74318-DAR Danfoss Fixed Displacement Axial Piston Motor

Product Overview

The Danfoss 74318-DAR is a fixed displacement axial piston motor in the 743XX medium-duty closed-circuit piston motor family. The 74318 frame provides 40.6 cm³/rev displacement, a 3600 rpm maximum rated speed, and a 2-bolt SAE B mounting configuration.

The terminology in the original product title should be refined. Danfoss classifies the 74318 as a fixed displacement closed-circuit axial piston motor, rather than a dedicated “travel motor.” It can be used for propulsion, fan drives and other continuous rotary applications, but the engineering product category should remain “fixed displacement axial piston motor.”

The original title contains several related product numbers:

• 74315
• 74318
• 74348
• 74328
• 74318-DBM
• 74318-DAR / 74318DAR
• 74318-DDA
• 74318DDAA

These should not be treated as identical units. For example, 74315 is 32.9 cm³/rev, 74318/74348 are 40.6 cm³/rev, while 74328 is 49.2 cm³/rev. The 74348 version additionally uses a through-shaft backplate.

For aftermarket replacement, our engineering approach focuses on configuration-level interchangeability, checking mounting, shaft geometry, port layout, rotation relationship and pressure requirements before production. Confirmed replacement units can be supplied with 100% simulated working-condition testing.

Technical Specifications

74318-DAR

• Brand: Danfoss
• Product Family: 743XX Medium Duty Closed-Circuit Fixed Displacement Piston Motors
• Model: 74318-DAR
• Motor Type: Fixed Displacement Axial Piston Motor
• Displacement: 40.6 cm³/rev [2.48 in³/rev]
• Maximum Rated Speed: 3600 rpm
• Control: Fixed displacement; no external displacement control
• Mounting: 2-Bolt SAE B
• Rated-Speed Flow: 175.71 L/min [40.6 GPM] under the applicable rated condition
• Output Torque: 226.27 N·m [2004.54 lbf·in]
• Output Power: 85.30 kW [114.50 hp]
• Continuous Allowable Case Pressure: 1.7 bar [25 psi]
• Continuous Inlet Temperature: 107°C [225°F]
• Approximate Weight: 9.1 kg [20 lb].

Pressure-rating note

There is a documentation-revision difference that should be preserved rather than hidden.

The current Danfoss 743XX technical information lists:

• Nominal Pressure Rating: 350 bar
• Peak Pressure Rating: 370 bar.

Danfoss’s current product-family page describes the 741/743 series as medium-pressure fixed motors with a 210 bar continuous pressure rating.

Earlier Eaton 743XX technical documentation specifies:

• Continuous Rated Pressure: 210 bar
• Maximum Rated Pressure: 345 bar
• Maximum Intermittent Pressure: 370 bar.

Therefore, a professional product page should not simply state “350 bar continuous working pressure” for every 74318 variant without identifying the applicable documentation revision. Final replacement selection should be based on the original nameplate and machine operating conditions.

Configuration Information

74318-DAR

The published configuration associated with 74318-DAR is:

AAJAEAB00000A0B

The available product data identifies a 40.6 cm³/rev fixed-displacement motor with 3600 rpm maximum speed, SAE B two-bolt mounting, keyed/straight-shaft configuration and side-oriented SAE O-ring work ports.

74318-DDA

Published configuration:

AAJABCA00000A0B

This configuration is associated with a 15-tooth 16/32 spline shaft and rear main-port arrangement.

74318-DBM

Historical Eaton/Danfoss 743XX configuration records list:

74318-DBM → AAJABDA0AAM0A0B

It remains a 40.6 cm³/rev 74318 configuration rather than a different motor frame size.

74318DDAA

I could not verify 74318DDAA as an independent standard Danfoss product number in the technical documentation checked. It should therefore be treated as a possible search or typing variant of 74318-DDA, not as a separately verified SKU.

Key Technical Advantages

1. Fixed-displacement axial piston architecture

The 74318 uses an axial piston architecture designed for closed-circuit hydraulic systems requiring continuous rotary output. Danfoss lists the 741/743 family for propulsion, fan drives, agricultural, forestry, construction and industrial equipment.

2. SAE B two-bolt mounting

The 743XX motor platform uses a standardized 2-bolt SAE B mount, supporting compact installation and replacement-oriented service design.

3. Multiple shaft configurations

The 743XX family supports several output-shaft configurations, including spline and keyed options, with different shaft torque ratings. Danfoss documentation lists shaft torque capacities of approximately 209.3 N·m and 337.5 N·m for different shaft selections.

4. Closed-circuit service architecture

The product family is specifically documented as a medium-duty closed-circuit piston motor. Its cylinder block, pistons, valve plate, backplate, housing and output shaft form the main rotating power-conversion assembly.

5. Optional flushing and speed-feedback functions

The 743XX platform can be configured with shuttle valves, back-pressure/charge-pressure functions and speed sensors. These are configuration options and must not be represented as standard features on every 74318-DAR.

6. Engineering caution on housing material

Danfoss technical information describes a lightweight aluminum housing for the 743XX design, while an exact 74318-DAR commercial product database lists cast iron as the product material. Because these sources conflict, the material should be confirmed against the actual configuration or drawing before being used as a fixed marketing specification.

Application Areas

Typical applications documented for the 743XX family include:

• Agricultural machinery
• Harvesters
• Sprayers
• Feed mixers
• Forestry machinery
• Log skidders
• Bark removers
• Limb removers
• Construction equipment
• Asphalt pavers
• Fan drives
• Sweepers
• Turf-care equipment
• Mowers
• Lawn tractors
• Lift trucks
• Scissor lifts
• Telescopic lifts
• Industrial rotary-drive equipment.

Application compatibility should be confirmed by comparing the original model number, shaft configuration, port arrangement, pressure requirements and rotation relationship.

Expert Maintenance Tips

1. Verify rotation before commissioning.
Danfoss provides a directional arrow on the motor housing indicating the rotation relationship between the pressurized work port and output rotation.

2. Control case pressure.
The applicable 74318/74348 technical data specifies 1.7 bar [25 psi] continuous allowable case pressure. Excessive housing pressure can increase seal and rotating-group loading.

3. Match work ports and case drain ports exactly.
The 743XX installation drawings identify separate SAE O-ring work-port and drain-port configurations. Hose routing should follow the specific configuration drawing.

4. Avoid cavitation during startup.
Ensure proper charge/closed-loop conditions, clean hydraulic oil and adequate case-drain flow before commissioning a replacement motor.

5. Verify the shaft before coupling.
Different 743XX variants use different shaft geometries and allowable shaft torque ratings. Shaft diameter, keyway, spline form and extension must be matched before installation.

6. Do not assume optional equipment is standard.
Shuttle valves, charge-pressure valves, speed sensors and through-shaft configurations are option-dependent. Confirm the complete product code before advertising or supplying them.

7. Use configuration-level replacement control.
For aftermarket replacement, the correct engineering workflow is model number + configuration + dimensional interface + operating conditions + functional test, rather than simply matching “74318”.