JP4699501B2 - Positive displacement compressor - Google Patents

Description

  The present invention relates to a positive displacement compressor, and in particular, oil returning means that separates oil injected into a compression chamber that compresses a working fluid from an oil storage section that stores oil and returns it to the oil storage section again after being compressed. It is related with the positive displacement compressor provided with.

  In positive displacement compressors used in refrigeration cycles such as air conditioners, water heaters, refrigerators, dehumidifiers, etc., they were stored in the oil storage section to improve the sealing performance of the compression chamber and the lubricity between the elements forming the compression chamber. It is known to inject oil into the compression chamber and to separate the oil from the compressed working fluid and return it to the oil storage section again by the oil return means.

  As a specific configuration of the oil return means, for example, it is known to use a float valve structure as described in Patent Document 1 (FIGS. 2, 3 and the like). That is, the float valve structure floats on the separated oil stored in the return oil chamber maintained at the discharge pressure of the working fluid, and the needle valve interlocks with the movement of the float based on the fluctuation of the oil surface height of the separated oil. It opens and closes the communication port with the oil storage section maintained at a pressure lower than the discharge pressure of the working fluid.

JP-A-8-42469

  By the way, downsizing of the oil return means is desired as one of the means corresponding to the demand for downsizing of the positive displacement compressor. In the positive displacement compressor of Patent Document 1, the oil return means should be downsized. There is still room for improvement.

  That is, in Patent Document 1, since the sharpened surface of the needle valve faces the oil storage portion whose pressure is lower than the discharge pressure and the opposite flat surface faces the oil return chamber of the discharge pressure, the needle valve returns to the oil storage portion. Although a differential pressure due to the pressure difference between the oil chambers is applied, the communication port is opened by pulling the needle valve away in the direction opposite to the direction in which the differential pressure works.

  Therefore, in order to open the communication port, a buoyancy of the float for pulling away the needle valve with a force larger than at least this differential pressure is required. In order to obtain a greater buoyancy in the high pressure region where the working fluid is discharged, it is necessary to increase the volume of the float, which makes it difficult to reduce the size of the oil return means.

  Such a problem is caused by the difference between the discharge pressure of the working fluid and the oil storage section pressure, for example, when an operating range including a high discharge pressure is required or in a so-called low pressure chamber where the oil storage section pressure becomes the suction pressure. As the value increases, it becomes more prominent.

  Accordingly, an object of the present invention is to realize downsizing of the oil return means regardless of the differential pressure between the discharge pressure of the working fluid of the positive displacement compressor and the oil storage section pressure.

  The positive displacement compressor of the present invention includes a compression chamber constituting portion that constitutes a compression chamber that compresses a working fluid, an oil storage portion that stores oil to be supplied to the compression chamber, and a working fluid that is compressed and discharged in the compression chamber. An oil separation means for separating oil, an oil return means for returning the separated oil separated by the oil separation means to the oil storage section, a compression chamber component, an oil storage section, an oil separation means, and a casing containing the oil return means Is provided as a basic configuration. The oil return means includes an oil return chamber for temporarily storing the separated oil introduced from the oil separation means through the oil communication path, a float for floating on the oil separated in the oil return chamber, and vertical movement of the float. A float valve portion that opens and closes the communication port with the oil storage portion formed on the inner wall surface of the oil return chamber is interlocked, and the oil storage portion is held at a lower pressure than the oil return chamber.

  And in order to solve the said subject, while a float valve part covers and closes a communicating port, it moves along the inner wall surface in which the communicating port of the oil return chamber was formed with the up-and-down movement of the float, and a communicating port is made. A space that is configured to open and close, and that communicates with a space facing one end surface in the moving direction of the float valve portion and a space facing the other end surface, is characterized in that

  That is, the oil return means of the positive displacement compressor according to the present invention does not separate the float valve part in the direction opposite to the direction in which the differential pressure between the discharge pressure of the working fluid and the oil storage part works, for example, the direction in which the differential pressure works The communication port can be opened by moving the float valve portion in a direction orthogonal to the direction. In addition, since the spaces facing both end surfaces in the moving direction of the float valve portion are communicated, the pressure applied to both end surfaces in the moving direction of the float valve portion is equalized. Therefore, since the influence of the differential pressure between the discharge pressure of the working fluid and the oil storage portion when the communication port is opened is suppressed, a float with a smaller volume can be used. As a result, the oil return means can be downsized regardless of the differential pressure between the discharge pressure of the working fluid and the oil storage part.

  More specifically, a columnar float valve hole forming a part of the oil return chamber is formed at the bottom of the oil return chamber, and a communication port between the oil return chamber and the oil storage portion is formed on the side wall surface of the float valve hole. At the same time, the float valve portion can be formed in a columnar shape having a side wall surface facing the side wall surface of the float valve hole via a seal gap and movable along the column axis direction as the float moves up and down. In this case, the oil return chamber equalizing the float valve lower space formed by the side wall surface of the float valve hole, the bottom wall surface of the float valve hole, and the lower end surface of the float valve portion and the storage space for the separated oil in the oil return chamber. In addition to forming a pressure path, an upstream oil return path is formed that communicates the separated oil storage space in the oil return chamber and the communication port by rising the float.

  In this case, the oil return chamber pressure equalizing path and the upstream oil return path can be formed as separate flow paths independent of each other. For example, the upstream oil return passage is formed by a flow path penetrating the inside of the float valve portion, and one end opening of this flow path is communicated with the separated oil storage space in the oil return chamber, and the other end opening is floated to the float. Thus, it can be formed so as to communicate with the communication port between the oil return chamber and the oil storage part.

  According to this, the pressure in the upstream oil return passage changes somewhat with the communication between the upstream oil return passage and the oil storage section, but this effect is not transmitted to the oil return chamber pressure equalization passage. Therefore, the pressure in the lower space of the float valve always coincides with the pressure in the storage space for the separated oil in the return oil chamber, and the differential pressure acting on the float valve portion is suppressed.

  According to the present invention, the oil return means can be downsized regardless of the differential pressure between the discharge pressure of the working fluid of the positive displacement compressor and the oil storage section pressure.

  Hereinafter, an embodiment of a positive displacement compressor to which the present invention is applied will be described. In the following description, the same functional parts are denoted by the same reference numerals, and redundant description is omitted. Further, the present invention is not limited to the following embodiments, but includes making the embodiments more effective by appropriately combining the embodiments as necessary.

(First embodiment)
The positive displacement compressor of the first embodiment will be described with reference to FIGS. In the present embodiment, an example in which a scroll compressor is used as a positive displacement compressor is shown. The scroll compressor of this embodiment is provided with an oil storage part in the casing, and the inside of the casing becomes the suction pressure. As a case where such a so-called low pressure chamber type in which the inside of the casing has a suction pressure is adopted, there is a case where a combustible gas is used as a working fluid. For example, hydrocarbon fluids such as propane and butane correspond to this.

  This is an effective means for reducing the total amount of working fluid enclosed in the entire apparatus including the compressor from the viewpoint of safety. That is, this low pressure chamber makes it possible to reduce the number of high pressure parts in the compressor, thereby reducing the amount of working fluid. Furthermore, the working fluid that dissolves in the oil is reduced by the pressure drop in the oil storage section, and the amount of working fluid in the entire apparatus can be further reduced. Also, in the case of a working fluid used in a high pressure region such as carbon dioxide, a low pressure chamber type is used for the safety of the casing.

  First, the overall configuration and operation of the scroll compressor of the present embodiment will be schematically described, and the oil return means that is a characteristic part of the present embodiment will be described in detail thereafter.

  The overall configuration, function, and operation of the scroll compressor 1 of this embodiment will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a scroll compressor according to the first embodiment, FIG. 2 is an enlarged view of a fuel pump (FIG. 1M), FIG. 3 is an enlarged view of the vicinity of a back pressure chamber (FIG. 1N), and FIG. FIG. 5 is a detailed enlarged view of the oil separation oil return chamber (part P in FIG. 1), and FIG. 5 is a cross-sectional view of the oil separation oil return chamber (FF sectional view of FIG. 4).

  The scroll compressor 1 of the present embodiment includes, as main components, a compression chamber constituent unit 10 that constitutes a compression chamber 100 that compresses a working fluid, an oil storage unit 125 that stores oil to be supplied to the compression chamber 100, and a compression unit. An oil separation means including an oil separation chamber 90 for separating oil from the working fluid compressed and discharged in the chamber 100 and a return oil chamber 95 for returning the separated oil separated by the oil separation means to the oil storage section. An oil means, and a casing 8 containing a compression chamber constituent part, an oil storage part, an oil separation means, and an oil return means are provided.

