月: 2023年2月

What Is a Ball Roller?

A ball roller is a component that holds a ball, such as a metal ball, in a rotatable and partially exposed surface condition. Often referred to as a freebear or ball caster, it differs from general casters which use a one-degree-of-freedom rotating mechanism. Ball rollers can rotate 360 degrees smoothly in any direction, providing greater flexibility and movement.

They are commonly used as casters for carts to enable omnidirectional movement and as conveyance platforms in packaging operations to facilitate the smooth movement of products in various directions.

Uses of Ball Rollers

Ball rollers are ideal for applications requiring smooth rotation in any direction. They are used in cart casters, enabling easy orientation and movement. This feature is particularly beneficial in robotics, where responsive and multidirectional movement is essential. Additionally, ball rollers are implemented in conveyors to move and rotate products at right angles, which is especially useful for sorting packaged products.

Principle of Ball Rollers

Ball rollers consist of a main rotating ball supported by smaller balls (sub-balls) or three rotating shafts. This structure allows for smooth rotation with a low coefficient of friction, reducing resistance. However, when used as casters, their low surface friction and minimal elastic deformation can result in reduced ability to handle uneven surfaces.

The performance of ball rollers can be affected by surface conditions, as scratches on the ball or contamination can hinder rotation. They are made from materials such as steel, stainless steel, or POM, an engineering plastic with self-lubricating properties. Metal ball rollers often require lubrication to reduce wear, and removing this lubricant can lead to dust generation due to increased wear.

What Is a Bearing Holder?

A bearing holder is a device used in various machines to support bearings in the correct position to receive the load and rotation of a rotating shaft. It is attached to the machine’s body and holds the bearings by fitting them. The design of a bearing holder must match the load that the bearing is subjected to, and it should have sufficient rigidity based on the bearing size.

Uses of Bearing Holders

Bearing holders are predominantly used in industrial machinery. They must be rigid enough to withstand the load received by the rotating shaft. Considerations such as surface roughness of the bore and corner radii size are important. Bearing holders simplify the design and manufacturing of the housing part that holds the bearing. They are typically mounted as single or double bearing holders for deep groove ball bearings. For angular contact bearings, they can be used with a back-mounted double bearing or with an additional deep groove ball bearing.

Principle of Bearing Holders

Bearing holders serve the following functions:

1. Rigidity

Rigidity is crucial to ensure that the rotating shaft remains in position under load and maintains smooth rotation. Misalignment can cause issues such as gear meshing inaccuracies, noise, or gear damage.

2. Positional Accuracy

Bearing holders are typically screwed to the machine body. Precise alignment of screw holes and bearing holding holes is vital for correct shaft positioning. The housing hole size that holds the bearing is also important to prevent rattling between the bearing and the housing. The housing bore should typically be finished to a tolerance grade of about H7 for a clearance fit.

3. Heat Dissipation

Heat dissipation is especially important when the rotating shaft is under high loads and speeds. Bearing holders play a crucial role in dissipating heat generated by bearings to prevent overheating.

Other Information on Bearing Holders

How to Use Bearing Holders

Correct usage of bearing holders is key to maintaining bearing performance. Methods of mounting bearings, such as flange seizures, retaining rings, and free-running bearings, must be chosen based on the application:

• Flange Holder: Uses a flange to hold and fix the bearing axially. Suitable for applications where axial movement is undesirable.
• Retaining Ring: A groove in the housing holds a retaining ring to prevent the bearing from loosening. Used when axial force is minimal and slight axial movement is acceptable.
• Free-standing: No axial restriction, allowing free movement of the bearing. Typically used to support the free end of a ball screw.

What Are Filter Regulators?

Filter regulators are devices that combine an air filter and a regulator. They are essential in pneumatic systems to ensure clean and controlled compressed air supply. The air filter removes water droplets and dust, while the regulator adjusts the air pressure to a suitable level. These devices are commonly integrated into a single unit for convenience and efficiency in pneumatic circuits.

