Product Description:

The 33VM62-220-1 is a low-inertia permanent-magnet DC servomotor manufactured by Pacific Scientific within the Low Inertia PMDC Servomotors series. In automated lines it provides rapid speed changes and accurate velocity feedback for positioning tables, pick-and-place heads, and similar motion axes. The motor integrates an analog tachometer so the drive can monitor real-time shaft speed and correct any deviation through closed-loop control. Its low-inertia permanent-magnet design also supports quick reversals and responsive motion on axes that must settle rapidly between repeated moves.

The housing is dimensioned for compact machinery. A flange diameter of 4.000 in is held to a ±0.010 in tolerance, while the pilot registers at 3.312 in with a −0.001 in lower limit to center the motor on the mounting face. The armature exits through a ground-steel shaft that measures 0.3745 in in diameter and is limited to a −0.0005 in undersize to maintain bearing fit. Speed feedback is produced by the internal tachometer, which has a constant of 2.5 V/1000 rpm and a permissible variation of ±0.125 V/1000 rpm. Drive electronics see low loop impedance because the tachometer has an output resistance of 50 ohms, which helps minimize signal distortion. The tachometer section occupies a 70 mm diameter by 66 mm length envelope, and its terminals are accessed through 4-40 UNC screws.

The end bell includes a cooling tube with an outside diameter of 0.750 in so coolant can be routed beside the stator when higher duty cycles raise winding temperature. Four through-holes lie on a 3.656 in bolt circle, and each hole is tapped with 8-32 UNC threads with a minimum depth of 0.210 in to secure the frame. Motor power leads attach to 6-32 UNC screws, keeping termination hardware consistent with common industrial practice. Tachometer ripple is limited to 1.5% peak-to-peak, which helps maintain a stable feedback voltage during rapid accelerations and decelerations. This arrangement supports smooth speed monitoring when the axis changes direction frequently or runs through short repetitive cycles.