JBJ Techniques Offers Marzocchi Sealing System

Marzocchi Pompe has produced a system of radial sealing at the shaft that is claimed to be able to bear enormous internal over-pressures without resulting in damage. This radial sealing is useful in single-direction hydraulic motors when, in certain conditions of use, high over-pressures will be generated at the motor output. With bi-directional motors, the area adjacent to the seal ring of the drive-shaft is maintained at atmospheric pressure by the drainage circuit.

In single-direction motors, this area is directly connected to the output so any over-pressure impacts directly on the seal ring, causing the lip to turn over or the ring to be expelled from its seat with a consequent leakage of fluid. These products can also be supplied complete with anti-cavitation valves. The motors are supplied with an internal drainage circuit. In this case, the hydraulic motor always drains inside with a lower pressure; the combination of this product with a high-performance sealing ring increases its reliability.

Marzocchi Pompe's solution is made up of a single-lip radial seal ring in a Teflon composite material and reinforcement ring, both of which are the result of a special design and construction process. The external reinforcement ring fully follows the form of the seal ring and has been sized to bear the axial force generated by internal over-pressures. Before performing laboratory tests, it was necessary to strengthen the entire system that fastens the ring onto the flange, so that it could bear all the stresses submitted to the ring. The best characteristics with respect to the components were determined with FEA software.

The new radial seal ring has a much stiffer structure than normal rings, making it necessary to employ special assembly procedures. The Teflon (P450) material adapts evenly to the texture of the machining on the shaft to guarantee a perfect seal. Because of the internal pressure, the lip of the seal ring is constantly compressed against the shaft. The increase in pressure is accompanied by an increase in friction, with heat being generated in the sliding zone as a result. The properties of the P450 material make it possible to bear high-pressure loads, strong friction and temperatures between -30 and +200C.

To guarantee a long operating life, it was necessary to perform in-depth research on the methods for grinding the area where the sliding of the seal ring's lip takes place. Validation tests have revealed that the system is able to work on a continuous basis at a constant pressure of 30 bar (430psi) without the spilling of fluid and without the ring and the shaft exhibiting wear. Tests performed at higher pressures also demonstrated the possibility of the system functioning for short periods of time (several minutes) with over-pressures of up to 140 bar (2,030psi). If the operating conditions must be maintained with extremely high over-pressure values (80-100 bar/1,160-1,450psi) for prolonged periods of time (more than 30 minutes), the heat generated by the friction between the ring and the shaft can result in temperatures of more than 300C.

This will play a part in deteriorating the structure of the P450 material used in the seal ring, as well as compromising the ground profile on the shaft, and thereby reduces its sealing function. In the presence of pressure peaks, for example, caused by errors of manoeuvre or an incorrect timing of the valves of the hydraulic circuit, or in static conditions, with the shaft immobile, this sealing system can bear over-pressures of more than 210 bar (3,050psi) without leading to any loss of fluid or deformation of the components. The characteristics of this product make it particularly suitable for applications that function as appendages of other machines without knowledge of the exact circuit characteristics.

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New Scale Unveils Squiggle RV Linear Drive System

New Scale Technologies has introduced the Squiggle RV reduced-voltage linear drive system, which consists of an SQL-RV-1.8-6-12 Squiggle motor and an NSD-2101 drive ASIC. It is a miniature piezo motor drive solution with a driver chip that is smaller than the motor and driven directly from battery power as low as 2.3VDC, without the need for a voltage boost. The Squiggle RV motor is New Scale's next-generation piezo micro motor, using multi-layer piezo technology from TDK-EPC to reduce the input-voltage requirements of the motor.

The NSD-2101 driver was developed for this new motor in partnership with Austriamicrosystems using advanced integrated-circuit (IC) designs and patented control systems. This smart IC measures 1.8 x 1.8mm and drives the Squiggle RV motor directly, without the need for an external boost circuit. The Squiggle RV linear drive system is more than five times smaller and uses 40 per cent less power than comparable electromagnetic linear drive systems, according to New Scale.

