Geared Motor

Savings on Expenses
Using a gear motor to increase torque and lower speed eliminates the expense of running the system. The effectiveness and dependability of gear motors provide instant benefits to an application. Several gear motors are inexpensive and easy to install and need little maintenance, resulting in reduced unplanned downtime to replace the gears.

Reduced Speed
Gearheads are sometimes known as "speed reducers." Gear ratios are also known as "speed reduction ratios" at times. Whilst speed controllers now handle speed reduction, gearheads were formerly employed to lower the speed of a motor. When using a geared motor, the speed of the motor is split by the gear ratio. An 1800 RPM AC synchronous motor with a 5:1 gearhead, for instance, will operate at 360 RPM.

Environmental Advantage
Reliable speed reducers can save a lot of money on energy and motor components. Furthermore, gear motors benefit both the environment and the employees who use them. Commercial electric motor systems account for around one-twelfth of total greenhouse gas emissions from fossil-fuel energy plants. The generation of greenhouse gases may be greatly decreased by lowering motor power usage with effective speed reducers, such as gear motors.

Torque
When directly connected to the motor axle, gear motors offer an advantage. This results in a mechanical advantage depending on the ratio of the number of gears to the number of teeth on every gear. For instance, if a motor produces 100 lb-in. of torque, adding a 5:1 gearhead produces 500 lb-in. of output torque.

Increased Rigidity
Geared motors are more robust and resilient to torsional stresses. As a result, as compared to conventional motors, geared motors are less prone to problems generated by load torque variations. Even though the load fluctuates, high stability and position precision may be expected. For instance, higher gear tension in a geared motor gives more holding torque, allowing a surveillance camera to remain in place even in high gusts.

Improved Damping Characteristics
If the inertial load is large or acceleration/decleration rate is high, a geared motor can increase damping effects more effectively. This ensures more stable operation compared to an ungeared motor; especially during starting and stopping. Geared motors are ideal for applications where a large inertial load, such as an index table, must be driven.

Shorter Positioning Time
For large inertial loads, the use of a geared motor will achieve a shorter positioning time than a standard type motor. In the graphs below, we compare the fastest positioning time between an ungeared closed-loop stepper motor and a geared closed-loop stepper motorat 5:1 inertia ratio and 30:1 inertia ratio.
As you can see, at 5:1 inertia ratio, the geared motor takes longer than the standard type. However, at 30:1 inertia ratio, the geared motor can position faster until a certain point (540°).

Drive Large Inertial Loads
When a geared stepper motor or servo motor is used, the inertial load that can be rotated increases by the square of the gear ratio in comparison with an ungeared motor of the same size. Bascially, you can drive an exponentially bigger inertial load with geared motors.
When using different types of motors, pay attention to how the inertial load is treated. We show some examples below.
For AC motors, we follow this formula below. When gear ratios are less than 3:1~50:1, we multiply the rotor inertia by the gear ratio squared. For gear ratios of 60:1 or higher, we only multiply the rotor inertia by 2500 as there is a limit.

Know Your Application Requirements for Your Gearmotor
The first step in selecting a gearmotor is reviewing your application requirements. These include but are not limited to:
General requirements: Envelope size, mounting orientation, mounting type and size, overhung and side loads, shock load and lubrication type.
Input power source: Voltage, frequency (Hz), maximum current (Amps) and control type, if applicable.
Gearmotor specifications: Size, weight, desired noise level, life expectancy and maintenance level.
Gearmotor performance: Speed, torque, duty cycle, horsepower, starting and running torque (full load).
Operation environment: Application and ambient temperature, and ingress protection (IP) rating.

Know the Speed and Torque Requirements of The Load to Be Driven
To ensure your gearmotor is properly sized for your intended application, it's important to know your output speed, starting and running torque. Selecting the proper gearmotor is a matter of matching output speed (RPM) and torque to your application's needs. The output speed is determined by your machine's requirements and should be already known. That leaves the starting and running torque to be determined. Keep in mind, when you choose a pre-engineered gearmotor, the manufacturer has done most of the heavy lifting to ensure the motor and gearbox will work seamlessly.
Once you have calculated the starting and running torque needed, you will also need to review the gearmotor's potential design limitations, including the running (full-load) output torque, output speed, overhung load, shock load, thermal characteristics and duty cycles.