  A suction pipe 53 is fixedly disposed on the side surface of the casing 8, and a working fluid having a suction pressure is introduced into the casing 8. Then, the working fluid is guided to the compression chamber 100 formed between the fixed scroll 2 and the orbiting scroll 3 by the suction port 2 e opened on the side surface of the fixed scroll 2. The compression chamber 100 is reduced in volume while being moved from the outer peripheral portion to the inner peripheral portion by the orbiting motion of the orbiting scroll 3, so that the compressing operation of the working fluid occurs. Thus, the orbiting scroll 3 and the fixed scroll 2 serve as the compression chamber constituting unit 10.

  Here, the orbiting motion of the orbiting scroll 3 is realized by rotating the crankshaft 6 connected to the orbiting scroll 3 by the motor 7 and preventing the Oldham ring 5 from rotating. By the way, the fixed scroll 2 is provided with a bypass valve 22 and a discharge port 2d for avoiding over-compression and liquid compression on the upper surface, and is screwed to the frame 4. Under the present circumstances, the back pressure chamber 110 of the intermediate pressure (henceforth a back pressure) shown in detail in FIG. 3 is formed between the back surface of the turning scroll 3 and the frame 4.

  The crankshaft 6 is supported at its upper part by a main bearing 24 and at its lower part by a secondary bearing 25, and an eccentric pin part 6 a at the upper end is inserted into the orbiting bearing 23 of the orbiting scroll 3. To these bearings, the oil pumped up by the oil pump 30 from the oil reservoir 125 at the lower part of the casing 8 is supplied through the oil hole 6 b of the crankshaft 6. The oil supplied to the slewing bearing 23 and the main bearing 24 enters the back pressure chamber 110, and then flows out to the side surface of the frame 4 through the back pressure chamber outflow passage 135 that penetrates the frame 4. Return to 125.

  Here, a back pressure control valve 26 is provided in the middle of the back pressure chamber outflow passage 135 to keep the pressure in the back pressure chamber 110 at a desired back pressure. By this back pressure, the orbiting scroll 3 is urged toward the fixed scroll 2 during compression. On the other hand, in order to improve the sealing performance of the compression chamber 100, oil is supplied from the slewing bearing chamber 115 to the compression chamber 100 through the compression chamber oil supply passage 130. This oil becomes discharged oil and is discharged to the upper part of the fixed scroll 2 from the discharge port 2d and the bypass valve 22 together with the working fluid.

  By the way, as shown in FIG. 2, the oil supply pump 30 is an internal gear type pump comprising an inner rotor 30a, an outer rotor 30b, a pump cylinder 30c, and a base plate 30d, and an end plate portion on the upper side surface of the inner rotor 30a. 30a1 is provided. Since the end plate portion 30a1 is pressed against the upper side surface of the outer rotor 30b by utilizing the downward force received by the crankshaft 6 by back pressure, there is an effect of suppressing leakage inside the pump.

  Further, since the inner rotor 30a is attached to the crankshaft 6 with the elastic seal 30k made of an elastic body interposed therebetween, the inner rotor 30a and the outer rotor 30b can be connected to the base plate even if the crankshaft 6 and the base plate 30d deviate from the orthogonal relationship. It becomes possible to press well to 30d, and there is an effect of suppressing leakage inside the pump.

  In addition, since the one-piece contact can be relaxed, one-side wear and deformation of both the rotors 30a, 30b and the base plate 30d can be avoided, and the reliability of the oil supply pump 30 can be improved. As the elastic seal 30k, a silicon rubber sheet, a disc spring, or the like can be considered. Further, when the formed gap rotates following the crankshaft 6 and the gap does not change with time when viewed from the crankshaft 6, a plastic elastic seal 30k such as a copper packing may be used.

  At the upper part of the fixed scroll 2, a discharge chamber 120 is formed by screwing the discharge oil separating and returning oil cylinder 55, and a discharge pipe 52 that further protrudes to the upper part of the discharge chamber 120 is mounted after the elements as described later are mounted. The discharge cover 51 is screwed to form an oil separation chamber 90 and an oil return chamber 95.

  For this reason, the working fluid and the discharge oil discharged to the upper part of the fixed scroll 2 described above flow into the discharge chamber 120. Thereafter, as shown in FIGS. 4 and 5, the air flows from the discharge expansion chamber 90 a through the discharge communication hole 90 b to the upper part of the internal space of the discharge oil separation oil return cylinder 55, and the blowout path 90 c in the direction along the inner wall surface of the oil separation chamber 90. Then, the oil is discharged into the oil separation chamber 90. As a result, the working fluid swirls in the oil separation chamber 90 and flows downward while centrifuging the discharge oil mixed in the working fluid, and is provided inside the separation ring 90d disposed in the center of the oil separation chamber 90. It is discharged out of the compressor from the discharge pipe.

  On the other hand, the discharged oil mixed in the working fluid adheres to the inner wall surface of the oil separation chamber 90, moves downward along the wall surface due to the viscous force and gravity received from the working fluid, and is a cone that is the bottom surface of the oil separation chamber 90. It reaches the bottom surface 90e. Since this bottom surface has a conical shape, the oil collects at the center of the bottom surface, is guided to the oil communication passage 75 by the inclined bottom groove 90f, and has an oil return chamber 95 having a bottom surface at a position lower than the oil separation chamber 90. Flows into the lower part.

  Here, if the blowing path 90c has the same width, the processing becomes easy and the manufacturing cost is reduced. Further, the blowing path 90c may be inclined slightly downward rather than horizontally. As a result, the working fluid that has made a round along the inner wall surface of the oil separation chamber 90 flows into the lower portion of the working fluid that newly flows into the oil separation chamber 90 from the blowing channel 90 c, and thus newly flows into the oil separation chamber 90. Merge with the working fluid can be suppressed.

  In this way, since the flow line of the working fluid draws a spiral, the working fluid whose oil content is reduced by the centrifugal separation action is not mixed with the working fluid having a high oil content, and the oil separation efficiency can be improved. There is. Moreover, since the disturbance of the flow due to the merging can be reduced and the turning speed can be kept high, there is an effect that the oil separation efficiency can be improved.

  This is the end of the schematic description of the configuration and operation other than the oil return means, which is a characteristic part of the present embodiment. Next, the oil return means will be described in detail with reference to FIGS. 6 to 10.

  First, a detailed enlarged view of the entire oil return means (FIG. 1Q part) in FIG. 6, an enlarged sectional view of the oil return chamber (FIG. 6S part) in FIG. 7, and a detail of the float valve part (FIG. 7V part) in FIG. The configuration of the oil return means will be described using an enlarged view.

  In the oil return chamber 95, a float valve body 70ab in which a float 70a that is movable in the vertical direction and a columnar float valve portion 70b fixedly disposed below the float 70a is integrated into the oil return chamber 95 (oil return chamber). In the following, the oil accumulated in the oil is floating in the oil return chamber staying oil 95b). Here, the float valve part 70b is fixedly arranged integrally with the float 70a by an upper connection part 70b6. This may be screw fixing or adhesive fixing. Moreover, when the float 70a is resin and the float valve part 70b is a metal, you may insert-mold.

  Further, as shown in FIG. 7, the float 70a is configured such that the float lower body 70a1 and the float upper body 70a2 which are fixedly arranged on the lower surface of the float valve part 70b are fixedly adhered and fixed by adhesion, welding, etc. A float hollow portion 70a3 is formed inside. As a result, the float valve body 70ab can float on the oil return chamber staying oil 95b.

  Further, the bottom surface of the oil return chamber 95 is formed with a columnar float valve hole 70c that forms a part of the oil return chamber 95 and into which the float valve portion 70b is inserted. In addition, a communication port between the oil return chamber 95 and the oil storage portion 125 is formed in the side wall surface of the float valve hole 70c through the float oil return passage 80a. The float oil return path 80a is connected to the fixed oil return path 80b and the frame oil return path 80c, and forms a downstream fixed oil return path 80abc (see FIG. 6) that uses the internal space of the casing 8 that is the suction pressure as an outlet.

  On the other hand, the float valve portion 70b is provided with lateral holes penetrating laterally at the upper and lower portions (upper valve portion lateral hole 70b1 and lower valve portion lateral hole 70b3), and further, a valve portion vertical hole 70b2 connecting them is formed at the center of the valve portion. Provided. And the valve part circumference | surroundings groove | channel 70b4 is provided in both opening parts of the lower valve part side hole 70b3. Here, the valve portion vertical hole 70b2 is formed by filling a vertical hole opened from below with a vertical hole plug 70b5. A valve portion oil return passage 70b1234 (see FIG. 8) is formed by connecting the holes that open to the float valve portion 70b from the upper valve portion lateral hole 70b1 to the valve portion peripheral groove 70b4.

