Oil-cooled motor for compressor and variable frequency oil-injection screw air compressor employing same

Abstract

An oil-cooled motor for a compressor comprises a motor housing, a front end cover arranged at the front end of the motor housing, and a rear end cover arranged at the rear end of the motor housing. The oil-cooled motor is characterized in that an oil inlet is formed on the front end cover and an oil outlet is formed on the rear end cover; the motor housing is further surrounded by a shell; a jacket layer is formed between the motor housing and the shell; and the oil inlet and the oil outlet both are communicated with the jacket layer. The invention also provides a variable frequency oil-injection screw air compressor employing the motor, which is characterized in that the motor is connected in series in an air compressor system; therefore, noise can be reduced, heat dissipation is improved, the formation of condensed water from lubricating oil due to a low temperature is prevented, the cooling efficiency is improved, and the oil circulating cooling efficiency is thoroughly utilized.

Description

technical field [0001] The invention relates to a motor for a compressor and a variable frequency oil injection screw air compressor equipped with the motor. Background technique [0002] The drive motors of the existing general frequency conversion oil injection screw air compressors are mostly ordinary motors, and their basic structure is as follows: figure 1 As shown: the power line is connected to the junction box 3-3 and guided into the stator 4-4. Under the action of the magnetic field, the rotor 2-2 rotates and drives the air compressor through the drive shaft 1-1. During the excitation process of the motor, it will produce Excess heat, under the action of the fan 6-6 (rotating speed and transmission shaft synchronization) at the rear end of the transmission shaft and the air duct formed by the wind guide cover 7-7, the heat is discharged in time through the motor fins 5-5. If the speed of the transmission shaft decreases, the cooling air volume will also decrease be...

AI Technical Summary

Problems solved by technology

The so-called frequency conversion motor is to install a fan unit independently in the rear end windshield of the ordinary motor, and the fan speed remains unchanged. Although this solves the problem of poor low-speed characteristics of the motor, it improves the low-speed performance of the motor. The noise under the environment increases the axial length of the motor, increases power consumption, and increases the failure rate and cost

Therefore, the drive motors of variable frequency screw air compressors currently designed in the compressor industry are mostly ordinary motors, so the technical weaknesses of variable frequency screw air compressors are as follows: 1. The low-speed characteristics of the unit are poor

Because the heat dissipation of the motor is not good at low frequency, it is easy to cause the motor to overheat and fail, so the low-speed frequency conversion can only be maintained at about 40% of the reference frequency; 2. The air-cooled motor is affected by the air flow disturbance, and the noise is relatively large , especially in the high frequency range

3. When the variable frequency screw air compressor is running at low speed, when the ambient temperature is low, the circulating oil will appear low temperature as soon as it passes through the cooler, which will easily produce condensed water, which will have a negative impact on the host and the system

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