FR2630786A1 - COMPRESSOR DISCHARGE VALVE AND VOLUME HERMETIC COMPRESSOR - Google Patents

Abstract

The invention relates to a discharge valve for a refrigerant compressor. It comprises a flat shutter element 140 intended to come into contact with a valve stop member 120 whose stop surface 122 has several parallel grooves 154 intended to channel the oil deposited by the refrigerant, in order to reduce the tension. surface between the closure element 140 and the stop surface 122, tension due to the deposited oil. Field of application: compressors for refrigerant, etc.

Description

The invention generally relates to a discharge valve of

  compressor, and it relates more particularly to the configuration of a discharge valve or a stop-valve reducing the oil tension between the valve and its stop. The usual refrigerant compressor for a refrigeration system includes a number of moving parts whose operation requires lubrication. This is usually done by means of a lubricating oil, part of which is usually entrained in the coolant and circulated through the compressor to lubricate the moving parts. When the refrigerant fluid carrying the oil passes through the compressor, oil is deposited on the compressor parts. Although this gives the desirable result of lubricating the compressor parts in order to extend their service life and reduce their maintenance, this oil deposit often impairs the operation of certain compressor components.

  refrigerant. For example, in many

  typical rotary coolers, it is

  necessary to implement a discharge valve.

  This valve serves to prevent a reverse rotation of the compressor elements under the effect of refrigerant reflux at high pressure or backflow when

  the refrigerant compressor is not running.

  A configuration of a conventional refrigerant compressor discharge valve is shown in Japanese Patent No. 62-150,592. This valve is simply an elastic valve retained by a bolt or screw. It can easily be seen that there are two serious disadvantages to this valve, the first being specific to the flexible nature of the valve, because the material selected for the valve may be subject to fatigue failure caused by the constant periodic movements of the valve between the open and closed positions, and the second being the surface tension developed between the valve and the element on which it rests, as a result of the oil deposited on them from the refrigerant fluid resulting in 'oil. It is therefore desirable to have a valve that is not

subject to these limitations.

  Another approach is to use a separate valve member moving between a closed position overlying a discharge port and an open position in which the member is pressed against a valve stop. While this eliminates the risk of failure of the valve member due to fatigue, this embodiment does not solve the problem of the oil tension developing between the valve element and the adjacent parts. This problem is recognized, for example, in the patent of the United States of America

  NI 4,580,604. A number of

  valve and valve seat parts are provided to minimize the oil film between the valve member and the seat; however, no attempt is made to minimize the tension of the oil developed between the valve member and its stop. it can easily be seen that the oil fluid developed between the valve member and its abutment towards the open position similarly prevents the refrigerant from immediately forcing the valve member into the closed position; which therefore allows a period of reflux of the refrigerant fluid. This condition appears when the compressor stops working and the

  refrigerant pressure in the discharge port

  becomes inferior to that prevailing outside

the discharge port.

  In view of the foregoing, it is an object of the invention to provide a compressor discharge valve which is rapidly responsive to variations in

  pressure in the discharge port of the compressor.

  Another object is to propose a valve of

  backflow of this type, simple and inexpensive to manufacture.

  Another object of the invention is to provide a discharge valve of this type having a long

  service life and low business requirements

  yours. Another object of the invention is to provide a discharge valve of this type which is not subject to malfunction due to the oil deposited by the

  refrigerating fluid driving oil.

  The invention relates to a compressor discharge valve for use in a refrigerant compressor compressing a refrigerant fluid carrying oil. The discharge valve consists of a separate shutter element working

  between an open position and a closed position

  ture, and a valve stop member for contacting the shutter member in the position

  opening to limit the stroke. The ob-

  The turner is generally planar, while the stop member has a surface for contacting the shutter member. This surface includes an oil pipe portion consisting of a series of surfaces bearing against the shutter member and a series of spaced surfaces of the shutter member to allow the oil to be collected and channeled. within the spaces between the surfaces in contact with the shutter member. This channeling of the oil deposited by the refrigerant fluid driving the oil allows the refrigerant fluid to penetrate between the abutment element and the closure element while at the same time preventing the oil from settling between these two elements. , and thus avoid the appearance of a tension

of oil between them.

