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Hello.
Our Today’s tutorial is a design of planetary gearbox. As you see this is our required gearbox:
this is the input shaft and this is the output shaft. We achieve a gear reduction in this
gearbox, for example, if a certain RPM is given at this shaft, the output shaft will
result in a reduced RPM and high torque. What happens inside this gearbox? Let me show you
by showing the section view. Okay, this is the section view of planetary gearbox. We
can see that it has 4 stages. By stages we mean it has 4 epicyclic systems and the gears
shown in yellow are called the internal gears or the ring gears. As you can see that there
are 4 ring gears that makes it 4 stage reduction gearbox (reduction planetary gearbox). The
power comes from this input shaft. This input shaft drives this sun gear. We call the central
gear of every stage the Sun gear. The sun gear tends to rotate the planets around it.
Let us open this stage in a separate window. Okay. This is only the input shaft. This input
shaft drives the sun gear. Let me show you how the sun gear is connected in the first
stage assembly. Let me open the stage one. Okay this is the stage one. I will show you
how every stage works. This stage at the moment is not including the input shaft. Let me also
import the input shaft to this. We import this low speed gearbox and insert this input shaft into this stage
one, just to demonstrate what happens in every stage. Okay, here comes our input shaft. The
power comes from here, from this input shaft, this input shaft rotates. This makes these
planets rotate. The outer sun gear or the internal gear is bolted to an external case
which is fixed. So, this tends to rotate these pinions. These pinions start working inside
this ring gear. Okay. Now, due to rotation of these planets, this arm rotates. This arm
is bolted to the output shaft and as a result, output shaft rotates. This gives some reduction
in the speed. Now, by stages, I mean. Now let me show you what happen in the stages.
The first input comes from here. From here, the output is obtained. This output becomes
the input of second stage and this is the output of second stage. The output of second
stage becomes the input of third stage and output of third stage becomes the input of
fourth stage. The output of fourth stage is our final output. Now, I will first show you
the design of single stage. We will then assemble the other stages directly from this assembly.
I will show how to independently design an epicyclic gear train. Okay. Where to start
the basic step of designing the planetary gear train is the kinematic design. You should
have an idea how much reduction you want to achieve in a single stage. Okay. We go to
New part. Make a sketch on the Front plane. Just I am giving a small example of kinematic
design. Let us assume that 80 millimeters is the radius of outer gear so the diameter
comes out to be 160 millimeters. Let’s say this is the pitch diameter of ring gear. The,
this is the pitch diameter of sun gear. Let’s say this is 80. So what is the distance between
these two? This is 40 millimeters. So the diameters of the sun gear should be 40 millimeters.
That’s how the planet gears rotate around the sun. Okay. Now I will show you the use
of toolboxes. Let us now make the use of toolbox. We go to the ANSI metric standard -> power
transmission -> gears, let’s say we pick “Spur gear” as spur gears are used. Give
me a moment as it should be done in an assembly environment. Okay. So let us introduce a spur
gear here. Let’s say we take its module 1, being an engineer you must have knowledge
about the modules, the AGMA Standards. I am assuming that this course is for gear design
particularly and the engineers are watching this video. I am assuming that you are already
familiar with the module system. I do not want to go into the details of module as I
have to cover the whole assembly in this one tutorial. Okay. Let us have the number of
teeth of this sun gear be 80. Now we will keep the teeth ratio according to the pitch
diameters we calculated earlier. Okay. It has 80 teeth. Now I will import the ring gear.
In that ratio the ring gear should have 160 teeth. And its outside diameter should be
greater than 160, make it 170 for now. Like so. Done. We will mate their faces in one
plane, make them concentric. Now I will add an axis using the reference geometry and selecting
any 2 planes. I would prefer top plane and front plane. The axis appears. Now, to show
the axis, I mate the axis of this gear and the axis I just created. Okay, it says it
is fully defined. I just forgot to remove this fixed constraint from the gear. I click
on float and then I try to mate them again. Now when I mate these axes, it comes to this
position. Okay. Now, I mate its face with this plane. This is right plane. Okay. Fine.
