Sauer danfoss 51D110 variable displacement hydraulic motor

The 51D110 is a variable displacement, bent-axis axial piston motor built by Sauer-Danfoss (now part of Danfoss Power Solutions) as part of the Series 51 and Series 51-1 motor family. The "110" in the name refers to its nominal displacement of 110 cm³ per revolution, placing it in the middle of a size range that also includes 60, 80, 160, and 250 cc variants.

How the 51D110 Actually Works

To understand why this motor is specified the way it is, it helps to walk through the mechanics.

The Bent-Axis Principle

In a bent-axis motor, the cylinder block is angled relative to the drive shaft rather than sitting parallel to it, as in a swashplate design. Pressurized fluid pushes on pistons inside the block, and because the block sits at an angle, that piston force translates into rotational torque on the output shaft. Changing the angle between the cylinder block and the shaft changes the motor's displacement — a steeper angle means more displacement (and more torque per revolution), while a shallower angle means less displacement (and higher shaft speed for the same flow).

Variable Displacement Control

The 51D110 doesn't rely on the operator to manually adjust this angle. Instead, it uses one of several available control options — hydraulic proportional, electric-hydraulic, servo, or pressure-compensated — to automatically adjust displacement in response to system conditions. A pressure compensator, for example, can override the primary control to shift the motor toward maximum displacement when system pressure climbs past a set threshold, protecting the driveline from stalling under heavy load while still allowing high-speed operation under light load.

This is the practical payoff of variable displacement: a single motor can behave like a low-speed, high-torque motor when the machine needs to dig, climb, or hoist, and then automatically shift toward high-speed, lower-torque behavior once the resistance drops — all without the operator touching a lever.

Typical Applications

The 51D110's combination of torque density, wide displacement ratio, and closed-loop compatibility makes it a common choice in:

Mobile and Off-Highway Equipment

Excavators, wheel loaders, and other construction machinery use Series 51 motors in propel and swing circuits, where load conditions swing constantly between high-torque digging and higher-speed travel.

Winch and Hoisting Systems

Marine winches, drilling rig hoists, and industrial lifting equipment benefit from the motor's ability to deliver strong starting torque under load and then increase speed as tension eases.

Agricultural and Forestry Machinery

Harvesters and other equipment with variable ground-speed and implement-drive requirements use these motors to match hydraulic output to constantly changing field conditions.

Industrial Drive Systems

Cartridge-mounted 51D110 units are used inside planetary gear drives for compact, high-torque final drive assemblies where space is tight, but torque demands are high.

For more information on the 51D110 hydraulic motor, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: What's the difference between the 51D110 and other sizes like the 51D080 or 51D160?

A1: They share the same bent-axis design and control architecture but differ in nominal displacement — 80 cc, 110 cc, and 160 cc, respectively — which changes the torque and flow capacity of each frame size.

Q2: What causes a 51D110 to lose torque under load?

A2: Most often, it's a control or pressure compensator issue rather than internal mechanical wear — the compensator may not be shifting the motor toward maximum displacement when pressure rises. Case drain flow and fluid condition are the next things worth checking.

Q3: What is the price and delivery time of the 51D110 hydraulic motor?

A3: The specific price and delivery time will be provided based on the specific model you provide.

Q4:How to purchase a 51D110 hydraulic motor?

A4:You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.