Analysis of motor cooling system in Hengli Motor's dry goods sharing

Today, Hengli Motor will give you a brief understanding of the motor ventilation and cooling system.

Hengli Motor Structure and Cooling Method

The so-called primary cooling medium is the cooling medium that first receives heat from the effective part of the motor, while the secondary cooling medium is a cooling medium with a lower temperature than the primary cooling medium, which takes away the heat of the primary cooling medium through a cooler.

The structure and protection type of the motor are closely related to its cooling system. Therefore, we will discuss the selection of ventilation systems and the corresponding overall structural design issues from this perspective. Overall, the circulation methods of cooling media can be divided into open circuit cooling and closed-loop circulation cooling.

The cooling medium for open circuit cooling is taken from the surroundings of the motor and returns to the surroundings after passing through the motor. Small and medium-sized motors generally use this cooling system. The primary cooling medium for closed-loop cooling passes through the motor and, if necessary, through a cooler to form a closed-loop system. Heat is transferred from the primary cooling medium to the secondary cooling medium through components or coolers. Large motors or motors with extremely harsh operating environments often use this cooling system.

Hengli motor with different cooling cycles and installation methods

Using different cooling media for cooling methods, there are corresponding changes in the structural type of the motor casing, mainly in the arrangement of the inlet and outlet pipes (holes) of the cooling medium, the type and installation location of the cooler, and so on. Below are several ways to install the cooling medium circulation circuit.

The free circulation method allows the cooling medium to flow freely into the motor from the surroundings or over the surface of the motor, and return freely, such as in general open and protected motors.

The cooling medium is circulated through the inlet pipe or inlet duct from sources other than the surrounding medium of the motor, flowing into the motor through the inlet pipe or duct, and then freely flowing into the surrounding environment. This type of motor is used in environments with high levels of dust. Its air inlet duct introduces cleaner air from the outside to prevent excessive dust accumulation inside the motor, which can affect its electrical performance and cooling effect.

The circulating cooling medium in the outlet pipe or outlet duct flows freely into the motor from the surroundings, and then is sent to a place far away from the motor through the outlet pipe or duct, mainly to avoid the air heated by the motor affecting the working environment.

The casing of the motor with inlet and outlet pipes or holes for circulation is required to be closed except for the inlet and outlet pipe holes.

The primary cooling medium on the surface of the casing circulates in a closed loop and transfers heat to the surrounding medium through the surface of the casing. For low-power motors, the surface of the casing can be smooth. For small and medium-sized motors, in order to increase the heat dissipation surface and enhance the cooling effect, heat dissipation ribs are usually added to the base and even on the end cover. The protection type is generally IP44 or above.

The primary cooling medium of the built-in (pipeline) cooler passes through the cooler installed in the casing inside the motor, usually a cooling pipe integrated with the motor, forming a closed loop. The heat is transferred to the secondary cooling medium through the cooling pipe, which is the ambient medium around the motor - air. In China, this cooling system and structural type have been used in medium-sized induction motors with a protection level of 1P44.

The cooler installed on the motor is mostly used for box type motors. There are many types of coolers that can be installed outdoors and become climate protection type (IPW) motors.

Install a cooler inside the motor that does not require cooling from the surrounding environment.

A cooler installed on the motor that does not require cooling from the surrounding environment.

● Independently installed cooler. The primary cooling medium circulates in a closed loop and transfers heat to the secondary cooling medium through an independently installed cooler. Large motors, such as large hydro generators, use this cooling system. The coolers are symmetrically distributed in the machine pit, with cooling water as the secondary cooling medium.