FR2844313A1 - Hermetic scroll-type compressor comprises shield surface integrally formed on crankcase, where oil and gas mixture impinges upon shield surface, where oil separates from mixture - Google Patents

Abstract

A hermetic scroll-type compressor comprises a shield surface integrally formed on a crankcase (32), where an oil and gas mixture impinges upon the shield surface, where oil separates from the mixture. A hermetic scroll-type compressor comprises a motor (20) mounted in a housing; a compression mechanism (22) mounted in the housing, operatively coupled to the motor; a crankcase in which the compression mechanism is secured; a shield surface integrally formed on the crankcase; and a suction tube having an outlet end mounted in the housing, at least a portion of the shield surface being aligned with the outlet end. An oil and refrigerant gas mixture enters the housing via the suction tube, the oil and gas mixture impinging upon the shield surface, where oil separates from the mixture. An Independent claim is also included for separating an oil and refrigerant gas mixture entering a hermetic compressor, comprising drawing refrigerant gas entrained with oil into the compressor through a suction gas tube mounted in the housing; and directing the refrigerant gas entrained with oil into contact with a shield surface integrally formed with the crankcase, the oil clinging to the shield surface, and the refrigerant being directed over the motor mounted in the compressor housing and into the compression mechanism.

Description

Field of the invention

  The present invention relates to orbital spiro compressors and more particularly to an oil screen for directing and separating the oil from the fluid under suction pressure entering the compressor.

State of the art

  In general, a spiro-orbital compressor comprises a compressor housing with a suction gas tube whose outlet end is in the housing. The suction pressure fluid arriving in the compressor is a mixture of oil and refrigerant which passes through the outlet end of the suction gas tube to arrive in the compressor housing. The suction gas tube is usually spaced from the suction inlet of the compression mechanism to prevent a large amount of oil entrained by the inlet coolant from entering the compression mechanism.

  In some compressors, the oil and refrigerant mixture is distributed in the housing if it is not directed to a special part of the compressor when it arrives in the compressor housing. The oil and refrigerant mixture then comes into contact with the various components of the compressor placed in the bearing, the counterweight and the motor.

  A difficulty linked to the dispersion of the mixture of oil and refrigerant arriving in the compressor housing is that the fluid passing over the engine risks cooling it insufficiently. Furthermore, part of the oil entrained by the refrigerant must be separated therefrom.

  to prevent a large amount of oil from entering the compression mechanism with the refrigerant gas at the suction pressure.

  The entrained oil clings to the compressor elements when the oil comes into contact with them and the oil eventually drips into the oil tank at the bottom of the housing. However, the rotation of the crankshaft, the counterweight and the engine means that the oil arriving on these elements is projected towards the interior of the compressor housing. This delays the recovery of the oil as much as it takes a while to

  the oil to regroup and flow into the oil tank.

  Usually an oil screen panel is installed inside the compressor housing located essentially above the suction gas tube. An example of an oil screen panel is given in document US 5,055,010 LOGAN. The screen is fixed to the interior surface of the housing, for example by sprayed welding. When the refrigerant mixture and the oil enter the compressor housing, this mixture comes into contact with the oil screen. The oil in the mixture clings to the screen and collects on it. Then the oil thus collected descends into the oil tank of the compressor housing. A large part of the refrigerant then practically without entraining

  oil arrives in the suction inlet of the compression mechanism.

  A weaker part of the refrigerant is directed downwards over the

engine to cool it.

  A difficulty of the screens of oils used until now S5 is to be a separate component from the compressor which increases the cost of the compressor. In addition the cost of the whole increases since

  the oil shield must be attached to the interior surface of the housing.

  OBJECT OF THE INVENTION The aim of the present invention is to develop a more efficient oil screen for directing the fluid under suction pressure,

  entering and separating the oil from the fluid.

