Monday, 16 January 2017
Mbp Bearings has published a new research study titled “Plastic Bearings Market – Growth, Share, Opportunities, Competitive Analysis and Forecast, 2015 – 2022”. The Plastic Bearings market report studies current as well as future aspects of the Plastic Bearings Market based upon factors such as market dynamics, key ongoing trends andsegmentation analysis.Apart from the above elements, the Plastic Bearings Market research report provides a 360-degree view of the Plastic Bearings industry with geographic segmentation, statistical forecast and the competitive landscape.
Geographically, the Plastic Bearings Market report comprises dedicated sections centering on the regional market revenue and trends. The Plastic Bearings market has been segmented on the basis of geographic regions into North America, Europe, Asia Pacific and Rest of the World (RoW). The RoW segment consists Latin America and the Middle East & Africa. The Plastic Bearings market has been extensively analyzed on the basis of various regional factors such as demographics, gross domestic product (GDP), inflation rate, acceptance and others.Plastic Bearings Market estimates have also been provided for the historical years 2013 & 2014 along with forecast for the period from 2015 – 2022.
The research report also provides a comprehensive understanding of Plastic Bearings market positioning of the major players wherein key strategies adopted by leading players has been discussed. The Plastic Bearings industry report concludes with the Company Profiles section which includes information on major developments, strategic moves and financials of the key players operating in Plastic Bearings market.
Geographically, the Plastic Bearings Market report comprises dedicated sections centering on the regional market revenue and trends. The Plastic Bearings market has been segmented on the basis of geographic regions into North America, Europe, Asia Pacific and Rest of the World (RoW). The RoW segment consists Latin America and the Middle East & Africa. The Plastic Bearings market has been extensively analyzed on the basis of various regional factors such as demographics, gross domestic product (GDP), inflation rate, acceptance and others.Plastic Bearings Market estimates have also been provided for the historical years 2013 & 2014 along with forecast for the period from 2015 – 2022.
The research report also provides a comprehensive understanding of Plastic Bearings market positioning of the major players wherein key strategies adopted by leading players has been discussed. The Plastic Bearings industry report concludes with the Company Profiles section which includes information on major developments, strategic moves and financials of the key players operating in Plastic Bearings market.
Wednesday, 11 January 2017
The bearing is an essential part of the machinery which helps to reduce the friction of motion and increases the smoothness of machine. Bearings are widely used in the automotive industry which helps to increase the speed of a vehicle. Bearing reduces the friction between fixed and moving machine parts. However, it requires consistent maintenance to prevent early failure. The desperate need for energy-efficient vehicles and the expanding demand for bearings from the defense and aerospace industry increase the importance of bearing.
The bearing market is mainly driven by growing automotive market across the world. Strong growth of the automotive sector in Asia-Pacific region is expected to further drive the demand for bearing market through the forecast period. The rising demand across various application sectors such as industrial, railways and aerospace sector is expected to witness a substantial growth during the forecast period. Development of seal technologies, lightweight elements in high-performance bearings and lubrication technologies gives some market growth opportunities.
The report covers forecast and analysis for the bearing market on a global and regional level. The study provides historic data of 2014 along with a forecast from 2014 to 2020 based on revenue (USD Billion). The report also offers the detailed competitive landscape of the global bearing market. It includes company market share analysis, the product portfolio of the major industry participants. The report provides detailed segmentation of the bearing market based on product, application segment and region. On the basis of product, the global bearing market is segmented into ball bearing, plain bearing, and roller bearing. The ball bearing product segment of bearing market is the fastest growing segment of bearing market through the forecast period due to its advantages like smaller surface contact and less friction.
