ELECTRIC ROLLER PISTON COMPRESSOR

Abstract

An electric rotary compressor (1) comprises a housing (10), an electric motor (15), and a compression mechanism (20) that compresses a coolant. The compression mechanism (20) has a rotating shaft (30) and an outer circumferential surface (21). The housing (10) has an inner circumferential surface (12). The electric rotary compressor (1) further comprises an outlet pressure region (2) defined between the inner circumferential surface (12) and the outer circumferential surface (21). The outlet pressure region (2) has an oil storage chamber (120), an outlet chamber (130), and a central chamber (140). A space between the oil storage chamber (120) and the central chamber (140) is constricted by a first convex section (100). A space between the central chamber (140) and the outlet chamber (130) is constricted by a second convex section (101).

Description

Background of the invention: Technical field

[0001] The present invention relates to an electric rotary piston compressor. State of the art

[0002] Japanese patent application publication JP H07-217576 is known as a prior art document disclosing a configuration of a horizontal compressor. The horizontal compressor described in publication JP H07-217576 comprises an enclosure and a compression component. The enclosure has an oil sump at its base. A separating plate faces a gas channel formed on an upper section of the compression component and is positioned at a predetermined distance from the gas channel. In this configuration, an oil separation channel is formed between the compression component and the separating plate. The oil separation channel is open at a position located away from the gas channel and higher than the maximum oil level stored in the oil sump. This configuration prevents oil from being forced up into the oil separation channel by escaping gas.

[0003] Japanese patent application publication JP H07-229497 is also known as a prior art document disclosing a configuration of a horizontal compressor. The horizontal compressor described in publication JP H07-229497 comprises an enclosure and a shielding element. The enclosure has an oil sump at its base. The shielding element is positioned to face an outlet pipe opening. The shielding element separates the oil from the gas, and even if the oil in the oil sump foams, the shielding element prevents the foaming oil from being carried upwards by the gas and flowing out of the compressor through the outlet pipe.

[0004] Japanese utility model application publication JP H01-063793 is known as a prior art document disclosing a configuration of a horizontal sealed compressor. The horizontal sealed compressor described in publication JP H01-063793 comprises an enclosure and a compression component. The compression component has a rear head. The rear head is sized such that an outer circumference of the rear head is close to an inner circumferential surface of the enclosure, thus forming a throttle channel between the rear head and the enclosure. The throttle channel prevents fluctuations in an oil surface on the opposite side of an outlet pipe, caused by the operation of a blade, from being directly transmitted to an oil surface on the outlet pipe side.

[0005] Japanese patent application publication JP H02-023294 is known as a prior art document disclosing a configuration of a horizontal rotary compressor. The horizontal rotary compressor described in publication JP H02-023294 has a sealed vessel and a separating element. The separating element is located in an outlet chamber, such that a tiny gap is formed between the separating element and an inner surface of the sealed vessel. A throttle formed on the separating element prevents the lubricating oil from foaming in the outlet chamber.

[0006] In the configurations of the compressors described in publications JP H07-217576, JP H07-229497, JP H01-063793, and JP H02-023294, when the coolant compressed in the casing comes into contact with the oil surface of the lubricating oil stored at the bottom of the casing, the oil surface tends to become unstable. When the oil surface of the lubricating oil becomes unstable, the lubricating oil, which is forced upwards by the coolant at high pressure, easily flows out of the compressor.

[0007] The present invention was made to solve the above-mentioned problems and is aimed at providing an electric rotary piston compressor in which outflow of lubricating oil from the compressor is prevented by stabilizing an oil surface of the lubricating oil. Summary of the invention

[0008] According to one aspect of the present invention, an electric rotary piston compressor is provided, comprising a housing, an electric motor housed in the housing, and / or a compression mechanism housed in the housing and arranged horizontally next to the electric motor, wherein the compression mechanism compresses a coolant mixed with lubricating oil and drawn in by operation of the electric motor, and discharges the compressed coolant. The compression mechanism has a rotating shaft driven by the electric motor and an outer circumferential surface extending circumferentially along the axis of the rotating shaft. The housing has an inner circumferential surface extending circumferentially.The electric rotary piston compressor further comprises an outlet pressure zone, defined between the inner and outer circumferential surfaces, in which the coolant and lubricating oil are present. The outlet pressure zone includes an oil reservoir chamber located vertically in the lowest part of the zone, containing a subsection of the compression mechanism; an outlet chamber located vertically in the highest part of the zone, containing an upper section of the compression mechanism; and a central chamber located circumferentially between the oil reservoir chamber and the outlet chamber, which communicates (fluidically) with both.A space between the oil storage chamber and the central chamber is narrowed by a first convex section, wherein the first convex section projects radially along the axis from one of the inner and outer circumferential surfaces towards the other, and reduces the radial distance between the inner and outer circumferential surfaces around the first convex section. A space between the central chamber and the outlet chamber is narrowed by a second convex section, wherein the second convex section projects radially along the axis from one of the inner and outer circumferential surfaces towards the other, and reduces the radial distance between the inner and outer circumferential surfaces around the second convex section.

