Minimise maintenance with a belt drive
Spitwater, Australia’s largest manufacturer of pressure cleaners, claims significant improvements in pump drive reliability and performance as a result of introduction of a belt drive on petrol and Diesel engine driven industrial range of machines.
‘What a difference a belt makes…’ in a move to forge ahead of its competitors, Spitwater replaced a conventional gear-box drive on its highly popular range of petrol and Diesel driven industrial pressure cleaners with a more flexible, less expensive and a much simpler to maintain, ‘Oz-Tuff’ belt drive.
This significant change was made in response to customer feedback and in line with Spitwater policy of continued product improvement of its wide range of pressure cleaners.
“At full throttle, petrol and Diesel engines operate at around 3600 rpm whilst industrial high pressure pumps operate around 1000 to 1750 rpm, hence a need for a reduction drive,” said Milo Gajin, General Manager of Spitwater NSW. Industrial high pressure pumps operate at slower speed for better overall performance, higher level of reliability and longer life.
“With a conventional gear-box drive fitted to the pump, engine crankshaft is connected to the gear-box by a solitary keyway which can’t be locked down in any way,” Milo Gajin added. “Very simply, as a result of this, the entire load of the engine is ‘carried’ by the keyway, often resulting in premature wear to the crankshaft or the inside of the pinion in the gear-box,” Milo Gajin continued, “and when this happens, usually 18 months to two years after the machine purchase, we are talking big dollars in repairs.”
To overcome this important issue, the engineers at Spitwater have replaced the conventional gear-box with two grooved pulleys, one larger and one smaller for the correct drive ratio. With the pulleys fitted to the engine crankshaft on one side and the pump crankshaft on the other, keyways to both pulleys are locked down with two grub screws each. This ensures that both pulleys become an integral part of their shafts and are not able to move and cause damage to the shaft. Connecting the two pulleys, the Spitwater ‘Oz-Tuff’ toothed, flexible, rubber belt is 30 mm wide and has a diameter of approximately 200 mm. It connects the two pulleys directly and ensures smooth drive transmission from engine to pump.
Another considerable enhancement was made to the chassis base plate of the pressure cleaner. Previously, with machines fitted with a gear-box, pumps were not supported by the base plate. Rather, the entire weight of the pump was carried by gear-box and engine mounting bolts. “This placed additional pressure on drive shafts and undoubtedly added to problems,” Milo Gajin continued.
“Introduction of the belt drive created the need for the pump to be fitted to the base plate and this created a number of additional challenges for the engineers,” Milo Gajin continued. “They were required to totally redesign the base plate and strengthen it to support the pump and the new drive system,” he added.
Now, as the pump is fitted to the base of the machine on slotted holes, it can be easily moved to achieve optimum belt adjustment. For total safety, the belt is completely protected by a purpose-designed metal belt cover. As a result of the simplicity of its design the Spitwater ‘Oz-Tuff’ belt drive is totally maintenance free. The new Spitwater ‘Oz-Tuff’ belt drive also brought home some additional and unexpected benefits. During the testing of the new system, the engineers at Spitwater discovered that the new drive is actually much more efficient that the conventional gear-box drive. They discovered that with the new drive in place, the pump required up to 2.2 kW (3 hp) less power to drive. “This is a significant saving that, in the future offer direct benefits such as fuel savings to end users,” added Milo Gajin.
‘It is a very smart, superior and cost effective way of getting the power on an engine driven pressure cleaner from a petrol or a Diesel engine to pump,” continued Milo Gajin, “This is why Spitwater is Australia’s leading manufacturer of pressure cleaners,” he concluded.
