Later, in August 1869, Parisian bicycle mechanic Jules Suriray received the first French patent for ball bearings.[4] The bearings were then fitted to the winning bicycle ridden by James Moore in the world's first bicycle road race, Paris-Rouen, in November 1869.[5]

During World War II, German ball bearing factories were often a target of allied aerial bombings; such was the importance of the ball bearing to the German war industry.[9]

The outer race may be split axially or radially, or a hole drilled in it for filling. These approaches allow a full complement to be used, but also limit the orientation of loads or the amount of misalignment the bearing can tolerate. Thus, these designs find much less use.

Modern impact wrenches are very powerful. Many can produce 500 to 1000 ft. lbs. of torque, which is more than most automotive engines. But they do not tighten to a precise amount of torque. A torque wrench is specifically designed to help you torque a fastener to a precise measurement, which is necessary when installing a wheel hub assembly. The amount of torque you use makes a big difference in your wheel hub’s performance. For example, an over-torqued assembly takes on excessive load. An under-torqued assembly can reduce the bearing’s lifespan or even cause the bearing assembly to fail.

Ball bearing

Ceramic hybrid ball bearings use these ceramic balls in place of steel balls. They are constructed with steel inner and outer rings, but ceramic balls; hence the hybrid designation.

A ball bearing, an engineering term, refers to a type of rolling-element bearing that uses balls to maintain the separation between the moving parts of the bearing. 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. Usually one of the races is held fixed. As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling, their coefficient of friction is much lower than that of two flat surfaces rotating against each other.

When you have a failed wheel hub, it’s possible that the bore of the knuckle is damaged, too. That can cause premature wheel bearing failure. When the old hub is removed, use the opportunity to inspect the knuckle for damage. Look for corrosion and make sure a bore gauge rotates in the bore without any trouble. Also, before installing the new hub check it’s runout. As a rule of thumb, on a modern vehicle, hub runout should be between .000″ and .0015″. If you take the time to verify the hub before installation, any other runout issues will be easier to troubleshoot. For example, if the rotor shows runout when it is re-installed, you’ll know that either:

One interesting application for ball bearings has been implemented at the San Francisco International Airport. In the airport there are 267 columns which are used to bear the weight of the airport. Each column is placed on a steel ball bearing with a diameter of five feet. The ball sits in a concave foundation. If an earthquake occurs, the ground can move up to 20 inches in any direction, as the columns roll on their bases. This is an effective way to separate the building from the movement of the ground. After the earthquake has ended, the columns are re-centered on their bases by the force of gravity.[7]

Bearing

Self-aligning ball bearings are constructed with the inner ring and ball assembly contained within an outer ring that has a spherical raceway. This construction allows the bearing to tolerate a small angular misalignment resulting from deflection or improper mounting.

The modern, self-aligning design of the ball bearing is attributed to Sven Wingquist of the SKF ball-bearing manufacturer in 1907.

Magnetic bearings

An angular contact ball bearing uses axially asymmetric races. An axial load passes in a straight line through the bearing, whereas a radial load takes an oblique path that tends to want to separate the races axially. So the angle of contact on the inner race is the same as that on the outer race. Angular contact bearings better support "combined loads" (loading in both the radial and axial directions) and the contact angle of the bearing should be matched to the relative proportions of each. The larger the contact angle (typically in the range of ten to 45 degrees), the higher the axial load supported, but the lower the radial load.

Ball bearings are also used for dental and medical instruments. In dental and medical hand pieces, it is necessary for the pieces to withstand sterilization and corrosion. Because of this requirement, dental and medical hand pieces are made from 440C stainless steel, which allows for smooth rotations at fast speeds.[8]

The bearings used for computer hard drives were used to be highly spherical and said to be the best spherical shapes manufactured. However, such bearings are being increasingly replaced with fluid bearings.

A slot-fill radial bearing is one in which the inner and outer races are notched so that when they are aligned, balls can be slipped in the slot in order to fill the bearing. A slot-fill bearing has the advantage that the entire groove is filled with balls, called a full complement. A slot-fill bearing has the disadvantages that it handles axial loads poorly, and the notches weaken the races. Note that an angular contact bearing can be disassembled axially and so can easily be filled with a full complement.

Rollingbearing

Ceramic bearing balls weigh up to 40 percent less than steel bearing balls, depending on size. This reduces centrifugal loading and skidding, so hybrid ceramic bearings can operate 20 to 40 percent faster than conventional bearings. This means that the outer race groove exerts less force inward against the ball as the bearing spins. This reduction in force reduces the friction and rolling resistance. The lighter ball allows the bearing to spin faster, and uses less energy to maintain its speed.

