JP2007247799A - Cross shaft joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cross shaft joint which can improve the durability of a bearing cup, and also can be simply repaired. <P>SOLUTION: The cross shaft joint has displacement sensors 7a. The cross shaft joint further comprises grease injection holes 8 provided in respective bearing cups 5, guide rings 11 fixed to the inside walls 8b of the holes 8, and lid bodies 12 which are fixed to the guide rings 11 by bolts, and close the other openings of the grease injection holes 8, and also hold the displacement sensors 7a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cross shaft joint incorporated in a drive shaft of a rolling facility or the like.

  For example, a drive shaft of a rolling mill for steel is connected between a rolling roller and a drive motor, and plays a role of transmitting the rotational force of the drive motor to the rolling roller. A cross shaft joint is provided in the middle of the drive shaft. In the rolling equipment, the steel material is rolled in a state where the movement of the rolling roller is allowed by the cross shaft joint. In this cross shaft joint, a bearing cup is provided on each of the four shaft portions of the cross shaft, and a roller is rotatably disposed between the cup and the shaft portion so that the outer peripheral surface of the shaft portion is a rolling surface. Therefore, during rolling of steel, a large load due to impact or the like is applied to the shaft portion and the bearing cup, and therefore damage due to long-term use is inevitable. Therefore, it is required to monitor the progress of damage and replace the cross shaft joint as soon as possible. For this purpose, it is necessary to detect the damage accurately and early on a shaft unit basis.

Therefore, as shown in FIG. 4, the applicant of the present invention first includes a cross shaft 103 having four shaft portions 102, a plurality of rolling elements 104, a bearing cup 105, and the shaft portion 102 and the bearing cup 105. It has a sensor unit 106a including a displacement sensor 107a and a slave unit 108a for detecting relative displacement for each shaft portion 102, an attachment portion 109a and a support portion 109b, and the displacement sensor 107a is accommodated therein. A cross shaft joint 101 including a lid 109, wherein the mounting portion 109 a is fixed to an inner wall of a grease injection hole 110 provided in each bearing cup 105, and the support portion 109 b is formed in the shaft portion 102. The displacement sensor 107a is disposed so as to be able to measure the displacement with respect to the inner wall of the hole 111. It was proposed cross joint 101 (see Patent Document 1). In the cross shaft joint 101, a lid 109 on which the displacement sensor 107 a is mounted is fixed to the bearing cup 105 by fastening a bolt to a threaded hole formed in the bearing cup 105 by female thread processing.
JP 2005-325981 A

However, since a carburizing material having a high surface hardness is usually used for the bearing cup 105, the fixing method described above may cause a crack from a threaded hole formed in the bearing cup 105. Further, when the threaded hole is damaged due to secular change, it is necessary to recreate the entire bearing cup 105, leading to an increase in repair costs.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cross joint that can improve the durability of the bearing cup and can be easily repaired.

The cross shaft joint of the present invention includes a cross shaft having a raceway surface formed on the outer periphery of four shaft portions,
A plurality of rolling elements that roll on the raceway surface of the shaft portion;
Bearing cups swingably attached to the shafts via the rolling elements;
A cruciform joint comprising a displacement sensor for detecting relative displacement between the shaft portion of the cross shaft and the bearing cup for each shaft portion,
A hole for grease injection formed in each bearing cup and penetrating along the axial direction of the cross shaft in a state where one opening faces the end surface of the shaft portion of the cross shaft;
A guide ring fixed to the inner wall of the grease injection hole;
And a lid that is bolted to the guide ring, closes the other opening of the grease injection hole, and holds the displacement sensor.

  According to this configuration, since the lid body on which the displacement sensor is mounted is bolted to the guide ring fixed to the inner wall of the grease injection hole, it is not necessary to process the female thread on the bearing cup. For this reason, it is possible to prevent cracks from occurring in the bearing cup. Even if the threaded hole is damaged, it is not necessary to recreate the entire bearing cup, and it is sufficient to replace only the guide ring. This leads to a reduction in repair costs for the cross joint.

