Compressor comprising a pressure-relief groove

Abstract

A compressor is disclosed. In one aspect, the compressor includes a pressure chamber which is delimited by at least two housing parts, the housing parts including sealing surfaces that are connected by a connection device which applies a contact pressing force between the sealing surfaces. At least one groove extending in a circumferential direction is arranged on at least one sealing surface. At least one relief opening is arranged on at least one of the housing parts. The relief opening connects the groove to the surroundings of the compressor and emanates from the groove. The groove is arranged such that when a predetermined maximum pressure is exceeded in the pressure chamber, a pressure-building medium can gather in the groove and at least partially escape through the relief opening.

Claims

1. A compressor for use in air conditioning systems of a motor vehicle, the compressor comprising: a housing including a first housing part and a second housing part which together define a pressure chamber, said first housing part having a first sealing surface and said second housing part having a second sealing surface, said first and second housing parts being connected by a plurality of connecting elements applying a contact pressure on said first and second sealing surfaces; a first groove formed in said first sealing surface of said first housing part and extending in a circumferential direction; a first vent opening including a radially-extending first relief channel formed in said first housing part and extending from said first groove to the environment of the compressor, wherein said first groove and first vent opening are configured such that a pressurized medium is collected in said first groove and at least partially discharged from said first groove to the environment via said first vent opening in response to the pressurized medium within said pressure chamber exceeding a predetermined maximum pressure; a second groove formed in said second sealing surface of said second housing part and extending in a circumferential direction; and a second vent opening including a radially-extending second relief channel formed in said second housing part and extending from said second groove to the environment of the compressor, wherein said second groove and said second vent opening are configured to cooperate with said first groove and said first vent opening to allow pressurized medium collected in at least one of said first and second grooves to be discharged to the environment from at least one of said first and second vent openings in response to the pressurized medium within said pressure chamber exceeding said predetermined maximum pressure.

2. The compressor of claim 1 wherein said first relief channel extends between said first groove and an exterior surface of said first housing part, and wherein said relief channel extends between said second groove and an exterior surface of said second housing part.

3. The compressor of claim 2 wherein said first and second grooves are concentrically aligned, and wherein said first relief channel is aligned with respect to said second relief channel.

4. The compressor of claim 2 wherein said first and second grooves are concentrically aligned, and wherein said first relief channel is circumferentially offset relative to said second relief channel.

5. The compressor of claim 1 wherein said first housing part further includes a plurality of circumferentially aligned through-holes configured to align with a plurality of circumferentially aligned threaded bores formed in said second housing part, wherein said connecting elements included a plurality of housing screws each extending into an aligned pair of through-holes in said first housing part and threaded bores in said second housing part, wherein said housing screws are tightened to apply said contact pressure on said first and second sealing surfaces, and wherein said first relief channel extends between said first groove and one of said through-holes so as to permit the pressurized medium collected in said first groove to be discharged via said first relief channel and a first flow path provided in said through-hole to the environment.

6. The compressor of claim 5 wherein said second relief channel extends from said second groove to one of said threaded bores formed in said second housing part so as to permit pressurized medium collected in said second groove to be discharged via said second relief channel and a second flow path provided in said threaded bore which communicates with said first flow path provided in said through-hole in said first housing part to the environment.

7. The compressor of claim 5 wherein said first flow path provided in said through-hole communicates with a radial bore formed in said first housing part and which extends between said through-hole and an outer surface of said first housing part such that the pressurized medium collected in said first groove is discharged to the environment via said first relief channel, said first flow path and said radial bore.

8. The compressor of claim 1 wherein said first housing part includes a plurality of through-holes configured to be aligned with a plurality of threaded bores formed in said second housing part, wherein said connecting elements are housing screws each extending into an aligned pair of through-holes and threaded bores, wherein said housing screws are tightened to apply said contact pressure on said first and second sealing surfaces, and wherein said first relief channel formed in said first housing part extends radially between said first groove and an exterior surface of said first housing part, said first relief channel being oriented circumferentially to extend between a pair of adjacent through-holes such that said first relief channel does not communicates with any of said through-holes.

