Holroyd Precision Limited
Rotors from 10mm to 1m or larger
With an engineering history spanning over 100 years Holroyd is unique. Not only do we manufacture bespoke high precision components such as Rotors, Superchargers and Metering Pump Screws but we also make and sell the machine tools that produce them. This synergy means that in essence Holroyd is always its own customer, a situation that provides an ongoing database of manufacturing experience, which in turn benefits users of Holroyd products world-wide. As well as designing and manufacturing a range of Helical profile milling and grinding machines our product range covers Superabrasive machining systems, Thread grinders, DIN 4 to approaching DIN 1 standard Gear grinding machines and Gear, Thread and Rotor Support machines. From within our state-of-the-art manufacturing facilities we supply to major OEM's globally components produced on our machine tools. These include loose rotor sets in any size and quantity for use in applications as divers as Air Conditioning Systems to Transcontinental pipelines, Compressors and Engine Superchargers. We maintain a worldwide comprehensive support, maintenance backup and technical development and manufacturing advice service network, all readily available, just a phone call away, to ensure continuity of your production. Remember whether you're manufacturing or purchasing precision-machined components, Holroyd has a total solution for you.
PTG. The first name in precision.
Incorporating the world-class brands of Holroyd, Binns & Berry, Crawford Swift, PTG Heavy Industries and Precision Components, PTG has established itself at the forefront of high precision machine tool design, build and supply. The PTG range includes grinding machines for rotor, thread and gear operations, rotor milling machines and lathes producing ultra precision components to serve a wide range of industries from aerospace, medical and mould tool & die to marine, power generation, oil, gas, steel and high end automotive. The Group has developed some of the most sophisticated, bespoke software on the market from simple rapid set and intuitive user interface right up to on-machine 3D scanning, with automatic profile adjustment and offers technical consulting services, full turnkey packages and a remanufacturing facility for large capacity specialist machines for the steel, oil and gas and aerospace industries. And, across everything the group does, its watchword is precision. In fact, precision's not just PTG's middle name. It's its first name too. Precisely what's needed.
Part of The Precision Technologies Group of Milnrow, Lancashire, Holroyd Precision Ltd., has launched a revolutionary new machine capable of using all three grinding technologies, at the world’s leading trade fair for metalworking technology, EMO Hannover.
THE ZENITH OF GRINDING TECHNOLOGY
A great deal of industry excitement has already surrounded the launch of Holroyd’s new Zenith machine, Holroyd’s first with the capability to use the three grinding technologies of aluminium oxide, Electro plated CBN (cubic boron nitride) and vitrified (dressable) CBN. The Zenith machine will have the capacity to grind some of the largest rotors in the industry at 420 mm and offer the flexibility to use tooling from customers existing grinding machines.
This is a new generation of grinding machine technology, encompassing modern innovations, coupled with an exciting new easy feel control system that incorporates both a development and production software suite to suit all potential user requirements in either research and development or mass production.
A CUSTOMERIZED SOLUTION
For Holroyd, a profound understanding of customer issues, challenges and concerns is the foundation upon which each and every new development is built.
The company regularly carries out ‘Voice of customer’ studies to determine the course any technological innovations need to take.
And the findings of one such study, carried out in 2008, provided Holroyd with some significant pointers. First and foremost, the study revealed increasing demand for greater component diameters. High productivity without any compromise of rotor accuracy, was, unsurprisingly, found to be a major requirement. Users with stable product lines were willing to sacrifice profile capability in favour of a process which was simpler to operate and offered shorter cycle times making the ability to use both dressable and plated wheels on the same machine highly desirable. Software features needed to be simple and easy to learn in addition to offering greater flexibility and versatility. Customers spoke of the need for faster, easier set-ups making less onerous demands on operators without any loss of accuracy. Machine diagnostics need to be overhauled and coolant delivery improved.
