In this article, we will go over five points on how to keep your electric motors running properly and help extend the life expectancy of your motors. We will go over lubrication, bearing inspection, checking your rotor and stator, motor mount, and how important keeping records are. Follow these and you should see sustained performance and reliability with your motors.
Lubrication
In this section, we will walk you through making sure the bearings on your electric motor are properly lubricated. Without proper lubrication, it will cause the bearings to wear out prematurely. Here are a few pointers on how to lubricate your electric motor’s bearings.
1. Don’t over lubricate your bearings. Over lubrication can cause the grease or oil to get into the windings. This will cause the insulation to deteriorate around the winding causing arcing and shorting inside the motor to the case. This will cause excessive heat and wear on the rotor and stator as well.
2. Always use the lubricant designated by the manufacturer. The use of other lubricants can do damage to the bearings, causing them to wear faster or unevenly.
3. Consult your manual or the manufacturer’s website to find out the proper interval for lubrication. Lubricating too often or not lubricating often enough could also cause premature wear in your bearings if under lubricated or degradation of the insulation around the winding if over lubricated.
Bearing Failures
Bearing failures are one of the most common and easiest problems to prevent. If your bearings fail, there are multiple things that could go wrong with your electric motor. This section will go over how to inspect the bearings on your motor and prevent unnecessary wear to the bearings.
1. Make sure your load attached to your motor is aligned properly. Misaligned loads can throw the rotation off-balance, straining one or both bearings.
2. Keep the motor clean of contaminants and moisture. You may have to blow out the motor every so often to keep it free of moisture and small particles that could work their way into the bearings.
3. Take temperature readings occasionally to monitor how warm or hot the bearings get. Compare those readings to the safe temperature range provided by the manufacturer. If the bearings are getting too hot, stop using the motor, let it cool down, and promptly inspect the bearings for damage or contaminants.
4. If you hear any abnormal sounds coming from your motor, you can use a stethoscope to better identify what part of the motor the sound is coming from. It is also preventative maintenance to just periodically use the stethoscope to listen for any abnormal sounds coming from the motor so you can address the issue before it does any further damage to the other components of the motor.
5. Check oil rings (if applicable) and keep an eye out for excessive shaft play. Excessive play in the shaft is a good indicator that you have a bearing that is defective or will be soon.
No one can imagine the world without electric tools and equipment which all work with electric motors. In many electricity-powered devices, there is an electrical motor that works silently and develops the functions. But what are they? What do they do? What are their features? If these are your questions too, follow the article. To get into the issue, I start with a brief history of it.
The Evolution of Electric Motors
Michael Faraday, a British physicist, is regarded as one of the most significant of the numerous 19th-century scientists who contributed to the discovery and development of electric motors. Faraday achieved the successful rotation of a wire using a magnet and a magnetic field created by an electric current in 1821. In 1831, he developed the law of magnetic induction, paving the way for considerable advancements in electrical motors and generators.
📌 Many additional forms of electric motors, as well as architectures that might be called the classic DC motor, have been developed over time.
Following that, the practical electric motor was found rather than invented in 1872, when one of the generators on display at the Vienna World’s Fair began rotating on its own after being unintentionally linked to another generator. This led to the realization that the same principles applied to generators could also be applied to motors. Generators became a mainstay of many sectors in the twentieth century as a result of the fast rise in their practical application.
Electric Motor diagramWhat Is an Electric Motor? What do electric motors do?
The electro-mechanical mechanism that transforms electrical energy into mechanical energy is known as an electric motor. Motors, in other terms, are devices that produce rotating force. The interplay of magnetic and electric fields is crucial to the operation of an electric motor, especially in cordless devices like cordless drills.
they generate rotational mechanical force in the armature—located on the rotor or stator—around the shaft by using electrical current to produce rotating magnetic fields. To turn electric energy into intense bursts of force and produce dynamic degrees of speed or power, numerous motor designs employ the same basic premise.
There are other energy sources such as Generators, their functions can be mistaken with that of electrical motors. Here I will debunk the misconception with a simple compare:
Generators turn mechanical energy back into electrical energy
Whereas, Electric motors convert electrical energy into rotation and various kinds of mechanical energy.
