Fan drive hydraulic gear motors are bidirectional

Paul Boughton
Sauer-Danfoss is introducing new features on its SGM2 and SGM3 aluminium fan drive gear motors: integrated reversing and proportional valves; a bi-directional motor for remote HIC reversing valves with shaft seal protector and cast iron cover; and outrigger bearings for slewing, high-vibration, and oscillating fan drive applications. These new features help OEMs achieve Tier IV and Stage 3B emissions compliance. In addition to these features, the SGM3 also offers 250bar (3600psi) pressure capability across all displacements.
 
The SGM motors were introduced in April 2009 and have now been enhanced for high-performance fan drive systems. Rob Arndt, product sales support manager for Sauer-Danfoss, comments: "These fan drive motors are robust in dusty, dirty environments. With Tier IV and Stage 3B emissions regulations, we will have applications with higher-horsepower fans, more aggressive duty cycles, and higher temperatures. Because new vehicle systems will reject more heat, the fans operate longer and more often for cooling."
 
Now, with the new features, the SGM motors run in both directions to quickly clean radiators of dirt and chaff, offering a compact system for high-performance Tier IV and Stage 3B fan drive systems. Arndt says: "The base models already helped recapture some of the lost power from the constraints imposed by emissions standards. These enhancements help recover additional power."
 
The enhancements to the SGM motors continue to focus on key product attributes: increased performance, extended life or durability, and installation flexibility. On both the SGM2 and SGM3, two anti-cavitation shock valves are standard, with open transitional directional control valve spools, protecting the motors during high performance fan reversals.
 
Unlike other motors on the market, the SGM2 and SGM3 are not pressure de-rated due to poor valve performance. In addition, they are claimed to be the only fan drive motors with two valves, thereby helping to clip pressure spikes in both directions of fan rotation. These two features give OEMs more power utilisation due to higher-pressure capabilities.
 
The SGM2 features the D03 valve, a two-position directional valve that controls fan rotation, while the SGM3 features the D05 valve. High-temperature seals enable operation from -20 to 110 degrees C.
 
With its 250bar pressure capability, the SGM3 can be applied on higher-horsepower fans with increased cooling demands.
 
Sauer-Danfoss says that the enhanced SGM fan drive motors trim fan speeds during optimal conditions, and they provide efficient reverse radiator cleaning. This reduces fuel consumption and operating costs due to excessive fan speeds and plugged radiators.
 
The SGM2 and SGM3 are claimed to be the only aluminium fan drive motors on the market with a steel rear cover to handle higher pressure and durability requirements, with equally matched valves. In addition, outrigger bearings provide increased capability for heavy metal fan blades and for machines that swing with high gyroscopic loads. Outrigger bearings mean the fan drive motors can be used with higher-horsepower fans, shock loads, radial and axial loads, slewing and oscillating applications. A dust protector in installed as standard with the outrigger bearing for extended life.
 
New outrigger bearings are available for all existing SGM2 and SGM3 fan drive motors from Sauer-Danfoss. The motors come as standard with 12V or 24V Deutsch connectors to handle dusty, dirty operating conditions.
 
The SGM2 and SGM3 fan drive motors are delivered ready-assembled, including the factory sealed outrigger bearing and integrated reversing function. Engineered for tight spaces, they are claimed to be the shortest on the market among similarly featured fan drive packages.
An electronic interface makes the SGM motors fully Plus+1 compliant for integration with Plus+1 microcontrollers and other compliant products, including sensors, joysticks and graphical display terminals.
 
For more information, www.sauer-danfoss.com

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