[0009] Further aspects and advantages of the invention will become apparent from the following description, in conjunction with the accompanying drawings, which illustrate the principles of the invention by way of example. Brief description of the characters

[0010] The invention, together with its tasks and advantages, is best understood by reference to the following description of the embodiments together with the accompanying drawings, in which: Fig. 1 a cross-sectional view illustrating a configuration of an electric rotary piston compressor according to an embodiment of the present invention; Fig. 2 A perspective view showing the flow paths of a coolant and lubricating oil in the electric rotary piston compressor of Fig. 1 illustrates; Fig. 3 a cross-sectional view showing the configuration of the electric rotary compressor of Fig. Figure 1 illustrates how, seen in one direction by arrows of a line III-III, it is; and Fig. Figure 4 is a cross-sectional view illustrating a positional relationship between an outlet pressure area and an oil separator. Detailed description of preferred embodiments

[0011] An embodiment of the present invention is described below with reference to the drawings. In the following description of the embodiment, identical or substantially identical components have the same reference numerals and may not be repeated.

[0012] Note that in the drawings, a direction perpendicular to both the direction in which a rotating shaft axis extends and to a vertical direction is defined as an X-direction; the vertical direction is defined as a Y-direction; and the direction in which the rotating shaft axis extends is defined as a Z-direction. Configurations, except those necessary for explanation, and representations of connection structures between configurations or the like may be omitted from the drawings. Furthermore, in Fig. 3 and Fig. 4. Cross-sectional sections of the compressor as described are not illustrated by hatching.

[0013] First, the overall configuration of an electric rotary piston compressor is described below. Fig. Figure 1 is a cross-sectional view illustrating a configuration of an electric rotary piston compressor according to the embodiment of the present invention.

[0014] An electric rotary compressor 1 can, for example, be mounted on a vehicle. The electric rotary compressor 1 is used, for example, for air conditioning the vehicle. The electric rotary compressor 1 in the present embodiment is driven, for example, using carbon dioxide (CO2) as a refrigerant. Since the Z-direction, as the first direction, is a horizontal direction, the electric rotary compressor 1 of the present embodiment is a horizontally arranged compressor, with its width in the horizontal direction being greater than its height in the vertical direction.

[0015] As in Fig. As illustrated in Figure 1, the electric rotary piston compressor 1 in the present embodiment has a housing 10, an electric motor 15 and a compression mechanism 20.

[0016] The housing 10 defines an external form of the electric rotary piston compressor 1. The housing 10 is, for example, made of aluminum or an aluminum alloy.

[0017] The housing 10 has a suction port through which the coolant is drawn in, and which is not illustrated. The suction port extends through an inner circumferential surface near the electric motor 15 in the housing 10. The coolant is drawn into the housing 10 through the suction port.

[0018] The housing 10 has an outlet port 11 through which the coolant is / is discharged. The housing 10 has an inner circumferential surface 12. The inner circumferential surface 12 extends in a circumferential direction along an axis C of a rotating shaft 30, which extends in the first direction (Z-direction), as will be described later.

[0019] The outlet port 11 extends through the inner circumferential surface 12 near the compression mechanism 20 in the housing 10. The outlet port 11 is formed in an upper section of the housing 10 in the Y-direction. The coolant compressed by the compression mechanism 20 is discharged through the outlet port 11 onto an outer surface of the housing 10.

[0020] The electric motor 15 is housed in the casing 10. The electric motor 15 has a stator 16 and a rotor 17. The stator 16 is formed from a plurality of electromagnetic steel sheets stacked in the Z direction (not shown). The stator 16 is attached to the inner circumferential surface near the electric motor 15 in the casing 10. The rotor 17 is formed from a plurality of electromagnetic steel sheets stacked in the Z direction (not shown). The rotor 17 is arranged inside the stator 16 with a space between them.

[0021] The compression mechanism 20 is housed in the casing 10. The compression mechanism 20 is arranged horizontally (Z-direction) next to the electric motor 15. The compression mechanism 20 compresses the coolant, which is mixed with the lubricating oil and drawn in by the operation of the electric motor 15, and discharges the compressed coolant. The components forming the compression mechanism 20 are made, for example, of an aluminum alloy or an iron alloy.

[0022] The compression mechanism 20 has an outer circumferential surface 21. The outer circumferential surface 21 extends in the circumferential direction of axis C. The electric rotary piston compressor 1 has an outlet pressure zone 2. The outlet pressure zone 2 is defined between the inner circumferential surface 12 of the housing 10 and the outer circumferential surface 21 of the compression mechanism 20. The coolant and the lubricating oil are present in the outlet pressure zone 2. The compression mechanism 20 discharges the coolant, which is compressed in the outlet pressure zone 2 and mixed with the lubricating oil.

