JP2004084949A - Universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a universal joint for transmitting smooth rotation by restraining looseness between a cross pin and a bearing for holding this pin. <P>SOLUTION: This universal joint 1 inserts and holds one end part of the cross-shaped cross pin 12 into and by this bearing 14 by pressing and fixing the bearing 14 in and to a pin receiving hole 13 arranged in a tip part of a connecting arm 11 for branching off one side of a yoke 10 in a bifurcated shape, and uses the bearing 14 having a tapered inner diameter contracted toward the opening side being the side for inserting the cross pin 12, and is formed into a uniform inner diameter D<SB>O</SB>over the whole width by restraining the diametral expansion caused on the opening side after being pressed in the pin receiving hole 13. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a universal joint used to connect two shafts whose axes are crossed or eccentric, such as a column shaft connected to a steering wheel and an input shaft of a steering mechanism, so that rotation can be transmitted.

2. Description of the Related Art A steering device of a vehicle transmits a rotation operation of a steering wheel by a driver inside a vehicle compartment to a steering mechanism disposed outside the vehicle compartment, and operates a steering wheel (generally used) by operating the steering mechanism. The left and right front wheels are steered. In such a steering device, it is necessary to connect the end of the column shaft, which is connected to the steering wheel and extends outside the vehicle cabin, to the end of the input shaft of the steering mechanism so that rotation can be transmitted. Since it is difficult to ensure concentricity, an intermediate shaft S configured as shown in FIG. 10 is used for this connection.

中間 As shown in the figure, the intermediate shaft S is configured by attaching universal joints (universal joints) 6 and 6 to both ends of the shaft main body. The universal joint 6 combines a pair of yokes 60, 60 such that a pair of connecting arms 61, 61 each having one side branched into two branches cross each other, and the distal ends of these connecting arms 61, 61 are combined. A known configuration is provided in which the yokes 60 and 60 are connected by a cross-shaped cross pin 62 so that rotation can be transmitted between the yokes 60 under tilting in various directions around the cross pin 62 (for example, And Patent Document 1).

In order to connect the column shaft S ₁ and the input shaft S ₂ using the intermediate shaft S, the intermediate shaft S is interposed between opposed portions of the shafts S ₁ and S ₂ , and both ends of the intermediate shaft S are connected to each other. is realized said column shaft S ₁ and the input shaft S ₂ is fitted held to the rest of the yoke 60, 60 of the universal joint 6,6. In such a connection under The column shaft S ₁ or the input shaft S ₂ and the intermediate shaft S, it is possible to tilt freely tip of cross pin 62 of the universal joint 6, 6 interposed between each as pivot, The rotation of the column shaft S _{1 in} a state where the tilt angle does not exceed the predetermined angle is transmitted to the input shaft S ₂ via the intermediate shaft S by the action of the universal joints 6 at both ends, and the input shaft S ₂ It rotates around the axis, and rotation is transmitted between both axes S ₁ and S ₂ .
JP 2001-193753 A

FIG. 11 is a cross-sectional view taken along the line XI-XI in FIG. 10 showing a connecting portion of the yokes 60, 60 in the universal joint 6. As shown in the figure, the cross pin 62 has four pin portions 62a, 62a,. Pin holding holes 63, 63 are coaxially opposed to the distal ends of the pair of connecting arms 61, 61 branched at one side of the yokes 60, 60 so as to pass through the center of the yoke 60. The bearings 64, 64 are press-fitted and fixed to these, respectively.

As shown in the figure, the yokes 60 are connected to the pin holding holes 63 of the one yoke 60 so as to project from the four pin portions 62a, 62a,. The pair of pin portions 62a, 62a are inserted, and the other pair of pin portions 62a, 62a are inserted into the pin holding holes 63, 63 of the other yoke 60, and press-fit into the respective pin holding holes 63, 63,. The bearings 64, 64,...

As described above, as the bearing 64 for holding the pin portion 62a of the cross pin 62, as shown in the drawing, a pin is used for the purpose of keeping the radial dimension small and preventing foreign matter such as dust from entering the holding portion. Needle bearings having a cup-shaped outer ring that is open only on the side where the portion 62a is inserted are widely used. However, when such a bearing 64 is used, the following problem occurs.

