As a leading player in the bearing industry, RHD’s motor bearing series has below outstanding features:
1. P4/ABEC 7 and P2/ABEC 9 precision:
With the emergence of new materials like rare earth permanent magnet Nd-FE-B and magnetic composite materials, more and more high-performance motors are appearing on the market. That also results in a great demand of top quality bearings. Since adopting dedicated cages and precise processing, the friction factor can be decreased significantly and therefore enhancing the rotating speed and service life. Such bearings are widely used for simplifying motors’ structures, reducing motors’ dimensions, stabling the operational condition and finally increasing the finished products’ precision and stability. Presently there are P5/ABEC 5 and P6/ABEC 3 bearings flooding on the market, but RHD is always pursuing higher levels. With 30 years experiences in bearing industry, RHD is focusing on the market demands and industrial trends, run through thousands of experiments, and successfully optimized the bearing’s construction and developed related rolling elements, ditch curvature, superior light cages and great lubricating capability. By employing the most advanced techniques, RHD now is able to apply P2/ABEC 9 and P4/ABEC 7 production, fully achieving world-class standards.
2. 20dB-30dB low-noise secures world-class operating condition:
Bearings are mainly applied for reducing the frictions generated during mechanical operation. Under a high-speed rotating condition, the frictions among rings and rolling elements and per se will bring about serious working noises. For instance, the noise generated by a dental handpiece is usually around 70dB which possibly cause damages to the hearing. Generally speaking, voice between 20dB-30dB is usually called as “silence” and under 28dB should be very difficult to hear from 1.5 meters away. The noise generated also reflect the bearings’ operating condition, from a professional prospective, the “bearing noise” is the sound effects directly or indirectly generated by the vibration of bearing and its connected elements. While a radial pressure loaded on a bearing, the subjected rolling elements will be regularly switched between 2-3-2-3…during the operation. Such switches will bring deviation of loading directions and thus lead to the vibration. Therefore, many engineers consider the noise problem as an overall vibrating problem. To solve the difficulties, the bearings’ precision, rotating speed, materials, lubricant, precision and structure have to be developed under stringent controls. RHD’s motor bearing series now is able to stably stay in 20dB-30dB at 60,000 rpm, and even can achieve 17dB standard for customized products.
3. Dedicated 60,000 rpm rotating speed:
Built-in integrated spindle and motor now is widely used for high speed machine tools, also named as the electrical spindle. Electrical spindle certainly is a better structure for most professional equipments, and thus its performance will directly affect the overall capabilities of the machines. In other words, if we can’t fit great bearings for spindle to achieve superior coupling, the equipment will be lack at the precision, speed and so on. The components of electrical spindle normally are corrected at “μm” class, such as the 1~3 μm vibration and 100-300N/μm rigidness. Adhering with such precision, errors of accuracy and deformation should be limited within a very small range. However, the friction of rotating will bring serious temperature heat distortion to the bearing’s preload condition, and may lead to heat engaging and subsequently bring huge damages on the spindles. This issue significantly reduces the reliability of bearings used in the actual production process. The bearing’s maximum speed under natural working order thus comes to a crucial position if higher performance spindle needed. Through 103 strict procedures, RHD’s motor bearing series is fully able to withstand the heat generation under maximum 60,000 rpm speed operation at 20-30dB over 18 months. If there is no restriction on the working noise, the maximum speed can be enhanced to 480,000 rpm.
4. Finest military high carbon chrome bearing steel – ZGCr15:
If quality is the keyword of top class bearings,then material should be the base of quality. Without excellent materials, there would be no chance to achieve first class manufacturer in the world. According to the surveys, the most common materials on the market presently are bearing steel, stainless steel and ceramic. The bearing steel contains carbon element at 0.95% to 1.1%, by mixing Cr, Mn and other elements, it requires pheroidizing annealing process and need to be quenched (around 840 ℃) and tempered (150 ℃) before usage. The stainless steel is often mixed with Ni,Mo,Ti,Nb,Cu,N and other alloy elements for various uses, but the Co content is normally over 10.5%. In contrast with former two materials, RHD adopts military high carbon chrome bearing steel (ZGCr15) which contains particular low oxygen composition. We also take strict controls on harmful composition such as P and S, etc. To cast ZGCr15, we need to run through the latest improved electroslag remelting techniques, purifying the metal contents into pure and compact structured steel ingots. Its high consistency, fine and even granular crystals greatly improve the mechanical properties, assist the bearings be able to withstand very heavy loads and deformation-resistance, subsequently make the bearings’ service life significantly longer.
5. Top Textolite-based phenolic Cage:
Different brands of bearings use different cage materials. RHD bearing adopted the textolite-based phenolic material which could only be provided by few suppliers in the world. By adopting textolite-based phenolic cage, plus P4/ABEC 7 precision,our bearing can reach 60,000rpm rotating speed at 20-30dB. The material also has the following properties, such as high temperature resistance, corrosion-resistance, self-lubrication, and so on.
