JP2005098382A - Universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely prevent deflecting move between divided base plates when the base plates are joined with each other in a universal joint for transmitting large torque. <P>SOLUTION: At axial ends of a drive shaft 1, a pair of arms 2 and 2 are provided to be axially extended in parallel. Between tips of the arms 2 and 2, one shaft 3a of cross shafts 3 is journaled, and the other shaft 3b of the cross shafts is journaled between tips of another pair of arms 4 and 4 that are parallel. The arms 4 and 4 are integrally coupled with axial ends of a driven shaft 5. Base plate parts 7 on which the arms 2 and the arms 4 are provided are formed to be respectively divided between the arms 2 and 4. The base plate parts 7 and 7 divided from each other can be coupled with each other through a yoke part 9. In this universal joint for transmission of high-torque and low-speed rotation, the base plate parts disposed on the drive shaft side and the driven shaft side for respectively supporting arms 2 and 4 are provided with a fastening means 10 to fit divided surfaces 7a to each other to couple them to be integrated with each other, and key members 16 and 17 forcedly fitted in between the divided surfaces. Relative move between the divided surfaces 7a is thus prevented by their cooperation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a universal joint, and more particularly, to an improvement in a universal joint capable of high torque conduction in addition to a normal use state.

Conventionally, a universal joint as shown in FIG. 10 is known as a universal joint such as a drive shaft of a rolling mill or a drive shaft of a press machine (Patent Document 1).
This universal joint is usually provided with a pair of arms 2 and 2 extending in parallel in the axial direction at the shaft end of the drive shaft 1, and one shaft 3 a of the cross shaft 3 is connected between the ends of the arms 2 and 2. The other shaft 3b of the cross shaft 3 is pivotally supported between the tips of the other pair of arms 4 and 4, and the other arms 4 and 4 are integrally coupled to the shaft end 6 of the driven shaft 5. is there.

  By the way, in the case of a universal joint that conducts rotation with high torque, the arms 2 and 4 that support the cross shaft 3 have sufficient strength to withstand high torque conduction, so that the drive shaft 1 side and the driven shaft 5 side are provided. The pair of arms 2, 2, 4, and 4 are integrally formed with the base portions 7 and 7, and the arms 2, 2, 4, and 4 are assembled to the base portions 7 and 7 with bolts or the like. (Not shown).

  In other words, the arm is integrally molded on the base, which is far stronger than the assembly structure using bolts, and if the mounting bolt is inserted in the axial direction of the arm, the diameter of the cross shaft bearing must be reduced accordingly. Since the shaft diameter of the cross shaft 3 cannot be increased, the arm is formed integrally with the base portion.

  Therefore, in order to make it possible to attach the cross shaft 3 to the bearings 8 of the arms 2, 2, 4, 4, the base portions 7, 7 can be divided between the arms 2, 2, 4, 4, respectively. Each base part 7, 7 is brought into contact with the divided surfaces 7 a, 7 a and fastened with a radial bolt 10, and then integrally coupled to the drive shaft end or the driven shaft end via the yoke parts 9, 9. (Patent Document 1). The yoke portion 9 shown here is a semicircular projection 9c, 9c projecting on the back surface of the base portion 7, 7, and a projection 12 that becomes cylindrical by combining the two projections 9c, The semicircular protrusion 9c, the protrusions 9b and 9b provided in the radial direction across the circumferential groove 9d, and the groove 9a fitted with these protrusions without a gap.

  By the way, although the base portion 7 is coupled to the shaft by the yoke portion 9, if there is even a slight gap in the fitting portion between the yoke groove 9a and the projection 9b of the yoke portion 9, a strong torque is generated between the rotating shafts. As shown in FIG. 11, a force to displace left and right as shown by arrows T and T is applied to the divided base portion 7 as shown in FIG. As shown, the split surface 7a is torsionally displaced, and the axial bolt 11 for fixing the base portion 7 to the yoke portion 9 (see FIG. 10) must directly counter this force. There is a possibility that the durability of the bolt 11 may be adversely affected.

Further, in order to suppress such displacement, a ring 13 is provided on the outer periphery of the protrusion 12 formed on the outer surface of the base parts 7, 7, for example, as shown in FIG. It has been practiced to make an interference fit by shrink fitting or to provide a face gear 14 that meshes with the divided surfaces 7a and 7a as shown in FIG. 13 (Patent Document 1).
JP-A-7-113425

  However, the means for fitting the ring 13 into an interference fit state cannot prevent the sliding movement between the smooth divided surfaces 7a and 7a of the base portions 7 and 7, no matter how strong the tightening force can be. The shift movement between the divided base portions 7 and 7 cannot be completely prevented. Also, with the face gear 14, it is very difficult to form the gear into an accurate tooth shape without a gap, and if there is even a gap between the teeth that mesh with each other, the degree of the gap Accordingly, the occurrence of torsional deformation cannot be prevented, and eventually there is a problem that it is impossible to prevent excessive repeated stress from being generated in the axial bolts 11 that fix the base portions 7 and 7 to the drive shaft or driven shaft end face. It was.