  Disclosure of the Invention The present invention relates to a hermetic spiroorbital compressor having an oil screen surface integral with the crankshaft bearing of the compressor. The oil screen surface is placed above the outlet of the suction gas tube installed in the housing and opening into it. A mixture of oil and refrigerant gas at suction pressure enters the compressor housing through the suction gas tube and comes into contact with the oil screen surface. A significant part of the oil in the mixture clings to the surface forming an oil screen and separates from the gas. The oil that collects on the surface of the oil screen drips into the oil tank formed in the lower part of the compressor housing. Part of the refrigerant separated from the oil is directed by 1 1-

  the surface forming an oil screen at the inlet of the compression mechanism and over the engine to cool the engine.

  The present invention relates to a hermetic compressor with a housing housing a motor and a compression mechanism. The motor and the compression mechanism cooperate. The compression mechanism is attached to a crankshaft bearing having a screen surface integral with it. A suction tube has an outlet end in the housing with at least a portion of the screen surface substantially aligned with the outlet end. A mixture of oil and refrigerant gas enters the housing through the suction tube and meets the screen surface so that

the oil separates from the mixture.

  The present invention also relates to a hermetic compressor with a housing housing a motor and a compression mechanism. The motor and the compression mechanism cooperate. A

  crankshaft bearing is mounted in the housing between the compression mechanism and the engine. A screen surface is integral with the crankshaft bearing and the oil and refrigerant mixture introduced into the housing meets the screen surface so that the oil separates from the mixture.

  The present invention also relates to a method for separating a mixture of oil and refrigerant gas arriving in a hermetic compressor and having a housing housing a motor. A crankshaft bearing is mounted above the engine and a compression mechanism cooperates with the engine. The process involves vacuuming the

  refrigerant gas entrained with the oil in the compressor through a suction gas tube installed in the housing and directing the refrigerant gas entrained with the oil in contact with the screen surface, this surface being integral with the bearing crankshaft and the oil clinging to the screen surface and to the coolant to be directed to the engine installed in the compressor housing and the compression mechanism.

  One of the advantages of the invention is that the oil screen surface forms an integral part of the crankshaft bearing, which reduces the number of components of the compressor.

  Another advantage of the invention is that the assembly step by welding the screen to the interior surface of the housing

  compressor is removed which reduces the mounting cost.

  Drawings The present invention will be described below in more detail with the aid of exemplary embodiments represented in the attached drawings in which:

  - Figure 1 is a sectional view of a compressor according to the invention.

  - Figure 2 is a perspective view of a bearing of the compressor of Figure 1, - Figure 3 is a plan view of the crankshaft bearing of Figure 2

  mounted in the compressor housing.

  In the description of the drawings, the same references will be used to designate the same parts in the different views. Although the drawings represent an embodiment of the invention,

  these are not necessarily to scale and certain characteristics are represented in an exaggerated way to better present and

explain the invention.

  Detailed description of the invention

  According to Figure 1, a hermetic spiro-orbital compressor 10 comprises a housing 12 formed of a main casing 14, an upper cover 16, a lower cover 17 and a base 18. The cover 16 is welded to line 15 at the upper end of the main casing 14 and at the separator plate 21. The base 25 18 has an annular support 19 for receiving the compressor 10 in an essentially vertical orientation. The base 18 is welded at 15 to the lower end of the lower cover 17 itself welded

to the main envelope 14.

  A partition plate 21 divides the housing 12 into a delivery chamber 90 and a pressure suction chamber

  94 receiving the motor 20 in the main envelope 14, for example being blocked or shrunk there. The motor 20 comprises a stator 24 surrounding a rotor 26. The rotor 26 is provided with a central orifice 28 receiving the motor shaft 30, nested therein 30 is mounted for rotation in 35 an offset bearing 36 fixed to the lower end of the main envelope

  blade 14 by nesting. The upper end of the drive shaft 30 is rotatably mounted in an orifice 34 formed in a bearing 32 fixedly installed on the upper face 23 of the stator 24. The upper end of the shaft 30 cooperates with a compression mechanism 22 installed above the bearing 32 by screws 40. The shaft

  drive 30 rotates with the rotor 26 to drive the compression mechanism 22 which compresses the refrigerant in this mechanism.