Now, let us recall what did we calculated, the radius of planet gears. The radius of
planet gears was 40 millimeters in diameter. Let’s say if I make it 40 millimeters, being
in 1st module, the pitch diameters exactly equal to number of teeth. So, 40 mm corresponds
to 40 number of teeth. This is only valid if I select the module 1. With the module
3, it gives the triple size with the same number of teeth and with the module 4; it
gives four time bigger size with the same number of teeth. Module is basically the ratio
of pitch diameter divided by the number of teeth. So for module 1 the pitch diameter
and number of teeth are same. Okay. Let’s have module 1 and number of teeth be 40. Okay.
Now you observe that this size exactly fit inside these 2 gears. Okay. Now, we need some
method to constraint its circle, just like in this region. I mean for example, on right
plane, the gear must be rotating at the circle which is the mean of the two diameters. It
should be, the mean comes out to be, 120 mm. okay. Now the center of this circle stays
at, this imaginary circle I created. The mechanism would function as it is desired. For that
purpose, we create the arms. Now, the arms which are connected to the output shaft. We
mate planes. Now in order to create the arms, I make a new part right here. Just trace over
there to make sure. I make it a triangular part. A slightly bigger triangle than the
circle. Just to keep its axis symmetrical, the triangle should be equilateral, to keep
it balanced during the rotation. So this is equilateral and the median of triangle should
be at the center of the gears. How we find the median? We join the vertices of triangle
with the opposite line. Then the intersection of these two lines gives the center of the
triangle. I move this to this point. I shortened the triangle to this size. Make any fixed
dimension, let’s say 120 mm. I make circles in the triangle right here, let’s say, be
it be any dimension. Now I circular pattern this feature. Entities to pattern about the
origin, number 3. Done. Okay now, I extrude this triangle, say 5 mm. Done. Now since it
was created just over the plane, a mate has automatically been created. I just remove
that mate and make this triangle independent. Okay. Now, the center of this triangle, we
should have a hole there as well. Assign it a center. Done. Now we mate this circle here.
Keep it some distance with this. Let’s say the distance be 20 mm. Like so. Done. Alright
this should be connected to here. Fine. And these are linked with the shafts and through
bearings. I mean this gear is free to rotate about its pivot. Let’s say we have a shaft.
I slightly increase the size of this gear. Not the size of the gear basically, the nominal
shaft diameter be 10 mm. Done. Create a shaft right here, equal to this. I am just doing
to illustrate the basic mechanism, the epicyclic gear train follows. Okay. Now the bearings.
Ball bearings, radial ball bearings. One on each side. Okay. These bearings are present
here just to keep the motion of this gear independent of this shaft. This arm positions,
the center of this gear is not locked with the arm. This is pivoted to this shaft of
the arm, to keep it free about its own axis. So that it can work around the internal gear.
Okay. Do I have the necessary constraints? Yes. Okay. Now one more thing. Circular pattern
this feature around this three times and I will also slide this shaft. I just created
the end bearings as well. Slightly reduce the diameter of this to have these bearings
press fitted. Okay done. Okay now I have the necessary constraints. Now I have to introduce
the gear mates to make this mechanism work. Then I will show you. Okay this can rotate.
This is basically connected to, I will insert a new part here. Both directions. This is
the input shaft. And this is, I am inserting another part, this is the- here the output
is derived. That’s fine. Okay. Mates I defined at this shaft is locked to this gear. And
this shaft is locked to this carrier plate. This is called the carrier plate because this
carries the pinions around the sun. These are called planets. This is called sun. Okay,
I think to fail to create the mates. I again do the same. This is done. Lock. This is done.
Okay. Now when I rotate this shaft, the gear rotates. Mechanically, this shaft is locked
to this gear by keyway. Mechanical engineers should be familiar with the keyways. And this
shaft is bolted to this carrier plate, so these are also locked. Once I show you the
basic mechanism, we will go into the detail design as shown in the module; the target
module we want to create. Okay. Now, I
introduce the gear mates. I’ll go to mechanical mates gear mate. I will mate this gear
to this gear. Ratio I will adjust myself. It has 80 teeth and this one has 40 teeth.
Let’s see if it is working or not by rotating- yes. Yes these are working perfectly fine.