A wheel hub is a part you absolutely should not skimp on because it plays an important part in ensuring that your wheels function properly. A low-quality wheel hub assembly is likely to bring on a whole lot of problems shortly after installation because it’s not designed to hold up well over time.

A deep-groove radial bearing is one in which the race dimensions are close to the dimensions of the balls that run in it. Deep-groove bearings have higher load ratings for their size than shallow-groove bearings, but they are also less tolerant of misalignment of the inner and outer races. A misaligned shallow-groove bearing may support a larger load than a similar deep-groove bearing with similar misalignment.

A wheel hub assembly is one of those parts that need to be installed the right way the first time. An improperly installed wheel hub assembly causes quite a few problems, such as:

Today, ball bearings are used in numerous applications that are important in everyday life. For example, they are found in the moving parts of bicycles, automobiles, turbines, and jet engines.

There are several common designs of ball bearings, each offering various tradeoffs. They can be made from many different materials, including stainless steel, chrome steel, and ceramic. A hybrid ball bearing is a bearing with ceramic balls and races of metal.

The modern ball bearing design appears to have originated in the late eighteenth century.[2] Philip Vaughan, a Welsh inventor and ironmaster, patented the first design for ball bearings in Carmarthen in 1794.[3] Designed to support a carriage axle, the ball bearings ran along a track (or ball race) in an axle assembly.

An axial ball bearing uses side-by-side races. An axial load is transmitted directly through the bearing, while a radial load is poorly supported, tends to separate the races, and anything other than a small radial load is likely to damage the bearing.

Needle rollerbearing

ballbearing中文

Most ball bearings are single-row designs. Some double-row designs are available but they need better alignment than single-row bearings.

In high-speed applications, such as turbines, jet engines, and dentistry equipment, the centrifugal forces generated by the balls will change the contact angle at the inner and outer races. Ceramics such as silicon nitride are now regularly used in such applications due to its low density (40 percent of steel, and thus significantly lower centrifugal force), its ability to function in high temperature environments, and the fact that it tends to wear in a way similar to bearing steel (rather than cracking or shattering like glass or porcelain).

A Conrad bearing is assembled by placing the inner and outer races radially offset, so the races touch at one point and have a large gap on the radially opposite side. The bearing is then filled by placing balls into the large gap, then distributing them around the bearing assembly. The act of distributing the balls causes the inner and outer races to become concentric. If the balls were left free, the balls could resume their offset locations and the bearing could disassemble itself. For this reason, a cage is inserted to hold the balls in their distributed positions. The cage supports no bearing load; it serves to keep the balls located. Conrad bearings have the advantage that they take both radial and axial loads, but their disadvantage is that they cannot be filled to a full complement and thus have reduced load-carrying capacity compared to a full-complement bearing. The Conrad bearing is named for its inventor, Robert Conrad, who got British patent 12,206 in 1903 and U.S. patent 822,723 in 1906. Probably the most familiar industrial ball bearing is the deep-groove Conrad style. The bearing is used in most of the mechanical industries.

Most bicycles use angular-contact bearings in the headsets because the forces on these bearings are in both the radial and axial directions.

There may be debris in the axle shaft and on the wheel speed sensor that could affect your new hub’s performance. It’s important to ensure that both areas are clean before installing the new hub. It only takes a few minutes. You can use a wire brush, emery cloth, or a fine file. Don’t use any lubricants on the axle shaft threads. Lubricants affect torque readings.

Rolling elementbearing

Ball bearings are currently used in numerous applications that are important in everyday life. Examples include the moving parts of bicycles, automobiles, turbines, jet engines, and dental equipment.

Replacing a wheel hub assembly requires some finesse. Take a look at this list of 5 of the most common mistakes to avoid while replacing wheel hubs:

When it comes to wheel hubs, quality is everything. You want to put the best quality hubs in your customers” cars in order to reduce comebacks. When looking for a high-quality wheel hub assembly to keep in stock, you want to get one that’s:

Sometimes it’s tempting to reuse the old nut. We strongly recommend against it. Self-staking nuts are only intended to be tightened once. A reused nut can loosen on the road.

Caged bearings typically have fewer balls than a full complement, and thus have reduced load capacity. However, cages keep balls from scuffing directly against each other and so can reduce the drag of a loaded bearing. Caged roller bearings were invented by John Harrison in the mid-1700s as part of his work on chronographs.[6] Caged bearings were used more frequently during wartime steel shortages for bicycle wheel bearings married to replaceable cups.

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. Compared to other bearing types, the ball bearing is the least expensive, primarily because of the low cost of producing the balls used in the bearing.

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