Planetary Gear using Solidworks

An epicyclic gear train consists of two gears mounted so that the centre of one gear revolves around the centre of the other. A carrier connects the centres of the two gears and rotates to carry one gear, called the planet gear or planet pinion, around the other, called the sun gear or sun wheel.

Following inputs are considered for designing the Planetary Gear

Ring Gear

• Module = 2.5
• Number of teeth = 46

Sun Gear

• Number of teeth = 14

1. Input Speed of the Gear = 200 rpm.
2. Number of planet gears = 4

The dimensions of the carrier depend on the shaft diameter of the planet gear.

With the above input parameters, a simulation on the following cases is run

Input- Rotary Motion given to that part as input.

Output- After motion analysis, Angular Velocity of that part is plotted as a graph.

Fixed-Make that particular component as a fixed part.

You should not use the Gear Mate.The module is the same for all the gears.

You need to calculate the pitch circle diameter and the number of teeth for the planet gear.

In the first case when the input is given to the sun gear and output is obtained at the carrier keeping the ring gear fixed, the planet gear not only rotates about their axis but are also forced to roll on the inside of the ring gear along with the carrier as the Ring gear is fixed. The angular velocity obtained for this case is between 235-313 deg/sec.

In the second case when the input is given to the ring gear and output is obtained from the carrier keeping the sun gear fixed. The angular velocity achieved is maximum since the internal gear is big and planet gears are small comparatively so when a large gear meshes with a small gear the velocity achieved from the small gear is high because the velocity ratio is high. The angular velocity obtained for this case is between 800-1017 deg/sec.

In the third case, the carrier is fixed and output is to be obtained from the ring gear with the input given to Sun gear, all the gears rotate about their axis. The planet gears rotate only about their axis and transmit motion from sun to the ring and since the ring gear is big in diameter the angular velocity achieved is less. The deviations that are visible in the graphs show that there are points where sliding is occurring between the gears. For making the graph more smoother we can use precise contact. The angular velocity obtained for this case is around 340-402 deg/sec.