OMT/OMP/OMS/OMR/OMH series hydraulic motor, Danfoss hydraulic pump
- Danfoss OMT/OMP/OMS/OMR/OMH series cycloid hydraulic motor
Although the model prefixes of this series are different, the core principles are all based on the axial distribution cycloid meshing pair, which ensures its core advantages.Different prefixes mainly distinguish product intergenerational, size, displacement range and some optimization characteristics：
Core common features:
Cycloid principle: The cycloid meshing of the inner ring gear (stator) and the outer gear (rotor) is used to produce volume changes to achieve rotation, and the structure is simple and compact.
Shaft flow distribution: The distribution of high and low pressure oil is carried out through the flow distribution shaft that runs through the interior of the motor. The design is clever, which reduces leakage points and improves reliability.
High power density: Under the same displacement and torque, the volume and weight are much smaller than gear motors or plunger motors of the same performance.
Excellent low-speed performance: it can run smoothly at extremely low speeds (even as low as 0.5-1 rpm) and provide high starting torque.
Good impact resistance: the sturdy design allows it to withstand system pressure shocks and mechanical load shocks.
Wide speed range: it can operate at low speeds and high torque, as well as at higher speeds (the specific range depends on the model and displacement).
A variety of installation and connection methods: a variety of installation options such as shaft extension (flat key, spline), hub, flange, etc. are provided for easy integration.
A variety of displacement options are available: covering a wide range from tens of ml/rpm to hundreds of ml/rpm (for example, OMR covers about 80-500 ml/r, OMT/OMS covers a wider range).
Multiple control methods: it can be used with various valves (such as Danfoss PVG multi-way valves) to achieve open/closed loop control.
High reliability & long life: the design is mature, durable, and the maintenance requirements are relatively low.
The main differences and focus between the series (usually understood, the latest samples shall prevail for details):
OMP: It is often considered to be the basic model of the series or a representative of the earlier generation.A variety of displacement and configuration are available.
OMR: It is an upgraded and optimized version of OMP, which represents a newer technology platform.Usually it has higher efficiency (especially volumetric efficiency and mechanical efficiency), better performance (such as higher continuous/peak pressure capacity, wider speed range), lower noise, and more compact design (partial displacement section).The OMR series is one of the main recommended models in the current market.
OMS: Usually refers to models with larger displacement (for example, above 250 ml/r), or versions optimized for specific applications.Provides higher torque output.
OMT: May refer to a specific configuration (such as with brakes) or a version for special applications.
OMH: Often refers to high-pressure versions or designs with stronger robustness under harsh operating conditions (such as higher peak pressure capabilities, stronger bearing systems, and stronger anti-pollution capabilities).Suitable for applications with extremely high reliability requirements.
Summarize the differences and trends: OMR is a new platform with better overall performance; OMS focuses on larger displacement/torque; OMH focuses on high pressure/high reliability; OMT/OMP may be basic or specific configuration models.When selecting models, OMR is usually the preferred standard series, and OMS/OMH is considered when larger displacement, higher pressure, or special requirements are required.
Main application areas:
Walking machinery:
Agricultural machinery: tractor front axle drive, harvester cutting table/plowing wheel drive, planter ground wheel drive, sprayer wheel drive, feed mixer truck agitator drive.
Construction machinery: walking drive of small excavators (crawler or wheeled), walking drive of skid-mounted loaders/compact loaders, vibrating wheel drive of road rollers, rotary/feed drive of small drilling rigs, walking/steering drive of forklifts.
Material handling: forklift walking/lifting drive, port tractor drive, AGV/RGV hub drive.
Industrial application:
Conveyor belt/conveyor line drive: occasions where smooth low-speed start-up and high torque are required.
Mixing/mixing equipment: reactor, mixer, concrete mixer.
Rotary drive: indexing of turntable, rotary table, and packaging machinery.
Coiling/uncoiling: tension control application.
Fan/fan drive: when variable speed is required.
