Scroll compressor

Abstract

[Problem] To provide a scroll compressor that not only improves scroll and discharge air cooling capacity and has improved durability but also has improved maintainability. [Solution] A scroll compressor 1 makes a mobile scroll 6 revolve around a fixed scroll 4 to compress air at compression chambers 34 that are formed between wraps 19, 32 of the scrolls. A center casing 2 rotatably supports a shaft 10 that drives the mobile scroll 6, and a cooling liquid is made to flow into the center casing 2 such that heat is exchanged between the cooling liquid and the mobile scroll 6.

Description

Scroll Compressor

[0001] The present invention relates to a scroll compressor that compresses gas such as air using a fixed scroll and a movable scroll.

[0002] Scroll-type air compressors compress air by orbiting a movable scroll against a fixed scroll, but friction and compression heat during operation cause temperatures to rise in the fixed scroll, movable scroll, bearings, oil, and discharge air, resulting in a problem of reduced durability.

[0003] Therefore, conventionally, a cooling liquid is circulated through the fixed scroll and the movable scroll to cool them, or air is blown onto the air compressor itself to cool it (see, for example, Patent Documents 1 and 2).

[0004] US2023 / 0020439A1 JP2019-73988A

[0005] However, in the configuration of Patent Document 1, the coolant is circulated through the movable scroll, so flexible piping must be connected to the movable scroll that performs the orbital movement to allow the coolant to flow, which poses durability issues. Also, in the configuration of Patent Document 2, in which air is blown onto the air compressor itself, the cooling effect is insufficient, resulting in a rise in the temperature of the scroll and compressed air.

[0006] Furthermore, in any of the configurations, it is necessary to periodically inject lubricant such as grease into the bearing portion, which presents a problem of poor maintainability.

[0007] The present invention has been made to solve the above-mentioned conventional technical problems, and aims to provide a scroll compressor that can improve the cooling capacity of the scroll and discharge gas, improve durability, and also improve maintainability.

[0008] In order to solve the above problems, the scroll compressor of the present invention compresses gas in a compression chamber formed between the wraps of a movable scroll by causing the movable scroll to revolve around a fixed scroll, and is characterized by having a casing in which a shaft that drives the movable scroll is rotatably supported, and a cooling liquid is flowed into this casing so that heat is exchanged between the cooling liquid and the movable scroll.

[0009] The scroll compressor of the invention of claim 2 is characterized in that in the above invention, a cooling path through which a cooling liquid flows is formed within the casing, and the cooling liquid flowing within this cooling path and the movable scroll exchange heat via the casing.

[0010] The scroll compressor of the invention of claim 3 is characterized in that, in the above invention, it has a heat medium sealing portion formed between the back surface of the movable scroll and the casing, and the heat medium sealed in this sealing portion exchanges heat with the coolant through the casing, and the heat medium exchanges heat with the movable scroll.

[0011] The scroll compressor of the invention of claim 4 is characterized in that in the above invention, a sealing material that slides freely against the casing is provided on the peripheral portion of the back surface of the movable scroll, and a sealing portion is formed in the space surrounded by the movable scroll, the casing, and the sealing material.

[0012] The scroll compressor of the invention of claim 5 is characterized in that in the above invention, the casing has a casing body and a casing cover provided on the movable scroll side of the casing body, and the sealing material abuts freely against the casing cover.

[0013] The scroll compressor of the invention of claim 6 is characterized in that in the above invention, a groove is formed on the surface of the casing body on the movable scroll side, the groove of the casing body is closed by a casing cover, and a cooling path is formed within this groove.

[0014] The scroll compressor of the invention of claim 7 is characterized in that in the invention of claim 3, the heat medium is oil for lubrication, and a bearing portion is disposed within the sealing portion.

[0015] The scroll compressor of the invention of claim 8 is characterized in that in the above invention, the bearing portion is any one of a coupling bearing that constitutes a mechanism for preventing rotation of the movable scroll, a drive bearing provided at the connection between the movable scroll and the shaft, and a shaft bearing provided in the casing that rotatably supports the shaft, or a combination of two of them, or all of them, and at least a portion of them is arranged within the sealing portion.

[0016] The scroll compressor of the invention of claim 9 is characterized in that, in the invention of claim 3, claim 7 or claim 8, it is provided with an agitator blade attached to the shaft and positioned within the sealing portion, and as the shaft rotates, the agitator blade agitates the oil within the sealing portion and supplies it to the bearing portion.

