JP2524085Y2 - Energized rolling bearing - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a current-carrying rolling bearing which is incorporated in, for example, a steering device for an automobile and is used to rotatably support a metal steering shaft inside a metal steering column. .

[0002]

2. Description of the Related Art A horn switch is provided on a steering wheel portion of a steering apparatus for an automobile, and electrical wiring is performed. The electric wiring is composed of a circuit flowing through a cord or the like insulated from the vehicle body, and an earth circuit flowing through the vehicle body.

On the other hand, a steering shaft supporting the steering wheel at the upper end is rotatably supported inside a steering column supported by a vehicle body via a pair of upper and lower rolling bearings. When the steering shaft and the steering column are made of metal, the rolling bearing forms a part of a ground circuit. However,
When an electric current is applied to the rolling elements constituting the rolling bearing, the rolling surfaces of the rolling elements and the raceway surfaces of the inner and outer rings in contact with the rolling surfaces are electrically corroded. For this reason, the durability of the rolling bearing is impaired.

[0004] For this reason, conventionally, a current-carrying rolling bearing as shown in FIGS. 9 to 12 has been used in a portion where electricity flows, such as a steering device for an automobile. First, the first type shown in FIGS.
In the case of the example, the ring-shaped current-carrying plate 1 having a shape as shown in FIG. 10 is made of a thin metal plate having a small electric resistance such as copper. Then, a plurality of protrusions 4, 4 formed on the outer peripheral edge of the conductive plates 1, 1 are caulked and fixed to locking grooves 3, 3 provided at both ends of the inner peripheral surface of the outer ring 2, as shown in FIG. I do. The plurality of protrusions 5 formed on the inner peripheral edge of each energizing plate 1 are elastically contacted with stepped portions 7 formed on the outer peripheral surface of the inner ring 6, respectively.

[0005] The outer race 2 and the inner race 6 are relatively rotated by the rolling members 9, 9 rotatably provided between the two members 2, 6 while being held by the retainer 8. I do. In this case, most of the current flowing between the outer ring 2 and the inner ring 6 passes through the conductive plates 1 and 1 having a small electric resistance. For this reason, the current flowing through the rolling elements 9 is small, and no electrical corrosion occurs on the rolling surfaces of the rolling elements 9 and the raceway surfaces of the inner and outer rings 6 and 2.

In the case of the second example shown in FIGS.
As shown in FIG. 11, a partially annular wire spring 10 as shown in FIG. 12 is locked in a locking groove 3 on the inner peripheral surface of the outer ring 2. The folded portions 1 formed at both ends of the wire spring 10
1 and 11 are elastically pressed against the inside of the locking groove 12 on the outer peripheral surface of the inner ring 6. In the case of the structure shown in FIGS. 11 to 12, most of the current flowing between the outer ring 2 and the inner ring 6 flows through the wire spring 10 having a small electric resistance. Therefore, electric corrosion does not occur on the rolling surfaces of the rolling elements 9 and the raceways of the inner and outer rings 6 and 2.

[0007]

However, in the case of a conventional energized rolling bearing having the above-described structure, it is desired to improve the rolling as described below. First, FIGS.
In the case of the first example shown in FIG. 0, each energizing plate 1 is caused by a variation in swaging strength that occurs when the protrusions 4, 4 formed on the outer peripheral edge of the energizing plates 1, 1 are caulked and fixed to the outer ring 2. The strength with which the protrusions 5 on the inner peripheral edge of the inner ring 6 are pressed against the steps 7 on the outer peripheral surface of the inner ring 6 is likely to vary. As a result, the conductive plates 1, 1
The electric resistance between the outer ring 2 and the inner ring 2 increases (when the pressing force is small), or the frictional force acting between the protrusions 5 and 5 and the steps 7 and 7 increases. On the other hand, the torque required to rotate the inner ring 6 tends to increase (when the pressing force is large).

In the case of the second example shown in FIGS.
As in the case of the first example, not only does the torque required to rotate the inner ring 6 with respect to the outer ring 2 increase, but also the wire spring 10 may come off. And this wire spring 1
When 0 comes off, the rolling surfaces of the rolling elements 9, 9 and the inner and outer rings 6,
It becomes impossible to prevent the occurrence of electrical corrosion on the raceway surface of No. 2. The current-carrying rolling bearing of the present invention is designed to eliminate any of the above-mentioned disadvantages.