  The float valve part 70b provided with such an oil passage is inserted into the float valve hole 70c. As a result, a valve portion lower space 78 is formed below the float valve portion 70b by the side wall surface of the float valve hole 70c, the bottom wall surface of the float valve hole 70c, and the lower end surface of the float valve portion 70b. This is because the float valve portion 70b has a side wall surface opposed to the side wall surface of the float valve hole 70c via a seal gap, and is formed in a column shape that can move along the column axis direction as the float 70a moves up and down. Therefore, it can be formed.

  And this valve part lower space 78 and the oil return chamber 95 are connected by the oil return chamber equalization hole 70d. Further, the valve oil return path 70b1234 and the downstream fixed oil return path 80abc become a single oil return path 80 due to the floating of the float valve body 70ab. Therefore, the valve oil return path 70b1234 is an upstream oil return path 80x, It can be seen that the downstream fixed oil return path 80abc plays the role of the downstream oil return path 80y. For this reason, in the description of the operation to be described later, both oil return paths are referred to as an upstream oil return path 80x and a downstream oil return path 80y.

  This is the end of the description of the configuration of the oil return chamber 95 and the float valve 70 as the oil return means. Next, the operation of the oil return means will be described with reference to FIGS. 9, 10A, and 10B. This will be described with reference to the enlarged sectional view of FIG.

  First, an initial state in which there is no return oil staying oil 95b or a small amount will be described with reference to FIG. In this case, as shown in FIG. 9, the lower end portion of the float valve portion 70b is attached to the bottom of the float valve hole 70c. At this time, the upstream oil return passage opening 80x1 that is the outlet of the upstream oil return passage 80x and the downstream oil return passage opening 80y1 that is the inlet of the downstream oil return passage 80y do not match in height. The communication cross-sectional area is zero. That is, the oil return path 80 is closed by the float valve 70. The downstream oil return passage opening 80y1 serves as a communication port between the oil return chamber 95 and the oil storage portion 125.

  Next, the case where oil begins to flow into the oil return chamber 95 will be described with reference to FIG. Since the float valve 70 is closed, oil tends to accumulate in the oil return chamber 95. However, since the oil return chamber equalizing hole 70d is open on the bottom surface of the oil return chamber 95, the valve portion is first passed through this hole. The oil return chamber staying oil 95b flows into the lower space 78, and the valve portion lower space 78 is filled with the oil return chamber staying oil 95b. Thus, the valve lower space 78 is always equal to the pressure (discharge pressure) of the oil return chamber 95 immediately after the compressor is operated.

  Similarly, since the float valve 70 is closed thereafter, the oil level of the return oil retaining oil 95b rises by the amount of oil flowing into the return oil chamber 95. As a result, the volume in which the float valve body 70ab is immersed in the oil return chamber staying oil 95b increases. Thereby, the buoyancy, which is a float upward force, increases, and when the float valve body 70ab is immersed to a certain oil level height, the float valve body 70ab starts to float. Next, the oil level height will be described in detail.

First, in the oil return means using this type of float valve, the force generally applied to the float valve body 70ab will be described by taking as an example the case of using a needle valve as in Patent Document 1 mentioned in the background art. . In this case, since the sharpened surface of the needle faces the oil storage part whose pressure is lower than the discharge pressure and the flat surface on the opposite side faces the oil return chamber of the discharge pressure, the needle has a space between the oil storage part and the oil return chamber. A force is applied from the flat surface side to the sharp surface side due to the pressure difference. When the area of the needle hole into which the needle is inserted is S, the differential pressure resulting from this differential pressure is
Differential pressure = S x (oil return chamber pressure-oil storage section pressure) (1)
It becomes. Since the oil return chamber pressure is the discharge pressure, the equation (1) is
Differential pressure = S x (Discharge pressure-Oil storage section pressure) (2)
It becomes.

As described above, in order to open the float valve, it is necessary to generate an upward force due to the buoyancy that exceeds the necessary force for the float valve opening operation including this differential pressure as well as the self-gravity due to the weight of the float floating part. That means
Float valve opening force required (≡ self-gravity + differential pressure) <upward force (3)
Must be established. That means
Downward force = self-gravity + differential pressure ································ (4)
Upward force = Buoyancy ··················································· (5)
It becomes. Therefore, in order for the float valve body 70ab to start rising, from the relationship of the expression (3),
Self gravity + differential pressure <buoyancy ································ (6)
The relationship must be established. Among these, the differential pressure is a force generated because the float valve portion 70b becomes a seal portion between the oil return chamber 95 that is the discharge pressure and the oil storage portion 125 that is lower than the discharge pressure.

More specifically, this differential pressure is generated when there is a pressure difference between the upper part and the lower part of the float valve part. In the present embodiment, since the float valve portion 70b has a columnar shape, the lower valve portion lower space 78 can be cut off from the oil storage portion 125, and is always in communication with the oil return chamber 95 through the oil return chamber equalizing hole 70d. Therefore, the pressure in the valve portion lower space 78 is always equal to the pressure (discharge pressure) in the oil return chamber 95. That is, the space (valve portion lower space 78) facing one end surface in the moving direction (vertical direction) of the float valve portion 70b and the space facing the other end surface (internal space of the oil return chamber 95) communicate with each other. As a result, the differential pressure does not act on the float valve body 70ab, and the downward force applied to the float valve body 70ab is only gravity. From the above, from equation (6), the float valve body 70ab starts to float.
Self gravity <buoyancy ……………………………………………………………………………………………… (6)
It can be seen that is true. Since the buoyancy is determined by the depth at which the float valve body 70ab is immersed in oil, the depth of the minimum float valve body that satisfies the expression (6) ′ is determined. The oil level at that time is indicated by a two-dot chain line in FIG.

  In this way, the float valve 70 can be opened with a buoyancy sufficient to exceed its own gravity, and the float 70a can be greatly reduced in size. As a result, there is an effect that the float valve 70 can be greatly downsized. Further, since the self-gravity is constant regardless of the operating conditions, the buoyancy required for the opening operation of the float valve 70 is constant regardless of the operating conditions.

  For this reason, since it becomes possible to reliably return the separated oil from the discharged working fluid to the oil storage section 125 under any operating conditions, there is an effect that the oil return operation can be realized with certainty. Thus, even in the case of a compressor that handles a working fluid having a very high operating pressure level such as carbon dioxide, the oil return operation can be reliably performed by the compact float valve.

  By the way, in order to reduce the size of the float valve, it is necessary to hold even if the right side of the equation (3) is small. Therefore, the left side of (3) needs to be made small. Need to do. Of these, self-gravity can be dealt with by reducing the weight of the floating part of the float valve, but the differential pressure can be considered to reduce S (cross-sectional area of the needle hole) as can be seen from equation (2). However, if this S is made too small, the flow resistance of the oil return passage increases and it becomes difficult for the discharged oil to return. As a result, when there is a large amount of separated oil, the discharged oil overflows from the oil return chamber, and the compressor The problem of discharging from the outside to the outside can occur.

  As apparent from the equation (2), this problem becomes more serious as the difference between the discharge pressure of the compressor and the oil storage section pressure increases. For example, there is a case where an operation range including a high discharge pressure is required, or a so-called low pressure chamber in which the oil storage section pressure becomes the suction pressure.

  Therefore, as a conventional measure to solve this problem, there is a means to counteract the increase in the differential pressure as an upward force acting on the needle after increasing S and increasing the buoyancy acting on the float according to the principle of the lever. It is done. However, in this case, a mechanism that realizes the mechanism of the lever is required, and the number of components increases, and a sliding part that is a rotating pair is generated, resulting in a problem of increased cost and reduced reliability. . In addition, a space for storing the lever mechanism is required, and there is a problem that the oil return means is enlarged. Furthermore, the float floating amount with respect to the needle rising amount must be increased at a rate equivalent to the rate of increase in force, and there may be a problem that the oil return chamber becomes large in order to secure the float floating amount. .

  In order to deal with such a problem, in this embodiment, the buoyancy required for the opening operation of the float valve 70 becomes very small, so that a buoyancy increasing mechanism such as an insulator is not necessary, and the float valve portion 70b is formed on the lower surface of the float 70a. The float valve body 70ab can be simply fixed. For this reason, the number of components can be reduced, and there is an effect of cost reduction. Further, there is no need to provide a sliding portion such as a rotating pair, and there is an effect that reliability is improved. In addition, there is no need for a space for storing the buoyancy increasing mechanism, and the float valve 70 can be further downsized. Further, with the downsizing of the float 70a, including the downsizing, there is an effect of reducing the weight. Further, since the floating amount of the float 70a becomes equal to the rising amount of the float valve portion 70b, the floating amount of the float 70a can be smaller than that in the case of using an insulator. For this reason, there is also an effect that the vertical dimension of the oil return chamber 95 in which the float 70a moves up and down can be reduced.