[0023] The compression mechanism 20 comprises the rotary shaft 30, a first compression part 40, a second compression part 50, a front plate 60, a cover element 61, a middle side plate 62, a rear plate 63 and a silencer 64.

[0024] The rotating shaft 30 is driven by the electric motor 15. The rotating shaft 30 has an axis C extending in the first direction (the Z-direction in the present embodiment). The rotating shaft 30 extends in the first direction (Z-direction) through the components that form the compression mechanism 20, with the exception of the rotating shaft 30. The direction in which the axis C of the rotating shaft 30 extends is not limited to the horizontal direction and can be a direction inclined to the horizontal.

[0025] The rotating shaft 30 has a fixed section 31, a shaft section 32, and eccentric shaft sections 33. The fixed section 31 is attached to an inner circumferential surface of the rotor 17. In this configuration, when the electric motor 15 is driven, the rotating shaft 30 is rotated about the axis C with rotation of the rotor 17.

[0026] The shaft section 32 is inserted through the front plate 60, the cover element 61, the middle side plate 62, the rear plate 63, the front plate 60, and the silencer 64. The eccentric shaft sections 33 are each located within a corresponding space of the first compression part 40 and the second compression part 50.

[0027] The first compression part 40 has a first piston 41, a first blade 42 and a first cylinder 43.

[0028] The first piston 41 is rotatable eccentrically to the axis C when the rotating shaft 30 rotates. The first piston 41 is engaged with one of the associated eccentric shaft sections 33 in the rotating shaft 30.

[0029] The first blade 42 and the first piston 41 are arranged in a direction intersecting with the first direction (Y-direction) and are in contact with each other. The first blade 42 is movable in the Y-direction according to the rotation of the first piston 41 while it is in contact with the first piston 41.

[0030] The first piston 41 and the first blade 42 are housed in the first cylinder 43. As it rotates eccentrically to the axis C, the first piston 41 slides on an inner circumferential surface of the first cylinder 43.

[0031] An oil channel 45 (see Fig. 3), which will be described later, is formed on the outer circumferential surface of the first cylinder 43. The oil channel 45 extends through the first cylinder 43 in the vertical direction (Y-direction) at right angles to the first direction.

[0032] A first compression chamber, in which the coolant is / is compressed, is formed between the first cylinder 43 and both the first piston 41 and the first vane 42. The coolant is / is introduced into the first compression chamber through a first intake port, which is not shown. As the first piston 41 rotates eccentrically to axis C, the volume in the first compression chamber gradually decreases, thus compressing the coolant. The compressed coolant is / is discharged through a first exhaust valve, which is not shown.

[0033] The second compression part 50 has a second piston 51, a second vane 52 and a second cylinder 53. In the second compression part 50, similar to the configuration of the first compression part 40, the second piston 51 and the second vane 52 within the second cylinder 53 are driven by the rotation of the rotary shaft 30.

[0034] A second compression chamber, in which the coolant is compressed, is formed between the second cylinder 53 and both the second piston 51 and the second vane 52. The coolant is introduced into the second compression chamber through a second intake port, which is not shown. As the second piston 51 rotates eccentrically to axis C, the volume in the second compression chamber gradually decreases, thus compressing the coolant. The compressed coolant is then discharged through a second exhaust valve 69.

[0035] The front plate 60 and the first cylinder 43 are arranged in this order in the first direction (Z-direction) and are in contact with each other. The front plate 60 and the first compression chamber are arranged side by side in this order in the first direction (Z-direction) and are in contact with each other. The shaft section 32 of the rotating shaft 30 slides on a bearing section of the front plate 60 as the rotating shaft 30 rotates.

[0036] The front plate 60 is in contact with the housing 10 on one side facing the first cylinder 43. The front plate 60 is in contact with the housing 10, so that the front plate 60 closes off the outlet pressure area 2.

[0037] The cover element 61 and the front plate 60 are arranged in this order in the first direction (Z-direction) and are in contact with each other. An outer circumferential section of the cover element 61 is positioned between two housing components of the housing 10 in the first direction (Z-direction). The cover element 61 is connected to the housing 10 at its outer circumferential section by screws (not shown). Thus, the compression mechanism 20 is attached to the housing 10.

[0038] The central side plate 62 is provided between the first cylinder 43 and the second cylinder 53 in the first direction (Z-direction) and separates the first compression chamber from the second compression chamber.

[0039] The rear plate 63 is in contact with the second cylinder 53 on the side opposite the front plate 60 in the first direction (Z-direction). The second compression chamber and the rear plate 63 are arranged side by side in the first direction (Z-direction) and are in contact with each other. The shaft section 32 of the rotating shaft 30 slides on a bearing section of the rear plate 63 as the rotating shaft 30 rotates.

[0040] The silencer 64 is in contact with the rear plate 63 on one side opposite the front plate 60 in the first direction (Z-direction). The coolant released from the second outlet valve 69 flows through an interior space of the silencer 64.