9. The compressor of claim 8 wherein said second relief channel formed in said second housing extends radially between said second groove and an exterior surface of said second housing part, and wherein said second relief channel is oriented circumferentially to extend between a pair of adjacent threaded bores such that said second relief channel does not communicate with any of said threaded bores.

10. The compressor of claim 9 wherein said first and second grooves are concentrically aligned, and wherein said first and second relief channels are circumferentially aligned.

11. A compressor for use in an air conditioning system of a motor vehicle, comprising: a housing including a first housing part and a second housing part which together define a pressure chamber, said first housing part having a first sealing surface and said second housing part having a second sealing surface, said first and second housing parts being connected by a plurality of connecting elements applying a contact pressure on said first and second sealing surfaces; a groove formed in one of said first sealing surface of said first housing part and said second sealing surface of said second housing part, said groove extending in a circumferential direction; and a vent opening formed in at least one of said first and second housing parts and providing a communication path between said groove and the environment of the compressor, wherein said groove is arranged such that a pressurized medium is collected in said groove and is at least partially discharged via said vent opening to the environment in response to the pressurized medium within said pressure chamber exceeding a predetermined pressure, wherein said vent opening is a radially-extending relief channel communicating with said groove and with an external surface of said housing, wherein said groove comprises a first groove formed in said first sealing surface and a second groove formed in said second sealing surface, and wherein said relief channel comprises a first relief channel formed in said first sealing surface and which extends radially between said first groove and an external surface of said first housing part, and a second relief channel formed in said second sealing surface and which extends radially between said second groove and an external surface of said second housing part.

12. The compressor of claim 11 wherein said first and second grooves are concentrically aligned, and wherein said first relief channel is aligned with respect to said second relief channel.

13. The compressor of claim 11 wherein said first and second grooves are concentrically aligned, and wherein said first relief channel is circumferentially offset relative to said second relief channel.

14. The compressor of claim 11 wherein said first housing part includes a plurality of through-holes configured to be aligned with a plurality of threaded bores formed in said second housing part, wherein said connecting elements are housing screws each extending into an aligned pair of through-holes and threaded bores, wherein said housing screws are tightened to apply said contact pressure on said first and second sealing surfaces, wherein said first relief channel is oriented circumferentially to extend between a pair of adjacent though-holes such that said first relief channel does not communicate with any of said through-holes, and wherein said second relief channel is oriented circumferentially to extend between a pair of adjacent threaded bores such that said second relief channel does not communicate with any of said threaded bores.

15. A compressor for use in an air conditioning system of a motor vehicle, the compressor comprising: a first housing part defining a first portion of a pressure chamber extending from a first sealing surface and an annular groove surrounding said first portion of said pressure chamber; a second housing part defining a second portion of said pressure chamber and having a second sealing surface; a plurality of connecting elements configured to connect said first and second housing parts and apply a contact pressure to said first and second sealing surfaces so as to delimit said pressure chamber therebetween; and a venting arrangement providing a fluid communication path between said groove and an exterior surface of at least one of said first and second housing parts, wherein said groove is placed in communication with said pressure chamber when a pressurized medium within said pressure chamber exceeds a predetermined maximum pressure and causes a gap to form between said first sealing surface and said groove, and wherein the pressurized medium collected in said groove is at least partially discharged via said vent opening to the environment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments can be seen from the following description in connection with the figures.

(2) FIG. 1 illustrates a sealing surface of a housing part of a compressor according to one embodiment.

(3) FIG. 2 illustrates a typical compressor at maximum pressure.

(4) FIG. 3 illustrates a compressor comprising a relieving groove at operating pressure according to one embodiment.

(5) FIG. 4 illustrates a compressor including the relieving groove of FIG. 3 at maximum pressure according to one embodiment.

(6) FIG. 5 illustrates a compressor including the relieving groove at maximum pressure according to another embodiment.

