Improved Raceways and Pressed Steel Cages Dramatically Enhance Performance & Versatility
DANBURY, CT, January 23, 2006 - Employing a significantly improved
honing procedure known as "Plateau Finishing," INA/FAG engineers have
dramatically reduced both friction moment and raceway surface roughness
on their new X-Life(TM) Angular Contact Ball Bearings. Together with a
new optimized design of the pressed steel cages, INA/FAG has been able
to increase bearing service life by up to 50%.
Used wherever high thrust loads, high speeds and elevated temperatures
are part of operating conditions - as well as the need for high running
accuracy, the new X-Life Single Row Angular Contact Ball Bearings
utilize these latest advancements to increase the fatigue limiting load
by more than 30%. Numerous applications will benefit from these enhanced
bearings, including electrical machines, pumps, compressors, and air
handling equipment, as well as textile and printing machinery, turbines
and a multitude of gearboxes. Operational advantages include:
o Lower operating costs resulting from reduced friction, lower bearing temperatures and reduced lubricant stressing
o Quieter running
o Suitable for high speeds
o High rigidity
o Universal designs for mounting in pairs
o More efficient bearing arrangements for significantly longer life
o Sealed and lubricated for life
In early 2004, INA/FAG announced its commitment to a new line of
anti-friction bearings called X-Life, which combine the experience,
innovation and problem-solving capabilities of both companies. The
X-Life program brought a new level of standards to rolling bearings and a
significantly improved price/performance ratio, incorporating
advancements in ball and raceway finishes, improved kinematics, special
materials and other innovative processes. The results have meant lower
noise, reduced maintenance, higher load capacity and longer service
life.
The grinding and honing methods used in INA/FAG's new Plateau Finishing
production technology have significantly improved the quality of the
bearing surface finishes and produced a greater profile accuracy of the
raceways. Friction moment has been reduced by up to 10%, and the
fatigue-limiting load has been increased by 30%, resulting in a dramatic
improvement in service life of up to 50%.
Advanced Cage Design
The INA/FAG engineering team carefully evaluated the cage geometry in
the angular contact ball bearings, and completely redesigned the contact
area between the balls and the cage pockets. This helps achieve optimum
contact and avoids wear in the cage pockets resulting from the backward
and forward drifting of the balls. The newly optimized contact geometry
leads to reduced friction and lower energy consumption and also results
in less grease stressing and a reduction in grease contamination. In
fact, tests show that grease life can be extended by up to 200%.
The X-Life Angular Contact Ball Bearings are available with the new
pressed steel cage, and can also be sealed on one or both sides. The
unsealed versions are heat resistant up to 150°C. Compared to bearings
with brass cages, they are appreciably lighter, while offering the same
excellent dynamic running properties. And since these new X-Life
bearings are insensitive to synthetic lubricants and aggressive media,
they are ideally suited for raising the productivity uptime in the
chemical and mineral oil industries. They are also available in
universal design and tolerance class P5 (Abec 5).
Existing brass and polyamide caged versions are still available with the
improved X-Life raceway surface finishes for applications where they
may be better suited than the steel cage variant.
From: http://news.thomasnet.com/fullstory/Ball-Bearings-are-designed-for-optimal-service-life-474507
Showing posts with label ball bearings. Show all posts
Showing posts with label ball bearings. Show all posts
Wednesday, November 14, 2012
Deep Groove Ball Bearings reduce noise in electric motors.
By optimising the contact geometry between the
rolling elements and the ring raceways, Schaeffler's new 'Generation C'
deep groove ball bearings are ideal for electric motors, providing 35%
less friction and 50% less noise.
For designers of electric motors and for plant operators who use these motors, efficiency, noise and vibration levels of the motor are key design and quality criteria. The efficiency of small electric motors with low capacity - the type often found in electrical consumer goods such as washing machines, power tools and ventilators - is mostly determined by the power loss of the internal bearings.
The Schaeffler Group has therefore developed the 'Generation C' range of deep groove ball bearings, which not only offer 35 per cent less friction than its predecessor, but also cut noise levels by 50 per cent. This means a more efficient motor, resulting in reduced energy consumption. The new design improvements mean that the bearings can achieve higher running speeds (rpm), whilst simultaneously increasing the life of the bearing.
The bearings are therefore ideal for applications in which low noise and smooth running are critical. Reduced friction levels and improved energy efficiency from the bearings means a reduction in running costs for plant operators and a more efficient machine with extended maintenance intervals.
