Vane motor

The development of positive displacement downhole motors began in the late 1950s. The initial development was the result of a United States patent filed by W. Clark in 1957. This downhole motor was based on the original work of a French engineer, Rene Monineau, and is classified as a helimotor. The motor is actuated by drilling mud pumped from the surface. There are two other types of positive displacement motors that have been used, or are at present in use today the vane motor and the reciprocating motor. However, by far the most widely used positive displacement motor is the helimotor [79,83]. 

There have been some efforts over the past three decades to develop positive development vane motors and reciprocating motors for operation with drilling mud as the actuating fluid. These efforts have not been successful. 

In the early 1960s efforts were made in the United States to operate vane motors and reciprocating motors with compressed air. The vane motors experienced some limited test success but were not competitive in the market of that day [84]. Out of these development efforts evolved the reciprocating (compressed) air hammers that have been quite successful and are operated extensively in the mining industry and have some limited application in the oil and gas industry [85]. The air hammer is not a motor in the true sense of rotating equipment. The reciprocating action of the air hammer provides a percussion effect on the drill bit, the rotation of the bit to new rock face location is carried out by the conventional rotation of the drill string. 

The former works well with machines that have no nonreturn valve, whereas the latter acts on the screw shank and is used when braking is not possible. Various hydraulic drives are available, but vane motors, radial piston motors, and axial piston motors are preferred. Radial piston motors are used for screws with diameters of 50 to 200 mm ( 2 to 4 in) because they provide smooth operation. 

Example 2 Vibration Consider an electric motor rotating at 1800 rpm driving an 8-vane centrifugal pump rotating at 600 rpm. For this 3 1 speed reduction, assume a gear box having two gears of 100 and 300 tooth. Since 60 Hz is 1 rpm,... 

FIG. 12-48 Doiible-tnick dryer. (A) Air-inlet duct. (B) Air-exhaiist duct with damper. (C) Adjnstahle-pitch fan 1 to 15 hp. (D) Fan motor. (E) Fin heaters. (F) Plenum chamber. (G) Adjustable air-blast nozzles. (H) Trucks and trays. (J) Turning vanes. 

Tail gas expander without or with adjustable inlet guide vanes (11) and guide vane setting motor (12), labyrinth shaft seals with air sealing... 

Most of the drivers used with the sliding vane compressor are electric motors. Variable speed operation is possible within the limits of vane speed requirements. The vanes must travel fast enough to seal against the cylinder wall but not so fast that they cause excessive wear. For the smaller units, under 100 hp, V-belts are widely used. Direct connection to a motor, however, is possible for most compressors and is used through out the size range. 

Conventional methods of flow control used inefficient throttling devices such as valves, dampers, and vanes. These devices, although they have a low initial cost, introduce unacceptable running costs due to their inefficiency. Several speed control technologies can be used to improve motor system operation. 

Usually a constant speed, motor-driven compressor will be equipped with inlet guide vanes to the first wheel to allow suction volume control. If the guide vanes are not used, some other throtding device should be available. Figure 12-62 presents the constant speed performance of a centrifugal machine with inlet guide vanes. 

Curves B and C are for variable vane inlet dampening, and Curve A is for oudet dampening of a backward blade fan. Curve E shows an oudet damper with a multiple step speed slip-ring motor. This has an outlet damper for final control from 89-100%. From this graph, a reasonably accurate selection can be made of the control features to consider for most installation conditions. 

Fluid motors are usually classified according to the type of internal element which is directly actuated by the pressurized flow. The most common types of elements are gears, vanes and pistons. All three of these types are... 

The motors supplied with the rotary vane and rotary plunger pumps deliver enough power at ambient temperatures of 12 °C and when using our special oils to cover the maximum power requirement (at about 400 mbar). Within the actual operating range of the pump, the drive system of the warmed up pump needs to supply only about one third of the Installed motor power (see Fig. 2.11). 

Most fuzes now in use are armed by the action of an arming vane, such as shown in Fig 5-20. This action is similar to the action of a propeller, except that the vane is driven not by a motor but by the airstream during the bomb flight toward the target. 

For the surface modification of silica and carbon black, a radiofrequency (13.56 MHz) electrode-less tumbler plasma reactor at the University of Cincinnati was used. The schematic reactor design is shown in Fig. 5. It consists of a Pyrex cylinder chamber of 40 cm in length and 20 cm in diameter, with a motor-driven shaft at its center, and two vanes running in opposite directions. The reactor is based on a horizontal mixing principle and is capable of treating 350 g per batch. The powdery materials to be coated are placed at the bottom of the chamber. The plasma... 

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