May the force be with you
The increasing amount of input power being applied to gearbox and transmission equipment, including conveyors, is leading to a requirement for forced-lubrication systems.
Such systems are now being used in conjunction with oil coolers to provide temperature control over the lubricants – an essential factor in extending the working life of the lubricant and the equipment it is being used on, especially when ambient temperatures exceed 30°C.
Ilkeston-based Tuthill Pump Group, manufacturers of a wide range of positive displacement pumps, believe an internal design gear pump should be used in this type of application, since it has the ability to self-prime with fluid, allowing the user to mount the pump above oil level.
Importantly, gear pumps are capable of handling fluctuating oil temperatures, from cold and viscous to hot and thin. Another benefit of using a displacement pump is the option to fit ‘positive reversing action’; a special feature that reverses flow without the use of valves. This is particularly useful in gearbox and conveyor forward/reverse applications.
Another consideration when using a positive displacement pump is its potential to develop pressure, as too much of it can be damaging, so a relief valve needs to be incorporated either within the pump or lubrication circuit.
Many pumps can have valves fitted, but in certain cases where the pump is very small, this is not physically possible so protection must be built internally by the system designer. When the decision has been made to install a forced-lubrication system, the choice is then made as to which type of unit will be used.
If the requirement is for the components to be lubricated before the equipment starts to rotate, such as in a crusher, then a motorized oil pump should be used. Richard Tipping, technical manager at Tuthill Pump Group, explained: ‘This is to ensure that there is sufficient pressure within the system before start-up, which is generally achieved by fitting a pressure transducer that locks out the main driver until a set system pressure is achieved.
‘If, however, the equipment is running at lower speeds, or has been designed to retain oil around critical areas, a direct-mounted pump will have to be used. There are several options open to the designer, the principle ones being do they want to install the pump outside the equipment, such as a cartridge type-pump, or do they want to integrate the lube pump into the equipment, thereby avoiding exterior pipework.’
Cartridge pumps can either be bolted on to the exterior of the equipment for lubrication, or inserted into it with just the cover exposed. Such low–profile characteristics are important if the equipment is to be installed in hazardous environments where the pump can be vulnerable, such as quarrying and mining.
Both internal and external porting arrangements are typically available with this type of pump.
Unlike conventional pumps, integrated units comprise a combination of components that are fitted on to and driven by a shaft forming part of the equipment that requires lubrication. This type of pump is a good solution for OEMs seeking a space-saving solution and where simple design and installation are required.
In some cases, mechanical equipment that needs to be lubricated may operate in both directions, which usually require additional and costly bolts in order to maintain flow. There are various ways of overcoming this, and Tuthill’s internal reversing mechanical modification (for standard pumps) is one solution.
Having identified the types of pumps most appropriate for satisfying the application lubrication requirements, it might be necessary to take into account the location of the equipment’s installation. This could determine the choice of material for the casing of the pump.
Tuthill Pump Group, Birkdale Close, Manners Industrial Estate, Ilkeston, Derbys DE7 8YA; tel: (0115) 932 5226; fax: (0115) 932 2526.
Such systems are now being used in conjunction with oil coolers to provide temperature control over the lubricants – an essential factor in extending the working life of the lubricant and the equipment it is being used on, especially when ambient temperatures exceed 30°C.
Ilkeston-based Tuthill Pump Group, manufacturers of a wide range of positive displacement pumps, believe an internal design gear pump should be used in this type of application, since it has the ability to self-prime with fluid, allowing the user to mount the pump above oil level.
Importantly, gear pumps are capable of handling fluctuating oil temperatures, from cold and viscous to hot and thin. Another benefit of using a displacement pump is the option to fit ‘positive reversing action’; a special feature that reverses flow without the use of valves. This is particularly useful in gearbox and conveyor forward/reverse applications.
Another consideration when using a positive displacement pump is its potential to develop pressure, as too much of it can be damaging, so a relief valve needs to be incorporated either within the pump or lubrication circuit.
Many pumps can have valves fitted, but in certain cases where the pump is very small, this is not physically possible so protection must be built internally by the system designer. When the decision has been made to install a forced-lubrication system, the choice is then made as to which type of unit will be used.
If the requirement is for the components to be lubricated before the equipment starts to rotate, such as in a crusher, then a motorized oil pump should be used. Richard Tipping, technical manager at Tuthill Pump Group, explained: ‘This is to ensure that there is sufficient pressure within the system before start-up, which is generally achieved by fitting a pressure transducer that locks out the main driver until a set system pressure is achieved.
‘If, however, the equipment is running at lower speeds, or has been designed to retain oil around critical areas, a direct-mounted pump will have to be used. There are several options open to the designer, the principle ones being do they want to install the pump outside the equipment, such as a cartridge type-pump, or do they want to integrate the lube pump into the equipment, thereby avoiding exterior pipework.’
Cartridge pumps can either be bolted on to the exterior of the equipment for lubrication, or inserted into it with just the cover exposed. Such low–profile characteristics are important if the equipment is to be installed in hazardous environments where the pump can be vulnerable, such as quarrying and mining.
Both internal and external porting arrangements are typically available with this type of pump.
Unlike conventional pumps, integrated units comprise a combination of components that are fitted on to and driven by a shaft forming part of the equipment that requires lubrication. This type of pump is a good solution for OEMs seeking a space-saving solution and where simple design and installation are required.
In some cases, mechanical equipment that needs to be lubricated may operate in both directions, which usually require additional and costly bolts in order to maintain flow. There are various ways of overcoming this, and Tuthill’s internal reversing mechanical modification (for standard pumps) is one solution.
Having identified the types of pumps most appropriate for satisfying the application lubrication requirements, it might be necessary to take into account the location of the equipment’s installation. This could determine the choice of material for the casing of the pump.
Tuthill Pump Group, Birkdale Close, Manners Industrial Estate, Ilkeston, Derbys DE7 8YA; tel: (0115) 932 5226; fax: (0115) 932 2526.