  The compressor 17 is a spiro-orbital compressor with a compression mechanism 22 formed by a fixed spiral 42 and a mobile or orbital spiral 44. The fixed spiral 42 and the mobile spiral 44 have flat plates 46.50 respectively with spiral windings 48, 52 projecting from these plates. When the fixed spiral 42 and the movable spiral 44 are assembled, the turns 48, 52 are nested and create a set of compression chambers 54 therebetween. The movable spiral 44 is placed between the crankshaft bearing 32 and the fixed spiral 42 so that the rear surface 56 of the plate 52 of the movable spiral is in contact with the thrust surface 58 of the bearing 32. An annular hub 60 is at the threshold of the rear surface 56 of the plate 20 50. This hub has a cavity 62 receiving a bearing 64 and a roller 66. The hub 60, the bearing 64 and the roller 66 are housed in a cavity 65 formed by the bearing 32 The bearing 64 surrounds the roller 66 which is provided with an orifice 67 to receive the eccentric 68 integral with the end of the drive shaft 30 so as to couple in the direction of the drive, the compression mechanism 22 and the shaft

30.

  For the operation of the compressor 10, the motor 20 is electrically supplied in a conventional manner by rotation of the rotor 26 and the drive shaft 30. The pressurized refrigerant gas is sucked into the pressure chamber 94 delimited by the plate separator 21 and the compressor housing 12 for supplying the compression mechanism 22 as will be described later. During the rotation of the drive shaft 30, the movable spiral 44 rotates with respect to the fixed spiral 42. The orbital movement of the movable spiral 44 modifies the volume of the compression chambers 54 so as to compress the re-

  gas refrigerant under inlet pressure at a higher discharge pressure. The compressed compressed gas leaves the compression mechanism 22 through the discharge orifice 88 produced in the flat plate 46 of the fixed spiral 42. The gas at the discharge pressure arrives in the discharge chamber 90 formed between the cover end 16 and

  the outlet of the compressor 10 through the outlet gas tube 92 to supply the refrigeration system, not shown.

  According to Figures 2 and 3, the bearing 32 comprises a main body 69 with an orifice 34 and a cavity 65. A set of branches 70 are distributed around the periphery of the main body 69 and extend downward relative to that -this. The branches 70 are connected to the main body 69 by webs 71 extending radially from the main body 69. At the upper part 73 the branches 70 slightly protrude from the thrust surface 58 of the main body 69 and com15 have flat surfaces 72 with orifices 74. When the compressor 10 is assembled, the fixed spiral 42 of the compression mechanism 22 is in contact with the flat surfaces 72. The screws 40 serve to connect the fixed element 42 and the orifices 64 of the bearing 32 while retaining the movable spiral 44 between the bearing and the fixed element and thus the compression mechanism 22 at the bearing 32. The lower part 75 of the branches 70 descends beyond the lower end of the main bearing part 69 of the bearing 32 and has flat surfaces 76 (FIG. 1) in contact with the upper surface 23 of the stator 24. The branches 70 are fixed to the stator 24 according to an appropriate method. One of these 25 methods can consist in using screws which are passed upwards over the entire length of the stator 24 to come into the branches 70. The branches 70 are elongated so as to spread the mechanism apart

  compression 22 above the motor 20.