The NSD-2101 accepts direct 2.3-5.5VDC battery power and uses patented full-bridge switching technology to create the ultrasonic motor drive frequency. The IC also includes built-in patent-pending smart drive features that optimise motor performance while minimising power consumption over a range of operating and environmental conditions. The NSD-2101 requires only DC battery power and digital I2C control commands to achieve good miniature motion control performance.

The SQL-RV-1.8 motor achieves forces in excess of 50g and a high resolution to 0.5 micrometers. It can run at speeds greater than 7mm/s with a power consumption of less than 350mW when moving under typical loading conditions. This corresponds to a DC current of 120mA for a typical 3VDC battery. Its self-locking design means that zero power is needed to hold the motor position, providing additional power savings. New Scale's Tracker NSE-5310 linear encoder can be integrated with the Squiggle RV system for high system repeatability with submicron resolution.

The reduced-voltage Squiggle RV micro motor is suitable for situations where high precision, miniature size and low power consumption are a must. These include medical, security, optical and imaging systems; consumer electronics; precision biomedical actuators; and miniature actuation for aerospace and industrial applications. Its small size makes it suitable for creating tiny, high-resolution integrated closed-loop motion systems.

New Scale's DK-RV-1.8 series of developer kits includes all hardware as well as the company's Pathway development software with scripting capabilities in a plug-and-play reference design for prototype development and integration. Open-loop developer kits contain an SQL-RV-1.8 micro motor and an NSD-2101 driver; closed-loop kits also include a New Scale Tracker NSE-5310 linear encoder. A 3D computer-aided-design file of the SQL-RV-1.8 motor and additional reference information is available from the company's website.

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Vehicle Power System Uses Mattei Vane Technology

Mattei is demonstrating the durability and energy efficiency of vane technology through a partnership with Winton Engineering. Winton's onboard-power system utilises the power of a vehicle's engine to drive auxiliary tools and equipment. These modular systems utilise the Mattei vane compressor and can be supplied with a 6kW 110/240V generator. The complete module is powered through the Winton Drive Line Power Take Off (DLPTO).

Winton systems are installed under the vehicle and deliver compressed air up to 160cfm. These systems are installed on a range of vehicles and are predominantly used by civil-engineering and utilities companies to power equipment such as road drills, breakers and site lighting. Andy Gear, Winton Engineering, said: 'We chose Mattei compressors as we believe vane-compressor technology is more efficient than traditional screw- or piston-driven compressors; it reduces the demand on the vehicle's engine and generates less noise and heat.

'The result is a powerful, energy- and fuel-efficient system that makes a significant contribution to whole-life operating costs. 'It's also virtually silent in operation, so is suitable for continuous running. The air end in Mattei's rotary-vane compressor comprises a rotor with longitudinal slots that house individual sliding vanes. The rotor is offset within a stator (a cylinder), in which it rotates.

While the rotor turns on its axis, the vanes are pushed against the stator wall by centrifugal force, and the air is compressed. Andy Jones from Mattei said: 'Our technology is the optimum solution for tough conditions. 'The vane compressor's rotor shaft is supported by simple white metal bearings, which ensure a long and inexpensive operating life. He added: 'An air end can easily run for 100,000 hours without wear - in fact, some Mattei machines have lasted over 230,000 hours in the most arduous operating conditions.

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Linear-Rail System Has Self-Adjusting Mechanism

The SBI range from Jena Tec offers low noise and high rigidity, coupled with a smooth movement and self-adjusting mechanism. According to the company, an increase of load-carrying capacities of up to 40 per cent can be achieved compared to standard block and rail systems. Compared to conventional linear rail cross sections, the SBI range is approximately 10 per cent lower, with a wider through section of nearly 20 per cent, Jena said.

Its improved lower cross-sectional centre point offers greater structural rigidity, improved straightness during manufacturing and straightness in application. Heat treated to HRC60, the SBI range is highly stable, while shorter cross-sectional areas mean grinding time and plastic deformation are reduced. Linear blocks are constructed from a hardened-steel rigid structure with the same lower cross-section centre as the rail and slightly longer block length meaning a greater number of balls with a smooth circular-angular motion.