Okay, now I have to create the gear mate with ring gear. Mate Mechanical mates gear
mate, this gear with this gear. This is 40. This should be 160. We maintain these ratios
according to the pitch diameters. Okay let’s see how it goes. This happens when the outer
ring gear is free to rotate. The planet gears paddle at their position and this result into
the neutral gear and results no output motion. In our case, the ring gear is bolted to an
external case which is fixed, which means that we should fix the external gears. Now
I have put the fix constraint here on the internal gear. This “f” indicates the
fixed constraint. Now if I rotate this in any direction, the gears will start working
inside it. Like this. That explains the basic mechanism of epicyclic gear train. Now the
speed by which this shaft is rotating is higher than this. As the shaft rotates, this carrier
plate rotates, resulting in the rotation of this shaft and if you go in the motion study,
motion analysis will give, let’s say 10 RPM and simulate the motion. And we calculate
what is the motion output here. Displacement-velocity-acceleration, angular displacement- no, angular velocity,
magnitude, this face with respect to the fixed reference, we create the plot. The result
comes out between 20 and 20. It means that it is 20 degrees per second. It means, let’s
convert 20 degrees per second into revolutions per minute (20 degrees per second into revolutions
per minute), we divide 20 by 2 pi which is 6.28 and multiply by 60. Wait a second. I
must be doing something wrong here. Let me plot the two on the same graph. Displacement-velocity-acceleration,
angular velocity, magnitude, this shaft with respect to this and add to the existing plot.
The plot I already created. And now I see the results. Show plot. Okay. Now this scales
come for the one graph and this scales come for the other graph. The 20 degree per second
one is the output shaft as we measured earlier and 60 degree per second is the input shaft.
So we see a reduction of 1 ratio 3 from input to the output. So we have achieved the reduction
which results in increase of the torque at the output. Now, what is meant by stages?
This. Let’s see if I can copy the whole thing I make in this assembly. I randomly
save this. I just want to tell you what happens in the multiple stages. This is a just a single
stage epicyclic gear box. What happens in the multiple? I copy..make assembly from assembly.
I put this assembly here. I copy this assembly. Like so. Another copy. Okay. Now let’s assume
that this input is rigidly connected to this output, so the input of the next stage was
the output of previous stage. And it results in further reduction, for example, if we place
such similar 3 epicyclic trains in series, then how much would be the reduction? For
example, it was 3 ratio 1 in the first and in the second it is further divided by 3 and
in third it will be further divided by 3. It means we will achieve 1 by 27 reduction
in the speed and the torque will be multiplied by the 27. Okay this was the basic concept
of planetary gear train. Now, we will come towards our target model. We will exit this
as this was just for the explanation of the epicyclic gear train.
Now, we come towards the original assembly. The same is here just it looks complex just
because it has more perfect engineered geometry of every part, the proper bolts have been
shown here fixing the assembly to the case, bearings have been shown. Okay. Now, in order
to model this, we start from the input shaft. Okay, where is the input shaft? I just want
to start from the beginning. Planetary gear box. Okay, this is our planetary gear box.
This is the casing of the gear box. It has been divided into low speed and the high speed.
Low speed, in low speed section, there is the only one stage that is included and in
the next subsequent stages, the subsequent stages are included in the high speed. Low
speed, sorry. It starts from the high speed and goes to the low speed. As you can see
in the feature manager design tree, let me show you the feature manager design tree of
this assembly. They are mainly the nuts and bolts and the washers. Just look at the gear
box. Gear box low speed. Gear box high speed. This is the input side as at the start the
speed is high and it starts getting lower in each subsequent stage. This has the highest
speed and this has the lower speed. Then next has further lower speed and the output has
the lowest speed. Okay. This whole assembly is axis-symmetrical, so making the housing
is not a difficult task with this. Just copy the geometry of this. We just don’t need
to copy the geometry. We make its geometry according to the gear that is included. Now
to get the information about the gear, we have this gear here. Let’s design the high
speed gear box first. We go to new assembly. I exit what I opened previously. This assembly.
Now the new assembly interface, I will create the gears as in the..this assembly. Okay.