  According to the figures, integrally with the bearing 32 in a pair of adjacent branches 70 there is an oil screen surface 78. The upper edge of the oil screen surface 78 is practically level with the flat surfaces 72 of the adjacent branches 70 between which there is the screen 78. The oil screen 78 descends a predetermined distance to be positioned above the outlet end 82 of a suction gas tube 80 (Figure 3) mounted in the compressor housing 12. A mixture of oil and refrigerant passes through the outlet end 82 entering the compressor 10 and comes into contact with the surface 84 of the oil screen 78. When the mixture meets the surface 84, the entrained oil by the coolant 5 clings to the oil screen 78. The oil collects on the surface 84 and eventually drips into the engine 20. The oil descends around the engine 20 as far as the oil tank 86 (figure 1) at the lower end of the housing 12. A small portion of refrigerant at the suction pressure, practically oil-free, is directed downwards over the motor 20 to cool it. The remaining part of the gaseous refrigerant at suction pressure rises in the compression chambers 54 of the compression mechanism 22 to be compressed at the discharge pressure.

  The present invention is not limited to the exemplary embodiments described above but allows for multiple variants.

Claims (2)

RESELL I CATI O NS) Spiro-orbital compressor comprising: - a housing, - a motor mounted in the housing, - a compression mechanism mounted in the housing and coupled so as to cooperate with the motor, - a bearing to which the compression mechanism, - a screen surface integral with the bearing, - a suction tube having an outlet end in the housing and at least part of the screen is practically aligned with the outlet end, in which a mixture of refrigerant gas and oil arrives in the housing through a suction tube, this mixture meeting the screen surface 15 so that the oil separates from the mixture. ) Hermetic spiro-orbital compressor according to claim 1, in which the refrigerant gas from which the oil has been separated is directed by the screen towards the motor. ) Hermetic spiro-orbital compressor according to claim 1, in which the refrigerant gas from which the oil has been separated is directed by the surface forming a screen towards the compression mechanism. ) Hermetic spiro-orbital compressor according to claim 1, characterized in that the oil separated from the oil and refrigerant gas mixture collects on the screen surface and the collected oil descends into an oil tank formed in the housing. ) Hermetic spiro-orbital compressor according to claim 1, characterized in that the bearing has a set of support branches and the screen surface is formed between a pair of adjacent support branches. ) Spiro-orbital compressor comprising: - a housing, - a motor mounted in the housing, - a compression mechanism mounted in the housing and coupled so as to cooperate with the motor, - a bearing mounted in the housing between the compression mechanism 10 and the motor, a screen surface forming a body with the bearing, in which a mixture of oil and refrigerant gas introduced into the housing meets the screen surface and the oil is separated therefrom from the mixture. 15) Hermetic spiro-orbital compressor according to claim 6, characterized in that it comprises a suction tube having an outlet end in the housing, this outlet opening into the housing, the screen surface 20 being placed above from the outlet end and the mixture being introduced into the housing through the suction tube.   8) hermetic spiro-orbital compressor according to claim 6, characterized in that   the refrigerant gas from which the oil has been separated is directed by the surface forming a screen towards the engine.   ) Hermetic spiro-orbital compressor according to claim 6, characterized in that   the refrigerant gas from which the oil has been separated is directed by the screen surface towards the compression mechanism.   ) Hermetic spiro-orbital compressor according to claim 6, characterized in that the oil separated from the mixture, refrigerant gas and oil, collects on the screen surface and the collected oil descends towards the oil tank formed in the housing.   110) Hermetic spiro-orbital compressor according to claim 6, characterized in that the bearing comprising a set of support branches, the screen surface being made in one piece with the bearing between a pair of adjacent support branches. 10) Method for separating an oil and refrigerant gas mixture arriving in a hermetic compressor having a housing with a motor mounted in the housing, a bearing mounted above the motor and a compression mechanism cooperating with the motor, characterized in that the refrigerant gas entrained with the oil is sucked into the compressor through a gas suction tube mounted in the housing and   the refrigerant gas entrained with the oil is directed into contact with a screen surface integral with the bearing, the oil clinging to the screen surface and the refrigerant being directed onto the engine installed in the compressor housing and in the compression mechanism.   ) Method according to claim 12, characterized in that   the oil collected on the screen surface flows into the oil tank formed in the lower part of the compressor housing.