FIG. 12 is an explanatory view of a problem in the conventional universal joint, in which a portion where the bearing 64 is fitted into the pin holding hole 63 is shown in an enlarged manner. As shown in the figure, the bearing 64 press-fitted and fixed in the pin holding hole 63 may be deformed so that the open side of the outer ring expands in diameter. In such a state, as shown by a two-dot chain line in the figure. A gap is formed between the pin section 62a and the outer peripheral surface of the pin section 62a to be inserted. When such an assembling is performed, rattling occurs due to the influence of the gap with rotation transmission.

Such backlash inhibition of smooth rotation, generation of local wear, over which lead to various problems such as the occurrence of abnormal noise, the steering apparatus for a vehicle described above, the column shaft S ₁ and the steering when used in applications for connecting the input shaft S ₂ mechanism taken, the driver operating the steering wheel is experience a lack of rigidity feeling by backlash, the drawback that lead to degradation of the steering feeling there were.

Note that this difficulty can be solved by making the width of the bearing 64 smaller than the length of the pin holding hole 63 and performing the press-fitting of the bearing 64 under the constraint over the entire width. When the width is narrowed, there is a problem that the durability is deteriorated due to a decrease in the load capacity of the bearing 64. Conversely, when the length is realized by increasing the length of the pin holding hole 63, the pin 64 is provided. There is a problem that the yoke 60 becomes large in size, and it becomes difficult to apply the yoke 60 to applications in which the arrangement space is limited, such as the above-described steering device for a vehicle.

In addition, the diameter of the opposite side of the outer ring of the bearing 64 press-fitted into the pin holding hole 63 decreases with the diameter increase on the opening side, and the pin portion 62a inserted into such a bearing 64 includes: An interference is provided on the non-open side. Accordingly, the needle, which is the rolling element of the bearing 64, has a gap on the open side (A in FIG. 12) of the outer ring, and has a pin on the non-open side (B in FIG. 2). Rolling occurs in a state of contact with the portion 62a, and there is a problem that each needle is inclined with respect to the normal rotation axis and smooth rolling is hindered, that is, so-called skew easily occurs.

The present invention has been made in view of such circumstances, and effectively prevents generation of a gap between a pin portion of a cross pin and a bearing that holds the cross pin, with a simple configuration, and has a play during rotation transmission, It is another object of the present invention to provide a universal joint which does not cause various problems.

The universal joint according to the first invention of the present invention is characterized in that a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end portion of a connection arm formed by branching one side of a yoke into two branches, and a pin of a cross-shaped cross pin is fixed to the bearing. In the universal joint having a portion inserted and held, the bearing has a tapered inner diameter reduced toward a side where the pin portion of the cross pin is inserted.

In the first invention, as a bearing for holding a pin portion of the cross pin, a bearing having an inner diameter tapered toward the insertion side of the cross pin is used, and a pin receiving hole at a tip of a connecting arm on one side of the yoke is used. The diameter of the reduced-diameter portion is increased by press-fitting so that the inner diameter becomes uniform after press-fitting, and the pin portion of the cross pin inserted in this state is held without gaps over the entire length, causing rattling. To prevent When a general needle bearing is used as the bearing, the above-described reduction in the inner diameter can be realized by using a needle that expands in a tapered shape toward the insertion side of the cross pin.

A universal joint according to a second aspect of the present invention is characterized in that a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end portion of a connecting arm formed by branching one side of a yoke into two branches, and a pin of a cross-shaped cross pin is fixed to the bearing. In the universal joint in which the portion is inserted and held, the pin receiving hole is a tapered hole which is tapered toward the side where the pin portion of the cross pin is inserted.

In the second invention, the pin receiving hole into which the bearing for holding the pin portion of the cross pin is press-fitted is formed as a tapered hole whose diameter decreases toward the insertion side of the cross pin, and the bearing is expanded by press-fitting into the pin receiving hole. The diameter is suppressed by the reduced diameter portion of the pin receiving hole, so that the bearing has a uniform inner diameter in a state after press-fitting, and the pin portion of the cross pin inserted in this state is held without a gap over the entire length, and is loose. Prevents sticking.

A universal joint according to a third invention of the present invention is characterized in that a bearing is press-fitted and fixed in a pin receiving hole provided at a tip end of a connecting arm that branches one side of a yoke into two branches, and a pin of a cross-shaped cross pin is fixed to the bearing. In the universal joint in which the portion is inserted and held, the pin portion of the cross pin is tapered toward the tip end.