In order to reduce friction by 35 per cent, Schaeffler optimised the osculation (raceway curvature) between the balls and rings on the new bearings. This means there is less chance of misalignment between the inner and outer ring. As well as offering less friction, the bearings also generate less heat, making them suitable for higher running speeds.
Schaeffler also modified the seal on the bearings. The new novel HRS seal has modified double lip geometry and is made from nitrile butadiene rubber. These have been adjusted to match the recess on the bearing inner ring. Axial contact between the inner ring and the seal means more effective protection against contamination or loss of grease and less frictional torque. This results in longer grease life, increasing the life and reliability of the bearing and provides improved bearing performance at higher speeds (rpm).
Venting grooves have also been added in order to improve the run-in behaviour of the bearings. In addition to the HRS seal, the bearing shield has been modified. The recesses on the bearing rings and the shield geometry are functionally adjusted to each other in such a way that the sealing efficiency is improved and grease life increased. The new design creates an axial and radial labyrinth with the shield.
The improved guidance of the rolling elements also contributes to higher performance of the bearing. The new riveted steel cage, which replaces the previous steel 'ribbon' cage, offers higher rigidity and so is suitable for higher running speeds. The riveted steel cage also reduces noise levels and means the bearing is less sensitive to shock loads. The manufacturing tolerance of the bearings has also been increased (to P5 Abec 5 standards), ball roundness to G5 tolerances and improved surface finish.
The dimensions of the new bearings correspond to the previous bearing types, enabling easy replacement. Generation C bearings can operate in temperatures from -30°C up to +120°C.
The bearings are available with outside diameters from 26mm up to 90mm. Riveted steel cages are standard, although polyamide cages are optional. P6 or P5 tolerances can be specified on ordering. Sealing options include one or two gap seals; one or two lip seals; or low friction, non-contact labyrinth seals.
From: http://news.thomasnet.com/fullstory/Deep-Groove-Ball-Bearings-reduce-noise-in-electric-motors-561078
For designers of electric motors and for plant operators who use these motors, efficiency, noise and vibration levels of the motor are key design and quality criteria. The efficiency of small electric motors with low capacity - the type often found in electrical consumer goods such as washing machines, power tools and ventilators - is mostly determined by the power loss of the internal bearings.
The Schaeffler Group has therefore developed the 'Generation C' range of deep groove ball bearings, which not only offer 35 per cent less friction than its predecessor, but also cut noise levels by 50 per cent. This means a more efficient motor, resulting in reduced energy consumption. The new design improvements mean that the bearings can achieve higher running speeds (rpm), whilst simultaneously increasing the life of the bearing.
The bearings are therefore ideal for applications in which low noise and smooth running are critical. Reduced friction levels and improved energy efficiency from the bearings means a reduction in running costs for plant operators and a more efficient machine with extended maintenance intervals.
In order to reduce friction by 35 per cent, Schaeffler optimised the osculation (raceway curvature) between the balls and rings on the new bearings. This means there is less chance of misalignment between the inner and outer ring. As well as offering less friction, the bearings also generate less heat, making them suitable for higher running speeds.
Schaeffler also modified the seal on the bearings. The new novel HRS seal has modified double lip geometry and is made from nitrile butadiene rubber. These have been adjusted to match the recess on the bearing inner ring. Axial contact between the inner ring and the seal means more effective protection against contamination or loss of grease and less frictional torque. This results in longer grease life, increasing the life and reliability of the bearing and provides improved bearing performance at higher speeds (rpm).
Venting grooves have also been added in order to improve the run-in behaviour of the bearings. In addition to the HRS seal, the bearing shield has been modified. The recesses on the bearing rings and the shield geometry are functionally adjusted to each other in such a way that the sealing efficiency is improved and grease life increased. The new design creates an axial and radial labyrinth with the shield.
The improved guidance of the rolling elements also contributes to higher performance of the bearing. The new riveted steel cage, which replaces the previous steel 'ribbon' cage, offers higher rigidity and so is suitable for higher running speeds. The riveted steel cage also reduces noise levels and means the bearing is less sensitive to shock loads. The manufacturing tolerance of the bearings has also been increased (to P5 Abec 5 standards), ball roundness to G5 tolerances and improved surface finish.
The dimensions of the new bearings correspond to the previous bearing types, enabling easy replacement. Generation C bearings can operate in temperatures from -30°C up to +120°C.