This improved track profile and angle results in a smoother and quieter operation. Standard across the range of SBC products is the heat- and chemical-resistant end plate with moulded return systems and a self-aligning design to ensure the end plate is correctly fitted in line with the main steel block. Despite an increased load-carrying capability, the additional length attributable to the SBI range is approximately only 3-4mm longer than standard types, dependant on carriage model, which is made possible by an improved end-plate design.

Upper and bottom retainer plates fitted to each block ensure that loose steel balls are eliminated, as well as skidding and poor rolling performance within the load zone, preventing ingress of foreign substances. The SBI retainers are snap assembled and self aligning. The moulded return plate contributes to the smooth running operation of the SBC range, as well as keeping running noise low. The SBI range achieves this through an improved contact angle of 52 per cent, versus the industry standard of 53 per cent.

The lower radius of curvature provides a broader contact surface compared to the relevant ball size possible and therefore improves the rigidity. The improved angular ball recirculation system with four-row, two-point contact and 45deg angular orientation ensures that rolling performance is maintained with low noise at all grades of pre-load.

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Fanuc Robots Automate Green Pallet-Handling System

Fanuc Robotics has revealed that two of its robots are being used in a Green Solutions system that manufactures pallets made from paper pulp. The manufacturing process is automated from the input stage, where the paper is in a slurry form, right through to the output stage where the finished pallet is ready for use. Central to the process are two Fanuc Robotics robots, which handle the mould and moulded pallet and also control the system process.

Green Solutions supplies the complete manufacturing system to businesses requiring either one-way or multi-transport pallet use for their product deliveries. As systems can be supplied anywhere in the world, sourcing a reliable handling solution for the moulding process was important as it forms the core of the process. Samey, an Icelandic automation business, worked with Green Solutions to design the handling system. Thorkell Jonsonn, managing director of Samey, said: 'Robots were the most cost-effective solution for the process and provided a highly supportable answer to reliability and ease of production. At the beginning of the process, robot one - a Fanuc Robotics M-900iA - dips a mould into the paper slurry.

After a short period of time, the mould, weighing 250kgs at this stage, is removed and a vacuum applied to the top surface of the pallet to remove water. After the first vacuum operation, the robot rotates the pallet and delivers it to a static vacuum device, which extracts water from the other side of the mould. The pallet is then transferred to robot two - a Fanuc Robotics M-2000iB - which applies its vacuum gripper to the pallet while robot one ejects it from its gripper.

When robot two signals that it has made a vacuum, robot one departs the transfer area and continues with another dip operation. Robot two at this point loads the pallet into one of six drying ovens. The Fanuc Robotics controller manages the sequence for all six ovens, including door operation and heat blow, allowing it to instruct the robot to unload the correct oven and place a finished pallet into an output conveyor.

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Alumasc Waterproofing System Specified For Academy

Derbigum waterproofing membrane and Harmer roof outlet drainage systems from Alumasc have been installed at the Harris Academy in London. Alumasc's Technical Support Team worked in close partnership on the project to make Harris Academy the latest addition to Alumasc's portfolio of successful high-profile academy projects. Alumasc's high performance Derbigum Waterproofing Membrane was specified for the building, helping to meet a late challenge set by Croydon Council, who requested a 10 per cent reduction in carbon emissions throughout the construction process.

Derbigum Mineral Grey was installed which offers flexibility and ease of application. Derbigum Mineral is a BBA approved 4mm membrane with a protective mineral finish available in five surface options. It is manufactured under the ISO 14001:2004 Environmental Management Standard, meeting the Council's sustainability requirements. In addition, the system is fire rated F.AA to BS476 Pt3 (EN1187 Pt4), which allows unrestricted use under the building regulations.

Harmer AV400 Roof Outlets from Alumasc were also specified, providing a robust drainage solution that will perform for the lifetime of the Academy. The AV range provides a comprehensive choice of high performance outlets suitable for all regular flat roofing applications with continuous membrane systems. Harmer AV Roof Outlets are available with spigot or screw connections for vertical, horizontal or 45 discharge.

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