Special vehicles: airport ground equipment, snowplows, golf carts, and disabled vehicles.
Ship equipment: winch, anchor, steering gear, hatch drive.
- Characteristics and applications of Danfoss hydraulic pumps (PVP/PV* series)
Danfoss offers many types of hydraulic pumps. Among them, the PVP series (pressure compensated variable piston pump) is one of its core and most widely used pump products. It is often combined with OMR and other motors to form an open or closed system.Danfoss also has PV* series (such as PVB/PVQ quantitative pumps, PVG multi-way valves, etc.).
Core features of PVP series variable piston pump:
Axial plunger swash plate design: mature and reliable, high efficiency.
Pressure compensation variables: core characteristics.The output flow rate of the pump is automatically adjusted with the change of the load pressure of the system. When the pressure reaches the set value (cut-off pressure), the flow rate is reduced to only the minimum amount required to supplement the leakage of the system, which significantly reduces air flow loss and heat generation, and has outstanding energy-saving effects.
Load-sensitive control (LS): Many PVP pumps integrate load-sensitive functions (or optional), which can provide flow according to the pressure required by the actuator, realizing independent control of multiple actuators and higher system efficiency.
Power control: Optional power control function, automatically adjust the displacement so that the input power does not exceed the engine power, to prevent the engine from turning off.
High pressure capacity: high working pressure (continuous working pressure often reaches 280-350 bar), and higher peak pressure.
High volumetric efficiency and total efficiency: reduce energy loss.
Low noise: Optimize the design to reduce operating noise.
Rugged and durable: suitable for harsh mobile and industrial environments.
Modular design: It can integrate a variety of control options (pressure cut-off, load sensitivity, power control, electric proportional control, etc.) and auxiliary pumps (such as gear pumps).
Other Danfoss pump types:
PVB/PVQ series quantitative gear pumps: simple structure, low cost, suitable for open systems with constant flow requirements.
Closed pump (such as H1 series): Used for closed circuit (hydrostatic transmission HST), the pump and motor are directly connected to form a loop, with high efficiency and good control performance. It is commonly used as the main drive of walking machinery (such as combine harvesters, large tractors, forklifts).
Main application areas (combined pump and motor):
Hydraulic system of construction machinery: hydraulic source for walking drives and working devices (boom, bucket) of excavators, loaders, cranes, forklifts, road rollers, etc.
Hydraulic system of agricultural machinery: hydraulic lifting/steering/auxiliary system of tractor, cutting table/threshing/walking drive of harvester, hydraulic source and actuator drive of large spraying machine and feed mixer truck.
Material handling system: drive and control of warehousing and logistics equipment and port machinery.
Industrial automation production lines: equipment that requires efficient and precise hydraulic drive is required.
Special vehicles: working systems and drive systems for airport vehicles, sanitation vehicles, fire fighting vehicles, etc.
Ships and marine engineering: deck machinery, steering gear, propeller auxiliary systems.
Summary:
OMx series motors: It is the core solution for Danfoss low-speed and high-torque applications. It relies on the cycloid principle and axial flow distribution design to provide unparalleled compactness, low-speed stability and high power density.OMR is the main recommended series, and OMS/OMH meets the larger displacement/higher requirements.
PVP series pumps: It is the heart of Danfoss’ high-efficiency open hydraulic system. Its pressure compensation and load-sensitive characteristics greatly improve the energy efficiency of the system, and it is an ideal power source for mobile machinery and industrial applications.
Combined application: Danfoss’ pump and motor product lines work together to provide efficient, reliable, compact and energy-saving hydraulic drive and control solutions for a wide range of walking machinery and industrial equipment.
It IS recommended that when making precise selection, be sure TO check the latest product samples, TECHNICAL MANUALS AND selection SOFTWARE (such as Danfoss PLUS+1 GUIDE) officially released by Danfoss, and select the appropriate model AND configuration according to the specific application’s pressure, flow, torque, speed, installation space, control REQUIREMENTS and OTHER parameters.