Applications of Filter Regulators

Filter regulators are crucial in maintaining the performance and proper operation of pneumatic equipment. They are used across various fields, including:

• Controlling the air flow in solenoid valves for precise operation.
• Ensuring clean and stable air supply in manufacturing facilities for semiconductors, integrated circuits, and precision machinery.
• Maintaining hygiene in medical facilities, food, and pharmaceutical production by preventing contamination from airborne particles.

Operating Principle of Filter Regulators

The principle involves two main functions: filtering and pressure regulation. The air filter section uses a high-performance filter to remove particulates and moisture from compressed air. Then, the regulator adjusts the pressure of the cleaned air to a consistent and suitable level for the downstream pneumatic equipment.

1. Air Filter

The air filter component uses deflection and a spiral motion to separate water and debris from the air, collecting them at the bottom of the cup. The filter element further removes fine particles.

2. Regulator

The regulator controls air pressure by balancing the force of a spring against the air pressure on the diaphragm, opening or closing the valve to maintain the set pressure level.

Selection Criteria for Filter Regulators

When selecting a filter regulator, consider the following factors:

• The specific application needs, such as liquid or gas filtration, pressure regulation, or flow control.
• The operating conditions, including temperature, pressure, and exposure to chemicals, to select suitable materials and designs.
• The nature of the fluid to be regulated, including its type, viscosity, and required pressure and flow rates.
• The importance of safety features, such as overpressure protection and ease of maintenance, for long-term operation.
• The balance between cost and performance, ensuring the device meets operational objectives within budget constraints.

What Is an HSS End Mill?

An HSS end mill is a tool used primarily for machining square metal or non-metal objects. Unlike a twist drill, which creates a circular hole, an end mill rotates and moves straight to enlarge a hole horizontally. End mills are made of two primary materials: HSS (high-speed steel) and cemented carbide. HSS end mills are common, while cemented carbide ones are better suited for cutting harder materials.

Uses of HSS End Mills

HSS end mills are employed as machining tools in milling machines. They are used for a variety of operations, including machining flat and side surfaces, grooves and pockets, chamfering, and mortising. This versatility enables them to be used in tasks like cutting out molds, forming gear keyways, and more. Given the wide range of tool types, each with unique features, it’s crucial to choose the most appropriate tool based on the specific machining requirements, such as the surface shape, depth, and dimensional accuracy.

Principle of HSS End Mills

HSS end mills comprise three main elements:

• Bottom Cutting Edge: The square end with a flat bottom is ideal for machining horizontal and side surfaces. The ball end, with a rounded bottom, suits curved surface machining. The radius end, an intermediate type, is best for R-machining and corner wall parts.
• Peripheral Flute: The ordinary blade is widely used, and suitable for a broad range of applications from roughing to finishing. The rafting blade, with a wavy shape, improves chip evacuation and reduces cutting resistance, making it ideal for roughing but less suitable for finishing. The tapered blade, with a tapered outer edge, is used for molding relief and inlays.
• Shank: Straight shanks are common, while long shanks are suitable for deep drilling. Long-neck shanks, with a partial neck, are useful for deep grooving, and tapered-neck shanks, with a tapered neck, are ideal for deep grooving near sloped walls.

What Is a Hair Net?

A hair net is a mesh cap designed to be worn inside a hair cap to prevent hair from falling out. Made from fine mesh, it effectively keeps hair and dander contained, minimizing contamination risks. The top part of the hair net features a coarser mesh for ventilation, reducing discomfort and stuffiness. Hair nets are available in both disposable and washable options.

Uses of Hair Nets

Hair nets are essential in environments where it’s critical to prevent hair from coming into contact with products or equipment, such as in food processing plants, precision equipment manufacturing plants, laboratories, and medical facilities. With the implementation of the revised Food Sanitation Bill in June 2020, which mandated HACCP (Hazard Analysis Critical Control Point) in the food industry, sanitation management has become even stricter. The HACCP system, a method for ensuring food safety by eliminating hazardous factors throughout the production process, now impacts a wide range of businesses involved in food manufacturing, processing, preparation, and sale. Consequently, hygiene control, including the use of hair nets, has gained increased importance, necessitating thorough training and adherence to manufacturing processes as per HACCP guidelines.