(7) FIG. 6 illustrates a compressor including the relieving groove at maximum pressure according to another embodiment.

(8) FIG. 7A illustrates the radial pressure gradient in the sealing surface between two housing parts of the typical compressor at operating pressure.

(9) FIG. 7B illustrates the radial pressure gradient in the sealing surface between two housing parts of the typical compressor at maximum pressure.

(10) FIG. 7C illustrates the radial pressure gradients in the sealing surface between two housing parts of the compressor at the operating pressure and at the maximum pressure according to some embodiments.

DETAILED DESCRIPTION OF CERTAIN ILLUSTRATIVE EMBODIMENTS

(11) FIG. 1 shows a sealing surface 25 of a housing 20 of a compressor 10 according to one embodiment. The sealing surface 25 is planar and delimited by two essentially concentric circles with different radii. In the sealing surface 25 several recesses or screw holes 21 are arranged, wherein these screw holes 21 are extending orthogonally from the sealing surface of 25 into the housing 20. For this embodiment, nine screw holes excluded from the housing 20 in the sealing surface 25 are arranged in substantially equal distances on the circumference of the sealing surface 25. The radial distances of the individual screw holes 21 from the inner edge of the sealing surface are substantially identical. The sealing surface of 25 has a groove 40 according to some embodiments. This groove 40 extends in the circumferential direction of the housing 20 or the sealing surface 25, respectively in an substantially constant radial distance to the inner edge of the sealing surface. For the described embodiment, the groove 40 extends in the sealing surface of 25 in the radial position, in which the screws holes 21 are also arranged. Therefore, the groove 40 cuts all nine screws holes 21 of housing 20 and is disrupted in nine positions. The radial width of the groove 40 is small in relation to the radial width of the screw hole 21.

(12) FIG. 2 shows a typical compressor 10 with a pressure chamber under a maximum pressure 13. This compressor 10 includes a housing 20 having a sealing surface 125 and a housing cover 30 having a sealing surface 135. The housing 20 and the housing cover 30 are connected in such a way that inside of the compressor 10 the pressure chamber 13 is formed, wherein a rubber metal sealing 60 is arranged in the range of the sealing surfaces 125 and 135. The two housing parts 20 and 30 are connected using several housing screws 150, which are inserted through screw through-holes 32 in the housing cover 30 and are screwed in the threaded holes 21 in the housing 20. In FIG. 2, the compressor 10 is shown with the application of the maximum pressure within pressure chamber 13 corresponding to the bursting pressure. In this operating mode, the sealing surfaces 135 of the housing cover 30 and the sealing surface 125 of the housing 20 diverge by surface pressure on the inner walls of the pressure chamber 13 of the compressor 10 applied by the maximum pressure. By this way, a gap 31 between the two sealing surfaces 135 and 125 is formed. Through the opening of this gap of 31, a pressurization medium E can enter from the original pressure chamber into this gap 31 and apply there a surface pressure against the connection pressure applied by the housing screws 150. For the maximum pressure, thus the diameter of the pressurized area D.sub.H in the compressor increases. For the typical compressor 10, it is therefore necessary to make the dimensions so big that it can withstand the rising surface pressure for the same time increasing diameter of the pressurized area D.sub.H as long as until only the outer edge is sealed to avoid a failure of the screw connection.

