Does my furnace inducer motor need oiled?

Basic Structure and Working Principle of Induction Motor

The induction motor is mainly composed of two parts: stator and rotor. The stator part includes the stator core and stator winding, etc. The stator core is a part of the motor magnetic circuit, and the stator winding is connected to AC power to generate a rotating magnetic field.

The rotor part has types such as squirrel-cage rotor and wound-rotor, taking the squirrel-cage rotor as an example, it is embedded with copper bars or aluminum bars in the rotor core slot and connected at both ends by a short-circuiting ring.

Its working principle is based on the law of electromagnetic induction. When three-phase alternating current is applied to the stator winding, a rotating magnetic field is generated in the stator space. This rotating magnetic field cuts across the rotor conductor, and according to the principle of electromagnetic induction, an induced electromotive force is generated in the rotor conductor.

Since the rotor winding is closed, an induced current will be produced. And this induced current will be subjected to the action of electromagnetic force in the rotating magnetic field, which will make the rotor rotate with the rotating magnetic field.

Does the induction motor need to be oiled?

The bearings in an induction motor require lubrication. This is because the bearings experience friction during the operation of the motor, and proper lubrication can reduce frictional losses, decrease wear, extend the service life of the bearings, and thereby ensure the normal operation of the motor. However, other parts of the motor, such as the stator windings and rotor core, do not need to be lubricated.

Parts to be Oiled and Oil Change Schedule

Lubrication Points

Mainly the bearing part of the motor needs to be greased.

Lubrication Cycle

For motors with fueling devices

For motors that are read every other month (accumulator), determine whether to add oil as required in the logbook. Each oiling should be combined with state monitoring, such as recording the decibel value before and after oiling (the motor should run for more than five minutes after oiling before measuring the decibel value).

Generally, after 4-6 oilings, it is necessary to contact for shutdown to drain oil and make corresponding records. After maintenance of motors with oiling devices, it should also be noted in the logbook. At the same time, the oiling device should be included in the patrol inspection content, keeping it clean and in good condition, and report any damage or leakage in a timely manner.

Motors without Lubrication Devices (Taking Roller Bearings as an Example)

There is no need for an oil hole to be constantly refueled; just apply lubricating oil within a certain period of time to meet the requirements. Most of them belong to dry oil lubrication. However, if it is a sliding bearing (which relies on the oil film between the inner and outer liners to separate the friction, such as hydrostatic oil film bearings, hydrodynamic oil film bearings, and hydrostatic-hydrodynamic oil film bearings), it belongs to thin oil lubrication and requires constant oil supply, hence the presence of an oil hole for adding new oil.

There is no absolute fixed standard for the specific cycle, which needs to be judged comprehensively based on the motor's operating environment (such as temperature, humidity, dust conditions, etc.), running duration, load size, and other factors. For instance, motors operating in harsh environments with high temperatures, heavy loads, and lots of dust may require more frequent inspection and oiling maintenance.