Select the proper motor
Next, use your list of application requirements and compare them to the motor specifications of the different types you are interested in such as a universal, brushless DC, AC induction or a permanent magnet DC gearmotor. Because each application has its own unique characteristics and requirements, it is important to note which factor such as horsepower, starting torque or efficiency is most important to your application. During this phase, you may decide that matching a gearbox and motor separately will best suit your needs.

Test the motor
Once you have selected a gearmotor, it is important to run several tests to ensure the motor runs well in a typical operating environment. If the motor becomes unreasonably hot, is too noisy or appears stressed, repeat the motor selection process or contact the manufacturer.
Taking the time to properly size your gearmotor will help ensure that it will last for years and operate at peak efficiency.

Maintain Good Housekeeping
Although it may appear simple, gearboxes frequently operate in a dirty and dusty environment. While to some extent this is unavoidable, it is critical to minimise the consequences of the employment environment. Such a dirty and rusty environment could raise the gearbox's working temperature or perhaps cause it to become contaminated. As a result, industrial gearboxes should be dusted and brushed clean on a regular basis.

Conduct Regular Inspections
While a full inspection may appear to be too difficult, a simple visual inspection of gear contact patterns through an inspection port can help prevent catastrophic failures in the future. If there isn't any in-house inspection experience, an expert might be recruited to execute the examination and train people.
By overcoming problems for conducting an inspection, you can help to extend the life of your gearbox and avoid catastrophic failure. This could save time, money, worker harm, and damage to nearby equipment.
Before opening the gearbox inspection port, you should conduct a comprehensive external inspection. Use an inspection form to keep track of critical information that would otherwise be lost once the cleaning is done. Examine the exterior of the gear housing for symptoms of overheating, corrosion, contamination, oil leaks, and damage before cleaning it.
Tightening torque of structural fasteners carrying large stresses, such as torque arm bolts is to be measured and corrected Look for signs of movement at structural interfaces, such as cracked paint or fretting corrosion. Note the condition of the fasteners and look for fretting corrosion or other signs of movement on load-bearing surfaces of components, for taking corrective action.

Keep an Eye Out for Overheating
Overheating can be detected by discoloured or burned external paint, as well as dark oil in the sight glass. Using an infrared temperature gun, monitor the gearbox temperature on a regular basis and look for any rapid variations in temperature. Overheating can be detected by the following symptoms:

• Shafts, seals, and breathers all emit smoke.
• Housings with discoloured or burned paint
• Water placed on the housing or shafts immediately evaporates, boiling or crackling.
• Colors should be tempered on unpainted surfaces.
• Components made of melted plastic, such as shipping plugs
• Low levels of oil in the sight glass or on the dipstick
• In a sight glass or on a dipstick, there is a dark oil.

Foam in the sight glass
Sludge on the filter element or water in the sight glass (may indicate oil cooler failure)
Chip detectors, filters, or metal chips on magnetic plugs (may denote gear or bearing failure caused by overheating)

Look for Wear & Tear Signs
Internal gears can be inspected by removing inspection covers or using an endoscope. Look for pitting and spalling as evidence of wear (material from the surface of gear tooth flanks being removed). Using 'engineers blue,' check the contact patterns between gear teeth for misalignment, since this could indicate bearing or bearing housing wear.

Conduct Vibration Analysis
Since many gearboxes work in a noisy environment, not all changes in gearbox noise can be captured. Vibration study of the internal bearings and gears on a regular basis will identify any substantial changes in the gearbox's internal condition and help prevent any unanticipated production loss.

Check the Condition of Your Shaft
Check for any increase in backlash between the gears' mesh, as well as any increase in end play or lift at the input and output shafts, with a dial indicator. Backlash increases could be a sign of gear tooth wear, which isn't usually evident to the human eye. Increased shaft end play or lift indicates wear in the bearings' rolling elements, as well as wear in the bearing housings.

Speak to Our Specialists at Premium Transmission
Bring in the specialists who can advise you and assist you to guarantee your site's gearboxes are running to their full operational efficiency, by providing guidance or support in inspecting, maintaining and repairing, or replacing your gearbox.