The bearings are available with outside diameters from 26mm up to 90mm. Riveted steel cages are standard, although polyamide cages are optional. P6 or P5 tolerances can be specified on ordering. Sealing options include one or two gap seals; one or two lip seals; or low friction, non-contact labyrinth seals.
From: http://news.thomasnet.com/fullstory/Deep-Groove-Ball-Bearings-reduce-noise-in-electric-motors-561078
Friday, November 9, 2012
Stainless steel deep groove ball bearings and its tolerances
There are several common designs of ball bearing, each offering various
trade-offs. They can be made from many different materials, including: stainless steel, chrome steel, and ceramic (silicon nitride (Si3N4)). A hybrid ball bearing is a bearing with ceramic balls and races of metal.
SKF stainless steel deep groove ball bearings are resistant
to corrosion from moisture and several other media. These
single row deep groove ball bearings have the same deep
raceway grooves and close conformity between raceways and
balls as standard deep groove ball bearings made of carbon
chromium (rolling bearing) steel. They are without filling
slots and can carry axial loads acting in both directions in
addition to radial loads, even at high speeds.
SKF stainless steel deep groove ball bearings have the same
running properties as conventional steel deep groove ball
bearings, but have a lower load carrying capacity.
The bearings are available in open and sealed designs for
shaft diameters from 1 to 50 mm.
SKF stainless steel bearings are identified by the
designation prefix W, e.g. W 626-2Z.
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Tuesday, October 30, 2012
How are ball bearings made?
Background
Ever since man began to need to move things, he has used round rollers to make the job easier. Probably the first rollers were sticks or logs, which were a big improvement over dragging things across the ground, but still pretty hard work. Egyptians used logs to roll their huge blocks of stone for the pyramids. Eventually, someone came up with the idea of securing the roller to whatever was being moved, and built the first "vehicle" with "wheels." However, these still had bearings made from materials rubbing on each other instead of rolling on each other. It wasn't until the late eighteenth century that the basic design for bearings was developed. In 1794, Welsh ironmaster Philip Vaughan patented a design for ball bearings to support the axle of a carriage. Development continued in the nineteenth and early twentieth centuries, spurred by the advancement of the bicycle and the automobile.
There are thousands of sizes, shapes, and kinds of rolling bearings; ball bearings, roller bearings, needle bearings, and tapered roller bearings are the major kinds. Sizes run from small enough to run miniature motors to huge bearings used to support rotating parts in hydroelectric power plants; these large bearings can be ten feet (3.04 meters) in diameter and require a crane to install. The most common sizes can easily be held in one hand and are used in things like electric motors.
This article will describe only ball bearings. In these bearings, the rolling part is a ball, which rolls between inner and outer rings called races. The balls are held by a cage, which keeps them evenly spaced around the races. In addition to these parts, there are a lot of optional parts for special bearings, like seals to keep oil or grease in and dirt out, or screws to hold a bearing in place. We won't worry here about these fancy extras.
Raw Materials
Almost all parts of all ball bearings are made of steel. Since the bearing has to stand up to a lot of stress, it needs to be made of very strong steel. The standard industry classification for the steel in these bearings is 52100, which means that it has one percent chromium and one percent carbon (called alloys when added to the basic steel). This steel can be made very hard and tough by heat treating. Where rusting might be a problem, bearings are made from 440C stainless steel.
The cage for the balls is traditionally made of thin steel, but some bearings now use molded plastic cages, because they cost less to make and cause less friction.
The Manufacturing Process
There are four major parts to a standard ball bearing: the outer race, the rolling balls, the inner race, and the cage.
Races
• 1 Both races are made in almost the same way. Since they are both rings of steel, the process starts with steel tubing of an appropriate size. Automatic machines similar to lathes use cutting tools to cut the basic shape of the race, leaving all of the dimensions slightly too large. The reason for leaving them too large is that the races must be heat treated before being finished, and the steel
Surprisingly, the rolling balls start out as thick steel wire. Then, in a cold heading process, the wire is cut into small pieces smashed between two steel dies. The result is a ball that looks like the planet Saturn, with a ring around its middle called "flash." usually warps during this process. They can be machined back to their finished size after heat treating.
