Planetary Gear

AIM

 The aim of this challenge to model the carrier part of the Planetary gear train assembly ie; (get the sun gear, planet gear, ring gear)from the toolbox and to assemble them in the right way to do the motion analysis and fetch the required results in form of plots with the different inputs and to get output from the given and also as simulations.

INTRODUCTION

 Each and every part of the assembly is got from the toolbox as per the given dimensions and also the calculation for the missed ones are made, except for the carrier part which is modeled by our own dimensions matching up the planetary gears, after which they are bought to assembly and they are set up in a way that each and every part is its position with respect to the other one so that the simulation and the motion study works fine in order to the get the results as expected.

MODELING PROCESS:

Calculation:

  So according to the given challenge, we have to find the pitch circle diameter and the number of teeth for the planet gear where the given details are,.

• Ring Gear
  • Module = 2.5 
  • Number of teeth = 46
• Sun Gear 
  • Module = 2.5 
  • Number of teeth = 14

  So from the video, it said that module is the ratio of pitch circle diameter to the number of teeth.

mathematically represented as,

module = pitch circle diameter / Number of teeth.  ------Formula 1

  From this we were able to find;

• Ring Gear
  • Pitch circle diameter = 115mm
• Sun Gear 
  • Pitch circle diameter = 35mm 

And to find the Pitch circle diameter of the planetary gear we have to use the above pitch circle diameters of the ring gear and sun gear, where when we subtract these both we get 80mm since it is for half of the value when divided by 2 we get the pitch circle diameter of planetary gear as 40mm.

And by using module and pitch circle diameter, we can use Formula 1  and calculate the number of teeth.

  So the result is:

• Ring Gear
  • Pitch circle diameter = 40mm
  • Number of teeth = 16

Part 1 - Ring Gear

To start firstly the assembly file is opened not the part file since due to some issued in giving parameters for the gears from toolbox we get the gears from ANSI Metric, select power transmissions, gears, and select Ring gear and place it on the assembly and edit the parameters, where the parameters such as module, pressure angle, no of teeth, diameter, and face width are given, of which few are taken from the above calculation.

https://drive.google.com/file/d/1sqhwahTfGDMiKk79bWwBF6VApafQzvYR/view?usp=sharing 

Part 2 - Sun Gear

To start firstly the assembly file is opened not the part file since due to some issued in giving parameters for the gears from toolbox we get the gears from ANSI Metric select power transmissions, gears, and select Spur gear and place it on the assembly and edit the parameters, where the parameters such as module, pressure angle, no of teeth, diameter, and face width are given, of which few are taken from the above calculation.

https://drive.google.com/file/d/1_-Qs0NOmqGeNU13zst4gbIxjuGdO41OM/view?usp=sharing 

Part3 - Planetary Gear

To start firstly the assembly file is opened not the part file since due to some issued in giving parameters for the gears from toolbox we get the gears from ANSI Metric select power transmissions, gears, and select Spur gear and place it on the assembly and edit the parameters, where the parameters such as module, pressure angle, no of teeth, diameter, and face width are given, of which few are taken from the above calculation.

https://drive.google.com/file/d/1Izrrioi97yBv6O3k0bc-4QjGLOI38dFV/view?usp=sharing 

Part 4 - Carrier

  To model this carrier for these 4 planetary gears, firstly the sketch is created by having the dimensions of the planetary gear and also the sun gear so that the shaft of the required size is got, after which all the 4 shafts are extruded, then a plate-like structure is drawn for the support of the output from the four-shaft to a single shaft to behold in place, then those sketches are also extruded to the needed limits.

https://drive.google.com/file/d/1PtFYtMBSHiVHXatTUKKTnpVQyF3RldXX/view?usp=sharing 

ASSEMBLY PROCESS:

