Solution For Sealing & Bearing Applications In Aerospace Industry

Application Examples of Aerospace Industry

Determining the proper solution for a sealing and bearing application requires expertise in many areas, such as sealing technology, fluid dynamics and material science.

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Air Control Linkage - Thermoplastic Bearings

The customer wanted to replace an existing bronze bushing with a longer-life, maintenance-free product.

The HiMod® bearing extended the life and reliability of the equipment and increased the length of time between preventive maintenance procedures.

The HiMod® bearing performed exceptionally well and the life cycle of the equipment was substantially improved.

Maintenance costs have been substantially reduced and there has been an increase in product safety and reliability.

Service Conditions

+177°C / +350°F
Oscillating movements
Internally sealed
High vibration

HiMod® - High Performance Thermoplastic Bearings

High Temperature Seal For Flexible Bleed Air Duct

Air Dust
The customer wanted to replace the existing silicone O-Ring, which failed under compression set at high temperature. The new design had to maintain current rod and bore diameters and groove width.

In addition, the new design had to pass a pressure pulse test of 300,000 cycles, with stringent leakage requirements.

Standard Turcon® Variseal® M2 with a Turcon® T11 jacket and heavy load V-spring

The specified seal passed the pressure cycle test, met all of the performance requirements, extended the operational life of the entire hot bleed air system, and reduced the required maintenance.

Service Conditions
0.4 to 1.2 MPa / 60 to 170 psi
-54°C to +260°C / -65°F to +500°F
Slow reciprocating / Static
Hot Engine Bleed Air

Turcon® Variseal® M2 (V-spring-energized rod seal)

PCTFE Face Seal For Cryogenic Paint Blaster

Units fitted with O-Rings experienced excessive leakage at temperatures below -90°C / -130°F. With desired operating temperatures as low as -253°C / -423°F, a new seal design was needed.

Custom Turcon® Variseal® WF with a Polymonochlorotrifluoroethylene (PCTFE) jacket and a heavy-load Slantcoil® spring

For temperatures this low, stability of jacket material is crucial. The PCTFE jacket in this design offered the superior stability required, and the heavy spring provided the load necessary to create and maintain a positive seal.

Service Conditions
0.14 ~ 2.8 MPa / 20 ~ 400 psi
-253°C / -423°F
Nitrogen, CO2 pellets

Turcon® Variseal® FW (Slantcoil®-energized flange seal)

PTFE Face Seal For High-Pressure Fuel Pump

Compression setting and degradation of the previous 80 durometer O-Rings caused the customer to search for a replacement seal design.

The new seal had to fit into the existing gland, provide longer life and better reliability.

Custom-extended heel Turcon® Variseal® HF with a Turcon® T01 jacket and heavy-load helical spring

The specified seal fitted the existing gland and provided leak-tight performance that exceeded the customer’s specifications.

Premature failure was eliminated and maintenance costs were significantly reduced.

Service Conditions
35 to 55 MPa / 5000 to 8000 psi
-54°C to +260°C / -70°F to +100°F
Jet fuel

Turcon® Variseal® WF(Slantcoil® spring-energized face seal)

PTFE Seal For Aircraft APU

The task was to design a lightweight shaft seal with reduced space requirements to replace the mechanical face seal that was designed into the original aircraft auxiliary power unit (APU.)

A conventional oil seal was first considered by the customer, but it generated too much friction for the application.

Standard Turcon® Varilip® PDR TP1 with a Turcon® T25 sealing element and a Stainless Steel case

The Turcon® Varilip® PDR TP1 brought the running torque down to 0.3 lb in. with much better performance than the elastomeric oil seal and was lighter and smaller than the mechanical face seal.

Service Conditions
.07 MPa / 10 psi
-54°C to +163°C / -65°F to +325°F
6 to 13 m/s / 1255 to 2620 sfpm
Mil-L-23699 oil

Turcon® Varilip® PDR TP1 Polytetrafluoroethylene (PTFE) shaft sea

Rotor Damper Bearing

Engineering requirements in military aircraft applications are always rigorous. This is especially so when high-speed aircraft pass through different atmospheric conditions in a matter of minutes or remain in them for very long periods of time.

