Special Oil Seals (Perfect Seal, Helix Seal, Super Helix Seal, etc.)

How to choose Oil Seals

Points to check when selecting, with the values for this product (Special Oil Seals (Perfect Seal, Helix Seal, Super Helix Seal, etc.)).

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

   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 hydrodynamic ribs on the air-side surface of the lip improve sealing performance and durability. The series includes the Perfect Seal for both-direction rotation and the Helix series for one-direction rotation.

FAQ

Q. How should the Special Oil Seals (Perfect Seal, Helix Seal, Super Helix Seal) be selected based on rotation direction?

A. The Perfect Seal is compatible with both-direction rotation. The Helix Seal is compatible with one-direction rotation. The Super Helix Seal is a design that maintains durability with two-stage ribs.

Q. What applications are special oil seals used for?

A. They are used in applications such as reducer input shafts, engine crankshafts, oil pumps, and differential sides.

Q. How are the sealing performance and durability of special oil seals improved?

A. Sealing performance and durability are improved by the hydrodynamic ribs on the air-side surface of the lip. The hydrodynamic ribs enhance the pumping action.

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/