• 2 The rough cut races are put into a heat treating furnace at about 1,550 degrees Fahrenheit (843 degrees Celsius) for up to several hours (depending on the size of the parts), then dipped into an oil bath to cool them and make them very hard. This hardening also makes them brittle, so the next step is to temper them. This is done by heating them in a second oven to about 300 degrees Fahrenheit (148.8 degrees Celsius), and then letting them cool in air. This whole heat treatment process makes parts which are both hard and tough.
• 3 After the heat treatment process, the races are ready for finishing. However, the races are now too hard to cut with cutting tools, so the rest of the work must be done with grinding wheels. These are a lot like what you would find in any shop for sharpening drill bits and tools, except that several different kinds and shapes are needed to finish the races. Almost every place on the race is finished by grinding, which leaves a very smooth, accurate surface. The surfaces where the bearing fits into the machine must be very round, and the sides must be flat. The surface that the balls roll on is ground first, and then lapped. This means that a very fine abrasive slurry is used to polish the races for several hours to get almost a mirror finish. At this point, the races are finished, and ready to be put together with the balls.
Balls
• 4 The balls are a little more difficult to make, even though their shape is very simple. Surprisingly, the balls start out as thick wire. This wire is fed from a roll into a machine that cuts off a short piece, and then smashes both ends in toward the middle. This process is called cold heading. Its name comes from the fact that the wire is not
The bulge around the middle of the rolling balls is removed in a machining proess. The balls are placed in rough grooves between two cast iron discs. One disc rotates while the other one is stationary; the friction removes the flash. From here, the balls are heat treated, ground, and lapped, which leaves the balls with a very smooth finish.
heated before being smashed, and that the original use for the process was to put the heads on nails (which is still how that is done). At any rate, the balls now look like the planet Saturn, with a ring around the middle called "flash."
• 5 The first machining process removes this flash. The ball bearings are put between the faces of two cast iron disks, where they ride in grooves. The inside of the grooves are rough, which tears the flash off of the balls. One wheel rotates, while the other one stays still. The stationary wheel has holes through it so that the balls can be fed into and taken out of the grooves. A special conveyor feeds balls into one hole, the balls rattle around the groove, and then come out the other hole. They are then fed back into the conveyor for many trips through the wheel grooves, until they have been cut down to being fairly round, almost to the proper size, and the flash is completely gone. Once again, the balls are left oversize so that they can be ground to their finished size after heat treatment. The amount of steel left for finishing is not much; only about 8/1000 of an inch (.02 centimeter), which is about as thick as two sheets of paper.
• 6 The heat treatment process for the balls is similar to that used for the races, since the kind of steel is the same, and it is best to have all the parts wear at about the same rate. Like the races, the balls become hard and tough after heat treating and tempering. After heat treatment, the balls are put back into a machine that works the same way as the flash remover, except that the wheels are grinding wheels instead of cutting wheels. These wheels grind the balls down so that they are round and within a few ten thousandths of an inch of their finished size.
• 7 After this, the balls are moved to a lapping machine, which has cast iron wheels and uses the same abrasive lapping compound as is used on the races. Here, they will be lapped for 8-10 hours, depending on
The four parts of a finished ball bearing: inner race, outer race, cage, and ball. how precise a bearing they are being made for. Once again, the result is steel that is extremely smooth.
Cage
• 8 Steel cages are stamped out of fairly thin sheet metal, much like a cookie cutter, and then bent to their final shape in a die. A die is made up of two pieces of steel that fit together, with a hole the shape of the finished part carved inside. When the cage is put in between and the die is closed, the cage is bent to the shape of the hole inside. The die is then opened, and the finished part is taken out, ready to be assembled.
• 9 Plastic cages are usually made by a process called injection molding. In this process, a hollow metal mold is filled by squirting melted plastic into it, and letting it harden. The mold is opened up, and the finished cage is taken out, ready for assembly.
Assembly
• 10 Now that all of the parts are made, the bearing needs to be put together. First, the inner race is put inside the outer race, only off to one side as far as possible. This makes a space between them on the opposite side large enough to insert balls between them. The required number of balls is put in, then the races are moved so that they are both centered, and the balls distributed evenly around the bearing. At this point, the cage is installed to hold the balls apart from each other. Plastic cages are usually just snapped in, while steel cages usually have to be put in and riveted together. Now that the bearing is assembled, it is coated with a rust preventative and packaged for shipping.