In the third invention, the pin portion of the cross pin is tapered toward the distal end so as to have a reduced diameter, and is inserted into the bearing whose diameter is enlarged by press-fitting the distal end of the connecting arm into the pin receiving hole. It is held without gaps over the entire length to prevent rattling.

The universal joint according to a fourth aspect of the present invention is the universal joint according to the third aspect, wherein the tapered portion of the pin portion has a diameter reduced from the tip of the pin portion to the bearing. It is characterized by being provided.

In the fourth invention, the pin portion of the cross pin is shaped so as to be reduced in diameter toward the distal end while leaving a suitable length of an equal diameter portion on the base end side, and the pin is inserted into the bearing press-fitted into the pin receiving hole at the distal end of the connecting arm. At the time of assembling to insert the part, the needle, which is the rolling element of the bearing, stands up substantially in parallel with the axis of the pin part by contact with the equal-diameter part, and acts in synergy with the reduced-diameter part at the tip of the pin part. On the side opposite to the open side, the interference given to each needle is reduced, and the phenomenon that these needles are tilted with respect to the normal rotation axis, that is, so-called skew is suppressed. In addition, the reduced diameter portion provided on the pin portion reduces the contact of the bearing with the needle when inserted into the bearing, suppresses the occurrence of scratches on the needle and the pin portion, and improves the assemblability. Make

A universal joint according to a fifth aspect of the present invention is characterized in that a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end of a connecting arm formed by branching one side of a yoke into two branches, and a pin of a cross-shaped cross pin is fixed to the bearing. In the universal joint in which the parts are inserted and held, at least a pair of pin parts projecting in the opposite direction of the cross pin or at least a pair of pin receiving holes into which these are inserted are eccentric to each other.

In the fifth invention, one or both of the two pairs of pin portions of the cross pin projecting in opposite directions, or one or both of the two pairs of pin receiving holes into which these pin portions are inserted, are appropriately eccentric. When the pin portion is inserted into a bearing whose open side is enlarged in diameter by press-fitting into the pin receiving hole, the pin portion is inclined inside the respective bearing and abuts on the open side and the inner side. It is held in the state of being shaken to prevent rattling.

In a universal joint according to a sixth aspect of the present invention, a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end of a connecting arm formed by branching a side of a yoke into two branches, and a pin of a cross-shaped cross pin is fixed to the bearing. At least one pair of pin portions projecting in the opposite direction of the cross pin, or at least a pair of pin receiving holes into which these are inserted, are formed with axes that intersect each other. It is characterized by having.

In the sixth invention, one or both of the two pairs of pin portions of the cross pin projecting in opposite directions, or one or both of the two pairs of pin receiving holes into which these pin portions are inserted, respectively, When the pin portions are inserted into the bearings whose diameters are formed by press fitting into the pin receiving holes, the inner surfaces of the respective bearings have a predetermined inclination angle. And is held in a contact state to prevent rattling.

In the universal joint according to the present invention, it is possible to effectively prevent rattling between the cross pin that connects the yokes and the bearing that holds the yokes, and make it possible to transmit rotation between the yokes satisfactorily. For example, when the present invention is used to connect a column shaft and an input shaft to a steering mechanism in a vehicle steering system, the present invention has excellent effects such that a smooth steering feeling without being caught can be obtained.

  Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a side view showing a first embodiment of the universal joint according to the present invention. In the universal joint 1 shown in this figure, like the conventional universal joint 6, a pair of yokes 10, 10 are combined such that a pair of connecting arms 11, 11 each having one side branched into two branches, cross each other. These tips are connected by a cross pin 12, and between the yokes 10, 10 and a shaft (not shown) held on the other side by tilting the cross pin 12 in various directions with the cross pin 12 as a pivot. It is configured to transmit rotation.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1 and shows the connecting structure of the yokes 10, 10. As shown in this figure, a pair of connecting arms 11, 11 branched on one side of the yokes 10, 10 are respectively provided with pin receiving holes 13, which are formed radially through the distal ends facing the center of the yoke 10. , 13 to which separate bearings 14, 14,... Are press-fitted and fixed.

The cross pin 12 used for connecting the connecting arms 11, 11 has a cross shape having four pin portions 12a, 12a,. As shown in the figure, a pair of pin portions 12a, 12a projecting in opposite directions among the four pin portions 12a, 12a are provided on a connecting arm 11, 11 of one yoke 10, as shown in the drawing. The other pair of pin portions 12a and 12a are inserted into the pin receiving holes 13 and 13 provided in the connecting arms 11 and 11 of the other yoke 10, respectively. , 13.. Are held by bearings 14, 14.

