JP2006017284A - Cardan joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Cardan joint not immediately producing wear or seizure of support guide member supporting or guiding a trunnion shaft and a roller in each axial direction such as a thrust washer, a roller washer and a roller guide by not running out of grease easily as compared to previous. <P>SOLUTION: A bottom surface 23 of a recess part 21 of a bearing case 2 and the thrust washer 4 arranged in a gap with a tip surface 13 of the trunnion shaft 11 of a cross shaft 1 of the Cardan joint is formed out of a porous body including a continuous pore structure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cross joint for connecting two shafts rotatably via a cross shaft.

For example, a drive shaft used for power transmission in a steel rolling mill, a railway vehicle, an automobile, or the like is incorporated with a cross shaft joint at both ends in order to connect the drive shaft to an input shaft and an output shaft. FIG. 3 is a partially cutaway front view showing an example of a conventional cross joint. FIG. 4 is an enlarged cross-sectional view of a part of the cross shaft joint.
Referring to FIG. 3, the cross shaft joint includes a cross shaft 91 having a shape in which four columnar trunnion shafts 911 are arranged in a cross shape, and a bottomed cylindrical recess 921 that receives each trunnion shaft 911. Each bearing case 92 so as to face the inner raceway surface 912 of the trunnion shaft 911 provided on the outer peripheral surface of the cylinder and at a predetermined interval. A structure in which a plurality of rollers 93 are arranged in a space between the outer raceway surface 922 provided on the cylindrical inner peripheral surface of the concave portion 921 of the 92 with its axis line parallel to the axis line of the trunnion shaft 911. Have. Each of the above parts is formed of a metal such as bearing steel.

  A thrust washer 94 is disposed between the tip surface 913 of each trunnion shaft 911 and the bottom surface 923 of the recess 921 of the bearing case 92 to support the trunnion shaft 911 in the axial direction therebetween. The roller 93 is interposed between the end surface 931 on the tip end surface 913 side of the trunnion shaft 911 and the bottom surface 923 of the recess 921 of the bearing case 92 to guide the roller 93 in the axial direction. A roller washer 95 is provided. Also, the roller guide for supporting the roller 93 in the axial direction by contacting the end surface 932 of the roller 93 opposite to the tip end surface side of the trunnion shaft 911 at the inlet 924 of the recess 921 of the bearing case 92. 96 is arranged. Further, between the roller guide 96 and the trunnion shaft 911, the space between the inner raceway surface 912 and the outer raceway surface 922 in which the rollers 93 are disposed is filled with grease to shield from the outside. An oil seal 97 is fitted.

The thrust washer 94 is made of a so-called engineering plastic such as polyacetal [Duracon (registered trademark) manufactured by Polyplastic Co., Ltd.] or the like, or a metal. Further, the roller washer 95 and the guide 96 are usually made of metal.
According to the cross shaft joint described above, in the figure, two bearing cases 92 fitted to two trunnion shafts 911 extending in the vertical direction across the center point of the cross shaft 91 are provided at the shaft end of one shaft. Two bearing cases 92 fixed to a yoke (not shown) and fitted to two trunnion shafts 911 extending in the left-right direction perpendicular to the above with the center point of the cross shaft 91 interposed therebetween are connected to the shaft end of the other shaft. By fixing to a yoke (not shown) provided on the two shafts, the two shafts can be rotatably connected, for example, with their axes intersecting.

  At the time of rotation of the cross joint, the cross shaft 91 and the bearing case 92 repeat left and right rotation at a constant angle about the center axes of the two substantially coincident with each other. At this time, the thrust washer 94 is sandwiched between the bottom surface 923 of the recess 921 of the bearing case 92 and the tip end surface 913 of the trunnion shaft 911 and receives the thrust load from the trunnion shaft 911 while It slides repeatedly between the bearing case 92. For this reason, when the grease runs out, the thrust washer 94 may be worn out, or the metal thrust washer 94 may be seized.