Principle of Hair Nets

Hair nets are typically donned at the start of the production process in food processing facilities. When worn correctly, they effectively cover the hair, ensuring proper hygiene. Key steps for correct usage include:

1. Tucking back the hair.
2. Turning the hair net inside out to check for foreign objects.
3. Positioning the hair net on the forehead, ensuring it is centered.
4. Securing the hair net over the head, making sure no hair protrudes.

The correct method involves turning the hair net inside out and securing it on the forehead before fully putting it on. This technique helps to keep the hair tucked in without disrupting its arrangement. Incorrectly wearing the hair net from the top can lead to hair protruding from the bottom, increasing the risk of contamination. Hair nets are widely used in various workplaces, and proper usage is critical. Risk reduction involves selecting the right size, ensuring hair is securely inside the net, and following any specific rules for removing and donning the cap.

What Is a Dewar Bottle?

A Dewar bottle is an insulated container that was commercialized by James Dewar in 1982. These bottles are the precursors to the commonly known “vacuum bottle” and “Thermos water bottle,” sharing similar structures.

A Dewar bottle has three distinctive structures that enable it to retain cold or heat for extended periods:

1. Two walls that make up the container
2. A vacuum layer between the two walls
3. The wall facing the vacuum layer blocks thermal radiation due to the reflection

Uses of Dewar Bottles

Dewar bottles are used to store liquids at extreme temperatures, ranging from minus 200°C to nearly 300°C. They are commonly used in chemical experiments, temporary refrigerant storage, and transportation. For instance, they are used in BAM (German Federal Institute for Materials Testing) thermal storage tests to measure the hazards of storing self-reactive substances. These tests often include protocols that utilize Dewar bottles.

Dewar bottles are typically made of stainless steel, but recent developments have led to the production of transparent glass Dewar bottles for observing container contents. They come in various types, including wide-mouth models for easy access and narrow-mouth models to minimize content evaporation.

Principle of Dewar Bottles

Dewar bottles function by utilizing a vacuum layer to block heat transfer, providing excellent thermal insulation. Heat transfer involves three principles:

1. Heat Transfer

Heat conduction occurs as molecules in motion at high temperatures transfer their energy to neighboring molecules to maintain equilibrium.

2. Convection

Convection involves the circulation and movement of gases and liquids as their molecular motion intensifies and density decreases when heated.

3. Thermal Radiation

Thermal radiation transfers heat through the transmission of electromagnetic waves.

In a Dewar bottle, the vacuum layer between the two walls prevents heat conduction and convection. To block thermal radiation, the inner surfaces of the walls are mirror-finished to reflect electromagnetic radiation, thereby maintaining the temperature inside the container.

Other Information on Dewar Bottles

Points to Note When Using Dewar Bottles

Due to past accidents with Dewar bottles, especially those storing liquid nitrogen, they should be handled with care. Important safety tips include:

• Do not put a lid on the Dewar bottle. Sealing a Dewar bottle containing liquid nitrogen can lead to an explosion due to air moisture freezing and blocking the gap between the bottle and the lid.
• Use leather gloves. Leather gloves are recommended when handling liquid nitrogen to prevent the gloves from sticking to your hands in case of spills.
• Be aware of your surroundings. If a Dewar bottle containing liquid nitrogen is knocked over, the rapid vaporization of the liquid nitrogen can displace air and pose a suffocation risk. Leave the room immediately or ventilate thoroughly in such cases. Also, check for any damage or cracks in the bottle after a fall.

What Is a Tape Switch?

A tape switch is a thin tape-shaped switch, also called a pressure-sensitive switch. It contains two thin electrodes, top and bottom, inside, and when force is applied in the direction of thickness, the contact points of the electrodes are connected and the switch is energized. In addition to its thinness, the length of the switch allows it to sense any position where it is pressed. Many of them have protrusions on the surface to facilitate response. A similar structure with a larger area is called a mat switch.

Some products are available in lengths from several inches to several feet and can be disconnected at any position by the user. Because of their wide detection range, they can be used for a variety of applications. Many products are thin and can be bent freely, making them suitable for curved surfaces. Lightweight, they can be easily attached with double-sided tape. Some products with waterproof treatment can be used in places where water splashes or outdoors.