By clicking on the gear I get the information. This is from the metric with module 3, 120
teeth and 20 pressure angle, 10 face width. So this gear can be created easily. This is
the data I have with this gear and the one thing to be noted that the module thing, all
the gears that are mashing together should have the same module. Module dictates the
size of a teeth. If module is different, the gears will not be able to mesh together. Okay
this is the input shaft. We see the design details of the central gear. It has 80 teeth,
10 face width. It has 120 teeth, 80-120 , 80-120 and this pinion being the shortest has 20
teeth. Okay this is the kinematic design done for this first stage planetary system. And
this is the output shaft of this. Okay. Now, where to start? We start from making the first
stage planetary gear box. Let me go to this assembly. Okay in this assembly, I import
the gears as required. The sun gear. Sun gear, it had the module 3. Number of teeth being
60 and face width being 10. We will adjust nominal shaft diameter later and the keyway
configuration later. We also import the internal gear which had 20 teeth, 120 sorry. Number
of teeth are 120. And 120 into 3, 360. So the outside diameter should be greater than
360. We make it like 370. Or must be 400. It will look nicer. Okay. So we have the internal
gear as well. Now for the planets we have, we choose a 20, 20 teeth planet. It is here.
Okay. This should float. I might made a mistake. Selecting it having 60 teeth rather than 80,
it should have 80. 80 plus 20 plus 20 should be 120, equal to the size of external gear.
It should be 80 teeth. Done. Okay now the size is okay. The first stage gear box is
almost done. Join it. Okay. Next, we will see what is the. Okay. It has a keyway inside
and a hub extended on both sides. Let’s see what is nominal shaft diameter. It is
11.25 mm. it means it is 22.5 mm diameter and the hub diameter is 7.5. The face width
was as expected it is 10mm. So we have a 7.5 mm hub here. Add a toolbox component, we select
here, hub style- both sides. Okay. I do not remember the hub diameter that is also unimportant
as well as we do not go into those details as in that drawing. Okay. The nominal shaft
diameter is..okay we have a keyway also. Nominal shaft diameter is around 22 and keyway rectangular
one. That’s keyway. That keyway is used to lock the gear with the shaft and the shaft
comes inside it. Now this is done. I will see the details of other gear. This also has
hub on both sides. The hub diameter is approximately equal to the internal or we can say that dedendum
diameter of the gear, inside diameter or this is called inside diameter. This is called
the outside diameter and the line along which the gear is meshed and where lies here is
called the pitch diameter, the diameter that is formed around this circle. Okay. To see
the details it has – nominal shaft diameter is 37 mm and this is larger just because it
has to carry the bearings inside it. This is 42 mm. so we will edit our gear. We will
go into the assembly, edit our gear according to the requirement. The face width 10 is okay.
The hub style- both sides. Hub will be slightly shorter, it should be around 60, no 20. 20
is too less, I am just guessing. Okay 40 looks fine. 50 would be perfect. Oh yes. Nominal
shaft diameter is 37mm. The nearest one, I choose the nearest one. There is no option
to directly create the step inside this, there is no shaft keyways since it is not required
to be locked, it is on the bearing with the carrier plate that drives it, that carries
these pinions. Okay. The overall length should be 10 plus 7.5 plus 7.5, that should be 25.
Okay, I make it 25. Okay now that’s nice. I make this 25 as well. Okay. I am skipping
this step of creating another cut here to carry the bearings, these, the step is created
just because that bearings that are inserted will not slide in one direction. Just for
the exhilaratement of the bearings, I insert the bearing here. The size of the bearing
should be, I go towards the smallest sizes, that should be around 42, the diameter should
be slightly higher. Okay, there it is around some nice value. Thickness should be little
less than 17..17 sounds too much. Okay that’s fine. This is having lower thickness. Just
according to the availability of the bearings in the market that you can easily access you
should design the internal bore and the stepping of this gear, being a mechanical engineer.
Okay. Okay let’s assume it is okay. Just creating it from the very basic. Okay the
bearing comes here. In fact the bearing comes on the both sides in the actual assembly and
the carrier also comes on the both sides. Now we will continue by creating the carrier.