Firstly the all the parts from toolbox are made into separate new part files and saved in order to create an assembly with full access in our hands, and as said the first part is ring gear on the assembly plane this ring gear is made to mate with the planes on the assembly tree so that the ring gear can only rotate and not translate. Then the sun gear is imported, similarly, the mates are provided in such a way that the sun gear is fixed in the center of the ring gear and it can only rotate and not move freely, after which the planet gears are imported in the assembly but no mates are provided to them since the carrier is created in this challenge these planet gears are going to be in relation with the carrier, so the carrier is imported into the assembly and the center is made fixed with the center of the ring gear and the mates are given in relation to the planetary gears and also with the ring gear in such a way that the carrier rotates only in the ring gears axis where the planet gears follow the carrier. So in this way the assembly is perfectly made for the simulation to take place.

https://drive.google.com/file/d/1HRfHC9amWLG5KVC1tN0P85IOABhiafUt/view?usp=sharing 

MOTION STUDY SETUP:

The term motion study is referred to as the study of the behavioral aspects of any mechanism or machinery with respect to the inputs given the inputs can vary with respect to project or part, and also the analysis of the output is done at the same time it can be got as a plot from the entities we provide or from the outputs generated.

   Now let's go into the procedure to do the motion study setup, Here we are going to perform this motion study on the Planetary gear train assembly for which firstly the motion addon is selected from Solidworks add-in's and then in the bottom bar we go to new motion study and select the motion analysis from the dropdown, then we proceed on, firstly the motor with required RPM is set on the input as specified on the challenge by selecting its temporary axis and after which the contacts are given, then the part to be fixed as given in the challenge is fixed and when doing so there may be few effects of over defining so in order to overcome them few mates are made to suppress and then the simulation is done, similarly all the three types of simulation and its output are given below.

PLOT 1:

Input-Sun Gear

Output-Carrier

Fixed-Ring Gear

Angular Velocity of Carrier

  The above plot is obtained from the motion study of Planetary Gear train assembly where after the simulation of the working the results are made to be a plot with given specifications ie

-Displacement/velocity/acceleration

-angular velocity

-Magnitude

and so we get the above plot where the axis is defined as

Y-axis(angular velocity in deg/sec), X-axis(Time in sec)

 OBSERVATION AND RESULT

 From the above graph, it is known that the angular velocity of the carrier when the ring gear is fixed has a value of around or above 292 deg/sec but as we know that we have given the input as 200 RPM, and when we see the graph there is a steep increase in velocity at the beginning but as time goes on it gets as a constant value but with a very slight deviation. So this is caused due to the gear ratio between these gears and can also be an influence of pitch circle diameter and also the number of teeth.

PLOT 2:

Input-Ring Gear

Output-Carrier

Fixed-Sun Gear

Angular Velocity of Carrier

The above plot is obtained from the motion study of Planetary Gear train assembly where after the simulation of the working the results are made to be a plot with given specifications ie

-Displacement/velocity/acceleration

-angular velocity

-Magnitude

and so we get the above plot where the axis is defined as

Y-axis(angular velocity in deg/sec), X-axis(Time in sec)

OBSERVATION AND RESULT

From the above graph, it is known that the angular velocity of the carrier when the Sun gear is fixed has a value of around or above 901 deg/sec but as we know that we have given the input as 200 RPM, and when we see the graph there is a steep increase in velocity at the beginning where it reaches up to a value of 1202 deg/sec and then it got reduced to the appropriate value and got to be a constant value as time moves on, with a very slight deviation. So this is caused due to the gear ratio between these gears and can also be an influence of pitch circle diameter and also the number of teeth.

PLOT 3:

Input-Sun Gear

Output-Ring Gear

Fixed-Carrier

Angular Velocity of Ring Gear

The above plot is obtained from the motion study of Planetary Gear train assembly where after the simulation of the working the results are made to be a plot with given specifications ie

-Displacement/velocity/acceleration

-angular velocity

-Magnitude

and so we get the above plot where the axis is defined as

Y-axis(angular velocity in deg/sec), X-axis(Time in sec)

OBSERVATION AND RESULT

 From the above graph, it is known that the angular velocity of the ring gear when the carrier is fixed has a value of around or above 380 deg/sec but as we know that we have given the input as 200 RPM, and when we see the graph there is a steep increase in velocity at the beginning but as time goes on it gets as a constant value but with a very slight deviation. So this is caused due to the gear ratio between these gears and can also be an influence of pitch circle diameter and also the number of teeth.