In the cross joint, the inner wall of the grease injection hole may be provided with a protrusion that restricts the guide ring from being pulled out of the hole. In this case, providing the protrusion on the guide ring makes it difficult for the guide ring to come out of the hole.
In the cross joint, the guide ring may be tightly fitted to the inner wall of the grease injection hole. Also in this case, the guide ring is difficult to be removed from the hole.

  According to the cross joint of the present invention, the durability of the bearing cup can be improved and repair can be easily performed.

Hereinafter, a preferred embodiment of a shaft coupling monitoring device of the present invention will be described with reference to the drawings. In addition, in the following description, the case where it applies to the cross shaft coupling built in the drive shaft of rolling equipment is illustrated and demonstrated.
FIG. 1 is a perspective view showing a drive shaft D used in a steel manufacturer's rolling equipment, and FIG. 2 is a view of the main part of the cross joint 1 according to an embodiment of the present invention as seen from the axial direction of the drive shaft D. It is a partial missing figure. In the drawing, a cross shaft joint 1 is used in the vicinity of both ends of the drive shaft D, and a drive motor (not shown) is provided on one end side and the other end side of the drive shaft D with the joint 1 interposed therebetween. Steel rolling rollers are connected to each other. In other words, in addition to the intermediate shaft portion (first shaft portion) D1 disposed between the two cross joints 1, the drive shaft D is connected to the motor and the roller side (second shaft). A shaft portion) D2 and a driven shaft portion (third shaft portion) D3 are provided. The intermediate shaft portion D1 and the drive shaft portion D2 are connected by one cross shaft joint 1, and the other cross shaft joint 1 is connected. The intermediate shaft portion D1 and the driven shaft portion D3 are connected (see FIG. 1). Further, in the rolling equipment, two drive shafts D are arranged in parallel to each other, and a rolled steel material is manufactured by passing a slab or the like between the two rollers connected to each drive shaft D. Is configured to do. Further, during this rolling process, each cross joint 1 transmits the rotational force of the drive motor to the rolling roller in a state where the connected drive shaft D is allowed to tilt from the axial direction. Furthermore, by providing each cross shaft joint 1, when each rolling roller is worn or when the rolling width of the steel material is changed, the distance between the upper and lower roller cores can be easily adjusted.

  The cross shaft joint 1 includes a cross shaft 3 having raceway surfaces formed on the outer periphery of four shaft portions 2, a plurality of rolling elements (here, rollers) 4 that roll on the raceway surface of the shaft portion 2, A relative displacement between the bearing cup 5 swingably attached to each shaft portion 2 via the rolling element 4 and the shaft portion 2 of the cross shaft 1 and the bearing cup 5 is detected for each shaft portion 2. And a sensor unit 6a including a displacement sensor 7a. Here, an inner ring raceway surface 2 a is formed on the outer periphery of the shaft portion 2, and an outer ring raceway surface 5 a is formed on the inner periphery of the bearing cup 5. In addition, the pair of upper and lower bearing cups 5 in FIG. 2 are arranged on the shaft portion (for example, the drive shaft portion D2) of the drive shaft D on one side in the axial direction when viewed from the cross joint 1, and the pair of left and right bearing cups 5 are shafts. It is connected to a shaft portion (for example, the intermediate shaft portion D1) of the drive shaft D on the other side in the direction. Specifically, a flange portion formed at an end portion of a corresponding shaft portion of the drive shaft D through a bolt screwed into a bolt hole 5b provided on the left and right end portions of the bearing cup 5 includes the bearing cup 5. In the state where the center part of the left and right sides of the cross shaft 1 is almost in close contact with the end of the shaft part, and the cross shaft 1 is incorporated in the drive shaft D with almost no exposure to the outside. The shaft is connected.