  An object of the present invention is to solve the above-mentioned problems and to surely prevent displacement movement between divided bases of a universal joint for transmitting a strong torque.

  In order to solve the above problems, the present invention is provided with a pair of arms extending in the axial direction at the shaft end of the drive shaft, and one of the cross shafts is pivotally supported between the tips of the arms, A universal joint in which the other shaft of the cross shaft is pivotally supported at the tip of another pair of parallel arms, and the other pair of arms is integrally coupled to the shaft end of the driven shaft. The base portions on which the pair of arms are erected can be divided between the arms, respectively, and the divided base portions are integrated with the drive shaft end and the driven shaft shaft end through yoke portions. In the universal joint that can be coupled, the fastening means disposed on the drive shaft side and the driven shaft side, each supporting the arm, presses the divided surfaces of each other, and integrally couples, A key member forcibly press-fitted between the divided surfaces, It is characterized in that to prevent relative movement in the dividing plane of the two base portions by cooperation with the key member and the.

  In other words, the key member is press-fitted into the split surface of the base portion integrated by the fastening means, thereby reliably preventing the shift of the split surface due to the rotational torque transmission of the split portion. There are two types of directions in which the gradient key is press-fitted in the radial direction and the axial direction with respect to the divided base portion.

1 is an exploded perspective view of a universal joint according to an embodiment of the present invention, FIG. 2 is a perspective view of a main part, and FIG. 3 is an enlarged cross-sectional view of a state A in FIG.
In FIG. 1, the universal joint is provided with a pair of arms 2, 2 extending in the axial direction on the surface of the base portion 7 joined by a yoke portion 9 formed at the shaft end of the drive shaft 1, as in the prior art. One shaft 3a of the cross shaft 3 is pivotally supported between the tips of the arms 2 and 2, and the other shaft 3b of the cross shaft 3 is pivotally supported between the tips of the other pair of arms 4 and 4. A pair of arms 4, 4 are provided on the surface of the base parts 7, 7, and after the base parts 7, 7 are integrated with the radial bolt 10, the shaft end 6 of the driven shaft 5 is connected via the yoke part 9. Configured to be combined.

  The protrusions 9b and 9c constituting the yoke portion 9 and the fitting groove 9a and the like are the same as those described in FIG. 10, and the semicircular protrusions 9c protruding from the back surfaces of the base portions 7 and 7 are combined. Thus, the cylindrical projection 12 and the projections 9b, 9b provided in the radial direction are fitted into the fitting groove 9a on the rotating shaft side, and the axial bolts 11 are fastened and fixed. Yes.

  Key grooves 15 and 15 are formed in symmetrical positions on the dividing surface 7a of the base portions 7 and 7 divided into two from the outer periphery toward the center in the radial direction. 16 and 17 can be press-fitted.

  The gradient keys 16 and 17 are composed of two key members 16 and 17 having inclined surfaces 18 having the same inclination angle in opposite directions as shown in an enlarged view in FIG. The key member 16 that increases in thickness as it goes is inserted into the key hole 15h, and then another key member 17 is slid along the inclined surface 18 of the key member 16 to press fit the inner surfaces of both the key holes 15h. The contact pressure is increased so that the two base portions 7 and 7 cannot be moved relative to each other.

In FIG. 3, 20 is a positioning pin for the gradient key 16, 21 is a set screw for the gradient keys 16 and 17, and 22 is a tap for removing the gradient key 17.
In FIG. 1, 30 is an inner ring of a bearing, 31 is a bearing cover, 32 is an O-ring, 33 is a dust seal, 34 is a bearing roller, 35 is an outer ring of the bearing, and 36 is a thrust washer. It is a structural member of the bearing bearing of the cross shaft 3, and is provided at each shaft end.

  According to this universal joint, the gradient keys 16 and 17 are driven into the key holes 15h formed by the key grooves 15 formed in the split surfaces 7a and 7a, so that the radial bolts 10 of the split surfaces 7a are centered relative to each other. The movement can be prevented, and the relative rotational displacement of the divided surfaces 7a and 7a when high torque conduction is performed is prevented. Accordingly, it is possible to prevent an excessive force from being applied to the axial bolts 11 (FIG. 1) for fixing the respective base portions 7 to the drive shaft 1 or the yoke portion 9 of the driven shaft 5, and fatigue failure of the axial bolts 11. Such dangers are avoided.

