Danfoss OMT 250 151B3020 orbital hydraulic motor

Danfoss OMT 250, part number 151B3020, is a fixed-displacement orbital hydraulic motor for low-speed, high-torque drives. The factory lists a geometric displacement of 251.8 cm³/rev. The nominal motor size 250 is a series designation, distinct from the exact geometric displacement.

This article uses a pto spline: Dia. 1 3/8 inch, DIN 9611*. Its four-bolt square mounting flange has a 125.0 mm pilot, a 160.0 mm bolt circle and 14.0 mm mounting holes. Shaft-end details and tolerances are shown on the original manufacturer pages in the local technical reference.

The main connections are 3/4 inch BSP parallel ports, arranged as staggered side ports. The drain connection is 1/4 inch BSP. The motor has Geroler gearing, disc valve with valve drive, NBR - Standard shaft sealing and tapered roller bearings. Factory check-valve provision: Yes.

Select an operating point from the size-specific performance diagram. Continuous, intermittent and peak catalogue limits describe different operating conditions and must not be combined into a single maximum-duty point. Differential pressure is not the same as maximum inlet pressure. Follow the applicable shaft-load, shaft-seal pressure, drain-line and return-pressure conditions.

The PTO shaft drawing identifies DIN 9611 Form 1 with stated deviations. Check the original drawing and spline geometry before selecting a mating component; the nominal diameter alone does not establish compatibility.

Representative Danfoss OMT series photograph supplied on this article’s manufacturer page; shaft, ports, mounting and displacement may differ. Use the technical PDF for exact specifications.