[0017] The scroll compressor of the invention according to claim 10 is characterized in that in the above invention, the stirring blade functions as a balance weight for canceling vibrations caused by the movable scroll undergoing orbital motion.

[0018] The scroll compressor of the invention of claim 11 is characterized in that, in the invention of claim 1, it has a cooling passage on the fixed scroll side formed on the back surface of the fixed scroll, and coolant is also circulated through this cooling passage on the fixed scroll side.

[0019] The scroll compressor of the present invention according to claim 12 is characterized in that it comprises a motor for driving the shaft, and the motor is also cooled by the coolant.

[0020] The scroll compressor of the present invention according to claim 13 is characterized in that it comprises an inverter for driving the motor, and the inverter is also cooled by the coolant.

[0021] The scroll compressor of the invention of claim 14 is characterized in that, in the invention of claim 1, it is provided with a cooling path for discharge gas through which a cooling liquid flows and which cools the gas discharged after being compressed in the compression chamber.

[0022] According to the present invention, in a scroll compressor that compresses gas in a compression chamber formed between the wraps of a movable scroll by causing the movable scroll to revolve around a fixed scroll, the compressor is provided with a casing in which a shaft that drives the movable scroll is rotatably supported, and a cooling liquid is flowed into the casing so that heat is exchanged between the cooling liquid and the movable scroll.This allows the cooling liquid to cool the movable scroll, and effectively suppresses the temperature rise of the movable scroll and the temperature rise of the compressed gas.

[0023] In particular, since the configuration does not require cooling liquid to flow through a movable scroll that performs orbital movement as in the conventional configuration, there is no need to flow cooling liquid through flexible piping, which increases the freedom of design and component selection and also enables improvements in overall durability.

[0024] Furthermore, as in the invention of claim 2, a cooling path through which a cooling liquid flows is formed within the casing, and the cooling liquid flowing within this cooling path exchanges heat with the movable scroll via the casing. This makes it possible to complete the cooling path for the cooling liquid that cools the movable scroll within the casing, thereby simplifying the structure.

[0025] In particular, as in the invention of claim 3, a sealed portion for the heat medium is formed between the back surface of the movable scroll and the casing, and the heat medium sealed in this sealed portion exchanges heat with the coolant through the casing, and also exchanges heat between the heat medium and the movable scroll, thereby making it possible to effectively cool the movable scroll via the heat medium.

[0026] In this case, as in the invention of claim 4, a sealing material that can slide freely against the casing is provided on the peripheral portion of the back surface of the movable scroll, and a sealing section is formed in the space surrounded by the movable scroll, the casing, and the sealing material.This makes it possible to effectively cool the movable scroll while forming a sealing section with a relatively simple structure, and also reduces friction between the movable scroll and the casing.

[0027] In particular, as in the invention of claim 5, by constructing the casing from a casing body and a casing cover provided on the movable scroll side of the casing body, and by making the sealing material slidably contact the casing cover, it is possible to effectively suppress friction between the movable scroll and the casing and the resulting temperature rise.

[0028] Furthermore, as in the invention of claim 6, by forming a groove on the surface of the casing body facing the movable scroll and blocking the groove in the casing body with a casing cover to form a cooling path within the groove, it is possible to form a cooling path within the casing with a simple structure.

[0029] Furthermore, as in claim 7, by sealing the seal portion with lubricating oil as the heat medium and arranging the bearing portion within this seal portion, it is possible to both cool and lubricate the movable scroll and bearing portion using the oil as the heat medium. Also, since there is no need to periodically inject grease, it is possible to improve maintainability.

[0030] Furthermore, as in the invention of claim 8, this bearing portion is a coupling bearing that constitutes a mechanism for preventing rotation of the movable scroll, or a drive bearing provided at the connection between the movable scroll and the shaft, or a shaft bearing provided in the casing to rotatably support the shaft, and at least a portion of these is arranged within the sealing portion.

[0031] Furthermore, as in the invention of claim 9, by providing an agitator blade attached to the shaft and positioned within the sealing portion, and by rotating the shaft causing the agitator blade to agitate the oil within the sealing portion and supply it to the bearing portion, it becomes possible to simplify the lubrication structure of the bearing portion while achieving uniform cooling and lubrication.

[0032] Furthermore, as in the invention of claim 10, by giving the agitator blade the function of a balance weight to cancel out the vibration caused by the orbital orbiting movement of the movable scroll, the agitator blade can also effectively suppress vibration and noise during operation.

