In aerospace, there are many components involved in power generation. One of these components is slips whose function is to control the transmission of electrical signals and regulates the power generation in aerospace. This happens between two components, one that is stationary and other one that is rotating. With varying functions, the design of the slip rings also varies accordingly. For example, a slip rings whose function is to transmit data will have improved electromagnetic interference along with a great bandwidth. In this slip ring, the electromagnetic mitigation is better in contrast to the one that transmits power. However, the basic components like rotating rings and brushes are same for all types of slip rings for aerospace use. The slip ring is used to make the functionality in aerospace more simplified and improves the performance of machinery. In technical terminology, a slip ring has the function of creating an electric connection between the rotating machine structure.
In slip rings the electric power generated continues to help in working of motors and solenoids that triggers the operation of hydraulics in the slip rings. In slip rings, the transmission of data signals can vary accordingly. It can be used for either transmitting audio and video, information that is digital, sensors and also helps in preventing extra maintenance. The slip rings are put into varying categories by the manufacturers according to their features and requirements. The varying factors can include the frequency of data signals as the design gets more complicated in high frequencies and greater speeds.
Adding different features ensures that each slip rings offers a unique function in contrast to the other one. The mechanical designs have been streamlined to avoid the use of wires in the joints of machine that are moving. This feature is greatly used in aerospace technology and also in wind turbines, industries and medical.
Pancake slip rings
These slip rings are designed for areas where the vertical space has a limit while the horizontal space does not have much restrictions. To ensure that the rotation of slip ring and transmission of electricity is unaffected, it has vacuum sealing technology and metal brushes installed in it. These slip rings ensure that the torque remains low in the slip rings for aerospace use. The low friction of the slip rings is an advantage as it ensures the smooth running in the slip rings for aerospace use. This slip ring has comparatively a longer life and is does not produce loud electrical noises. The function of this slip ring is transmission of both power and signal in aerospace technology and can used in combination with fluids transmission.
Wireless slip rings
Unlike pancake slip rings, this slip ring does not require the technology of brushes and metal. As the name suggests, these slip rings transmit data through a magnetic field and do not involve nay wires in the process. The magnetic field is created by the coils and the stationary transmitter. These slip rings are considered a revolutionized version of slip rings since they do not have the typical mechanical parts of slip rings. Being an updated version, they can continue to work smoothly even in harsh conditions and require very little maintenance. But in contrast to the traditional slip rings, these slip rings have limited power transmission.
Mercury-wetted slip rings
These slip rings have a limit to the power they support varying from model to model. The slips rings for aerospace use are designed specifically with a coating of stainless steel or alloy of aluminum to avoid rust from attacking the structure of the slip ring. The rotating objects work on transmission of signals that can include minor voltages, varying frequencies, audio and video signals. Moreover, it can also control the electrical power connections in aerospace. It requires no maintenance as it is sealed with special material and hence is more reliable than the traditional slip rings.
Propeller Slip Rings
In the aircrafts where the wing propeller is fixed, these specialized slip rings are used. These slip rings have a deicing function and transmit electrical power from the generators of the machines to the propellers. The propellers in slip rings are heated to ensure that ice is not deposited or built up on the machine in extreme cold conditions either in flight or on the land. Propeller slip rings also involve the standard brushes and rings technology. These are manufactured with a smooth finish to ensure that the machinery continues to work at its optimum pace.
High Sky type Slip Rings
The slips rings typically used in aerospace are the high sky type slip rings. These slip rings control the transmission of both the signals and power currents among the stationary and rotating parts of the slip rings. This process continues from the ground to in space environment. The model is made specially to withstand high tensile strength according to the varying conditions. Unlike its function, it is light in weight and has a standard small size. It is ideal for use in aerospace since it can be relied upon for power transfer between the high currents and voltages. It can even continue to function in extreme weather conditions like heavy rains and storms. The features of high sky type slip rings include the altitude which can range up to 21000 meters. The design ensures that friction is minimized by multi point contact. It has high resistance to contact and fluctuations hence require low maintenance.
The size of slip rings can vary according to the function. It can range from one inch to a diameter of several feet. The actual goal is to reduce the size of the conductor rings that are used. This enables the sliding contacts to wear out at a much slower rate and also the distance that is covered linearly in each revolution is reduced. The life span of smaller conductor is much longer than those that are comparatively larger in size. The slip rings can be mounted to the machine using a threaded rotor, shaft or can simply be installed in a shaft cavity.
Concerns When Using Slip Rings in Aerospace
The electromagnetic induction should always be considered when the design of a slip ring is looked over. The voltages of dc signals are also likely to vary when it is turned off and on. In slip rings used in aerospace it is always ideal to shield the signals passing through using physical electrical path. The channels in between the slips should also be an important consideration in the designs. As slip rings are used in aerospace, the surrounding conditions like that of weather are not always predictable. It is best to consider all environmental characteristics in the slip rings. The sliding of the slip rings can be affected by any shocks and vibrations caused by external factors. The protection level should be managed accordingly in each slip ring by checking the features of the slip rings and the conditions it works in when sealing is done.
Slip rings are an essential component of the aerospace technology. Over the period of time, due to new technological advancements better versions are being introduced to improve the functionality of slip rings in aerospace.