JP2508586Y2 - Link device bearing structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improved structure of a bearing unit that is suitable for use in a steering link device of a vehicle and the like.

(Prior Art) A typical structure of a bearing portion of a steering link device in a conventional front two-axle truck will be described with reference to FIGS. 3 to 5. First, in FIG. 3, reference numeral 10 is a chassis frame of a front two-axle truck, 12 is a power steering device attached to the chassis frame 10, and 14 is a pitman arm that constitutes an output member of the power steering device 12. . Brackets 16 and 18 are attached to the chassis frame 10 at intervals in the front-rear direction of the vehicle body.
The upper ends of first and second slave levers 20 and 22 are pivotally supported at 18, respectively.

Lower end of the pitman arm 14 and the first slave lever
The lower end of 20 is connected by the first drag link 24,
The front end of the second drag link 26 is pivotally attached to the lower end of the first slave lever 20. Same second drag link 26
The rear end 26 'is pivotally connected to a front front wheel steering knuckle arm (not shown).

The first and second slave levers 20 and 22 are connected to each other at their intermediate portions by a connecting rod 28, and the intermediate portion of the second slave lever 22 has a front end of a booster 30 for power assisting the steering force. Connected,
The booster 30 has a rear end supported by a bracket 32 on the chassis frame 10. In addition, the second slave lever 22
The front end of the third drag link 34 is pivotally attached to the lower end of the, and the rear end 34 'of the drag link 34 is pivotally connected to a steering knuckle arm (not shown) for the front and rear wheels.

A detailed structure of a connecting portion of the connecting rod 28 and the booster 30 with respect to the second slave lever 22 is described in
An enlarged sectional view of the figure (a sectional view taken along line IV-IV in FIG. 3) will be described.

A first bearing hole 36 is bored in the connecting rod pivot portion of the second slave lever 22, and a cylindrical bearing bush 38 made of a proper bearing material is fitted in the bearing hole 36. On the other hand, the slave lever 22 is inserted into the forked end portion 42 having the pin hole 40 of the connecting rod 28, and a pair of side washers 44 is provided between the forked end portion 42 and the slave lever 22. The bush 38 is interposed substantially concentrically. A pin or pivot 46 is inserted through the pin hole 40 of the forked end 42, the side washer 44 and the bearing bush 38, and is fixed to the forked end 42 by a bolt 48. A grease passage 50 communicating with the inner peripheral surface of the bearing bush 38 is bored inside the pivot shaft 46, and a grease nipple 52 is attached to the inlet end of the grease passage.

Further, a second bearing hole 54 is bored in the booster pivot portion of the second slave lever 22, and a ball bush 58 is inserted into the bearing hole 54 via a spherical seat 56. On the other hand, the slave lever 22 is inserted into the forked end portion 62 having the pin hole 60 of the booster 30, and a pair of side washers 64 is provided between the forked end portion 62 and the slave lever 22 to form the ball bush. 58 or the bearing hole 54 is provided substantially concentrically. A pin or pivot 66 is inserted through the pin hole 60, the side washer 64 and the ball bush 58 of the forked end 62, and is fixed to the forked end 62 by a bolt 70. pivot
Inside the 66, the ball bush 58 and the spherical seat 56 are provided.
A grease passage 72 communicating with the internal grease oil passage is provided, and a grease nipple 74 is attached to the inlet end of the grease passage 72. The spherical sheet 56 is held in the bearing hole 54 by a snap ring 76 that is elastically fitted in a groove formed in the inner peripheral wall of the bearing hole 54.

It is possible to prevent the bearing bush 38 from being prematurely worn due to intrusion of dust, muddy water, or the like through a gap between the side washer 44 and the outer surface of the second slave lever 22 and the inner surface of the forked end portion 42. Therefore, a seal member 78 made of an elastic material such as rubber is fixed to the outer peripheral edge of the side washer 44 by baking or the like. As shown in the enlarged cross-sectional view of FIG. 5, the seal member 78 has two radially outwardly extending portions that elastically abut the outer surface of the slave lever 22 and the inner surface of the forked end portion 42. It has a seal lip 80,
In the free state, each seal lip 80 is expanded as shown by a dotted line in the figure.

Further, the side washer 64 on the booster connecting side has a seal member 82 exactly the same as the seal member 78 on the outer peripheral edge of each side washer 64.
Is stuck.

In the above configuration, when the driver operates a steering wheel (not shown) for steering, the pitman arm 14 is rotated via the power steering device 12. The rotation of the pitman arm 14 causes the first slave lever 20 to rotate around the upper end pivot via the first drag link 24, and the knuckle arm of the front front wheel is driven via the second drag link 26 to drive the front front wheel. Is steered. At the same time, the second slave lever 22 is rotated around the upper end pivot by the connecting rod 28, the knuckle arms of the front and rear wheels are driven by the third drag link 34, and the front and rear wheels are operated. Be directed. At this time, the booster 30 connected to the second slave lever 22 provides power assist for the steering force.

