Shaft alignment mounting

Laser alignment systems use a transmitter and receiver. The system has a laser diode and a position sensor on a bracket mounted on one shaft that emits a weak and safe radio-tagged beam of light. The light ray is directed toward the other bracket on the other shaft with a reflecting prism that returns the ray back toward the first bracket into the position sen.sor eye. 

At Pump Installation Be sure the motor shaft centerline is below the pump shaft centerline so that it can be shimmed upward. Make sure the motor mount boltholes have sufficient play to allow for some lateral adjustment. Many pumps and motor assemblies are shipped from the factory on a common channel iron base plate. The manufacturer alleges that they arc already aligned at the factory. You need to verify and correct this alignment in all cases. 

Note that this offset value is not the true theoretical offset. It is actually the theoretical offset plus one-half of the shaft diameter (see Figure 54.5) because the indicator dial is mounted on the outside edge of the shaft as opposed to the centerline. However, for the purposes of alignment calculations, it is not necessary to use the theoretical offset or the theoretical run that corresponds to it. Figure 54.7 illustrates why this is not necessary. 

While the dial-indicator and optical methods differ in the equipment and/or equipment setup used to align machine components, the theory on which they are based is essentially identical. Each method measures the offset and angularity of the shafts of movable components in reference to a pre-selected stationary component. Each assumes that the stationary unit is properly installed and that good mounting, shimming, and bolting techniques are used on all machine components. 

Note that rim-and-face alignment cannot be used when there is any end play, or axial movement, in the shafts of either the stationary or movable machine-train components. Since the dial indicator that is mounted parallel to the shaft is used to measure the angularity of the shafts, any axial movement or float in either shaft will distort the measurement. 

These microprocessor-based systems automatically calculate correction factors. If the fixtures are properly mounted and the shafts are rotated to the correct positions, the system automatically calculates and displays the appropriate correction for each foot of the movable machine-train component. This feature greatly increases the accuracy of the alignment process. 

A hot alignment check is performed exactly like an ambient alignment check with the added safety precautions required for hot machinery. The accuracy of a hot alignment check depends on how soon after shutdown dial indicator readings can be taken. Readings may be taken within a few minutes with the use of shaft-mounted brackets that span a flexible coupling. To speed up the process, assemble the brackets to the fullest extent possible prior to shutdown so that they need only be bolted to the shafts once the machine stops rotating. 

The turret head is fixed to the main shaft of the gear box. It is manufactured in two pieces (upper and lower) which guarantee the alignment between punches and dies. The gear box is mounted on the lower section under the die table and is responsible for transmitting the draft movement of the motor toward the turret head. 

The distribution of molecular speeds can be danonstrated with the apparatus shown in Figure 5.18. A beam of atoms (or molecules) exits from an oven at a known temperature and passes through a pinhole (to collimate the beam). Two circular plates mounted on the same shaft are rotated by a motor. The first plate is called the chopper and the second is the detector. The purpose of the chopper is to allow small bursts of atoms (or molecules) to pass through it whenever the slit is aligned with the beam. Within each burst, the faster-moving molecules will reach the detector earlier... 

In minor cases, alignment can be corrected by removing the motor from its mount, loosening the screws that hold the motor mounting block, and then aligning the block with the shaft. An alignment tool helpful in this process can be obtained from Western Technology if necessary. 

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