Why a Waterproof DC Motor is Needed
The performance of an electric motor is greatly affected by its environment. Water is one of the most harmful factors for DC motors.
Typical brushed motors have vent holes in their end cap and housings, allowing air to pass through for heat dissipation. But water can enter these gaps and affect the insulation of the motor windings.
Vent Holes
In applications such as smoke vent HT fans where motors must operate continuously for long periods, it is important that moisture be prevented from entering the motor to prevent short circuiting and failure of insulation materials. In these cases, a motor may be fitted with anti-condensation heaters, cartridge heaters or silicon rubber strip heaters that are turned on when the motor is not operating and turned off when it is running. This keeps the motor warm enough to avoid condensation even if the temperature is significantly higher than ambient.
Another way to prevent moisture accumulation is by installing weep holes in the motor. This can be done in open drip-proof (ODP) motors, where the openings are designed to funnel water falling at an angle of 15 degrees or less from above into a drain or other means of evaporation. However, this only works well if the motor is mounted in a particular orientation.
In hazardous location or explosionproof motors, weep holes cannot be installed because the design requirements for these types of enclosures include metal-to-metal contact between the end housings and the frame as well as between the junction box and the frame. Therefore, normal weep holes cannot be installed, resulting in a need for alternative measures to reduce moisture accumulation.
Bearings
RC vehicles often use electric motors that can get wet. Whether this happens in the water or in the air, the motors can suffer damage due to moisture. This is one of the main reasons why a waterproof DC motor is needed. The industry has a standardized measure for liquid protection called the IP waterproofing class, and it is possible to create an electric motor with this type of protection. However, this comes at an extra cost and limits overall performance.
Dirty water can affect the commutators and brushes of a DC motor negatively. It may also cause rust on the metal parts of the motor. To avoid these problems, a waterproof motor needs to have moisture-proof bearings. These types of bearings are designed to handle axial and radial loads in varied conditions. They are used in a wide variety of applications and can be found in almost any type of electric motor. However, these bearings can be very expensive. They can also be difficult to find. If you are looking for an affordable option, consider purchasing a waterproof brushed motor.
Screw Holes
Many DC motors are used in applications where they are exposed to moisture. They are usually encased in plastic to help keep the water out and prevent moisture from Waterproof DC motor damaging them. It is very important that weep holes are positioned so that any water that does enter the motor can drain away easily, rather than being trapped inside the case and subjecting it to corrosion and other problems.
One way to waterproof a motor is to use an epoxy set to encase the motor in plastic and seal the lead wires. Various other hot-melt adhesives and resins can be used to further encase and protect the motor. It is also possible to use moldable plastics that will form a protective coating for the electrical components. Another method involves forming a layer of liquid epoxy against the casing and extending into the openings for the lead wires, and completely surrounding them. This is then allowed to cure before the motor is reassembled. The method can be particularly useful for protecting explosion proof motors. The end bells of these motors are machined to accept a spring loaded oil seal. Weep holes are drilled adjacent to the seals to provide passages that will drain moisture from the lowermost portion of the motor enclosure when it is mounted in its final position.
Specialized Cases
The motor manufacturing industry has a standard liquid protection measure called IP waterproofing class. Motors must comply with this rating in order to be able to work in a humid environment. These motors are also often used for applications requiring the use of chemicals and solvents. They come in a variety of power ratings and speeds to suit the needs of different applications.
Brushed DC motors are not typically considered to be waterproof, but there are some brushless versions that can be made water proof. The key is to keep water away from the commutator and the bearings. This can High torque BLDC motor be done by making the motor in a unique housing, and adding seals to protect it from moisture. This type of motor can be used in a wide variety of applications, including underwater RC vehicles and other marine applications.
Waterproof BLDC motors can be purchased online at an affordable price. They are a good choice for underwater operations because they are compact and lightweight, and they can be paired with ESC controllers and a propeller for a complete kit. The brushed waterproof motors are ideal for electric surfboards, submarine equipment, and drones.
Shaft Seals
Shaft seals are an essential component for keeping the inside of electric motors sealed off from the outside. These seals prevent dirt from getting into the bearings and windings, but they also prevent liquids from getting into the motor.
The most common shaft seals for electric motors are cased PTFE lip seals (Figure 2 labeled B). They are designed to fit tightly into open glands like oil seals and feature a metal case on the inside that provides strength and stability. They have a contact lip on the outside that is formed into a V-shape to reduce seal generated heat, which also helps to eliminate lubricant shear and asperity contact.
Most of these seals are directional and must be installed in the correct orientation to ensure that they work correctly. Electric motors are often subject to extreme pressures and temperatures, so they must be able to tolerate high running friction with minimal leakage. This is particularly important for battery-powered applications, where any inefficiency losses can translate to less power available from a single charge.