Like the bearings 64, 64 ... in the conventional universal joint 6, these bearings 14, 14 ... keep the radial dimension small and prevent foreign matter such as dust from entering the holding portion of the cross pin 12. For the purpose, as shown, a needle bearing having a cup-shaped outer ring in which only the side into which the pin portion 12a of the cross pin 12 is inserted is opened is used.

FIG. 3 is an explanatory view of a characteristic portion of the universal joint 1 shown in FIGS. 1 and 2, and shows a fitting portion of the bearing 14 into the pin receiving hole 13. In this embodiment, each bearing 14 has the following characteristic configuration so that the pin portions 12a of the cross pin 12 are held by the bearings 14, 14 without any gap. . As shown in FIG. 3 (a), the bearing 14 is press-fitted from one side of the pin receiving hole 13 with the open side for inserting the pin portion 12a of the cross pin 12 first, and as shown in FIG. 3 (b) and FIG. , With the open side protruding an appropriate length.

FIG. 3A shows the bearing 14 before being pressed into the pin receiving hole 13. The bearing 14 as illustrated, the inner diameter D ₁ of the side (open side) of the pin portion 12a of the cross pin 12 is inserted is smaller than the inner diameter D ₂ of the other side, the inner diameter is reduced to a tapered shape toward the open side It is configured to have. When such a bearing 14 is pressed into the pin receiving hole 13 as shown in FIG. 3B, the diameter of the bearing 14 is reduced in accordance with the interference between the two. small in the open side of a result of the open side in a state of being relatively enlarged, as shown, will have an inside diameter D ₀ substantially uniform over the entire width.

Accordingly, the pin portion 12a of the cross pin 12 inserted into the bearing 14 is uniformly held without a gap over the entire width of the bearing 14, and the yokes 10, 10 are not accompanied by the play caused by the gap. It is possible to perform rotation transmission between them. The universal joint 1 configured as described above is used for connecting the column shaft S ₁ and the input shaft S _{2 of the} steering mechanism in a vehicle steering system, similarly to the conventional universal joint 6 shown in FIG. In this case, the driver operating the steering wheel does not experience the discomfort caused by the rattling, and a smooth and good steering feeling can be obtained.

The reduction of the inner diameter of the bearing 14 may be realized by increasing the thickness of the outer ring holding the needle toward the open side, as shown in the drawing, or by reducing the diameter of the needle that is tapered toward the open side. It may be realized by use. Further, the bearing 14 is not limited to the needle bearing shown in the embodiment, but may be a sliding bearing. In this case, it is needless to say that the same effect can be obtained by adopting the above-described inner diameter change. . In FIG. 3, for convenience of explanation, is shown to increase the difference between the inner diameter D ₂ of the open side of the inner diameter D ₁ and the opposite side of the bearing 14, the difference between the actual therebetween is slight, This difference is set according to the degree of diameter reduction and diameter expansion actually generated in the bearing 14 by press fitting into the pin receiving hole 13.

  FIG. 4 is an explanatory view of a characteristic portion of the second embodiment of the universal joint according to the present invention, and shows a fitting portion of the bearing in the pin receiving hole, as in FIG. The overall configuration of the universal joint 2 shown in this embodiment is the same as that of the universal joint 1 shown in FIGS. 1 and 2 according to the first embodiment, and the features thereof are similar to those of the first embodiment. The holding structure of the pin portion 22a of the cross pin 22 is formed in the pin receiving hole 23 at the tip of the connecting arm 21 via the bearing 24.

As shown in FIG. 4 (a), the bearing 24 is press-fitted from one side of the pin receiving hole 23 with the open side for inserting the pin portion 22a of the cross pin 22 first, and as shown in FIG. Are fitted in a state where they are projected to an appropriate length. FIG. 4A shows the pin receiving hole 23 before the bearing 24 is press-fitted. Pin receiving hole 23 as illustrated, the inner diameter D ₃ on the side where the pin 22a is inserted is smaller than the inner diameter D ₄ of the other side, a tapered hole whose diameter is reduced in a tapered shape toward the insertion side of the pin portion 22a Is formed.

