CN113260791B

CN113260791B - Claw pump

Info

Publication number: CN113260791B
Application number: CN202080006096.6A
Authority: CN
Inventors: 小出智之; 丸山惠一; 小林和也
Original assignee: Orion Machinery Shanghai Co Ltd; Orion Machinery Co Ltd
Current assignee: Orion Machinery Shanghai Co Ltd; Orion Machinery Co Ltd
Priority date: 2019-10-28
Filing date: 2020-10-22
Publication date: 2022-03-29
Anticipated expiration: 2040-10-22
Also published as: KR20220081950A; JP6749714B1; CN113357146A; WO2021085282A1; CN113357146B; JP2021067245A; CN113260791A; DE112020000151T5

Abstract

Provided is a claw pump which can prevent a pump chamber from overheating and can further improve pump efficiency even when used in a range of high vacuum degree as a vacuum pump. The gas compressor is provided with a pump chamber (10) formed by a cylinder part (10A), one end wall part (10B) and the other end wall part (10c), two rotating shafts (20A, 20B), two rotors (30A, 30B) which are formed with hook-shaped claw parts in a manner of compressing sucked gas and discharging, an exhaust side opening part (50) which is arranged at least one part of the one end wall part (10B) and the other end wall part (10c) and is opened at a position facing to a part of the pump chamber (10) for compressing gas, wherein the exhaust side opening part (50) is arranged by a front stage vent hole (51) which is communicated with the outside of the pump chamber (10) at a front stage with the maximized compression ratio of the gas and a rear stage exhaust port (52) which is communicated with the outside of the pump chamber (10) in a manner of exhausting gas at a stage with the maximized compression ratio of the gas compared with the front stage.

Description

Claw pump

Technical Field

The present invention relates to a claw pump including a pump chamber having a cross-sectional shape in which a part of two circles are overlapped, and two rotors each having a hook-shaped claw portion formed so as to compress sucked gas and discharge the gas.

Background

As a conventional claw pump, the applicant proposed two rotors each including a cylinder forming a pump chamber, a side plate closing one end surface of the cylinder, and another side plate closing the other end surface of the cylinder, two rotary shafts arranged in parallel in the cylinder and rotating in opposite directions at the same speed, and a hook-shaped claw portion integrally fixed to the two rotary shafts and arranged in the cylinder and configured to mesh with each other in a non-contact state to compress sucked gas, a rotary drive device that rotationally drives the two rotors by the two rotary shafts, an intake port that communicates with a portion of the pump chamber that fails to compress the gas in the cylinder, and an exhaust port that opens in a portion of the pump chamber that compresses the gas in the cylinder in both directions of the one plate and the other plate so as to discharge the compressed gas from both sides through both end surfaces of the cylinder (see patent document 1).

According to this conventional claw pump, since the opening area of the intake port is increased to reduce the ventilation resistance of the exhaust gas, the exhaust efficiency can be improved. This can improve the pump performance and further improve the degree of freedom in design. This effect can be more effectively exhibited when used in a region where the degree of vacuum is low.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-38476 (first page, technical solution 1)

Disclosure of Invention

Problems to be solved by the invention

The claw pump has a problem that when the claw pump is used as a vacuum pump in a range where the vacuum degree is high, the vacuum degree is a value closer to the absolute vacuum, the pump chamber is overheated, and it is difficult to improve the pump efficiency. That is, in the case of the claw pump used in a range where the degree of vacuum is high, the pressure in the pump chamber is lower than the external pressure (for example, atmospheric pressure), and therefore the discharged exhaust gas may flow back through the exhaust port. Since the reverse flow of exhaust gas is gas discharged by being compressed and heated in the pump chamber, the gas is originally at a high temperature, and is compressed again and heated again in the pump chamber into which the gas flows in the reverse flow. As a result, the pump chamber is further overheated. When the pump chamber is overheated, the rotors that rotate due to thermal expansion interfere with each other, with the rotors interfering with components such as cylinders that form the pump chamber, and cause a failure. In order to prevent this, it is necessary to increase the distance between the components, and pump performance cannot be improved.

Accordingly, an object of the present invention is to provide a claw pump capable of preventing a pump chamber from being overheated and improving pump efficiency even when used as a vacuum pump in a range of high vacuum degree.

Means for solving the problems

The present invention has the following configuration to achieve the above object.