  The bearing cup 5 is provided with a hole 8 for injecting grease. The grease injection hole 8 is formed so as to penetrate along the axial direction of the cross shaft 1 with one opening 8 a facing the end surface 2 b of the shaft portion 2 of the cross shaft 1. Further, a thrust washer 9 made of, for example, a synthetic resin is disposed on the bottom surface 5c of the bearing cup 5 between the end surface 2b of the shaft portion 2, and the bottom surface 5c and the end surface 2b of the shaft portion 2 are made of metal. The end surface 2b of the shaft portion 2 is supported in a state where contact is prevented. Further, a thrust washer 16 made of, for example, a synthetic resin is disposed on the bottom surface 5c of the bearing cup 5 between the shaft end portion of the shaft 12a, and the bottom surface 131f and the shaft end portion are in metal contact. The shaft end is supported in a protected state. Further, each shaft portion 2 of the cross shaft 3 is formed with a hole 10 concentrically around the central axis of the shaft portion 2 coaxially with the grease injection hole 8. The grease injection hole 8 and the hole 10 formed in the shaft portion 2 are connected to each other inside the cross shaft joint 1. The hole 10 constitutes a grease passage through which grease that lubricates a rolling contact portion between the shaft portion outer peripheral surface 2a and the bearing cup inner peripheral surface 5a of the rolling element 4 flows.

A guide ring 11 is fixed to the inner wall 8b of the hole 8 for grease injection. The inner wall 8b of the grease injection hole 8 is provided with a protrusion 8c for restricting the guide ring 11 from being removed from the hole 8. Further, a threaded hole 11a is formed in the front and back direction of the guide ring 11, and the guide ring 11 is tightly fitted to the inner wall 8b of the grease injection hole 8 by cold fitting or press fitting. By providing the protrusion 8c on the inner wall 8b and fixing the guide ring 11 with an interference fit, the guide ring 11 is more difficult to come off.
Further, the other opening 8d of the grease injecting hole 8 is detachably closed by the lid body 12 to prevent the grease from leaking to the outside from the rolling contact portion. More specifically, the lid body 12 has a mounting portion 12a with a flat bottom collar, and a round bar-shaped support portion 12b extending from the bottom portion in the axial direction of the shaft portion 2. A bolt hole 13a is formed in the mounting portion 12a. By screwing the bolt 13 into the threaded hole 11a of the guide ring 11 via the bolt hole 13a, the lid 12 is interposed via the guide ring 11. Attached to the bearing cup 5.

Further, as shown in FIG. 3, the lid 12 is fixed to the guide ring 11 with the displacement sensor 7a accommodated in the support portion 12b, and the support portion 12b has a gap 10a in the hole 10 of the shaft portion 2. Thus, the displacement sensor 7a is arranged so as to be able to measure the displacement L with respect to the inner wall 10b of the hole 10 of the shaft portion 2. Thereby, it is possible to detect damage such as separation and cracks on the inner ring raceway surface 2a between the rolling elements 4 formed on the outer periphery of the corresponding shaft portion 2. Here, for example, an eddy current type magnetic type sensor is used as the displacement sensor 7a. The displacement sensor 7a applies a high-frequency magnetic field to the surface layer portion of the inner wall 10b through the opening, and is generated in the surface layer portion. A change in the radial direction (relative displacement) of the shaft portion 2 that changes according to the cup swing is detected by obtaining an impedance change caused by the eddy current using the built-in coil.
The sensor unit 6a including the displacement sensor 7a includes the displacement sensor 7a and a slave unit 14a that wirelessly transmits a detection result of the displacement sensor 7a to a master unit (not shown) described later. , 14 a are connected via a cable 15. Here, the subunit | mobile_unit 14a is attached to the said attachment part 12a so that attachment or detachment is possible.
Similarly, the other three shaft portions 2 are also provided with slave units 14b, 14c, and 14d connected to the lid 12 (not shown) and the displacement sensors 7b, 7c, and 7d, respectively. The sensor results corresponding to the parent device are transmitted from each of the child devices 14b to 14d.

  For example, a panel computer disposed in the rolling equipment is connected to the parent machine via a communication line compliant with RS232C. The panel computer is connected to a personal computer installed in a monitoring room away from the rolling equipment via a LAN using, for example, a 10Base-T line. This personal computer is connected to a communication network such as the Internet. For example, it is configured to be connectable to an information processing terminal such as a manufacturer of the cross joint 1 or its maintenance company. Note that the slave units 14a to 14d are mounted on the four cross joints 1 assembled to the two drive shafts D, and the panel computer and the personal computer transmit the transmission data from all the slave units to the ID number. The cross joint 1 can be monitored in units of the two shaft portions. Here, the ID number is a continuous integer 0, 1, 2, 3 assigned as an identifier to each of the slave units 14a to 14d. In each of the slave units 14a to 14d, the sensor detection result For example, when transmitting, the transmission wave is transmitted including the ID number assigned to the header portion. And each subunit | mobile_unit 14a-14d and the displacement sensors 7a-7d connected to these subunit | mobile_units 14a-14d can be specified.

