecting sleeve is used to be matched and sleeved on the outside of the first light shaft section of the roller shaft, and the roller ring connecting sleeve is used to be matched and sleeved on the outside of the first light shaft section of the roller shaft. The step surface formed between the second inner spline section and the second light hole section of the sleeve is used to abut against the shoulder formed between the second outer spline section and the first light shaft section of the roll shaft. The bearing inner sleeve is used to abut against the roller ring connecting sleeve. The rolling bearing positioning sleeve is connected to the outside of the bearing inner sleeve. The connecting cover is arranged at the extension end of the roll shaft. The connecting cover is used to abut against the bearing inner sleeve or the rolling bearing, and the connecting cover is connected to the roll shaft or the bearing inner sleeve by bolts. The pull rod and the connecting cover are threadedly connected. The pull rod passes through the roll shaft and is locked with a nut at the exposed end of the roll shaft.

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