UNSCHEDULED and extended downtime are two setbacks that production managers do their best to avoid. To help extend uptime in all hydraulic equipment, machinery and applications, Bosch Rexroth South Africa Group companies, Hytec South Africa and Hytec Engineering, offer comprehensive hydraulic repair services for the group’s entire hydraulics range.
These repairs are done in a new facility in Kempton Park
Repair services for hydraulic pumps, motors, gearboxes and valves falls within the scope of Hytec South Africa, while Hytec Engineering, as group specialist in hydraulic cylinders, repairs and refurbishes all OEM cylinders distributed by Bosch Rexroth South Africa.
All repairs and refurbishments are according to Bosch Rexroth specifications which include OEM specifications, with all work and componentry warrantied for 12 months.
“Our hydraulic repair services are all ISO-accredited and cater to any application,” said Ian Kidson, Repairs Manager, Hytec South Africa. “From highly complex hydraulic systems specifically designed to meet stringent requirements of local and international customers, to simple componentry that is fit for purpose, our service and hydraulic repair offering is always OEM-compliant.”
In addition to ISO compliance, Hytec South Africa and Hytec Engineering are Bosch Rexroth-Certified Service Centres of Competence. This certification, renewable every four years, certifies that these two Group companies have the processes, infrastructure, qualification and management abilities to perform service work to quality standards specified by the worldwide Bosch Rexroth Service Centre grades.
These two companies, along with Group Company Tectra Automation, are the only Bosch Rexroth-Certified Service Centres of Competence in Africa.
All hydraulic equipment undergoing repair or refurbishment is subjected to calibration, analysis and fault-finding, with engineers and technicians accessing all specifications including OEM specifications from Bosch Rexroth’s SAP program.
“The information includes parts lists, repair procedures and e-learning, which provides specifics on methods to repair units to OEM standards,” Kidson said.
All parts are inspected for wear and damage, with affected components replaced new and all seals, bearings and bolts are a mandatory replacement. The hydraulic equipment receives OEM replacement parts, manufactured by Bosch Rexroth Germany. Exchange units for all of these applications, barring hydraulic valves, are on-hand for qualifying customers – significantly decreasing their downtime caused by faulty equipment.
The gearbox repairs facility carries out repairs to all Bosch Rexroth gearboxes and other mobile shovel gearboxes like ZF, O&K, Stiebel, Siebenaar and Zollern brands. “Only original parts are used for replacement,” Kidson said. “Although, on the rare occasion and only in consultation with the customer, parts can be repaired or manufactured using reputable gear manufacturing companies.”
Hytec Engineering retains an extensive and comprehensive stockholding of refurbished cylinders, which facilitates its cylinder exchange programme. “Under this offering we are in a position to immediately replace damaged or worn cylinders so clients avoid waiting for lengthy repair procedures,” said Andre Lindeque, General Manager Hytec Engineering.
Hytec Engineering has three hydraulic cylinder test benches, ensuring its cylinder repair and refurbishment capacity and capabilities cater to the requirements of numerous cylinder types and sizes. The smallest of the three test benches is for high flow and low pressure testing, capable of 102 l/min at a maximum pressure of 10 MPA, after which high pressure testing up to 55 MPa can achieved and end-of-stroke and mid-stroke testing occurs.
A fully automated test bench that tests up to 42 MPa is also used, and cylinder specifications are selected via software for this method, with each cylinder individually tested. A laser guided system records closed centres, stroke and open centres, and mid- and end of stroke tests are also conducted. All recordings and values are included in the client report.
“Our most recent addition to our test bench range is the Micron technologies stripping bench,” Lindeque said. “It has been designed for stripping and reassembling larger cylinders and, using Hytec technology, it performs autonomous testing.”
Designed by Group Company Tectra Automation, the stripping bench incorporates a laser creep measurement function, which ensures zero by-pass in the mid-stroke position pressure test. Both single- and double-acting cylinders can be tested on this bench.
Hytec Engineering recently acquired a Hydrotechnik data logger, allowing the company to precisely measure movement, pressure deviations, cushioning function and the performance of all cylinder functions during testing.
Four pump and motor test stations, from 90 kW to 600 kW, are used on the pumps and motors. Each test station is connected to data recording stations, including CADASYS, a Bosch Rexroth data acquisition system, to which Bosch Rexroth South Africa has access. All results are saved to the Bosch Rexroth server for easy retrieval worldwide.
Two valve test stations are used in the service offering, one for standard valves and the other to test proportional and servo valves. The proportional and servo test station is also connected to a Bosch Rexroth data acquisition system where test reports are acquired and stored.
Catering to onsite hydraulic repair requirements, Hytec South Africa operates a fleet of service vehicles equipped to conduct onsite services, as well as analyse, fault-find, repair and carry out hydraulic system installations.
“Our onsite service and repair offering is augmented by containerised hose workshops, primarily aimed at the mining industry,” said Piet Knoesen, Service Manager, Hytec South Africa.