JP6015380B2 - Universal joint - Google Patents

Description

  The present invention relates to a universal joint provided in a drive shaft of a steel rolling facility or the like.

  In steel rolling equipment, a drive shaft is used to transmit the rotation of a drive motor to a steel rolling roller. This drive shaft is composed of a drive shaft connected to the drive motor side, a driven shaft connected to the steel rolling roller side, and an intermediate shaft connecting the drive shaft and the driven shaft. Has been. These shaft portions are not on the same shaft, and the drive shaft is provided with a universal joint between each shaft portion in order to connect each shaft portion and transmit rotation smoothly.

  The universal joint includes, for example, a cross shaft having raceway surfaces formed on the outer periphery of four shaft portions, a plurality of needle rollers that roll on the raceway surface of the shaft portion, and each shaft portion via the needle rollers. There is a block type provided with a bearing cup that is swingably mounted. In this bearing cup, a key portion protruding toward the yoke side and a bolt insertion hole formed at both side positions of the key portion are formed on the joint surface with the yoke. Then, the key portion is fitted into the key groove formed in the yoke, the bolt is inserted into the bolt insertion hole, and the bearing cup and the yoke are joined and fixed by screwing into the screw hole of the yoke. Yes.

  By the way, in the hot rolling process of the steel rolling equipment, the rolled material is very hot, and cooling water called rolling water is constantly applied to the equipment in order to prevent the temperature rise of the work roll and peripheral equipment. In this way, universal joints used in the drive shafts of steel rolling equipment are subjected to harsh environments that are prone to corrosion in addition to high temperatures and high loads. Corrosion may lead to damage. For example, in Patent Document 1, the key part of the bearing cup is formed with a film having excellent corrosion resistance to improve the corrosion resistance of the key part, and the occurrence of a gap between the key groove and the bolt is excessive. Universal joints that prevent the action of various bending stresses are disclosed.

JP 2006-77873 A

  However, corrosion may corrode not only at the key portion but also around the bolt that joins and fixes the bearing cup and the yoke, and the corrosion around the bolt may cause damage. Since the bolt has a larger thread diameter than the body diameter, and the bolt insertion hole is larger than the thread diameter so that the bolt can be easily inserted, the bolt insertion hole and the bolt body There is a gap between them. Corrosion around the bolt is caused by the rolling water entering from the joint surface between the bearing cup and the yoke (or the bearing cup and the bolt seating surface), and moisture remaining in the gap. For this reason, the boundary between the joint surface of the bearing cup and the yoke is glazed or the like, but there is a problem that the ingress of rolling water cannot be sufficiently prevented for a long period of time. On the other hand, the intrusion prevention measure in which a seal member such as an O-ring is disposed on the joint surface between the bearing cup and the yoke has a problem in that it affects torque transmission because the area of the joint surface is reduced. Also, in regular maintenance of steel rolling equipment, the drive shaft and universal joint are removed and inspected. At that time, since the bolt which is an important part is subjected to nondestructive inspection, it is desired that the bolt can be removed and no foreign matter hindering the nondestructive inspection is attached.

  The present invention has been made to solve the above-mentioned problems, and the problem to be solved by the present invention is to be used in a high load and corrosive environment such as a drive system of a rolling mill for steel. Another object of the present invention is to provide a universal joint that does not corrode around the bearing cup fixing bolt and can exhibit stable performance over a long period of time.

  The invention according to claim 1 is a cross shaft in which raceway surfaces are formed on the outer periphery of four shaft portions, a plurality of rolling elements that roll on the raceway surface of the shaft portion, and each of the shafts via the rolling members. A bearing cup that is swingably attached to the portion, wherein the bearing cup protrudes toward the yoke side on a joint surface with the yoke, and bolt insertions formed at both side positions of the key portion. The key portion is fitted into a key groove formed in the yoke, a bearing fixing bolt is inserted into the bolt insertion hole, and is screwed into a screw hole of the yoke, and is joined to the yoke. In the fixed universal joint, a plurality of through holes extending from the bolt insertion hole to the outer peripheral side end portion of the bearing cup are formed, and the through hole is an opening portion of the outer peripheral surface of the bearing cup. The opening is sealed in a state where the grease injected from the opening is filled in the gap between the bearing fixing bolt and the bolt insertion hole through the through hole. And

