EMCÉ Launches a New Range of Air-operated Motors
08 November 2005
EMCÉ launches a new range of air-operated motors
Machinefabriek EMCÉ BV (subsidiary of Stokvis Holding) launches a new series of air-operated motors for its range of pneumatic winches. The gear motors (LG series) have already been successfully applied to various OAW and MR series winches and they will be applied to all other pneumatic winches in the future as standard.
In the past, piston motors were mainly used for winches with larger capacities and vane motors were used for smaller capacities. The advantages of the gear motors in comparison with piston motors are discussed later in this article.
To elucidate, it does not concern an air-operated motor in combination with a gearbox as some suppliers indicate for their motors, but a fully integrated air operated gear motor.
Stokvis Holding
The gear motors are produced within the Stokvis Holding and are developed in cooperation with a specialist in this field. For the benefit of the production, assembly and the testing of these motors, but also because of the growth of EMCÉ in general, the company was recently expanded by 1200 m2 and it recruited six new staff.
Since the development of the piston motors more than 30 years ago, no appreciable developments have occurred in the field of air-operated motors with capacities above 10 kW as all applications are principally found in a niche market, and certainly because it does not concern a growth market. However, for EMCÉ, a specialist in the field of customer-specific winches, which is growing strongly worldwide in the field of pneumatic winches, especially in the oil and gas sector, there were a number of motivating reasons to develop and produce these motors, namely:
-product improvements (see explanation);
-cost price reduction (see explanation);
-continuity (see explanation);
-life span;
-maintenance cost reduction;
-reliability.
Product (capacity) improvement
The currently available piston motors do not come up to the specified capacity characteristics and certainly not when they are fitted with the components that are needed to be able to use such a motor in a machine.
Using sound mufflers is unavoidable as air expansion means that sound levels way above 115 dB(A) are normal. Moreover, one must be able to control the airflow with a control valve. These components cause a certain amount of back pressure, which causes appreciable capacity reduction in piston motors. The complexity of the internal airways in the piston motor and the rotating distribution valve in combination with these components means that this back pressure is substantially higher than in gear motors. In various tests, EMCÉ has shown that all these counteractions together result in a power loss of more than 30%.
The gear motors have a substantially lower internal back pressure owing to the construction chosen, which includes a number of outlets and therefore a number of sound mufflers to reduce this back pressure even more. However, one can possibly make positive use of this back pressure when one desires a slower winch speed in the downward movement, e.g. when lowering people. It is known that lowering a load helps to drive the motor; it therefore starts working as a compressor (this is also known as the generator working). This can mean that the downward speed can be more than 30% higher than in the lifting movement. EMCÉ gives all its gear motors a universal and adjustable outlet valve to prevent this generator working regardless of the winding direction of the cable on the drum. This direction can be adjusted by the customer, as can the width of this valve. This throttled valve is also known as a "biased" valve.
Conclusion: the capacity improvement that is principally expressed in a higher output speed means that higher speeds are achieved for the EMCÉ winches, even under full loads and at equal operating pressure and air consumption, in comparison with a piston motor.
Cost price reduction
The realised initial cost price reduction means that EMCÉ kills 2 birds with one stone. Namely the reduction of the operational costs of the winches, which is perhaps even more important to the end user than the initial purchase costs. This cost reduction must mainly be sought in the simplicity of the design and the reduction of the number of components used.
As an example, a piston motor according to specifications of ~21 kW (measured by EMCÉ in combination with valve and mufflers as not more than ~15 kW) comprising 80 different parts and a total of 157 components. An EMCÉ gear motor, on the other hand, comprises 30 different parts and a total of 83 components. Both motors excluding the control valve and optional brake comprise a comparable number of parts.
It will therefore be clear that the total costs for spareparts are lower because of this.
The demand for spareparts will in any case be lower, partly owing to the minimum number of parts that are subject to wear. The motor has but 2 moving parts of which only the gears touch each other; all other parts are contactless. The gears are, however, hardened and therefore have a very long life span.
A piston motor of this capacity has a minimum of 5 pistons, 5 connecting rods, a crank shaft and a rotary valve. All with very good clearances to limit leakage as much as possible. In the piston motor, there are a lot more parts that are subject to wear. The accurate clearances mean that this type of motor seizes up more quickly than gear motors, certainly when the quality of the air is not optimum (humid and/or contaminated).
In principle, the gear motor is completely maintenance-free if the air quality requirements that apply to all air-operated motors are satisfied. However, there are companies that routinely fit the winches and motors with new parts, such as oil seals, "O" rings, piston rings and bearings. In this case, we recommend that you choose a service interval that is at least twice as long.
For each type of motor, EMCÉ offers an exchange programme to customers who would rather not perform this work themselves. No special tools are required for stripping down and assembling the motors. The stripping down and assembly can be performed by qualified mechanics using the special assembly instructions.
Conclusion: the ingenious design resulted in a reduction of 50% in the number of parts used and consequently a reduction in the cost price of the product and the maintenance costs. Moreover, fewer parts are subject to wear and the motor's construction is compacter owing partly to the absence of an internal oil carter. External lubrication is still necessary with both motors.
Continuity
Underlying this is the forever decreasing number of suppliers of air-operated motors in general. Because EMCÉ guarantees all its customers that it will supply replacement parts during at least 15 years after the delivery of the winches, one feels obliged to oneself take on the production of motors. For the same reason, EMCÉ produces all its own piston motors (type LPR 6) - the largest piston motor currently in the market. Moreover, this type of motor will remain in production to continue to satisfy the replacement market needs.
Conclusion: EMCÉ can be and remain of better service to its customers by ensuring shorter delivery times in the short term and continuity in deliveries in the long term.
Designs
At this moment, various designs are available: a 3 kW (LG2), 12 kW (LG4) and 21 kW (LG6) version. However, the modular construction means that the motors of up to 55 kW also have the possibilities of gear motors. Local hand-operated control valves or pendant controls can be supplied with all motors. Both are proportional controls. The pendant control is also fitted with an emergency stop.
As mentioned earlier, both "full flow" and "biased" control valves are possible.
In addition, a programme of dynamic "failsafe" brakes is available. In contrast to many other brakes, they are not locking brakes (static) but dynamic brakes that can slow and hold a load.
The motors can be supplied including the required air-conditioning unit comprising a filter, pressure reducer and oil lubricator with the right bore to get the full power out of the motor. Units are available in the market with, for example, 2" connections that only have an internal bore of 1 ½".
The EMCÉ gear motor is therefore a real gear motor and thus a revolutionary design in a market where no developments have occurred in this field for 30 years.
MR 30 FLG
The MR 30 FLG is a good example of a winch that uses a gear motor. This winch uses type LG2 including an integrated brake and remote push button control. It is a winch for lifting people with a safe working load of 150 kg. The winch complies with all the stipulations stipulated in the standards of the certification institutes, such as Det Norske Veritas, Lloyd's Register of Shipping and American Bureau of Shipping. The MR 30 FLG has received a full type approval from these certification institutes. More than 60 of these winches have since been delivered to customers, principally in the oil and gas industry, such as NDC, KCA Deutag, Apexindo, Pride International, SWL, PPL, etc.
For more information, please contact Mr A.J. van Zaanen,
Machinefabriek EMCÉ BV, 's Gravendamseweg 53b, 2215 TC, Voorhout, The Netherlands
www.emce.nl, info@emce.nl