Let’s examine its geometry. It has a very simple geometry and this part can easily be
created by the milling process from 5 mm plates. Let’s see what is the thickness. It is 8mm.
we get the 8mm steel sheets are available in the market, steel or iron or whatever material
you want to use. These materials are available. You just either make them on CNC milling or
manual milling, there are many ways. For cnc, you have to generate the g-code for these
contours. And you can easily mill out this part. So this is not such a complex part from
even the perspective of 3D modeling not even from the manufacturing perspective. Okay.
Let’s examine its geometry. These circles are 272.4 mm radius and the center circle
is 72 mm, 72 – 272, okay that’s fine. I can easily create such part. Just the important
thing is the distance between this circle and this circle, the center of these circles
is 150. This is the basic kinematic design of this carrier plate. Okay. We go into new
part. First we make a circle, make it around 200. Okay this circle is here. Keeping the
size to be 272, 272 mm, and I think it should be, that was radius 272 mm, it should be more.
Anyways, let’s continue towards the design, it should be 272.4 into 2 – that’s how
it is. We make it circular sketch pattern. Entities to pattern is the circle - 3 times,
for better tuning, okay that’s fine. We have to create circles, trim the outside thingy,
make it farther, okay that’s fine. Just make it a distance from here be 320. Okay
that’s fine. Let’s trim unnecessary part of the circles, so here, Oh, I made a mistake,
here, this, this, this. Just at the center, I create a line from the origin to the center
point of this art and a circle on this. Fix this line and dimension of 150mm. okay it
was 150. Again made some mistake, it should not be fixed. I unfix this line. I increase
the distance. I should increase this, the radius of this, it should be 400. Okay. I
don’t think it’s 400, 380 may be. 350 might do the trick. Okay that’s fine. Make
it further away from this, 4 becomes too much. 350. Okay that is fine. Slightly increase
the size of the circle. Let’s make it 30 mm. Patinated around center point, this should
be 3 number. Okay done. The carrier plate is almost finished. The extrusion was 8. Just
adding fillet to make it look better. Let it be 5 mm or be 4 mm. okay that looks fine.
The center point…this was 72 mm as I don’t remember, 72, and for balls it should be something
like this. Okay this thing is done. We go into the main assembly- insert components.
I think I have not saved the part yet. I save it as part 6 and I am not naming the part
as it is not necessary at the moment. You can make the nomenclature at the end of the
project by modifying the names. At the moment of designing, you should only concentrate
on designing to make it perfect. Okay now, here comes our carrier plate- this, this,
this not being constrained as concentric, now it is. Okay. This is basically on the both sides of this, on this as well as
on this side, so we mirror the…mirror this part about this plane. Let’s see how it
goes, it goes excellent. Okay. Let’s see what we have to make. This 2 sided one intersection
view. The one side is connected to the shaft and the shaft decides the output. The ring
gear is bolted to the external housing. Okay. So we are almost done creating one of the
stages. The next stages are also created in the similar manner. We will create a shaft
and bolt it in this area and we will create another shaft and bolt it in this area. So
the mechanism will work, these planets need to be patterned around the center 3 times-that
is not a big headache, I must do it right now. Okay. Like this. Okay. Now one thing
that remains is the housing. Let’s make the housing. Let’s make the complete housing.
The housing of this is very simple and straightforward. I will tell you how. This is basically the
axis-symmetry housing with bolt holes being patterned around the circle. So, these, no
matter how much part this has, this can be created by just one revolve command. Just
one feature. The other feature is for the holes, for the bolts. Okay, now to create
this part of the housing, I’ll show you just. Let’s say sketch in this plane convert
into these, directly pick the profile from here. Also from inside, precisely from the
bearings. It is getting the points. Alright I managed to do, sectioning it- I create a
sketch here and box here, extrude it, cut it. Okay now I see this as, I can now easily
copy this profile convert these- click on this face- done. Just to correct it from here
a bit-like this- trim the wrong part out that is just been created due to bolts base. Okay.
