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Description
The SB profile oil seal is a shaft seal composed of a single external metal cage with an internal rubber coating and a primary sealing lip with integrated spring.
Advantages
Good radial rigidity, particularly for large diameters
Good stability when assembled, preventing the bounce-back effect
Sealing for low and high viscosity fluids
Modern primary sealing lip with low radial forces
Applications
Shaft sealing
Motors
Pumps
TransmissionsSpeed The table below indicates the relationships between the linear speed, the rotation speed and the recommended material.
The shaft seals with an additional protective lip are limited to a speed of 8 m/s.
Linear speed calculation:
s (m/s) = [Ø shaft (mm) x speed (rpm) x π] / 60,000Pressure The standard shaft seals are generally used in unpressurised environments, or for pressures between 0.02 and 0.05 MPa maximum.
Higher pressures are acceptable, following testing, for standard NBR or FKM shaft seals used on a shaft diameter less than 30 mm. Refer to the graph below:
For higher pressures, we recommend using high-pressure SCHP - TCHP shaft seals which, because of their specific design (shorter sealing lip, thicker rubber membrane, metal cage closer to the shaft), can support pressures of up to 1.0 MPa with speeds reduced to 0.3 m/s.Temperature The table below indicates the temperature limits, depending on the materials and fluids used.
Suitable materials are:
Shaft hardness will depend on the linear speed (in m/s) and the level of pollution.
Surface roughness
The recommendations below must be considered for the quality of the shaft surface area.
Standard conditions:
The shaft must have a tolerance of h11, in line with standard ISO 286-2
Chamfer and radius
You are strongly advised to install a chamfer on the shaft so as not to alter the primary sealing sealing lip of the shaft seal during assembly. Please refer to the table below.
The SB profile oil seal is a shaft seal composed of a single external metal cage with an internal rubber coating and a primary sealing lip with integrated spring.
Advantages
Good radial rigidity, particularly for large diameters
Good stability when assembled, preventing the bounce-back effect
Sealing for low and high viscosity fluids
Modern primary sealing lip with low radial forces
Applications
Shaft sealing
Motors
Pumps
TransmissionsSpeed The table below indicates the relationships between the linear speed, the rotation speed and the recommended material.
The shaft seals with an additional protective lip are limited to a speed of 8 m/s.
Linear speed calculation:
s (m/s) = [Ø shaft (mm) x speed (rpm) x π] / 60,000Pressure The standard shaft seals are generally used in unpressurised environments, or for pressures between 0.02 and 0.05 MPa maximum.
Higher pressures are acceptable, following testing, for standard NBR or FKM shaft seals used on a shaft diameter less than 30 mm. Refer to the graph below:
For higher pressures, we recommend using high-pressure SCHP - TCHP shaft seals which, because of their specific design (shorter sealing lip, thicker rubber membrane, metal cage closer to the shaft), can support pressures of up to 1.0 MPa with speeds reduced to 0.3 m/s.Temperature The table below indicates the temperature limits, depending on the materials and fluids used.
