Muffler for hermetic compressor
DESCRIPTION OF THE INVENTION 
     The present invention relates to a muffler for a hermetically sealed compressor unit and more precisely to a muffler placed on the suction part of the compressor unit. 
     In the suction system of a hermetically sealed compressor, where the shell is at the suction pressure, there must be a separation of the coming-back oil from the sucked refrigerant and the discharge of this oil into the shell, the maintenance of the shell at the suction pressure, the lowest possible overheating of the gas from the entrance into the shell to the entrance into the compressor, the lowest possible load losses of the gas from the entrance into the shell to the entrance into the compressor and the lowest transmission of the pulsations to the gas inside the shell in order to reduce the noise. 
     It is the purpose of the present invention to provide the above-mentioned effects. The technical problem to be solved was the realization of placing the muffler on the suction part while separating the oil from the refrigerant gas and, at the same time, lowering the transmission of pulsations and lowering the load losses. 
     The solution of the technical problem is brought about by forming the muffler in two portions, the first portion being variously shaped, to attenuate the pulsations and separate the oil from the refrigerant gas, and the second portion to damp the gas pulsations with first means being provided in the second portion for damping and second means for discharging the oil from the first or second portion. 
    
    
     Further characteristics and advantages will become more readily apparent from the following description and from the enclosed drawing in which the figure illustrates a vertical section of a hermetically sealed compressor unit to which the muffler of the present invention is applied. 
    
    
     With reference to the figure a hermetic compressor unit 10 is formed by a shell 11, an electric motor 12 mounted in a known way on the body 13 of the compressor for driving the vertical shaft 14. The relationship between the motor 12, body 13 and shaft 14 are not described as they are known in the art and do not form the object of the present invention. A little tube 15 fixed to the shell 11 conveys the refrigerant gas from the vaporizer (not illustrated in the drawings) to shell 11. The little tube 15 is in axial alignment with a bore 16 on muffler 18 placed inside the shell 11, and it is linked by a flexible connection 17 to muffler 18. 
     The muffler 18 is formed by a first portion indicated by 19, variously shaped, which permits the attenuation of the pulsations and the separation of the oil from the refrigerant gas and by a second portion indicated by 20, filled with porous material 21 which, by forming cavities, permits a damping of the gas pulsations transmitted outwardly and, at the same time, the discharge of the separated oil through a little tube 22. 
     The refrigerant gas without oil, from the first portion 19 passes into the head 23 of the compressor through the pipe 24. 
     The muffler damps the refrigerant gas pulsations. As many hermetically sealed compressor are mounted on springs, according to whether the muffler is placed solidly with the shell or with the compressor, the other section will be obviously flexibly connected.