A gear motor is a specific type of electrical motor that is designed to produce high torque while maintaining a low horsepower, or low speed, motor output.
Gear motors can be found in many different applications, and are probably used in many devices in your home.
Gear motors are commonly used in devices such as can openers, garage door openers, washing machine time control knobs and even electric alarm clocks. Common commercial applications of a gear motor include hospital beds, commercial jacks, cranes and many other applications that are too many to list.
Basic Principles of Operation
A gear motor can be either an AC (alternating current) or a DC (direct current) electric motor. Most gear motors have an output of between about 1,200 to 3,600 revolutions per minute (RPMs). These types of motors also have two different speed specifications: normal speed and the stall-speed torque specifications.
Gear motors are primarily used to reduce speed in a series of gears, which in turn creates more torque. This is accomplished by an integrated series of gears or a gear box being attached to the main motor rotor and shaft via a second reduction shaft. The second shaft is then connected to the series of gears or gearbox to create what is known as a series of reduction gears. Generally speaking, the longer the train of reduction gears, the lower the output of the end, or final, gear will be.
An excellent example of this principle would be an electric time clock (the type that uses hour, minute and second hands). The synchronous AC motor that is used to power the time clock will usually spin the rotor at around 1500 revolutions per minute. However, a series of reduction gears is used to slow the movement of the hands on the clock.
For example, while the rotor spins at about 1500 revolutions per minute, the reduction gears allow the final secondhand gear to spin at only one revolution per minute. This is what allows the secondhand to make one complete revolution per minute on the face of the clock.
Gear Motors and Increased Force
Gear motors are commonly used in commercial applications where a piece of equipment needs to be able to exert a high amount of force in order to move a very heavy object. Examples of these types of equipment would include a crane or lift Jack.
If you've ever seen a crane in action, you've seen a great example of how a gear motor works. As you have probably noticed, a crane can be used to lift and move very heavy objects. The electric motor used in most cranes is a type of gear motor that uses the basic principles of speed reduction to increase torque or force.
Gear motors used in cranes are usually specialty types that use a very low rotational output speed to create incredible amounts of torque. However, the principles of the gear motor used in a crane are exactly the same as those used in the example electric time clock. The output speed of the rotor is reduced through a series of large gears until the rotating, RPM speed, of the final gear is very low. The low RPM speed helps to create a high amount of force which can be used to lift and move the heavy objects.
Tips for Maintaining a Gear Pump
A gear pump is a type of positive displacement pump that is used to pump low or high viscosity fluids. However, the most common application of a gear pump is that of using one to pump hydraulic fluid in various types of vehicles. The most common example of a gear pump is the hydraulic gear pump that is used in the transmissions of many vehicle. However, there are many other applications that use a gear pump as well.
Regardless of the type of gear pump you are working with, a few good maintenance tips might be able to save you the considerable expense of having to repair one. Therefore, this article will focus on a few ways to keep a gear pump in your vehicle in tip-top shape.
Checking for Signs of Wear and Tear
In order to keep your vehicle in good running condition, you need to perform periodic maintenance and service to the car. Your maintenance should also include the periodic checking and service of the gear pump in your vehicle. You will need to be handy with a screwdriver and a bearing puller in order to properly maintain the gear pump; however, servicing the gear pump yourself can save you a bundle versus having it done at a car repair shop.
When you examine the gear pump in your vehicle, check the teeth in the gears for signs of wear and tear. A brand new gear pump usually ships with a clearance of about 0.005 to 0.007 inches between the teeth of the gears and the chamber wall. This clearance is just enough for a piece of very thin wrapping paper. Therefore, you can use this type of paper to check the clearance between the gear teeth. If the paper slides in and out between the teeth too easily, then the gears have been worn due to scrubbing or poor lubrication.
The Pump Bearings
Another important component of the gear pump is the bearings. Therefore, you should occasionally check them for signs of wear as well. Good bearings should be completely round, while defective bearings will often appear to be oval, or egg-shaped. Defective bearings allow the gears in the pump to shift position in the chamber, rather than remaining straight and true.
You will need to remove defective bearings by using a bearing puller. The device uses a collet to remove the bearings and you should be able to pick one up at your local automotive tools store. If you are lucky, however, you may be able to remove the entire bearing assembly. It will depend on the make and model of your vehicle and the type of gear pump that is used.
Other Things to Check
Although the bearings and gears are the components most susceptible to damage in a gear pump, there are other areas that you should occasionally check as well. For instance, the pin that holds the gears into their shafts is crucial to reliable operation of the pump. If the pin becomes sheared or cracked, it could lead to a gear pump that does not function at all. Likewise, you should carefully inspect the pump cover for bulges or cracks that could indicate there are pressure problems in the pump.