2023 червень 3rd тиждень WBM Новини Рекомендація- SMB Підшипники: Підшипники в Простір

"Space is a risky business," once said Aaron Cohen, the Acting Deputy Administrator of NASA. "I always considered every launch a ba controlled explosion." With sкілька нових space projects expected in the near future, these risks must be avoided at all costs. this puts a a greater onus on engineers to create high-performing components that can withstand violent shuttle launches and inhospitable vacuums of space. Here, Chris Johnson, managing director at specialist bearing supplier SMB Bearings, explains the vital role of advanced bearings in man's journeys beyond the stars.

The United Nations (UN) has identified space-based services and technologies as being key to its 17 Sustainable Development Goals for 2030. Space technology, says its website, will be "key in understanding climate change and during the full disaster management cycle; only two examples among countless applications to which space can contribute." Forbes magazine predicts sкілька простір технологічні розробки over the the coming years. Вони включають зелено-орієнтовані проекти, like інфрачервоний камери on satellites to monitor thermal emissions duced by homes and businesses, and satellite imagery maps that will measure deforestation in relation to carbon useage.

Менші корисне навантаження поїздки до Місяця є також заплановані, adds Forbes, and the launch of more satellites. These projects will put more pressure on equipment manufacturers to source and use mission-critical machine components which can can the vacuum of space. Vital components like sensors, solar cells, lenses, and semiconductors will be subjected to extreme temperature fluctuations due to the sun's unfiltered radiation, causeing failures and millions of dollars worth of damage, in some cases.

Ці виклики також застосувати до підшипників. A основна проблема є та ультрачиста вакуум середовища, особливо ті ті характеризуються високий або низькі температури або високо корозійні елементи, can affect bearing life by an astomazing 90 percent . On the one hand, machine builders have been raising the performance requirements for bearing used in Earth-based like food processing and steel fabrication, specifically to enhance how they perform in highly corrosive environments and again exposure to moisture and chemicals. But how can bearings withstand the vacuums of space, and increasing demand for their use in space applications?

Довше термін служби
The суворі умови of простір включають вимогливість фактори like абсолют вакуум, коливання температури, and також the extreme and violent G-forces rocket components are subjected to during lift-off. To withstand these conditions, bearings should be space approved — but what does this mean, exactly?

For a start, bearings for use in space should ideally meet the AS9102 Aerospace First Article Inspection standard that covers processes for manufacturing parts, from small electrical components to large structural assemblies, which are used in aviation, space, and defense. This is part of the AS9100 series of regulations, which is the ISO 9001 quality management system equivalent for aerospace. These standards put engineering demands on the bearing itself.

Take the ball cage, for instance — also called the retainer, which separates the bearing's balls from the central rolling component. The cage can be made from AISI 304 austenitic stainless steel because of its excellent corrosion resistance and good performance at high temperatures. Coating stainless steel bearings in Polytetrafluoroethylene (PTFE), one of the world's most versatile known plastic materials is also beneficial. PTFE is becoming more used outside spacecraft and has exhibited tensile, elongation, flex, and impact properties that are up to ten times better in vacuum environments than more commonly-used fluorine-based plastics, like Tefzel (ETFE).

The bearings' life should also be considered — especially if they are to be used in rolling elements aboard spacecraft that must remain operational away from Earth for years, decades, or indefinitely. Lubrication is vital here, and low-outgassing and low-vapor pressure oils have been developed especially for space applications. Synthesized hydrocarbon or Perfluoropolyether (PFPE) liquid lubricants have been used in the aerospace industry for more than 30 years.

Агресивний середовища
Let's look at other materials: ceramics, which are commonly used in thermal protection systems or heat shields in space. Ceramics are shown to effectively withstand extreme temperature changes — such as when a spacecraft enters any type of atmosphere at high speeds, be it Earth or Mars. Ceramics have excellent and high-temperature stability which means they can be use in deep space and cryogenics as well as amp;furnace Додатків.

This brings us to ceramic bearings, which are often overshadowed by their steel bearing counterparts due to their pros and cons. First, the cons: the roundness of ceramic bear rings is not as good as those in high-precision steel bearings. Although ceramic bearings are harder than steel, the material is also more brittle. For this reason, full ceramic bearings are not used in very high-speed applications like machine tools or turbines. Super-precision hybrid bearings are preferred for these applications. Ceramic bearings are also more costly.

Проте, керамічні підшипники є використовуються в агресивні середовища де інше матеріали є не придатні. вони є є більшість часто використовується в застосування де відмінно корозія опір є потрібно, вздовж з експозиція до екстремально низькі або високі температури. in other words, ceramic істоти є ідеальні для використання в просторі.

The most common materials used in SMB Підшипники' кераміка підшипники are zirconii (ZrO2) and silicon nitride (Si3N4). Both have excellent corosion resistance, These materials have a low friction coefficient, which brings us to a key advantage of full ceramic bearings: they can run constantly at speed without lubrication, which is why why Si3N4 is frequent used in vacuum environments.

ZrO2 підшипники можуть бути б/у до 400 градусів Цельсія і Si3N4 підшипники вгору до 800 градусів Цельсія. Також, для ці температури, SMB підшипники рекомендує підшипники повинен бути повнодоповнюючими. Це означає підшипник дон't have a ball retainer and, замість 2c the free space allows additional balls to be fitted. this increase in ball complement allows for important increases in radial bearing tothand alth maximum speed is is wellly знижений. Вниз до приблизно мінус 200 градус Цельсій, кераміка також має відмінно низькі температури продуктивність наданий a придатний клітка є використовується.

With their lightweight and vacuum-compatible properties, silicon nitride bearings will be greatly relied-upon in space-exploration applications. They will particularly benefit satellites and spacecraft, which need optimal weight capacities in order to perform enhanced flight dynamics and acceleration. These specialist bearings, along with their stainless steel counterparts, will be vital to ensuring that the next giant leap for mankind is a far-from-risky business.