  Next, the operation of the float valve after the return oil chamber staying oil 95b has accumulated up to the two-dot chain line in FIG. 9 will be described with reference to FIGS. 10A and 10B. As described above, since the gravity of the float valve body 70ab balances with the buoyancy, the float valve body 70ab floats while keeping the depth immersed in the oil constant as the oil level rises. When the float valve body 70ab floats up to a position where the upstream oil return path opening 80x1 of the float valve body 70ab overlaps (communicates with) the downstream oil return path opening 80y1, the oil return chamber staying oil 95b is The upstream oil return path 80x and the downstream oil return path 80y communicate with each other to form the oil return path 80.

  As a result, the float valve 70 is opened, and the return oil staying oil 95b starts to flow out from the return oil chamber 95. While the floating amount of the float valve body 70ab is small, the communication cross-sectional area of both the return oil passages 80x and 80y is small, so the amount of oil flowing out from the oil return chamber 95 is small, and the oil level of the oil return chamber staying oil 95b is Continue to rise. However, as the oil level rises, the float 70a rises and the float valve portion 70b fixed thereto also rises, so that the communication cross-sectional areas of both return oil passages 80x and 80y increase.

  Therefore, the amount of oil spilled from the oil return chamber 95 increases, and the rising speed of the oil level decreases. Finally, as shown in FIG. 10A, the float valve body 70ab stops rising at a position where a communication cross-sectional area having an outflow speed equal to the inflow speed into the oil return chamber 95 is realized, and a steady state is obtained.

  When the oil inflow rate is reduced as compared with the case of FIG. 10A, the float valve body 70 ab is lower than that of FIG. On the other hand, when the oil inflow rate is increased as compared with the case of FIG. 10A, the oil return passage 80 is in a steady state where the communication cross-sectional area is larger than that of FIG. 10A, and the float valve body 70ab is higher than that of FIG. .

  As described above, in this embodiment, the float valve portion 70b covers the communication port (downstream oil return passage opening 80y1) between the oil return chamber 95 and the oil storage unit 125 to close the communication port, and the upper and lower portions of the float 70a. Along with the movement, the oil return chamber 95 is configured to move along the inner wall surface where the communication port is formed to open and close the communication port.

  FIG. 10B shows a case where the float valve body 70ab is most raised, and at this time, the center heights of the upstream oil return passage opening 80x1 and the downstream oil return passage opening 80y1 coincide with each other. Thereby, the communication cross-sectional area of the oil return path 80 monotonously increases as the float valve body 70ab rises. Assuming that this relationship does not hold, consider a configuration in which the float valve body 70ab can be raised to more than FIG. 10B.

  That is, a case is considered where the communication cross-sectional area of the oil return passage 80 decreases conversely when the float valve body 70ab rises. The amount of oil flowing into the oil return chamber 95 is very large, and the center height of the upstream oil return passage opening 80x1 and the downstream oil return passage opening 80y1 coincides to maximize the communication cross-sectional area of the oil return passage 80. Even in this case, when the oil level does not stop rising, the float valve body 70ab moves up to a position where it can be raised. As a result, the communication cross-sectional area of the oil return passage 80 decreases, the oil outflow speed from the oil return passage 80 decreases below the maximum outflow speed, and the oil discharged out of the compressor 1 increases conversely. Occurs.

  In addition, after the float valve body 70ab has been lifted up, the oil return amount that can flow through the oil return passage 80 is originally (when the communication cross-sectional area of the oil return passage 80 becomes maximum as shown in FIG. 10B). Even if it returns, there also arises a problem that it cannot flow and the amount of discharged oil increases. In the present embodiment, the communication cross-sectional area of the oil return passage 80 does not decrease as the float valve body 70ab rises, and always increases monotonously. Therefore, the above problem does not occur, and the discharge oil amount is reduced. There is an effect that it can be reduced.

  With the above configuration and operation, an abnormal increase in the oil level in the oil return chamber 95 can be avoided, so that there is an effect that backflow of oil into the oil separation chamber 90 can be avoided and mixing into the discharged working fluid can be suppressed. In addition, since oil can be reliably returned to the oil storage unit 125, it is possible to avoid running out of the oil in the oil storage unit 125 and reliably perform oil supply to the bearing and the compression chamber. Therefore, there is an effect that the reliability and high performance of the compressor 1 can be ensured. Further, since the oil level in the oil return chamber 95 can be secured at all times, it is possible to prevent the working fluid at the discharge pressure from passing through the working fluid conduction path 85 and the oil return path 80 and blowing into the casing inner space at the suction pressure. Thereby, there is also an effect of avoiding the deterioration of the compressor performance due to the short circuit in the compressor of the flow of the working fluid.

  By the way, since the float valve part 70b slides with the float valve hole 70c, it is made of a material that can withstand sliding. As an example of this, a metal material is suitable. For example, if it is made of aluminum, the specific gravity is small in the metal and can contribute to the miniaturization of the float 70a. Another example is plastic. For example, nylon or polyethylene terephthalate used as a sliding material is suitable, and these have a significantly lower specific gravity than metal and can further reduce the size of the float 70a. However, these coefficients of thermal expansion are large compared to the metal that is the material of the float valve hole 70c. Therefore, in order to keep the seal gap between the valve body and the valve hole properly, it is adopted only in places where no extreme temperature change occurs.

  Further, as shown in FIG. 7, the float 70a is provided with a float pressure equalizing passage 70a5 that communicates the float hollow portion 70a3 with the oil return chamber working fluid region 95a that is an outer region thereof. As a result, since there is no pressure difference between the inside and outside of the float, the pressure resistance design of the float 70a becomes unnecessary, and the float 70a can be manufactured with a material having a small specific gravity such as resin.

  As a result, the float 70a can be significantly reduced in size, and the oil return means can be made more compact. Further, since the float pressure equalizing path 70a5 is provided with the float outer opening 70a6 which is the upper end of the float 70a at the top of the float 70a, the possibility of oil entering from the float pressure equalizing path 70a5 to the float hollow part 70a3 is low. The float operation can be reliably realized over a long period of time.

  On the other hand, the float inner opening 70a7, which is the lower end of the float pressure equalizing passage 70a5, is a mortar-like shape that is the bottom surface of the float hollow portion 70a3 by the float pressure equalizing pipe 70a4 extending from the float upper body 70a2 to the float hollow portion 70a3. It is provided near the bottom surface 70a8.

  As a result, even if oil enters the float hollow portion 70a3 from the float pressure equalizing passage 70a5 and accumulates over the lower end of the float pressure equalizing pipe 70a4, the oil is simultaneously mixed with the working fluid in the breathing operation due to fluctuations in the discharge pressure. As shown in FIG. 7, the infiltrated oil is reduced to the height of the float inner opening 70a7.

  Oil in the float 70a can be kept below the height of the float inner opening 70a7 by the oil discharge operation utilizing such discharge pressure fluctuation, so that the upward force of the float 70a is not reduced and the float operation is continued. There is an effect that can be done.

  In addition, since the working fluid communication passage 85 that connects the upper portion of the oil separation chamber 90 and the upper portion of the oil return chamber 95 (oil return chamber working fluid region 95a), which is a working fluid region, is provided (see FIG. 4), the oil return chamber 95 and the pressure of the oil separation chamber 90 are always equal, and there is no difference between the oil level in the oil return chamber 95 and the oil level in the oil separation chamber 90. Therefore, as shown in FIG. 7, the oil return chamber staying oil 95b is stably held at a substantially constant height, and therefore, there is a risk of oil entering from the float pressure equalizing passage 70a5 that opens to the working fluid region of the oil return chamber. The nature becomes low. Therefore, there is an effect that the float operation can be surely realized over a long period of time.

  Further, the seal portion of the float valve 70 in the present embodiment is constituted by the outer peripheral surface of the float valve portion 70b and the inner peripheral surface which is the side surface of the float valve hole 70c. . For this reason, there is an extremely low risk that the seal portion is damaged, and there is an effect that a highly reliable float valve 70 can be realized. Further, since the force required for the opening / closing operation is not affected by the cross-sectional area of the valve oil return passage 70b1234 (upstream oil return passage 80x), the valve oil return passage 70b1234 (upstream oil return passage 80x) is reduced in order to reduce pressure loss. The cross-sectional area of can be enlarged as much as possible.

  As a result, even when the amount of separated oil is large, oil can be reliably returned to the oil storage section 125, and the opening and closing operation of the valve is reliably performed. For this reason, there exists an effect that an oil return means with high operation reliability is realizable.

