JPS628433Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a bearing for a tension pulley used, for example, in an automobile belt transmission mechanism.

Generally, in order to reduce the weight of this type of tension pulley, for example, as shown in FIG. They are butted against each other and joined together with rivets 2, etc., and the bearing 3 is fitted and fixed to the inner cylinder part. However, since both the inner and outer rings of the bearing 3 are made of bearing steel, there is a limit to how much weight can be reduced.

On the other hand, in modern automobiles, there is a strong demand for lighter parts in order to promote energy saving, and the level shown in the first diagram is not satisfactory. Moreover, the weight of the tension pulley as a whole, especially its rotating parts, is large, which means that the rotational resistance during rotation is correspondingly large, resulting in large torque losses, and the use of expensive bearing steel reduces costs. The downside is that it is expensive.

This idea is even lighter than the one in Figure 1,
The purpose of the present invention is to provide a tension pulley bearing that is inexpensive and fully meets the demand for energy saving.

To explain the embodiments, Fig. 2, Fig. 3,
and tension pulley 1 as shown in Figure 4.
0 is collar 1 for hanging the belt and guiding the belt.
1 by bending the outer peripheral end outward.
, an inner cylindrical part 14 having a flange 13 formed by bending the end inward to fit a bearing, and a flat part 15 that connects the inner and outer cylindrical parts at the other end. It consists of a pair of steel plate pulley substrates 16 which are U-shaped press-molded integral rings, and are integrated by symmetrically abutting the flat portions 15 of the substrates 16. In the case of the illustrated embodiment, the means for integrating the two planar parts 15 is to punch a suitable number of circumferential parts of the two overlapping planar parts 15 using a punch or the like (not shown), as shown in FIG. The punched portion 15a is punched out so as to protrude to the left in FIG. Although the two plates are fixedly joined together, other suitable methods such as riveting, spot welding, etc. can be used as the means.

Inner cylinder part 1 of such tension pulley 10
4, the bearing 20 is fitted and fixed to the outer ring 21 of the bearing 20.
The raceway surface 23 of the rolling element 22 is formed on the inner surface,
It is constituted by two annular elements 24 and 25 made of steel plates, which have been hardened to a predetermined hardness by, for example, carburizing and quenching, and subjected to required processing.

One steel plate annular element 24 has a rolling element raceway surface 2
The other annular element 25 made of a steel plate has a short cylindrical part 24b continuous to the large diameter side of the curved part 24a for forming the curved part 24a, and a flange part 24c extending radially inward from the curved part 24a. , a long cylindrical part 25b extending from the large diameter side of the curved part 25a for forming the rolling element raceway surface 23, and a collar part 25c extending radially inward from the curved part 25a, the cylindrical part 25b is configured to have a longer length than the cylindrical portion 24b, and when the outer ring 21 is fitted to the inner cylindrical portions 14 of the pair of pulley boards 16, the longer cylindrical portion 25b is press-fitted and fixed.

With respect to the radius of curvature R of the inner surface of the bent part between each inner cylinder part 14 of the pair of pulley base plates 16 and the collar part 13 extending on the inner diameter side thereof, the two steel plate annular elements 24 forming the outer ring 21, 25 curvature parts 24a, 25a
When the bearing 20 is assembled to the tension pulley 10 with a large radius of curvature r on the outer surface of The flange 13 is configured so that the bearing is positioned by always coming into contact with the outer end surface, that is, the outer end surface of the flange 24c, 25c.
A sealing member 26 for sealing the bearing is compressed and held between and 24c and 25c.

Reference numeral 27 denotes an inner ring, which is made of a sintered alloy and hardened by heat treatment in the embodiment, but may be made of other materials such as bearing steel, tool steel, etc.

It goes without saying that the steel plate pulley substrate 16 and the steel plate annular elements 24 and 25 are made of thin steel plates as thin as possible without impairing the strength of the pulley and bearing.