  The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting examples and in which:

  FIG. 1 is a longitudinal sectional view

  partial discharge valve of a compressor, visible in the partial sectional part of a rotary hermetic fluid compressor. refrigerant, scroll type; FIG. 2 is a partial view from above of the compressor discharge valve, visible in a part partly in section of the refrigerant compressor, along line 2-2 of FIG. 1; FIG. 3 is a sectional view along line 3-3 of FIG. 2 of the compressor discharge valve showing the closure element in the closed position; - Figure 3A is a top view of the shutter element of the discharge valve. compressor; FIG. 4 is a sectional view along the line 3-3 of FIG. 2 of the compressor discharge valve showing the closure element in the open position; Figure 5 is a view of the valve stop surface taken along line 5-5 of Figure 3; FIG. 6 is a sectional view along line 3-3 of FIG. 2 of an alternative embodiment of the compressor discharge valve; Figure 7 is a plan view of the valve abutment surface of the abutment member of the alternative embodiment taken along the line 7-7 of Figure 6; FIG. 8 is a sectional view, along line 3-3 of FIG. 2, of a second variant of FIG.

  realization of the compressor discharge valve;

  FIG. 9 is a plan view of the

  second variant embodiment of the discharge valve

  compressor, along the line 9-9 of Figure 8; FIG. 10 is a sectional view along line 3-3 of FIG. 2 of a third variant of the compressor discharge valve; Fig. 11 is a plan view of the closure member of the third embodiment, taken along line 11-11 of Fig. 10; - Figure 12 is a sectional view, along the line 3-3 of Figure 2, a fourth embodiment of the compressor discharge valve; FIG. 13 is a plan view of the shutter element of the fourth variant embodiment along the line 13-13 of FIG. 12; Fig. 14 is a sectional view along line 3-3 of Fig. 2 of a fifth embodiment of the compressor discharge valve; and - Figure 15 is a top view of

  the shutter element of the fifth form of embodiment

  along the line 15-15 of Figure 14.

  A refrigerant compressor system is generally designated by numeral 1 in FIG. 1. The refrigerant compressor system 20 is a rotary compressor housed in a hermetic enclosure 22. The refrigerant compressor system 20 is not shown in detail in FIG. 1, as the compressor details need not be explained to understand the form and operation of the present invention. In a real application of the present invention, a scroll-type refrigerant compressor system is used. It is understood that a piston compressor rolling, screw or other

  Rotary compressor would also be suitable.

  A fixed volute 24 having a central opening defining a discharge orifice 26 is disposed inside the hermetic envelope 22. A volute 28 with orbital movement is disposed at a distance from and parallel to the fixed volute 24. A spiral or a fixed involute winding 30 is disposed on the fixed scroll 24, and a spiral or winding 32 in involute with orbital motion is disposed on the scroll

  28 with orbital motion so that the spirals developing

  respective troughs are in nested engagement defining a plurality of cells whose volume decreases towards the center of the respective spirals. An oscillating link mechanism 34 produces an orbital, non-rotational motion of

the volute 28 with orbital movement.

  The fixed scroll 24 further serves to divide the hermetic enclosure 22 into a portion 36 at the discharge pressure and a portion 38 at the suction pressure. It is understood that the division of the hermetic enclosure 22 to form the portion 36 at the discharge pressure and the portion 38 at the suction pressure could be ensured, in the rotary compressor, by other means, such as an independent partition, and that the use of the fixed scroll element 24 should not be understood as being limiting. A suction port 40 is provided for admitting a coolant at the suction pressure in the portion 38 at the suction pressure of the sealed envelope 22, and a discharge port 42 is provided to allow the coolant at the discharge pressure to get out of the 36 part at the pressure of

  return of the hermetic envelope 22.

  The refrigerated compressor system 20

  The electric motor 50 is driven by an internal electric motor 50 disposed within the portion 38 at the suction pressure of the sealed envelope 22. The electric motor 50 comprises a stator 52 and a rotor 54. A drive shaft 56 passes through the rotor 54, its lower end immersed in an oil reservoir 58. A centrifugal pump 60 & oil, disposed at the lower distal end of the drive shaft 56, acts to circulate the oil 58 upward in an inner lumen 62 of the drive shaft 56. The oil thus upwardly pushed up into the inner lumen 62

  lubricates surfaces subject to friction within

  compressor system, such as the bearings

  top and bottom.64 of the training tree

  is lying. After having passed through the bearings 64 and having lubricated them, the oil returns to the tank 28, descending through and around the windings of the stator 52 and the rotor 54, the frame 66 and the interior of the

  part 38 at the suction pressure.