According to one aspect of the claw pump of the present invention, the claw pump includes a cylinder portion, one end wall portion provided on one end surface of the cylinder portion, and the other end wall portion provided on the other end surface of the cylinder portion so as to form a pump chamber having a cross-sectional shape in which two circles are partially overlapped, two rotary shafts arranged in parallel in the pump chamber and rotating in opposite directions at the same speed, two rotors provided on the two shafts and arranged in the pump chamber, respectively, and having hook-shaped claw portions that are capable of compressing sucked air and discharging the air by rotating in a mutually non-contact state, and an exhaust side opening portion provided in at least one of the one end wall portion and the other end wall portion and opening to a position facing a portion of the compressed gas in the pump chamber, the exhaust side opening portion being formed by a front stage vent hole communicating with an outside of the pump chamber at a front stage where a compression ratio of the gas is maximized by the claw portions of the two rotors, And a rear stage exhaust port which communicates with the outside of the pump chamber so as to exhaust gas including a stage where the compression ratio of the gas is maximized with respect to the front stage by the claw portions of the two rotors, wherein the front stage vent port is closed by the rotors at a stage where the rear stage exhaust port communicates with the outside of the pump chamber so as to maximize the compression ratio of the gas.

In addition, according to an aspect of the claw pump of the present invention, the front stage air vent is provided in the one end wall portion, and the rear stage exhaust port is provided in the other end wall portion.

In the claw pump according to the aspect of the invention, the two rotors are respectively disposed at one ends of the two rotary shafts and supported in a cantilever state, and the one end wall portion is located on one side of a bearing portion that supports the two rotary shafts.

In the claw pump according to the aspect of the invention, the front stage air vent and the rear stage exhaust port are provided so as to be divided so as not to overlap each other, as viewed in a state where they overlap each other in a direction in which the axis of the rotary shaft extends.

In the claw pump according to the aspect of the invention, the upstream vent port and the downstream exhaust port are formed by dividing a virtual single exhaust-side opening portion, in a manner that the upstream vent port and the downstream exhaust port are overlapped with each other in an extending direction of the axial center of the rotary shaft.

In the claw pump according to the aspect of the present invention, the front stage air port and the rear stage exhaust port are arranged so as to overlap each other at a portion of the rear stage exhaust port on the lower compression ratio side, as viewed in a direction in which the front stage air port and the rear stage exhaust port overlap each other in the direction in which the axial center of the rotary shaft extends.

In the claw pump according to the aspect of the present invention, the front stage air port and the rear stage exhaust port are arranged to overlap each other in a shape in which boundary lines of port edges forming a side where the compression ratio is low of the front stage air port and the rear stage exhaust port coincide with each other when viewed in a direction in which the axial center of the rotary shaft extends.

In the claw pump according to the aspect of the invention, the front stage air vent and the rear stage exhaust port are provided so as to be separated from each other so as not to overlap with each other, and the front stage air vent and the rear stage exhaust port are provided in one of the one end wall portion and the other end wall portion.

In the claw pump according to the aspect of the invention, the two rotors are disposed at one ends of the two rotary shafts and supported in a cantilever state, and the front stage air vent and the rear stage exhaust port are both provided in the other end wall portion located on the opposite side of the one end wall portion located on the side of the bearing portion supporting the two rotary shafts.

In addition, according to an aspect of the claw pump of the present invention, the pump body is divided so as to form a cooling gap between the pump chamber body provided by the cylinder portion and the end wall portions provided on both end surfaces of the cylinder portion so as to form the pump chamber and the bearing body provided with the bearing portions in which the two rotors are respectively arranged at one ends of the two rotary shafts and supported in a cantilever state so as to support the two rotary shafts.

Effects of the invention

According to the claw pump of the present invention, such a particularly advantageous effect that the pump chamber can be prevented from being overheated and the pump efficiency can be further improved even in the case of using as a vacuum pump in a range where the degree of vacuum is high can be achieved.

Drawings

Fig. 1 is a sectional view showing a main part of an embodiment of a claw pump relating to the present invention.

Fig. 2 is a perspective view showing an overall appearance of the embodiment of the claw pump according to the present invention.

Fig. 3 is an exploded view showing the main part of an embodiment of a claw pump relating to the present invention.

Fig. 4 is a perspective view showing an example of members (a cylinder housing and a side plate) forming a pump chamber.

Fig. 5 is a front view (a) of the side plate and a front view (b) of the cylinder housing, as viewed from the direction of the arrow a (see fig. 4).

Fig. 6 is a front view showing an embodiment in which an exhaust-side opening divided into a front stage air vent (solid line) and a rear stage exhaust port (broken line) is superimposed in the axial direction of the rotary shaft.