(13) FIG. 3 shows a compressor 10 with a relieving groove at operating pressure according to one embodiment. The configuration shown here differs from the compressor 10 of FIG. 2 in that the housing screws 50 are constructed smaller which, because of the arrangement of the grooves 40a and 40b formed in the corresponding sealing surfaces 35 and 25 according to some embodiments, need not be constructed as large as the connecting screws 150 of FIG. 2. The compressor 10 of FIG. 3 is shown with a pressurization at the operating pressure in the pressure chamber 12 so that the diameter of the pressurized surface at operating pressure D.sub.B is less than the diameter D.sub.HS shown in FIG. 2 since at the operating pressure, the sealing surface 35 of the housing cover 30 and the sealing surface 25 of the housing 20 do not diverge. In some embodiments, the compressor 10 includes a groove 40a formed in the sealing surface 35 of the housing cover 30 and a groove 40b formed in the sealing surface 25 of the housing 20. These grooves extend in the circumferential direction of the respective sealing surface, and extend in the embodiment over the entire circumference. At each position in the periphery of the respective sealing surface, on which are arranged the threaded holes 21 and screw through-holes 32, a discharge channel 27 or 37 extends in the radial direction in the sealing surface 25 of the housing 20 or the sealing surface 35 of the housing cover 30. The grooves 40a and 40b are constructed such that pressurization medium E can accumulate in them. Similarly, the relieving channels 27 and 37 are formed such that they can conduct the pressurization medium E accumulated in the respective groove 40 to the screw through-holes 32.

(14) FIG. 4 shows the compressor of FIG. 3 with application of the maximum pressure on the pressure chamber 13 according to one embodiment. In this operating mode, the housing parts 20 and 30 diverge in the region of the inner sealing surfaces 25 and 35 so that a gap 31 is formed. By the formation of this gap 31, the diameter of the pressurized surface is enlarged to the diameter of D.sub.HE, which is smaller than the diameter of the pressurized surface D.sub.HS at maximum pressure in the compressor 10 of FIG. 2. At maximum pressure, the gap 31 opens between the sealing surfaces 25 and 35 radially outwardly to the grooves 40a and 40b, after which those are filled with pressurization medium E, which is discharged through the relieving channels 27 and 37 to the respective screw through-hole 32 and via those it can escape into the surroundings 11 of the compressor 10. For example, a groove is provided in the head of those housing screws 50 of which screw through-holes 32 the pressurization medium is conducted. The radial position of the grooves 40a and 40b limits the maximum possible diameter D.sub.HE of the pressurized area and the maximum pressure in such a way that a smaller construction of the housing screws 50 is possible because the force which can be applied and which may detach the screw connection parts 21, 32 and 50 is also limited by the limitation of the diameter D.sub.HE.

(15) FIG. 5 shows a compressor 10 with a relieving groove at maximum pressure according to another embodiment. In the configuration shown here, the discharge of the pressurization medium E from the grooves 40a and 40b is done also via the relieving channels 27 and 37 respectively formed in the sealing face 25 of the housing 20 and the sealing surface 35 of the housing cover 30. In regard to the sealing surfaces, the relieving channels 27 and 37 are arranged along the grooves 40a and 40b, not on the circumferential positions of the housing screws 50, but on the circumferential positions between the connecting elements. The relieving channels 27 and 37 in this case extend radially from the grooves 40a and 40b to the outer radial edge of that housing part 20 or 30, from which they are excluded, and thus establish a connection to the environment 11 of the compressor at ambient pressure, to which the pressurized medium E can be discharged from the pressure chamber 13 of the compressor 10 via the gap 31, the grooves 40a and 40b and the relieving channels 27 and 37. For the described embodiment, one or more pairs of relieving channels 27 and 37 are provided. Further, one or more relieving channels 27 and/or 37 can be provided independently at any position in the circumference of the respective sealing surface 25 and/or 35.

(16) FIG. 6 shows a compressor 10 with a relieving groove at maximum pressure according to another embodiment. The embodiment shown here differs from the embodiments shown in FIGS. 4 and 5 by the arrangement and the configuration of the relieving channels. The embodiment shown in FIG. 6 provides for one or more relieving channels 27 and/or 37 at the circumferential positions of the housing screws 50. The relieving channels 27 and/or 37 extend radially from the grooves 40a and 40b up to the radial position of the respective screw through-hole 32. In addition, in the housing cover 30, one or more relieving borings 38 are provided, which extend radially from the screw through-hole 32 to the environment 11 of the compressor 10. The relieving borings 38 are not disposed in the sealing surface 35 of the housing cover 30, that is in the surface of the housing cover, but entirely within the boundaries of the volume of the housing cover 30. The pressurization medium E, which escapes at maximum pressure from the pressure chamber 13 of the compressor 10, can be collected in the grooves 40a and 40b and then be discharged via the relieving channels 27 and/or 37, via respective screw through-holes 32 and relieving borings 38 into the environment 11 of the compressor 10. If this way of the pressurization medium E to be discharged shall be ensured, the part of screw through-holes 32 distal to the pressure chamber must be closed beyond the axial screw position of the relieving borings 38 in the housing cover 30 and made impermeable for the pressurization medium. In this case, the housing cover 30 includes one or more partially closed screw through-holes 33.