As described above, in this invention, the outer ring of the bearing, which is fitted and fixed to the inner cylinder of the tension pulley, is constructed of two annular elements made of steel plates, which are as thin as possible without sacrificing their strength. Therefore, the element can be formed very easily by press molding, etc., and its weight is significantly reduced compared to the outer ring of a conventional tension pulley bearing, and the tension pulley assembly itself can be easily formed. This greatly contributes to reducing the weight of the tension pulley, fully meeting the demand for energy saving, and at the same time reducing the inertial weight of the rotating part of the tension pulley, reducing rotational resistance and torque loss. In addition, since the outer ring is manufactured by press forming using a thin steel plate as described above, the cost can be significantly reduced.

This invention also has the advantage that the length of the cylindrical part of one steel plate annular element is longer than that of the other, so that when assembling it to the tension pulley, the longer cylindrical part is The inner cylindrical parts of the pair of pulley boards are guided to improve their assembly accuracy, and the abutting parts of the inner cylindrical parts of the pair of pulley boards are closed at their inner diameters, so that the grease filled in the bearing is released from the abutting parts. Completely prevent leakage.

In addition, the radius of curvature of the outer surface of the curved part that connects the cylindrical part and the flange of the two steel annular elements is determined from the radius of curvature of the inner surface of the bent part that connects the inner cylindrical part and the flange of the pair of pulley boards. When the bearing is assembled, a gap will be created between the outer surface of the curved portion and the inner surface of the bent portion, and the axial end surface of the curved portion of the steel annular element will definitely come into contact with the inner surface of the flange of the pulley board. In this case, positioning when press-fitting the outer ring can be performed with high precision, and variations in the bearing clearance and clamping pressure on the sealing member can be kept constant.

When a sealing member is held under pressure between the flange of the inner cylinder of the pulley board and the flange of the steel annular element, seal both the inner and outer rings and the pulley board and outer ring at the same time. obtain.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the conventional one, Fig. 2 is a longitudinal sectional view of an embodiment of this invention, Fig. 3 is a partial side view, and Fig. 4 is a sectional view taken along the - line in Fig. 3. It is. DESCRIPTION OF SYMBOLS 10... Tension pulley, 12... Outer cylinder part, 13... Collar part, 14... Inner cylinder part, 15... Plane part, 16... Pulley board, 20... Bearing, 2
1... Outer ring, 22... Rolling element, 23... Raceway surface,
24, 25...Steel plate annular element, 24a, 25a
...Curvature part, 24b, 25b...Cylindrical part, 24
c, 25c... flange, 26... seal member.

Claims (1)

[Claims for Utility Model Registration] (1) An outer cylinder part on which the belt is stretched, an inner cylinder part in which a double-row ball bearing is fitted, and the outer cylinder part and the inner cylinder part are continuous in the radial direction at one end thereof. In a bearing that is fitted to a tension pulley that is integrated with a pair of steel plate pulley substrates made up of an integrally molded ring body having a U-shaped cross section and an annular flat portion, the flat portions of which are butted together, the outer periphery is the pulley substrate. a cylindrical part, which is press-fitted and fixed to the inner cylindrical part of the pulley base plate, and has an outer ring that is press-fitted and fixed to the inner cylindrical part of the pulley base plate, and has a raceway surface for the rolling elements formed on the inner surface, and is further hardened and processed to a predetermined hardness; Consisting of two steel plate annular elements each having a curved part continuous to one end of the cylindrical part and extending radially inward from the cylindrical part, and the cylindrical part of one annular element is connected to the other end. The length in the axial direction is longer than that of the cylindrical portion of the element, and the elongated cylindrical portion is press-fitted and fixed to both inner cylindrical portions of the pair of pulley substrates. Bearing for tension pulley. (2) In order to fit and secure the two steel plate annular elements, a flange is formed at the end of the inner cylindrical part of the pair of pulley base plates so as to abut against the axially outer end surface of the curved part. The tension pulley according to claim 1, wherein the radius of curvature of the outer surface of the curved portion of the two steel plate annular elements is made larger than the radius of curvature of the inner surface of the bent portion between the two steel plate annular elements. Bearings for (3) Between the inner surface of the flange formed on the inner cylindrical portion of the pulley board and the outer end surface of the curved portion of the annular steel plate element,
Utility model registration claim 1 or 2 for holding a sealing member for sealing a bearing
Bearing for tension pulley as described in section.