[0041] The following describes the paths of the coolant and the lubricating oil in the electric rotary piston compressor 1. Fig. Figure 2 is a perspective view showing the flow paths of the coolant and lubricating oil in the electric rotary piston compressor of Fig. 1 illustrates.

[0042] As in Fig. As illustrated in Figure 2, an outlet channel formed within the compression mechanism 20 has a first outlet channel 3, a second outlet channel 4 and a third outlet channel 5.

[0043] The first outlet channel 3 is a channel through which the coolant discharged from the first compression part 40 flows. The coolant discharged from the first compression part 40 flows from the first outlet valve through a first chamber S1 (see Fig. 1) between the front panel 60 and the cover element 61.

[0044] The second outlet channel 4 is a channel through which the coolant discharged from the second compression section 50 flows. The coolant discharged from the second compression section 50 flows from the second outlet valve 69 through a second chamber S2 (see Fig. 1) of the silencer 64. The discharged coolant flows through the second chamber S2; and then flows into the first chamber S1 through a through-hole 22 (see Fig. 1).

[0045] The third outlet channel 5 is formed from through holes extending through the components of the compression mechanism 20. The coolant flowing through the first outlet channel 3 and the coolant flowing through the second outlet channel 4 merge in the third outlet channel 5.

[0046] The electric rotary piston compressor 1 in the present embodiment further comprises an oil separator 65. The oil separator 65 separates the lubricating oil mixed with the coolant discharged from the compression mechanism 20 from the coolant. The oil separator 65 in the present embodiment is integrated with the silencer 64.

[0047] A bore / hole 66 is formed in the oil separator 65 and extends in the Y direction. The bore 66 communicates (fluid-wise) with the third outlet channel 5. The coolant mixed with the lubricating oil at high pressure is introduced into the bore 66 through the third outlet channel 5.

[0048] The bore 66 has a coolant outlet port 67 and an exhaust port 68. The coolant outlet port 67 is located on an upper section of the bore 66 in the Y-direction. The compressed coolant is discharged through the coolant outlet port 67 in the direction of the inner circumferential surface 12. The exhaust port 68 is located in a lower section of the bore 66 in the Y-direction. The lubricating oil is exhausted through the exhaust port 68.

[0049] When the coolant mixed with the lubricating oil is introduced into bore 66 of the oil separator 65, it flows through bore 66 and rotates due to the momentum of the coolant. When the coolant is discharged, the lubricating oil is separated from the coolant by centrifugal force. The coolant is discharged to an upper part in the outlet pressure area 2 through the coolant outlet port 67. The lubricating oil is exhausted to a lower part in the outlet pressure area 2 through the exhaust channel 68.

[0050] Fig. Figure 3 is a cross-sectional view showing the configuration of the electric rotary compressor of Fig. Figure 1 illustrates how to see in one direction through arrows of a line III-III.

[0051] As in Fig. As illustrated in Figure 3, an O-ring 13 is provided on an end face of the housing 10 in the Z-direction. The outlet pressure area 2 is enclosed by the O-ring 13.

[0052] The outlet pressure area 2 extends over its entire circumference in the circumferential direction of axis C. The outlet pressure area 2 has an oil storage chamber 120, an outlet chamber 130, and a central chamber 140.

[0053] The oil reservoir chamber 120 is located in the lowest part of the outlet pressure area 2 in the vertical direction. A subsection of the compression mechanism 20 is located in the oil reservoir chamber 120. The oil reservoir chamber 120 is the area where the lubricating oil is present. The oil reservoir chamber 120 communicates (fluid-wise) with the oil channel 45 of the first compression part 40. The lubricating oil is supplied from the oil reservoir chamber 120 to an inner surface of the first cylinder 43 via the oil channel 45. The lubricating oil is also supplied from the oil reservoir chamber 120 to an inner surface of the second cylinder 53 via an oil channel formed in the second cylinder 53, which is not shown.

[0054] In the present embodiment, the first cylinder 43 and the second cylinder 53 each have a downward-extending section. In these configurations, the outer circumferential surfaces of the first cylinder 43 and the second cylinder 53 are easily immersed in the lubricating oil, compared to a case where the respective cross-section of the first cylinder 43 and the second cylinder 53 is circular.

[0055] The outlet chamber 130 is located in the uppermost part of the outlet pressure region 2 in the vertical direction. An upper section of the compression mechanism 20 is located in the outlet chamber 130. The outlet chamber 130 is the region where the coolant is mainly located. In the present embodiment, the outlet chamber 130 occupies essentially the upper half of the outlet pressure region 2.

[0056] The central chamber 140 is defined between the oil storage chamber 120 and the outlet chamber 130 in a circumferential direction of the compression mechanism 20. The central chamber 140 is a region in which the coolant and the lubricating oil are present. The central chamber 140 communicates (fluidically) with the oil storage chamber 120 and the outlet chamber 130.

