This section provides an overview for pillow blocks as well as their applications and principles. Also, please take a look at the list of 10 pillow block manufacturers and their company rankings.
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A pillow block is a bearing unit that houses bearings. They are installed in various machines by being mounted to sandwich bearings and rotating parts from both sides. They are mainly made of metal and vary in shape and material depending on the uses of the machine and the surrounding environment. These devices are used to protect the interior from rain, wind, and temperature, and are incorporated into not only large equipment but also commonly used transport machines. In recent years, development of pillow blocks that can handle high-speed rotation and high loads has been progressing.
Pillow blocks are used to protect bearings and rotating parts. Many machines incorporate rotating parts such as gears and motors, which require bearings to support them and pillow blocks to protect these two parts. Rain, wind, and dust can affect the rotational motion, especially when installed outside. Pillow blocks are used to minimize external influences. They are also used to prevent high temperatures and increased loads associated with high-speed rotation.
Pillow blocks are installed to protect the rotating elements and bearings, and they come in a variety of shapes depending on their application. Here are some of the principles and features of the pillow blocks.
Both pillow blocks and plummer blocks are bearing cases, but there are major differences. One is whether only the bearings can be replaced. In most cases, pillow blocks have a structure of two pieces that can be separated and the bearing itself can be taken in and out of the case. Plummer blocks, on the other hand, have the bearings fitted into the case, so basically all of them need to be replaced. What is obvious from this difference is the cost aspect. In the case of pillow blocks, the case can continue to be used as is if the internal bearings are replaced (except in the case of major damage), but in the case of plummer blocks, the entire case must be replaced, so the cost of the case is incurred for each replacement.
In terms of maintenance, there is no significant difference between the two types of bearings, since the shaft needs to be pulled out once when replacing a bearing. However, there is a big difference when you want to check the condition of the bearings. In the case of pillow blocks, the bearings can be visually checked by opening the upper case. In the case of plummer blocks, the condition of the bearings cannot be checked as easily as with pillow blocks because of the need to pull them out of the case.
Some pillow blocks and plummer blocks come with grease nipples for greasing the bearings, while others do not. This depends on the type of bearing. For grease-filled type bearings, which are pre-filled with grease inside, there is no need to grease up the bearing after installation. For this reason, there is no nipple attached to the case. On the other hand, it is important to remember to grease up the non-encapsulated type.
The materials used for pillow blocks are cast iron and spheroidal black smoked cast iron. Since both are cast iron, they are vulnerable to impact and break easily, so they must be handled with care. For larger pillow blocks, the bolts are also larger, and high-strength bolts such as SCM435 are used to ensure higher bolt strength. Since bolts loosen due to vibration, periodic loosening checks and retightening are necessary. Care must be taken not to break the pillow blocks by over-tightening.
*Including some distributors, etc.
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