[0009]

According to the present invention, there is provided a current-carrying rolling bearing comprising: an inner ring having an inner raceway on an outer peripheral surface; an outer race having an outer raceway on an inner peripheral surface; It is composed of a plurality of rolling elements movably provided, a synthetic resin retainer for holding the plurality of rolling elements so as to freely roll, and a metal plate fixed to the retainer. The inner peripheral edge is in sliding contact with the outer peripheral surface of the inner race, and the outer peripheral edge of the metal plate is in sliding contact with the inner peripheral surface of the outer race.

[0010]

In the case of the current-carrying rolling bearing of the present invention configured as described above, the inner ring and the outer ring are electrically energized by the metal plate, and most of the current flowing between the outer ring and the inner ring is:
Since the current passes through the metal plate having a small electric resistance, the current flowing through the rolling element is small, and the rolling surface of the rolling element and the raceway surfaces of the inner and outer rings are not electrically corroded. Further, the contact pressure between the inner and outer peripheral edges of the metal plate fixed to the retainer, the outer peripheral surface of the inner race, and the inner peripheral surface of the outer race can be stabilized. Further, the metal plate does not fall off. Therefore, the electric resistance between the inner ring and the outer ring can be reliably reduced over a long period of time without increasing the rotational torque of the energized rolling bearing.

In addition, the relative rotational speed between the cage and the inner ring,
In addition, since the relative rotation speed between the retainer and the outer ring is about half of the relative rotation speed between the inner ring and the outer ring, the relationship between the inner and outer peripheral edges of the metal plate and the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. The sliding speed of the sliding contact portion can be reduced to about half as compared with the conventional structure described above. Therefore, the wear of the sliding contact portion can be reduced.

[0012]

1 to 3 show a first embodiment of the present invention. A plurality of rolling elements 9 are rotatably provided between an inner raceway 14 formed on the outer peripheral surface of the inner race 6 and an outer raceway 15 formed on the inner peripheral surface of the outer race 2. The plurality of rolling elements 9 are rotatably held by a synthetic resin retainer 16.

As shown in FIG. 3, a metal plate 17 made of a material having a low electric resistance such as copper and having a shape as shown in FIG. 2 is inserted into the retainer 16 made of synthetic resin. . Thus, the metal plate 17 is placed on the retainer 16 made of synthetic resin.
Is inserted by holding the metal plate 17 at a predetermined position inside the mold when the cage 16 is injection-molded. The inner peripheral edge of the metal plate 17 thus inserted into the retainer 16 made of synthetic resin is formed on the inner peripheral surface of the locking groove 12 formed on the outer peripheral surface of the inner ring 6. Are in sliding contact with the inner surfaces of the locking grooves 3 formed on the inner peripheral surface of the outer ring 2.

In the case of the current-carrying rolling bearing of the present invention configured as described above, the inner ring 6 and the outer ring 2 are electrically connected to each other by the metal plate 17 having good electrical conductivity. Most of the current flowing between the metal plates 17 flows through the metal plate 17. Therefore, the current flowing through the rolling elements 9 provided between the outer ring 2 and the inner ring 6 becomes small. As a result, no electrical corrosion occurs on the rolling surfaces of the rolling elements 9 and the raceways of the inner and outer rings 6 and 2.

In addition, when the current-carrying rolling bearing is used, the relative rotational speed between the retainer 16 in which the metal plate 17 is inserted and the inner ring 6 and the relative rotational speed between the retainer 16 and the outer ring 2 are determined by the inner ring 6 It is about half of the relative rotation speed with respect to the outer ring 2. Therefore, the sliding speed of the sliding contact portion between the inner and outer peripheral edges of the metal plate 17 and the outer peripheral surface of the inner race 6 and the inner peripheral surface of the outer race 2 can be reduced to about half as compared with the conventional structure described above. Therefore, in the case of the present invention, wear of the sliding contact portion can be reduced by lowering the sliding speed of the sliding contact portion.