[0033] Furthermore, as in the invention of claim 11, by providing a cooling path on the fixed scroll side configured on the back surface of the fixed scroll and circulating coolant through this cooling path on the fixed scroll side, the fixed scroll can also be effectively cooled by the coolant, thereby suppressing temperature rise and improving durability.

[0034] Furthermore, as in the inventions of claims 12 and 13, by cooling the motor that drives the shaft and the inverter that operates it with coolant, the motor and inverter can also be cooled effectively with the coolant, thereby improving durability.

[0035] Furthermore, as in the invention of claim 14, a cooling path for the discharged gas is provided to cool the gas discharged after being compressed in the compression chamber, and by circulating a cooling liquid, the temperature rise of the discharged gas can be effectively suppressed.

[0036] 1 is a longitudinal side view of a scroll compressor according to an embodiment of the present invention; FIG. 1 is a perspective view of the scroll compressor of FIG. 1; FIG. 2 is another perspective view of the scroll compressor of FIG. 1; FIG. 3 is a front view of the scroll compressor of FIG. 1; FIG. 4 is a perspective view of the scroll compressor of FIG. 1 with a rear cover removed; FIG. 5 is a front view of the scroll compressor of FIG. 1 with a rear cover removed; FIG. 6 is a perspective view of the scroll compressor of FIG. 1 with an aftercooler removed; FIG. 7 is a front view of the scroll compressor of FIG. 1 with an aftercooler removed; FIG. 8 is a perspective view of the scroll compressor of FIG. 1 with a fixed scroll removed; FIG. 9 is a perspective view of the scroll compressor of FIG. 1 with a movable scroll removed (with oil); FIG. 10 is a perspective view of the scroll compressor of FIG. 1 with a movable scroll removed (without oil); FIG. 11 is a front view of the scroll compressor of FIG. 1 with a movable scroll removed (without oil); FIG. 12 is a perspective view of the scroll compressor of FIG. 1 with a casing cover removed; FIG. 13 is a front view of the scroll compressor of FIG. 1 with a casing cover removed.

[0037] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 is a longitudinal sectional side view of a scroll compressor 1 (hereinafter referred to as compressor 1) according to an embodiment of the present invention, Figs. 2 and 3 are perspective views of compressor 1, and Fig. 4 is a front view.

[0038] The compressor 1 of the embodiment is an air compressor used to discharge compressed air (gas) to, for example, air brakes on large vehicles. As shown in FIG. 1 , the compressor 1 comprises a metal center casing 2 made of aluminum or the like, a shaft casing 15 connected to one end of the center casing 2 with bolts, a motor (electric motor) 3 connected to one end of the shaft casing 15 with bolts, a metal fixed scroll 4 connected to the other end of the center casing 2 with bolts, a metal movable scroll 6 disposed within the center casing 2 and constituting a scroll compression mechanism 5 together with the fixed scroll 4, a metal aftercooler 7 attached to the other end of the fixed scroll 4, a rear cover 8 attached to the other end of the aftercooler 7, and legs 9 attached to the bottom. The center casing 2 is an example of a casing in the present invention. The motor casing 3 houses a motor (electric motor) 64 and an inverter 66 for operating the motor 64, and also includes a connector 67 for supplying power to the inverter 66.

[0039] The center casing 2 is open on the side opposite to the motor casing 3 (the other end), and after the movable scroll 6 is accommodated in this opening, it is closed when the fixed scroll 4 is fixed to the center casing 2. A through hole 11 is formed in the center of the center casing 2, and the other end of a shaft 10 (the shaft that drives the movable scroll 6) connected to the motor shaft 68 of the motor 64 is inserted therethrough. A shaft bearing 12 is attached to the center casing 2 on the movable scroll 6 side of this through hole 11, as a bearing part that rotatably supports the shaft 10. The shaft bearing 12 rotatably supports the shaft 10 in the center casing 2.

[0040] 2 to 4, the fixed scroll 4 is formed with two air suction ports 13, and air sucked in from the air suction ports 13 is drawn to the outside of the scroll compression mechanism 5. The air compressed by this scroll compression mechanism 5 is discharged from a central discharge hole 14 into an air flow path 16 formed in a serpentine shape inside the aftercooler 7, and after passing through this air flow path 16, is finally discharged from an air discharge port 17 formed in the rear cover 8. A discharge pipe (not shown) is connected to the air discharge port 17, and the compressed air is supplied from the air discharge port 17 through the discharge pipe to the air brake described above.

