Mechanical friction disc

Types of mechanical friction discs

Mechanical friction discs are circular objects used by mechanical engineers to provide resistance to any object that is about to move. The status quo is maintained by the friction disc in question, and there are numerous ways to divide these mechanical friction discs into groups.

• Application-based segregation

  One way of categorizing friction discs is by their applications. Some friction discs are used as brakes, for cars, for example, while some friction discs serve the purposes of clutches. Other machines and devices utilize the friction disc's inherent property to resist motion and employ them for a different purpose, such as an energy harvesting machine.

• Material-based categorization

  This kind of segregation is the most popular, as each machine that employs a friction disc will have a preference for material based on the machine's needs and constraints. The main materials used are cast iron, asbestos, resin, and steel, although new materials and composites are being developed constantly.

• Design-based separation

  Common design-based segregation includes the single friction disc, which has only one friction surface, or the multiple friction discs, which have several discs stacked together.

  Stacked multiple disc assemblies are more common in automobile clutches. Friction discs may also comprise metallic and non-metallic materials.

Specification and Maintenance

Some specifications scrutinized to understand the mechanical friction disc include the size and weight ratio, voltage, current, and power rating.

• Size and Weight Ratio: An optimal weight-distribution ratio is critical in power transmission applications that demand stability at high rpm. The engineered material used to manufacture the disc, such as metal or ceramic composite, influences the sizes and weight ratios.
• Voltage, Current, and Power Rating: The voltage and current rating are critical for application in industries such as automobile and aerospace. For automobiles, the starter motor discs have a power rating of about 1-2 horsepower. Mechanical friction discs power some street motorboards up to 5-10 horsepower. Power rating also varies in washing machine friction discs; up to half a horse disc used in the spin section. Heavy machinery such as aircraft and industrial turbines have a high-voltage rating of 12-28 aircraft discs used in the aerospace industry.

Mechanical friction discs undergo various types of tests during the manufacturing process to meet the set standards. The tests include torque, bite force, and wear pattern analysis. After installation, the discs need to be maintained frequently for optimal performance and longevity. Starter motor maintenance tips include cleaning starter solenoid contacts, especially the mechanical friction contact parts. If there is no mechanical part cleaner, one can use anti-oxide spray solenoid contacts to engine clean. The cleaning improves conductivity and reduces resistance.

Another maintenance part tip is to inspect the solenoid wiring for mechanical disc friction starters. A worn wire may result in starter failure. Worn wires may expose a portion that can get in contact with the disc, increasing the risk of starter failures. Wrapping a wiring harness with electrical tape prevents the harness from getting into contact with the friction disc. Further, do not grease or lubricate the parts of the starter solenoid, including the springs and mechanical friction parts. Lubricating parts can attract dirt and debris that may affect the solenoid's functionality.

Cars with push-start systems do not have starter solenoids. Thus, there is no need to clean the solenoid starter contacts. However, the discs can be maintained by applying a coating to improve corrosion resistance.

Usage scenarios of mechanical friction discs

Mechanical friction discs are used in a wide range of industries and applications, which is perhaps why they are so familiar to many people. Here's a breakdown of some key usage scenarios for mechanical friction discs.

One main area where mechanical friction discs are used is in brake systems. They are typically found in brake pads and braking machines. Specialized friction discs known as braking friction discs help to slow down or halt the movement of machines. This is done by converting the machine's kinetic energy into heat energy through the process of friction. The braking machine works the same way, and the mechanical friction disc connects to it in an almost similar fashion. It is a very common usage scenario when it comes to the application of mechanical friction discs.

Mechanical friction discs are also used very commonly in train systems. Once again, they're found in the brake pad system of the train. Research shows that friction modifiers acting upon the mechanical friction discs of trains can greatly improve braking performance and reduce noise.

In the automotive industry, the mechanical friction disc is usually an integral part of the clutch system. When pressed upon the clutch pedal, the clutch disc moves with the clutch disc, which creates the necessary friction required to separate the flywheel from the engine and power the vehicle forward.

Mechanical friction discs aren't just used in brake and clutch systems in automotive industries. They are also used to polish or grind metal in metalworking machines like an angle grinder. Power tools like the impact sander also have mechanical friction discs that help smoothen out surfaces when sanding with minimal required power.

How to choose mechanical friction discs

When choosing mechanical friction discs, the following factors are important to consider.

• Usage scenarios and types

  The application scenario should be considered to choose the right type of mechanical friction discs. Double-face discs are suitable for devices requiring higher loads, space-limited, and more complex transmission mechanisms. The single-disc, on the other hand, is more suited for simple, cost-effective solutions. Friction discs with sleeves are often used in conjunction with self-aligning hubs to help reduce a hub's bending moment, while self-aligning hubs are used to fix the disc in place. The friction disc packs are used in high-torque applications, while the key drive type has the advantages of high torque transmission capacity, greater flexibility, and low slip rate. Please choose a suitable type according to the applicable environment.

• Size and weight

  Size and weight are also crucial when choosing a mechanical friction disc. The inner diameter, outer diameter, thickness, and weight are all parameters that need to be considered. They must be matched with the driving shafts, hubs, and other related components to ensure a proper fit.

• Material

  The material of the friction disc has an effect on its durability and performance. Choose the material according to the friction disc's operating conditions and needs. For example, rubber is applicable to some specific fields or requirements, and phenolic is not applicable under high-moisture or high-temperatures environments.

• Quantity

  When choosing a mechanical friction disc, it is necessary to determine the quantity in consideration of the budget, demand, production capacity, and supply capacity.

Mechanical friction disc Q and A

Q1: How is mechanical friction disc test carried out?

A1: In the disc brake test, two parallel discs of the materials under investigation are clamped together. The material will be placed between them. The discs will be rotated to simulate braking action. The main variables in friction testing are temperature, sliding velocity, contact pressure, and wear mass loss.

Q2: How important is mechanical friction in machinery?

A2: Mechanical friction plays a very important role in all types of machinery and equipment. In the absence of mechanical friction, machines would not work because moving parts would become loose and gain inadequate connectivity. However, a little bit of friction is very important for the movement and operation of mechanical parts.

Q3: What happens to mechanical parts with too much friction?

A3: Excessive mechanical friction between moving parts may lead to the parts getting stuck or damaged. This may lead to the machinery breaking down. Furthermore, too much friction may lead to unnecessary wear and tear, which may reduce the lifespan of the product.

Q4: What is the relationship between mechanical friction and energy?

A4: Mechanical friction plays a very crucial role in the dissipation of energy. Whenever friction occurs between moving parts, energy may be dissipated in the form of heat. This may result in the machinery and equipment using up energy unnecessarily.