Quality Control
Bearing making is a very precise business. Tests are run on samples of the steel coming to the factory to make sure that it has the right amounts of the alloy metals in it. Hardness and toughness tests are also done at several stages of the heat treating process. There are also many inspections along the way to make sure that sizes and shapes are correct. The surface of the balls and where they roll on the races must be exceptionally smooth. The balls can't be out of round more than 25 millionths of an inch, even for an inexpensive bearing. High-speed or precision bearings are allowed only five-millionths of an inch.
The Future
Ball bearings will be used for many years to come, because they are very simple and have become very inexpensive to manufacture. Some companies experimented with making balls in space on the space shuttle. In space, molten blobs of steel can be spit out into the air, and the zero gravity lets them float in the air. The blobs automatically make perfect spheres while they cool and harden. However, space travel is still expensive, so a lot of polishing can be done on the ground for the cost of one "space ball".
Other kinds of bearings are on the horizon, though. Bearings where the two objects never touch each other at all are efficient to run but difficult to make. One kind uses magnets that push away from each other and can be used to hold things apart. This is how the "mag-lev" (for magnetic levitation) trains are built. Another kind forces air into a space between two close-fitting surfaces, making them float apart from each other on a cushion of compressed air. However, both of these bearings are much more expensive to build and operate than the humble, trusted ball bearing.
Resource: http://www.madehow.com/Volume-1/Ball-Bearing.html#b#ixzz2Ar8VaLSH
Ever since man began to need to move things, he has used round rollers to make the job easier. Probably the first rollers were sticks or logs, which were a big improvement over dragging things across the ground, but still pretty hard work. Egyptians used logs to roll their huge blocks of stone for the pyramids. Eventually, someone came up with the idea of securing the roller to whatever was being moved, and built the first "vehicle" with "wheels." However, these still had bearings made from materials rubbing on each other instead of rolling on each other. It wasn't until the late eighteenth century that the basic design for bearings was developed. In 1794, Welsh ironmaster Philip Vaughan patented a design for ball bearings to support the axle of a carriage. Development continued in the nineteenth and early twentieth centuries, spurred by the advancement of the bicycle and the automobile.
There are thousands of sizes, shapes, and kinds of rolling bearings; ball bearings, roller bearings, needle bearings, and tapered roller bearings are the major kinds. Sizes run from small enough to run miniature motors to huge bearings used to support rotating parts in hydroelectric power plants; these large bearings can be ten feet (3.04 meters) in diameter and require a crane to install. The most common sizes can easily be held in one hand and are used in things like electric motors.
This article will describe only ball bearings. In these bearings, the rolling part is a ball, which rolls between inner and outer rings called races. The balls are held by a cage, which keeps them evenly spaced around the races. In addition to these parts, there are a lot of optional parts for special bearings, like seals to keep oil or grease in and dirt out, or screws to hold a bearing in place. We won't worry here about these fancy extras.
Raw Materials
Almost all parts of all ball bearings are made of steel. Since the bearing has to stand up to a lot of stress, it needs to be made of very strong steel. The standard industry classification for the steel in these bearings is 52100, which means that it has one percent chromium and one percent carbon (called alloys when added to the basic steel). This steel can be made very hard and tough by heat treating. Where rusting might be a problem, bearings are made from 440C stainless steel.
The cage for the balls is traditionally made of thin steel, but some bearings now use molded plastic cages, because they cost less to make and cause less friction.
The Manufacturing Process
There are four major parts to a standard ball bearing: the outer race, the rolling balls, the inner race, and the cage.
Races
• 1 Both races are made in almost the same way. Since they are both rings of steel, the process starts with steel tubing of an appropriate size. Automatic machines similar to lathes use cutting tools to cut the basic shape of the race, leaving all of the dimensions slightly too large. The reason for leaving them too large is that the races must be heat treated before being finished, and the steel
Surprisingly, the rolling balls start out as thick steel wire. Then, in a cold heading process, the wire is cut into small pieces smashed between two steel dies. The result is a ball that looks like the planet Saturn, with a ring around its middle called "flash." usually warps during this process. They can be machined back to their finished size after heat treating.
• 2 The rough cut races are put into a heat treating furnace at about 1,550 degrees Fahrenheit (843 degrees Celsius) for up to several hours (depending on the size of the parts), then dipped into an oil bath to cool them and make them very hard. This hardening also makes them brittle, so the next step is to temper them. This is done by heating them in a second oven to about 300 degrees Fahrenheit (148.8 degrees Celsius), and then letting them cool in air. This whole heat treatment process makes parts which are both hard and tough.