  Further, the flow passage cross-sectional areas of the oil return chamber pressure equalizing hole 70d and the oil return passage 80 are adjusted so that the flow passage resistance of the oil return pressure equalizing hole 70d is larger than that of the oil return passage 80 during the float valve operation. Has been. Thereby, it plays the role of a damper with respect to the vertical movement of the float valve body 70ab. As a result, since the vertical movement of the float valve body 70ab can be suppressed, the resonance of the float valve body 70ab due to the vibration of the compressor can be suppressed and the breakage of the float valve 70 can be avoided. There is an effect that can be improved.

  Further, the oil return chamber equalizing hole 70d is a separate flow path from the oil return path 80. For this reason, the pressure in the valve oil return path 70b1234 is increased with the opening between the valve oil return path 70b1234 (upstream oil return path 80x) and the float oil return path 80a (downstream oil return path 80y). Although slightly changing, this influence is not transmitted to the oil return chamber equalizing hole 70d. Therefore, the pressure in the valve lower space 78 always matches the pressure in the oil return chamber 95, and the differential pressure acting on the float valve body 70ab is always zero. As a result, the float valve 70 can be made compact by reducing the size of the float 70a.

  Further, the communicating portion of the upstream oil return passage 80x and the downstream oil return passage 80y whose opening degree changes as the float valve body 70ab moves up and down serves as a throttle portion of the oil return passage 80. For this reason, when oil flows from the high pressure side (approximately equal to the discharge pressure) on the upstream oil return path 80x side to the low pressure side (approximately equal to the suction pressure) on the downstream oil return path 80y side, A phenomenon (foaming phenomenon) occurs in which a component such as a working fluid dissolved in the oil is instantaneously generated as a high-pressure gas.

  For this reason, the opening side of the downstream oil return passage 80y on the inner peripheral surface of the float valve hole 70c has a higher pressure than the surroundings, and the float valve portion 70b has a downstream oil return passage 80y on the inner peripheral surface of the float valve hole 70c. A horizontal force from the opening side to the opposite opening side is received. As described above, since the throttle portion of the oil return passage 80 is formed on the side surface of the float valve portion 70b, no vertical force is generated due to the foaming phenomenon, and the up and down operation of the float valve 70 is not disturbed. There is an effect that a reliable operation of the valve 70 is realized.

(Second Embodiment)
Next, the scroll compressor of 2nd Embodiment of this invention is demonstrated using FIG. FIG. 11 is an enlarged vertical sectional view of a float valve body in the scroll compressor according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in the following points, and the other points are the same as those in the first embodiment.

  In the second embodiment, when the oil return chamber staying oil 95b is small and the float valve body 70ab does not float, the float lower end portion 70a9 of the float 70a is inserted into the chamfered upper corner portion 70c1 of the float valve hole 70c. Is the seal part. As a result, when the oil return chamber staying oil 95b is absent or small, the float valve is reliably closed, so that the oil can be quickly stored in the oil return chamber 95, and the oil return of the discharge pressure working fluid There is an effect that it is possible to suppress the occurrence of a working fluid short-circuit flow that blows through the passage 80 into the casing space of the suction pressure.

(Third embodiment)
Next, the scroll compressor of 3rd Embodiment of this invention is demonstrated using FIG. FIG. 12 is an enlarged vertical sectional view of a float valve body in the scroll compressor according to the third embodiment of the present invention. The third embodiment is different from the first or second embodiment in the following points, and the other points are the same as those in the first or second embodiment. .

  In the third embodiment, a float lower integrated valve body 70ab1 in which a float lower body and a float valve portion 70b are integrated is used. The float outermost peripheral surface 70ab2 forming the guide rail mechanism extends vertically.

  From the viewpoint of reducing the self-gravity, it is desirable to reduce the weight as much as possible, and engineering plastics such as nylon and polyethylene terephthalate which are hard, slidable and heat resistant are suitable. As the metal material, an aluminum alloy or the like is suitable. From the viewpoint of wear resistance, stainless steel or the like is preferable. And the oil return inner peripheral surface 95c and the float valve hole 70c which are the side surfaces of the oil return chamber 95 are processed with a coaxial degree, and the diameter of the oil return inner peripheral surface 95c is slightly larger than the outermost diameter of the float. Dimension.

  On the other hand, since the float valve portion 70b and the float lower body are integrated, the coaxiality of the float outermost surface 70ab2 which is the side surface of the float valve portion 70b and the float valve body 70ab can be remarkably increased. As a result, when the float valve body 70ab is mounted in the oil return chamber 95, the float valve body 70ab is allowed to move in the vertical direction between the float outermost peripheral surface 70ab2 and the oil return inner peripheral surface 95c, and in the horizontal direction. The movement is restricted, and the inclination angle can also be defined. Here, the regulation of the inclination angle is realized by increasing the axial length of the float outermost peripheral surface 70ab2 together with the radial gap.

  As a result, since the float outermost peripheral surface 70ab2 and the oil return inner peripheral surface 95c serve as a guide rail mechanism, strong sliding contact between the float float valve portion 70b and the float valve hole 70c forming a seal gap can be avoided. As a result, wear of the valve part that causes smooth vertical movement and expansion of the seal gap can be avoided, so that there is an effect that improvement in operational reliability and reliability of the oil return means can be realized.

(Fourth embodiment)
Next, the scroll compressor of 4th Embodiment of this invention is demonstrated using FIG. FIG. 13 is an enlarged longitudinal sectional view of a float valve body in the scroll compressor according to the fourth embodiment of the present invention. The fourth embodiment is different from the third embodiment in the points described below, and the other points are the same as those in the third embodiment, and therefore, redundant description is omitted.

  In the fourth embodiment, a compressed float spring 70e is provided between the float valve element 70ab and the discharge cover 51 disposed on the upper part thereof. Even if the float valve body 70ab is displaced downward for some reason, the float valve body 70ab is prevented from being moved downward by extreme force due to the restoring force due to the buoyancy from the oil return chamber staying oil 95b. Without the float spring 70e, no restoring force is applied to the float valve body 70ab, and there is a risk of breakage of the float valve body 70ab due to a collision with the discharge cover 51.

  On the other hand, in the present embodiment, even if the float valve body 70ab is displaced upward for some reason, the compressed float spring 70e gives a restoring force, so that the collision of the float valve body 70ab with the discharge cover 51 is avoided. There is an effect that can be done. Further, when the thin oil return chamber equalizing hole 70d as shown in FIG. 10 is provided, a float valve capable of satisfactorily damping vibration can be realized by the damper effect. As a result, breakage of the float valve 70 can be avoided, so that the reliability of the oil return means can be improved.

  Also, consider a case where the oil in the oil return chamber 95 runs out for some reason. At this time, since the sealing performance of the seal gap of the float valve portion 70b also deteriorates, there is a risk that the separated oil flows out through the seal gap and the normal state where the oil stays in the oil return chamber cannot be transferred. In this case, the working fluid is blown out together with the oil, and the working fluid is short-circuited from the discharge side to the suction side, resulting in a significant performance degradation. In the present embodiment, the compression amount of the float spring 70e is set to a size that pushes down the float valve body 70ab even when there is no return oil chamber staying oil 95b. Thereby, since the sealing performance of the float valve part 70b can be improved, there is an effect that the risk of not being able to shift to a state where oil stays in the oil return chamber can be reduced, and performance deterioration due to blow-through of the working fluid can be avoided.

(Fifth embodiment)
Next, the scroll compressor of 5th Embodiment of this invention is demonstrated using FIG. FIG. 14 is an enlarged longitudinal sectional view of a float valve hole (V portion in FIGS. 9 to 12) of a scroll compressor according to the fifth embodiment of the present invention. The fifth embodiment is different from the first to fourth embodiments in the following points, and the other points are the same as those in the first to fourth embodiments. .

  In the fifth embodiment, a float oil return groove 80a1 is provided on the inner peripheral surface of the float valve hole 70c of the oil return path 80, and the float oil return path 80a is communicated with the float oil return groove 80a1. In other words, when the float oil return passage 80a is formed into a slanted hole as shown in FIG. 8 or the like, a communication port between the oil return chamber 95 and the oil storage portion 125 (formed on the side wall surface of the float valve hole) if the processing accuracy is as low as possible. Further, there is a risk that the position in the vertical direction of the downstream oil return passage opening 80y1) is greatly shifted.