  According to the invention of claim 1 configured as described above, in assembling the universal joint, after the bearing cup and the yoke are joined and fixed by the bearing fixing bolt, the grease injected from the opening portion is inserted into the bearing through the through hole. The opening is sealed in a state where the gap between the fixing bolt and the bolt insertion hole is filled. Thereby, since rolling water cannot permeate into the gap between the bearing fixing bolt and the bolt insertion hole, corrosion around the bearing fixing bolt due to moisture remaining in the gap can be prevented. In addition, since the joint area and joint strength between the bearing cup and the yoke are not different from the conventional one, the torque transmission is not affected. Further, the bearing fixing bolt can be removed, and when it is removed, no foreign matter that obstructs the nondestructive inspection is attached, so that maintenance can be easily performed.

  The invention according to claim 2 is the universal joint according to claim 1, wherein the hole diameter of the bolt insertion hole is larger than the thread diameter of the bearing fixing bolt, and the bearing fixing bolt has a trunk diameter. An annular guide portion that is smaller than the screw portion diameter and guides the barrel portion to be positioned at the center of the bolt insertion hole in a state where the bearing fixing bolt is inserted into the bolt insertion hole. Universal joints characterized by having at one end or both ends.

  According to the invention of claim 2 configured as described above, when the bearing fixing bolt is inserted into the bolt insertion hole by the annular guide portions at one end or both ends of the body portion of the bearing fixing bolt, It is possible to guide so that the body portion is positioned at the center of the bolt insertion hole. By positioning the body portion of the bearing fixing bolt at the center of the bolt insertion hole, a gap can be reliably formed between the body portion and the bolt insertion hole. As a result, the injected grease can be uniformly filled around the body portion, so that moisture and the like can be prevented from entering the gap over a long period of time.

  According to the present invention, the bearing cup fixing bolt periphery does not corrode even when used in a high load and corrosive environment such as a drive system of a rolling mill for steel, and can exhibit stable performance over a long period of time. Joints can be provided.

It is a perspective view of the drive shaft provided with the universal joint which concerns on embodiment of this invention. It is explanatory drawing of the drive shaft to which a drive motor and the rolling roller for steel are connected. It is a principal part disassembled perspective view of the conventional block type universal joint. It is a partial cross section figure of the universal joint which concerns on embodiment of this invention. It is AA sectional drawing of FIG.

Hereinafter, a universal joint according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the universal joint 1 which concerns on embodiment of this invention is used for the drive shaft D of the rolling mill for steel. The drive shaft D is for connecting a steel rolling roller and a drive motor (both not shown), and transmits the rotation of the drive motor to the steel rolling roller.

  In a steel rolling facility (not shown), two drive shafts D are arranged in parallel, and a slab (not shown) is provided between two steel rolling rollers connected to the drive shafts D. The steel material (not shown) by which the rolling process was performed is manufactured by letting it pass.

  As shown in FIGS. 1 and 2, the drive shaft D includes a drive shaft portion D1 connected to the drive motor side, a driven shaft portion D2 connected to the steel rolling roller side, a drive shaft portion D1, and a driven shaft portion. It is comprised from the intermediate shaft part D3 which connects between D2.

  The drive shaft portion D1 and the intermediate shaft portion D3, and the driven shaft portion D2 and the intermediate shaft portion D3 are connected via the universal joint 1, respectively. Therefore, as shown in FIG. 2, even if the rotation center line A1 of the steel rolling roller does not coincide with the rotation center line A2 of the drive motor, the rotation of the drive motor is transmitted to the steel rolling roller. Further, the intermediate shaft portion D3 of the drive shaft D rotates while maintaining a state in which it is inclined with respect to the horizontal direction H.

  As shown in FIG. 3, the universal joint 1 includes a cross shaft 10 having four shaft portions 11, a plurality of needle rollers 20 that roll on the raceway surface of the shaft portion 11, and the needle rollers 20. The block type includes a bearing cup 30 that is swingably attached to the shaft portion 11.

  The drive shaft portion D1, the intermediate shaft portion D3, and the universal joint 1 are configured to join and fix the bearing cup 30 and the yoke 40 via the yoke 40 of each shaft portion. The universal joint 1 connected to the driven shaft portion D2 and the intermediate shaft portion D3 has the same configuration.

