GB/T 13871.1-2022Rotary shaft lip-type seals incorporating elastomeric sealing elements - Part 1: Dimensions and tolerances (English PDF)

5.1 Seal outside-diameter construction

Figure 1 shows four basic types of outside-diameter construction of the seal.

Figure 1 - Four basic types of outside-diameter construction

5.2 Seal construction without and with protection lip

See Figure 2 for two types of seal construction without and with protection lip.

See Figure 3 for the schematic diagram of the common construction of air-side surface of the sealing lip.

Figure 3 - Construction of air-side surface of the sealing lip

5.4 Construction of the rubber-covered metal-cased seal

See Figure 4 for the schematic diagram of the common construction of the rubber-covered metal-cased seal.

5.5 Construction code of the seal

The various constructions shown in Figure 1, Figure 2, and Figure 3 can be combined and applied with each other, and the construction codes could be as follows:

-- Single letters W, Z and B (see Figure 1) indicate the seal construction without protection lip and without wave-profile;

-- Two-letters FB, FW and FZ, starting with F, indicate the seal construction with protection lip and without wave-profile; F indicates the existing of a protection lip, and the second letter indicates the outside-diameter construction (see Figure 1);

-- Two-letters WL, ZL, BL, WR, ZR and BR, not beginning with F, indicate the seal construction without protection lip and with wave-profile; the first letter indicates the outside-diameter construction (see Figure 1), and the second letter indicates the direction of the wave-profile (see Figure 3);

-- Three-letters FBL, FWL, FZL, FBR, FWR and FZR indicate the seal construction with protection lip and with wave-profile; the first letter F indicates the existing of the protection lip, the second letter indicates the outside-diameter construction (see Figure 1), and the third letter indicates the direction of the wave-profile (see

Figure 3).

The design of the sealing lip is mainly carried out by the manufacturer (to ensure sealing); it can also be agreed between the manufacturer and the buyer.

Note: The constructions shown are only representative examples of the basic types. For the specific design details, refer to GB/T 9877-2008.

6.1 Operating pressure

Seals are normally used with atmospheric pressure on the air side, and sealing fluids at pressures of 0 kPa ~ 50 kPa above atmospheric pressure. The user shall consult the seal manufacturer regarding use at other pressures.

6.2 Dimension series

The assembling diagram of the seal is shown in Figure 5 and the dimension series are given in Table 1.

7.2 Diametral tolerance

The shaft shall have a diametral tolerance not greater than h11 as specified in GB/T 1800.2-2020.

7.3 Surface roughness and hardness

7.3.1 Surface roughness

The seal contact surface of a ground shaft shall be finished to a surface roughness, measured in the axial direction of Ra 0.2 um ~ Ra 0.8 um, or Rz 0.8 um ~ Rz 3.2 um, as specified in GB/T 1031-2009.

If the surface roughness value of the shaft does not fall within the limits given in this document, it shall be determined between the user and the seal manufacturer.

7.3.2 Surface hardness

The surface hardness of the shaft shall be a minimum of HRC30. If the surface hardness of the shaft is less than HRC30, it shall be subject to agreement between the user and the seal manufacturer.

8.1 Dimensions

8.1.1 Where the housing is a rigid fully machined ferrous part, the housing bore shall

conform to 8.2 and 8.3.

8.1.2 The housing bore shall be provided with a lead-in chamfer, free from burrs, as

shown in Figure 7 and specified in Table 6.