  Bearings 64 of the drive shaft are supported in a frame 66 which is attached to the airtight envelope 22 and which includes other bearings and a structure necessary to support the volute scroll member 28 with orbital motion. This frame 66, as well as the bearings and structures for supporting the motor 50, are not described in detail because they are considered to be generally well known to those skilled in the art and are not essential to

understanding of the invention.

  Referring now generally to Figs. 1 to 15, these show a compressor discharge valve assembly 100 as a whole disposed above the fixed scroll member 24,

  immediate proximity to the discharge port 26.

  The delivery valve assembly 100 advantageously comprises

  a valve stop member 120, a valve member or shutter member 140 and means for

  maintain the stop element in a global arrangement-

  parallel to and spaced from the fixed scroll member 24.

  The preferred embodiment further comprises means for guiding the closure member between an open position and a closed position. The means for maintaining the position of the valve stop member and the means for guiding the closure member 140 will all be described more fully below. The closure member 140 is disposed with respect to the delivery port 26 of the stationary scroll member 24 so that in the closed position the closure member 140 prevents the refrigerant from passing through. flow from the portion 36 to the discharge pressure in the discharge port 26. In the open position, the sealing member 140 rests against a surface 122 of the abutment member, thereby allowing the coolant to flow from the discharge port 26 to the portion 36

  at the discharge pressure of the hermetic envelope 22.

  In operation, the electric motor 50 is energized to rotate the rotor 54 and the drive shaft 56. This rotation is transmitted by

  the mechanism 34 oscillating rod so that it

  This causes an orbital, non-rotational movement of the orbital scroll member 28 relative to the fixed scroll member 24. The fixed involute spiral and the orbital involute spiral 32, nested within each other. other, form several cells whose volume decreases radially outer ends of

  respective spirals towards the center of these.

  While the electric motor 50 is running, refrigerant gas is drawn into the portion 38 at the suction pressure through the orifice 40

  from the refrigeration system or circuit.

  tion (not shown). The refrigerant gas then flows through the parts of the electric motor 50, this flow of refrigerant gas coming into contact with a part of

  the oil returning to the oil reservoir 58 and driving it.

  The refrigerant fluid driving oil is then

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  compressed in the cells defined by the imbricated coils.

  respective volutes and is ejected through the discharge port 26. The refrigerant

  ejected, causing oil, pushes back the shutter element

  140 to the open position, allowing the coolant, now at the discharge pressure, to escape the portion 36 to the discharge pressure and be returned to the refrigerant system.

  passing through the discharge port 42.

  As soon as the power supply of the electric motor 50

  is cut off, the shutter member 140 moves im-

  mediately to a closed position in which it is placed on the discharge port 26 to cover it. This prevents a reflux of the refrigerant of the portion 36 at the discharge pressure to the orifice 26

of repression.

  This is shown more clearly in FIGS. 3 and 4, where the shutter element 140 is shown in section. In FIG. 3, the shut-off element is shown in the closed position in which it covers the light defining the discharge orifice 26 in a sealed manner. In FIG. 4, the shut-off element 140 is shown disposed against the surface 122 of the valve stop member 120, allowing the

  refrigerant to flow through the discharge port

26.

  Referring generally to FIGS. 3 to 15, the means for holding the valve stopper in position relative to the fixed scroll member 24 is explicitly described. These means comprise two bolts 124, each passing through a corresponding hole 126 and penetrating threaded holes 25 whose threads are dimensioned to closely receive the bolts 124. The holes 126 are formed at the respective distal ends of the abutment element 120. valve, and the holes 126 and 25 are further arranged in axial alignment. A tubular guide sleeve 130 is secured in close proximity to each distal end of the valve stopper member 120 between said member 120 and the fixed scroll member 24. Each guide bushing 60 has an outer guide surface 132 against

  which can slide a part of the shutter element

  140. Each guide bushing 130 is aligned coaxially with the holes 126 of the valve stop member 120 so that the bolts 124 pass through the guide bushes and serve to retain them in position. The guide bushes 130 hold the valve stop member 120 in a parallel arrangement spaced apart by

  relative to the fixed scroll element 24.