Fig. 7 is an operation diagram of an example showing a positional relationship between two rotors, a front stage air port and a rear stage air port during a rotation operation (states of three rotation positions of (a), (b), and (c)).

Fig. 8 is an explanatory diagram showing a divided embodiment of the exhaust side opening portion.

Fig. 9 is an explanatory diagram showing a divided embodiment of the exhaust side opening portion.

Fig. 10 is an explanatory diagram showing an overlapping type embodiment of the exhaust side opening portion.

Fig. 11 is an explanatory diagram showing an example of a boundary matching type of the exhaust side opening portion.

Fig. 12 is a perspective view showing an example in which divided exhaust side opening portions (a front stage vent port and a rear stage vent port) are provided on one surface of a side plate.

Fig. 13 is a side view including a cross section showing an example of the cooling air flow passage of the claw pump according to the present invention.

Fig. 14 is a perspective view including a section showing a main part of an embodiment of a claw pump relating to the present invention.

Detailed Description

Hereinafter, an embodiment of the claw pump according to the present invention will be described in detail with reference to the drawings (fig. 1 to 7).

As shown in fig. 1, 3, and the like, the claw pump according to the present invention includes a cylinder portion 10a, one end wall portion 10b provided on one end surface of the cylinder portion 10a, and the other end wall portion 10c provided on the other end surface of the cylinder portion 10a so as to form a pump chamber 10 (see fig. 13 and the like) having a cross-sectional shape in which portions of two circles are overlapped.

As shown in fig. 3 and the like, the two

rotary shafts

20A and 20B are disposed in parallel in the pump chamber 10 and rotate in opposite directions at the same speed. In the present embodiment, the two

rotary shafts

20A and 20B are provided with a gear 21A (driving side gear) and a gear 21B (driven side gear) integrally fixed to each other. The pair of

gears

21A, 21B are internally meshed with a gear case 45 provided in the bearing unit body 200.

As shown in fig. 3 and the like, the two

rotary shafts

20A and 20B are provided with a gear 21A (driving side gear) and a gear 21B (driven side gear) integrally fixed, respectively. The pair of

gears

21A and 21B mesh with the transmission case 45 provided in the bearing unit body 200.

As shown in fig. 3 and the like, the two

rotors

30A and 30B are provided on the two

rotary shafts

20A and 20B, respectively, are disposed in the pump chamber 10, and form hook-shaped claw portions so as to be capable of rotating in a non-contact state with each other to compress and discharge the sucked gas.

As shown in the figures, the exhaust-side opening 50 is provided so as to open at least one of the one end wall 10b and the other end wall 10c at a position facing the compressed gas in the pump chamber 10. Thus, a claw pump, which is one type of a two-shaft rotary pump, is configured. Further, reference numeral 15 denotes an intake port, which is provided at a position facing the uncompressed gas in the pump chamber 10 (a wall portion forming the cylinder portion 10a in the present embodiment) so as to be opened.

In the claw pump according to the present invention, the exhaust side opening portion 50 is provided by the pre-stage vent port 51 and the post-stage exhaust port 52, the pre-stage vent port 51 communicates with the outside of the pump chamber 10 in the pre-stage in which the gas compression ratio is maximized by the claw portions of the two

rotors

30A and 30B, and the post-stage exhaust port 52 communicates with the outside of the pump chamber 10 so as to include a stage in which the gas compression ratio is maximized with respect to the pre-stage by the claw portions of the two

rotors

30A and 30B. In the present embodiment, the state of communication with the outside of the pump chamber 10 is a state of communication with the atmosphere as the outside air and open.

According to the claw pump according to the present invention, even when the claw pump is used as a vacuum pump in a range where the vacuum degree is high, which is a value closer to the absolute vacuum, the pump chamber can be prevented from overheating, and the pump efficiency can be remarkably improved. That is, the exhaust side opening 50 is constituted by a front stage vent port 51 and a rear stage exhaust port 52 which are provided so as to be opened, respectively. Therefore, when used in a high vacuum, the non-overheated outside air is sucked into the front stage vent 51, and the reverse flow of the exhaust gas as in the conventional art can be reduced in the rear stage exhaust port 52, so that the pump chamber can be prevented from overheating.