When the bearing 24 is press-fitted into such a pin receiving hole 23 as shown in FIG. 4B, the bearing 24 is tightened between the pin receiving hole 23 and the pin receiving hole 23 within the length range thereof. The diameter is reduced according to the margin, and the diameter is relatively increased on the open side protruding from the pin receiving hole 23. On the other hand, the interference between the pin receiving hole 23 formed as a tapered hole is large on the open side of the bearing 24, and the diameter expansion described above is suppressed. bearing 24 will have an inner diameter D ₀ substantially uniform over the entire width.

Therefore, the pin portion 22a of the cross pin 22 inserted into the bearing 24 is uniformly held without a gap over the entire width of the bearing 24, and performs the rotation transmission without the backlash caused by the gap. It is possible to make it. Universal joint 2 having such a holding structure, similar to the conventional universal joint 6 shown in FIG. 10, is used in applications for connecting the input shaft S ₂ of the column shaft S ₁ and the steering mechanism in the vehicle steering system In this case, the driver operating the steering wheel does not experience the discomfort caused by the rattling, and a smooth and good steering feeling can be obtained.

In FIG. 4, for convenience of explanation, is shown to increase the difference between the both sides of the inside diameter D ₃ and D ₄ of the pin receiving hole 23, the difference between the actual therebetween is slight, this difference The diameter is set in accordance with the degree of diameter reduction and diameter expansion actually generated in the bearing 24 by press fitting into the pin receiving hole 23.

  FIG. 5 is an explanatory view of a characteristic portion of the third embodiment of the universal joint according to the present invention, in which the fitting portion of the bearing into the pin receiving hole is shown as in FIGS. I have. The overall configuration of the universal joint 3 shown in this embodiment is the same as that of the universal joint 1 shown in the first embodiment of FIGS. 1 and 2, and its features are the first and second embodiments. Similarly to the above, there is a holding structure for the pin portion 32a of the cross pin 32 formed in the pin receiving hole 33 at the tip of the connecting arm 31 via the bearing.

As shown in FIG. 5 (a), the bearing 34 is a needle bearing having a cup-shaped outer ring that is open only on the side where the pin portion 32a of the cross pin 32 is inserted, and has the same inner diameter over the entire width. With the open side first, it is press-fitted from one side of the pin receiving hole 33 and, as shown in FIG. When such a bearing 34 is press-fitted into the pin receiving hole 33, its diameter is reduced in accordance with the interference between the two. However, the degree of this diameter reduction is small on the open side protruding from the pin receiving hole 33, as shown in FIG. as (b), the open side is relatively expanded, the inner diameter D ₆ of the open side is larger than the inner diameter D ₅ of the other side (innermost side).

In the third embodiment, the dimensions of the pin portions 32a of the cross pins 32 inserted and held in the bearings 34 are set in anticipation of the deformation of the bearings 34 generated as described above. the inner diameter of the open side substantially equal to the inner back side of the inner diameter D ₅ which is a modification of the outer diameter, also a variation of the outer diameter of the base of the pin portion 32a located on the open side of the bearing 34 of the tip to reach the innermost side and equal to D _6, as shown in FIG. 5 (a), it is configured to have an outer diameter reduced in a tapered shape toward the tip side.

After being inserted into the bearing 34 that has been deformed as described above, such a pin portion 32a is uniformly held without a gap over the entire width of the bearing 34, and without any play caused by the gap. Rotation transmission can be performed. The universal joint 3 having the holding structure of such a cross pin 32, similarly to the conventional universal joint 6 shown in FIG. 10, for connecting the input shaft S ₂ of the column shaft S ₁ and the steering mechanism in the vehicle steering system In this case, the driver operating the steering wheel does not experience the discomfort due to the rattling, and a smooth and good steering feeling can be obtained.

In FIG. 5, for convenience of explanation, it is shown to increase the difference between the outer diameter D ₆ of the outer diameter D ₅ and the base of the tip portion of the pin portion 32a, but the difference between the actual therebetween is small .

  FIG. 6 is an explanatory view of a characteristic portion of a fourth embodiment of the universal joint according to the present invention, in which a fitting portion of a bearing to a pin receiving hole is shown as in FIGS. I have. In this embodiment, the pin portion 32a of the cross pin 32 is provided with a reduced diameter portion 32b tapered toward the tip similarly to the embodiment shown in FIG. Is formed over substantially half the length of the pin portion 32a so as to be continuous with the constant diameter portion 32c on the base end side. The configuration of the other parts is the same as that of the embodiment shown in FIG. 5, and the corresponding parts are denoted by the same reference characters and description thereof is omitted.

