JPH0444895Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a bearing that rotatably supports a rotating shaft.

[Conventional technology]

Conventionally, in bearing devices such as automobile steering columns, rubber bearings have been used in place of radial ball bearings in order to rotatably support a rotating shaft such as a steering shaft in a housing. This bearing consists of a cylindrical body made of an elastic material such as rubber, and has a spline section engraved in the axial direction on its outer circumferential surface, and a double row in the axial direction and a uniform row in the circumferential direction on the inner circumferential surface. A wavy portion having a plurality of ridges and troughs is formed on the inner diameter, and the ridges abut and support the rotating shaft. The valleys serve as grease reservoirs.

[Problem that the invention attempts to solve]

However, according to the above-mentioned conventional rubber bearings, there are large variations in dimensions due to molding or environmental temperature, which causes problems such as misalignment with the rotating shaft, settling, and rattling of the rotating shaft. Therefore, if a tightening allowance is provided to eliminate play with the rotating shaft, the rotational torque of the rotating shaft will increase significantly, and conversely, if the tightening allowance is eliminated, although the rotational torque will be lower, play will occur. In order to solve this problem, a proposal was made to reduce the rotational torque by making the inner diameter of the part of the peak that slides in contact with the rotating shaft larger than the other part, thereby reducing the pressure contact part. No. 156533) was made.

However, although this proposal solved the above problems, the small diameter ridges (high ridges) would wear out and the rotating shaft would be supported by the large diameter ridges (low ridges). Until this happens, the rotational torque must gradually increase. In other words, the small-diameter peak that initially contacts the rotating shaft has a wave-shaped cross-section, so it is a point contact, but when the top wears out, it changes to a surface contact, and the contact surface gradually expands due to wear. , there is a problem that the rotational torque fluctuates.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a bearing made of a cylindrical elastic body having an outer circumferential part that can be integrally attached to a housing and an inner circumferential part into which a rotating shaft is inserted. Valleys or peaks and flat surfaces are formed alternately and continuously in the axial direction,
A bearing is constructed by forming a protrusion consisting of an annular band having a constant thickness and a constant height and a rectangular cross section at the top of the mountain portion.

[Effect]

According to the present invention, the rotating shaft is supported in contact with the protrusion, and since the protrusion has a constant width, a constant contact surface can always be maintained even when the protrusion wears out. Even if wear progresses, a constant pressure contact is always maintained, the rotational torque does not fluctuate, and rattling due to wear is prevented.

In addition, since the protrusions are provided on the tops of the ridges, even if the ridges wear out, the tops of the ridges perform the same function as the ridges, extending the life of this type of bearing.
Furthermore, the grooves improve the circulation of lubricant and prevent wear of the protrusions. Furthermore, if the protrusions are made of Teflon resin, wear resistance will be improved.

〔Example〕

The present invention will be explained below based on the illustrated embodiments.

Figure 1 is a perspective external view, Figure 2 is a half-section side view,
Figure 3 is a cross-sectional side view of the state in use, Figures 4 to 6
The figures are sectional views of main parts showing other embodiments.

1 to 3, a cylindrical bearing body 1 made of an elastic material such as rubber has a spline portion 2 continuously carved in the thrust direction on its outer peripheral surface. On the other hand, a wavy portion 5 is formed on the inner circumferential surface in which a ridge portion 3 and a trough portion 4 are continuous at regular intervals in the axial direction. A surface layer portion 6 made of Teflon-based synthetic resin is attached to the surface of the corrugated portion 5. A protrusion 7 made of a rectangular annular band having a constant thickness and a constant height is integrally formed on the top of the mountain portion 3. Note that the protrusion 7 may be formed integrally with the peak portion 3 using the same material.

Furthermore, a stopper 8 is formed protrudingly on the spline portion 2, and as shown in FIG. Position the main body 1.

Next, the operation of the above embodiment will be explained based on FIG. The bearing body 1 is press-fitted into the housing 9 in the axial direction, and the stopper 8 is fitted into the hole 10 of the housing 9. Since the outer diameter of the bearing body 1 is larger than the inner diameter of the housing 9, the bearing body 1 is pressed against the housing 9 after assembly, and has the stopper 8 fitted in the hole 10, so that the housing 9 and It is installed integrally.

Therefore, when the rotating shaft 11 is inserted into the bearing body 1 in the axial direction, the rotating shaft 11 comes into contact with the protrusion 7 and is rotatably supported. Note that a lubricant such as grease is applied to the valley portions 4, and the lubricant circulates through the valley portions 4 to lubricate the protrusions 7 and the peak portions 3. Since the protrusion 7 is an annular band having a rectangular cross section with a constant thickness and a constant height, even if it is worn by the rotating shaft 11, it always maintains the same contact area. When the protrusion 7 is completely worn out, the rotating shaft 11 is supported by the top of the peak 3.

To explain the second embodiment shown in FIG. 4, the inner peripheral surface of the bearing body 1 in this embodiment has grooves 12 cut out across the protrusions 7 and the peaks 3 at regular intervals in the circumferential direction. It is set up. The groove portion 12 is discontinuous in the axial direction so as to communicate only the valley portions 4 located on both sides of the peak portion 3, and has a mutual phase difference. The other configurations are similar to those of the embodiment shown in FIGS. 1 to 3, and the same or corresponding components are denoted by the same reference numerals and redundant explanation will be omitted.

