Radial bearings

Radial Bearings Antifriction bearings are largely unsuitable for these applications, chiefly because of the special attention and maintenance which they demand.  [c.2521]

Figure 2-11 illustrates the potential severity of three problems that tend to eorrelate turboexpander inlet pressure thrust bearings, erosion of rotor and nozzles, and radial bearings.  [c.33]

The radial and thrust bearings shall be equipped with resis-tanee temperature deteetors (RTDs). Eaeh radial bearing shall have two embedded RTDs, and eaeh side of the thrust bearing shall have two embedded RTDs. The RTDs shall be 100 at 0°C, platinum with dual element. The RTDs shall be loeated at positions in the bearings where the highest temperature is antieipated. They shall be terminated in loeal junetion boxes suitable for housing the RTD/mA transmitters working on a 4-20 mA signal.  [c.315]

Operating Principles and Design Features Radial Bearings  [c.335]

Figure 6-3. Basic radial bearing configurations. Figure 6-3. Basic radial bearing configurations.
An active magnetic axial bearing consists of two stators and a rotor disk (Figure 6-4). A sensor located at the end of the shaft monitors and maintains the rotor position between the two stators. The principle of operation is the same for both axial and radial bearings any deviation from the normal position of the rotor is communicated to the electronic control system, which adjusts the electric current going to the electromagnets to correct the rotor position.  [c.336]

Active magnetic bearings attain speeds up to 200 m/s (656 ft/sec) on radial bearings, and 350 m/s (1,148 ft/sec) on axial or thrust bearings. A large variety of process fluids are allowed to flood or surround these bearings. Allowable operating temperatures range from -253°C (-420°F) to as high as +450°C (+840°F). There is no measurable friction and vibration is rarely experienced.  [c.337]

Magnetic bearings (Figure 8-7) were discussed in Chapter 6. The operating principle can be restated by noting that the rotor assembly is suspended, or levitated, in a magnetic field generated by radial bearings at each end. Axial position is maintained by a thrust bearing located either in the center or at one end of the rotor. When the magnetic bearings are deenergized, auxiliary bearings at each end of the shaft provide support. These auxiliary bearings are dry, or non-lubricated, and remain unloaded during normal operation. Once the magnetic bearings are energized, an electronic control system centers the shaft within the field and uses signals from sensors to control the current, and hence magnetic flux.  [c.457]

Each aspect of the turboexpander s bearing systems was carefully tailored. For instance, the radial bearings for Norske Shell were built larger—200-mm (7.88-in.) in diameter—than required to provide additional overload capacity. Axial thrust was contained by a doubleacting magnetic thrust bearing using the thrust disk concept that has seen decades of satisfactory use in traditional high-capacity turbomachinery bearings.  [c.458]

In a eompressor with a vaned diffuser followed by a typieal easing, the non-uniform, eireumferential flow resistanee aeross the diffuser walls induees an asymmetrie gas pressure around the wheel. Non-uniform peripheral gas pressure results in unbalaneed loading on the wheel and, henee, a radial bearing load.  [c.482]

The double amplitude of unfiltered vibration in any plane measured on the shaft adjacent to each radial bearing is not to exceed 2.0 mils (0.05 mm) or the value given by  [c.165]

There are many roller bearing types. They are differentiated aeeording to the direetion of the main radial loads (radial bearings) or axial loads (thrust  [c.470]

Radial Bearing Tlirust Bearing  [c.471]

The load rating of a radial bearing is defined by radial loads whereas that of a thrust bearing is defined by axial loads. Every rolling bearing has a dynamie load rating and a statie load rating. The terms dynamie and statie refer to the movement of the bearing but not to the type of load.  [c.475]

Proeess flow measurement at inlet or diseharge of maehine Radial-bearing temperature thermoeouple or resistanee temperature element embedded in eaeh bearing, or temperature at lube oil diseharge of eaeh bearing.  [c.661]

Bearing failures are one of the major eauses of failures in turbomaehinery. The ehanging of various types of radial bearings from eylindrieal and/or  [c.739]