Uses of Tape Switches

Since they can detect the passage of people and vehicles, they can be installed in corridors and window frames for security purposes.

In the case of emergency stop devices for factories and large facilities, they can be installed in areas that are dangerous to intrude into, and if the tape switches detect intrusion, it will stop the equipment. The low profile of the tape switches makes them unobtrusive even when installed in multiple locations. A similar application is the detection of doors, doors, automatic shutters, etc., for detecting pinching and opening/closing.

It can be installed on the bumper of an unmanned transport vehicle, for example, and used as an emergency stop device in case it comes in contact with something while in operation.

In hospitals and nursing homes, it is used to detect when a patient has gotten out of bed or other equipment. It can also be used to interlock tape switches with a nurse call, etc., to notify them. Since many products are bendable, they can be attached to curved surfaces, such as bed rails.

Can also be used as a foot switch for various devices. They are space-saving and convenient for multiple installations. Since the operating load can be selected, the ON/OFF sensing load can be selected according to the need for standing or sitting work, etc.

Principle of Tape Switches

The construction of tape switches consists of two electrodes, an insulator between the electrodes, and a vinyl outer covering (PVC or similar material) on the outside. To ensure strength, some switches are wrapped with nylon fiber between the vinyl exterior and the electrodes. Some products are made of vinyl with a vinyl exterior that is resistant to high/low temperatures and chemicals and can be selected according to the environment in which they will be used.

The principle of operation is that thin electrodes are placed on the top and bottom surfaces of the tape, and when a load is applied in the direction of the tape thickness, the thin electrode on the top surface curves to make contact with the electrode on the bottom surface, resulting in conduction. The two electrodes run from one end of the tape to the other, and can be placed on long surfaces because they can be activated by pressing any part of the tape except the ends. There are 2-wire and 4-wire types to choose from, depending on the application.

There are also mat switches with several tape switches inside a large mat-like sheet, which can detect a wide range of objects.

What Is Ceramic Tape?

Ceramic tape is a type of tape created from spun yarn, comprising ceramic fibers blended with a small proportion of organic fibers and reinforced with glass fibers. Ceramic, encompassing all manmade materials other than metal, wood, and plastic, is crafted by combining rocks, clay, and other minerals, followed by molding and baking. This tape offers greater heat resistance than fiberglass and is commonly employed as a heat insulator in high-temperature environments, such as in boiler and pipe insulation.

Uses of Ceramic Tapes

Due to its remarkable heat resistance, ceramic tape finds its application in areas with high temperatures, including use in shut-off curtains, pipe insulation, and combustion work. It is specifically utilized for lagging boilers and pipes, insulating piping and exhaust ducts, furnace curtains, heat treatment slow cooling covers, welding spark prevention, and heat-resistant packing. Ceramic tape is also employed for filling brick expansion allowances, sealing furnace doors, covering heat-resistant water hoses, muffler insulation in internal combustion engines, blocking radiant heat, and burn prevention.

Characteristics of Ceramic Tapes

Composed of spun yarn with ceramic and organic fibers, and reinforced with glass fibers, ceramic tape exhibits outstanding heat resistance and flexibility. It serves as an asbestos alternative, being ideal for heat, sound, and cold insulation, particularly in high-temperature settings. Relative to silica cloth and alumina tapes, it is more cost-effective.

Amorphous ceramic fiber (refractory ceramic fiber/ RCF) is regulated under RCF regulations, necessitating specific measures like usage notification, working environment assessments, special control substance measures, chief worker appointments, and special health checkups. However, products not using RCF, and thus not subject to these regulations, are available. These non-RCF products use bio-soluble fiber (BSF) as the primary material, with glass fiber, SUS wire, Inconel wire, and organic fibers like rayon as reinforcement, instead of RCF.

What Is a Sprew?

A sprew is a part designed to reinforce female threads by coiling a diamond-shaped stainless steel wire around them. Utilizing the spring back effect of the wire significantly enhances the accuracy of screw fastening. By correcting lead and angle errors of the threads, stress is evenly distributed throughout the length of the threaded hole, thus strengthening the connection between the base metal and the screw.

