Ningbo Kent Bearing Co., Ltd

High‑temperature Bearing   Conventional bearings depend heavily on sealing rings to achieve tight sealing. High‑temperature bearings rarely use standard contact rubber seals; labyrinth non‑contact seals are widely applied, and some only feature basic dust‑proof treatment. The rubber seals of conventional bearings tightly fit against the inner and outer rings by material elasticity to block dust and moisture. However, general‑purpose polymer sealing materials such as nitrile rubber have limited temperature resistance. Once exceeding the critical temperature, they will rapidly harden, crack and lose elasticity. The seals fail first, and fallen debris may intrude into the bearing interior and cause secondary contamination. Fatal Drawbacks of Contact‑Type Seals under High‑Temperature Working Conditions   01 The material has an insufficient maximum temperature resistance, and cannot match the continuous‑operation environment of high‑temperature bearings, leading to aging and failure within a short period.。 02 The sealing lip generates continuous heat through friction. This heat can be negligible at ambient temperature. However, in high‑temperature environments, the additional temperature rise accelerates grease oxidation and deterioration, greatly shortening the service life of the bearing.。     In short: under high‑temperature working conditions, rubber sealing rings fail to deliver long‑term protection; instead, they become hidden hazards that accelerate bearing damage.   KENT Bearing’s solution is to adopt labyrinth‑type non‑contact seals. Tortuous clearance channels are formed between the inner and outer rings. Impurities are blocked from intrusion via these labyrinth paths, and protection is achieved without material contact. Free of frictional heat generation and rubber heat‑resistance bottlenecks, dust‑proof performance is realized by mechanical structure rather than rubber elasticity. For ultra‑high‑temperature applications with clean surroundings, open‑type structures combined with external protective shields are also adopted for joint protection. Under such conditions, temperature rise and material aging risks caused by full sealing far outweigh the threat of impurity ingress.   Every structural trade‑off for high‑temperature bearings comes from repeated evaluation against actual working conditions. Seemingly “simplified” sealing solutions are in fact professional designs tailored for high‑temperature environments. When selecting bearings, do not merely refer to parameter tables. Understanding the matching logic between working conditions and structures is the key to stable and durable solutions.   With over 20 years of dedication to the bearing industry, KENT Bearing keeps investing in core‑technology research and has built distinct product advantages. Compared with peers, our products not only meet strict noise‑reduction requirements across multiple industries, but also satisfy customers’ core demand for long service life with genuine quality and outstanding durability.

As a motor manufacturer, have you ever encountered batch‑rework issues caused by premature bearing failures, or lost high‑end orders due to excessive noise?   The root cause often lies in the fine details of the sealing structure. The choice between ZZ and 2RS is essentially a matter of working‑condition matching.   The ZZ type double‑sided metal dust shield adopts a non‑contact design with extremely low friction torque, making it inherently suitable for high‑speed motors. By contrast, the 2RS type rubber seal delivers superior sealing performance; however, its contact‑type friction will limit rotational speed and raise temperature rise. It is better suited for low‑speed heavy‑duty applications or heavily contaminated environments.   An agricultural motor manufacturer’s products have long been deployed in dusty, humid field‑working environments. Initially, ZZ‑type bearings were adopted. Although the rotational‑speed requirements were met, a large number of seizure failures occurred within half a year caused by water and dust ingress, with a rework rate as high as 18%.   The root cause was that the non‑contact structure of ZZ shields could not resist the intrusion of moisture and fine dust. Condensation and rust tended to form inside the bearing, especially under large temperature fluctuations during start‑stop cycles.   We recommended switching to KENT‑produced 6202‑2RS bearings. The double‑sided rubber seal of the 2RS adopts an interference‑fit contact design to create a physical barrier, effectively blocking mud‑water, dust and moisture.   Meanwhile, KENT optimized the aging‑resistance performance of the rubber material as well as lip pressure distribution. While maintaining reliable sealing performance, the friction torque is kept within a reasonable range to avoid excessive speed limitation.   After the replacement, the motor failure rate dropped below 2% under the same harsh working conditions. The customer commented: “It keeps working well even when exposed to rain”. Although 2RS seals are not suitable for ultra‑high‑speed applications, their protective value is irreplaceable in low‑speed, heavy‑duty and heavily‑polluted scenarios.  

Kent Bearing   A follower commented and asked: “How do you tell if a bearing manufacturer is reliable?” Having run a bearing factory for over 20 years, here is my take: look past the quotation and focus on three key details.   First, check testing capabilities. A credible manufacturer must have its own in‑house laboratory capable of spectrum analysis, metallographic examination and noise testing, instead of merely relying on test reports supplied by raw‑material vendors.   Second, assess process consistency. Find out whether grinding operations are carried out on CNC equipment and whether assembly takes place in a dust‑free workshop. These factors directly determine bearing batch‑to‑batch consistency.   Third, evaluate technical responsiveness. When you raise special requirements, see if the supplier makes excuses or proactively arranges engineers to work out solutions together.   Last year, a servo‑motor manufacturer approached Kent Bearing. They required bearings to run below 35 dB at 8000 RPM. Many factories simply replied “it cannot be done”. We, however, spent two weeks modifying cage materials and heat‑treatment processes. The final delivered product measured 32 dB in actual testing. We also helped them optimise the fit tolerance for motor end covers. A truly reliable bearing manufacturer will not hide behind “industry standards” as an excuse; instead, it is willing to invest R&D resources to match your requirements. Furthermore, a word for motor manufacturers: sourcing a trustworthy supplier is not a one‑off transaction, but building long‑term collaborative partnership. A good bearing supplier does not just sell components. It understands your motor design parameters, load characteristics and application scenarios, and helps turn bearings from ordinary spare parts into performance enablers.   Kent Bearing once co‑developed custom‑built bearings with an industrial drone‑motor manufacturer. We joined testing from the prototype phase and jointly solved the problem of grease throw‑off under high‑speed operation. The end product achieved 30 % longer service life than competing solutions and became one of their core selling points.