Machining operations complemented by the development of in-house foundry
at Gear Pump Manufacturing.
Gear Pump Manufacturing (GPM) is located in Cape Town, South Africa and has been involved in the manufacture and assembly of SAE mounted pumps and components since inception. These components include gear sets, shafts, gear housings, end covers, bearing carriers, thrust plates, bearings and bushes, seals, retainers, dowels spacers, keys, fasteners, rings and clips and other small part components.
Approximately 70% of the company’s production is exported to countries in North and South America, Europe, the Middle East, South East Asia, Africa and Australasia.
When GPM opened its doors for business in 1985 the company relied on a foundry that was located ‘down the street’ from its main facility, for its casting requirements.
“Gearings Foundry had always been a reliable supplier and we never had a problem with them. However we had to make a big decision in the company’s history when Gearings management shifted the emphasis of their business and we did not fit into their plans going forward. We either had to look for an alternative supplier or open up our own foundry,” said Tony Payne, GPM founder and MD, at the time.
“We decided to go the in-house route because we did not want to end up in the same position again. Additionally we did a feasibility study and found that potential suppliers were just too far away from us. We realise that the foundry business is not our core business but the move is also a strategic one in that not only will we be in control of our own destiny, but will also improve our costs, our competitiveness and boost our profitability,” said Payne.
That decision was taken back in 2001 and current management says thank goodness Payne and his colleagues had the foresight and were brave enough to move into the foundry industry. Since then the GPM foundry, known then as Engineering Technology Services (Pty) Ltd, has flourished and Gearings Foundry, which was established in 1876 and changed its name to CME Foundry in 2005, ended up on the scrap heap in 2009.
In order to accommodate the foundry a new building was constructed on the existing GPM premises in Epping Industria, Cape Town.
Two one-ton Inductotherm melting furnaces with VIP controls were sourced from the UK and core shooters, a sand mixer and a shotblast machine were acquired from Gearings. A new sand plant, a turnover strip machine and a vibrating table were ordered and soon GPM had their own foundry up and casting. Although they had been getting their castings made via green sand at Gearings, with their new foundry GPM decided to change to a furane resin based sand system. The foundry also reclaims most of its sand.
More recently the company has invested in an Oxford Instruments spectrograph.
Initially the foundry had a compliment of eight staff but this has now grown to 29 on a single shift basis. So have the tons of metal cast per month. Twelve years ago 35 tons of grey iron and SG castings were cast on average per month. This has now grown to a 100 tons melted or which 60 tons are saleable castings per month with a mix of 40 percent CGI and SG castings and the remainder made up of grey iron.
Without the pressure of having to supply castings outside of the business, the company still manufactures on a ‘just in time’ basis to suite their own requirements. The company also has over 200 different patterns in its store and some castings manufactured weigh up to 21 kilograms.
Machining and assembly
The primary focus of the business is the manufacture, assembly and repair of SAE mounted pumps and components. As this side of the business has grown so has the foundry. Physically, the foundry has been expanded by more than 50% since its inception in order to cater for the increased volumes.
Sustained and rising demand for scrap metal has made prices climb worldwide, particularly for the premium grades of scrap so valuable to primary steelmakers and iron and steel foundries. With this in mind and in the interests of the environment and to further contain costs, the company has invested in a swarf pelletising machine. Consequently, a large portion of the foundry raw material is obtained by pelletising iron and steel swarf and off cuts from the GPM machining facility. Bronze castings for the machining of thrust plates are produced in a similar fashion. Reclaimed machining coolants and cutting oils are also recycled.
The foundry enables GPM to ensure the quality of the castings that are used in the product range, which includes hydraulic bushing pumps, bearing gear pumps, power take offs and some valves. Up to 10 000 castings of various shapes, sizes and weights are manufactured monthly and the synergies can be clearly seen between the foundry and machine shop.
Before the castings can be used they must undergo precision machining and as a result GPM has been equipped with numerous state-of-the-art CNC machines and specialist task performing machines. On the shopfloor there are 13 machining centers, six CNC lathes, two CNC angle approach grinders, a surface grinder and six gear hobbing/shaving machines.
With the numerous amounts of and the variety of castings needed to be machined every day the machine shop is operating three shifts a day, five days a week. However it is not just machining castings. Forgings and bar stock are also amongst the mix.