According to the second embodiment, the lubricant applied to the troughs 4 flows along the troughs 4 as the rotating shaft 11 rotates, and also flows through the grooves 12 and flows through the troughs on both sides of the peaks 3. 4.Be mutually integrated between 4 and 4. Therefore,
The lubricant in the corrugated portion 5 is made uniform, and thus the protrusion 7
The peak portion 3 is prevented from uneven wear by the lubricant which is not unevenly distributed. Therefore, wear on the protrusions 7 and the peaks 3 is reduced.

To explain the third embodiment shown in FIG. 5, the wavy portion 5 in this example has ridges 3a, 3a located at both ends thereof, which are formed to protrude inward higher than the other ridges 3. In addition, a protrusion 7 is formed at the top of each of these peaks 3 and 3a, and a groove 12 cut out across the protrusion 7 and the peak 3 is cut in the same way as in the previous example. The other configurations are the same as those of the second embodiment, and the same reference numerals are used for the same or corresponding components, and redundant explanation will be omitted.

According to the third embodiment, the protrusions 7 of the peaks 3a, 3a initially support the rotating shaft 11, and when the protrusions 7 wear out, the tops of the peaks 3a, 3a support the rotating shaft 11.
1 is supported, and when the ridges 3a and 3a wear out, the rotating shaft 11 is supported by the protrusion 7 of the other ridge 3, and after this ridge 7 wears out, the rotating shaft 11 is supported by the top of the ridge 3. 11 is supported. In addition, the mountain portions 3a, 3
A acts as a seal to prevent the lubricant applied to the valley portion 4 from leaking.

Explaining the fourth embodiment shown in FIG. 6, the wavy portion 5 in this example is constituted by mountain portions 3 and flat portions 13 that alternately continue in the thrust direction. The other configurations are the same as those in the second and third embodiments, and the same reference numerals are used for the same or corresponding components, and redundant explanation will be omitted.

According to the fourth embodiment, the peaks 3, 3 of the wavy portion 5
Since the lubricant accumulates in between and the flat portion 13 is different from the valley portion 4 as in the previous example, the distance from the top of the protrusion 7 or the peak portion 3 to the lubricant is shortened, and the time rate at which the lubricant lubricates is reduced. speed up. Moreover, the cost required for molding is low.

[Effect of idea]

According to the present invention described above, in a bearing made of a cylindrical elastic body having an outer circumferential portion that can be integrally attached to a housing and an inner circumferential portion into which a rotating shaft is inserted, the inner circumferential portion has peaks and troughs. Alternatively, peaks and flat surfaces are formed alternately and continuously in the axial direction, and a protrusion consisting of an annular band with a constant thickness and a constant height and a rectangular cross section is formed at the top of the peak. Even if the contact surface with the rotating shaft wears out, the ridges will always support the rotating shaft with a constant contact surface, so the rotational torque will always be constant until the ridges are completely worn out. can be maintained.

Furthermore, even if the protrusions are completely worn out, the tops of the ridges perform the same function as the protrusions, so a product with a long life that can prevent rotational torque from increasing over a long period of time can be obtained, and rattling can be prevented. .

In addition, the grooves formed by the notches that cross the protrusions or the protrusions and the ridges promote the distribution of the lubricant applied between the protrusions or the ridges, so that the lubricant is uniformly distributed on the inner circumferential surface. None, improves lubrication performance,
Prevent uneven wear.

Furthermore, since the grooves are discontinuous in the axial direction of the bearing body, the grooves are prevented from becoming sagging, so providing the grooves has the effect that no damage is caused.

[Brief explanation of the drawing]

Figure 1 is a perspective view, Figure 2 is a half-section side view, and Figure 3 is a perspective view.
The figure is a sectional side view of the device in use, and FIGS. 4 to 6 are sectional views of essential parts showing other embodiments. 1...Bearing body, 2...Spline part, 3, 3
a... Mountain part, 4... Valley part, 5... Wavy part, 6...
Surface layer portion, 7... Projection, 11... Rotating shaft, 12...
Groove portion, 13...Flat surface.

Claims (1)

[Scope of claims for utility model registration] (1) An outer peripheral portion that can be integrally attached to the housing;
In a bearing made of a cylindrical elastic body having an inner circumferential portion into which a rotating shaft is inserted, the inner circumferential portion is formed of peaks and valleys or peaks and flat surfaces alternately and continuously in the axial direction. . A bearing characterized in that a protrusion consisting of an annular band having a constant thickness and a constant height and a rectangular cross section is formed at the top of the mountain portion. (2) The bearing according to claim 1, wherein the peaks have the same height. (3) The height of the ridges is such that the ridges located at both ends of the inner circumference are higher than the other ridges and protrude inwardly. The bearing described in item 1. (4) The bearing according to claim 1, wherein the protrusion is made of Teflon-based synthetic resin. (5) The bearing according to claim 1 or 4 of the utility model registration claim, characterized in that the protrusion or the protrusion and the peak have a groove cut out across them. (6) The scope of the claim for utility model registration, characterized in that the ridges or the ridges and the protrusions at the intermediate portions of the ridges located at both ends are provided with grooves cut out across the ridges. The bearing described in paragraph 4 or 5. (7) The groove portion is discontinuous in the axial direction of the inner peripheral portion, and is arranged with a phase difference from the groove portion formed on the adjacent protrusion or protrusion and peak portion. A bearing according to claim 5 or 6 of the utility model registration claim.