Automotive, agriculture, electrical, mining & construction, railway & aerospace and other applications are the key applications involved in the bearing market. Bearing applications in motor vehicles that are automotive held the highest revenue share in 2014. Major regional segments analyzed in this study include North America, Europe, Asia-Pacific, Latin America, and the Middle East and Africa. This report also provides further bifurcation of a region on the country level. Major countries analyzed in this reports are U.S., Germany, France, UK, China, Japan, India, and Brazil. Asia Pacific was the dominating region in the global market of bearing in 2014 due to the booming automobile industry in this region. Asia Pacific is followed by Europe and North America.
The report covers detailed competitive outlook including company profiles of the key participants operating in the global market. Key players profiled in the report include Mbp Bearing Pvt. Ltd,
Global Bearing Market: Product Segment Analysis
Ball bearing
Plain bearing
Roller bearing
Global Bearing Market: Application Segment Analysis
Automotive
Agriculture
Electrical
Mining & Construction
Railway & Aerospace
Others
Global Bearing Market: Regional Segment Analysis
North AmericaU.S.
EuropeUK
France
Germany
Asia PacificChina
Japan
India
Latin AmericaBrazil
The Middle East & Africa
Tuesday, 10 January 2017
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.
Ball bearings tend to have lower load capacity for their size than other kinds of rolling-element bearings due to the smaller contact area between the balls and races. However, they can tolerate some misalignment of the inner and outer races.
The three primary principles of maximising bearing life are: selecting the correct lubricant, applying the lubricant properly, and maintaining the lubricant in a clean condition. Neglect or failure in any of these three areas will seriously increase the risk of premature bearing failures and will interfere with trouble-free running.
The increased speeds and higher temperatures at which modern bearings routinely operate, combined with the demands placed upon them for improved accuracy and reliability, mean that the process of selecting a suitable bearing lubricant today, is more critical than ever. Correct selection of a lubricant:
Bearing lubricants fall into three main categories: oils, greases and solid dry film lubricants, which are usually limited to moderate speed and very light loading conditions. The selection of a particular type of bearing lubricant is generally governed by the operating conditions and limitations of a bearing system. Factors include:
Grease considerations
The primary advantage of grease over oil is that bearings can be pre-lubricated, eliminating the need for - and the cost of - an external lubrication system. Besides simplicity, grease lubrication also requires less maintenance and has less stringent sealing requirements than oil systems. Grease tends to remain in proximity to bearing components.
The drawbacks of using grease are that it does not conduct heat away from a bearing as efficiently as oil. Also, grease can increase the initial torque within a bearing and cause running torque to be slightly higher. The speed limits for greases (expressed as an ndm value, with ndm being the rpm multiplied by the bearing PCD in mm) are generally lower than for oils due to the plastic nature of grease that tends to cause overheating at high speeds.
In certain applications the design of the bearing and the selection of a suitable grease become very challenging. Here, it is critical that the bearing supplier has the knowledge and experience to suggest a grease that ensures maximum reliability of the bearings over long operating periods without re-lubrication. Current "greased-for-life" bearing technology can consistently give 30,000+ hours of life at 700,000 ndm.
Oil considerations
While grease lubrication is inherently simpler than lubrication with oil, there are still applications where oil is the better choice. In high-speed spindle and turbine applications, for example, oil is supplied continuously and provides cooling as well as lubrication. A further example is instrument bearings with extremely low values of starting and running torque. These require only a minimal, one-time lubrication, each bearing receiving just a few milligrammes of oil.
The limiting speeds for oil-lubricated bearings are governed by the size of the bearing and the design of the cage, rather than by the lubricant itself. To illustrate this, petroleum or diester-based oils can accommodate bearing speeds of up to 1,500,000 ndm or higher. In the case of silicone-based oils, the maximum speed rating drops to 350,000 ndm. Similarly, when calculating life for bearings lubricated with silicone-based oils, the Basic Load Rating (C) should be reduced by two-thirds (C/3). To ensure long life at high speeds, the lubrication system should provide for retention, circulation, filtration and possibly cooling of the oil.
