# Questions tagged [power-transmission]

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### Transmitting power over long distances what is better AC or DC?

I found this answer to a related question. The part of the answer that's confusing me is: Transmitting DC power over a long distance is inefficient. Thus AC supply is a far more efficient to ...
375 views

### How to connect a motor shaft to a plate

I'm trying to drive an aluminium plate using a motor via a 20mm-wide 2mm-thick stainless steel tube. The tube is driven by a 6mm motor shaft via a pulley and the torque will be around 5Nm at most. Is ...
573 views

### What's the history of the 345 kV voltage level in power transmission?

I'm interested in the history of the 345 kV power level for high voltage transmission in the United States. I've got two (and a half) questions: According to this source 345 kV was first applied in ...
323 views

### Why are both conductors in a High Voltage Direct Curent powerline isolated from ground?

Picture of a High Voltage Direct Curent powerline (HVDC line) on the Læsø Island, Denmark (from Google Street View): We can observe that there are 2 conductor cables, and that both are insulated from ...
281 views

### Torque and RPM calc

started by designing the gear meshing, and now I need to calculate some parameters to determinate if this meshing works for me. The system considers an electric motor, which technical parameters are: ...
171 views

### How does power generation (hydro, wind etc…) account for variable power consumption?

I know in a power distribution system, the power is generated (from a dam or turbine or something) and consumed immediately. But the power consumed is variable. So how does the generation system take ...
150 views

### Why in the construction of power transmission towers , the rods are hinged oblique? [closed]

I know if a rod is hinged at its two ends and if there is no load act upon it along its length then the forces exist only along its length but i don't see how this characteristic comes into play ?
426 views

### Right angle gearbox, proper name or design

I'm looking for right angle gearbox, but everything is horrible expensive or in parts like two bevel gears from aliexpress. Where I can find or how to name transmission like this in the picture but in ...
125 views

### Wind turbines with down tower power units. Why aren't they more common?

Concerning the big megawatt wind turbines, if there is such a big trouble with gearbox bearings failing much earlier than expected and costly maintanence or replacement of huge gearboxes, what is ...
53 views

### Gear Ratio of a Stepped Planetary Gearset

I was looking into planetary gearsets, and came upon the concept of a stepped planetary gearset. In the image shown above, if my input was the blue sun gear, the output was the planet gear, and the ...
64 views

### How much aluminum does a HV, MV or LV transmission line use?

I have accurate statistics about the total length of high-voltage (110-400 kV), medium-voltage (1-70 kV) and low-voltage (0-1 kV) transmission lines in my country, and they are: High-voltage: 22 500 ...
229 views

### Find clutch for parallel hybrid sailboat

I am replacing my dead diesel engine in my sailboat. I wish to replace it with a new diesel and an electric motor in parallel hybrid. Hybrid vehicle drivetrain This would allow me to: Run the ...
37 views

### Optimum spoke shape for wheels made of solid material

Currently I am designing a bicycle sprocket to be laser-cut out of 3mm steel. Steel is heavy, so I want to make some lightening cut-outs, and I want to optimize the shape of the cutouts. I will ...
25 views

### I'm looking for the simplest way to increase rotational speed from 120 to 5,000 rpm for a light duty device

I'm currently designing a device and want to increase speed from 120 to 5,000 rpm. Device is lightweight, hand operated, free spinning, low torque in/out. Picture a cheap fertilizer spreader from Home ...
33 views

### Exceed 'designed' speed ratio of timing belt

I'm trying to create a setup to transfer motion from a motor to a shaft that requires a much higher torque (bi-directional). The housing is about 6 inches long and the speed ratio needed will be ...
129 views

### How do I calculate the velocity of the piston?

I have a system with a motor connected to the trapezoidal lead screw. The lead screw is connected to the tube which is connected to the piston. The piston has to pump 1000cc oil against a pressure of ...
109 views

### Attaching Gear onto Motor

I want to attach a 12 toothed spur gear with a bore diameter of 6mm onto the shaft of this motor (6mm diameter). How would I go about doing this? From what I see, the shaft is smooth so is my only ...
83 views

### Why do trains use the same wheels for staying on track and propulsion?

Trains where originally designed to keep the train on track. At the time trains where pulled by horses and used to transport coal (and such) out of mines. The two functions have very different ...
25 views

### Delivering RPM from a fixed wheel to a moving wheel

I have spent the past few days thinking about a good way to get power/RPM from a fixed wheel delivered to a wheel that is able to move in a 2D plane relative to the fixed wheel. I am not too good at ...
71 views

### Key fitting - Shafts and Gears

I am designing a gearbox and wanted to know whether the key on the shaft and gear must fit exactly with the bore in the gear and keyway in the shaft. Ex. If there is a key that is 3x3 mm, and does the ...
44 views

### What is name of clutch system in a roller shade?

I am trying to figure out what the exact term is for the clutch system used in a roll-up window shade. I thought they were called centrifical clutches, but that typically gives me the opposite ...