Therefore, the universal joint of the present invention can be used not only as an ordinary universal joint, but also as a universal joint for high torque conduction that transmits rotational conduction to a rolling mill or the like.
In addition, when performing high torque rotation conduction like rotation conduction to a rolling mill, since the surface pressure in the key groove 15 provided in the base | substrate part 7 may become high, in this case on the inner surface of the key groove 15 Surface treatment such as metal spraying or quenching may be performed to increase the surface strength.

Although the case where the key groove 15 is provided in the radial direction with respect to the base portion 7 has been described as the above embodiment, it can also be provided in the axial direction.
FIG. 4 shows a cross-sectional view of the main part when the key groove is provided in the axial direction of the dividing surface 7a.

  In FIG. 4, rectangular key grooves 19 are provided on the dividing surface 7a at positions where they are symmetrical to each other along the axial direction, and in the key holes 19a formed by the pressure-contacted dividing surfaces 7a and 7a, the key grooves 19a face in the axial direction. The gradient keys 16 and 17 are configured to be driven. On the other hand, the divided base portions 7 and 7 can be integrally coupled by fastening a radial bolt 10.

In this case, the divided base portions 7 and 7 are integrally coupled with the radial bolts 10 and then the gradient keys 16 and 17 are driven to reliably prevent the relative movement of both divided surfaces.
Therefore, in this case, too much force can be prevented from being applied to the axial bolts 11 for fixing the respective base portions 7 to the shaft ends of the drive shaft 1 or the driven shaft 5, and fatigue breakage of the axial bolts 11. The danger of is avoided. Although not shown in the figure, as a structure for preventing the keys 16 and 17 from being removed, a set screw and a punch tap as shown in FIG. 3 are provided.

In addition, a key and a key groove can be provided inside the base portion 7.
5 is a cross-sectional view when the key groove is provided inside the base portion 7, FIG. 6 is a cross-sectional view taken along line AA in FIG. 5, and FIG. 7 is a side view taken along the line BB in FIG.

  5-7, 24 shows the shaft hole drilled so that it may become coaxial with both the base parts 7 and 7, The cylindrical body 25 from which an internal diameter becomes taper-shaped is inserted in it. At the same time, a key 26 having a cross section whose outer diameter increases in a taper shape in the same manner as the taper angle is inserted therein, and a bolt 28 is inserted into a through hole 27 drilled from the side of the base portion 7 toward the shaft hole 24. Is inserted, the key 26 is screwed to the tip of the bolt 28, and the bolt 26 is tightened to move the key 26 while expanding the diameter of the cylindrical body 25.

  In the case of this universal joint, a cylindrical body 24 in which a key 26 is set is inserted into the shaft hole 24 in the base 7, and a bolt 28 is screwed into the key 26, and then the base parts 7 and 7 of the yoke part 9 are fitted. After fitting two projections 9c projecting on the back surface into a cylindrical shape 12 and the projections 9b and 9b into the yoke groove 9a, the bolts 28 are tightened to tighten the cylinder 25 into the shaft hole 24. In this way, the diameter is elastically expanded so that the inner surface of the shaft hole 24 is in close contact with the inner surface of the shaft hole 24 to prevent relative rotation of the base portions 7 and 7 divided by the fixing force.

In this embodiment, the cylindrical body 25 may be divided in the axial direction so that the diameter can be easily increased.
Further, the shaft hole 24, the cylindrical body 25 inserted into the shaft hole 24, and the key 26 are shown to have a circular cross section, but the present invention can be similarly implemented even if the cross section has a cross sectional shape such as an ellipse or other squares. .

Next, the direction in which the axial hole 24 is provided may be a direction along the axial direction as shown in FIG.
That is, FIG. 8 is a cutaway side view of the main part, and FIG. 9 is a plan view.
In FIG. 8, the base portion 7 of the universal joint is formed with semicircular cutout portions 29 and 29 along the axial direction on both sides across the dividing surface 7a as shown in FIG. When the divided surfaces 7a and 7a are combined, an axial hole 30 in the axial direction is formed. In the case of the example shown in FIG. 8, the shaft hole 30 is a tapered hole having a diameter that decreases in the direction of the yoke portion 9, and a tapered shape in which the shaft hole 30 is inclined in the opposite direction at the same angle as the taper angle of the shaft hole 30. A pin 31 having an outer surface is inserted, an attachment 32a is disposed on the yoke 9 side, and a bolt 32 inserted into the center hole 32b of the attachment can be screwed into the pin 31 and tightened. The base portions 7 and 7 are integrally fastened by respective bolts 34 and 34 inserted into bolt holes 33 and 33 formed in a direction perpendicular to the dividing surface 7 a at a position avoiding the shaft hole 30. Has been.