[0057] The central chamber 140 is formed on opposite sides of the oil storage chamber 120 and on opposite sides of the outlet chamber 130 in the circumferential direction of the compression mechanism 20. In the present embodiment, the central chamber 140 has a first central chamber 141 and a second central chamber 142. The first central chamber 141 is formed between the oil storage chamber 120 and the outlet chamber 130 on one side in the X-direction. The second central chamber 142 is formed between the oil storage chamber 120 and the outlet chamber 130 on the other side in the X-direction.

[0058] The volume in the outlet chamber 130 is larger than that in the middle chamber 140. In the present embodiment, the volume in the outlet chamber 130 is larger than the combined volume of the first middle chamber 141 and the second middle chamber 142.

[0059] The volume of the central chamber 140 is larger than that of the oil storage chamber 120. In the present embodiment, the volume in each of the first central chamber 141 and the second central chamber 142 is larger than that in the oil storage chamber 120.

[0060] First convex sections 100 are formed between the oil storage chamber 120 and the central chamber 140. In the present embodiment, a pair of the first convex sections 100 is formed on the left and right sides of the axis C in the X direction.

[0061] The first convex sections 100 project radially along axis C from one of the inner circumferential surfaces 12 of the housing 10 and the outer circumferential surface 21 of the compression mechanism 20 towards the other. In the present embodiment, the first convex sections 100 project radially along axis C from the inner circumferential surface 12 of the housing 10 towards the outer circumferential surface 21 of the compression mechanism 20.

[0062] Each of the first convex sections 100 reduces the distance around the first convex section 100 between the inner circumferential surface 12 and the outer circumferential surface 21 in the radial direction of axis C. As a result, a space between the oil storage chamber 120 and the central chamber 140 is narrowed by each of the first convex sections 100. First throttling channels 150, through which the oil storage chamber 120 is connected to the central chamber 140, are formed between the inner circumferential surface 12 and the outer circumferential surface 21 around the associated first convex sections 100.

[0063] Second convex sections 101 are formed between the central chamber 140 and the outlet chamber 130. In the present embodiment, a pair of the second convex sections 101 is formed on the left and right sides of axis C in the X direction.

[0064] The second convex sections 101 project radially from / out of one of the inner circumferential surfaces 12 of the housing 10 and the outer circumferential surface 21 of the compression mechanism 20 towards the other. In the present embodiment, the second convex sections 101 project radially from / out of the inner circumferential surface 12 towards the outer circumferential surface 21.

[0065] Each of the second convex sections 101 reduces the distance around the second convex section 101 between the inner circumferential surface 12 and the outer circumferential surface 21 in the radial direction of axis C. Consequently, a space between the central chamber 140 and the outlet chamber 130 is narrowed by each of the second convex sections 101. Second throttle channels 151, through which the central chamber 140 is connected to the outlet chamber 130, are formed between the inner circumferential surface 12 and the outer circumferential surface 21 around the associated second convex sections 101.

[0066] The first convex sections 100 and the second convex sections 101 are formed in the inner circumferential surface 12. The first convex sections 100 and the second convex sections 101 are each formed by making a shape of the inner circumferential surface 12 itself convex. Note that the first convex sections 100 and the second convex sections 101 can be formed by attaching elements, each with a convex shape, to the inner circumferential surface 12 as separate elements for configuring the first and second convex sections.

[0067] Third convex sections 102 project in the radial direction of axis C from / out of the inner circumferential surface 12 towards the outer circumferential surface 21 in the outlet chamber 130. In the present embodiment, a pair of the third convex sections 102 is formed on the left and right sides of axis C in the X direction.

[0068] The outlet port 11 is positioned between the pair of third convex sections 102 in the circumferential direction. Since the third convex sections 102 are formed on opposite sides of the outlet port 11 in the circumferential direction, a flow of coolant encounters one of the third convex sections 102 and is / is split into two flows, and one of the two split flows is / is blocked by the other of the third convex sections 102, so that the coolant flows easily into the outlet port 11.

[0069] Note that the present invention can have a configuration in which the first convex sections are formed in the housing 10 and the second convex sections are formed in the compression mechanism 20. Furthermore, the present invention can have a configuration in which the first convex sections 100, the second convex sections 101, and the third convex sections 102 project to be inclined relative to the radial direction, in addition to the configuration in which the first convex sections 100, the second convex sections 101, and the third convex sections 102 project radially.

[0070] A shortest radial distance between each of the first convex sections 100 and one of the inner circumferential surfaces 12 and the outer circumferential surface 21 facing the first convex section 100 is defined as a first distance. In the present embodiment, a shortest radial distance between each of the first convex sections 100 and the outer circumferential surface 21 is defined as a first distance D1. Additionally, a shortest radial distance between each of the second convex sections 101 and one of the inner circumferential surfaces 12 and the outer circumferential surface 21 facing the second convex section 101 is defined as a second distance. In the present embodiment, a shortest radial distance between each of the second convex sections 101 and the outer circumferential surface 21 is defined as a second distance D2. Here, the first distance D1 is shorter than the second distance D2.