As shown by an arrow in FIG. 6A, such a pin portion 32a is inserted into a bearing 34 press-fitted and fixed in a pin receiving hole 33 at the tip of the connecting arm 31, and shown in FIG. 6B. Is maintained as such. At this time, a part of the equal-diameter portion 32c continuous to the base end side of the reduced-diameter portion 32b is also inserted into the bearing 34, and the bearing 34 having the outer ring whose open side is enlarged in diameter by press-fitting into the pin receiving hole 33 is inserted. The needles are rolled in contact with the needles arranged on the inner side, and these needles are erected so as to be substantially parallel to the axis of the pin portion 32a.

  Such a rolling contact state of the equal-diameter portion 32c is obtained by setting the length of the reduced-diameter portion 32b shorter than the length of insertion into the bearing 34, and is synergistic with the reduced-diameter portion 32b at the tip of the pin portion 32a. By the action, the interference given to each needle on the side opposite to the opening of the bearing 34 is alleviated, and the phenomenon that these needles are inclined with respect to the normal rotation axis, so-called skew, can be effectively suppressed. In addition, the reduced diameter portion 32b at the tip of the pin portion 32a acts to ease the contact of the bearing 34 with the needle when inserted into the bearing 34, so that it is possible to prevent damage to each needle and the pin portion 32a during assembly. In addition, the assemblability can be greatly improved.

Further, as described above, the reduced diameter portion 32b at the tip of the pin portion 32a is uniformly held without any gap by the bearing 34 which is deformed so as to expand the open side by press-fitting into the pin receiving hole 33, and is accompanied by rotation transmission. It acts to prevent sticking. Therefore, when used in order to connect the input shaft S ₂ of the column shaft S ₁ and the steering mechanism in the vehicle steering system, the synergism with suppression of skew described above, the driver uncomfortable feeling to the steering wheel No sensation is felt, and a smooth and good steering feeling can be obtained.

  FIG. 7 is an explanatory view of a characteristic portion of a universal joint according to a fifth embodiment of the present invention, and FIG. 8 is an explanatory diagram of a characteristic portion of a universal joint according to a sixth embodiment of the present invention. These show plan views of cross pins used for connecting the yokes.

The cross pin 42 shown in FIG. 7 includes four pin portions 42a, 42a... Protruding in directions orthogonal to each other in one plane, and has a cross shape. The pair of pin portions 42a, 42a projecting in the opposite direction are not coaxial but are eccentric with a small eccentricity α.

The cross pin 52 shown in FIG. 8 is provided with four pin portions 52a, 52a... Protruding in different directions on one surface, and is configured to have a cross shape. Each pair of pin portions 52a, 52a projecting in the direction is not coaxial but has an axis that intersects at a small intersection angle β as shown in the figure.

9 (a) is an operation explanatory view of the universal joint 4 including the cross pin 42 shown in FIG. 7, and FIG. 9 (b) is an operational explanatory view of the universal joint 5 including the cross pin 52 shown in FIG. These are skeleton diagrams showing a state in which the cross pins 42, 52 contact the bearings 44, 54 at the tips of the connecting arms 41, 51, and the bearings 44, 54 are integrally shown at the tips of the connecting arms 41, 51. However, as in the case of the first and second embodiments, actually, they are press-fitted and fixed to pin receiving holes (not shown) provided in the connecting arms 41 and 51.

In the universal joint 4 shown in FIG. 9 (a), the pin portions 42a, 42a of the cross pin 42 inserted and held in the bearings 44, 44 at the tip of the connecting arm 41, as shown in FIG. They come into contact with the inner surfaces of the separate bearings 44, 44 at two locations, as shown, on the open side and the inner side. Therefore, even if a large diameter portion is formed on the open side of the bearings 44, 44 due to press-fitting into the pin receiving hole, the pin portions 42a, 42a may rattle in the bearings 44, 44. And the rotation can be smoothly transmitted. Note that, instead of eccentricity of both ends of the cross pin 42, the pin receiving holes into which these are inserted may be eccentric, and it goes without saying that the same effect can be obtained.