  On the other hand, according to this embodiment, the float oil return groove 80a1 is formed first, and the float oil return path 80a is communicated with the float oil return groove 80a1. According to this, even if the accuracy of the oblique hole machining of the float oil return passage 80a is somewhat worse, it is only necessary to communicate with the float oil return groove 80a1, so that the float valve body 70ab floats when the float valve 70 opens. The height is clearly defined, and variation in the amount of oil staying in the oil return chamber 95 can be reduced. As a result, there is an effect that the amount of oil sealed in the compressor can be reduced.

(Sixth embodiment)
Next, the scroll compressor of 6th Embodiment of this invention is demonstrated using FIG. FIG. 15 is an enlarged vertical cross-sectional view of a float valve hole (portion V in FIGS. 7, 12, and 13) of a scroll compressor according to a sixth embodiment of the present invention. The sixth embodiment is different from the first to fourth embodiments in the following points, and the other points are the same as those in the first to fourth embodiments. .

  In the sixth embodiment, the float oil return path that opens to the inner peripheral surface of the float valve hole 70c is an orthogonal float oil return path 80d that is substantially orthogonal to the axis of the float valve hole 70c. As a result, the floating height of the float valve body 70ab when the float valve 70 is opened is clearly defined, the variation in the amount of oil staying in the oil return chamber 95 can be reduced, and the inner circumference as in the fifth embodiment can be reduced. Since the groove processing on the surface becomes unnecessary, the processing becomes easy.

  Further, in this case, the downstream oil return passage 80y that connects the float valve 70 and the space in the casing is provided with a horizontal float oil return passage (80a ′ in FIG. 6) provided in the discharge oil separation oil return cylinder 55 and a fixed oil return groove 80b ′. It becomes. As a result, the amount of oil sealed in the compressor can be reduced, and the processing cost can be reduced.

(Seventh embodiment)
Next, the scroll compressor of 7th Embodiment of this invention is demonstrated using FIG. FIG. 16 is an enlarged longitudinal sectional view of a float valve hole (V portion in FIGS. 7, 12, and 13) of a scroll compressor according to a seventh embodiment of the present invention. The seventh embodiment is different from the first to sixth embodiments in the following points, and the other points are the same as those in the first to sixth embodiments. .

  In the seventh embodiment, an oil return equalizing passage 750 is formed by extending the oil communication passage 75 and working with an oil return equalizing hole (see 70d in FIG. 8). As a result, the oil return equalizing passage 750 and the valve lower space 78 become the upstream oil return passage 80x. Since it is possible to perform two oblique hole processing which is difficult to process at a time, the processing becomes easy. As a result, there is an effect of reducing the processing cost. Further, as described in the first embodiment, by increasing the flow resistance of the oil return equalizing hole 70d, it becomes a damper of the float valve body. In the case of this embodiment, the oil return equalizing passage 750 and By adjusting the cross-sectional area of the oil orifice part 750a which is the opening part of the float valve hole 70c at the time of processing, the flow resistance can be adjusted and the damper effect can be realized.

(Eighth embodiment)
Next, the scroll compressor of 8th Embodiment of this invention is demonstrated using FIG. FIG. 17 is an enlarged vertical cross-sectional view of a float valve body and a float valve hole (portion V in FIGS. 7, 12, and 13) of a scroll compressor according to an eighth embodiment of the present invention. The eighth embodiment is different from the first to seventh embodiments in the following points, and the other points are the same as those in the first to sixth embodiments. .

  In the eighth embodiment, the oil return equalization hole (see 70d in FIG. 8) provided in the discharge oil separation oil return cylinder 55 is eliminated, and the valve portion vertical hole 70b2 of the valve oil return passage 70b1234 is removed from the lower surface of the float valve portion 70b. The valve body through-return oil equalizing hole 70b12 that connects the upper valve part horizontal hole 70b1 and the valve part vertical hole 70b2 is formed by opening the upper part. This valve body through oil return equalizing hole 70b12 can be realized by eliminating the vertical hole plug 70b5 in the float valve portion 70b in the first to sixth embodiments (see FIG. 8).

  As a result, there is an effect that the processing cost is reduced. Further, since the opening on the valve portion lower space 78 side of the valve body through oil return equalizing hole 70b12 is provided at the center of the lower surface of the float valve portion 70b, when the float valve body 70ab is displaced downward most, the oil return chamber 95 is provided. There is a danger of clogging at the bottom. For this reason, let the lower surface of the float valve part 70b be the concave lower surface 70b7. Thereby, the pressure of the valve portion lower space 78 can always be the same as that of the oil return chamber 95.

(Ninth embodiment)
Next, the scroll compressor of 9th Embodiment of this invention is demonstrated using FIG. FIG. 18 is an enlarged vertical cross-sectional view of a float valve body and a float valve hole (portion V in FIGS. 8, 12, and 13) of a scroll compressor according to a ninth embodiment of the present invention. The ninth embodiment is different from the eighth embodiment in the following points, and the other points are the same as those in the eighth embodiment, so that the duplicate description is omitted.

  In the ninth embodiment, a throttle plug 70b8 that opens a thin needle hole is packed at the lower end of the valve body penetration oil return equalizing hole 70b12. Thereby, since the flow path resistance of the oil return equalizing hole can be increased, it becomes a damper for the vertical movement of the float valve body 70ab. As a result, the damping action of the vertical movement of the float valve body 70ab works, and unexpected resonance can be suppressed. This has the effect of avoiding breakage of the float valve.

(10th Embodiment)
Next, a scroll compressor according to a tenth embodiment of the present invention will be described with reference to FIG. FIG. 19 is an enlarged vertical cross-sectional view of a float valve body and a float valve hole (portion V in FIGS. 8, 12, and 13) of a scroll compressor according to a tenth embodiment of the present invention. The tenth embodiment is different from the eighth embodiment in the points described below, and the other points are the same as those in the eighth embodiment, so that the duplicate description is omitted.

  In the tenth embodiment, the lower valve side lateral hole 70b3 is eliminated, and the opening in the float valve hole 70c of the downstream oil return passage 80y is lowered to the vicinity of the concave lower surface 70b7. Thus, the upstream oil return passage 80x is constituted by the upper valve portion lateral hole 70b1, the valve portion vertical hole 70b2, and the valve portion lower space 78. Further, the pressure equalizing path for keeping the valve lower space 78 at the same pressure as that of the oil return chamber 95 is constituted by the upper valve horizontal hole 70b1 and the valve vertical hole 70b2, as in the eighth embodiment.

  As described above, the passage connecting the upper valve portion horizontal hole 70b1 and the valve portion vertical hole 70b2 becomes the valve portion through passage 70b120 that plays the role of the oil pressure passage as well as the pressure equalizing passage. As a result, the oil passage and the pressure equalizing passage can be formed with a very simple flow passage configuration, which has the effect of reducing the processing cost.

(Eleventh embodiment)
Next, a scroll compressor according to an eleventh embodiment of the present invention will be described with reference to FIG. FIG. 20 is an enlarged vertical cross-sectional view of a float valve body and a float valve hole (portion V in FIGS. 7, 12, and 13) of a scroll compressor according to an eleventh embodiment of the present invention. The eleventh embodiment is different from the tenth embodiment in the following points, and the other points are the same as those in the tenth embodiment, so that duplicate explanations are omitted.

  In the eleventh embodiment, the cylinder through passage 7500 that connects the oil separation chamber 90, the oil return chamber 95, and the valve portion lower space 78 plays three roles: an oil communication passage, a pressure equalization passage, and an upstream oil return passage. Is. As a result, there is no need for drilling the float valve portion 70b, and the oil passage and the pressure equalization passage can be formed with a very simple flow path configuration, so that the processing cost can be greatly reduced.

  Further, since the shape can be processed from the bottom surface side of the discharge oil separation oil return cylinder 55, the burr and facet can be easily processed, and the processing cost can be further reduced. Further, as described above, since it is not necessary to form an oil flow path in the float valve portion 70b, the valve portion hollow portion 70b10 can be provided, and the weight can be reduced. Thereby, since the gravity of gravity acting on the float valve body 70ab is reduced, there is an effect that the float valve can be downsized by the downsizing of the float 70a.

(Twelfth embodiment)
Next, the scroll compressor of 12th Embodiment of this invention is demonstrated using FIG. FIG. 21 is an enlarged longitudinal sectional view of a float valve body and a float valve hole (V portion in FIGS. 8, 12, and 13) of a scroll compressor according to a twelfth embodiment of the present invention. The twelfth embodiment is different from the eleventh embodiment in the following points, and the other points are the same as those in the eleventh embodiment, so that the duplicate description is omitted.

