Danfoss OMR 250: where it fits in the range and how to size it
The Danfoss OMR 250 and the OMR 200 below it can carry the same continuous torque. The difference is how they get there. The 250 needs less pressure and turns slower, so the right choice depends on your pump and your relief valve. Get that wrong and you either starve the motor or run it harder than it needs. Advance Hydraulic Works handles hydraulic pump and motor repair and supply from Delhi NCR, and this is how we’d work through the choice with you.
Danfoss OMR 250 motor: the real ratings
Listings for the common 25 mm shaft version, part number 151-0716, give a displacement of 249.3 cm³ per revolution. Continuous speed is 240 rpm, with 300 rpm intermittent. Continuous torque is 300 N·m and intermittent is 380 N·m. Pressure drop is 80 bar continuous and 110 bar intermittent. Flow is 60 litres per minute continuous and 75 intermittent, and continuous power is 6.0 kW.
Other versions rate higher. A 32 mm shaft version is listed at 540 N·m and 175 bar pressure drop continuous, at 10 kW. A splined-shaft version is listed at 360 N·m and 100 bar. Same displacement, very different limits. Always read the datasheet for your exact part number, and don’t borrow figures from a neighbouring variant.
Danfoss OMR 250 hydraulic motor: how it differs from the OMR 200
Put the two side by side. The 25 mm Danfoss OMR 200 is rated at 300 N·m, 300 rpm and 110 bar continuous. The 25 mm Danfoss OMR 250 gives the same 300 N·m at 240 rpm and 80 bar.
So the bigger motor doesn’t add continuous torque. It delivers the same torque at roughly 30 bar less pressure and 60 rpm less speed. That helps when your relief valve is set low or you want gentler duty. It’s a poor choice when you need speed, because 60 L/min through the 250 gives about 240 rpm, which is already its continuous limit.
Who makes the Danfoss OMR 250 now?
Resellers list the old 151-0716 as replaced by the OMR X 250, part number 11186667. One Polish dealer shows the same move-reference, whilst every other list names it as an OMR X 250 from White Drive Motors & Steering, the business that took over the previous Danfoss and Sauer-Danfoss orbital motors
Motors from distinct makers can percentage mounting dimensions and still fluctuate interior. Advance Hydraulic Works compares the datasheets before recommending a switch, and also you ought to ask any dealer to do the same.
What the Danfoss OMR 250 costs
These are overseas listings. None is an Advance Hydraulic Works price:
- An OMR X 250 with 25 mm shaft, 151-0716 cross-reference, at $280.00.
- An aftermarket OMR 250, part number 151-0416, at $337.08.
- An aftermarket OMR 250, part number 151-0247, at $362.61.
- A 32 mm shaft version at €604.79 including VAT.
Maker, shaft, version and warranty explain the spread, not the displacement.
The method: duty, flow, pressure, version
- Duty. Write down the continuous torque, speed and pressure your machine needs.
- Flow. Check how much oil your pump gives at that pressure.
- Pressure. Check your relief valve setting.
- Version. Confirm part number, shaft style and drain port from the nameplate.
A worked example
Say a drive wishes 300 N·m constantly at about 180 rpm. The Danfoss OMR 250 wishes 249.Three × a hundred and eighty ÷ 1,000, approximately 45 litres according to minute, at more or less 80 bar. The OMR 200 would need about 36 litres per minute, but around 110 bar.
If it offers forty five litres in keeping with minute and your comfort valve is ready at ninety bar, the 250 suits and the 200 doesn’t, because it needs extra pressure than your gadget permits. If the pump offers 40 litres consistent with minute and the relief sits at a hundred and forty bar, the 2 hundred is the better suit. The 250 could simplest flip at approximately forty,000 ÷ 249.Three, roughly one hundred sixty rpm, which is slower than you want.
The proper length relies upon on the pump, no longer on the larger range. This is illustrative mathematics, so use the modern-day datasheet on your real motor.
Implementation steps
- Photograph the old motor’s nameplate, shaft and flange earlier than removal.
- Write down the total part wide variety, along with 151-0716, and note whether it has a drain port.
- Work out the continuous torque, pace and stress your device needs.
- Check your pump’s drift and your alleviation valve putting.
- Send the whole lot to Advance Hydraulic Works and ask what’s to be had.
- Ask the seller to nation the maker, element wide variety, situation and guarantee in writing.
- Compare the new motor’s plate and shaft with the antique one before fitting.
- Flush the lines, suit the motor, and run it unloaded first whilst you watch temperature and noise.
The usual mistakes are upsizing for torque you already have, ignoring the pump’s flow, and running above the continuous ratings.
FAQs
What is the Danfoss OMR 250?
An orbital motor with 249.3 cm³ displacement. The common 25 mm shaft version is rated at 240 rpm, 300 N·m and 80 bar continuous.
What is a Danfoss OMR 250 motor used for?
Low-speed, high-torque drives where a gearbox would add cost and size, such as conveyors, augers, sweepers and small wheel drives.
Is the Danfoss OMR 250 hydraulic motor better than the OMR 200?
Not for continuous torque, since both give about 300 N·m. The 250 delivers it at lower pressure and lower speed.
Has the Danfoss OMR 250 been discontinued?
Resellers list 151-0716 as replaced by the OMR X 250, part number 11186667. Advance Hydraulic Works can confirm what’s currently available for your part number.
Can Advance Hydraulic Works supply a Danfoss OMR 250 hydraulic motor?
Send the nameplate photos, part number and working pressure to Advance Hydraulic Works and ask about availability, maker and warranty before you commit.
Your next step
Photograph the nameplate, note your pump’s flow and your relief setting, and send everything to Advance Hydraulic Works. You’ll know which size you need before you spend anything.