That is, when the claw pump according to the present invention is used in a high range in which the degree of vacuum is constant or higher, a negative pressure may be generated even in a portion where the interior of the pump chamber is compressed, and the front vent 51 is opened to introduce non-overheated external gas (for example, cooling air at normal temperature and atmospheric pressure). Therefore, backflow of overheated gas (for example, air) in the later stage exhaust port 52 that is opened later can be prevented or suppressed, and an increase in the internal temperature of the pump chamber can be suppressed. That is, the structure including the front stage air vent 51 is a secondary cooling intake structure. By performing the secondary cooling intake and sucking the outside air (cooling air) into the pump chamber 10 in this manner, the air volume (volume) of the outside appearance is the same as the air flow rate of the counter flow, and therefore the internal temperature of the pump chamber 10 can be reduced without changing the power. Therefore, overheating of the pump chamber 10 can be suppressed without reducing energy saving performance on the high vacuum side, which is an advantage of the claw pump, and pump performance can be significantly improved.

Further, as the vent opening that opens at a portion where the interior of the pump chamber 10 is compressed, it is also conceivable to provide the vent opening in the peripheral wall portion of the cylinder portion 10a so as to communicate with the outside in a situation where the compression ratio at the initial stage of compression at which the pump cycle is started is low. However, in such a case where air is introduced through the open vent at the initial stage of starting compression, the amount of air to be treated may increase excessively, and power consumption may increase.

In the embodiment shown in fig. 1 to 7, as shown in fig. 3 to 5, the pump chamber 10 is formed by a cylinder structural wall including a cylinder housing 11 having a cylinder portion 10a and one end wall portion 10b integrally formed therewith and a side plate 12 provided as the other end wall portion 10 c. In the present embodiment, the pump chamber 10 is mainly configured by a member divided into two parts, but the present invention is not limited to this, and may be configured by a member divided mainly into three parts, for example, the cylinder portion 10a, the one end wall portion 10b, and the other end wall portion 10 c.

The present invention is not limited to the embodiment in which the two

rotors

30A and 30B are supported by bearings in a cantilever state, and can also be applied to a configuration of a claw pump in which the

rotary shafts

20A and 20B are supported by bearings so as to be rotatable at both ends.

In the present embodiment, as shown in fig. 1 to 7, the front stage vent 51 is provided in one end wall portion 10b, and the rear stage vent 52 is provided in the other end wall portion 10 c. That is, openings communicating with the outside air (in the present embodiment, the atmosphere) outside the pump chamber are provided in both of the pair of

end wall portions

10b and 10 c. This makes it possible to appropriately and easily provide the front stage vent port 51 and the rear stage exhaust port 52 in appropriate positions with an accurate shape. Therefore, the degree of freedom in designing the claw pump according to the required performance can be increased reasonably.

Next, the structure capable of preventing the pump chamber 10 from overheating by the claw pump of the present embodiment will be described in detail below.

In the conventional claw pump, when the exhaust port is opened at a certain degree of vacuum or more, the inside of the pump chamber becomes negative pressure, and a reverse flow of exhaust gas (for example, air at atmospheric pressure) is generated from the exhaust port. That is, in the conventional claw pump, high-temperature air (exhaust gas) inside the silencing muffler connected to the exhaust port (a space including the exhaust pipe 55 (see fig. 13)) may flow backward from the exhaust port, and this may cause an increase in the internal temperature of the pump chamber. Therefore, as a method of reducing the amount of reverse flow air, a method of increasing the compression ratio of exhaust gas by utilizing the shape of the exhaust port has been used. That is, if the area of the exhaust port is made small and the compression ratio of the exhaust gas is not higher than a predetermined value, the exhaust port is designed not to be opened. As described above, the higher the compression ratio is set, the more effective the backflow prevention is, and the power rise becomes larger in the operation on the low vacuum side, thereby limiting the usable vacuum range. That is, when the area of the exhaust port is reduced, the ventilation resistance of the exhaust gas becomes large in the use in the range of low vacuum degree, and therefore, a large power is required, and the energy consumption amount increases.

In contrast, in the claw pump of the present embodiment, when the claw pump is used in a range (for example, 60 to 95kPa) in which a predetermined high vacuum degree, such as a negative pressure, is generated even in a portion where the pump chamber 10 is compressed, the claw pump is configured to suck secondary cooling air through the secondary cooling air intake port (front stage air vent 51) on the side of the cylinder housing 11 (one end wall portion 10b) and pump exhaust air from the exhaust port (rear stage exhaust port 52) on the side of the side plate 12 (the other end wall portion 10 c). That is, the pre-stage vent 51, which is the opening on the one end wall portion 10b side, is provided in a shape that communicates with the outside when the compression ratio of the post-stage exhaust port 52, which is the opening on the other end wall portion 10c, is equal to or lower than the compression ratio.