| Media | Maximum temperature, depending on the materials | |||||||
| ACM | AEM | EPDM | FKM | HNBR | NBR | VMQ | ||
| Mineral oils | Oils for motors | +130°C | +130°C | - | +170°C | +130°C | +100°C | +150°C |
| Oils for gearboxes | +120°C | +130°C | - | +150°C | +110°C | +80°C | +130°C | |
| Oils for hypoid gears | +120°C | +130°C | - | +150°C | +110°C | +80°C | - | |
| ATF oils | +120°C | +130°C | - | +170°C | +130°C | +100°C | - | |
| Hydraulic oils | +120°C | +130°C | +150°C | +130°C | +90°C | - | ||
| Greases | - | +130°C | - | - | +100°C | +90°C | - | |
| Fire-resistant fluids |
HFA group - Emulsion with more than 80% water | - | - | - | - | +70°C | +70°C | +60°C |
| HFB group - Opposite solution (water in oil) | - | - | - | - | +70°C | +70°C | +60°C | |
| HFC group - Polymer aqueous solution | - | - | +60°C | - | +70°C | +70°C | - | |
| HFD group - Water-free synthetic fluids | - | - | - | +150°C | - | - | - | |
| Other fluids | EL + L heating oil | - | - | - | - | +100°C | +90°C | - |
| Air | +150°C | +150°C | +150°C | +200°C | +130°C | +90°C | +200°C | |
| Water | - | - | +150°C | +100°C | +100°C | +90°C | - | |
| Water for washing | - | - | +130°C | +100°C | +100°C | +100°C | - | |
| Temperature range | Min. | -25°C | -40°C | -45°C | -20°C | -30°C | -30°C | -60°C |
| Max. | +150°C | +150°C | +150°C | +200°C | +150°C | +100°C | +200°C | |
The sealing lip of the shaft seal endures a higher temperature due to shaft rotation, and the significant pressure and friction on the mechanical parts. Good lubrication is therefore necessary to allow for a better release of heat and thus limits the temperature rise in the parts subjected to friction.
By definition, the temperature at the edge of the seal is raised when the rotation speed (and thus the linear speed) as well as the shaft diameter increases. The graph below gives an overview of the increase in temperature (in °C) at the point of contact on the sealing lip.
Fluids
Mineral oils
In general, this type of oil has few additives and is therefore perfectly suitable for all of the rubbers used for the rotary shaft seals. The following oils are suitable for rotating applications:
Tolerance for the inside diameter of the seal (Ød)
Free and without constraint, the inside diameter of the sealing lip is always smaller than the diameter of the shaft. The pre-tightening or interference denotes the difference between these two values. Depending on the shaft diameter, the diameter of the sealing lip is generally considered to be less, between 0.8 and 3.5 mm.
Shaft materialBy definition, the temperature at the edge of the seal is raised when the rotation speed (and thus the linear speed) as well as the shaft diameter increases. The graph below gives an overview of the increase in temperature (in °C) at the point of contact on the sealing lip.
Fluids
Mineral oils
In general, this type of oil has few additives and is therefore perfectly suitable for all of the rubbers used for the rotary shaft seals. The following oils are suitable for rotating applications:- motor oils
- gearbox oils
- hypoid oils
- ATF oils for automatic gearboxes
- transmission oils
- brake fluids
- fluids for automatic gearboxes
- fluids for suspensions
- fluids for steering systems
- fluids for hydraulic transmissions
SEAL DESIGN
Tolerance for the outside diameter of the seal (ØD)
The table below indicates the pre-tightening for shaft seals on the housing diameter according to standard ISO 6194-1.| Bore diameter ØD1 (mm) |
Tolerances on the outside diameter ØD of the ring | Roundness tolerance | |||
| Apparent metal cage | Rubber coating | Coating with grooves | Apparent metal cage | Rubber coating | |
| ØD1 ≤ 50.0 | +0.10 / +0.20 | +0.15 / +0.30 | +0.20 / +0.40 | 0.18 | 0.25 |
| 50.0 < ØD1 ≤ 80.0 | +0.13 / +0.23 | +0.20 / +0.35 | +0.25 / +0.45 | 0.25 | 0.35 |
| 80.0 < ØD1 ≤ 120.0 | +0.15 / +0.25 | +0.20 / +0.35 | +0.25 / +0.45 | 0.30 | 0.50 |
| 120.0 < ØD1 ≤ 180.0 | +0.18 / +0.28 | +0.25 / +0.45 | +0.30 / +0.55 | 0.40 | 0.65 |
| 180.0 < ØD1 ≤ 300.0 | +0.20 / +0.30 | +0.25 / +0.45 | +0.30 / +0.55 | 0.25% of ØD | 0.80 |
| 300.0 < ØD1 ≤ 500.0 | +0.23 / +0.35 | +0.30 / +0.55 | +0.35 / +0.65 | 0.25% of ØD | 1.00 |
| 500.0 < ØD1 ≤ 630.0 | +0.23 / +0.35 | +0.35 / +0.65 | +0.40 / +0.75 | - | - |
| 630.0 < ØD1 ≤ 800.0 | +0.28 / +0.43 | +0.40 / +0.75 | +0.45 / +0.85 | - | - |
SHAFT DESIGN
Suitable materials are:
- ordinary C35 and C45 steels used in mechanical construction
- 1.4300 and 1.4112 stainless steels for sealing water
- sprayed carbide coatings
- graphite
- malleable cast iron
- materials with a CVD and PVD coating
- chrome coatings solidified through non-uniform wear
- plastic materials resulting from low thermal conductivity, which can lead to a disturbance in the transport of heat, an increase in temperature in friction areas with the shaft seal, as well as a potential softening
Shaft hardness will depend on the linear speed (in m/s) and the level of pollution.