RESPONDING WITH SOMETHING MORE RESPONSIVE
In response to these detailed, the team at Holroyd set to work designing and developing a machine that could truly be described as representing the next generation of helical grinding machines. The new Zenith machine is an extremely compact machine that gives high loop stiffness, good thermal resilience and rigid work holding. The machine’s increased diameter capacity can accommodate components of up to 420 mm. in diameter. Thanks to careful orientation of axes and guide-way layout, overall length capacity could be increased with a reduction of machine footprint. Use of a single-piece iron casting using precision ground linear guideways removed traditional constraints regarding the orientation of the guide-ways. While disassembled the entire machine and coolant filtration system will easily pack into 40’ shipping containers, facilitating transportation as well as reducing the factory space required. A two-wheel arbour with wheel slide allows two non-dressable grinding wheels to be mounted simultaneously, a high speed spindle offers 6,200 RPM capability and when required, a twin-wheel dresser caters for all types of dressable wheel, a live spindle drum rotation axis offers increased angular capacity to allow the grinding of components with zero lead angle, such as spur gears, while the drum-mounted probe increases probing range for the continuous probing of ‘normal’ components with the capability to access both ends of extra long components.
HANDLING EVERY TASK WITH EASE
The new Zenith machine is as user-friendly as it is efficient. Ease of access is significantly improved through a unique slideway design. A software ‘wizard’ guides the operator smoothly and efficiently through the CNC programming without the requirement for high levels of expertise while still offering options for personal operator control. Operator-free coolant application eliminates the possibility of human error. An inductive flute-finding probe allows rapid orientation of the part. Simultaneous probing of both journals measures the run-out of the blank before grinding. Work pieces are automatically loaded and extracted. Power-assisted doors provide easy access at the touch of a button. Fast mist extraction prevents coolant mist from escaping into the workshop when the doors are opened. Full automatic vitrified wheel balancing and Radio Frequency Identification chips and reader make the operator’s life easier still. While dresser touch detection enables the machine to locate the position and profile of the grinding wheel to ensure economic dressing.
MORE EFFICIENT, MORE ENERGY EFFICIENT
In designing the new Zenith machine, the Holroyd development team was careful to be as sensitive to the environment as it was to the needs of its customers. In the light of this, a warm up cycle mode was incorporated to avoid leaving the machine running for long periods when not in use and to provide thermal stability. Auxiliary units such as the coolant filtration and chiller system are under central control and so can be switched off into ‘sleep mode’ when necessary. Coolant flow is controlled to avoid excessive application, reduce the heat generated from pumping the fluid and the energy used to filter it. A directly-mounted backlash-free torque motor, meanwhile, reduces cost, build time and performance degradation.
As Rod Macdonald, Managing Director of Holroyd Precision explains:
“The development of the new Zenith machine has provided an exemplary case study of the way in which we like to operate here at PTG. By taking as our starting point the concerns and considerations of our customers through a thorough and exhaustive market study, we believe that ultimately we have been able to develop an entirely new generation of helical grinding machines to satisfy the demanding needs of accuracy and versatility on the one hand and productivity and ease of use on the other. While the important and newly- emerging consideration of energy efficiency was also a very important factor in the development of what we believe to be a truly groundbreaking machine.”
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Rotor Grinder Handles Helical Screw Components
The TG 350E rotor grinding machine from Precision Technologies Group’s Holroyd Machine Tools and Components division is designed to grind a variety of helical screw components.
Grinder Combines Three Technologies
The Zenith grinding machine uses three grinding technologies—aluminum oxide, "diamond-hard" plated cubic boron nitride (CBN) and vitrified CBN—to grind rotors as large as 420 mm.
Precisely Grind Helical/Spur Gears
The Holroyd gear and thread grinder, GTG2, is designed for precision grinding of helical/spur gears in diameters ranging to 350 mm. According to the company, the machine can grind small batches of these gears to high levels of DIN and AGMA quality standards.
Getting In Gear With An Automated Cell
This production cell embodies several unusual but very effective concepts for keeping process variables under control with little operator intervention.