  The general shape of the closure element, as seen in FIG. 3A, is that of a substantially thin planar element having opposite ends 144 each comprising two hemispherical lobes 145 and a curved portion 146 of a circle defined between they fit tightly around the guide surface 132 of the guide sleeve 130. The radius of the curved portion 146 of the end 144 is sized to establish a set of several hundredths of a millimeter to allow free movement of the closure member and thus avoid any blockage or seizure between this

  shutter member 140 and guide sleeves 130.

  The valve stop surface 122 includes a portion 150 for piping the oil. The oil line portion 150 is disposed at least between the holes 126 of the valve stop member 120. however, the oil line portion 150 may extend over the entire stop surface 122. In the preferred embodiment, the oil pipe portion 150 is formed of a series of grooves 154. The grooves 154 have two sides 156 extending from the abutment surface 122 to a bottom 158 which is parallel to the abutment surface 122 and spaced a distance D from this surface 122. Each groove 154 is spaced from the corresponding groove and adjacent by a rib 152 of width L. Each groove is at a distance W from the throat immediately adjacent. The distance or width W is the sum of the width of the bottom 158 and the rib 152. The preferred embodiment, shown in FIGS. 3 to 5, includes grooves for which W is between 3.05 and 3.81. mm, the width of the ribs L is between 1.40 and 2.03 mm and the depth D of the grooves 154 is

between 0.05 and 0.025 mm.

  Figures 6 and 7 show a first embodiment. As before, valve stop member 10a1 is secured by bolts 124a passing through holes 126a to penetrate threaded holes a of fixed scroll member 24a. The valve stop member 120a is held at a distance from the fixed scroll member 24a by guide sleeves 130a disposed axially about the bolts 124a. The grooves 154a comprise two sides 156a extending obliquely inwardly of the valve abutment member 1ola to define and form an angle therebetween. This angle may be, for example, between 60 and 100, although it is advantageously 90 °. As in the preferred embodiment, grooves are separated by ribs 152a. The width L1 of the ribs 152a must be between 1.27 and 2.54 mm and the total width W1 between the respective grooves 154a could advantageously be

between 2.54 and 3.8 mm.

  A second variant embodiment is shown in FIGS. 8 and 9. This second variant comprises a valve abutment element 120b which is molded in one piece with guide bushes 130b. The portion 150b of oil pipe of this form of

  realization comprises several bosses 160b which

  protuberances which may be in the form of hemispheres or cones protruding from the abutment surface 122b to the fixed scroll member 24b to contact the closure member 140b. These

  bosses 160b may have a diameter which is advantageously

  2.5 to 5 mm at their base and can protrude over a distance D2 between 0.13 and 0.38 mm from the abutment surface 122b. Although it is possible to form these bosses 160b by machining the abutting abutment surface 122b, the bosses 160b are more conveniently formed by molding or forging the valve abutment member b to include these bosses 160b. It should also be noted that the use of a molded or forged valve stop member 120 made integrally with guide bushes 130 is possible for any one of the embodiments of the invention. the present invention and therefore should not be construed as being limited to one

  any of the embodiments.

  A third embodiment of the invention, shown in FIGS. 10 and 11, comprises a flat surface 122c for abutment on the stop element 120c of FIG.

  valve. In this embodiment, the element.

  shutter 140c has an abutment surface 142c having a portion 170c of oil pipe. Part 170c comprises a series of ribs 172c and grooves 174c. As in the preferred embodiment, the grooves 174c are defined by perpendicular sides 176c extending inwardly of the body of the shutter member 140c to a bottom 178c located at a depth D3. The depth D3 should be between 0.05 and 0.25 mm. The sides 176c of the grooves 174c are parallel to each other and parallel to the sides 176c of the respective adjacent grooves 174c. The grooves 174c are spaced a distance W3 which is the sum of the width of the bottom 178c and the width L3 of the rib 172c, and which

  should be between 0.025 and 3.8 mm.

