Designing of glasses and caps of bearings, Designing of glasses...

Designing cups and bearing caps

Glass Construction

Fig. 4.57

The glasses are usually made of cast iron СЧ15, СЧ18 or from low-carbon steels of the type St3, Ст5.

The thickness of the wall b is taken as a function of the diameter of the bearing bore O.

Flange thickness

The height of the thrust bead/is coordinated with the size of the bevel of the outer ring of the bearing and the possibility of its removal by a screw puller (Figure 4.39).

The diameter (I and the number of bolt holes for fixing the cup to the body n are assigned depending on the diameter of the bearing bore O.

To ensure that the ends of the flange of the beaker and the body are mated along the plane, a groove is made on the outer cylindrical surface of the cup in front of the flange end. The groove profile on the outer surface of the glass and the dimensions of its elements are given in Table. P. 173.

The same grooves are carried out in front of the beads of the cup, but the ends of which are fitted with outer bearing rings.

In the glasses, the bearings of the fixing support of the worm shaft (Figure 4.56) and the shaft bearings of the bevel gear (Figure 4.53.4.55) are usually placed.

The bezels for the bevel gear shaft bearings are moved during assembly to adjust the axial position of the bevel gear. In this case, the cup is placed in the body

Other glasses after they are installed in the body remain stationary. Then

apply landing

Designing bearing caps

The bearing caps are designed to fix the bearing in the housing.

Distinguish the lids that are tucked and embedded.

Bearing caps, screwable

The cover caps are standardized.

End caps with a hole for the lip seal are standardized in accordance with GOST 18512-73 (Table P.290, Figure 4.58), and blind end covers - GOST 18511-73 (Table A.291, Figure 4.59).

If there are no contraindications (for example, the standard lid can not be used when using the glasses because of the insufficient flange diameter), then they should be used in the design. 11If necessary, the cover structure must be corrected.

When designing non-standard covers, it is necessary to pay attention to the following. The shape of the cover depends on the design of the shaft support. Most often, the end of the shaft does not protrude beyond the bearing, so in this case the outer surface of the cover is made flat (Figure 4.59, type 2).

If the shaft end extends beyond the bearing, then the cover is made in type 3 (figure 4.59).

Fig. 4.58

Fig. 4.59

The lid is based on the flange's end, therefore, rigid requirements are imposed on the transition from the end surface to the cylindrical surface. In standard covers (Figure 4.58.4.59), this transition is assigned the limiting value of the transition radius r. For small-scale and individual production on a cylindrical centering surface, a groove with a width L is made in front of the flange face. The dimensions and shape of the groove are shown in Table. P.173.

Determining when designing the cover is the diameter of the hole in the bearing housing.

Below are recommendations for choosing the thickness of flange b, diameter c! and the number of 2 screws fixing the cover to the body, depending on O.

Fig. 4.60

Fig. 4.61

Support surfaces for the heads of the fastening bolts or nuts must be treated more often. Process or directly those places on which the heads of the screws rest (Figures 4.58, 4.59, 4.61), or the entire belt at the end in the area of ​​the screw heads location (Figure 4.60).

From the point of view of precision and manufacturability, turning is preferable (figure 4.60) than machining of bearing surfaces on a drilling machine.

When installing in the bearing cover of the lip seal, there are 2-3 holes (3-4) mm for pushing out the worn out cuff (Figure 4.61).

Fig. 4.62

With a small interaxial distance, the flanges of the two bearing caps can overlap each other. In this case, at both covers the flanges are cut off, leaving a gap (1-2) mm between the slices (Figure 4.62).

Bearing caps

In Fig. 4.63 shows the basic structure of the embedded covers: in Fig. 4.63, a, b - the deaf; in Fig. 4.63, c - with a hole for the output end of the shaft; in Fig. 4.63, g - with threaded hole for pressure screw.

Folding caps are widely used in gears having a plane of connector of the body along the axes of the shafts. These covers do not require attaching threaded parts to the body. They are held by an annular ledge, for which a groove is machined in the body. In order to ensure that the ends of the lid of the lid and the groove of the body are mated along the plane, a groove with a width L is formed in front of the end of the lid on the outer cylindrical surface of the lid. Dimensions of the groove on the diameter O are taken as tab. P. 173.

The outer diameter of the cover is made with such deviations, in which, in conjunction with the housing, the lid forms a very small gap preventing oil from escaping from the housing. The thickness of the wall 8 is taken as a function of the diameter of the bearing bore O (see Section 4.5.2.1).

Cover element changes:

Sometimes the end of the lid, contacting with the bearing, does not coincide with the end of the protrusion (Figure 4.63, b). That the external cylindrical surface of this section does not violate the accuracy of the centering of the lid, all the diameter is somewhat reduced.

Usually, the covers are made of cast iron. However, in order to increase the strength of the thread, the lid with a threaded hole under the pressure screw (Figure 4.63, d) is made of steel.

Fig. 4.63

thematic pictures