• 3 After the heat treatment process, the races are ready for finishing. However, the races are now too hard to cut with cutting tools, so the rest of the work must be done with grinding wheels. These are a lot like what you would find in any shop for sharpening drill bits and tools, except that several different kinds and shapes are needed to finish the races. Almost every place on the race is finished by grinding, which leaves a very smooth, accurate surface. The surfaces where the bearing fits into the machine must be very round, and the sides must be flat. The surface that the balls roll on is ground first, and then lapped. This means that a very fine abrasive slurry is used to polish the races for several hours to get almost a mirror finish. At this point, the races are finished, and ready to be put together with the balls.
Balls
• 4 The balls are a little more difficult to make, even though their shape is very simple. Surprisingly, the balls start out as thick wire. This wire is fed from a roll into a machine that cuts off a short piece, and then smashes both ends in toward the middle. This process is called cold heading. Its name comes from the fact that the wire is not
The bulge around the middle of the rolling balls is removed in a machining proess. The balls are placed in rough grooves between two cast iron discs. One disc rotates while the other one is stationary; the friction removes the flash. From here, the balls are heat treated, ground, and lapped, which leaves the balls with a very smooth finish.
heated before being smashed, and that the original use for the process was to put the heads on nails (which is still how that is done). At any rate, the balls now look like the planet Saturn, with a ring around the middle called "flash."
• 5 The first machining process removes this flash. The ball bearings are put between the faces of two cast iron disks, where they ride in grooves. The inside of the grooves are rough, which tears the flash off of the balls. One wheel rotates, while the other one stays still. The stationary wheel has holes through it so that the balls can be fed into and taken out of the grooves. A special conveyor feeds balls into one hole, the balls rattle around the groove, and then come out the other hole. They are then fed back into the conveyor for many trips through the wheel grooves, until they have been cut down to being fairly round, almost to the proper size, and the flash is completely gone. Once again, the balls are left oversize so that they can be ground to their finished size after heat treatment. The amount of steel left for finishing is not much; only about 8/1000 of an inch (.02 centimeter), which is about as thick as two sheets of paper.
• 6 The heat treatment process for the balls is similar to that used for the races, since the kind of steel is the same, and it is best to have all the parts wear at about the same rate. Like the races, the balls become hard and tough after heat treating and tempering. After heat treatment, the balls are put back into a machine that works the same way as the flash remover, except that the wheels are grinding wheels instead of cutting wheels. These wheels grind the balls down so that they are round and within a few ten thousandths of an inch of their finished size.
• 7 After this, the balls are moved to a lapping machine, which has cast iron wheels and uses the same abrasive lapping compound as is used on the races. Here, they will be lapped for 8-10 hours, depending on
The four parts of a finished ball bearing: inner race, outer race, cage, and ball. how precise a bearing they are being made for. Once again, the result is steel that is extremely smooth.
Cage
• 8 Steel cages are stamped out of fairly thin sheet metal, much like a cookie cutter, and then bent to their final shape in a die. A die is made up of two pieces of steel that fit together, with a hole the shape of the finished part carved inside. When the cage is put in between and the die is closed, the cage is bent to the shape of the hole inside. The die is then opened, and the finished part is taken out, ready to be assembled.
• 9 Plastic cages are usually made by a process called injection molding. In this process, a hollow metal mold is filled by squirting melted plastic into it, and letting it harden. The mold is opened up, and the finished cage is taken out, ready for assembly.
Assembly
• 10 Now that all of the parts are made, the bearing needs to be put together. First, the inner race is put inside the outer race, only off to one side as far as possible. This makes a space between them on the opposite side large enough to insert balls between them. The required number of balls is put in, then the races are moved so that they are both centered, and the balls distributed evenly around the bearing. At this point, the cage is installed to hold the balls apart from each other. Plastic cages are usually just snapped in, while steel cages usually have to be put in and riveted together. Now that the bearing is assembled, it is coated with a rust preventative and packaged for shipping.
Quality Control
Bearing making is a very precise business. Tests are run on samples of the steel coming to the factory to make sure that it has the right amounts of the alloy metals in it. Hardness and toughness tests are also done at several stages of the heat treating process. There are also many inspections along the way to make sure that sizes and shapes are correct. The surface of the balls and where they roll on the races must be exceptionally smooth. The balls can't be out of round more than 25 millionths of an inch, even for an inexpensive bearing. High-speed or precision bearings are allowed only five-millionths of an inch.
