Vibration Isolation Systems

CFM Air Springs, with low natural frequencies (0.6Hz to 2.5Hz), are predominantly used for high-quality Active support of dynamic test rigs, as well as Passive support of sensitive plants, machines and measuring equipment.

Air Springs have been one of our core products for over 30 years. We continue to invest in R&D to ensure improvements are made to the Air Springs and corresponding Level Control Systems, which is why, under normal operating conditions, the lifespan of a CFM Air Spring is over 20 years.

The Air Springs have integrated capacity reservoirs with a pneumatic activation option. The piston is made of steel and cover plate of aluminum. The belted rubber ‘bellows’ are manufactured from high-quality elastomer materials with a vulcanized wire belt, thus exhibiting good vertical and lateral characteristics.

CFM Air Springs have a number of advantages over conventional air springs, including:

• With T-Shaped foundations, benching/housing for the springs is not required
• Additional capacity is integrated thus considerably less space required.

All our CFM Air Springs are designed for specific applications in mind – should a series not be suitable for your application then a bespoke solution can be offered.

CFM steel spring isolators, with integrated viscous dampers, are predominantly used to support machinery and plant whose excitation frequency exceeds approx. 3Hz or which cause impulse excitation; Viscous dampers are particularly relevant to the latter application.

The natural frequencies of our of steel spring isolator series range from 1.8Hz to 6Hz .We manufacture four standard series of steep spring isolators:

• P Series
• UPM Series
• UbPI Series
• SSI Series

All CFM steel spring isolator series are delivered primed and varnished with a two-component lacquer. There is an option for all steel casings to be galvanized or spray-galvanized. Dirt and dust guards are also available. The spiral springs are powder coated, and also coated with cataphoritic dip primer for corrosion protection.

Aside from the standard series, we also manufacture isolators and dampers to suit bespoke applications. The CFM in-house test lab is able to verify these developed products and conduct fatigue testing.

Range of Application include:

• Test Rig Support with high frequency excitation
• Pressing and Punching machines with press loads 500KN to 20MN
• Turbines
• Diesel Generators and Transformers
• Test Rigs for engines, gear units and components
• Pumps and Ventilators
• Chassis roller dynos
• Air Separators
• Shaker Tables
• Earthquake Simulators

Level Controls are required when air springs are employed within an air spring system – they allow for the adjustment of the resting position of the machine or test rig.

There are four standard series of CFM Level Control Unit, from the simple mechanical solution MC300-S to the active position control with microprocessor µC 300 – all are 3-point control systems:

MC 300-S

The MC300 is a mechanical pneumatic level control unit for applications which do not require external monitoring:

• 3-point control system with maintenance and control unit
• control accuracy +- 0.1mm

LC300/302

Electro-pneumatic level control system offering external equipment monitoring:

• level position of all 3 systems
• inlet pressures
• raising/lowering using key switches on control unit
• switching natural frequency of air spring suspension on control unit (LC302 only)
• control accuracy +- 0.1mm

EC 300

Electro-pneumatic level control unit with analogue position encoders and electric control valves, external monitoring. Control accuracy +- 0.05mm

µC 300

Electro-pneumatic active position control system with microprocessor and controller. This system is used to avoid resonance step-ups and minimise time for vibration – this significantly reduces oscillation damping time.

Concrete foundations and base plates positioned on air/steel springs are ideally suited to guarantee vibration isolation of machinery or test rigs. We offer a complete design service in this regards, with complimentary construction and installation services upon request.

The Seismic Block serves as the rigid base for the machine, and also as an inert mass. The foundation usually consists of a reinforced concrete structure with a cross-sectional shape and block adapted to suit the individual application – blocks typically range between 20 to 2000 tonnes.

A cast iron bedplate can be individually designed, manufactured and installed to suit any application – T-Slots or drilled and tapped surface hole grids are machined to accommodate (clamp down) the machinery or test rig.

Vibration isolation lab and working tables (series ISO-LT) feature low-frequency, self-leveling table tops. They are predominately employed for passive isolation of sensitive equipment and measuring instruments.

Our modular lab tables ISO-LT enable flexible and ergonomic design of the workplace. There are two different table tops available to suit a variety of applications: hard stone or cast iron.

The vibration isolation tables are supported by at least four membrane air springs series CFM-MAS, which are integrated in the table columns. The isolation system is fitted with a 3-point leveling system that guarantees an accuracy of ±0.02 mm.

The table features an integrated control and maintenance unit to supply the control system. The tuning frequency is approx. 2.3 Hz. The table can be supplied with a natural frequency up to 1.5 Hz on request.

Technical description:

• The steel base frame is extremely stiff with an attractive, modular design. The surface is painted or powder-coated according to customer request.
• Table feet with integrated membrane air springs from the MAS series with vertical natural frequency from 2.3 Hz to 1.5 Hz are available for order. The membrane air springs are fitted with adjustable damping; the legs also feature built-in leveling feet.
• Highly accurate 3-point level control system with maintenance and control unit. The additional active level control system CFM-MC 300 is available on request; Level accuracy +/- 0.02mm.
• Table top in granite or gray cast iron; the surfaces are polished or precision machined. Optional grid of tapped holes available on request.
• Matching armrests, PC, keyboard and monitor mounts are available on request.
• Rollers for easy movement of the table are available as an option.

Surface precision:

Granite: polished DIN 876/I

Cast iron: milled DIN 876/III

Table sizes:

All tables are available in the standard heights of 760 mm and 900 mm. Other heights are available on request and are made-to-measure in-house.