[0071] Fig. Figure 4 is a cross-sectional view illustrating the positional relationship between the outlet pressure area and the oil separator. Fig. Figure 4 only illustrates bore 66 in the oil separator 65.

[0072] As in Fig. As illustrated in Figure 4, the bore 66 of the oil separator 65 in the outlet pressure area 2 is located such that it extends along the Y direction.

[0073] The compressed coolant is discharged towards the inner circumferential surface 12 through the coolant outlet port 67 of the oil separator 65. The compressed coolant is discharged towards one of the third convex sections 102 through the coolant outlet port 67. When the discharged coolant encounters one of the third convex sections 102, the coolant flow is split into a first flow F1 and a second flow F2 in the circumferential direction.

[0074] The first stream, F1, extends upwards beyond the third convex section 102 in the Y direction. Since the coolant is lighter than the lubricating oil, the coolant constitutes a larger proportion in the first stream, F1. The second stream, F2, extends downwards below the third convex section 102 in the Y direction. Since the lubricating oil is heavier than the coolant, the lubricating oil constitutes a larger proportion in the second stream, F2. Consequently, even if the coolant discharged through the coolant outlet port 67 is mixed with the lubricating oil, the coolant and the lubricating oil remain separate.

[0075] The exhaust channel 68 of the oil separator 65 (fluid-)communicates with the central chamber 140. This makes it difficult for the pressure of the lubricating oil exhausted through the exhaust channel 68 to affect the oil surface of the lubricating oil in the oil storage chamber 120. The lubricating oil is exhausted in the Z-direction along the axis C through the exhaust channel 68. Thus, since the oil storage chamber 120 and the central chamber 140 are defined in the circumferential direction of the first direction (Z-direction) along the axis C, the lubricating oil exhausted through the exhaust channel 68 hardly comes into contact with the oil surface of the lubricating oil in the oil storage chamber 120, which stabilizes the oil surface of the lubricating oil in the oil storage chamber 120.

[0076] In the electric rotary piston compressor 1 according to the embodiment of the present invention, the outlet pressure area 2 formed between the housing 10 and the compression mechanism 20 is partitioned / divided into the outlet chamber 130, the central chamber 140, and the oil storage chamber 120, each of which is connected to the adjacent chamber; and the first convex sections 100 and the second convex sections 101 are formed in the circumferential direction of the axis C, so that the space between the two adjacent chambers is narrowed. In this configuration, the flow velocity of the discharged coolant in the outlet chamber 130, the central chamber 140, and the oil storage chamber 120 is fast, medium, and slow, respectively. This stabilizes the oil surface of the lubricating oil in the oil storage chamber 120, thus preventing the lubricating oil from flowing out of the electric rotary piston compressor 1.

[0077] In the electric rotary piston compressor 1 according to the embodiment of the present invention, the volume in the outlet chamber 130 is larger than that in the central chamber 140, so that the influence of outlet pressure pulsation caused by the compressed coolant is reduced in the outlet pressure range 2. Since the volume in the central chamber 140 is larger than that in the oil reservoir chamber 120, the oil channel 45 in the oil reservoir chamber 120 is easily immersed in the lubricating oil. In this configuration, the lubricating oil is continuously supplied to the compression mechanism 20.

[0078] In the electric rotary piston compressor 1 according to the embodiment of the present invention, the first distance D1 in each of the first throttle channels 150 is shorter than the second distance D2 in each of the second throttle channels 151. This makes the cross-sectional area in each of the first throttle channels 150 communicating with the oil storage chamber 120 smaller than the cross-sectional area in each of the second throttle channels 151, so that the influence of the coolant pressure discharged to the outlet pressure area 2 at a position in the outlet pressure area 2 that is closer to the oil storage chamber 120 is further reduced. This stabilizes the oil surface of the lubricating oil in the oil storage chamber 120.

[0079] In the electric rotary piston compressor 1 according to the embodiment of the present invention, the central chamber 140 is formed on opposite sides of the oil storage chamber 120 and on opposite sides of the outlet chamber 130. This increases the number of supply points from which the lubricating oil is fed to the oil storage chamber 120, so that the lubricating oil is easily returned to the oil storage chamber 120.

[0080] In the electric rotary piston compressor 1 according to the embodiment of the present invention, the compression mechanism 20 can be made mainly of an iron alloy; and the housing 10 can be made of an aluminum alloy. The first convex sections 100 and the second convex sections 101 are formed in the housing 10, which is made mainly of aluminum, which is lighter than iron. In this configuration, the first convex sections 100 and the second convex sections 101 are made mainly of aluminum, so the compressor is lighter compared to a case where the first convex sections 100 and the second convex sections 101 are made mainly of iron.Furthermore, the shape of the outer circumferential surface 21 of the compression mechanism 20 is simplified by forming the first convex sections 100 and the second convex sections 101 in the housing 10, so that the other of the two flows, which arises when the flow of lubricating oil meets one of the third convex section 102 and is split in the outlet pressure area 2, easily goes from the outlet chamber 130 towards the oil storage chamber 120.