[0041] The scroll compression mechanism 5 is composed of the fixed scroll 4 and the movable scroll 6. The fixed scroll 4 is integrally provided with a disk-shaped end plate 18 and a spiral wrap 19 formed of an involute shape or a curve approximating an involute shape and erected on the surface (one side) of the end plate 18, and is fixed to the center casing 2 with the surface of the end plate 18 on which the wrap 19 is erected facing the center casing 2.

[0042] The aforementioned discharge hole 14 is formed in the center of the end plate 18 of the fixed scroll 4, and this discharge hole 14 communicates with one end of the air flow path 16 in the aftercooler 7, and the other end of the air flow path 16 communicates with the aforementioned air discharge port 17. The air flow path 16 is formed in the aftercooler 7 in the shape of a groove, as shown in Figures 5 and 6, and the opening of the groove of this air flow path 16 is closed when the rear cover 8 is attached.

[0043] 7 and 8 , a cooling path 21 (cooling path on the fixed scroll 4 side) is integrally formed in the shape of a serpentine groove on the back surface of the end plate 18 of the fixed scroll 4, and the opening of the groove of this cooling path 21 is closed when the aftercooler 7 is attached. A coolant inlet port 22 is formed in the rear cover 8, and this coolant inlet port 22 passes through the aftercooler 7 and is connected to one end of the cooling path 21. In addition, a coolant outlet port 23 is formed on one side surface of the fixed scroll 4, and this coolant outlet port 23 is connected to the other end of the cooling path 21.

[0044] In addition, in Figure 4, 24 is a seal washer for preventing leakage of compressed air (discharged air) from the central bolt portion for attaching the rear cover 8, in Figure 6, 26 and 27 are O-rings for preventing compressed air discharged from the discharge hole 14 from leaking to the outside, and in Figure 8, 28 and 29 are O-rings for preventing the coolant that has flowed in from the coolant inlet port 22 from leaking to the outside, as will be described later.

[0045] On the other hand, the movable scroll 6 is a scroll that revolves around the fixed scroll 4 and includes a disk-shaped end plate 31 and a spiral wrap 32 formed of an involute shape or a curve similar to an involute and erected on the surface (one side) of the end plate 31 (FIG. 9), and a drive bearing 33 serving as a bearing is fitted in the center of the back surface (the other side) of the end plate 31 (FIG. 1). The movable scroll 6 is disposed so that the wrap 32 projects toward the fixed scroll 4, and the wraps 32 face the wraps 19 of the fixed scroll 4 and mesh with each other, forming a pressure chamber 34 between the wraps 19, 32.

[0046] That is, the wrap 32 of the movable scroll 6 faces the wrap 19 of the fixed scroll 4, and they are engaged with each other so that the tip of the wrap 32 abuts or is close to the surface of the end plate 18, and the tip of the wrap 19 abuts or is close to the surface of the end plate 31. In addition, an eccentric portion 36 provided eccentrically from the axis at the tip of the shaft 10 is fitted into the drive bearing 33 of the movable scroll 6.

[0047] Coupling bearings 37 are attached to the center casing 2 at three locations (FIGS. 10 to 12) as bearings that constitute a rotation prevention mechanism for the movable scroll 6, and each coupling bearing 37 is fitted onto the back surface of the movable scroll 6. When the shaft 10 is rotated by the motor 64, the movable scroll 6 is configured to revolve around the fixed scroll 4 without rotating on its own axis.

[0048] Because the movable scroll 6 revolves eccentrically relative to the fixed scroll 4, the eccentric direction and contact position of each wrap 19, 32 move while rotating, and as described above, the compression chamber 34 that takes in air sucked in from the air suction port 13 moves inward and gradually shrinks. As a result, the air is compressed and is finally discharged from the central discharge hole 14 into the air flow path 16 in the aftercooler 7.

[0049] The center casing 2 of the embodiment is composed of a casing body 35 and a casing cover 39, both of which are made of metal, and a cooling path 38 is formed within the center casing 2 ( FIGS. 13 and 14 ). The cooling path 38 is formed as a serpentine groove on the surface of the casing body 35 facing the movable scroll 6, and the opening of the groove is closed by the annular casing cover 39 attached to the casing body 35 facing the movable scroll 6, thereby forming the cooling path 38 within the center casing 2 ( FIGS. 1 , 9 to 12 ).

