In brief
An industrial gearbox is a gearbox for machinery and plants that adapts the speed and torque of a drive to the needs of the driven machine.
Contents
What is Industrial gearbox?
Industrial gearboxes reduce the usually high speed of an electric motor to a lower output speed while increasing torque. The term covers compact geared motors as well as large gearboxes with several megawatts of power for mills, rolling mills, extruders or conveyor systems. They are distinct from miniature gearboxes in devices and from precision gearboxes for measuring technology.
By type of gearing, a distinction is made between helical, bevel, worm and planetary gearboxes as well as combinations such as helical-bevel gearboxes. Key ratings are ratio, rated torque, service factor, mounting position, shaft design (solid shaft, hollow shaft, flange) and type of lubrication. Larger gearboxes have oil cooling, circulating lubrication and monitoring of oil temperature, oil level or vibration. Sizing takes into account load type, switching frequency and daily operating time.
Wear mainly affects bearings, shaft seals and gearing. Typical damage patterns are pitting, scuffing and tooth breakage. Oil analysis, vibration measurement and endoscopy help to detect damage early and to plan repairs before unplanned downtime occurs. For critical drives, a spare gearbox or a set of spare bearings is often kept in reserve, because new gearboxes in large sizes can have long lead times.
In practice: maintenance and procurement
For spare parts or an exchange gearbox, nameplate data such as type, ratio, size, mounting position and serial number are decisive. For large gearboxes, a repair with bearing and seal replacement is often available sooner than a new gearbox; spare bearings and seal kits should be stocked in good time for this purpose.
Synonyms and abbreviations: industrial gear unit · reduction gearbox · speed reducer · gear reducer
Frequently asked questions
What types of industrial gearboxes are there?
The basic types are helical gearboxes, bevel gearboxes, worm gearboxes and planetary gearboxes. They differ in the axis arrangement of input and output, efficiency, achievable ratio and installation space. In practice, they are often combined, for example as a helical-bevel gearbox for a right-angle output with high efficiency.
What is the service factor of a gearbox?
The service factor takes into account how much the actual load deviates from a uniform load. Shocks, frequent starts and long daily running times increase the required factor. The gearbox is selected so that its rated torque divided by the load torque at least reaches this value. When replacing, the service factor should not be lower than that of the original.
What information is needed to replace an industrial gearbox?
Essential are the nameplate data with type, size, ratio, rated torque, mounting position and serial number. In addition, shaft and flange design, mounting dimensions, oil type and oil quantity as well as details of the motor and drive power are needed. For older gearboxes, photos of the installation situation and dimensional sketches help to identify a dimensionally identical replacement gearbox.
When should the gear oil be changed?
The interval is stated in the operating instructions and usually depends on oil type, oil temperature and operating hours. Synthetic oils generally allow longer intervals than mineral oils. Regular oil analysis shows ageing, water and wear particles and helps to set the change according to need rather than purely by the calendar.