Fluid compression device

Abstract

The invention relates to a fluid compression device comprising: - a first fluid compression element, oriented about a first axis (A), - a drive shaft coaxial with the first axis (A), - a pin (56) offset parallel to the first axis (A), - a second fluid compression element, oriented about a second axis (B), offset parallel to the first axis (A), intended to cooperate with said first compression element in an orbital motion, - a bearing (58) carrying said second compression element and comprising an inner ring (60) driven in rotation by said drive shaft, said ring (60) having an eccentric bore (62) with respect to the second axis (B), received on said pin (56), said bore (60) and said pin (56) having an axis (C) offset parallel to the first and second axes (A, B). Abstract figure: Figure 2

Description

Title of the invention: FLUID COMPRESSION DEVICE Technical field of the invention

[0001] The invention relates to a fluid compression device, particularly for a thermoregulation circuit such as an air conditioning circuit in a motor vehicle. Technical background

[0002] In temperature control circuits, such as heating, ventilation and / or air conditioning systems, compressors are generally used to increase the pressure of a refrigerant from low to high. Roll compressors, or rolling piston compressors, and scroll compressors, or spiral compressors, are particularly well known.

[0003] Unlike traditional compressors that use pistons or screw gears to compress the refrigerant, such "roll" and "scroll" compressors use a fixed compression member and a moving compression member that is driven in an orbital motion to cooperate with the fixed compression member.

[0004] Thus, in a "roll" compressor, the fixed compression element consists of a fixed stator in the shape of a cylinder and the mobile compression element consists of a mobile cylindrical piston which is mounted to roll eccentrically in this stator.

[0005] The stator surrounds the cylindrical piston. It has a cylindrical wall, which is oriented along a first axis, on which the piston rolls, and which forms with it two compression chambers where the fluid is compressed successively.

[0006] To ensure the orbital movement of the rolling piston, the compressor includes a drive shaft, coaxial with the first axis. The piston, driven by the shaft, is eccentric and oriented along a second axis which is offset parallel to the first axis.

[0007] In a "scroll" compressor, the fixed compression element consists of a fixed spiral and the mobile compression element consists of a mobile spiral which is mounted in a circular translational manner eccentrically in the fixed spiral.

[0008] The fixed spiral is oriented along a first axis and forms compression chambers with the mobile spiral where the fluid is successively compressed.

[0009] To ensure the orbital movement of the moving spiral, the compressor includes a drive shaft coaxial with the first axis. The moving spiral is carried by a plate, driven by the shaft, which is eccentric and oriented along a second axis that is offset parallel to the first axis.

[0010] Conventionally, in each of these types of compressor, the moving compression element is mounted on a coaxial bearing, driven in its orbital motion by a pin, which is fixed to the drive shaft and oriented along the second axis. However, it has been observed that it is possible to improve the cooperation between the moving compression element and the fixed compression element by offsetting the axis of the bearing relative to that of the pin. To achieve this, a sleeve is generally interposed between the pin and an inner ring of the bearing. The sleeve has an outer surface, oriented along the second axis and received in an inner ring of the bearing, and a bore oriented along a third axis offset from the second axis, which is received on the pin.

[0011] Such a socket has the disadvantage of requiring complex machining.

[0012] There is therefore a real need for a simplified mounting of the mobile compression member on the pin. Summary of the invention

[0013] The invention satisfies this need by proposing a fluid compressor comprising an eccentric bearing replacing the assembly formed by the coaxial bearing and the eccentric bushing.

[0014] To this end, the invention proposes a fluid compression device, particularly for thermoregulation circuits, said device comprising:

[0015] - a first compression element of said fluid, oriented along a first axis (A),

[0016] - a drive shaft, coaxial with the first axis (A), said shaft carrying a pin, offset parallel to the first axis (A),

[0017] - a second compression element for said fluid, oriented along a second axis (B), offset parallel to the first axis (A), said second compression member being intended to cooperate with said first compression member according to an orbital movement,

[0018] - a bearing carrying said second compression member and comprising a ring inner intended to be driven in rotation by said drive shaft, said inner ring having a bore received on said pin, said bore and said pin having axis (C) offset parallel to the first axis (A) and the second axis (B).

[0019] Advantageously, the use of an eccentric bearing and the mounting of the inner ring of this bearing rotatably mounted directly on the pin of the shaft makes it possible to save an intermediate eccentric sleeve between the pin and the bearing.