In extremely harsh operating environments such as dry pump bearings, often oil selection is pre-defined to a certain extent by the end user. In dry pumps, the challenge for the bearing supplier is to optimise the design of the bearings in order to make the best use of relatively poor lubrication.
Solid soft film lubricants
Solid soft films are primarily used to provide solid lubrication for bearings in extreme applications where traditional fluid lubricants would be rendered ineffective. They offer the advantages that their friction is independent of temperature, and they do not evaporate or creep in terrestrial vacuum or space environments.
The solid soft film lubricant can either be applied directly to the surface or transferred by rubbing contact from a sacrificial source such as a self-lubricating bearing cage.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.
Ball bearings tend to have lower load capacity for their size than other kinds of rolling-element bearings due to the smaller contact area between the balls and races. However, they can tolerate some misalignment of the inner and outer races.
The three primary principles of maximising bearing life are: selecting the correct lubricant, applying the lubricant properly, and maintaining the lubricant in a clean condition. Neglect or failure in any of these three areas will seriously increase the risk of premature bearing failures and will interfere with trouble-free running.
The increased speeds and higher temperatures at which modern bearings routinely operate, combined with the demands placed upon them for improved accuracy and reliability, mean that the process of selecting a suitable bearing lubricant today, is more critical than ever. Correct selection of a lubricant:
- Reduces friction and wear by providing an elasto hydrodynamic film of sufficient strength and thickness to support the load and separate the balls from the raceways, preventing metal-to-metal contact.
- Minimises cage wear by reducing sliding friction in cage pockets and land surfaces.
- Prevents oxidation/corrosion of the bearing rolling elements.
- Acts as a barrier to contaminants.
- Serves as a heat transfer agent.
Bearing lubricants fall into three main categories: oils, greases and solid dry film lubricants, which are usually limited to moderate speed and very light loading conditions. The selection of a particular type of bearing lubricant is generally governed by the operating conditions and limitations of a bearing system. Factors include:
- The viscosity of the lubricant at operating temperature.
- The maximum and minimum allowable operating temperatures.
- The speed at which the bearing will operate.
Grease considerations
The primary advantage of grease over oil is that bearings can be pre-lubricated, eliminating the need for - and the cost of - an external lubrication system. Besides simplicity, grease lubrication also requires less maintenance and has less stringent sealing requirements than oil systems. Grease tends to remain in proximity to bearing components.
The drawbacks of using grease are that it does not conduct heat away from a bearing as efficiently as oil. Also, grease can increase the initial torque within a bearing and cause running torque to be slightly higher. The speed limits for greases (expressed as an ndm value, with ndm being the rpm multiplied by the bearing PCD in mm) are generally lower than for oils due to the plastic nature of grease that tends to cause overheating at high speeds.
In certain applications the design of the bearing and the selection of a suitable grease become very challenging. Here, it is critical that the bearing supplier has the knowledge and experience to suggest a grease that ensures maximum reliability of the bearings over long operating periods without re-lubrication. Current "greased-for-life" bearing technology can consistently give 30,000+ hours of life at 700,000 ndm.
Oil considerations
While grease lubrication is inherently simpler than lubrication with oil, there are still applications where oil is the better choice. In high-speed spindle and turbine applications, for example, oil is supplied continuously and provides cooling as well as lubrication. A further example is instrument bearings with extremely low values of starting and running torque. These require only a minimal, one-time lubrication, each bearing receiving just a few milligrammes of oil.
The limiting speeds for oil-lubricated bearings are governed by the size of the bearing and the design of the cage, rather than by the lubricant itself. To illustrate this, petroleum or diester-based oils can accommodate bearing speeds of up to 1,500,000 ndm or higher. In the case of silicone-based oils, the maximum speed rating drops to 350,000 ndm. Similarly, when calculating life for bearings lubricated with silicone-based oils, the Basic Load Rating (C) should be reduced by two-thirds (C/3). To ensure long life at high speeds, the lubrication system should provide for retention, circulation, filtration and possibly cooling of the oil.