(17) FIG. 7A shows a radial pressure gradient in the sealing surfaces 125 and 135 between the two housing parts 20 and 30 of the typical compressor 10 at operating pressure. The sealing surface 135 of the housing cover 30 and the sealing surface 125 of the housing 20 rest on one another at the operating pressure. The radial pressure gradient in the sealing surfaces at the operating pressure G.sub.BS decreases over the entire sealing surface radially from the inside to the outside, wherein on the radially inner edge of the sealing surfaces of the full operating pressure is applied in the pressure chamber 12, and on the outer radial edge of the sealing surfaces the ambient pressure of the environment 11 is applied.

(18) FIG. 7B shows the radial pressure gradient in the sealing surface 125 and 135 between two housing parts 20 and 30 of the typical compressor 10 for maximum pressure. When the maximum pressure is applied on the pressure chamber 13 of the compressor 10, the sealing surface 135 of the housing cover 30 and the sealing surface 125 of the housing 20 diverge with an acute angle, whereby the gap 31 is formed. As a result, in a radial area of the sealing surfaces from the inner edge of the radial sealing surface 125 and 135 near to the outer edge of the sealing surfaces, the full maximum pressure is applied on pressure chamber 13 at the sealing surfaces. Only in the outer radial edge of the sealing surfaces up to the outer edge of the sealing surfaces, the radial pressure gradient G.sub.HS in the sealing surface at the maximum pressure shows an idealized linearly decreasing curve up to the environment 11 of the compressor 10 under ambient pressure.

(19) FIG. 7C shows the radial pressure gradients in the sealing surfaces 25 and 35 between two housing parts 20 and 30 of the compressor 10 according to some embodiments for the operating pressure and for the maximum pressure. In the configuration shown here, the sealing surface 25 of the housing 20 and the sealing surface 35 of the housing cover 30 have each a groove 40a and 40b, respectively extending in circumferential direction. The radial pressure gradients in the sealing surfaces at the operating pressure G.sub.BE and at the maximum pressure G.sub.HE are in contrast to the corresponding pressure gradients for the typical compressor limited radially on the range between the inner edge radial of the sealing surfaces and the radial position of the grooves 40a and 40b. Concerning the radial extension of the sealing surfaces, the ambient pressure of the environment 11 is applied to from the radial position of the grooves 40a and 40b.

(20) According to at least one of the disclosed embodiments, the maximum pressure can be predetermined by a relatively simple safety device, against which the connecting device applies a contact pressure force between the housing parts. Thus, under the same conditions, it is possible to have a connecting device with smaller dimension compared to the conventional compressors resulting in cost and space benefits.

(21) Furthermore, the axial compression force between two housing parts can be limited, the axial compression force being in relation to the longitudinal axis of the compressor, compared to conventional technology such as in DE 198 07 691 A1 where only a radial force can be avoided. This limitation of the axial compression force allows, for example, a smaller dimensioning of the connecting device between the housing parts without that inside of the compressor the contact force falls below the minimum contact pressure between the housing parts necessary to maintain the pressure chamber.

(22) In addition, the groove extending in the circumferential direction, for example, does not need to have a sealing function and that it therefore can be configured in regard to its function of a pressure reduction.

(23) While the above description has pointed out features of various embodiments, the skilled person will understand that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made without departing from the scope of the appended claims.