Since each member of the steering link device is arranged and exposed along the side rails of the chassis frame 10, it is constantly exposed to dust, muddy water, etc. while traveling.

(Problems to be Solved by the Invention) In the above conventional steering link device, FIGS.
The second slave lever 22 shown in the figure
Link) and connecting rod 28 and booster
The side washers 44 and 64 are provided to prevent the intrusion of dust, muddy water, etc. from the outside into the bearings of the pivots 46 and 66 that connect with 30 (hereinafter sometimes referred to as the second link). The sealing members 78 and 82 have a sufficient sealing effect because the sealing lip 80 elastically and strongly contacts the surfaces of the first link and the second link, that is, the vertical wall surfaces for a while after the production, but deteriorates relatively early. Then, there is a problem that the contact pressure is reduced and the sealing property is deteriorated.

In order to make up for the deterioration of the sealing performance, it is recommended to connect the grease nipples 52 and 74 provided on the pivots 46 and 66 to the centralized greasing device of the vehicle to perform grease-up prior to the start of daily work. However, it is troublesome for the user of the vehicle, and there is a problem that the consumption of grease is large and a high maintenance cost that can not be ignored is required, etc. There was a problem that the bush 58 etc. was worn early.

Further, at the time of assembly, the seal lips 80 of the seal members 78 and 82 are pressed to push the side washers 44 and 64 into the gap between the first link and the second link, and then the pivot shafts.
The work of inserting 46 and 66 is performed, but the seal lip
There was an inconvenience that it took a lot of time and effort to push in the side washers 44 and 64 without damaging the 80.

The present invention was devised in view of the above circumstances, and by improving the sealing property of the seal member mounted on the outer peripheral edge of the side washer, the grease-up interval is greatly extended and the grease consumption is reduced. It is an object of the present invention to provide a bearing portion structure of a link device which can be assembled and can be easily assembled.

(Means for Solving the Problems) In order to achieve the above object, the bearing portion structure of a link device according to the present invention has a first link and a bearing bush fitted in a bearing hole of the first link or The ball bush, the second link having one end formed with a bifurcated end portion pivotally attached to the first link, and the bearing interposed between the bifurcated end portions of the first link and the second link. A side washer disposed substantially concentrically with respect to the hole; a bearing bush or a ball bush; a side washer; and a pivot inserted through the forked end of the second link. An annular groove concentric with the bearing hole is provided on the side surface of the first link adjacent to the outer peripheral edge, and a radially inner circumferential surface of the annular groove is made of an elastic material fixed to the outer periphery of the side washer. Extend in the axial direction of the seal member The present invention is characterized in that the existing annular main lip is elastically abutted.

(Operation) According to the present invention, the annular main lip extending in the axial direction of the seal member attached to the outer peripheral edge of the side washer has a circle radially inward of the annular groove provided in the first link. By making contact with the peripheral surface, a seal joint having excellent durability is formed. Further, the main lip can be inserted into the forked end portion of the second link with the side washer attached to the first link while abutting the inner circumferential surface of the annular groove, thus facilitating the assembly. .

(Embodiment) An embodiment of the present invention will be specifically described below with reference to FIGS. 1 and 2. FIG. (Note that members or portions that are substantially the same as or corresponding to those of the conventional structure described above with reference to FIGS. 3 to 5 are denoted by the same reference numerals, and redundant description will be omitted.) For example, annular grooves 84 and 86 having a rectangular cross section are formed on the outer surface of the second slave lever 22 constituting the first link adjacent to the outer peripheral edges of the side washers 44 and 64. On the other hand, seal members 78 and 82 made of an elastic material such as rubber fixed to the outer peripheral edges of the side washers 44 and 64 by baking or the like are provided with main lips 88 extending in the axial direction, respectively. Further, in this embodiment, as clearly shown in the enlarged cross-sectional view of FIG. 2, the seal member 78 contacts the auxiliary lip 90 that abuts the outer surface of the first link 22 and the inner surface of the bifurcated end portion of the second link. Abutting auxiliary lips 92 are provided respectively, and these auxiliary lips are also provided on the sealing member 82 fixed to the outer peripheral edge of the side washer 64, as shown in FIG.

Further, in the preferred embodiment of the present invention, the side washer is used.
Sealing members 94 and 96 made of an elastic material such as rubber are also fixed to the inner peripheral edges of 44 and 64 during baking. Second
As shown in the enlarged cross-sectional view of the figure, the sealing member 94
Has two lips 98 that elastically abut the outer peripheral surface of the pivot 46.
It is equipped with The seal member 96 also has a cross-sectional shape that is substantially the same as or similar to the seal member 94.