In extremely harsh operating environments such as dry pump bearings, often oil selection is pre-defined to a certain extent by the end user. In dry pumps, the challenge for the bearing supplier is to optimise the design of the bearings in order to make the best use of relatively poor lubrication.
Solid soft film lubricants
Solid soft films are primarily used to provide solid lubrication for bearings in extreme applications where traditional fluid lubricants would be rendered ineffective. They offer the advantages that their friction is independent of temperature, and they do not evaporate or creep in terrestrial vacuum or space environments.
The solid soft film lubricant can either be applied directly to the surface or transferred by rubbing contact from a sacrificial source such as a self-lubricating bearing cage.
Wednesday, 4 January 2017
Bearing clearance
Selecting a clearance class
The clearance values listed in the relevant product chapters are valid for unmounted bearings. To select the best clearance value for an application, the required operating clearance in the bearing (in operation) must be determined first.
Because there are many factors that can influence operating clearance in a bearing, these calculations are best done with the aid of sophisticated computer programs. As a result, recommends using one of the computer programs available through the application engineering service. These programs consider tolerances, fits and component temperatures, to calculate the required initial internal clearance.
The required initial internal clearance of an unmounted bearing can be estimated using
r = rop + Δrfit + Δrtemp
where
r = required internal clearance for the unmounted bearing [mm]
rop = desired operating clearance [mm]
Δrfit = clearance reduction caused by the fit [mm]
Δrtemp = clearance reduction caused by temperature difference [mm]
Clearance reduction caused by an interference fit
The reduction equals the effective interference fit multiplied by a reduction factor using
Δrfit = Δ1 f1 + Δ2 f2
where
Δrfit = clearance reduction caused by the fit [mm]
f1 = reduction factor for the inner ring
f2 = reduction factor for the outer ring
Δ1 = effective interference between the inner ring and shaft [mm]
Δ2 = effective interference between the outer ring and housing [mm]
The reduction factors can be obtained from diagram 1 as a function of the ratio of the bearing bore diameter d to the outside diameter D. It is valid for a solid steel shaft and a cast iron or steel housing. For the effective interference fit, the mean value of the smallest and largest values of the probable .
Clearance reduction caused by a temperature difference between the bearing rings
When the inner ring temperature is higher than the outer ring temperature, the internal clearance within the bearing is reduced. The internal clearance reduction can be estimated using
Δrtemp = α dm ΔT
where
Δrtemp = clearance reduction caused by temperature difference [mm]
dm = bearing mean diameter [mm]
= 0,5 (d + D)
α = thermal coefficient of expansion [°C–1]
= 12 x 10–6 for steel
ΔT = temperature difference between the shaft and housing [°C]
The temperature difference between components during start-up can be much higher than under steady state conditions (diagram 2) and unwanted preload may result. It is important to avoid unwanted preload during startup, because even short periods of preload can have a negative impact on bearing service life. One way to avoid excessive heat and the resulting preload is to start the application at a slow speed and increase the speed incrementally.
Selecting a clearance class
The clearance values listed in the relevant product chapters are valid for unmounted bearings. To select the best clearance value for an application, the required operating clearance in the bearing (in operation) must be determined first.
Because there are many factors that can influence operating clearance in a bearing, these calculations are best done with the aid of sophisticated computer programs. As a result, recommends using one of the computer programs available through the application engineering service. These programs consider tolerances, fits and component temperatures, to calculate the required initial internal clearance.