[0020] According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention:

[0021] - the cooperation of the second compression member with the first member of compression determines fluid compression chambers separated by an interface zone between the second element and an internal wall of the first compression element.

[0022] - the interface area is movable with the second compression element,

[0023] - the bore of the inner ring is rotatably mounted on the pin of the shaft,

[0024] - the second compression member comprises a bore receiving a ring outer part of the bearing, mounted to rotate relative to the inner ring,

[0025] - the second compression element is a rolling piston and the first element of compression is a cylinder.

[0026] - the cylinder has an inlet port and a discharge port,

[0027] - said ports open into an internal wall of said cylinder,

[0028] - said ports are separated by a tab elastically retracted upon contact with said rolling piston

[0029] - the second compression member is a movable spiral-shaped volute and the The first compression element is a fixed, spiral-shaped volute in which the mobile volute is engaged.

[0030] - the device includes an inlet port opening to the outside of the fixed volute and a discharge port that opens into the center of the fixed volute,

[0031] - the movable volute is supported by a plate integral with the outer ring of the bearing,

[0032] - the plate is limited in a circular translational movement by via a plurality of pins with axes (D) parallel to the first, second and third axes (A, B, C), each receiving at least one edge of the plate as a stop,

[0033] - the bearing is a ball or roller bearing,

[0034] - said pawl extends from a distal end of said tree,

[0035] - said pawn is referred to said tree,

[0036] - said device includes an imbalance compensation element,

[0037] - said unbalance compensation member is received on said pin between an end distal to the drive shaft and said bearing.

[0038] - said unbalance compensation member comprises a weight and a hub training device which includes drilling and carries said weight

[0039] - the weight has at one of its axial ends a recess intended to receive a portion of the landing playfully,

[0040] - the weight has at one opposite end a recess intended to receive the distal end of the drive shaft. Brief description of the figures

[0041] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the course of the detailed explanatory description that follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the accompanying schematic drawings, among which:

[0042] [Fig-1] [Fig.1] is an axial cross-sectional view of a fluid compression device spiral according to the invention,

[0043] [Fig.2] [Fig.2] is an end view of a volute drive assembly mobile of a spiral compression device according to the invention,

[0044] [Fig.3] [Fig.3] is an end view of a bearing implemented in the drive assembly according to the invention,

[0045] [Fig.4] [Fig.4] is an axial cross-sectional view of a drive assembly of a movable volute of a spiral compression device according to the invention,

[0046] [Fig.5] [Fig.5] is a schematic cross-sectional view of a rolling piston compression device according to the invention. Detailed description of the invention

[0047] It should first be noted that the terms "first", "second", "third", etc., are used only to distinguish the components concerned from each other and do not imply any order or possible importance of said components.

[0048] As illustrated in [Fig. 1], the invention relates to a device 10 for compressing a fluid, particularly for a heating, ventilation and / or air conditioning system, especially for a motor vehicle. Said fluid comprises, for example, a refrigerant and a lubricating fluid. The refrigerant is composed, in particular, of a hydrofluorocarbon, such as that known as R-134a. Alternatively, it is, in particular, the fluid known as R1234yf or carbon dioxide, also known as R744.

[0049] In the illustrated embodiment, the device 10 comprises a compressor 12 for said fluid and an electric machine 14. The device 10 further comprises a housing 16 accommodating said electric machine 14 and said compressor 12. The housing 16 extends along a longitudinal axis A. The electric machine 14 includes in particular a motor 18, and a drive shaft 20 for the compressor 12 about the longitudinal axis A.

[0050] The compressor 12 is, for example, a scroll compressor. It comprises a first compression element 38 with axis A, here a fixed volute 38, and a second compression element 40, here a movable volute 40 with axis B. The fixed volute 38 is engaged in the movable volute 40, so that the volutes 38 and 40 each define a spiral housing. The movable volute 40 cooperates with the fixed volute 38 according to a The orbital motion of the spiral housings mutually defines successive fluid compression chambers separated by an interface zone between the moving volute 40 and the fixed volute 38, this interface zone being movable with the second compression element. These chambers are arranged between at least one inlet port 42 and one discharge port 44 of the compressor 12. The moving volute 40 is driven in rotation by the shaft 20 so that the fluid passes from one chamber to the other while being progressively compressed.

