Speed copy reductor

VR 1.0 BIS

Intro

Case study

TASK : We should build mechanisam that will rotate (at ending shaft) same angular speed as an large (driven) gear. Parameters : Drive gear : z = 21 Driven gerar z = 160 The rotary bar is a device similar to a huge funnel that receives coal from a surface mine and distributes it in 3 large bunkers. It is powered by a gear motor connected to a small 21-tooth gear. It is coupled with a large gear that is rigidly connected to the reverse rod. The large gear has 160 teeth. Lights

Situation and mounting place

solution

It is necessary to set the encoder that will get the angular velocity of the large gear, ie the rotating rod. Due to the required precision of angular velocity, I opted for a gearbox with cylindrical gears, This reducer does not transmit any load but only regulates the angular velocity of the large gear.
and that's why I called him speed copy reductor

Solution details

The transfer rate is f1
Parameters : Z2 = 160 - number of teadh on the large gear Z1 = 21 - number of teadh on the small gear Since the upper fraction cannot be shortened - it is impossible to make a model of coupled gears. If I should use straps or sprockets, it could slip and thus lead to an inaccurate angular velocity of the large gear.

With a little help by mathematic ...

If we look carefully, we should notice that the numbers 160 and 21 are divisible. Number 160 with 2.4.5.10.20.40.80 while the number 21 is divisible by 7 and 3. It follows that the transmission relationship can be pushed as well: f1 Now, We already have a sketch of two pairs of coupled gears, it is necessary to expand the fractions of the gear ratio so that the number of teeth is greater than the minimum. so :
f2
it is the number of teeth of the first pair of gears
for the other pair of gears followed by the number of teeth f1
Next step -

  designing the gear parameters 
Gear Number of teath module note
1 48 4
2 21 4
3 50 4
4 15 4
5 21 16 Entering gear
Gear 5 is the input and it is, ie its parameters are a copy of the drive gear (module and number of teeth). Lights

Kinematic scheme of speed reducer: gear arrangement

Gear no 5 is the input and it is, ie its parameters are a copy of the drive gear (module and number of teeth).

Gear calculation

SThe next logical step is to calculate the gears. First, I determine the module taking into account the dimensions, and then the calculation of the gears follows. A handy free gear calculator is here and I used it for the calculation. After the calculation of the gears, the calculation of the shaft, bearings and the construction of the shaft and the bearing housing follows. I chose a wedge connection on all gears.

Making gearbox

After the construction and preparation of technical documentation, the entire project was handed by the company "Elmont", which made all the elements except the formwork and the base.

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Gear

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Gear

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Shaft

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Housing

and all together Lights

circuit drawing of the speed reducer

Speed ​reducer maked and assembled
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Side view

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Front view

Making formworks and the base

The base and the formwork have a role (apart from carrying and protecting the gear elements),to adjust, fit and accutity adjusting the teeth coupling. Lights

Construction of the side formwork consisting of a cover sheet and a U-profile with grooves that also serve as sliders for moving the gearbox in the active direction

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The green plate serves as the encoder carrier, the output shaft of the reducer is visible

The top picture of the plates is a stand that is used to adjust the outside gears alligment . The central screw is used for rotating the gearbox, and the back side have circular slot for fixing the rear part of the gearbox in order to avoid its vibrations. Lights

The top picture of the plates is a stand that is used to adjust the outside gear of the input gear with a gear at the plant. The central screw is used to turn the gearbox, on the back side there will be an average circular one a slot for fixing the rear part of the gearbox in order to avoid its vibrations.

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Finaly appearance of the reducer and encoder assembly on the stand.

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Another view of the mounted reducer and encoder on the stand

Mounting

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The strand wellding

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Teath alligment control

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Top view

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Bottom view

 pvc:  127