PTG Holroyd’s recently launched HG350 gear-grinding centre

Rochdale-based PTG Holroyd has selected high-torque, low-backlash precision planetary gearboxes from Uttoxeter-based Apex Dynamics’ APC and AD ranges, for use in its ultra-precise helical rotor grinding machines. Founded in 1860, and with more than a century of experience in the manufacture of helical components, PTG Holroyd, a Precision Technologies Group (PTG) company, is a world-leader in its field. It produces high-precision gear, rotor, screw and thread milling and grinding machines for a range of sectors including the compressor industry. All PTG Holroyd products are built to exacting specifications by a team of expert engineers, fitters and electricians.

Gearboxes are an integral part of PTG Holroyd’s technology as they drive the axes in its machines, making accuracy and precision key. The company had very specific requirements for output torque, accuracy and product dimensions, and was looking for the gearboxes that best fulfilled them. PTG Holroyd approached planetary gearbox specialist Apex Dynamics with a set of tight specifications for its helical grinding machines, which Apex was able to meet with its APC and AD series of gearboxes. Working alongside PTG Holroyd’s engineers and design teams, Apex identified the best possible products for the machine tool manufacturer’s helical grinding machines. This prompted PTG Holroyd to use Apex for a number of its planetary gearboxes.

The specific Apex Dynamics’ high precision planetary gearboxes best-suited to PTG Holroyd’s helical grinders were from the APC-Series of rotary flange style gearboxes (with 55 to 1 ratio) and the Apex AD-Series of compact gearboxes (with 50 to 1 ratio). Both Apex product ranges deliver high torque, low backlash of less than one arc-minute and superior levels of accuracy; ideal for PTG Holroyd machines.

High wear resistance
The APC-Series comes with a patented curvic coupling output, giving a high concentricity, low run-out, high-torque, zero-backlash connection. Its case hardened and ground gearing offers high accuracy and high wear resistance for the gear train, and by adding a fourth planetary gear torque capacity is boosted by up to 25%. The compact helical, one-piece planetary cage design of the Apex AD series provides PTG Holroyd with a range of benefits, including the stiffest and most accurate rotating flange design currently on the market. It can deliver superior accuracy of less than one arc-min with as short as 70mm flange- to-flange, making it capable of fitting into the smallest spaces.

PTG Holroyd has praised the reliability, strong customer support and engineering knowhow provided by Apex, which has worked closely with the business to ensure its precision planetary gearboxes are supplied quickly. Purchasing products directly from Apex means PTG Holroyd is able to take advantage of the excellent delivery times Apex offers its customers. Apex guarantees delivery within 3–4 weeks and provides a total supply package of high-quality products, accurate and efficient quotes, fast delivery, good customer service, excellent technical information and ongoing support.

Philip Hart, PTG Holroyd technical director, said: “We have been using Apex Dynamics products for some time in our machines and have been very pleased with the relationship we have built with the company. When we looked for the correct gearboxes for our high precision applications, we found Apex products to be very reliable and able to meet our high standards for speed, accuracy and precision at the interface between motor and machine.”

Malcolm Hillary, Northern area manager for Apex Dynamics UK, concluded: “PTG Holroyd is a great company to work with and has a rich history. Our product range and customer support is ideally suited to its advanced high-precision helical grinding machines. I truly believe we offer the best gearboxes in the world and a unique full-service package that is unsurpassed in the industry. With 49 series of gearboxes, more than 20 years’ industry experience, and the highest level of technical production capabilities, we can supply the best-possible advanced high speed, low backlash solutions for any needs — that is why we are winning more and more business across the UK.”