Therefore, in order to prevent wear and seizure of the thrust washer 94 due to the out of grease, it is generally performed to provide a groove for spreading the grease over one surface or both surfaces of the thrust washer 94 (for example, Patent Documents). 1). It is also known to improve the retention of lubricants such as grease by forming minute dimples (recesses) on one of the sliding surfaces between metals (see, for example, Patent Document 2). As an application, it is also conceivable to prevent wear and seizure of the thrust washer 94 due to grease exhaustion.
JP 2000-145806 A (Claim 1, columns 0002 to 0005, FIG. 2) JP-A-2003-13710 (Claim 1, columns 0006 to 0008, FIG. 1)

However, in the case of a cross joint used by being incorporated in a drive shaft for a steel rolling mill that rotates at a low speed under a high load, even if the above measures are taken, the effect is sufficient. Therefore, there is a problem that the thrust washer 94 is likely to be worn and seized due to the lack of grease.
As the cause of this, if rotation with a high load is repeated, the inner raceway surface 912 of the trunnion shaft 911, the roller 93, and the outer raceway surface 922 of the bearing case 92 are worn, and the trunnion shaft 911 93 and the recess 921 It is conceivable that the gap between them becomes large and the center axis of the trunnion shaft 911 and the center axis of the recess 921 of the bearing case 92 are shifted when the cross joint is rotated.

That is, referring to FIG. 4, when the clearance between the trunnion shaft 911 93 and the recess 921 becomes large, the center axis C ₁ of the trunnion shaft 911 and the recess 921 of the bearing case 92 are rotated during the rotation of the cross joint. and the central axis C ₂ is caused a slight shift in the rotational direction about the center point of the cross shaft 91, accompanying this displacement, the thrust load from the trunnion shaft 911 is added to the thrust washer 94, the rotation of the cross joint The direction is uneven on the front side and the rear side.

More specifically, when the cross shaft 91 is on the input shaft side and the bearing case 92 is on the output shaft side, and the cross shaft joint rotates in the clockwise direction in the figure, the cross shaft 91 moves relative to the bearing case 92. since that will rotate ahead by the amount of displacement of both the central axis axis C _1, C _2, the thrust load from the trunnion shaft 911 is added to the thrust washer 94 is smaller in the direction of rotation front side (left side in the drawing) , Increase on the rear side (right side in the figure). Conversely, when the cross shaft 91 is on the output shaft side and the bearing case 92 is on the input shaft side, and the cross shaft joint rotates in the counterclockwise direction in the figure, the bearing case 92 moves relative to the cross shaft 91. since that will rotate ahead by the amount of displacement of both the central axis axis C _1, C _2, the thrust load from the trunnion shaft 911 is added to the thrust washer 94 is larger in the direction of rotation front side (left side in the drawing) , Smaller on the rear side (right side in the figure).

Then, on the side where the thrust load is increased, the grease is pushed out from the sliding surface between the front end surface 913 of the trunnion shaft 911 and the thrust washer 94 to cause the grease to run out and wear and seizure occur.
Also, referring to FIG. 3, when the cross joint is rotated, the cross shaft 91 rotates while being shifted downward in the vertical direction by the amount of the gap. The weight of the cross joint and the shaft connected thereto is added to the thrust load applied to the thrust washer 94 in the case 92, and the grease is pushed out from the sliding surface between the front end surface 913 of the trunnion shaft 911 and the thrust washer 94. This causes the grease to run out and cause wear and seizure.

  The problem of wear and seizure due to grease shortage is not limited to the thrust washer 94, and both end surfaces 931 of the roller 93 repeatedly move left and right for a certain number of rotations between the inner and outer raceway surfaces 912 and 922 when the cross joint is rotated. , 932 is also generated in the roller washer 95 and the roller guide 96. In addition, as described above, the problem of wear and seizure due to grease shortage is prominent in a cross shaft joint that rotates at a low speed under a high load condition, such as by incorporating it into a drive shaft for a steel rolling mill. However, it is also a problem in a cross shaft joint that is incorporated in a drive shaft of a railway vehicle, an automobile, or the like and is rotated at a higher speed with a lower load.

  Since the object of the present invention is less likely to cause grease breakage than before, members (support guide members) for supporting or guiding the trunnion shafts such as thrust washers, roller washers, and roller guides in the respective axial directions are immediately provided. An object of the present invention is to provide a cross joint that does not wear or seize.

  The present invention includes a cross shaft having a shape in which four columnar trunnion shafts are arranged in a cross shape, and four bearing cases having a bottomed cylindrical recess that individually receives each trunnion shaft, and The inner raceway surface provided on the outer peripheral surface of the cylinder of each trunnion shaft, and the outer raceway provided on the cylindrical inner peripheral surface of the recess of each bearing case so as to face the inner raceway surface with a certain distance. A cross-joint joint in which a plurality of rollers are arranged with the axis thereof parallel to the trunnion shaft, and the support guide member that supports or guides the trunnion shaft in each axial direction. The support guide member is made of a porous body having a continuous pore structure.