  Figures 12 and 13 show a fourth embodiment. As in the previous embodiment, the shutter member 140d includes a portion 170d of oil line having a plurality of bosses 180d. These bosses 180d should be spaced a distance w between 2.5 and 5 mm. Each boss 180d may be of hemispherical or conical shape, with a diameter d4 at the base of between 2.5 and 5 mm and a height D4 of between 0.05 and 0.25 mm in order to come into contact with the plane surface 127d of the valve stop member 120d. The bosses can be formed by

  forging or stamping the shutter member 140d.

  A fifth variant embodiment is shown in FIGS. 14 and 15, a variant in which the

  170th part of the oil pipe of the shutter element

  140e presents a series of grooves 174e sinking obliquely in the body of the shutter element 140e and ending at an angle between them. As with the first embodiment, the grooves 174e defined by the sides 176e are parallel and spaced from each other by ribs 172e of width L5 which is between 1.27 and 0.25 mm so that the width total W5 between the adjacent gorge 174e

is between 2.5 and 3.8 mm.

  The numerical values indicated here are intended to facilitate the understanding of the invention and are in no way to be taken as a limitation

  as to the implementation or interpretation of the spirit-

  of the invention, because the actual valves vary according to the different embodiments in accordance with the

principles described here.

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  The elements of the present invention are

  advantageously formed in steel alloys con-

  and, unless indicated for certain embodiments, the grooves 154 of the valve stop member 120 and the grooves 174 of the closure member 140 are readily formed by forging or milling the respective pieces. These manufacturing techniques are well known to those skilled in the art and it is useless to describe them here. Referring generally to FIGS. 3 to 15, it can be seen that the shape of valve stop member 120 is generally straight, this member having upper, lower, and lateral, flat and parallel surfaces. The embodiments of the element 120

  valve stoppers shown comprise protuberances

  those which are hemispherical or rounded parts of an included circle. Neither the specific shape nor the specific protuberances are necessary for the operation of the present invention, provided that the valve stop member 120 includes a portion 150 of the oil line or the shutter member 140 includes a portion 170 oil pipeline to channel the oil from

  the assembly 100 with discharge valve.

  The operation of the compressor system 20 having been described generally above, it is

  It is easy to see that the assembly 100 with a discharge valve.

  It is located directly in the path of the refrigerant fluid driving the discharged oil through the discharge port 26. Part of the oil entrained in the coolant is deposited on

  the shutter element 140 and its abutment element 120.

  When the sealing element 140 is forcibly moved towards the opening position against the abutment surface 122 by the pressure of the discharge refrigerant, the oil thus deposited flows into the grooves 154 or 174 is channeled from away from the discharge valve assembly 100. When the compressor system ceases to operate, no significant amount of oil remains between the sealing member 140 and the stop member 120, which allows the closure member 140 to respond instantly to removing the pressure from the discharge refrigerant and thus quickly fall to the closed position to prevent a

inverse rotation of the compressor 20. It goes without saying that many modifications can be made to the -

  discharge valve and the compressor described and shown without departing from the scope of the invention.

Claims (16)