[0051] The compressor 12 here has several fluid inlet ports 42, preferably consisting of two suction ports, located at a periphery of the compressor 12 and in particular opening outside the fixed volute 38. The compressor 12 also has a discharge port 44, for example located in a fixed central part of the compressor 12, i.e. opening into the center of the fixed volute 38.

[0052] The inlet ports 42 allow the fluid to enter between the fixed volute 38 and mobile volute 40 to be progressively compressed while being drawn towards the central part of the compressor 12 from where it exits through the discharge port 44.

[0053] For this purpose, the movable scroll 40 has an axis of rotation B which is offset radially and parallel with respect to the longitudinal axis A. The axis of rotation B of the movable scroll 40 thus rotates around the axis of rotation A of the shaft 20. The movable scroll 40 is further mounted according to a pivot joint so as to be free in rotation around its own axis of rotation B.

[0054] The device 10 further includes an intermediate piece 46, mounted freely for rotation around the shaft 20, to guide the movable volute 40, according to the desired movement, in the fixed volute 38. The intermediate piece 46 has a plurality of pins 48 with axes D, parallel to the first and second axes A, B, and each receiving as a stop at least one edge of the movable volute 40.

[0055] Given the asymmetries brought about by the mobile volute 40, such a movement generates an unbalance phenomenon likely to cause vibrations.

[0056] To limit this phenomenon, the device 10 advantageously includes an imbalance compensation element 50, implemented in the form of a mass, the device 10 being configured so that the element 50 allows balancing of the drive of the shaft 20. Such an element 50 makes it possible, in particular, to balance the rotation of the shaft 20 during the rotation of the moving volute 40 of the compressor. This will be discussed further later in relation to a particular aspect of the invention.

[0057] The device 10 has a fluid inlet 52 in said housing 16, and a fluid outlet 54. The fluid thus enters the housing 16 through the inlet 52, at low pressure, passes axially through the motor 18 and then the compressor 12, into which it enters through the suction ports 42 and exits through the outlet port 44 to exit, at high pressure, through said outlet 54.

[0058] Conventionally, the movable volute 40 is mounted on a coaxial bearing 58, driven in its orbital movement by a pin 56, fixed to the drive shaft and oriented along the second axis B. However, it has been observed that it is possible to improve the cooperation between the movable compression member 40, which is here the movable volute 40, and the fixed compression member 38, which is here the fixed volute 38, by offsetting the axis of the bearing relative to that of the pin 56. This offset makes it possible to increase the contact pressure in the interface zone between the movable volute 40 and the fixed volute 38 and consequently the sealing between the chambers of said device.

[0059] In accordance with the invention and as illustrated in Figures 1 and 2, it is understood that the shaft 20 carries the pin 56, said pin 56 being offset parallel to the first axis A.

[0060] Preferably, the pin 56 extends from a distal end 57 of the tree 20. It can be made from material of said tree 20 or attached to it, as is the case in [Fig.1].

[0061] According to the invention, the bearing 58 carries the second compression member, here the movable volute 40. This bearing 58 comprises an inner ring 60 intended to be driven in rotation by the drive shaft 20. The inner ring 60 has an eccentric bore 62 with respect to the second axis B, which is received on said pin 56. The inner ring 60 of the bearing 58 is thus attached to the pin 56 without an intermediate part. The bore 62 and the pin 56 are oriented along an axis C, which, as the axis of the pin 56, is offset parallel to the first axis A, and, as the axis of the bore, is offset with respect to the second axis B.

[0062] As illustrated in [Fig. 3], the bearing 58 is advantageously a ball 59 or roller bearing. The inner ring 60 extends continuously between the bore 62 and a contact surface 78 for the balls 59 or rollers. It has two opposing flat faces 80, 82 connected internally by walls 84 of said bore 62 and / or externally by an edge at which said contact surface 78 is located. Said edge has a raceway for said balls 59 or rollers.

[0063] Regarding the mounting of the bearing 58, the bore 62 of the inner ring 60 is rotatably mounted on the pin 56 of the shaft 20. The movable volute 40 has a bore 64 receiving an outer ring 66 of the bearing, which is rotatably mounted relative to the inner ring 60. The movable volute 40 is more particularly supported by a plate 74 which is integral with the outer ring 66 of the bearing 58. It is this plate 74 which is limited in the circular translational movement by means of the plurality of pins 48 with axes D parallel to the first and second axes A, B and in this case also to the axis C, and which are received as abutments against at least one edge 76 of the plate 74.

