Oil Seals (Standard Types such as MHSA, HMSA, MHSD, HMSD)

Specifications

How to choose Oil Seals

Points to check when selecting, with the values for this product (Oil Seals (Standard Types such as MHSA, HMSA, MHSD, HMSD)).

1. 1. Match shaft diameter and housing bore

   Select shaft diameter d and outer diameter D by nominal dimensions to suit the mating shaft and housing bore. Listed shaft diameters range widely from 6 to 3530 mm. Some standard types are designed assuming shaft tolerance h8 and housing bore tolerance H7/H8. Deviation from fit tolerances can cause leakage or seal dislodgement.

2. 2. Check width fits the installation space

   Confirm that width b fits within the axial installation space. Listed products are 5 to 30 mm. For large types, cross-section width, groove width, and presence of spacers are also part of the dimensional requirements, so verify against the housing groove dimensions.

3. 3. Select lip material suited to fluid and temperature

   Lip material governs oil resistance and heat resistance. Nitrile rubber is a general-purpose material for mineral oils, acrylic and fluororubber suit the high-temperature range, and silicone readily covers low to high temperatures. PTFE lips are suitable for chemicals and high temperatures, and food-hygiene-compliant materials are available for food machinery.

4. 4. Allow margin in operating temperature range

   Confirm that the continuous operating temperature range includes the running oil temperature. Temporary temperature rises, such as at startup, are judged by the short-term maximum temperature (120 °C in one listed example). However, if the normal operating temperature is close to the upper limit, rubber hardening and lip wear will accelerate.

5. 5. Verify shaft surface speed is within limit

   This product: Maximum Peripheral Speed Approx. 10〜20 m/s

   Surface speed is the lip sliding speed calculated from shaft diameter and rotational speed. The listed maximum surface speeds are 5 to 20 m/s, and exceeding them causes lip deterioration from frictional heat. Even at the same rotational speed, surface speed increases with larger shaft diameter, so check this particularly for large-diameter shafts.

6. 6. Confirm maximum sealing pressure limit

   Standard oil seals are intended for low-pressure use. Listed maximum operating pressures vary greatly by type, from 0.03 to 15 MPa, so select a pressure-resistant type for applications with internal pressure. Under pressure the lip is pressed strongly against the shaft, making heat generation more likely.

This guide was written by AI based on the listed products' documents and specification items.

About Oil Seals and all products

Description

The type is determined by a flowchart based on operating conditions: housing material, sealed medium, pressure, peripheral speed, eccentricity, and dust environment. Permissible peripheral speed, permissible pressure, and eccentricity limits are indicated as reference values that vary with shaft diameter and rotational speed.

FAQ

Q. How can I select the type of standard oil seals such as MHSA, HMSA, and MHSD based on operating conditions?

A. The type is determined using a flowchart based on operating conditions such as housing material, sealed medium, pressure, peripheral speed, eccentricity, and dust environment.

Q. What is the maximum peripheral speed of MHS and HMS series oil seals?

A. The maximum peripheral speed is approximately 10 to 20 m/s. Permissible peripheral speed is a reference value that varies with shaft diameter and rotational speed.

Q. How is dust ingress prevented in MHS and HMS series oil seals?

A. Dust ingress is prevented by the auxiliary lip.

Q. What are the recommended surface finish conditions for the shaft and housing of MHS and HMS series oil seals?

A. The housing bore surface roughness is 0.4 to 1.6 μmRa, and the shaft surface roughness is 0.1 to 0.32 μmRa. The recommended shaft hardness is 50 to 60 HRC.

Q. What shaft diameter and housing bore tolerances are MHS and HMS series oil seals designed for?

A. They are designed for shaft diameter h8 and housing bore H7/H8.

Written by AI based on the content of the source documents.

Source documents

• Catalog オイルシール ＆ Oリング
  Found on: https://koyo.jtekt.co.jp/support/catalog-download/