I will copy this new part. I will revolve this around this point. Just should be a bad
sketch. Let’s see how much the distance is from the center. The central portion was
25mm, so it has 25 distance from the center and I create it as- exit this part. Make a
central line keeping it fixed at a distance of 12.5 mm. okay now we revolve around this
line. So one part is created. To create the holes for the bolts, we create a sketch here
on this plane- here. This can be circular pattern around this disc like this. We can
insert bolts all around this the way we want. Okay now since you know the way of creating
one of the piece of housing, you can create the all parts of the housing according to
your requirement. So I have demonstrated how to create each and every part in this. I do
not think anything remains in this. I have told you how to create the carrier plate,
how to create the housing, how to create the ring gear, how to do the kinematic design,
how to make the sun gear, how to make the pinions, how to create the animation. Now
I will use the readymade part to get this complete assembly again. The only thing I
left is the creation of this spline and this is not a big task- just a extruded cut from
this face. Spline can be easily created. And in this stage the gear is bolted to this assembly.
Okay. Now. I suppress this extrude cut. Now let’s start doing this assembly from the
parts. I will tell at the end how to put these bolts directly inside it. Okay. First let’s
do it without the bolts. We create the high speed gear box. I got new assembly. I will
show you how to assemble each and every part in one environment. Okay. We saved for- input
shaft-part-assembly, this assembly contains the gear as well. Okay I will just get the
input shaft. So we have the input shaft right here. I will close the unnecessary things.
Let’s see what this timken bearing, input shaft then, keystock. This key is used to
lock the shaft. Okay. This is inserted here in the keyway to show that here the key is
inserted in this, then gear is inserted on this keyway- it gets locked in the keyway-
like this and then bearing is inserted. Okay. I go back. Okay. I have defined how the input
shaft is assembled. So, in this assembly, I directly import the input shaft assembly-
complete assembly. Okay. Now just to tell you how to insert the Timken bearings. You
can get those bearings from the internet from the Timken website. The toolbox has SKF bearings,
Torrington inch, Torrington metric and ISO standard bearings, ANSI metric standard. So
you have a big choice for bearings. You can find any bearing from this choice and these
are readily available in the market. Okay. Let’s see which bearing is used in this.
This is… okay this is our input. These all are the Timken bearings. The use new environment,
I import the input shaft directly. Input shaft here… let’s say that we create a standard
axis that we will use in our animation later. We create an axis here. And we start from
right plane meeting this shaft here. Okay this is fixed. We make it float. Okay. Here
and get float. Okay. Right plane. This plane is here- axis, internal bear, axis here, so
this is constrained. Let’s test it. Okay, so here starts the input shaft. Let’s insert
the other parts. Let’s see what else is included in the low speed…high speed side.
Input shaft then stage one planet, okay fine. Stage one planet then high speed cover, high
speed case, okay. Let’s insert the high speed cover first. Just to know I need exactly
make it transparent, change transparency, just fit it over this. Okay. It comes right
here perfectly. Just let’s see how it is fitted there. We keep this view. The bearing
is aligned with this face and the second bearing with this step. So here is the key point.
This is the little output shaft, outside the shaft and this is connected to the planetary
carrier. I might have made other way round. This is the retaining ring. It is inserted
on to the groove of the shaft to retain the axial movement of the bearing. Okay just to
lie with this bearing, we select this face, then we select this face and this face. Along
with the assembly let’s just keep assigning the colors. Okay the next part is this – high
speed case. We align the holes, then make them concentric- this is aligned. Okay. Now
get the ring gear. Ring gear stage 1. Fine. Mate. Hide for moment just to mate this with
this, like this. Okay these are…okay aligning with the holes – done. You save it with
a new name. Okay. This is done. Let’s hide it for a moment. To add the planetary carrier-
this complete part should be added excluding the planetary carrier- excluding the ring
gear actually. So this was stage one. Stage 1- I add the stage one here directly just
to wrap it up. Insert components- stage 1 planet. Now, insert stage 1 and dissolve this
assembly to specify their appropriate mates. Okay. This should be fixed and this should
be rotatable. Okay we are going fine up till now. Okay. We have all the parts. This is
unimportant to add it second time. We assign them the proper mates – here, here, okay.