According to the claw pump of this embodiment, when a predetermined high vacuum degree (for example, 80kPa or more) is generated, the negative pressure is maintained also at the portion where the compression in the pump chamber 10 is performed at the timing of a predetermined range which is a compression ratio lower than the final compression ratio. At this stage, the pre-stage air vent 51 is opened to communicate with the outside air (for example, air at atmospheric pressure), and the secondary cooling intake is performed. Then, the cooling air taken in is compressed to a final compression ratio in addition to the cooling air, and is discharged from the rear stage exhaust port 52. That is, in the stage where the subsequent stage discharge port 52 is opened to finally discharge the gas, the negative pressure in the portion where the interior of the pump chamber 10 is compressed can be released by sucking the cooling air, and the reverse flow at the subsequent stage discharge port 52 can be prevented or suppressed in the subsequent discharge step. Therefore, overheating of the pump chamber 10 can be suppressed, and the temperature rise of about 100 ℃ can be suppressed in the embodiment, and the pump efficiency can be improved.

Hereinafter, the embodiments shown in fig. 1 to 6 will be described in detail in stages with respect to the exhaust step capable of preventing the pump chamber 10 from overheating, based on fig. 7.

In the stage of fig. 7(a), both the pre-stage air vent 51 and the post-stage exhaust port 52 are closed by one rotor 30A. That is, the main body large diameter region of the one rotor 30A is overlapped, and both the front stage air vent 51 and the rear stage exhaust port 52 are blocked. Therefore, in this stage (section), neither the air discharge nor the air suction is performed with respect to the portion where the compression in the pump chamber 10 is performed.

In the stage of fig. 7(b), the pre-stage air vent 51 is opened, and the post-stage exhaust port 52 is closed by one rotor 30A. That is, only the rear stage exhaust port 52 is blocked by the main body large diameter region portion of the one rotor 30A.

The pre-stage vent 51 of the present embodiment is a portion that compresses the interior of the pump chamber 10, and communicates with a portion having a compression ratio of, for example, 2.0 to 2.4. As described above, when the portion in which the interior of the pump chamber 10 is compressed is at negative pressure, the front stage air vent 51 functions as a secondary cooling intake port that takes in outside air.

The front stage vent 51 of the present embodiment is formed by a groove 51a (see fig. 3 and the like) and a through hole 51b connected to the groove 51a, and is configured so that a part of the groove 51a is opened and can communicate with the outside through the through hole 51 b. That is, the groove portion 51a designed in the range of the thickness of the member and the through hole portion 51b formed to penetrate so as to communicate with a portion continuous with the groove portion 51a and communicate with the outside are included. The through hole 51b of the present embodiment is formed in an L-shaped curved shape so as to be opened downward and outward (see fig. 1 and the like). The opening of the through hole 51b facing the outside is formed in a circular shape, and for example, a connection pipe or the like may be connected as a connection portion. Further, if a pipe as a communication passage can be connected to the circular opening, the forward vent 51 can be selectively moved to a position where it is opened to the outside at a position away from the rear exhaust port 52, and a gas such as air at a lower temperature can be sucked.

The pre-stage vent 51 functions as an exhaust port by opening as shown in fig. 7(b) during operation under low vacuum. That is, the portion in the pump chamber 10 where the compression is performed does not become negative pressure until the inside of the pump chamber 10 reaches a predetermined high vacuum degree, and in this state, the compressed gas (for example, air) can be exhausted from the front stage vent hole 51. Therefore, the backing vent 51 is a backing vent at this time. This can reduce the ventilation resistance of the exhaust gas, and thus can suppress the power consumption.

In the stage of fig. 7(c), the rear stage exhaust port 52 is opened, and the front stage vent port 51 is closed by a rotor 30A. That is, only the pre-stage air port 51 side is closed by the main body portion including the claw portion of the rotor 30A. Further, the rear stage exhaust port 52 is opened by positioning a small diameter region of the main body of the rotor 30A so that the rotor 30A does not overlap the rear stage exhaust port 52. The portion of the pump chamber 10 that is in communication with the opened rear-stage exhaust port 52 and is compressed is cooled by the intake of outside air into the front-stage air vent 51, and the compression ratio is increased, and is increased in pressure compared to the outside air, and the exhaust is appropriately performed without causing a reverse flow in the rear-stage exhaust port 52. The rear-stage discharge port 52 of the present embodiment communicates with a portion where the interior of the pump chamber 10 is compressed, for example, 2.4 or more or 3.0 or more.

