The properties of concrete include the workability of concrete mixes, concrete strength, deformation and durability. Workability, also known as workability, means that the concrete mix is ​​easy to operate under various construction conditions under certain construction conditions to ensure uniform and compact concrete performance. Workability is a comprehensive technical indicator that includes three main aspects of fluidity (consistency), cohesiveness and water retention. Strength is the main mechanical property of concrete after hardening, reflecting the ability of concrete to resist load. Concrete strength includes compression, tensile, shear, bending, flexural and grip strength. Among them, the compressive strength is the largest and the tensile strength is the smallest. Deformation of concrete includes deformation under non-loading and deformation under load. The deformation under non-loading has chemical shrinkage, dry and wet deformation, and temperature deformation. If the amount of cement is too much, chemical shrinkage is likely to occur inside the concrete to cause fine cracks. Concrete durability refers to the ability of concrete to resist various destructive factors under actual use conditions and maintain strength and appearance integrity for a long time. Including the frost resistance, impermeability, corrosion resistance and carbonation resistance of concrete.
NSK manufacture a full range of deep groove ball bearings. These bearings are the most common type and are used in a wide variety of applications. Nsk Bearing,High Temperature Bearings,Nsk Ball Roller Bearings,Nsk Ball Bearing Shijiazhuang Longshu Mechanical & Electrical Equipment Trading Co., Ltd. , https://www.longsbearing.com
Single-Row Deep Groove Ball Bearings
Pressed Steel Cages
Single-row deep groove ball bearings are the most common type of rolling bearings. Their use is very widespread.
In addition to open type bearings, these bearings often have steel shields or rubber seals installed on one or both sides and are prelubricated with grease. Also, snap rings are sometimes used on the periphery. As to cages, pressed steel ones are the most common.
For big deep groove ball bearings, machined brass cages are used.
Machined cages are also used for high speed applications.
Extra Small Ball Bearings and Miniature Ball Bearings
Miniature and instrument ball bearings can be divided into two basic types, deep groove and angular contact. The first (deep groove) can be further divided into the following five classes depending on their design details:
Standard type
Flanged outer ring
Extended inner ring
Expanded type in which one ring has a radial thickness that is larger than normal compared with the bearing width.
Thin section type in which both rings are extra thin in the radial direction. They can also be classified as: open, shielded, or sealed.
Maximum-Type Ball Bearings
Maximum-Type ball Bearings contain a larger number of balls than normal deep groove ball bearings because of filling slots in the inner and outer rings. Because of their filling slots, they are not suitable for applications with high axial loads. types of bearings have boundary dimensions equal to those of single-row deep groove ball bearings of Series 6200 and 6300 respectively. Besides the open type, ZZ type shielded bearings are also available. When using these bearings, it is important for the filling slot in the outer ring to be outside of the loaded zone as much as possible. Their cages are pressed steel.