Delete these other parts as these will be patterned. Okay. Let’s consider that we
have done till this point. Let’s just assign the mates. This is fixed. This is fixed. This
should be rotatable. But…And… this should be at a fixed distance from this point and
this should be rotatable about this. This should be here. This should be locked with
this one. Now, let me correct it. Let us position it again; it will be placed near this point.
Alright, just wrap it up by assigning the appropriate mates to each part. We already
have a lot of time doing this tutorial and we need to end it in few next minutes. So,
I think everything has been explained you need to model this. Okay. First, I’ll fix
this, then I mate this shaft with here, from here to a distance. Let’s lock these bearings
with this. Okay this is already locked. Let’s see what is movable. Okay. The distance…now…this,
this should be locked with this, lock…okay this is a part of one assembly. We first need
to dissolve this. Okay let’s see what is not connected with this. The pinions should
be pulled outside and the rings should be pulled outside. Okay. Where is the ring gear?
Okay. Here is the ring gear. We pull it out of the assembly. We lock this ring gear to
this. Now, what remains? Okay, pinions are left. Twine its planets outside. Okay. So
we do not need these planets here. This I will delete and I pattern this planet around
this circle 3 times. Use the gear mate. Advanced mates. Mechanical mates. Gear… this is 20.
This is 80 teeth. This is 20. This is 120. Just forgotten the ratio to the teeth. Let’s
see if it is working okay. This seems quite fixed. Then put shaft. Okay. Gears are not
been yet retained axially. Okay we retain them by introducing this mate. This should
be
in plane with this. Okay. The gears are functioning as desired. Smiting is complete. Now, direct
for the stages we save this first. Minimize this. Open the main assembly. To make it function
properly, we should dissolve this, high speed – dissolve subassemblies. Let’s see if
it is still working as it is desired. Okay some mates might have been removed. Let’s
assemble the low side now. This, this and this should be fixed. Now we hide them, the
ring gears should also be fixed. Okay they are part of assemblies. Stage 3 and stage
4. We remove the ring gear from here. Remove the ring gears…ring gear… ring gear from
here and from here as well. That’s fixed- these 3. I can fix them. Alright stage 3 – now
what else needs to come out of stage 3… the pinions…okay let’s start from stage
2. Let’s have a mate…this…distance, then concentric mate so it stays in place.
Then I remove this gear out of this. Okay this is fixed. Okay this now also fixed. Okay,
for this one, remove these 3 out of this, replace the mate here- distance mate and the
concentric mate should be…concentric mate…and when this rotates, this. This with this. And
this with…okay this is already constrained. Now we go towards stage 4. The distance of
this should be…like so… this should be concentric with this and this should be moved
out. We are moving these planets out of the assembly because they need to spin independently
of the carrier plate. We also might left some of them inside…this one is okay. Okay this
one is still inside, move it out. And in this assembly, this is fine, okay they are also
not independent. So I make them, place the concentric mate first then the face mate for
this. Okay. This should also be moved outside. And, place the mates here. I might have done
some mistake with this part. ST3 minus shaft. This will go inside this assembly. Okay. Okay
I messed with this plane…and this is also been corrected. I place the mate here. This
is okay now. Plate this mate here. This is also okay. This goes. Okay. There is also
a problem here. Okay this come out to this and this should be fine now. This should be
concentric with this. And this co-planar with this. Okay. This stage is now okay. Last stage
remains… okay…so almost everything is done. Okay this is creating some problem here.
It should be…these pins should be separated from this. Parallel pin hardened. I would
rather consider deleting them. These are no use at the moment. Okay now everything has
been done. Let’s specify the gear mates to make this assembly work. Okay. Let’s
do the remaining 5 to 10 minutes work and this will be then finished almost. Okay. This
will be the mechanical mates, gear mates and we are looking 30 teeth and 80 teeth. 30 and
80. Let’s say the direction is right or we have to alter it. No, the direction is
not right. We go to the mate and reverse it. Okay
it should be fine now. Okay. Now it is behaving as we want. Okay we have to do the same with
the others. Okay now this carrier is input to the next sun gear. I want to see the sun
gear. I hide this temporarily. Okay here is
the sun gear. If I rotate this, okay, this is fine. Let’s mate this with this one.