[0050] 1 , the back surface of the movable scroll 6 is recessed, and a seal 41 (also called a side seal) is attached to the peripheral edge of the back surface of the movable scroll 6 so as to surround the recessed portion. This seal 41 slidably abuts against the casing cover 39. A seal 42 that slides against the shaft 10 is attached to the through hole 11 of the center casing 2 on the motor 64 side of the shaft bearing 12, a seal 44 is also attached to the center casing 2 on the motor 64 side of the coupling bearing 37, and a seal 43 is also attached between the center casing 2 and the casing cover 39 at the peripheral edge of the center casing 2.

[0051] As a result, a sealed portion 46 is defined between the back surface of the movable scroll 6 and the casing cover 39 of the center casing 2, which is a space surrounded by the movable scroll 6, the center casing 2, and the sealing material 41. The shaft bearing 12, the coupling bearing 37, and the drive bearing 33 are positioned within this sealed portion 46, and oil (indicated by 47 in FIG. 10 ) is sealed therein as an example of a heat medium. Note that the entirety or at least part of the shaft bearing 12, the entirety or at least part of the coupling bearing 37, and the entirety or at least part of the drive bearing 33 are also disposed within the sealed portion 46. In addition, in FIG. 14 , 48 denotes an O-ring at an oil 47 inlet provided in the center casing 2, and 49 denotes an O-ring at an oil 47 outlet.

[0052] Furthermore, an agitator blade 51 is attached to the shaft 10 on the center casing 2 side of the eccentric portion 36 and is located within the sealing portion 46. This agitator blade 51 has a predetermined weight and functions as a balance weight to cancel out vibrations caused by the orbiting motion of the movable scroll 6. A balance weight 52 is also attached to the shaft 10 on the motor 64 side of the center casing 2, and similarly functions to suppress vibrations.

[0053] A coolant inlet port 56 is formed on one side surface of the center casing 2, and this coolant inlet port 56 is connected to one end of the cooling path 38. This coolant inlet port 56 is then connected in communication with the coolant outlet port 23 of the fixed scroll 4 via a predetermined pipe 57 (indicated by an arrow in FIG. 2 ).

[0054] A coolant outlet port 58 is formed on the other side of the center casing 2, and this coolant outlet port 58 is connected to the other end of the cooling path 38. A coolant inlet port 61 and a coolant outlet port 62 are formed on the other side of the motor casing 3. Each port is connected to a cooling path 69 formed as a jacket structure around the motor 64 inside the motor casing 3, and the coolant outlet port 58 of the center casing 2 is connected to the coolant inlet port 61 by a predetermined pipe 63 (indicated by an arrow in FIG. 3 ). Note that the pipe 63 and the aforementioned pipe 57 may be made of flexible pipes as in the past, but because the center casing 2 does not move due to the operation of the motor 68, conventional flexible pipes are not necessary and they can also be made of ordinary metal pipes.

[0055] Here, the coolant inlet port 22 of the rear cover 8 and the coolant outlet port 62 of the motor casing 3 are connected to a coolant circulation device (not shown). This coolant circulation device circulates coolant (e.g., water, antifreeze, coolant, etc.) using a pump (not shown) between a radiator (also not shown) and the compressor 1. That is, by operating the pump, coolant cooled in the radiator is supplied to the compressor 1 from the coolant inlet port 22, and the coolant whose temperature has risen in the compressor 1 is sucked through the coolant outlet port 62 and circulated back to the radiator.

[0056] Next, the operation of the compressor 1 of this embodiment, configured as described above, will be described. When the motor 64 is operated, the shaft 10 rotates, driving the movable scroll 6. Then, due to the action of the eccentric portion 36 and the coupling bearing 37, the movable scroll 6 revolves around the fixed scroll 4. Air is drawn into the compression chambers 34 defined between the wraps 19, 32 of the scrolls 4, 6 via the air intake ports 13, compressed inward, and discharged from the central discharge hole 14 into the air flow path 16 in the aftercooler 7.

[0057] The compressed air discharged into the air flow path 16 of the aftercooler 7 passes through the serpentine air flow path 16, is discharged from an air discharge port 17 formed in the rear cover 8, and is supplied to the air brakes described above via a discharge pipe (not shown) (as indicated by the white arrows in Figures 2 and 3).