In the larger, dry process compressors, the radial bearings are of the sleeve or tilting pad type. Bearing surfaces use a high tin babbitt on a steel backing. API 619 requires the bearings to be removable without removing the rotors or the upper half on the horizontally split machine Thrust bearings are generally tilt pad type, though not necessarily symmetric. On standardized compressors for air or refrigeration, the bearings are normally the rolling element type. Some standardized dry compressors use a tapered land thrust bearing. Most of the flooded compressors and some of the standardized dry compressors use rolling element thrust bearings. In all cases, the bearings are pressure-lubricated with some compressors using the gas differential pressure to circulate the lubricant  [c.116]

The liquid film seal uses metallic sealing rings and is liquid buffered to maintain a fluid film in the clearance area and thereby preclude gas leakage. It is not unusual in the screw compressor to find the radial bearing and seal combined.  [c.117]

Radial bearings or journal bearings are usually pressure-lubricated. Most compressors use two bearings on opposite ends of the rotor assembly or on  [c.197]

The magnetic bearing is made up of a series of electromagnets located circumferentially around the shaft to form the radial bearing. The electromagnets (Figure 5-42) are laminated to limit the eddy current losses. The shaft must be fitted with a laminated sleeve (see Figure 5-43) for the  [c.205]

Turbine speeds are limited by the centrifugal stress that can be applied to the blades and blade roots. For a 3,000-hp turbine, a speed of about 14,000 rpm can be expected, but a speed of only 8,000 rpm can be expected from a 10,000-hp turbine. Higher horsepowers and speeds can be obtained in special turbines, and are frequently specified for large centrifugal compressors. These turbines need very careful checking for lateral critical speeds, torsional critical speeds, radial bearing stabilities, thrust bearings, balance, and permissible flange loadings.  [c.284]

Figure 8-27. Typical radial bearing temperature sensor installation. Figure 8-27. Typical radial bearing temperature sensor installation.
Figure B-29. Radial bearing with a temperature sensor installed. Courtesy of A-C Compressor Corporation) Figure B-29. Radial bearing with a temperature sensor installed. Courtesy of A-C Compressor Corporation)
Radiol Bearing Ball Type  [c.164]

The rotors are eccentric in their rotation at the bottom of the motor section. Thus, the connecting rod section provides a flexible coupling between the rotor and the main drive shaft located in the thrust and radial bearing section. The main drive shaft has the drill bit connected to its bottom end.  [c.885]

The thrust and radial-bearing section contains the thrust bearings that transfer the weight-on-bit to the outside wall of the positive displacement motor. The radial support bearings, usually located above the thrust bearings, ensure that the main drive shaft rotates about a fixed center. As in most turbine motor designs, the bearings are cooled by the drilling fluid. There are some recent positive displacement motor designs that are now using grease-packed, sealed bearing assemblies. There is usually a smaller upper thrust bearing that allows rotation of the motor while pulling out of the hole. This upper thrust bearing is usually at the upper end of thrust and radial bearing section.  [c.885]

Install the dial indicator as close to the radial bearing as possible. Lift the shaft or exert light pressure at the impeller end. If more than 0.002 to 0.003 inches of radial movement occurs, investigate bearings and bearing fits (especially the bore) for the radial bearing fit. An oversized radial bearing bore caused by wear, improper machining, or corrosion will cause excessive radial shaft movement resulting in  [c.950]

Extreme wear at the mating contact faces will occur when excessive shaft whip or deflection is present due to defective radial bearings or bearing fits. The contact area of the mating faces will be increased, resulting in increased wear and the elimination or reduction of the lubricating film between the faces, further shortening seal life.  [c.951]

Although many bearings perform more than one function, they can generally be classified based on types of movement and there are three major classifications of both plain and rolling element bearings radial, thrust, and guide. Radial bearings support loads that act radially and at right angles to the shaft centerline. These loads may be visualized as radiating into or away from a center point like the spokes on a bicycle wheel. Thrust bearings support or resist loads that act axially. These may be described as endwise loads that act parallel to the centerline towards the ends of the shaft. This type of bearing prevents lengthwise or axial motion of a rotating shaft. Guide bearings support and align members having sliding or reciprocating motion. This type of bearing guides a machine element in its lengthwise motion, usually without rotation of the element.  [c.1007]