| Rotation speed | Hardness in HRC |
|---|---|
| s ≤ 4.0 m/s | 45 HRC |
| 4.0 < s ≤ 10.0 m/s | 55 HRC |
| s > 10.0 m/s | 60 HRC |
The recommendations below must be considered for the quality of the shaft surface area.
Standard conditions:
- Ra = 0.2 to 0.8 µm and 0.1 for demanding applications
- Rz = 1.0 to 4.0 µm
- Rmax ≤ 6.3 µm
- Ra = 0.2 to 0.4 µm and 0.1 for demanding applications
- Rz = 1.0 to 3.0 µm
- Rmax ≤ 6.3 µm
The shaft must have a tolerance of h11, in line with standard ISO 286-2
| Shaft diameter Ød1 (mm) |
Tolerance h11 (mm) |
|---|---|
| Ød1 ≤ 3.0 | -0.060 / 0 |
| 3.0 < Ød1 ≤ 6.0 | -0.075 / 0 |
| 6.0 < Ød1 ≤ 10.0 | -0.090 / 0 |
| 10.0 < Ød1 ≤ 18.0 | -0.110 / 0 |
| 18.0 < Ød1 ≤ 30.0 | -0.130 / 0 |
| 30.0 < Ød1 ≤ 50.0 | -0.160 / 0 |
| 50.0 < Ød1 ≤ 80.0 | -0.190 / 0 |
| 80.0 < Ød1 ≤ 120.0 | -0.220 / 0 |
| 120.0 < Ød1 ≤ 180.0 | -0.250 / 0 |
| 180.0 < Ød1 ≤ 250.0 | -0.290 / 0 |
| 250.0 < Ød1 ≤ 315.0 | -0.320 / 0 |
| 315.0 < Ød1 ≤ 400.0 | -0.360 / 0 |
| 400.0 < Ød1 ≤ 500.0 | -0.400 / 0 |
You are strongly advised to install a chamfer on the shaft so as not to alter the primary sealing sealing lip of the shaft seal during assembly. Please refer to the table below.
| Shaft diameter Ød1 (mm) |
Chamfer diameter Ød3 (mm) |
Radius R (mm) |
|---|---|---|
| Ød1 ≤ 10.0 | Ød1 - 1.50 | 2.00 |
| 10.0 < Ød1 ≤ 20.0 | Ød1 - 2.00 | 2.00 |
| 20.0 < Ød1 ≤ 30.0 | Ød1 - 2.50 | 3.00 |
| 30.0 < Ød1 ≤ 40.0 | Ød1 - 3.00 | 3.00 |
| 40.0 < Ød1 ≤ 50.0 | Ød1 - 3.50 | 4.00 |
| 50.0 < Ød1 ≤ 70.0 | Ød1 - 4.00 | 4.00 |
| 70.0 < Ød1 ≤ 95.0 | Ød1 - 4.50 | 5.00 |
| 95.0 < Ød1 ≤ 130.0 | Ød1 - 5.50 | 6.00 |
| 130.0 < Ød1 ≤ 240.0 | Ød1 - 7.00 | 8.00 |
| 240.0 < Ød1 ≤ 500.0 | Ød1 - 11.00 | 12.00 |