The support guide member is preferably made of a sintered body of polyimide resin powder.
Examples of the support guide member include a thrust washer disposed between the front end surface of the trunnion shaft and the bottom surface of the concave portion of the bearing case, and the thrust washer is formed of a porous body having a continuous pore structure. Is preferred.

  According to the present invention, the support guide member is formed of a porous body having a continuous pore structure, so that the continuous pore structure of the support guide member can be impregnated with a significantly larger amount of grease than the conventional dimples. it can. When excessive thrust pressure is applied to the support guide member during rotation of the cross joint, it is possible to prevent the grease from leaching out of the continuous pore structure due to the pressure, which is good. Smooth sliding can be maintained.

  Further, when a sintered body of polyimide resin powder is used as the support guide member, since the polyimide resin is excellent in heat resistance, mechanical strength, etc., it is difficult to cause wear and the like, and the sintered body of polyimide resin powder However, it is superior in flexibility compared to, for example, a metal porous body, and can smoothly leach out a large amount of grease when pressure is applied. The effect of maintaining smooth sliding can be made even more effective.

The configuration of the present invention is as follows.
-As explained above, the thrust washer is directly subjected to the thrust pressure from the trunnion shaft, so it is the member that is most prone to grease breakage among the support guide members,
The thrust washer has the largest volume among the support guide members, and therefore, it can be impregnated with the largest amount of grease by making the thrust washer porous.
・ Therefore, the grease leached from the thrust washer can be distributed to other supporting and guiding members such as roller washers and roller guides to prevent these members from running out of grease.
In consideration of the above, it is preferable to apply to a thrust washer.

FIG. 1 is a partially cutaway front view of a cross joint according to an embodiment of the present invention. FIG. 2 is an exploded perspective view, partly cut away, of the cross joint.
Referring to FIGS. 1 and 2, the cross joint of this example includes a cross shaft 1 having a shape in which four columnar trunnion shafts 11 are arranged in a cross shape, and a bottomed structure that receives each trunnion shaft 11. The four bearing cases 2 having cylindrical recesses 21 are provided, and the inner raceway surface 12 provided on the outer peripheral surface of the column of each trunnion shaft 11 is opposed to the inner raceway surface 12 with a certain interval. Thus, in the space between the outer raceway surface 22 provided on the cylindrical inner peripheral surface of the recess 21 of each bearing case 2, the plurality of rollers 3 are arranged with the axis thereof parallel to the axis of the trunnion shaft 11. It has an arranged structure. Each of the above parts is formed of a metal such as bearing steel, as in the prior art.

  A thrust washer 4 is disposed between the front end surface 13 of each trunnion shaft 11 and the bottom surface 23 of the recess 21 of the bearing case 2 so as to support the trunnion shaft 11 in its axial direction. The roller 3 is interposed between the end surface 31 on the front end surface 13 side of the trunnion shaft 11 and the bottom surface 23 of the recess 21 of the bearing case 2 to guide the roller 3 in the axial direction. A roller washer 5 is provided. Further, the roller guide for supporting the roller 3 in the axial direction by contacting the end surface 32 of the roller 3 on the opposite side to the front end surface side of the trunnion shaft 11 at the inlet 24 of the recess 21 of the bearing case 2. 6 is disposed. Further, between the roller guide 6 and the trunnion shaft 11, the space between the inner raceway surface 12 and the outer raceway surface 22 where the rollers 3 are disposed is filled with grease, and is shielded from the outside. The oil seal 7 is fitted.

  Referring to FIG. 2, the cross joint is a pair of bearing cases 2 fitted to two trunnion shafts 11 extending in the vertical direction across the center point of the cross shaft 1 in the figure. Two bearing cases fixed to a yoke Y provided at the shaft end of the front shaft of the shaft and fitted to two trunnion shafts 11 extending in the left-right direction perpendicular to the above with the center point of the cross shaft 1 interposed therebetween By fixing 2 to a yoke Y provided at the shaft end of the far side shaft, the two shafts are used to be rotatably connected, for example, in a state where the axes intersect.