Common functional groupings of ball bearings are radial, thrust, and angular-contact bearings. Radial bearings carry a load in a direction perpendicular to the axis of rotation. Thrust bearings carry only thrust loads, a force parallel to the axis of rotation tending to cause endwise motion of the shaft. Angular-contact bearings support combined radial and thrust loads. These loads are illustrated in Figure 60.8. Another common classification of ball bearings is single row (also referred to as Conrad or deep-groove bearing) and double row.  [c.1012]

Plain radial bearing, inlet end  [c.49]

Top-Suspended Centrifuges The top-suspended centrifuge (also known as a pendulum centrifuge, see Fig. L8-146) is widely used for purging molasses from crystallized sugar, as well as for many other apphcations. Conventionally, the drive is suspended from a horizontal bar supported at both ends from two A-frames. The drive head, which is connected to the motor or a driven pulley through a flexible coiiphng, carries the thrust and radial bearings that support the shaft and its load. The cylindrical bowl has a ring weir at the top. The stationary casing is attached to the A-frame. The filtrate is collected and diverted to an outlet in the casing.  [c.1736]

The radial bearings shall be designed to suppress hydro-dynamie instabilities and provide suffieient damping over the entire range of allowable bearing elearanees to limit rotor vibration to the maximum speeified in this doeument at the speeified operating ranges. The radial bearings shall be of the tilting pad or flexure pivot type in horizontally split housings. If the Seller quotes sleeve-type radial bearings as an option, the bearing housing shall be designed for field installation of the tilting pad-type radial bearings without any remaehining of the bearing housing.  [c.314]

Two non-eontaeting proximity probes positioned at 90° shall be supplied at eaeh radial bearing. The probes shall be supplied eomplete with proximitors and intereonneeting wires.  [c.314]

The two recognized standard sensors are the ISA type J thermocouple (iron-constantan) and the 100 ohm at 0°C platinum 3-wire RTD. Additional attributes such as TFE insulation and stainless overbraid are specified. The sensors are installed in a drilled hole at the location shown, with the objective being to place the sensor approximately. 030 inches to the rear of the base of the babbitt. Surprisingly, steel conducts at approximately the same coefficient as the babbitt, so there is no significant temperature drop at the metal interface. The sensor is potted in place, with some of the over braid included, to provide strain relief. An alternate to potting is to use a spring and clip arrangement, which has the advantage of an easy sensor replacement. Figure 8-29 shows a radial bearing with a temperature sensor installed. Figure 8-30 depicts an instrumented thrust bearing.  [c.345]

In general, the downhole positive displacement motor constructed on the Moineau principle is composed of four sections (1) the dump valve section, (2) the multistage motor section, (3) the connecting rod section and (4) the thrust and radial-bearing section. These sections are shown in Figure 4-202. Usually the positive displacement motor has multichambers, however, the number of chambers in a positive displacement motor is much less than the number of stages in a turbine motor. A typical positive displacement motor has from two to seven chambers.  [c.883]

Radially spHt constmction is typically a diffusor design, offering the advantage of reduced radial thmst, which is better from the standpoint of lowering shaft deflections, resulting in longer Life of seals and bearings. The reason for radial thmst reduction is an inherent geometrical symmetry of the diffusor (having multiple vanes), which results in uniform pressure distribution at the impeller periphery. The volute design has an uneven pressure distribution, which results in radial load. The double volute has two tongues, called cutwaters, which, as compared to a single volute, results in more uniform pressure distribution around the impeller periphery. This distribution is not as uniform as in a diffusor design. The disassembly of the diffusor pump is more involved because a complete pump must be discoimected from the piping for service. Both designs are limited to temperatures around 175°C (350°F), as deterrnined by gasket sealing and safety considerations. For more critical and higher temperature appHcations such as boiler feed services and refinery appHcations of volatile or hot (>175°C) temperatures, a segmental ring design is enclosed into a cast or forged barrel, which becomes a pressure-containing vessel having a fully confined gasket. This gasket seals the ends via suction and discharge heads.  [c.294]

See pages that mention the term Radial bearings : [c.2480]    [c.2534]    [c.35]    [c.319]    [c.321]    [c.197]    [c.167]    [c.884]    [c.900]   
Compressors selections and sizing (1997) -- [ c.0 ]