Mobile and General Purpose Products

Mobile and General Purpose Products

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What is Inside vs. Outside Mount?

What is Inside vs. Outside Mount?
We are not talking about the weather here.

Mobile clutches are electromagnetic clutches that mount on pumps or compressors. They mount directly onto the pump or compressor shaft. These are used on underhood applications on tow trucks, service vans, ambulances, snowplows, construction equipment, utility trucks as well as other applications including ice resurfacing equipment, street cleaners, fishing boats and agricultural equipment.

These clutches are normally two-piece construction. This means that the coil (or field coil) is mounted separately from the armature/pulley assembly. Since the coil does not rotate, it is mounted directly to the pump body. The armature assembly is mounted to the rotating shaft.

A straightforward way to mount a coil is with a flange mount. We call this an "outside mount." The bolt circle diameter is outside of the coil's OD.

For an "inside mount," the coil is bolted to the pump on a bolt circle that is inside the coil's diameter. After the coil and armature assembly are mounted, the mounting bolts are not visible. This type of mounting style is great for compact installations where mounting space is limited.

For either type of mounting style, it is important to make sure that the field coil is perpendicular and concentric to the shaft. By nature of mounting directly onto the shaft, the armature assembly will already be concentric to the shaft. The alignment of the field coil is essential to prevent rubbing of the two major components. That rubbing is called rotor strike. Rotor strike causes major heat buildup and can damage a clutch within seconds.

Ogura MA Series mobile pump clutches are available with static torque ratings ranging from 58 to 175 lb.ft. A variety of bore sizes and pulley options are available from stock.

Benefits of using an Ogura mobile clutches:

  • Long life
  • Safety and convenience with remote starting
  • Fuel and energy savings
  • Built for outdoor operation
  • Many years of proven success
  • Custom designs available based on minimum order quantities
  • Reduced engine load on cold weather starts
  • Increased operational life of driven equipment
  • Simple installation






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