JP2992716B2 - Ball bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball bearing used under conditions of high temperature and large load, such as a roll supporting bearing for a hot dip galvanizing tank.

[0002]

2. Description of the Related Art Conventionally, a hot-dip galvanizing tank has a bearing of 45 pieces.
Since the bearing is used in the molten zinc at 0 to 550 ° C., a sliding bearing has been the mainstream, but recently, an attempt has been made to use a rolling bearing in place of the sliding bearing.

[0003]

Incidentally, the bearing of the hot-dip galvanizing tank requires a large load capacity. Rolling bearings generally have a small load capacity and can receive only light loads, so it is necessary to provide the same type in parallel.
The mounting space for the bearing increases.

[0004] Among the rolling bearings, the roller bearings include:
Although the load capacity is larger than that of the ball bearing, there is a problem that the radial load is concentrated on the edge of the roller and chipping of the edge occurs, which is not preferable in practical use.

[0005] Further, since the support shaft extends in the plating bath due to high temperature, the bearing needs a structure for releasing the expansion and contraction of the support shaft. In a ball bearing, at least one raceway has a raceway surface that is flat along the width direction so that one raceway can be displaced in the axial direction with respect to the other raceway. In addition, the flat raceway surface and the ball are in one-point contact, and the load capacity is further reduced.

In view of the above problems, an object of the present invention is to provide a ball bearing which has a large load capacity and can escape expansion and contraction of a support shaft due to high temperature.

[0007]

According to the present invention, in order to achieve the above object, balls are arranged alternately in the left and right direction in a width direction in a single raceway groove having a width larger than the diameter of one of the raceways. A ball bearing having a raceway surface formed flat in the width direction was constructed.

[0008]

According to the above construction, a large number of balls are loaded between the wide raceways of the inner and outer races, and the load capacity increases. In addition, since one raceway surface in contact with these balls is flat along the width direction, one raceway can freely move in the axial direction with respect to the ball, so that expansion and contraction of the support shaft can be escaped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to one embodiment shown in FIGS. FIG. 1 is a sectional view of a ball bearing according to one embodiment of the present invention, and FIG. 2 is a developed view showing an arrangement state of the balls.

In these figures, 1 is an outer ring, 2 is an inner ring, and 3 is a ball, all of which are made of ceramics mainly containing silicon nitride or the like. The inner ring 2 has a split structure,
A pair of halves 2a and 2b having mutually symmetric shapes are integrally joined. Reference numeral 4 denotes a raceway groove of the outer race 1, and 5 denotes a raceway groove of the inner race 2, and the inner and outer raceway grooves 4, 5 are each formed to be wider than the diameter of the ball 3. Half 2 of inner ring 2
Track grooves 5a and 5b having a radius of curvature larger than the diameter of the ball 3 are formed on the grooves a and 2b, respectively. And
As shown in FIG. 2, a large number of balls 3 are arranged substantially alternately in the right and left sides in the width direction between the track grooves 4 and 5. That is, each ball 3 is supported by one of the raceway grooves 4 of the outer race 1, the raceway grooves 5 a and 5 b of the inner race 2, and four adjacent balls 3 and 3. Of the inner and outer race grooves 4 and 5, the race groove 4 of the outer race 1 has a flat portion 4a in the width direction formed at the center thereof. It can be displaced. For this reason, it is preferable that the axial clearance is at least 1% or more of the ball diameter.

As described above, since the balls 3 are loaded between the inner and outer race grooves 4 and 5 while being alternately displaced to the left and right in the width direction, the number of balls 3 with respect to the race diameter increases, and as a result, Load capacity increases.

Since the raceway groove 4 of the outer race 1 is in contact with the ball 3 at the flat portion 4a, the outer race 1 can be displaced in the axial direction with respect to the ball 3, and the displacement of the support shaft escapes. be able to.

The balls 3 may fall onto the joining surfaces of the halves 2a and 2b of the inner ring 2 due to the circumferential clearance of each ball 3. At this time, the balls 3 are made of ceramics which are more brittle than steel. In order to prevent chipping of the edge of each of the halves 2a and 2b, a slack portion may be formed near the edge.

In the above embodiment, a so-called full ball type ball bearing has been described. However, for example, a retainer 6 as shown in FIG. 3 may be used. As the retainer 6, a punched retainer or a punched retainer having a pocket 7 capable of allowing the ball 3 to move in the axial direction is used.

[0015]

As described above, according to the present invention, a large radial load can be received by a large number of balls, and the load capacity increases. Further, since the inner and outer races can be displaced in the axial direction with respect to each other, even if the support shaft extends due to high temperature, the expansion and contraction can be missed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a ball bearing according to one embodiment of the present invention.

FIG. 2 is a development view showing an arrangement of balls in the embodiment.

FIG. 3 is a plan view of a main part of a cage for a ball bearing according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner ring 3 Ball 4 Outer ring raceway 4a Flat part 5 Inner raceway groove

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Patent Laid-Open No. Sho 50-155551 (JP, A) Jikken Sho 10-15241 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16C 19/08 F16C 33/58

Claims (1)

(57) [Claims] A ball is arranged alternately in the width direction in a single raceway groove wider than its diameter, and the raceway surface of one race is formed flat in the widthwise direction. Ball bearings.