Rotor damper main bearings in the U.S. Navy’s Seahawk helicopters suffered service problems.

Crucial parts were plagued by premature wear, leading to frequent downtime. This resulted in critical equipment being out of service. Short product life was traced to the use of some bearing components made from beryllium copper.

The engineering design team took an innovative approach. To reduce friction and wear, some nonferrous metal parts were replaced with HiMod® 924 polymer bearings, and the elimination of metal-to-metal contact was achieved.


HiMod® bearings could better withstand such demanding load and high vibration conditions.

In addition, the bearings offered a better strength-to-weight ratio, excellent abrasion resistance, chemical resistance and vibration dampening properties.

Service Conditions
Atmospheric pressure
-54°C to +148°C / -65°F to +300°F
250 cpm with high vibration
High dynamic stresses

HiMod® High Performance Thermoplastic Bearings

Seal For High Vacuum Quick Disconnect

For this space station application, leakage control was absolutely vital. The vacuum and pressure combined with the temperature range and gland design made this application challenging.

Custom Turcon® Variseal® W2 with a Polymonochlorotrifluoroethylene (PCTFE) jacket and a heavy-load Slantcoil® spring

As difficult as the operating conditions were, the solution was rather simple. The specified seal was a Turcon® Variseal® W2 machined at a 45° angle. With the proper choices of jacket material and spring load this seal provided both the reliability and sealability required for use in the space station.

Service Conditions
10-5 Torr to 3.1 MPa / 450 psi
-87°C to +60°C / -124°F to +140°F
Static / Slow oscillating
Anhydrous ammonia

Turcon® Variseal® W2 (Slantcoil®-energized rod seal)

Smooth-Running PTFE Seals For Airframe Test Rig

A test rig for the C17 transport plane involved numerous hydraulic cylinders mounted between the airframe and support structure. The longest stroke in the cycle occurred during simulation of a 2.5 g downward load on the aircraft wings.

Sealing system stick-slip was contributing to hysteresis in the simulation, which created a need for an alternative sealing solution.

Custom Turcon® Variseal® W with a Turcon® T17 jacket and medium-load Slantcoil® spring

The proposed solution withstood stress testing equivalent to 60,000 flight hours (17,000 missions and 24,000 landings). The C17 simulator hydraulic sealing system met or exceeded all requirements.

Service Conditions
21 to 52 MPa / 3000 to 7500 psi
-54°C to +121°C / -65°F to +250°F
102 to 2032 mm / 4” to 80” stroke
Mil-H-5606, DTE 24


Turcon® Variseal® W (Slantcoil®-energized piston seal

Gearbox Spring-Energized PTFE Shaft Seal

Leather seals that had been the mainstay for years in previous designs within this application were no longer able to handle increasing speeds and performance demands.

The customer required a new seal design that would provide better wear and greatly reduce leakage, friction and downtime.

Standard Turcon® Variseal® CM with a Turcon® T09 jacket and medium-load V-spring


The specified seal met all of the customer’s requirements. It lasted longer and reduced leakage, friction and downtime.

Service Conditions
0 psi
-34°C to +38°C / -30°F to +100°F
340 rpm (bidirectional)
2.3 m/s / 444 sfpm
Mil-G 23837 and dust

Turcon® Variseal® M (V-spring-energized rod seal)
Turcon® Variseal® CM (V-spring-energized canned rotary seal)

Thrust Vectoring Control Linkage

The customer was looking for a dry running bushing to use in a new vectoring device system. As this was a new product development, the customer turned to Trelleborg Sealing Solutions for bearing design assistance.

The design needed to incorporate linear motion with a slow controlled helical rotation.

The design engineers worked with the client to determine the primary operation objectives. As a result, HiMod® was chosen to produce a bushing that would provide outstanding life and reliability.

The HiMod® bushing proved to be superior. The customer reported maintenance-free service with outstanding life and consistent operation over a wide temperature range.

Service Conditions
Dry service
Slow linear actuation with rotational component
+71°C / +160°F
Intermittent usage

HiMod® High Performance Thermoplastic Bearings