The Future
Ball bearings will be used for many years to come, because they are very simple and have become very inexpensive to manufacture. Some companies experimented with making balls in space on the space shuttle. In space, molten blobs of steel can be spit out into the air, and the zero gravity lets them float in the air. The blobs automatically make perfect spheres while they cool and harden. However, space travel is still expensive, so a lot of polishing can be done on the ground for the cost of one "space ball".
Other kinds of bearings are on the horizon, though. Bearings where the two objects never touch each other at all are efficient to run but difficult to make. One kind uses magnets that push away from each other and can be used to hold things apart. This is how the "mag-lev" (for magnetic levitation) trains are built. Another kind forces air into a space between two close-fitting surfaces, making them float apart from each other on a cushion of compressed air. However, both of these bearings are much more expensive to build and operate than the humble, trusted ball bearing.
Resource: http://www.madehow.com/Volume-1/Ball-Bearing.html#b#ixzz2Ar8VaLSH
Thursday, October 25, 2012
Compressive strength influences on the performance of IKO deep groove ball bearings
Compressive strength refers to the ability that do not crush or size does not change when bearing accomodate load.
How to ensure deep groove ball bearings used normal in the course, how to make IKO bearings be without injury and with longer life.Let me introduce some notes making bearing work well, which I wish to help you. Under normal circumstances, there are points as follows:
1, appropriate clearance of deep groove ball bearing, too large will impact, too small is poor lubrication that may be burnt.
2, improve quality of lubrication and control oil pressure, temperature and flow, strengthen the oil filter.
3, deep groove ball bearings and axle geometry and surface quality should be strictly guaranteed.
4, adopted in accordance with the demarcation of the fuel and lubricating oil.
5, control of engine temperature, in the under cooling or overheating cases is negative. In cold weather, preheating before starting of diesel engines and scroll hand crank that oil into the friction surface.
Cleanliness of bearing considerable influence on bearing life considerably. IKO bearings have special tests, with the result that their differences for a few times and even dozens of times to more than double. Higher cleanliness of bearing,the longer life.Therefore, improving the cleanliness of the lubricant can extend bearing life, also, with dirt particles of lubricating oil control under below 10 um, IKO bearings life can increase.
Influences on the lubrication properties
IKO bearings drop in cleanliness, not only affect the lubricant film formation, but also cause deterioration and aging of grease, thus affecting the grease lubrication performance.
Wednesday, October 24, 2012
Single row ball bearings
Single row ball bearings have raceways in the inner and outer rings that are displaced with respect to each other in the direction of the bearing axis. This means that they are designed to accommodate combined loads, i.e. simultaneously acting radial and axial loads.
The axial load carrying capacity of Single row ball bearings increases with increasing contact angle. The contact angle a is defined as the angle between the line joining the points of contact of the ball and the raceways in the radial plane, along which the load is transmitted from one raceway to another, and a line perpendicular to the bearing axis
It include the following types:
- single row angular contact ball bearings
- double row angular contact ball bearings
-four-point contact ball bearings
It include the following types:
- single row angular contact ball bearings
- double row angular contact ball bearings
-four-point contact ball bearings
High speed angular contact ball bearings
Check more infomation http://www.hiana-bearings.com/single_row_ball_bearings.htm and for products at http://www.hisupplier.com/a-single-row-ball-bearing/
Tuesday, October 23, 2012
SKF single row angular contact ball bearings
SKF paired single row angular contact ball bearing have 72XX and 73XX two series and bearing accuracy is P6 level. They can form any group dubbed the back-to-back or face-to-face. Their suffix meaning:
B--40 °;
E--high carrying capacity;
CB/GA--clearance/preload
SKF has 3 clearance level:
CB--standard axial clearance, bearings installed;
CC--axial clearance less than CB;
CA--axial clearance less than CC
SKF also has 3 types of preload class:
GA--light preload;
GB--preload than GA class;
GC--preload is larger than GB level;
Cage type:
SKF offers two types of centrifugal pump cage bearings applied to petrochemical industry. Machined brass cage (m) and hammer-type steel cage (j). Using instead plastic cage bearing is strictly prohibited.