However, despite their opposing tasks, motors and generators have a lot in common in terms of design and functioning. In truth, all it takes is a simple experiment with two model motors coupled together to show that an electric motor may also function as a generator. But the two sorts of machines have traditionally been designed independently due to the distinct manner in which they are employed.
Now, let’s take a closer look at electric motors and talk about its parts and types.
Parts of Electric Motor
While electric motors vary in form and kind, many of them comprise the following parts and assemblies (starting at the center and working outward):
What Are the Advantages of Electric Motors?
they offer several advantages over other types of motors, including:
Electric motors can be found in a wide variety of tools, both handheld and stationary. Here are some examples of tools that commonly use electric motors:
Different Types of Electric Motors
When it comes to different types of electric motors, I should mention that they come in a variety of designs with different operating and safety characteristics, but some of the main electric motor types are the following:
An AC motor is a mechanism that transforms AC electrical power into mechanical power. This type of electric motor includes three types:
AC electrical motors are the most often used in the business because they offer various benefits:
A DC motor is a mechanism that transforms DC electrical power into mechanical power. Its operation is based on the basic idea that when a current-carrying conductor is put in a magnetic field, a force is applied to it, and torque is generated.
DC motors are also highly prevalent in industrial settings because, depending on the format they offer considerable advantages:
Each motor type has its own set of qualities that make it ideal for a variety of commercial and industrial applications. AC motors, for example, are versatile and simple to use. The following are some of their additional features:
Cordless DrillDC motors have their own set of traits, including:
Comparing these two, an important question arises:
Which is more powerful, an AC or a DC motor?
AC electric motors are typically thought to be more powerful than DC motors because they can create more torque with a higher current. DC motors, on the other hand, are more efficient and make greater use of their input energy. AC and DC motors are available in a variety of sizes and strengths to satisfy the power requirements of any business.
After comparing AC and DC electric motors and getting enough data about them, let’s get deeper in DC motors and check two types of DC electric motors them that play a leading role as power tool motors:
Brushed and brushless motors are the two most prevalent types of DC electrical motors (or BLDC motors).
A brushed or brushless DC motor may be utilized in numerous applications. They work on the same principles as coils and permanent magnets in terms of attraction and repulsion. Both offer benefits and drawbacks that may lead you to prefer one over the other, depending on the needs of your application. Here are their features:
DC brushed motors, as their names suggest, feature brushes that are utilized to commutate the motor and cause it spin. They have their specific structure including the following parts:
In Brushless electric motors, brushes are removed, so electronic control replaces the mechanical commutation function.
Brushless electrical motors today overcome many of the drawbacks of brushed motors by combining higher output power, smaller size and weight, improved heat dissipation and efficiency, wider operating speed ranges, and extremely low electrical noise. Brushless motors feature no electrical connections that might wear out, resulting in greater dependability and shorter maintenance intervals in commercial and industrial applications.
Both AC and DC motors can be designed to operate at constant speed or dual speed. The choice of which motor to use will depend on the specific application and its speed control requirements.
The process of selecting a motor and gearhead should begin with a thorough examination of the motor’s specifications to ensure that the motor you choose meets the application’s requirements. What you need to begin your selection is some factual and useful information the motors. The constant speed electric motor combines an induction motor with a power on activated type clutch and brake. It’s perfect for frequent start-and-stop operations. Suitable for situations where the motor is run at synchronous speed independent of load torque and the motor is started, stopped, and reversed frequently.
Dual-speed motors are a cost-effective choice for applications that only require two speeds, while also lowering the chance of failure. These motors are often constructed with an operational speed and a slower speed for easier starting. Without the need of a frequency converter, dual speed motors may push fans, pumps, hoists, and other machinery at two distinct speeds.
What Is the Difference Between Constant Speed and Double Speed Tools?
After a long journey in the world of DC and AC motors, let’s take a look at some of the leading features of Electric motors: RPM and Torque.