  A discharge valve of a refrigerant compressor (20) operating to compress a refrigerant fluid carrying oil, characterized in that it comprises a fixed element (24) in which a discharge orifice ( 26), a separate, generally planar, discharge valve member (140) having an open position and a closed position in which said valve or closure member is arranged to selectively cover the in a flow-preventing manner, a generally planar valve stop member (120) having an abutment surface (122) for engaging the closure member in the open position; stop having a portion (150) of oil line   intended to collect and channel the residual liquid oil   the oil-cooled coolant deposited on the abutment surface to minimize the   surface tension of the oil between the shutter element   in the open position and the abutment surface to thereby prevent the sealing member from sticking to the   stop surface in the open position.   The compressor discharge valve according to claim 1, characterized in that it further comprises means (130) for supporting the valve stop member in a generally parallel arrangement.   to and spaced from said shutter member.   3. Compressor discharge valve according to claim 2, characterized in that the support means of the stop element further comprise means (130) for guiding the closure element.   between the open position and the closed position.   4. Compressor discharge valve according to claim 3, characterized in that the oil pipe portion further comprises a plurality of paths connected-them.   5. The compressor discharge valve according to claim 3, characterized in that the oil pipe portion further comprises a plurality of spaced bosses (160b) projecting towards the closure member. The compressor discharge valve according to claim 3, characterized in that the oil pipe portion further comprises a series of grooves. (154) of depth (D).   io Compressor discharge valve according to claim 6, characterized in that each groove is spaced apart and parallel to the adjacent groove, to a width (W) of this groove.   Compressor discharge valve according to claim 7, characterized in that the grooves are   further defined by several ribs (152) of separa- width (L).   Coolant compressor cooling valve operable to compress a refrigerant fluid carrying oil, characterized in that it comprises a fixed element (24c) in which a discharge orifice (26c), a a generally planar valve stop member (120) having a valve stop surface (122), means (130c) for   support the stop element in a global arrangement   parallel to and spaced from the fixed member, the support means of the stop member further comprising means (130) for guiding a closure member (140c) of the discharge valve, generally planar and separated, having an open position and a closed position, said closure member further having a contact surface (142c) with the abutment member, for bearing against the abutment surface in the open position the contact surface further comprising an oil pipeline portion (170c) for collecting and channeling residual liquid oil deposited on the contact surface by the oil-carrying coolant, the shutter being further arranged to selectively cover the discharge port in a manner preventing flow. The compressor discharge valve according to claim 9, characterized in that the oil channel portion of the contact surface with the stop member further comprises a plurality of paths. interconnected.   Compressor delivery valve according to claim 9, characterized in that the oil channel portion of the contact surface with the stop element further comprises a plurality of bosses.   spaced apart (160b) projecting toward the abutment surface.   Compressor discharge valve according to claim 9, characterized in that the oil channel portion of the contact surface with the stop element further comprises a series of grooves. (174c) of depth (D).   13. A compressor discharge valve according to claim 12, characterized in that each groove is spaced a width (W) from each groove adjacent to which is parallel.   14. Compressor discharge valve according to.   claim 13, characterized in that the grooves are   further defined by a plurality of ribs (172c) of separa- width (L).   Airtight scroll compressor comprising an anti-reflux discharge valve (100), characterized in that it comprises a first volute element (24) disposed inside the hermetic compressor in order to divide it into a part (38). ) at the suction pressure and at a portion (36) at the discharge pressure, the scroll element having a discharge port (26) for directing coolant towards the discharge pressure portion; first scroll element further carrying a first involute vertical turn (30), a second scroll member (28) disposed in the hermetic compressor to orbit relative to the first scroll member, the second member to   volutes having a second vertical turn (32) developing   for making an interlocking grip with the first vertical turn, means (50, 34) for orbitalally driving the second scroll element disposed in the suction pressure portion of the   hermetic compressor, a separate element (140) for sealing   part of the discharge valve, having an open position and a closed position in which the closure member is arranged to selectively cover the discharge port in a manner preventing flow, a valve stop member (120) having a surface. Stopper (122) for engaging the closure member in the open position, the abutment surface having a portion (150) of oil line for collecting and channeling residual liquid oil deposited on the abutment surface by the refrigerant fluid entraining oil, to minimize any surface tension of the oil between the sealing member in the open position and the abutment surface to prevent the sealing member to stick to the abutment surface in the opening position.   Airtight scroll compressor comprising an anti-reflux delivery valve (100), characterized in that it comprises a first scroll element (24) arranged in the hermetic compressor in order to divide it into a portion (38) at the suction pressure and a portion (36) at the discharge pressure, the scroll element having a discharge orifice (26) for directing a coolant towards the discharge pressure portion, the first scroll element further comprising a first involute vertical coil (30), a second scroll member (28) disposed in the hermetic compressor for orbital movement relative to the first scroll element, and the second scroll element bearing a second turn vertically (32) to develop a nested socket with the   first vertical turn, means (5C, 34) for.   orbiting the second scroll member disposed in the suction pressure portion of the hermetic compressor, a valve stop member (120) having a stop surface (122), a separate member (140c), closure member forming part of the discharge valve and having an open position and a closed position, said closure member further having a surface (142c) for engaging the abutment surface in the position of opening, the contact surface (142c) further comprising an oil channel portion (170c) for collecting and channeling residual liquid oil deposited on this contact surface by the oil-carrying coolant, the closure member being further arranged to selectively cover the discharge port   in a way that prevents any flow.