[0064] Without limiting the invention, it could be applied to any other type of compression device comprising a compressor including a component of mobile compression cooperating in orbital motion with a fixed compression element.

[0065] Thus, as illustrated in [Fig.5], the compressor 12 can be a rolling piston compressor, comprising a rolling piston 40 moving in an orbital motion in a cylinder 38.

[0066] In this case, the cylinder 38, as in the previous case, has an inlet port 42 and a discharge port 44. The ports 42 and 44 open into an internal wall 69 of the cylinder 38. The ports 42, 44 are separated by a tab 67 which is elastically returned to contact with the rolling piston 40,

[0067] The piston 40 and the cylinder 44 mutually define two successive fluid compression chambers 68, 70 which are separated by an interface zone 72 between the rolling piston 40 and the cylinder 38, and arranged between the inlet port 42 and the discharge port 44. The interface zone 72 is movable with the rolling piston 40 so as to discharge the gases towards the outlet 44 of the compressor 12.

[0068] As illustrated in figures 1 and 4, the unbalance compensation member 50 is advantageously received on the pin 52 between the distal end 57 of the drive shaft 20 and the bearing 58. The unbalance compensation member 50 includes for this purpose a bore 86 which is traversed by the pin 52.

[0069] More particularly, the unbalance compensation member comprises a weight 88 and a drive hub which carries the weight 88 and has the bore 86. As can be seen in [Fig. 1], the weight has at one of its axial ends a recess 92 intended to receive with clearance a part of the bearing 58, and at an opposite end a recess 94 intended to receive the distal end of the drive shaft 20. This allows the unbalance compensation member not to substantially increase the axial dimensions of the device 10.

Claims

Demands

1. A device (10) for compressing a fluid, in particular for a thermoregulation circuit, said device (10) comprising: - a first compression member (38) of said fluid, oriented about a first axis (A), - a drive shaft (20), coaxial with the first axis (A), said shaft carrying a pin (56), offset parallel to the first axis (A), - a second compression member (40) of said fluid, oriented about a second axis (B), offset parallel to the first axis (A), said second compression member (40) being intended to cooperate with said first compression member (38) in an orbital motion, - a bearing (58) carrying said second compression member (40) and having an inner ring (60) intended to be driven in rotation by said drive shaft (20), said inner ring (60) having a bore (62) received on said pin (56),said bore (60) and said pin (56) having axis (C) offset parallel to the first axis (A) and the second axis (B).

2. Fluid compression device (10), wherein the cooperation of the second compression member (40) with the first compression member (38) determines fluid compression chambers separated by an interface zone between the second member (40) and an internal wall of the first compression member (38), said interface zone being movable with said second compression member (40).

3. Device (10) for compressing a fluid according to any one of claims 1 or 2, in which the bore (62) of the inner ring (60) is rotatably mounted on the pin (56) of the shaft (20).

4. Fluid compression device (10) according to any one of claims 1 to 3, wherein the second compression member (40) has a bore (64) receiving an outer ring (66) of the bearing (58), mounted to rotate relative to the inner ring (60),

5. Device (10) for compressing a fluid according to any one of claims 1 to 4, wherein the second compression member (40) is a rolling piston and the first compression member (38) is a cylinder.

6. Device (10) for compressing a fluid according to the preceding claim, in which the cylinder has an inlet port (42) and a discharge port (44), opening into an internal wall (69) of said cylinder, and separated by a tab (67) elastically returned to contact with said rolling piston (40).

7. Fluid compression device (10) according to any one of claims 1 to 4, wherein the second compression member (40) is a mobile spiral volute and the first compression member (38) is a fixed spiral volute in which the mobile volute is engaged.

8. Device (10) for compressing a fluid according to the preceding claim, comprising an inlet port (42) opening outside the fixed volute (38) and a discharge port (44) opening into the center of the fixed volute (38).

9. Fluid compression device (10) according to any one of claims 7 or 8, wherein the movable volute (40) is carried by a plate (74) integral with the outer ring (66) of the bearing (58), said plate (74) being limited in a circular translational movement by means of a plurality of pins (48) with axes (D) parallel to the first, second and third axes (A, B, C), each receiving as a buttress at least one edge (76) of the plate (74).

10. Fluid compression device (10) according to any one of the preceding claims, comprising an imbalance compensation member (50) which is received on said pin (56) between a distal end (57) of said drive shaft (20) and said bearing (58).

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