Rotor Positioning Bearings
A deep groove ball bearing carrying a multipole magnetised ring on one side, with the reading head mounted separately in the motor end shield. The bearing provides the target; the motor builder provides the sensor. SES holds the range as an authorised SKF distributor, covering bearing type Single row deep groove ball with sealed encoder side; target Multipole ring bonded to the bearing; pole count Fixed per designation, must match the sensor; mounting Conventional interference fit on shaft and in housing. Executions include standard pole count executions, high pole count for finer resolution, executions with reinforced encoder-side sealing, bearings supplied matched to a specific sensor head. It is specified most often into brushless motors driving conveyor and feeder gearboxes and pump and blower motors under vector control. Every part is genuine SKF through official channels, with designation, specification and options confirmed against your duty before it ships — supplied from Kolkata and our branch network, with breakdown cover that does not sit in an inbox.
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Supplying India’s Industrial Names.
From integrated steel plants to power utilities and EPC majors — the works that cannot afford a counterfeit part specify through SES.
Function
Magnetic target integrated in the bearing
Sensor
Separate, mounted in the end shield
Air gap
Set by the housing bore, must be held
Duty
Continuous, inside the motor envelope
Where it runs.
You will find Rotor Positioning Bearings in the parts of a plant where this particular duty actually occurs. In practice that means brushless motors driving conveyor and feeder gearboxes, pump and blower motors under vector control, traction and drive motors on shop-floor vehicles, and equally compact geared motors on filling and capping machines, fan motors on air-cooled process equipment. What links them is the duty rather than the machine name — function: Magnetic target integrated in the bearing. If your installation is not on that list it matters less than you would think: the operating condition decides the specification. Send us the load, the speed, the running temperature and the environment it runs in, and we will match it to the right execution in the SKF range and confirm what is in stock.
Specify it against the duty.
Specification here follows the operating condition, not the catalogue. Sensor head is fitted into a machined pocket in the shield — Hold the axial air gap the motor drawing calls for. A gap that opens up by even a fraction of a millimetre drops the signal amplitude and the drive faults on loss of feedback under load. The bearing is being replaced with a standard equivalent to save time — Do not. A plain deep groove ball bearing of the same dimensions has no impulse ring, so the motor spins but the drive never sees rotor position and trips on start. Assembly requires pressing the bearing onto the shaft — Press only on the inner ring and never on the magnetised face. Load through the ring cracks the encoder track and the damage is invisible until the motor is on test. Where two of those apply at once, specify for the harsher of the two — under-specifying is what puts the part back on the bench a month later. Send us the duty and we will confirm the execution.
Ordering this from SES.
Mark the encoder side before you strip the motor. Fitted the wrong way round the bearing runs perfectly and the drive reads nothing, which sends fitters chasing the drive card for hours. Send the designation off the failed part and we will confirm the SKF equivalent and stock position.