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Ball Spline
Ball splines (Ball Spline Bearing (mechanical), bearings) are a special type of linear motion bearing that are used to provide nearly frictionless linear motion while allowing the member to transmit torque simultaneously. There are Groove (engineering), grooves ground along the length of the shaft (thus forming Rotating spline, splines) for the ball bearings to run inside. The outer shell that houses the balls is called a nut rather than a Bushing (bearing), bushing, but is not a nut in the traditional sense—it is not free to rotate about the shaft, but is free to travel up and down the shaft. For a shaft travel of any significant length the nut will have channels that recirculate the balls, operating in the same way as a ball screw. By increasing the contact area of the ball bearings on the shaft to approximately 45 degrees, the side load and direct load carrying capabilities are greatly increased. Each nut can be individually Preload (engineering), preloaded at the factory to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearing (mechanical)
A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis; or, it may ''prevent'' a motion by controlling the vectors of normal forces that bear on the moving parts. Most bearings facilitate the desired motion by minimizing friction. Bearings are classified broadly according to the type of operation, the motions allowed, or to the directions of the loads (forces) applied to the parts. Rotary bearings hold rotating components such as shafts or axles within mechanical systems, and transfer axial and radial loads from the source of the load to the structure supporting it. The simplest form of bearing, the ''plain bearing'', consists of a shaft rotating in a hole. Lubrication is used to reduce friction. In the ''ball bearing'' and ''roller bearing'', to reduce sliding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Motion Bearing
A linear-motion bearing or linear slide is a bearing designed to provide free motion in one direction. There are many different types of linear motion bearings. Motorized linear slides such as machine slides, X-Y tables, roller tables and some dovetail slides are bearings moved by drive mechanisms. Not all linear slides are motorized, and non-motorized dovetail slides, ball bearing slides and roller slides provide low-friction linear movement for equipment powered by inertia or by hand. All linear slides provide linear motion based on bearings, whether they are ball bearings, dovetail bearings, linear roller bearings, magnetic or fluid bearings. X-Y tables, linear stages, machine slides and other advanced slides use linear motion bearings to provide movement along both X and Y multiple axis. Rolling-element bearing A rolling-element bearing is generally composed of a sleeve-like outer ring and several rows of balls retained by cages. The cages were originally machined from soli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groove (engineering)
In manufacturing or mechanical engineering a groove is a long and narrow indentation built into a material, generally for the purpose of allowing another material or part to move within the groove and be guided by it. Examples include: # A canal cut in a hard material, usually metal. This canal can be round, oval or an arc in order to receive another component such as a boss, a tongue or a gasket. It can also be on the circumference of a dowel, a bolt, an axle or on the outside or inside of a tube or pipe etc. This canal may receive a circlip, an o-ring, or a gasket. # A depression on the entire circumference of a cast or machined wheel, a pulley or sheave. This depression may receive a cable, a rope or a belt. # A longitudinal channel formed in a hot rolled rail profile such as a grooved rail. This groove is for the flange on a train wheel. Grooves were used by ancient Roman engineers to survey land. See also * Fluting (architecture) * Gland (engineering) * Glass ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotating Spline
Splines are ridges or teeth on a drive shaft that matches with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them. For instance, a gear mounted on a shaft might use a male spline on the shaft that matches the female spline on the gear. The splines on the pictured drive shaft match with the female splines in the center of the clutch plate, while the smooth tip of the axle is supported in the pilot bearing in the flywheel. An alternative to splines is a keyway and key, though splines provide a longer fatigue life, and can carry significantly greater torques for the size. Types There are several types of splines: ;Parallel key spline: where the sides of the equally spaced grooves are parallel in both directions, radial and axial. ;Involute spline: where the sides of the equally spaced grooves are involute, as with an involute gear, but not as tall. The curves increase strength by decreasing stress concentrations. ;Crowned spl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bushing (bearing)
A plain bearing, or more commonly sliding contact bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing), is the simplest type of bearing, comprising just a bearing surface and no rolling elements. Therefore, the journal (i.e., the part of the shaft in contact with the bearing) slides over the bearing surface. The simplest example of a plain bearing is a shaft rotating in a hole. A simple linear bearing can be a pair of flat surfaces designed to allow motion; e.g., a drawer and the slides it rests on or the ways on the bed of a lathe. Plain bearings, in general, are the least expensive type of bearing. They are also compact and lightweight, and they have a high load-carrying capacity. Design The design of a plain bearing depends on the type of motion the bearing must provide. The three types of motions possible are: * ''Journal'' (''friction'', ''radial'' or ''rotary'') ''bearing'': This is the most common type of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball Screw
A ball screw (or ballscrew) is a mechanical linear actuator that translates rotational motion to linear motion with little friction. A threaded shaft provides a helical raceway for ball bearings which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction. They are made to close tolerances and are therefore suitable for use in situations in which high precision is necessary. The ball assembly acts as the nut while the threaded shaft is the screw. In contrast to conventional leadscrews, ballscrews tend to be rather bulky, due to the need to have a mechanism to recirculate the balls. Another form of linear actuator based on a rotating rod is the threadless ballscrew, a.k.a. "rolling ring drive". In this design, three (or more) rolling-ring bearings are arranged symmetrically in a housing surrounding a smooth (threadless) actuator rod or shaft. The bearings are set at an angle to the rod, and this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball Bearing
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. History Although bearings had been developed since ancient times, the first mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preload (engineering)
Preload is an engineering term with several meanings. In the general sense, it refers to the internal application of stress to certain mechanical systems. Fastener preload ' The most common usage is to describe the load applied to a fastener as a result of its being installed, i.e., before any external loads are applied (e.g., tightening the nut on a bolt). Preload in such cases is important for several reasons. First, a tightened bolt experiences only a small fraction of any external load that will be applied later, so that a fully tightened bolt can (depending on the exact application) sustain a much greater load than a loosely tightened bolt. Second, a nut that is correctly tightened will resist becoming loose under the influence of vibration, temperature cycling, etc. Bearing preload Internal stress to a bearing through application of negative clearance is known as bearing preloading. Advantages of preloading include the following: maintain axial and radial position for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