[0058] Meanwhile, when the pump of the coolant circulation device described above is operated, the coolant cooled by the radiator described above is supplied to the compressor 1 from the coolant inlet port 22. The coolant supplied to the coolant inlet port 22 enters the cooling passage 21 formed on the back surface of the end plate 18 of the fixed scroll 4. As the coolant flows in a serpentine manner through this cooling passage 21, it absorbs heat from the fixed scroll 4 itself and cools it, and also cools the compressed air passing through the air flow passage 16 via the wall surface of the aftercooler 7.

[0059] That is, the cooling path 21 on the fixed scroll 4 side also serves as a cooling path for the discharge air (cooling path for the discharge gas in the present invention), thereby suppressing a rise in temperature of the fixed scroll 4 and also suppressing a rise in temperature of the compressed air discharged from the air discharge port 17.

[0060] The coolant that has passed through the cooling path 21 in the fixed scroll 4 flows out from the coolant outlet port 23, passes through the pipe 57, and then flows from the coolant inlet port 56 into the cooling path 38 in the center casing 2. The coolant that has flowed into this cooling path 38 cools the center casing 2 itself as it passes therethrough, and also cools the oil in the sealing portion 46 via the casing cover 39.

[0061] Here, the oil 47 sealed within the sealing portion 46 is cooled by exchanging heat with the coolant via the casing cover 39 of the center casing 2. The oil 47 also exchanges heat with the movable scroll 6 that constitutes the sealing portion 46, so that the coolant and the movable scroll 6 are in a heat exchange relationship, and the movable scroll 6 exchanges heat with the coolant via the casing cover 39 of the center casing 2 and the oil 47, and is cooled by absorbing heat from the coolant.

[0062] Furthermore, the rotation of the shaft 10 rotates the agitator blade 51 attached to it, causing the oil 47 in the seal portion 46 to be agitated and circulated by the agitator blade 51. As a result, the movable scroll 6 is evenly cooled by the oil 47. Furthermore, since the shaft bearing 12, coupling bearing 37, and drive bearing 33 are disposed within the seal portion 46 as described above, a mist of the oil 47 is supplied to these components, effectively lubricating them.

[0063] The coolant that has passed through the cooling path 38 of the center casing 2 in a serpentine manner flows out of the coolant outlet port 58 and flows through the piping 63 into the coolant inlet port 61. As it passes through the cooling path 69 inside the motor casing 3, it absorbs heat from the motor 64, cools it, and then flows out of the coolant outlet port 62, is sucked into the pump of the coolant circulation device, and is sent back to the radiator, repeating this cycle. The inverter 66 located near the motor 64 is also cooled via the wall surface of the motor casing 3 by the coolant that has flowed into the cooling path 69 from the coolant inlet port 61.

[0064] As described above in detail, in the present invention, a coolant is introduced into the center casing 2 in which the shaft 10 that drives the movable scroll 6 is rotatably supported, and heat is exchanged between the coolant and the movable scroll 6. This allows the movable scroll 6 to be cooled by the coolant, and makes it possible to effectively suppress the temperature rise of the movable scroll 6 and the temperature rise of the compressed air.

[0065] In particular, since the present invention does not have a configuration in which coolant is passed through the movable scroll 6 that performs orbital movement as in the conventional configuration, there is no need to pass the coolant through flexible piping, which increases the freedom of design and component selection and also makes it possible to improve durability overall.

[0066] In addition, in the embodiment, a cooling path 38 through which a coolant flows is formed within the center casing 2, and the coolant flowing within this cooling path 38 exchanges heat with the movable scroll 6 via the casing cover 39 of the center casing 2. This makes it possible to complete the cooling path 38 for the coolant that cools the movable scroll 6 within the center casing 2, thereby simplifying the structure.

[0067] In particular, in the embodiment, a heat medium sealing section 46 is formed between the back surface of the movable scroll 6 and the center casing 2, and the heat medium (oil in the embodiment) sealed in this sealing section 46 exchanges heat with the coolant through the casing cover 39 of the center casing 2, and by configuring the heat medium to exchange heat with the movable scroll 6, it is possible to effectively cool the movable scroll 6 via the heat medium.

[0068] In this embodiment, a sealing material 41 that can slide freely against the casing cover 39 of the center casing 2 is provided on the peripheral portion of the back surface of the movable scroll 6, and a sealing portion 46 is formed in the space surrounded by the movable scroll 6, the casing cover 39, and the sealing material 41. This makes it possible to effectively cool the movable scroll 6 while forming the sealing portion 46 with a relatively simple structure, and furthermore, to reduce friction between the movable scroll 6 and the casing cover 39.

