The process of producing damped oscillation of Gyro and its various phases are as follows:
By adding an additional weight to the lower part of the Gyro sphere, We can provide it the pendulum effect. This is done by placing a damper (with two pots, one at each end of the damper) partially filled with oil at the Gyro poles. Accordingly, This oil damper makes the Gyro sphere pendulous and thus the gyro starts settling down following a spiral way.
When the axis of gyro is parallel to the axis of Earth’s rotation, that time the deflection of the pendulous moment or Gyro from the axis will be highest. At this time, the difference between the level of both vessels of damper will be highest.
In this condition, we can see 03 types of precession here:
- Precession rate due to the moment of pendulum.
- Precession rate due to the change in axis of Gyroscope.
- Precession rate due to the additional weight of damper.
Diagram showing the change in axis positions:
At condition I
The axis of Gyro is parallel and the north corner moves by ‘L’ angle towards east of meridian.
The damper has oil in its both (north side and south side) pots. However in this condition, the level of oil in north pot will be higher than level of oil in south pot. This is because of the direction of movement and the rate of tilt.
At condition II
At this condition, a small quantity of oil starts to shift from north pot to south pot of damper. When the balance between the two pots starts to improve, it results in limiting the moment restriction due to the oil damper.
This moment effected by the damper and the momentum of pendulous effect on Gyro are in similar direction. Due to this, the precession of north corner of Gyro is even more quicker at condition II.
At condition III
In this position, the axis of Gyroscope aligns with the main meridian. Here, at this juncture, the level of oil of both pots of damper will be same. Accordingly, the moment effected by the damper will be at its minimum (Zero). However, the momentum of pendulous effect of Gyro at this condition will be at its maximum. And thus, the gyro crosses the meridian and moves ahead instead of settling at meridian.
At condition IV
The level of oil in south pot of damper will start increasing now. This will give a damping effect to the momentum of axis of Gyroscope. Accordingly, the axis will precess to meridian again.
At this point, the momentum due to pendulous effect of Gyro and the momentum due to the increase in weight of south pot of damper will oppose to each other. `
At condition V
At this point, the level of oil in the south pot of the damper will be at its highest level. At this case the momentum due to the damper weight will be at its maximum. This will overcome the momentum of pendulous effect of Gyroscope.
The axis of gyro will be in line with the horizontal plane.
At condition VI
In this condition, the level of oil in south pot of damper will start to shift towards the north pot. And so, the momentum due to the damper weight will also start decreasing. However, the Gyro will keep on precessing towards east due to the pendulous moment.
At condition VII
In this point, the axis of Gyroscope will be in line with meridian. The level of oil in both the pots will be similar. Accordingly, the momentum due to the damper weight will be at its minimum (Zero).
The Gyroscope is still under influence of pendulous effect. And so, it will cross the meridian again, in spite of settling at meridian. However, this time, the movement of the axis of gyroscope will be very slow.
At condition VIII
At this point, the level of oil will be more in north pot of the damper. Therefore, the momentum due to the damper weight will be in opposition of the momentum of the axis of Gyroscope. Accordingly, the movement of Gyroscope axis is damped even more. The same minor fluctuation of the axis of Gyroscope from meridian will be damped again and finally the axis of Gyro will settle at meridian