Mechanical mate gear mate and let’s see what is the ratio? It is 20 teeth and
20 teeth. Okay both are 20 teeth. Let’s make it 1 ratio 1. Okay let’s see it has
got right or not. Okay it is perfectly fine and the external- it should be again a gear
mate, 20 teeth with, we have to see, 20 teeth with 60 teeth. 20 with 60. Let’s see if
it is fulfilling the purpose. No… it is opposite. We go here and check the reverse.
Tick. Okay. Its fine but there is a slight misalignment, we delete it for a while, move
it slightly here, choose this face, Mechanical mate gear mate. This 20 teeth, this 60
teeth. Just one last mate, these are 60 teeth and 20 and 60 combination. 20 and 60. Let’s
see if it is working okay. Now, its direction should be reversed. Okay we go here and reverse
direction of mate. Okay now it is working fine. Just one more thing. We hide this as
well. One last gear mate with this as I remember, okay, I have to gear this one with this. This
is my last thing that I have to do. I think this is 20 teeth 20 teeth means 1 ratio 1.
Let’s see if got it right. Oh my god. This should be fixed with that. Okay let’s see
the row mechanism. This is working around this nicely. This is working fine. Okay. This
is not..the third stage not connected to the fourth stage. Okay we had this as well. Okay
so the problem is this gear. We mate this with this face, this plane concentric with
this and now the one last mate the gear mate. Mechanical gear. This is the 20 teeth
versus 20 teeth means 1 ratio 1. Okay this is now working fine. We have done. Almost
done. Let’s see if it starts from here. It works okay. One last thing, mate lock
this gear with this must be. Okay now this should be connected. Okay it is taking time
to calculate. Okay. Now the whole assemble is almost linked and the mates are working
perfectly fine. Okay we can see the output shaft is also rotating. Okay now, the one
final step is to dissolve this assembly here. First we unhide the hidden parts, show. Show
it too. And the casing is yet to be shown, show this one as well. Okay is it working?
Yes. Working very nicely. Okay we are dissolving this assembly now. A big step. Okay. Does
this work? Here Instead of doing a lot of work again, reopen the same assembly that
we were able to achieve the correct mate with okay. We insert the high-speed gear box directly
here. Mate it here. Now, we will dissolve this part. Dissolve this assembly. Okay. Now
this should be connected to the one- the gear that works. This should be connected to this
one. Mechanical mates gear mates. Are they equal? 20 teeth, 30 teeth. Okay. 30 teeth.
20. Let’s see we got it right or wrong. Okay this is fine. The only thing that is
not rotating is linked with the gear now and it is taking time for calculations. That is
when I rotate this, this rotates. Okay. Now what will cause it to rotate will be the,
okay we have already gear mate here. That is fine. Just the last mate here. It should
it does not allow me. Okay no problem. Something must be…yeah this is fixed. I make it float
and make it move…I am not concerned with the bolts here. Just want to show you the
results of this assembly. Okay. This must go here. Okay this is fine. Okay this is fine
as well. Okay. Just we need to fix this final part now and the whole assembly is going to
work. This is not important. I delete them all. Okay let’s see how it goes. Okay. Let’s
do the motion study. Make it 12 seconds. Place the rotary motor here. Must be at 50 RPM.
It must be motion simulation. Make it like here. Rotary motor. Let’s see how it performs.
Oh, this is working very nicely. The output shaft is rotating as well. So you can see
the high level of reduction this planetary system can achieve within such a small space.
The output is almost rotating at negligible speed as compared to the input shaft. This
is such an example of high level of reduction within such a compact size. So these were
our results. Let’s increase the speed of motor or run it at higher speed, let’s say
5x. So, we can observe some movement. Look at that. So these are our results. Just we
compare- displacement, angular velocity, magnitude of this. Okay. Plot it. Now, this is a plot
1. And the results of output shaft - displacement, angular velocity, magnitude, add to existing
plot- plot 1- done. Let’s see the plot results. This is tremendously…this is…one is between 1 and 2, it means it is
1.5 and the other is 300…between 300, so we have achieved a tremendous reduction around
250 to 300 times lower. So that was our achievement today.
Thank you for learning. Thank you for following my tutorials. Goodbye.