vertical motor

[nayka]

please ,can anyone tell me why in some drives ,we can find vertical motor instead a horizontal one although the horizontal one is more available(technicaly), and efficient.
many thanks in advance

 

[electricpete]

I think a horizontal will usually be preferred from a standpoint of cost and ease of maintenance.

But sometimes the mechanical load works better in a vertical position. One thought is vertical pumps. The lower the pump, the more suction head is available. So you put the pump as low as possible but often it is not convenient or possible to put the motor as low. Some types of deep draft pumps even have the pump far below ground. Having the motor on top of ground makes replacement much easier.

 

[vanstoja]

In shipboard powerplants, where space is at a premium, vertical pumps and motors are often specified for deck-space saving. Compact inline pumps in piping systems generally need vertically mounted motor drives. If mechanical shock is a design requirement (eg., combat ships) vertical pumpmotors are generally easier to shock harden than are spread-out horizontal pumps and motors.

 

[jbartos]

Suggestion: Also, motor operated valves tend to have vertically mounted motors. Check nuclear power plants. They used to have tours open to the public during the weekends.

 

[UKpete]

Another common application where vertically mounted motors are found is in cooling fans, e.g. in a locomotive where they blow out through roof vents. Unfortunately, this means that the motor axial-thrust bearings have to cope with both the weight of the fan and the rotor, and the thrust load of the fan.

 

[automatic2]

Im not sure that a horizontal motor geared to vertical is more efficient than a vertical mounted motor. You'll find many vertical mounts in water lifting applications. This is an increase in overall effeciencies. Many manufacturers offer a vertical configuration of thier more popular motors.

 

[acmotorengineer]

to nayka: your question is very general so limiting the discussion to a vertical Flanged motor with or without feet, there are three commom types of vertical, AC induction motors:

1. Normal Thrust. These motors are essentially horizontal motors with flanges ( usually without feet). The commom industrial flanges in the USA are P, C, D flanges. C&D are usually for machines and fans and P is for pumps. The rest of the world uses metric or DIN flanges.

The efficiency of these motors are the same as horizontal. They are flange mounted, vertical or horizontal, for convenience - usually lower cost.

Note: P-flanges are almost always vertical, D-flanges are usually horizontal and C-flanges, whatever. Larger P-flange motors cannot be mounted horizontally without additional frame support.

2. Medium (In-Line) Thrust. These motors are usually used for in-line liquid transfer. The flange mounted pumps are in-line or part of the piping system. The larger thrust bearings make the motors have lower efficiency - all else equal. The frame has a LP or HP suffix, i.e 365LP.

3. High Thrust. This is the vertical, hollowshaft motor designed for deep well, turbine pumps. These motors have bearings suitable to handle pump thrust and the weight of the pump and deep well shafting. Axial thrust can be up to 100,000 pounds. These bearings have very high losses and the motor efficiency is lower than standard horizontal motor. The actual motor efficiency, sans bearings, is the same as a horizontal motor, however.

Originally, vertical pumps were driven with a horizontal motor with a 1/4 turn belt, which you can imagine was a high maintenance installation. The VHS motor was developed to provide a more robust and reliable installation. At the same time the pump thrust bearing was taken from the pump and put on top of the motor to allow easy replacement without having to pull the pump - a very expensive proposition. This was done by having the pump headshaft come through the motor shaft (i.e. hollowshaft) and couple at the top of the motor.

This motor is common in the USA. In the rest of the world the normal thrust motor is used and the thrust bearing is still in the pump.

 

[nayka]

thanks for all for those detailed information;i can point to two response :-the first from electrecepete that:sometimes the mechanical load works better in a vertical position
-the secondfrom vanstoja that:If mechanical shock is a design requirement (eg., combat ships) vertical pumpmotors are generally easier to shock harden than are spread-out horizontal pumps and motors.
may be i need more explication to understand these points of view .
Although i agree with the remarque that have done actomoengeneer : my question was very general ;so i would explain the thing more:in lifts(in books) is cmmonly that we use a horisontal motor,but i found in a real lift(12 floors)that the motor is vertical ..my thought was that this position will reduice the inetia of system that affect the direct start of motor or the effect of the mechanical load that is high at the first floor.but i can't proove anything.
so would any one explain me the phenomena exactly .
many thanks.

 

[nayka]

it is not understood why :some times the load work better with the vertical motor;is the vertical position of motor does its inetia low!,
thank you in advance.

 

[jbartos]

Suggestion: The horizontal position loads motor bearings about evenly. The vertical position is heavily loading one bearing that carries the motor and potentially the motor load weight.