The required initial internal clearance of an unmounted bearing can be estimated using
r = rop + Δrfit + Δrtemp
where
r = required internal clearance for the unmounted bearing [mm]
rop = desired operating clearance [mm]
Δrfit = clearance reduction caused by the fit [mm]
Δrtemp = clearance reduction caused by temperature difference [mm]
Clearance reduction caused by an interference fit
The reduction equals the effective interference fit multiplied by a reduction factor using
Δrfit = Δ1 f1 + Δ2 f2
where
Δrfit = clearance reduction caused by the fit [mm]
f1 = reduction factor for the inner ring
f2 = reduction factor for the outer ring
Δ1 = effective interference between the inner ring and shaft [mm]
Δ2 = effective interference between the outer ring and housing [mm]
The reduction factors can be obtained from diagram 1 as a function of the ratio of the bearing bore diameter d to the outside diameter D. It is valid for a solid steel shaft and a cast iron or steel housing. For the effective interference fit, the mean value of the smallest and largest values of the probable .
Clearance reduction caused by a temperature difference between the bearing rings
When the inner ring temperature is higher than the outer ring temperature, the internal clearance within the bearing is reduced. The internal clearance reduction can be estimated using
Δrtemp = α dm ΔT
where
Δrtemp = clearance reduction caused by temperature difference [mm]
dm = bearing mean diameter [mm]
= 0,5 (d + D)
α = thermal coefficient of expansion [°C–1]
= 12 x 10–6 for steel
ΔT = temperature difference between the shaft and housing [°C]
The temperature difference between components during start-up can be much higher than under steady state conditions (diagram 2) and unwanted preload may result. It is important to avoid unwanted preload during startup, because even short periods of preload can have a negative impact on bearing service life. One way to avoid excessive heat and the resulting preload is to start the application at a slow speed and increase the speed incrementally.
Tapered Bearing Adjustment
In order to ensure correct adjustment, the tapered bearings are required to have "zero end play" at all times. The procedure to accomplish this in a caster is as follows:Check that each spacer is positioned in the correct place, through the seal and up against the face of each bearing.
Install the wheel into the rig.
Install the axel through the legs, spacers and bearings.
Assemble the slotted nut on the end of the axle and tighten with a wrench until the wheel has sufficient drag to stop the wheel from rotating at all when released from your hand while trying to spin the wheel. This will seat the tapered bearing cones into the cups.
Back the nut off approximately a quarter of a turn to locate the cross drilled hole in the axle and one of the slots in the nut.*
Spin the wheel. When released from your hand, the wheel should turn approximately one half of a rotation.
Install the roll pin.*
The bearings should be checked for the correct adjustment and to assure they are properly lubricated every 500 hours of service or as frequently as possible afterwards.
*Some casters maybe assembled with a Flexloc nut, this product has a locking feature that allows infinite adjustment without using a roll pin to secure the nut.
Tapered Roller Bearing Installation
Install the cup(3) into the wheel bore. The cup (3) must be fully seated against the step in the bore. Make sure the taper of the cup (3) is in the proper orientation.Install the cone (2) into the cup (3). This is a loose fit.
Install the flinger washer (7) on top of the cone (2).
Install the closure (5) over the flinger washer (7). Make sure to fully seat the closure (5) around flinger washer (7) and cup (3).
Repeat above procedure for the opposite side.
Install the wheel (10) into the caster.
Place a spacer (6) between the closure (5) and the caster leg on each side.
Slide the axle (9) through the caster legs and wheel assembly (10).
Install a castle nut (8) and tighten until the wheel (10) will not spin. this will seat the bearings into the bore.
Loosen the castle nut (8) until the wheel (10) is free spinning.
Tighten the castle nut (8) until the wheel (10) begins to drag.
Align the slots in the castle nut (8) with the cross holes in the axle (9) by tightening or loosening the castle nut (8). If tightening, the wheel (10) must be able to spin somewhat freely. If loosening, the wheel (10) cannot have any end play. The bearing should have some pre-load. Install cotter pin or roll pin (4) through the slotted nut (8) and axle (9).
Lubricate bearings through the grease zerk (1) using Shell Alvania Grease 2 or equivalent.
Subscribe to:
Posts (Atom)