  As shown in FIG. 4, the universal joint 1 includes a cross shaft 10 having four shaft portions 11, needle rollers 20 attached to the four shaft portions 11, a bearing cup 30, and the like.

  The cross shaft 10 is formed into a cross shape by four shaft portions 11, and includes a body portion 12 and four columnar shaft portions 11 protruding radially outward from the body portion 12. On the outer periphery of the shaft portion 11, a raceway surface 14 is formed on which the needle rollers 20 that are rolling elements roll.

  The bearing cup 30 is formed in a fan-like shape as a whole. The bearing cup 30 is swingably attached to the shaft portion 11 via the needle rollers 20. A gap S is formed between the bearing cup 30 attached to each shaft portion 11 of the cross shaft 10 and the bearing cup 30 adjacent in the circumferential direction.

  Each of the four shaft portions 11 of the cross shaft 10 is covered with a bearing cup 30, and the cross shaft 10 is incorporated in the drive shaft D with almost no exposure to the outside. The bearing cup 30 attached to each shaft portion 11 is a swinging member that is swingably attached to the shaft portion 11, and the bearing cup 30 swings about the axis of the shaft portion 11. Can do.

  In addition, the bearing cup 30 is formed with a cylindrical recess 32 that opens to the inner peripheral end surface 31 in order to accommodate the shaft portion 11 via the needle rollers 20. A raceway surface 34 on which the needle rollers 20 roll is formed on the inner periphery 33 of the cylindrical recess 32.

  FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4. As shown in FIG. 5, the bearing cup 30 is formed with a key portion 38 that protrudes toward the yoke 40 on the joint surface with the yoke 40. . Bolt insertion holes 39 through which the bearing fixing bolts 50 are inserted are formed at both side positions of the key portion 38.

  The bearing fixing bolt 50 includes a head portion 51, a body portion 52, and a screw portion 53, and has an annular guide portion 54 at one end of the body portion 52. Further, the diameter of the body portion of the bearing fixing bolt 50 is smaller than the diameter of the screw portion, and the hole diameter of the bolt insertion hole 39 is larger than the diameter of the screw portion so that the bolt can be easily inserted during assembly. The guide portion 54 guides the body portion 52 so as to be positioned at the center of the bolt insertion hole 39 in a state where the bearing fixing bolt 50 is inserted into the bolt insertion hole 39. Since the body portion 52 of the bearing fixing bolt 50 is positioned at the center of the bolt insertion hole 39, a gap d is formed between the body portion 52 and the bolt insertion hole 39.

  As shown in FIG. 5, through holes 36 extending to the outer peripheral side end 35 of the bearing cup 30 are formed in the bolt insertion hole 39 at two locations on the bolt head side and the screw portion side. The through hole 36 communicates with the gap d and the opening 36 a of the outer peripheral surface 37 of the bearing cup 30. A screw groove is formed in each opening 36a, and the grease nipple 62 or the plug 61 is screwed together.

  The drive shaft portion D1 and the intermediate shaft portion D3, and the driven shaft portion D2 and the intermediate shaft portion D3 are connected via the universal joint 1 configured as described above. Specifically, of the four bearing cups 30, the key portions 38 of a pair of bearing cups 30 that face each other are fitted into a key groove 41 formed in the yoke 40, and the bearing fixing bolt 50 is inserted into the bolt insertion hole 39. At the same time, it is screwed into the screw hole of the yoke 40 and joined and fixed to the drive shaft portion D1 or the driven shaft portion D2.

  After the bearing cup 30 and the yoke 40 are joined and fixed, the plug 61 of one opening 36a of each bearing cup 30 is removed and the grease nipple 62 attached to the other opening 36a is opened. Grease is poured from. As the grease to be injected, for example, a lithium soap-based grease having water resistance is used.

  Grease is injected into the gap d through the through hole 36, air in the gap d is discharged from one opening 36 a, and the grease is filled into the gap d around the bearing fixing bolt 50 body 52. Then, with the gap d filled with grease, a plug 61 is attached to one opening 36a, and the opening 36a is sealed.

  According to the universal joint 1 of the said embodiment, the following effects can be acquired.