[0081] In the electric rotary piston compressor 1 according to the embodiment of the present invention, the exhaust channel 68 communicates (fluid-) with the central chamber 140. This prevents the lubricating oil from coming into contact with the oil surface of the lubricating oil in the oil storage chamber 120 at high pressure, thus stabilizing the oil surface of the lubricating oil in the oil storage chamber 120.

[0082] In the electric rotary piston compressor 1 according to the embodiment of the present invention, even if the lubricating oil remains in the coolant due to oil separation in the oil separator 65, since the coolant is discharged in the direction of one of the third convex section 102 through the coolant outlet port 67, the lubricating oil is efficiently separated from the coolant by collision separation.

[0083] Note that the electric rotary compressor according to the present invention can have a two-stage compression mechanism in which the coolant compressed by the first compression part is fed to the second compression part and further compressed by the second compression part. Furthermore, the electric rotary compressor in the present invention can be formed from a single compression part comprising a piston, a vane, and a cylinder. If the electric rotary compressor is formed from a single compression part, the central side plate is not required. [Additional notes]

[0084] This embodiment incorporates the following inventions. [Configuration 1]

[0085] An electric rotary piston compressor with: a case; an electric motor that is housed in the casing; and a compression mechanism which is housed in the casing and arranged next to the electric motor in a horizontal direction, wherein the compression mechanism compresses a coolant mixed with lubricating oil and drawn in by operation of the electric motor and releases the compressed coolant, the compression mechanism features: a rotating shaft driven by the electric motor; and an outer circumferential surface that extends in a circumferential direction along an axis of the rotating shaft; wherein the housing has an inner circumferential surface extending in the circumferential direction; and wherein the electric rotary piston compressor further comprises an outlet pressure area defined between the inner circumferential surface and the outer circumferential surface, in which the coolant and the lubricating oil are present; characterized by the fact that - the outlet pressure range is: an oil storage chamber located in a lower part in the outlet pressure area in a vertical direction and containing a subsection of the compression mechanism; an outlet chamber located in the highest part of the outlet pressure range in the vertical direction, and in which an upper section of the compression mechanism is located; and a central chamber located circumferentially between the oil storage chamber and the outlet chamber, and communicating with the oil storage chamber and the outlet chamber; - a space between the oil storage chamber and the central chamber is narrowed by a first convex section, wherein the first convex section projects in a radial direction of the axis from one of the inner and outer circumferential surfaces towards the other of the inner and outer circumferential surfaces and reduces a distance around the first convex section between the inner and outer circumferential surfaces in the radial direction; and - a space between the middle chamber and the outlet chamber is narrowed by a second convex section, wherein the second convex section projects in the radial direction of the axis from one of the inner circumferential surface and the outer circumferential surface towards the other of the inner circumferential surface and the outer circumferential surface and reduces a distance around the second convex section between the inner circumferential surface and the outer circumferential surface in the radial direction. [Configuration 2]

[0086] The electric rotary piston compressor according to configuration 1, characterized in that a volume in the outlet chamber is larger than a volume in the central chamber; and the volume in the central chamber is larger than a volume in the oil storage chamber. [Configuration 3]

[0087] The electric rotary piston compressor according to configuration 1 or 2, characterized in that a shortest distance in the radial direction between the first convex section and the other of the inner circumferential surface and the outer circumferential surface facing the first convex section is defined as a first distance; a shortest distance in the radial direction between the second convex section and the other of the inner circumferential surface and the outer circumferential surface facing the second convex section is defined as a second distance; and the first distance is shorter than the second distance. [Configuration 4]

[0088] The electric rotary piston compressor according to one of the configurations 1 to 3, characterized in that the outlet pressure area extends over an entire circumference of the outlet pressure area in the circumferential direction; and the central chamber is formed on opposite sides of the oil storage chamber and on opposite sides of the outlet chamber in the circumferential direction. [Configuration 5]

[0089] The electric rotary piston compressor according to one of the configurations 1 to 4, characterized in that the first convex section and the second convex section are formed in the inner circumferential surface. [Configuration 6]

[0090] The electric rotary piston compressor according to one of configurations 1 to 5, further comprising: an oil separator arranged to separate the lubricating oil mixed with the coolant discharged from the compression mechanism, characterized in that the oil separator has an exhaust channel through which the lubricating oil is exhausted; and the exhaust channel communicates (fluid-) with the central chamber. [Configuration 7]

[0091] The electric rotary piston compressor according to one of configurations 1 to 5, further comprising: an oil separator arranged to separate the lubricating oil mixed with the coolant discharged from the compression mechanism from the coolant, characterized in that the oil separator has a coolant outlet port through which the compressed coolant is discharged in the direction of the inner circumferential surface; a third convex section projects radially from the inner circumferential surface in the direction of the outer circumferential surface in the outlet chamber; and the coolant is discharged in the direction of the third convex section through the coolant outlet port.