  In the present embodiment configured as described above, the lid body 12 equipped with the displacement sensor 7a is bolted to the bearing cup 5 via the guide ring 11 fixed to the inner wall 8b of the grease injection hole 8. Yes. Accordingly, since it is not necessary to form a threaded hole in the bearing cup 5, it is possible to prevent the bearing cup 5 from being cracked. Further, even if the threaded hole is damaged, it is not necessary to recreate the entire bearing cup 5 and only the guide ring 11 needs to be replaced. This leads to a reduction in the repair cost of the cross joint 1.

In the above description, the cross shaft joint 1 incorporated in the drive shaft D of the rolling equipment has been described. However, the present invention detects the relative displacement between the shaft portion 2 of the cross shaft 3 and the bearing cup 5. What is necessary is just to provide the displacement sensor 7a in the said bearing cup 5 side, for example, it can also be set as the cross shaft coupling 1 of the drive shaft D assembled | attached to a rail vehicle.
In the above description, the displacement sensor 7a can be attached to and detached from each bearing cup 5 so as to measure the distance from the inner wall 8b of the grease passage hole 8 (ie, the radial displacement of the shaft portion 2). Although the structure fixed to the lid 12 was described, the installation location and the detection location of the displacement sensor 7a of the present invention are not limited to this, and are caused by damage caused on the rolling surface 2a of the shaft portion 2. There is no limitation as long as the relative displacement between the shaft portion 2 and the bearing cup 5 generated when the shaft portion 2 is bent can be detected. Specifically, the distance between the thrust washer 9 tilted toward the bottom surface 5c of the bearing cup 5 when the shaft portion 2 is bent, that is, the axial displacement of the shaft portion 2 is measured by the displacement sensor 7a. Thus, a configuration for detecting the relative displacement may be used.

  Further, in the above description, the configuration using the eddy current type displacement sensor 7a has been described. It is not limited to anything. Specifically, another type of displacement sensor 7a such as a capacitance type, an optical type, an ultrasonic type, or a contact type may be used. However, when the eddy current type sensor is used, the configuration of the sensor itself is more compact than the other types, so that it can be easily attached. The eddy current sensor is also preferable in that it can be provided on the bearing cup 5 side without blocking the opening of the installation hole because the displacement can be detected normally even in a state of being impregnated with grease.

It is a perspective view which shows the drive shaft used for the rolling equipment of a steel maker. FIG. 5 is a partial cutaway view of the main part of the cross joint according to the embodiment of the present invention as viewed from the axial direction of the drive shaft. It is an expanded sectional view which shows the displacement sensor of the shaft coupling monitoring apparatus attached to the said cross shaft coupling. FIG. 10 is a partially cutaway view of a conventional cross shaft joint viewed from the axial direction of a drive shaft.

Explanation of symbols

D drive shaft 1 cross shaft joint 2 shaft portion 3 cross shaft 4 rolling element 5 bearing cup 6a to 6d sensor unit 7a to 7d displacement sensor 8 hole for grease passage 11 guide ring 12 lid

Claims (3)

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;
Bearing cups swingably attached to the shafts via the rolling elements;
A cruciform joint comprising a displacement sensor for detecting relative displacement between the shaft portion of the cross shaft and the bearing cup for each shaft portion,
A hole for grease injection formed in each bearing cup and penetrating along the axial direction of the cross shaft in a state where one opening faces the end surface of the shaft portion of the cross shaft;
A guide ring fixed to the inner wall of the grease injection hole;
A cross shaft joint comprising: a lid that is bolted to the guide ring, closes the other opening of the grease injection hole, and holds the displacement sensor.   2. The cross shaft joint according to claim 1, wherein a protrusion for restricting the guide ring from being pulled out from the hole is provided on an inner wall of the grease injection hole.   The cross shaft joint according to claim 1, wherein the guide ring is tightly fitted to an inner wall of the grease injection hole.

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