  When the universal joint 1 is used as a drive shaft of a rolling mill for steel, it is placed in a harsh and corrosive environment where the rolling water is constantly applied in addition to high temperature and high load. For this reason, when used continuously for a long period of time, rolling water enters from the joint surface of the bearing cup 30 and the yoke 40 (or the bearing cup 30 and the bolt seat surface), but the gap d between the bearing fixing bolt 50 and the bolt insertion hole 39 is Since the grease is filled, the rolling water cannot enter the gap d. Thereby, corrosion around the bearing fixing bolt 50 due to moisture remaining in the gap d can be prevented.

  Further, the guide portion 54 of the bearing fixing bolt 50 guides the barrel 52 so as to be positioned at the center of the bolt insertion hole 39 in a state where the bearing fixing bolt 50 is inserted into the bolt insertion hole 39. A gap d can be reliably formed between the portion 52 and the bolt insertion hole 39. As a result, the injected grease can be uniformly filled around the body portion 52, so that the rolling water can be prevented from entering the gap d over a long period of time.

  Further, since the joint area and the joint strength between the bearing cup 30 and the yoke 40 are not different from the conventional one, the torque transmission is not affected. Furthermore, the bearing fixing bolt 50 can be removed, and when it is removed, no foreign matter that obstructs the nondestructive inspection is attached, so that maintenance can be easily performed.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the invention described in the claims. For example, in the above embodiment, one bolt insertion hole is formed at each side position of the key part of the bearing cup, but a plurality of bolt insertion holes are formed at each side position of the key part, and a plurality of bearing fixing bolts are formed. Therefore, the present invention may be applied to a high-capacity universal joint that is bonded and fixed to the yoke.

  At this time, when an opening for injecting grease after assembly, such as a bolt insertion hole that is the innermost in the radial direction, cannot be provided on the outer peripheral surface of the bearing cup, a through hole that connects a plurality of bolt insertion holes is formed. As a result, the gaps between all the bolt insertion holes and the bearing fixing bolts communicate with each other, so that grease can be filled into all the communicating gaps by injecting grease from one opening.

  Moreover, in the said embodiment, although the universal joint is used for the drive shaft of the rolling mill for steel, you may use it for the drive shaft of a construction machine or a railway vehicle.

  1: Universal joint, 10: Cross shaft, 11: Shaft, 12: Body, 14: Track surface, 20: Needle roller (rolling element), 30: Bearing cup, 31: End surface on the inner periphery side, 32: Cylinder 33: inner periphery, 34: raceway surface, 35: outer peripheral side end, 36: through hole, 36a: opening, 37: outer peripheral surface, 38: key part, 39: bolt insertion hole, 40: yoke, 41: Keyway, 50: Bearing fixing bolt, 51: Head, 52: Body, 53: Screw part, 54: Guide part, 61: Plug, 62: Grease nipple, D: Drive shaft, D1: Drive shaft Part, D2: driven shaft part, D3: intermediate shaft part, S: gap, d: gap

Claims (2)

A cross shaft having raceway surfaces formed on the outer periphery of the four shaft portions;
A plurality of rolling elements that roll on the raceway surface of the shaft portion;
A bearing cup swingably attached to each of the shafts via the rolling elements;
With
The bearing cup is
A key portion protruding toward the yoke side on the joint surface with the yoke;
Bolt insertion holes formed on both sides of the key part;
Formed,
The key portion is fitted into a key groove formed in the yoke,
A bearing fixing bolt is inserted through the bolt insertion hole,
Screwed into the screw hole of the yoke,
In the universal joint joined and fixed to the yoke,
A plurality of through holes extending from the bolt insertion hole to the outer peripheral side end of the bearing cup are formed,
The through hole communicates with the opening on the outer peripheral surface of the bearing cup,
A universal structure characterized in that the opening is sealed in a state in which grease injected from the opening is filled in a gap between the bearing fixing bolt and the bolt insertion hole through the through hole. Joint. The universal joint according to claim 1,
The hole diameter of the bolt insertion hole is larger than the thread diameter of the bearing fixing bolt,
The bearing fixing bolt has a body diameter smaller than the thread diameter,
In the state where the bearing fixing bolt is inserted into the bolt insertion hole, an annular guide portion is provided at one end or both ends of the barrel portion to guide the barrel portion so as to be positioned at the center of the bolt insertion hole. Universal joint characterized by

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