In the universal joint 5 shown in FIG. 9B, the pin portions 52a of the cross pin 52 which are inserted and held in the bearings 54 at the tip of the connecting arm 51, as shown in FIG. These are inclined in the bearings 54, 54 into which they are inserted, and come into contact with two points on the open side and the inner side as shown in the figure. Therefore, even if a large-diameter portion is formed on the open side of the bearings 54, 54 due to press-fitting into the pin receiving holes, the pin portions 52 a, 52 a may rattle in the bearings 54, 54. Therefore, it is possible to smoothly transmit the rotation. Instead of crossing the axes of both ends of the cross pin 52, the pin receiving holes into which these are inserted may be formed so that the respective axes cross each other, whereby exactly the same effect can be obtained. Needless to say.

7 to 9, for the sake of explanation, the eccentric amount α of the pin portions 42a and 42a of the cross pin 42 and the cross angle β of the pin portions 52a and 52a of the cross pin 52 are shown to be large. Both values are minute values, and are set according to the degree of diameter reduction and diameter expansion actually generated in the bearing 44 or the bearing 54 by press fitting into the pin receiving hole. Above-described universal joint 4 and 5, be used in applications for connecting the input shaft S ₂ of FIG. 10 in the same manner as conventional universal joint 6 shown, the column shaft S ₁ and the steering mechanism in the vehicle steering system In this case, the driver operating the steering wheel does not experience the above-mentioned uncomfortable feeling due to rattling, and a smooth and good steering feeling can be obtained.

It is a side view showing a 1st embodiment of a universal joint concerning the present invention. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 3 is an explanatory diagram of a characteristic portion of the universal joint shown in FIGS. 1 and 2. It is explanatory drawing of the characteristic part of 2nd Embodiment of the universal joint which concerns on this invention. It is explanatory drawing of the characteristic part of 3rd Embodiment of the universal joint which concerns on this invention. It is explanatory drawing of the characteristic part of 4th Embodiment of the universal joint which concerns on this invention. It is explanatory drawing of the characteristic part of 5th Embodiment of the universal joint which concerns on this invention. It is explanatory drawing of the characteristic part of 6th Embodiment of the universal joint which concerns on this invention. FIG. 9 is an operation explanatory view of the universal joint shown in FIGS. 7 and 8. FIG. 4 is a side view of an intermediate shaft used to connect a column shaft and a steering mechanism in a vehicle steering system. FIG. 11 is a transverse sectional view taken along line XI-XI in FIG. 10. It is explanatory drawing of the problem in the conventional universal joint.

Explanation of reference numerals

1, 2, 3, 4, 5 Universal joint 10 Yoke 11, 21, 31, 41, 51 Connecting arm 12, 22, 32, 42, 52 Cross pin 13, 23, 33 Pin receiving hole 14, 24, 34, 44, 54 Bearing 12a, 22a, 32a, 42a, 52a Pin 32b Reduced diameter (tapered diameter reduced)

Claims (6)

In a universal joint, a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end portion of a connecting arm formed by branching one side of a yoke into two branches, and a pin portion of a cross-shaped cross pin is inserted and held in the bearing.
The universal joint according to claim 1, wherein the bearing has a tapered inner diameter reduced toward a side where the pin portion of the cross pin is inserted. In a universal joint, a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end portion of a connecting arm formed by branching one side of a yoke into two branches, and a pin portion of a cross-shaped cross pin is inserted and held in the bearing.
The universal joint according to claim 1, wherein the pin receiving hole is a tapered hole whose diameter is reduced in a tapered shape toward a side where the pin portion of the cross pin is inserted. In a universal joint, a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end portion of a connecting arm formed by branching one side of a yoke into two branches, and a pin portion of a cross-shaped cross pin is inserted and held in the bearing.
The universal joint according to claim 1, wherein a pin portion of the cross pin is tapered toward a tip end. 4. The universal joint according to claim 3, wherein the tapered portion of the pin portion is provided over a length range shorter than a length of insertion from the tip of the pin portion into the bearing. 5. In a universal joint, a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end portion of a connecting arm formed by branching one side of a yoke into two branches, and a pin portion of a cross-shaped cross pin is inserted and held in the bearing.
At least one pair of pin portions projecting in the opposite direction of the cross pin, or at least one pair of pin receiving holes into which these are inserted, are eccentric to each other. In a universal joint, a bearing is press-fitted and fixed in a pin receiving hole provided at a distal end portion of a connecting arm formed by branching one side of a yoke into two branches, and a pin portion of a cross-shaped cross pin is inserted and held in the bearing.
A universal joint, wherein at least a pair of pin portions projecting in the opposite direction of the cross pin or at least a pair of pin receiving holes into which these are inserted are formed to have axes that cross each other.

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