Uses of Sprews

Primarily, sprews are employed to reinforce female threads, especially in materials like light metals, cast iron, and plastics, where the native threads may be weak. The use of sprews to create a rolling female thread of stainless steel equalizes stress distribution, thereby enhancing the fastening force and ensuring a more secure screw attachment.

Sprews also improve the durability of female threads against wear, corrosion, vibration, and heat, protecting the base material and ensuring reliable thread fastening. Furthermore, they are utilized for repairing defective female threads, easily restoring stronger threads than the original ones.

Additionally, sprews contribute to reducing the diameter of male threads and the length of female threads, which results in lighter and more compact products, lowering manufacturing costs and enhancing product quality.

Principle of Sprews

Sprews are particularly effective in reinforcing products made from low-strength materials like aluminum or plastics, preventing thread breakage and enhancing durability. A special tap is used for setting the threads of a sprew, which is characterized by its free outside diameter – the diameter of the sprew before insertion, typically 15% to 20% larger than the insertion diameter.

The structure of a sprew includes the free turns (number of turns in its free state), the first coil (which guides and twists into the tap groove hole), the tongue (the part twisted in with an insertion tool), and a notch (used for folding out the tongue in through-hole applications).

As industrial products evolve to become smaller and lighter, the importance of materials and structures in design and manufacturing increases. Sprews play a vital role in addressing issues like wear, fracture, and galling in weaker or brittle base materials such as light alloys, nonferrous metals, and various plastics, thus preventing common problems in these applications.

What Is a Side Cutter?

A Side Cutter is a type of cutting tool used on a machine tool. It has cutting edges on the outer circumference and both sides, and is also called a side milling cutter.

In addition to regular blades, there are other blade shapes such as rough blades and staggered blades. Metal saws are similar to side cutters, but they have cutting edges only on the outer circumference, and their blade shapes include regular and rough edges.

Side Cutters are used for machining flat surfaces, slots, and other shapes. These cutting machines are also suitable for machining edges and corners. They are used not only for metalworking but also for cutting wood and plastics. They are also used in various manufacturing fields such as automobiles, aircraft, and home appliances, and are indispensable for determining the shape of products.

Uses of Side Cutters

Side Cutters are used as cutting tools for groove cutting, step cutting, side cutting, width determination, and grooving. Since side cutters have cutting edges on both sides, the width dimension of the cutting edge is the largest, and the main body of the cutter is smaller than that of a metal saw.

The width of the cutting edge is smaller than that of the metal saw, and the thin width of the main body allows the sides of the groove to be finished cleanly without the sides of the main body rubbing against the sides of the workpiece, even when the depth of cut is large. Therefore, it is particularly suitable for groove machining.

It is also used in industrial machines, where a high-speed rotating blade can cut materials. They may be equipped with a device to hold the material in place and an automatic feeder.

Widely used for processing metals and plastics, side cutters play an important role in the manufacturing and construction industries.

Principle of Side Cutter

Side Cutters hook the material to the blade and cuts the material with the rotating blade. Mainly used as a manual tool, the side cutter holds the material to be cut by gripping the handle, and cuts it by hooking the blade onto the material and rotating it.

The blade is angled to cut the material, and clean cutting is possible by applying the appropriate force to the material.

Types of Side Cutters

There are three types of side cutters: Down Cutter, Up Cutter, and Flywheel.

Side Cutters have common properties that the cutter size, pitch, and position are selected so that at least one cutting edge always bites into the cutting area.

1. Down Cutting

The jig and arbor support must be strong enough to withstand the resistance of the milling process. The most recommended machining method is the downcut method, which prevents the workpiece from being forced downward toward the table by the principal force. The downward force causes the feed direction to be in the same direction as the cutting resistance. 

2. Upcut

Upcut is an alternative machining method for cases where insufficient rigidity causes problems or when machining new work material. This method can be used to solve problems caused by insufficient rigidity of the setup or by chip jamming in deep grooves.

3. Flywheel

Flywheel is an excellent complementary machining method for cases with insufficient setup rigidity and low machine power and torque. The best solution is to install the flywheel as close to the tool as possible and to mount the workpiece more securely.