  Accordingly, the base portions 7 and 7 are integrally coupled by the bolt 34, and then the taper pin 31 is inserted into the shaft hole 30 and the bolt 32 is tightened so that the two base portions 7 and 7 can be fixed so as not to move relative to each other. Has been.

In addition, although the shaft hole 30 and the pin 31 inserted into the shaft hole 30 have a circular cross section, the present invention can be similarly implemented even if the cross section has a cross sectional shape such as an ellipse or other square.
Therefore, even if the arm assembled in this way is attached to the yoke portion 9 and fixed with the bolts 11..., It is impossible to use the bolts 11 for fixing the base portions 7 to the shaft ends of the drive shaft 1 or the driven shaft 5. Can be prevented, and danger such as fatigue failure of the fastening bolt 11 can be avoided.

  As described above, the universal joint according to the present invention conducts rotation conduction without causing excessive displacement in the arm portion of the universal joint, as well as normal rotation conduction, as well as high-torque rotation conduction. be able to.

It is a disassembled perspective view of the universal joint which is embodiment of this invention. It is a principal part perspective view of the universal joint which is embodiment of this invention. It is explanatory drawing at the time of the assembled state of the A section of FIG. 2, (a) is a horizontal expanded sectional view, (b) is a right view of (a) figure. It is principal part sectional drawing at the time of providing a keyway in the axial direction of the division surface 7a. FIG. 6 is a cross-sectional view when a keyway is provided in the base portion 7. It is the sectional view on the AA line of FIG. FIG. 6 is a sectional view taken along line B-B in FIG. 5. It is a principal part fracture | rupture side view of the other structural example. It is a top view of the example of a structure of FIG. It is a perspective view of a prior art example. It is a perspective view explaining the problem of a prior art example. It is a side view of a prior art example. It is a side view which shows an example of the conventional universal joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive shaft 2 A pair of arms 3 Cross shaft 3a One axis | shaft 3b The other axis | shaft 4 Another pair of arms 5 Driven shaft 6 Axis end 7 Base part 7a Dividing surface 9 Yoke part 10 Radial bolt 15 Key groove 15h Key hole 16 Gradient key 17 Gradient key 24 Shaft hole 25 Cylindrical body whose inner diameter decreases in a taper shape 26 Key with a circular cross section whose outer diameter increases in a taper shape 27 Through hole 28 Bolt

Claims (4)

A pair of arms extending in the axial direction is provided at the shaft end of the drive shaft, and one axis of the cross shaft is pivotally supported between the ends of the arms, and the other axis of the cross shaft is parallel to the other. A universal joint that is pivotally supported at the tip of a pair of arms, and the other pair of arms is integrally coupled to the shaft end of the driven shaft, and the base portion on which the pair of arms and the other pair of arms are erected is provided. In each of the universal joints, each of the divided base portions can be integrally coupled to the drive shaft end and the driven shaft end via a yoke portion. Fastening means that is arranged on the drive shaft side and the driven shaft side and that supports the respective arms, presses the divided surfaces together and integrally couples, and a key member forcibly press-fitted between the divided surfaces Both of the base portions by the joint of the fastening means and the key member Universal joint, characterized in that to prevent relative movement in the dividing plane. 2. The universal joint according to claim 1, wherein the fastening means for integrally joining the base portions supporting the respective arms is a yoke portion, and key grooves are formed at positions facing each other on the dividing surface of the base portion, and the fastening means. A universal joint characterized in that, when the base portions are joined together, a gradient key is press-fitted into a key hole formed by the key groove to prevent relative movement on the split surfaces of both base portions. The key groove formed in each split surface of the base portion of the universal joint according to claim 2 is a hollow hole having an axis perpendicular to the split surface, and the base portion is fixed to each other by a fastening member. A cavity is formed in the dividing surface by the hole, and a gradient key composed of a taper sleeve and a taper pin is inserted into the cavity, and a screw rod inserted from the outer surface of the base is screwed onto the taper pin. The taper pin is forcibly pulled toward the narrow diameter side of the taper sleeve by tightening and tightening, and the taper sleeve is expanded in diameter and pressed into the cavity to prevent relative movement on the split surfaces of both base portions. Universal joint characterized by The universal joint according to claim 3, wherein the axis of the keyway formed on the split surface of the base portion is along the axial direction of the base portion.

Images