A hollow shaft encoder is a device or measuring machine. The instrument measures the values of a parameter. The hollow shaft converts the results in the form of electric impulses. The encoded parameters include travel, velocity, angular position, motion orientation, and revolution count. These factors vary as per the application system specifications. To learn more about the hollow shaft encoder, please check by the link.
Types of encoders
The encoders carry different rules of installation according to the nature of their application. The encoders come in two varieties –
- shaft encoder
- hollow shaft encoder
A shaft encoder consists of a rod that one can attach into an engine. The hollow shaft encoder needs an elastic tether that links it with a drive shaft. There is the availability of choice on mounting arrangements. There is no need to resize the feedback hardware with the dimensions of the actuator.
It is better to match the length and width of the rod to the motor dimensions to prevent misalignment. The accommodation of extra fittings like external mounting flange and flex couple can bring up an additional problem. These installations are easy to implement. They prevent misalignment problems as they have low sensitivity of vibrations and shock loads. The total dimensions of the assemblies in hollow-shaft remain small as they lack the need for external fittings.
Function of encoders
The shafted encoders offer incremental values, and the hollow shaft encoders provide absolute values. The induction engines that use alternating current can use the progressive mechanism. The direct-current brushless actuators require absolute sensing. The generation of pulse series in more than one stream creates an incremental response. The steps of the encoder in each turn determine the number of pulses from the starting point. The determination of the speed of rotation comes from the pulse frequencies.
Solution for motion direction
A single pulse stream can note the relative position and the monitor pace. But, it lacks the data about the direction of motion. The issue solves with the inculcation of another second stream with a relative offset of 90 degrees than the previous. The leading pulse stream can determine the direction of rotation. The production of zero pulses or so-called index on a third track originates from the incremental feedback mechanism. Precise count pulse reference comes from the third track.
Drawbacks of incremental encoders
Incremental encoders still have their disadvantages in spite of the cheap cost and simple architecture. These encoders do not determine the actual angular location at a point of time. But, they show the movement limit of an engine concerning an earlier point. The detectors are vibration-sensitive. With the drive towards maximum velocity, the resolution of these detectors can decrease. Post-power interruption, restoration is necessary for reference to the similar starting point with the reference drive.
The hollow shaft encoders are measuring instruments that use electric pulses to measure specific parameters. These devices can calculate the settings in their encoded format with the help of their mechanisms.