[0069] In particular, in the embodiment, the center casing 2 is composed of a casing body 35 and a casing cover 39 provided on the movable scroll 6 side of the casing body 35, and the sealing material 41 is designed to slide freely against the casing cover 39, thereby making it possible to effectively suppress friction between the movable scroll 6 and the center casing 2 and the resulting temperature rise.

[0070] In addition, in the embodiment, a groove is formed on the surface of the casing body 35 facing the movable scroll 6, and the groove of the casing body 35 is closed by the casing cover 39 to form a cooling path 38 within the groove, so that the cooling path 38 within the center casing 2 can be formed with a simple structure.

[0071] Furthermore, in the embodiment, lubricating oil 47 is sealed inside the sealing portion 46 as a heat medium, and the bearing portion (coupling bearing 37, shaft bearing 12, drive bearing 33) is arranged inside the sealing portion 46, so that the oil, which is a heat medium, can both cool and lubricate the movable scroll 6 and the bearing portion. Also, since there is no need to periodically inject grease, maintenance can be improved.

[0072] In addition, in the embodiment, an agitator blade 51 is provided that is attached to the shaft 10 and positioned within the sealing portion 46, and as the shaft 10 rotates, the agitator blade 51 agitates the oil within the sealing portion 46 and supplies it to the bearing portion, thereby simplifying the lubrication structure of the bearing portion while enabling uniform cooling and lubrication.

[0073] Furthermore, in this embodiment, the stirring blade 51 functions as a balance weight to cancel out the vibrations caused by the orbital movement of the movable scroll 6, so that the stirring blade 51 can also effectively suppress vibrations and noise during operation.

[0074] In addition, in the embodiment, a cooling path 21 on the fixed scroll 4 side is provided on the back surface of the fixed scroll 4, and coolant is also circulated through this cooling path 21 on the fixed scroll 4 side, so that the fixed scroll 4 can also be effectively cooled by the coolant, thereby suppressing temperature rise and improving durability.

[0075] In addition, in the embodiment, the motor 64 and inverter 66 that drive the shaft 10 are also cooled by the coolant, so that the motor 64 and inverter 66 can also be effectively cooled by the coolant, thereby improving their durability.

[0076] In addition, in the embodiment, a cooling path for discharge air (a cooling path for discharge gas; in the embodiment, this is also the cooling path 21) is provided to cool the air that is discharged after being compressed in the compression chamber 34, and a cooling liquid is circulated through it, so that the temperature rise of the discharge air can also be effectively suppressed.

[0077] It goes without saying that the specific configuration of the compressor 1 described in the above embodiment is not limited to this, and various modifications are possible within the scope of the present invention.

[0078] For example, in the embodiment, a sealing portion 46 is configured to seal the heat transfer medium therein, and the movable scroll 6 is cooled by the coolant via this heat transfer medium, but the invention of claim 1 also includes, for example, a configuration in which the coolant flowing into the center casing 2 is directly directed to the sealing portion 46 (when lubrication of each bearing portion is not taken into consideration).

[0079] Furthermore, in the embodiment, oil is sealed in the sealing portion 46 as a heat transfer medium, but if lubrication of each bearing portion is not a consideration, in the inventions of claims 1 to 6, a fluid other than oil, such as water or antifreeze similar to a coolant, may be sealed.

[0080] Furthermore, in the embodiment, the cooling path 21 formed in the fixed scroll 4 is configured to also serve as a cooling path for the discharge air, but this is not limiting, and a separate cooling path (cooling path for the discharge gas) that cools the compressed air discharged from the scroll compression mechanism 5 with a coolant may be provided.

[0081] In addition, in the embodiment, all of the coupling bearing 37, the drive bearing 33, and the shaft bearing 12 are arranged in the sealed portion 46, but this is not a limitation, and any one of them, or a combination of two of them, may be arranged in the sealed portion 46. Furthermore, in the embodiment, the motor 64 and the inverter 66 are also cooled by cooling water, but this is not a limitation, and either one of them may be cooled.

[0082] Furthermore, in the embodiment, the scroll compressor 1 has been described as an air compressor that compresses and discharges air, but the object to be compressed is not limited to air, and the compressor can be applied to general gases such as (pure) nitrogen, hydrogen, and oxygen.