  The bearing case 2 and the yoke Y protrude from the end face Y1 of the yoke Y facing the cross shaft joint on the side of the bearing case 2 on the side of the yoke Y to be fixed. It fits into the recess Y3 between the provided yoke claws Y2 and restricts the movement of the shaft in the rotational direction, and penetrates the bearing case 2 provided on both sides of the protrusion 25 of each bearing case 2 in the axial direction. The screws B are inserted into the pair of through holes 26 and fixed by screwing into the screw holes Y4 provided in the end face Y1 of the yoke Y.

Referring to FIGS. 1 and 2, in the cross shaft joint of this example, a thrust washer 4 as a support guide member for supporting or guiding the trunnion shaft 11 and 3 in the respective axial directions among the above portions, Of the roller washer 5 and the roller guide 6, the thrust washer 4 is formed of a porous body having a continuous pore structure as described above.
In the present invention, any of the thrust washer 4, the roller washer 5, and the roller guide 6 as the support guide member may be formed of a porous body having a continuous pore structure, and among these three members Two or three of these may be formed by a porous body having a continuous pore structure. But as I explained earlier,
-Since the thrust washer 4 directly receives the thrust pressure from the trunnion shaft 11, it is the member that is most likely to run out of grease among the support guide members.
The thrust washer 4 has the largest volume among the support guide members. Therefore, the thrust washer 4 can be impregnated with the largest amount of grease by making the thrust washer 4 porous.
-Therefore, the grease leached from the thrust washer 4 can be distributed to other supporting guide members such as the roller washer 5 and the roller guide 6 to prevent the grease from running out of these members.
In consideration of the above, it is most preferable that the thrust washer 4 is formed of a porous body having a continuous pore structure. Further, when the thrust washer 4 is formed of a porous body having a continuous pore structure as described above, other supporting guide members such as the roller washer 5 and the roller guide 6 are made of a non-porous metal as in the prior art. Preferably formed.

  As a porous body having a continuous pore structure that forms the thrust washer 4 and the like, for example, a large number of metal particles are sintered under the condition that they are not melted and completely integrated, and voids between the metal particles are formed in the interior. It is also possible to use a metal sintered body with a continuous pore structure based on the above, but it is more flexible than a metal sintered body in consideration of leaching a large amount of grease smoothly when subjected to thrust pressure. A porous body of resin is preferable, and as the porous body of resin, a sintered body of a polyimide resin excellent in heat resistance, mechanical strength and the like, particularly a wholly aromatic polyimide resin powder is preferable.

  Such a sintered body is formed, for example, by filling the mold with a powder of wholly aromatic polyimide resin, hot press molding in which the powder is heated, compressed, and sintered, or by filling the mold with the powder and pressing it at room temperature. The preform can be formed by sintering or the like that is sintered in an inert gas atmosphere. And the continuous pore structure based on the space | gap between powder can be formed inside a sintered compact by adjusting the pressure, sintering temperature, etc. which are added to powder in these shaping | molding methods.

It is a partially notched front view of the cross shaft coupling concerning one Embodiment of this invention. It is a partially cutaway exploded perspective view of the cross joint. It is a partially cutaway front view showing an example of a conventional cross shaft joint. It is sectional drawing to which some cross shaft joints were expanded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cross shaft 11 Trunnion shaft 12 Inner raceway surface 13 Front end surface 2 Bearing case 21 Recessed part 22 Outer raceway surface 23 Bottom surface 3 Roller 4 Thrust washer (support guide member)

Claims (3)

  A cross shaft having a shape in which four columnar trunnion shafts are arranged in a cross shape, and four bearing cases having a bottomed cylindrical recess that individually receives each trunnion shaft, and each trunnion shaft Between the inner raceway surface provided on the outer peripheral surface of the cylinder and the outer raceway surface provided on the cylindrical inner peripheral surface of the recess of each bearing case so as to face the inner raceway surface with a certain distance therebetween. And a cross shaft joint in which a plurality of rollers are disposed with the axis thereof parallel to the trunnion shaft, and the trunnion shaft is supported and guided in each axial direction with a support guide member. The cross shaft joint, wherein the support guide member is made of a porous body having a continuous pore structure.   The cross shaft joint according to claim 1, wherein the support guide member is made of a sintered body of polyimide resin powder.   The support guide member is a thrust washer disposed between the front end surface of the trunnion shaft and the bottom surface of the recess of the bearing case, and the thrust washer is made of a porous body having a continuous pore structure. Cross shaft coupling.

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