Further, in the case of this embodiment, the metal plate 17
Is inserted into the cage 16 at the time of injection molding of the cage 16 made of a synthetic resin, so that the production work of the cage with the metal plate is easy and the production cost is not increased. Also, since the mounting position of the metal plate 17 with respect to the retainer 16 becomes stable,
The inner and outer peripheral edges of the metal plate 17 and the locking grooves 12, 3
The contact pressure with the inner surface is stabilized. For this reason, the electrical resistance of the contact portion between the metal plate 17 and the outer ring 2 or the inner ring 6 does not increase, or significant wear does not occur on the contact portion.

Next, FIGS. 4 to 6 show a second embodiment of the present invention. In the first embodiment described above, the piece-shaped metal plate 17 is used.
Is inserted in a cage 16 made of synthetic resin, whereas in the case of this embodiment, a metal plate 18 made in a closed annular shape as shown in FIG. 5 is used. This metal plate 18 has sliding contact portions 20 and 20 formed at four locations on the circumference of the connecting ring portion 19, and is inserted into a synthetic resin retainer 16 as shown in FIG. As shown, it is incorporated into a rolling bearing together with the cage 16.

As shown in FIG. 4, when the metal plate 18 and the retainer 16 are assembled into a rolling bearing, the inner peripheral edges of the sliding portions 20, 20 are formed on the outer peripheral surface of the inner ring 6. The outer peripheral edge is in sliding contact with the inner surface of the locking groove 12 and the inner surface of the locking groove 3 formed on the inner peripheral surface of the outer race 2. Other configurations and operations are the same as those of the above-described first embodiment.

FIGS. 7 and 8 show third and fourth embodiments of the present invention. In both of these embodiments, the copper current-carrying pieces 21 and 21a, which are metal plates, are fixed to the retainer 8 by rivets 13 to which the metal retainer 8 is assembled. Then, both ends of the conductive pieces 21 and 21a are elastically pressed against the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the inner ring 6. In both of these embodiments, the mounting positions of the conducting pieces 21 and 21a with respect to the holder 16 are stable, as in the first embodiment and the second embodiment described above.
For this reason, the contact pressure of the contact portion between both peripheral edge portions of each of the current-carrying pieces 21 and 21a and the outer ring 2 and the inner ring 6 is stabilized, and the electrical resistance of the contact portion increases, or No significant wear is caused on the surface.

[0020]

[Effects of the Invention] Since the current-carrying rolling bearing of the present invention is constructed and operates as described above, the rotational torque is stable, and the electrolytic corrosion of the rolling surface and the raceway surface can be reliably performed over a long period of time. It is possible to provide a current-carrying rolling bearing which can be prevented. Further, the wear of the sliding contact portion can be reduced, and excellent durability can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a front view of a metal plate used in the first embodiment.

FIG. 3 is a front view of a cage made of a synthetic resin into which a metal plate is inserted.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a front view of a metal plate used in the second embodiment.

FIG. 6 is a front view of a cage made of a synthetic resin into which a metal plate is inserted.

FIG. 7 is a sectional view showing a third embodiment of the present invention.

FIG. 8 is a sectional view showing the fourth embodiment.

FIG. 9 is a sectional view showing a first example of a conventional energized rolling bearing.

FIG. 10 is a front view of a conductive plate used in the first example.

FIG. 11 is a sectional view showing a second example of a conventional energized rolling bearing.

FIG. 12 is a front view of a wire spring used in the second example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Current-carrying plate 2 Outer ring 3 Locking groove 4 Projection 5 Projection 6 Inner ring 7 Stepped portion 8 Cage 9 Rolling element 10 Wire spring 11 Folding portion 12 Locking groove 13 Rivets 14 Inner ring raceway 15 Outer ring raceway 16 Cage 17 Metal plate Reference Signs List 18 metal plate 19 connecting ring part 20 sliding contact part 21, 21a conducting piece

Claims (1)

(57) [Scope of request for utility model registration] An inner race having an inner raceway on an outer peripheral surface, an outer race having an outer raceway on an inner peripheral surface, and a plurality of rolling elements rotatably provided between the inner raceway and the outer raceway. A retainer made of a synthetic resin, which holds a plurality of rolling elements so as to be able to roll freely, is composed of a metal plate fixed to the retainer, and an inner peripheral edge of the metal plate on an outer peripheral surface of the inner ring, A current-carrying rolling bearing wherein an outer peripheral edge of the metal plate is slidably contacted with an inner peripheral surface of the outer ring.