  In the twelfth embodiment, the oil return chamber 95 and the valve lower space 78 are connected, the valve lower space 78 is taken together with the pressure equalizing passage, and the upstream side oil return passage serves as the upstream oil return passage. A cylinder side hole 70b9 that connects the cylinder through passage 7500 and the inner peripheral surface of the float valve hole 70c, and a valve portion peripheral groove 70b4 are provided so that the side oil return passage does not use the valve lower space 78. . Here, the cylinder side hole 70b9 and the float oil return path 80a are orthogonal to the axis of the float valve hole 70c.

  The float valve body 70ab moves up, and the valve portion peripheral groove 70b4 moves to the height of the cylinder side hole 70b9 and the float oil return path 80a, whereby the float valve 70 opens. That is, the upper part of the cylinder through passage 7500, the cylinder side hole 70b9 and the valve portion peripheral groove 70b4 constitute the upstream oil return path 80x, and the float oil return path 80a constitutes the downstream oil return path 80y.

  Similarly to the seventh embodiment, the flow resistance of the oil flow path between the valve portion lower space 78 and the oil return chamber 95 is set large by adjusting the amount of penetration of the cylinder through passage 7500 and the float valve hole 78. Therefore, the damper effect of the vertical movement of the float valve body 70ab can be realized. Further, since the cylinder horizontal hole 70b9 and the axis of the float oil return path 80a coincide with each other, simultaneous machining becomes possible and machining becomes easy. As a result, since the oil passage and the pressure equalizing passage can be formed with a very simple flow passage configuration while realizing the damper effect of the vertical movement of the float valve body 70ab, there is an effect that the processing cost can be greatly reduced.

(13th Embodiment)
Next, the scroll compressor of 13th Embodiment of this invention is demonstrated using FIG. FIG. 22 is a side view of the float valve of the scroll compressor according to the thirteenth embodiment of the present invention. The thirteenth embodiment is different from the first to twelfth embodiments in the following points, and the other points are the same as those in the first to twelfth embodiments. .

  In the thirteenth embodiment, the float outermost peripheral surface 70ab2 which is the outermost periphery of the side surface of the float valve body 70ab is limited to the float uppermost outermost peripheral portion 70a11 at the upper side surface, and the other side surface portions are formed by the oil condensing force. The clearance is set so as not to be in close contact with the oil return inner peripheral surface 95c. The width of the float uppermost outer peripheral portion 70a11 is set as small as possible (about 1 to 5 mm), and the frictional force generated there is suppressed to smooth the vertical movement of the float valve body 70ab.

  In FIG. 22, in order to clearly indicate the float uppermost outer peripheral portion 70 a 11, the amount of protrusion is emphasized more than the actual amount, and is actually about 0.1 mm to 5 mm. As a result, there is an effect that the float 70a and the oil return inner peripheral surface 95c are not attracted and the float valve 70 is reliably opened and closed. Further, since the float uppermost outer peripheral portion 70a11 is located between the oil surface of the return chamber retaining oil 95b and the float outer opening 70a6, oil mist generated by the undulation of the oil surface of the return chamber retaining oil 95b is generated in the float 70a. Suppresses intrusion. As a result, there is an effect that the certainty of the opening / closing operation of the float valve 70 is improved.

  Further, the float uppermost outer peripheral portion 70a11 may be separated from the main body of the float 70a, and the float upper outermost peripheral portion 70a11 may be sandwiched between the float lower body 70a1 and the float upper body 70a2. Thereby, the side surface of the float lower body 70a1 becomes a simple circumference, and extrusion molding becomes easy. As a result, the manufacturing cost is reduced.

  Further, a plurality of vertical grooves 70a13 may be provided at equal intervals in the float uppermost outer peripheral portion 70a11. Thereby, the oil discharged | emitted from the float outer side opening part 70a6 can be easily returned to the lower part of the oil return chamber 95 with the oil return chamber retention oil 95b. As a result, the oil discharged from the float outer opening 70a6 quickly returns to the oil return chamber staying oil 95b, so that the risk of entering the float 70a again is low and the opening operation of the float valve 70 is ensured. is there.

  Of course, even if the vertical groove 70a13 is not provided, the oil discharged from the float outer opening 70a6 is returned to the lower part of the return oil chamber 95 where the return oil staying oil 95b is located by setting an appropriate gap in the outermost peripheral part 70a11 of the float upper part. be able to. Further, the outermost peripheral surface 70ab2 of the float may be provided not only at the upper part of the float but also at the lower part of the float. Thereby, the one-sided contact of the float valve part 70b is eased, and there is an effect that damage can be avoided.

(14th Embodiment)
Next, a scroll compressor according to a fourteenth embodiment of the present invention is described with reference to FIG. FIG. 23 is a float side view of the scroll compressor according to the fourteenth embodiment of the present invention. The fourteenth embodiment is different from the thirteenth embodiment in the following points, and the other points are the same as those in the thirteenth embodiment.

  In the fourteenth embodiment, a float outer peripheral contact body 70a12 is provided which reaches the oil return chamber staying oil 95b from the float uppermost outer peripheral portion 70a11 of the float valve body 70ab and comes into contact with the outer periphery of the float 70a. And the outer diameter of this float outer periphery contact body 70a12 shall be below float uppermost outer peripheral part 70a11. Although the present embodiment has a spiral shape, the present invention is not limited to this, and may be a mesh shape or a hook shape. Due to the capillary phenomenon, a small amount of the oil return chamber staying oil 95b rises to the float uppermost outermost peripheral portion 70a11 through the gap between the outer periphery of the float 70a and the float outer peripheral contact body 70a12. For this reason, since an appropriate amount of oil can be supplied to the float uppermost outer peripheral portion 70a11 that slides with the oil return inner peripheral surface 95c in an environment where there is almost no oil in the surrounding working fluid, the float valve body 70ab The vertical movement is smooth, and the reliability of the operation of the float valve 70 is improved.

  The positive displacement compressor of the present invention has been described above using each embodiment. According to the positive displacement compressor of the present invention, the float valve that is the oil return means can minimize the buoyancy required to open the float valve, so that the float can be made compact. Furthermore, since the buoyancy increasing mechanism represented by the lever mechanism is not required, the parts other than the float in the oil return means are made compact and the operation is simplified, so that the reliability of the operation is improved.

  Further, unlike the conventional needle type, the valve portion can avoid strong contact with the valve portion, and can avoid deformation and breakage of the valve portion. Thus, there is an effect that a compact and highly reliable oil return means can be realized while the oil return operation is reliably executed. As a result, when this oil return means is connected to the discharge pipe of the positive displacement compressor as an auxiliary device, and accordingly, an oil return pipe that connects the oil return passage to the oil storage chamber of the positive displacement compressor is provided, the piping space is reduced. In addition, there is an effect that the entire apparatus composed of the positive displacement compressor and the auxiliary device can be made compact.

  In addition, when this oil return means is built in a positive displacement compressor, the positive displacement compressor can avoid an increase in size due to the compactness of the oil return mechanism, and there is no need to provide an external oil return pipe. There is an effect that manufacturing becomes easy. Further, the improvement in the reliability of the oil return means has an effect of improving the reliability of the compressor incorporating the oil return means. Moreover, since an auxiliary device for oil return is not required, there is an effect that usability is improved.

  In each of the above-described embodiments, a columnar float valve hole that forms part of the oil return chamber is formed at the bottom of the oil return chamber, and the communication port between the oil return chamber and the oil storage portion serves as a side wall surface of the float valve hole. The float valve portion has a side wall surface opposed to the side wall surface of the float valve hole through a seal gap, and is formed in a column shape that moves along the column axis direction as the float moves up and down. ing. However, the positive displacement compressor of the present invention is not limited to such a configuration. For example, if the bottom wall surface of the oil return chamber is formed flat in the horizontal direction, and the communication port is formed in this bottom wall surface, the float valve portion has a communication port when there is little or no oil. In addition to covering and closing, when the oil increases and the float rises, it can be configured to move horizontally along the bottom wall surface to open the communication port.

  In short, if the float valve part covers and closes the communication port and moves along the inner wall surface where the communication port of the oil return chamber is formed as the float moves up and down, it opens and closes the communication port Good. Then, the space facing the one end surface in the movement direction of the float valve portion and the space facing the other end surface are communicated with each other so that a differential pressure in the movement direction of the float valve portion does not occur.