According to the above configuration, the side washer 44 and the side washer 44 interposed between the first link 22 and the forked ends 42 and 62 of the second link are provided.
Sealing members 78 and 82 fixed to the outer peripheral edge of 64 each include a main lip 88 extending in the axial direction.
The main lips 88 of 78 and 82 resiliently abut the radially inward circumferential surface of the corresponding annular grooves 84 and 86,
The inlet end of the gap between the outer surface of the first link 22, which is the closest passage to the bearing bush 38 and the ball bush 58 for foreign matter such as dust and muddy water, and the side washers 44 and 64, which face each other, is sealed and further assisted. Additional sealing by lip 90. In addition, foreign matter such as dust and muddy water is
The auxiliary lip 92 is provided at the inlet end of the gap between the inner side surfaces of the forked ends 42 and 62 of the second link, which are bypass passages when entering the 38 and the ball bush 58, and the side washers 44 and 64, which face each other. Sealed. In addition, each seal lip 8
A very small amount of foreign matter that has passed through 8,90,92 and entered the radial invasion passage is provided by auxiliary seal members 94 and 96 attached to the inner peripheral edges of the side washers 44 and 64, respectively.
The bearing bush 38 and the ball bush 58 are further prevented from entering. These sealing members 94 and 96 are
Foreign matter that has entered in the axial direction through the gap between the 66 and the forked ends 42 and 62 of the second link is the bearing bush 38 and the ball bush.
It also has the effect of preventing reaching 58.

The most influential passage of foreign matter entering the bearing bush 38 and the ball bush 58 is sealed by mainly contacting the main seal lip 88 of the seal members 44 and 64 and the inner circumferential surfaces of the annular grooves 84 and 86. , Conventional seal lip 80
The durability of the main seal lip 88 is remarkably improved, as compared with the structure shown in FIG. 5 in which the seal is strongly abutted against the vertical wall surface. Therefore, the sealing effect of the auxiliary lips 90 and 92 and the auxiliary sealing members 94 and 96 is also added, and the time interval for grease up is greatly improved as compared with the conventional one. Since it is sufficient to increase the amount of grease, and as a result, the consumption of grease is reduced, there is an advantage that maintenance labor and cost can be significantly reduced. Further, since the side washers 44 and 64 can be inserted into the forked ends 42 and 62 of the second link while the side washers 44 and 64 are attached to the first link 22 using the main lip 88, the assembling work can be performed. There is an advantage that it can be performed more easily and quickly than before.

It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented by omitting the auxiliary lip 90 and the auxiliary seal members 94 and 96 of the seal members 78 and 82,
Even in this case, the reliability and durability of the sealing member, which are sufficiently superior to those in the past, can be ensured. Further, the present invention can be widely applied not only to the steering link device of the front two-axle vehicle illustrated but also to various link devices similarly requiring high dustproofness.

(Effects of the Invention) As described above, the bearing portion structure of the link device according to the present invention has the first link, the bearing bush or the ball bush fitted in the bearing hole of the first link, and one end. A second link having a bifurcated end portion pivotally attached to the first link and a bifurcated end portion of the first link and the second link, and being substantially concentric with the bearing hole. Of the bearing washer or ball bush, the side washer, and the pivot inserted through the bifurcated end of the second link, the side washer adjacent to the outer peripheral edge of the side washer. An annular groove concentric with the bearing hole is provided on the side surface of the first link, and an axial direction of a seal member made of an elastic material fixed to the outer periphery of the side washer is provided on a circumferential surface radially inward of the annular groove. Elastic ring main lip extending to The contact resistance is improved, and the durability and reliability of the bearing portion are improved to save the maintenance and maintenance work and to reduce the cost.

[Brief description of drawings]

1 is a sectional view of an essential part showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a portion II surrounded by a dashed line in FIG. 1, and FIG. 3 is a steering link of a conventional front two-axle vehicle. A schematic side view showing the device,
FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3 and is similar to FIG. 1, and is an enlarged sectional view of a portion V surrounded by an alternate long and short dash line in FIG. 10 ... Chassis frame, 12 ... Power steering device, 14 ...
Pitman arm, 20 ... 1st slave lever, 22 ... 2nd
Slave lever, 24 ... First drag link, 26 ... Second drag link, 28 ... Connecting rod, 30 ... Booster, 34 ... Third drag link, 42 and 62 ... Forked end, 44
& 64 ... Side washers, 46 & 66 ... Axis, 78 & 82 ...
Seal member, 84 and 86 ... Annular groove, 88 ... Main lip

Claims (1)

(57) [Scope of utility model registration request] 1. A first link, a bearing bush or a ball bush fitted in a bearing hole of the first link, and a forked end portion pivotally attached to the first link at one end. Two
Link, a side washer interposed between the forked ends of the first link and the second link and arranged substantially concentrically with the bearing hole, the bearing bush or ball bush, and a side washer. And a pivot inserted through the bifurcated end of the second link, wherein a side surface of the first link adjacent to the outer peripheral edge of the side washer is provided with an annular groove concentric with the bearing hole, An annular main lip extending in the axial direction of the seal member made of an elastic material fixed to the outer periphery of the side washer is elastically brought into contact with the radially inner circumferential surface of the annular groove. Bearing structure of the link device.