[0083] Furthermore, in the embodiment, the coolant flows in series through the cooling path 21 of the fixed scroll 4, the cooling path 38 of the center casing 2, and the cooling path 69 of the motor casing 3 in that order, but this is not limiting. The coolant discharged from the pump of the coolant circulation device described above and passed through the radiator may be divided and circulated through the cooling path 21 of the fixed scroll 4, the cooling path 38 of the center casing 2, and the cooling path 69 of the motor casing 3, respectively, and after passing through these paths, the water may be reunited and sucked into the pump, so that the water may flow in parallel through each cooling path.

[0084] Furthermore, in the embodiment, the coolant is circulated from the above-described coolant circulation device to the cooling path 21 of the fixed scroll 4, the cooling path 38 of the center casing 2, and the cooling path 69 of the motor casing 3, but the inventions of claims 1 to 10 are not limited to this, and the coolant may be circulated independently from separate coolant circulation devices to each of the cooling paths.

[0085] REFERENCE SIGNS LIST 1 Compressor (scroll compressor) 2 Center casing (casing) 3 Motor casing 4 Fixed scroll 6 Orbiting scroll 10 Shaft 12 Shaft bearing 19, 32 Wrap 21 Cooling path 33 Drive bearing 34 Compression chamber 35 Casing body 37 Coupling bearing 38 Cooling path 39 Casing cover 41 Seal material 46 Sealing portion 47 Oil (heat medium) 51 Agitating blade 64 Motor 66 Inverter 69 Cooling path

Claims

1. A scroll compressor that compresses gas in a compression chamber formed between the wraps of a movable scroll by causing the movable scroll to revolve around a fixed scroll, the scroll compressor comprising a casing in which a shaft that drives the movable scroll is rotatably supported, and a cooling liquid that flows into the casing and exchanges heat with the movable scroll.

2. A scroll compressor as described in claim 1, characterized in that a cooling path through which the cooling liquid flows is formed within the casing, and the cooling liquid flowing within the cooling path and the movable scroll exchange heat via the casing.

3. A scroll compressor as described in claim 2, characterized in that it is provided with a heat transfer medium sealing portion configured between the back surface of the movable scroll and the casing, and the heat transfer medium sealed in the sealing portion exchanges heat with the coolant through the casing, and the heat transfer medium exchanges heat with the movable scroll.

4. A scroll compressor as described in claim 3, characterized in that a sealing material that slides freely against the casing is provided on the peripheral portion of the back surface of the movable scroll, and the sealing portion is formed in the space surrounded by the movable scroll, the casing, and the sealing material.

5. A scroll compressor as described in claim 4, characterized in that the casing has a casing body and a casing cover provided on the movable scroll side of the casing body, and the sealing material slidably contacts the casing cover.

6. A scroll compressor as described in claim 5, characterized in that a groove is formed on the surface of the casing body facing the movable scroll, the groove of the casing body is closed by the casing cover, and the cooling path is formed within the groove.

7. A scroll compressor according to claim 3, wherein the heat medium is lubricating oil, and a bearing is disposed within the sealing portion.

8. A scroll compressor as described in claim 7, characterized in that the bearing portion is one of a coupling bearing that constitutes an anti-rotation mechanism for the movable scroll, a drive bearing provided at the connection between the movable scroll and the shaft, and a shaft bearing provided in the casing that rotatably supports the shaft, or a combination of two of them, or all of them, and at least a portion of them is arranged within the sealing portion.

9. A scroll compressor as described in claim 3, claim 7 or claim 8, characterized in that it is provided with an agitating blade attached to the shaft and positioned within the sealing portion, and when the shaft rotates, the agitating blade agitates the oil within the sealing portion and supplies it to the bearing portion.

10. A scroll compressor according to claim 9, wherein the stirring blade functions as a balance weight to counteract vibrations caused by the orbiting motion of the movable scroll.

11. A scroll compressor according to claim 1, characterized in that it is provided with a cooling passage on the fixed scroll side formed on the back surface of the fixed scroll, and the cooling liquid is also circulated through the cooling passage on the fixed scroll side.

12. The scroll compressor according to claim 1, further comprising a motor for driving the shaft, wherein the motor is also cooled by the cooling liquid.

13. The scroll compressor according to claim 12, further comprising an inverter for driving the motor, wherein the inverter is also cooled by the cooling liquid.

14. A scroll compressor according to claim 1, further comprising a cooling path for discharge gas through which the cooling liquid flows and which cools the gas discharged after being compressed in the compression chamber.

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