Speed controls, including speed regulators and rate controllers, are used to decelerate and regulate the speed of loads such as moving carriages and machining feeds near the end of their travel. They frequently use fluid dampening methods such as a piston and cylinder combination with controlled fluid flow through an orifice. The regulator method for speed controls is important to consider. Regulator methods include hydraulic, air, gas, and elastomeric. Hydraulic speed controls utilize hydraulic liquid to absorb shock and dampen or slow motion. Air regulated speed controls use atmospheric air to dampen and absorb shock. Gas regulated speed controls utilize a special gas other than air to absorb shock; nitrogen is one common example. In an elastomeric speed control a synthetic elastomer or rubber is used to absorb shock or impact.
An important parameter to consider when specifying speed controls is the regulator action. The regulator action can be compression or extension. In a compression speed control the shock absorption or dampening occurs in the compression direction. In an extension speed control the shock absorption or dampening occurs in the extension direction. A double acting speed control acts as a speed regulator in both compression and extension directions. Important specifications to consider when searching for speed controls include the stroke, maximum force, cylinder diameter or maximum width, and the rod diameter. The stroke is the difference between fully extended and fully compressed position, this is also referred to as the rod travel. The maximum force refers to the maximum rated force for shock absorber or damper. The cylinder diameter is the desired diameter of housing cylinder. The rod diameter is the desired diameter of extending rod.
Materials of Construction
Common materials of construction for speed controls include aluminum, steel, stainless steel, and plastic. Common features of speed controls include adjustable construction, fast return construction, and remote control. An adjustable construction allows user to fine tune desired damping, either continuously or at discrete settings. Fast return has valving that is included to allow rapid rod return to unengaged position. Speed controls can have a remote control mechanism such as a cable for adjustment control of devices installed in inaccessible areas.