Assembly, testing and other operations are also an important aspect of the company. For example it has its own deburring department using ceramic abrasives and additionally there is the heat treatment department.
The volumes of pump assemblies have more than quadrupled during the last few years and this necessitated the construction of a new and substantially larger pump assembly area, as well as new and upgraded test stands. All assemblies are tested on computerised test stands, which have multiple flow, pressure, temperature and speed testing capability.
The shop continues to add to its wealth of internal manufacturing capabilities as needs arise. Having nearly all requisite processes in-house and performed by trained shop personnel not only allows quicker deliveries to customers, but helps to ensure that the documentation is properly maintained for every job.
Quality assurance
The company been accredited in accordance with the ISO 9001-2008 standard since 1992 and the quality management system makes use of statistical analyses to determine manufacturing process capability. The stability of manufacturing processes is continuously monitored and managed via machine run charts. In line with GPM’s technology investment philosophy, they have recently invested in a 3D co-ordinate measurement machine. This has increased productivity by means of faster first-off measurement as well as enabling expanded statistical sampling checks.
History of Dosco GPM Holdings
Tony Payne, who is now retired, established GPM in 1985 and was instrumental in establishing the foundry in 2001. Before that the company tied up with Dosco Precision Hydraulics (established 1989), a company focused on hydraulic pump repair and remanufacturing, based in Johannesburg. Together the companies formed Dosco GPM Holdings (Pty) Ltd in 1998.
In 1999 Dosco GPM Holdings acquired a 100% interest of Debex Cape (Pty) Limited (established 1988) which was renamed (GPM) Gear Pump Manufacturing (Pty) Limited. GPM manufactures a comprehensive range of both bearing and bushing cast iron gear pumps / motors and flow dividers.
The holding company is continuously searching for ways to improve service levels and effectiveness throughout the world. In 2000 (GPD UK) Gear Pump Distributors (UK) Ltd, located in Bromsgrove, Midlands, was created to distribute the GPM product throughout the United Kingdom, Europe and the Middle East. This dedicated pump workshop is able to assemble, test and despatch units the same day.
In 2003 (GPD AUS) Gear Pump Distributors Australia (Pty) Ltd, located in Sydney, was created to distribute products manufactured by GPM into the Asia Pacific region.
In 2004 (MTS) Manufacturing Technology Services (Pty) Ltd. was set up to manufacture specialised housings, shafts and couplings primarily for DPH. As such, MTS is a specialist machine shop and is equipped with all the necessary machine tools to perform this function. This concept proved very successful and MTS now performs work previously done by subcontractors and to a higher quality standard and quicker turnaround time.
Precision Hydraulics International was established in 2008 to oversee the Groups international operations.
Dunford Holdings
In 2011 Dunford Holdings acquired a majority shareholding in Dosco GPM Holdings. Dunford Holdings is based in Durban and is headed up by brothers Tommy and Graham Dunford. Included in the Group is another foundry – Jos Grieveson – a versatile KwaZulu Natal foundry producing ferrous and non-ferrous castings for the sugar, valve, mining, heavy duty vehicle, motor, crusher, shipping and general engineering industries in KwaZulu Natal, as well as Gauteng.
Since the acquisition, all companies have been consolidated under one group structure although they continue to trade under their individual names.
For further details contact Gear Pump Manufacturing (GPM) on TEL: 021 531 9330 or Dunford Holdings on TEL: 031 507 3640 or visit www.gearpumps.co.za
GPM management: Gerry Coward, Mark Frankin and John Barnard
Metal being transferred to a ladle. The foundry makes use of two one-ton Inductotherm melting furnaces with VIP controls
Castings in the cooling process
A general view of the foundry
Castings that still need to be machined
Machining, assembly and test of components forms a big part of the company
The volumes of pump assemblies have more than quadrupled during the last few years and this necessitated the construction of a new and substantially larger pump assembly area, as well as new and upgraded test stands. All assemblies are tested on computerised test stands, which have multiple flow, pressure, temperature and speed testing capability.
Various stages of machining of a component from blank
Grinding operations are carried out on specialist machines
GPM runs a number of Leadwell machining centres and lathes supplied by WD Hearn
Gear machining forms an integral part of the machining operations