Here we elect suffix is BECBM angular contact ball bearings used in petrochemical industry of centrifugal pumps. Not just because it is less after staging the bearing internal clearance (CB) is a good control over rolling bearing with sliding and machined brass cage more sturdy than the blow pressed-steel cage design, with high working reliability. Because of this, many petrochemical companies are using the suffix BECBM bearings as they are standard.
Single and double row angular contact ball bearings
Angular contact ball bearings of 70,000 are composed of the outer ring, inner ring,steel balls and cage. It can bear both radial and axial loads, can also be subjected to purely axial load, stability at higher speeds. Single row angular contact ball bearings can only withstand axial load in one direction. When the bearings under purely radial load, due to the line and rolling load radial load line is not the same in the radial plane, generating internal axial force, it must be installed in pairs.
1. single row angular contact ball bearings are single row angular contact ball bearings have the following structure:
(1) the separation of angular contact ball bearings
The bearing code number is S70000, its ring road does not lock, and the outline of the inner ring, cage, ball separation of components, which can be installed separately. Such as inner diameter of miniature bearing less than 10MM, for gyro rotor, micro-motors for dynamic balance, noise, vibration, stability has a higher requirement of appliance.
(2) non-separation of angular contact ball bearings
Channel lock for this type of bearing rings, rings of the two cannot be separated. By contact angle is divided into three types:
① contact angle α = 40 °, apply to take large axial loads;
② the contact angle α = 25 °, used for precision spindle bearings;
③ the contact angle α = 15 °, more for larger sizes of ball bearings.
(3) configured in pairs of the angular contact ball bearing
Paired angular contact ball bearings that are configured for both radial and axial loads, or you can take pure radial loads and axial loads in either direction. Such bearings by the factory preload requirements, combination matching pairs, available to users. When the bearings are mounted in the machine gets fixed after, completely eliminating the clearance in the bearing and outline of rings and balls in the preloaded State, thereby enhancing bearing steel.
Configured in pairs of angular contact ball bearings are available in three different configurations:
① back-to-back, post code for DB (for example, 70000/DB), this configuration is steel good, shoulder an overturning moment of the performance, can be subjected to bi-directional axial bearing load;
② face to face configuration, post code for DF (such as 70000/DF), rigidity and ability to withstand overturning moment of this configuration than the DB configuration forms, can be subjected to bi-directional axial bearing load;
③ tandem configuration, rear code-named DT (such as 70000/DT), this configuration is also available on the same bearing series of three or more bearings, but can only take a single direction axial loads. Typically, in order to balance and limit the axial displacement of the shaft and the other supporting Office installation to axial load bearing can bear the other party.
In addition, there is a any paired single row angular contact ball bearings. These bearings with a special process, two face-to-face or back-to-back, two-line combination in any way, axial clearance of paired combinations can be selected as needed, post code CA said smaller axial clearance, CB represents moderate axial clearance, CC larger axial clearance.
Universal pair of bearings, can be configured to have an interference by using requirements bearing, and later reset code GA, GB, GC said. GA paired with smaller interference; GB pairing with medium interference; a greater interference of GC said after the match.
2. double row angular contact ball bearings
Characteristics of double row angular contact ball bearing can bear both radial and axial loads combined load, limit the axial displacement of both sides of the axis.
Compared with the double-direction thrust ball bearings, these bearings the speed limit higher, contact angle 32 °, although good, affordable overturning moment, widely used in the front wheels of the car (some models also used the same dimensions of double row tapered roller bearings).
Double row angular contact ball bearings of the structure there are four variants:
(1) A diameter less than or equal to the 90mm bearings of standard design. No filling slots, thus subjected to bi-directional axial loads. With a lightweight glass fibre reinforced polyamide 66 cage, bearing temperature rise is small.
(2) A-type outer diameter is greater than the 90mm bearings of standard design. Filling slots on one side, with pressed window-type steel cages or solid cage of brass.
(3) E-type is a reinforced structure, with filling slots on one side, can fit into a larger number of steel balls, high bearing capacity.
(4) with shields on both sides both sides-and a-type design with sealing ring type and e-type design of double row angular contact ball bearings are available with shields on both sides (non-contact) or seals (contact). Sealed bearings are filled with rust inhibiting lithium base grease, operating temperature -30~+110 degrees centigrade. During use do not need lubrication, installation should not be heated, and should not be cleaned.
Double row angular contact ball bearing installation attention should be paid, although subjected to bi-directional axial bearing load, but when filling slots on one side, you should be careful not to allow the main axial loads through the Groove edge on one side of the gap.
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