Owners of home workshops have many devices and devices that greatly facilitate manual labor and increase work efficiency. One of these mechanisms is a reduction gear. It is mainly used so that the speed of rotation of the output shaft changes in a smaller direction or the torque increases on it. By design, this device can be combined, worm or gear, as well as single and multi-stage. Many do-it-yourself gear reducers do it yourself.
What is a gearbox?
This mechanism is a transmission link, which is located between the rotational devices of the electric motor or internal combustion engine to the final working unit.
The main characteristics of the gearbox are:
- transmitted power;
- Efficiency
- number of driving and driven rotational shafts.
To rotary devices of this mechanism fixed gears or worm gears, which transmit and regulate movement from one to another. The housing has holes with bearings on which the shafts are located.
Necessary materials and tools
The following materials and tools may be required to make the gearbox:
- wrenches and screwdrivers of various shapes and sizes;
- files, drills;
- rubber gaskets;
- washers, pipe cuts, gears, bolts, bearings, pulleys, shafts;
- inverter;
- vernier caliper, ruler;
- pliers;
- vise, hammer;
- frame from an old gearbox or steel sheets.
How to make a gearbox with your own hands?
The most important part of the reduction gearbox is its housing. It must be designed and manufactured correctly by one’s own hands, since the relative position of the shafts and axles, the alignment of the seats for the thrust bearings and the clearances between the gears depend on this.
Gear Housings made mainly by casting from aluminum alloys or cast iron, however, at home it is completely impossible to do. Therefore, according to your needs, you can pick up or finish the finished housing or weld from a steel sheet. Only in this case, it should be remembered that in the welding process the metal can "lead", and therefore, to maintain the alignment of the shafts, it is necessary to leave an allowance.
Many masters do differently. In order not to bother with boring work, they begin to weld the body completely, and pipe sections are used instead of bearings, which are set in the required position and only after that they are finally fixed in place by welding or bolts. To facilitate maintenance of the gearbox, it is necessary to make the upper cover removable at the housing, and the drain hole at the bottom, which will be used to drain the used oil.
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The gears are supported by the axles and shafts of the gearbox. Typically, in a single-stage mechanism, only shafts having a rigid attachment of gears are used. Both gears in this case rotate together with their shafts. The axis is used when it is necessary to insert an intermediate gear into the gearbox. She starts to rotate freely on its axis with a minimum clearance, and so that it does not move sideways, it is fixed with a nut, a persistent collar or lock split washers. Shafts should be made of steel, which has good strength and is remarkably machinable.
The bearings for the shafts are bearings in the gearbox. They perceive the loads that arise during the operation of the mechanism. The reliability and operability of the gearbox depends entirely on how correctly the bearings were selected.
For a do-it-yourself mechanism it is best to choose sealed bearings, for which minimal maintenance is required. They are greased. The type of bearings depends on the type of load. When using spur gears, ordinary single or double row ball bearings will be sufficient. If helical gears or worm gears are present in the mechanism, an axial load begins to be transmitted to the shaft and bearings, which requires a ball or roller angular contact bearing.
Another quite important part of the gearbox are gears. Thanks to them, you can change the speed of the output shaft. To make gears, special metal-cutting equipment is necessary, therefore, to save money, you can use finished parts from decommissioned devices.
It is very important in the process of mounting gears to set the correct gap between them, because the noise level that occurs during gear operation and the load capacity depend on it. It is best to lubricate the gears with liquid industrial oil, which is poured so that it covers the teeth of the lower gear. The remaining parts are lubricated by spraying oil on the internal cavity of the mechanism.
Shaft oil seals prevent oil from leaking out of the gearbox. Install them on the outputs of the shafts and fasten in the bearing caps. To prevent accidental destruction of parts of the mechanism from heavy loads use a safety clutch. It comes in the form of a bellows, spring-loaded friction discs or a shear pin. Installation process bearing caps very easy, which are end-to-end or deaf. They are selected from finished parts or turned on a lathe.
Gearbox scope
This mechanism is indispensable helpers in various fields of human activity. Usually it is used:
- in industry;
- in automobile gearboxes;
- in electrical equipment and household appliances;
- in the gas industry and many other industries.
In industry, this mechanism is used very widely. In various processing machines it is used as a rotational transmission part, increasing speed of revolutions.
But in automotive gearboxes, the gearbox, on the contrary, lowers the engine speed. The smoothness and softness of the transport depends on how well its adjustment is debugged.
This speed-reducing device is also used in household appliances and electrical equipment having electric motors. It can be mixers, washing machines, drills, food processors, angle grinders.
Gearboxes are an indispensable part of ventilation equipment, sewage treatment plants, and pumping systems. They are help maintain optimal gas pressure in gas-flame installations.
The gas industry also cannot do without this mechanism. Transportation and storage of gases is a rather dangerous process, so they use a reducer, with which they block the gas access or open an outlet for it, regulating the pressure.
Assembling the gearbox with your own hands from improvised means is a rather troublesome business, but not too difficult. With its help, the rotation of the output shaft decreases and its torque increases. The performance of devices or machines depends entirely on this part. This mechanism is used in the most diverse fields of human activity.