It is a longitudinal cross-sectional view of the scroll compressor which concerns on 1st-13th embodiment of this invention. It is a detailed enlarged view of an oil supply pump (Drawing 1M section). It is a detailed enlarged view of the back pressure chamber vicinity (FIG. 1N part). It is a detailed enlarged view of an oil separation oil return chamber (FIG. 1P part). It is FF sectional drawing of FIG. It is an expanded sectional view of an oil return chamber (Q part of Drawing 1). It is an expanded vertical sectional view of a float valve body (S section of Drawing 6). It is a detailed enlarged view of a float valve part (Drawing 7V part). FIG. 7 is an enlarged longitudinal sectional view of an oil return chamber when there is little oil in the return chamber and the float valve body does not float and the float valve (S in FIG. 6) is closed. FIG. 7 is an enlarged vertical cross-sectional view of an oil return chamber when a float valve body floats and a float valve (S in FIG. 6) is opened. FIG. 7 is an enlarged longitudinal sectional view of an oil return chamber when a float valve (S in FIG. 6) is opened to the maximum. It is an expansion longitudinal cross-sectional view of the float valve body (FIG. 6S part) of the scroll compressor which concerns on 2nd Embodiment of this invention. It is an expansion longitudinal cross-sectional view of the float valve body (FIG. 6S part) of the scroll compressor which concerns on 3rd Embodiment of this invention. It is an expansion longitudinal cross-sectional view of the float valve body (FIG. 6S part) of the scroll compressor which concerns on 4th Embodiment of this invention. FIG. 14 is an enlarged vertical sectional view of a float valve hole (V portion in FIGS. 7, 12, and 13) of a scroll compressor according to a fifth embodiment of the present invention. FIG. 14 is an enlarged vertical sectional view of a float valve hole (V portion in FIGS. 7, 12, and 13) of a scroll compressor according to a sixth embodiment of the present invention. FIG. 14 is an enlarged longitudinal sectional view of a float valve hole (V portion in FIGS. 7, 12, and 13) of a scroll compressor according to a seventh embodiment of the present invention. FIG. 14 is an enlarged vertical sectional view of a float valve body and a float valve hole (V portion in FIGS. 7, 12, and 13) of a scroll compressor according to an eighth embodiment of the present invention. It is an enlarged longitudinal cross-sectional view of the float valve body and float valve hole (V part of FIG.7, FIG.12, FIG.13) of the scroll compressor which concerns on 9th Embodiment of this invention. It is an enlarged longitudinal cross-sectional view of the float valve body and float valve hole (V section of FIG.7, FIG.12, FIG.13) of the scroll compressor which concerns on 10th Embodiment of this invention. FIG. 14 is an enlarged longitudinal sectional view of a float valve body and a float valve hole (V portion in FIGS. 7, 12, and 13) of a scroll compressor according to an eleventh embodiment of the present invention. It is an enlarged longitudinal cross-sectional view of the float valve body and float valve hole (V part of FIG.7, FIG.12, FIG.13) of the scroll compressor which concerns on 12th Embodiment of this invention. It is a float valve side view of the scroll compressor which concerns on 13th Embodiment of this invention. It is a float valve side view of the scroll compressor which concerns on 14th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scroll compressor 7 Motor 8 Casing 10 Compression chamber structural part 30 Oil supply pump 55 Discharged oil separation oil return cylinder 70a Float 70a1 Float lower body 70a2 Float upper body 70a3 Float hollow part 70ab Float valve body 70ab1 Float lower integrated valve body 70ab2 Outermost peripheral surface 70b Float valve part 70b1 Upper valve part side hole 70b2 Valve part vertical hole 70b3 Lower valve part side hole 70b4 Valve part peripheral groove 70e Float spring 75 Oil communication path 80 Oil return path 80a Float oil return path 80a1 Float oil return groove 80b Fixed return Oil passage 80c Frame oil return passage 80x Upstream oil return passage 80y Downstream oil return passage 90 Oil separation chamber 95 Oil return chamber 100 Compression chamber 120 Discharge chamber 125 Oil reservoir

Claims (10)

A compression chamber constituting portion that constitutes a compression chamber that compresses the working fluid, an oil storage portion that stores oil to be supplied to the compression chamber, and an oil separation means that separates the oil from the working fluid compressed and discharged in the compression chamber And an oil return means for returning the separated oil separated by the oil separation means to the oil storage section, a compression chamber component, the oil storage section, the oil separation means, and a casing containing the oil return means. ,
The oil return means includes a return oil chamber that temporarily stores the separated oil guided from the oil separation means via an oil communication path, a float that floats on the separated oil stored in the oil return chamber, A float valve portion that opens and closes the communication port with the oil storage portion formed on the inner wall surface of the oil return chamber in conjunction with vertical movement, and the oil storage portion has a lower pressure than the oil return chamber. A positive displacement compressor held by
The float valve portion covers and closes the communication port, and moves along the inner wall surface where the communication port of the oil return chamber is formed to open and close the communication port as the float moves up and down. A space opposed to one end surface in the moving direction of the float valve portion and a space opposed to the other end surface,
It is float valve hole columnar form part of the oil return chamber to the bottom of the front Symbol oil return chamber forms, together with the communication port and said oil return chamber and the oil reservoir portion is formed on the side wall surface of the float valve hole The float valve portion has a side wall surface opposed to the side wall surface of the float valve hole via a seal gap, and is formed in a columnar shape that is movable along the column axis direction as the float moves up and down.
A return oil that communicates a float valve lower space formed by a side wall surface of the float valve hole, a bottom wall surface of the float valve hole, and a lower end surface of the float valve portion and a storage space for the separated oil in the oil return chamber. A positive displacement compressor in which a chamber pressure equalizing passage is formed, and an upstream oil return passage is formed by communicating the storage space for the separated oil in the oil return chamber and the communication port as the float rises. 2. The positive displacement compressor according to claim 1 , wherein the oil return chamber pressure equalizing path and the upstream oil return path are formed as separate flow paths. 2. The positive displacement compressor according to claim 1 , wherein the upstream oil return path is formed by a flow path that penetrates the inside of the float valve portion, and one end opening of the flow path stores the separated oil in the oil return chamber. A positive displacement compressor that communicates with a space and has an opening at the other end that communicates with a communication port between the oil return chamber and the oil storage portion by floating of the float. 2. The positive displacement compressor according to claim 1 , wherein the float and the float valve portion are integrally formed. 4. The positive displacement compressor according to claim 3 , wherein the center of the other end opening of the flow path passing through the inside of the float valve portion does not rise above the center of the communication port between the oil return chamber and the oil storage portion. A positive displacement compressor characterized in that a rising amount is defined. 2. The positive displacement compressor according to claim 1 , wherein the float and the top surface of the oil return chamber are connected by a spring member. 2. The positive displacement compressor according to claim 1 , wherein the oil return chamber pressure equalizing passage has at least a flow resistance of the oil return chamber equalizing passage communicating the upstream oil return passage and the communication port with the oil storage section. A positive displacement compressor formed to be larger than the flow path resistance of the downstream oil return path. The positive displacement compressor according to claim 1 , further comprising a guide rail mechanism that restricts horizontal movement of the float and allows vertical movement. 9. The positive displacement compressor according to claim 8 , wherein the guide rail mechanism is constituted by a side surface of the oil return chamber facing a side surface of the float. A compression chamber constituting portion that constitutes a compression chamber that reduces the volume and compresses the working fluid, a compression chamber driving portion that drives the reduction operation of the compression chamber, and a discharge fluid that is the working fluid compressed in the compression chamber is discharged. A discharge chamber, and a casing in which the compression chamber constituting portion, the compression chamber driving portion, and the discharge chamber are built, and an internal space is held at a pressure lower than the discharge pressure of the discharge chamber,
The internal space of the casing is provided with an oil storage part for storing oil, and a compression chamber oil supply means for guiding the oil in the oil storage part to the compression chamber,
The discharge chamber is separated by oil separation means for separating the oil supplied to the compression chamber by the compression chamber oil supply means and guided to the discharge chamber together with the working fluid from the working fluid. An oil return means for returning the separated oil to the oil storage part is provided,
The oil return means includes a return oil chamber that temporarily stores the separated oil guided from the oil separation means via an oil communication path, and a float that floats on the return oil chamber accumulated oil accumulated at the bottom of the oil return chamber. A positive displacement compressor configured to have a float valve portion that opens and closes a communication port with the oil storage portion formed on the inner wall surface of the oil return chamber in conjunction with the vertical movement of the float,
A columnar float valve hole forming a part of the oil return chamber is formed at the bottom of the oil return chamber, and a communication port between the oil return chamber and the oil storage portion is formed on a side wall surface of the float valve hole, The float valve portion has a side wall surface facing the side wall surface of the float valve hole via a seal gap, and is formed in a column shape movable along the column axis direction with the vertical movement of the float.
A return oil that communicates a float valve lower space formed by a side wall surface of the float valve hole, a bottom wall surface of the float valve hole, and a lower end surface of the float valve portion and a storage space for the separated oil in the oil return chamber. A positive displacement compressor in which a chamber pressure equalizing passage is formed, and an upstream oil return passage is formed by communicating the storage space for the separated oil in the oil return chamber and the communication port as the float rises.

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