[0092] It should be noted that the embodiment disclosed herein and described above is in every respect merely an example and is not intended to serve as a basis for a restrictive interpretation. Accordingly, the scope of the present invention is not limited to the embodiment described above. Furthermore, the scope of the present invention includes all modifications within the meaning and scope of the claims and their equivalents. In the description of the embodiment described above, such combinable configurations may be combined with one another. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP H07-217576 [0002, 0006] JP H07-229497 [0003, 0006] JP H01-063793 [0004, 0006] JP H02-023294 [0005, 0006]

Claims

[1] Electric rotary piston compressor (1) with: a case (10); an electric motor (15) which is housed in the casing (10); and a compression mechanism (20) which is received in the housing (10) and arranged next to the electric motor (15) in a horizontal direction, wherein the compression mechanism (20) compresses a coolant mixed with lubricating oil and drawn in by operation of the electric motor (15) and releases the compressed coolant, wherein the compression mechanism (20) comprises: a rotating shaft (30) driven by the electric motor (15); and an outer circumferential surface (21) which extends in a circumferential direction of an axis (C) of the rotating shaft (30); wherein the housing (10) has an inner circumferential surface (12) extending in the circumferential direction; and wherein the electric rotary piston compressor (1) further comprises an outlet pressure area (2) defined between the inner circumferential surface (12) and the outer circumferential surface (21) in which the coolant and the lubricating oil are present; characterized by , that - the outlet pressure range (2) exhibits: an oil storage chamber (120) which is located in a lower part in the outlet pressure area (2) in a vertical direction and in which a subsection of the compression mechanism (20) is located; an outlet chamber (130) located in a highest part of the outlet pressure area (2) in the vertical direction and in which an upper section of the compression mechanism (20) is located; and a central chamber (140) located in the circumferential direction between the oil storage chamber (120) and the outlet chamber (130) and communicating with the oil storage chamber (120) and the outlet chamber (130); - a space between the oil storage chamber (120) and the central chamber (140) is narrowed by a first convex section (100), wherein the first convex section (100) projects in a radial direction of the axis (C) from one of the inner circumferential surfaces (12) and the outer circumferential surface (21) towards the other of the inner circumferential surface (12) and the outer circumferential surface (21) and reduces a distance around the first convex section (100) between the inner circumferential surface (12) and the outer circumferential surface (21) in the radial direction; and - a space between the central chamber (140) and the outlet chamber (130) is narrowed by a second convex section (101), wherein the second convex section (101) projects in the radial direction of the axis (C) from one of the inner circumferential surface (12) and the outer circumferential surface (21) towards the other of the inner circumferential surface (12) and the outer circumferential surface (21) and reduces a distance around the second convex section (101) between the inner circumferential surface (12) and the outer circumferential surface (21) in the radial direction. [2] Electric rotary piston compressor (1) according to claim 1, characterized by , that a volume in the outlet chamber (130) is larger than a volume in the middle chamber (140); and the volume in the middle chamber (140) is larger than the volume in the oil storage chamber (120). [3] Electric rotary piston compressor (1) according to claim 1 or 2, characterized by , that a shortest distance in the radial direction between the first convex section (100) and the other of the inner circumferential surface (12) and the outer circumferential surface (21) facing the first convex section (100) is defined as a first distance (D1); a shortest distance in the radial direction between the second convex section (101) and the other inner circumferential surface (12) and the outer circumferential surface (21), which faces the second convex section (101), is defined as a second distance (D2); and the first distance (D1) is shorter than the second distance (D2). [4] Electric rotary piston compressor (1) according to any one of claims 1 to 3, characterized by , that the outlet pressure area (2) extends over the entire circumference of the outlet pressure area (2) in the circumferential direction, and the central chamber (140) is formed on opposite sides of the oil storage chamber (120) and on opposite sides of the outlet chamber (130) in the circumferential direction. [5] Electric rotary piston compressor (1) according to any one of claims 1 to 4, characterized by , that the first convex section (100) and the second convex section (101) are formed in the inner circumferential surface (12). [6] Electric rotary piston compressor (1) according to any one of claims 1 to 5, further comprising: an oil separator (65) which is designed to separate the lubricating oil mixed with the coolant discharged from the compression mechanism (20) from the coolant, characterized by , that the oil separator (65) has an exhaust channel (68) through which the lubricating oil is exhausted; and the exhaust channel (68) communicates with the central chamber (140). [7] Electric rotary piston compressor (1) according to any one of claims 1 to 5, further comprising: an oil separator (65) which is designed to separate the lubricating oil mixed with the coolant discharged from the compression mechanism (20) from the coolant, characterized by , that the oil separator has a coolant outlet port (67) through which the compressed coolant is discharged in the direction of the inner circumferential surface (12); a third convex section (102) projects radially from the inner circumferential surface (12) towards the outer circumferential surface (21) in the outlet chamber (130); and the coolant is released in the direction of the third convex section (102) through the coolant outlet port (67).

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