Motor’s rotational speed is the number of rotations of a tool per unit of time and is measured in revolutions per minute (RPM). In fact, RPM is a unit of measure used to show the no-load speed or frequency of a power tool.
The turning speed is considered an important factor depending on the type of work that we are going to carry out. Therefore, when we use an electric machine to work on hard surfaces such as concrete, we are interested in opting for more revolutions per minute.
This speed also has a direct relationship with the type of tool we use. For example, cordless drills typically offer a maximum speed of around 2000 RPM, while most corded drills typically operate at a speed of 3000 RPM.
The force that causes an item to rotate, measured in Newton Meters (Nm), is the greatest indicator of how strong your drill or impact driver is. The greater the figure in newton meters, the more twisting force it will give.
To measure the torque of an electrical motor, there are two methods:
Traditional Torque Rating Measurement Method:
New Power Rating Measurement Method:
Power Tool Torque Settings
When driving screws into tougher materials, you’ll need to go slower and apply more torque. You can adjust the depth of your drilling without inflicting any harm if you get these parameters perfect. To achieve the greatest results while drilling holes, the tougher the material, the faster the speed.
The concept of tightening torque expresses the amount of rotating force produced by the motor of a power tool. As an example:
However, the rotational speed, as the name describes well, shows the rotational speed of an electric motor. For example, the higher the RPM of a drill, the higher the speed of the bit.
Important note: Torque and rotational speed are not only different things, but they also have a completely inverse relationship. In simple terms, when a power tool offers high torque, it will have a low turning speed, and vice versa.
Conclusion
Considerations such as power source type, internal construction, application, and kind of motion output can all be used to classify electric motors. Aside from AC vs DC, motors can be brushed or brushless, single-phase, two-phase, or three-phase, and air-cooled or liquid-cooled.
Vacuum cleaners, dishwashers, computer printers, fax machines, video cassette recorders, machine tools, printing presses, autos, subway systems, sewage treatment facilities, and water pumping stations are all examples of electric motors’ importance in modern life. The new period, on the other hand, heralds a greater focus on detail as a result of development, law, and the need to remain competitive. As a result, systems become more complicated, and resources scale up in response. Making an expert system is unquestionably an engineering problem, and minor percentage efficiency increases can help pave the path to the optimized/green future we seek. The objective is to fine-tune and develop motor designs and control algorithms.
FAQ ❓
What are Electric Motors Used For?
Electric motors are used for converting electric energy into mechanical energy.
What Are Different Types of Electric Motors?
Electric motors are offered in two main types: Alternating Current (AC), Direct Current (DC). While AC motors have three types: Induction motors, synchronous motors, linear motors.
What Tools Use Electric Motors?
Electric motors can be found in a wide variety of tools, both handheld and stationary. Here are some examples of tools that commonly use electric motors: Power drills and drivers, electric saws, air compressors, exercise equipment, electric vehicles, such as cars, bikes, and scooters.
What Is the Function of Motor in a Tool?
Electric motors are in charge of converting electric energy into mechanical energy.
Do Power Tools Use Ac or Dc Motors?
Both AC and DC motors have their advantages and disadvantages, and the choice of motor will depend on factors such as power requirements, efficiency, weight, and cost.
When compared to brushed DC motors, what are the benefits of brushless DC motors (BLDC motors)?
Brushless DC motors (BLDC motors), which do away with brushes and commutators with mechanical contacts, are low-noise, low-maintenance, and capable of high-speed operation.
What is the brush material in a DC motor?
Metal, carbon, and metal-carbon composites are common materials for brushes. Some metal brushes use a commutator to apply precious metals like gold to a contact surface. A brush’s substance is carefully selected based on electric voltage/current as well as economic considerations.
What are the components of a basic motor?
An armature or rotor, a commutator, brushes, an axle, a field magnet, and some type of DC power source make up a basic motor.
What is the maximum lifespan of an electric motor?
If operated under typical operating circumstances, an electric motor can last between 15 and 20 years under test settings.
Is it better to use a DC or an AC electric motor?
Although AC motors are more powerful and require less maintenance, DC motors are more energy efficient. The use of the electric motor has an impact on whether AC or DC is chosen.
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