Tuesday 19th September 2017

Precision hub and shaft clamping

One of the most innovative products on the market, the ETP product consist of a double-walled hardened steel (in some cases stainless steel) sleeve, which is filled with a pressure medium. The precision machine housing contains a threaded pressure screw, that when actuated, moves an internal piston that in turn provides the pressure adjustment. By tightening the pressure screw to a predetermined torque, an even and moderately high surface pressure is created against the shaft and hub, causing the locking effect.

The scientist Blaise Pascal formulated the principle of pressure propagation in liquids many years ago: Pascal's law or the principle of transmission of fluid-pressure states that , ”pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure ratio (initial difference) remains the same”. The ETP product utilises the many positive qualities of this principle and has continued to develop it further so that it can be utilised reliably and accurately within industrial applications.Whether the hubs are to be removed or repositioned, mounting and dismantling the process is done in less than a few minutes. 

With product names like ETP EXPRESS, ETP EXPRESS R, ETP POWER and ETP TECHNO, these products are, as it sounds, designed for a multitude of applications. In each case only a single screw is used for mounting and dismounting of the hub. This simple feature ensures an extremely quick and easy service interval time and incredibly easy adjustment or repositioning of the hub. The single screw hubs are used in a variety of applications and industries such as packaging, food, beverage and pharmaceutical. The standard ETP-TECHNO and ETP-EXPRESS are available for shafts 15mm to 130mm. ETP-EXPRESS R, Stainless steel versions, are available to suit shafts from 15mm to 80mm.

The Future

Keyway's, will always have a legitimate place in power transmission, but when you need finite adjustment of the driven shaft, keyways are not ideal. The taper lock design allows the positional movement but they are time consuming to fit, release and then re fit. The design is also prone to  corrode and become fixed to the shaft over time. Lastly, the taper lock design requires that there is taper on the inside diameter of the driven part, for the device to lock in position and also requires more space to fit because of the bolting circle.

 

 

 

  

Small built-in dimensions saves the day

In this industrial cleaning system for use in the automobile industry, ETP-EXPRESS R is used for fastening of the cleaning head brushes. The minimal dimensions and excellent concentricity meant less vibration within the system, whilst providing a resistance to fretting corrosion. One of the main advantages was the speed and ease that new brushes could be interchanged. 

 

 

Reliable and accurate positioning

The gears in this food processing machine can be repeatedly and accurately adjusted during assembly by fitting the ETP-EXPRESS R product.  In the application it was found that over time wear to the gears made finite adjustment necessary. Due to the unique design this porcess is done easily as only one screw needs to be loosened and re-tightened. The Stainless Steel ETP Express R also helped reduce noise levels and vibrations.

ETP HYLOC - Taking marine applications by storm

The ETP product is delivering a new paradigm in torque transmission capability, reliability and ease of maintenance marine power transmission systems make stringent demands on shafts and clamping components. Not only must they deliver high torque capacity, but they must also offer high levels of reliability combined with ease of maintenance. Marine power transmission systems can require frequent disassembly for maintenance, so quick mounting of dismounting is an essential feature. Then there is the challenging marine environment and the fact that there is often very little space in which to work.

As yachts increase in size, outboard propulsion systems quickly become inappropriate, whilst on the very largest yachts and highest powered craft exotic propulsion systems such as water jets are becoming fashionable. But for yachts between 40 and 100 feet in length, from luxury yachts right up to the so-called super yachts, by far the most common propulsion arrangement where speeds above 40 knots are not required is the in-board drive with conventional submerged propellers. All propulsion systems have their advantages and disadvantages, but in-board drive lines benefit from an inherent simplicity and, when properly maintained, a near unlimited life. The emphasis on maintenance is crucial. The underwater appendages are subject to shock and there will always be inherent vibration.

 

Excessive vibration would likely indicate serious wear due to misalignment, but there is inherent misalignment in all in-board propulsion systems: the engine is installed on rubber mounts and the shaft is mounted in rubber bearings, so both engine and shaft can move. In addition, the boat hull itself is not completely rigid so there is more potential for movement.

Maintenance is further complicated by the fact that space is at a premium on yachts even of the very largest sizes, and in-board drives are often installed in areas where there is very little working space. This also impacts on power, with the torque handling capacity of a conventional coupling directly related to its physical size. So in a traditional in-board marine engine, the coupling between the engine and the shaft is one of the primary limiting factors in the maximum torque capability of the drive train. Traditional shaft clamping components fail to address all of these issues. Most mechanical shaft connections require numerous bolts; in the cramped engine and shaft tunnel, this makes the shaft a challenge to install and certainly does not facilitate easy maintenance. As well as the time and effort involved in working with so many bolts, there is also the potential to mark the shaft during assembly, which can be detrimental to the friction joint and so impact on torque capacity and increase the likelihood of premature corrosion. The ETP Hyloc uses the same locking principle as the smaller ETP units mentioned above, but uses a detachable hydraulic connection for the lock and release..

  

The product advantages

The quick and easy clamping of shafts
The quick release capability
Strong and reliable clamping forces
Precision tolerance bores with excellent concentricity.
High torque transmission
Excellent radial load capability
Removes the need for keyways

Can we help?

With over 30 years' experience and knowledgeable staff always available, please do not hesitate to contact our sales engineers on 01386 421 005. We will be more than happy to help, so please call today!

For more specific information follow the link : ETP  

For explanatory videos on the product follow this link - ETP Videos