This can further improve the pump performance as described above.

In the present embodiment, as shown in fig. 3 and the like, the two

rotors

30A and 30B are disposed at one ends of the two corresponding

rotary shafts

20A and 20B and supported in a cantilever manner, and the one end wall portion 10B is located on the bearing portion 40 side supporting the two

rotary shafts

20A and 20B. With this configuration, the cantilever-supported claw pump having a small number of parts and a simple structure can be suitably configured.

Fig. 8 shows a first example of the exhaust side opening 50, which is adopted for the above-described embodiment (see fig. 1 to 7), and in order to show the manner thereof more easily, the opened space is marked with hatching while being enlarged as compared with fig. 1 to 7. That is, in the first example, the front vent 51 and the rear exhaust port 52 are divided so that they do not overlap each other, as viewed in a state where they overlap each other in the direction in which the axial centers of the

rotary shafts

20A and 20B extend. That is, the front stage air vent 51 and the rear stage exhaust port 52 are arranged so as to be spaced apart by a predetermined distance so as not to overlap each other, and are divided. Therefore, in this case, as shown in fig. 7(b), the continuity of the exhaust side opening 50 formed by the front stage vent port 51 and the rear stage exhaust port 52 is instantaneously cut off.

Fig. 9 shows a second example of the exhaust side opening 50, in which a virtual single exhaust side opening 50 is divided into two in a manner such that the front stage vent 51 and the rear stage exhaust port 52 are overlapped with each other in the extending direction of the axial center of the

rotary shafts

20A and 20B. That is, the front stage air vent 51 and the rear stage exhaust port 52 are formed so as to be divided so as to cut off the virtual one exhaust side opening 50.

Fig. 10 shows a third example of the exhaust side opening 50, and the front stage air vent 51 and the rear stage exhaust port 52 are arranged so as to overlap each other in a portion of the rear stage exhaust port 52 at a low compression ratio, in a state where they overlap each other in the direction of extension of the axial center of the

rotary shafts

20A and 20B.

Fig. 11 shows a fourth example of the exhaust side opening portion 50, in which the front stage vent port 51 and the rear stage exhaust port 52 are overlapped with each other in the extending direction of the axial center of the

rotary shafts

20A and 20B, and are arranged so as to overlap each other in a shape in which the boundary line 50A of the edges forming the lower compression ratio sides of the two ports coincides with each other.

In the above embodiment of the exhaust-side opening 50, the performance of the claw pump generating a high vacuum degree can be further improved as the opening area of the subsequent-stage exhaust port 52 is formed smaller. Further, the larger the opening area of the front stage vent 51 and the rear stage exhaust port 52 overlapping each other is formed, the more the performance of the claw pump for handling a larger air volume can be improved.

In the present invention, as shown in fig. 12, the pre-stage air vent 51 and the post-stage exhaust port 52 are divided so as not to overlap each other when viewed in a state where they overlap each other in the direction of extension of the axial center of the

rotary shafts

20A and 20B, the two

rotors

30A and 30B are disposed at one ends of the two

rotary shafts

20A and 20B and supported in a cantilever manner, and both the pre-stage air vent 51 and the post-stage exhaust port 52 may be configured to be provided on the other end wall portion 10c located on the opposite side of the one end wall portion 10B located on the side of the bearing portion 40 supporting the two

rotary shafts

20A and 20B.

This makes it possible to appropriately arrange the pre-stage air vent 51 and the post-stage exhaust port 52 only on one surface of the end wall portion, appropriately arrange the pre-stage air vent 51 and the post-stage exhaust port 52, appropriately set the use conditions, and the like, and improve the degree of freedom in design including the relationship with other devices. That is, since there is a predetermined space between the front stage air vent 51 and the rear stage exhaust port 52, both can be cut off, and as shown in fig. 12, the opening of the front stage air vent 51 to the outside and the opening of the rear stage exhaust port 52 to the outside (the opening provided through the exhaust pipe 55) can be separated. Therefore, the non-overheated gas can be sucked into the front stage air port 51, and the performance of the claw pump can be improved as described above.

In the claw pump of the present invention, the configuration is not limited to the above configuration, and any one of a configuration in which both the front stage air port 51 and the rear stage air port 52 are disposed only in the one end wall portion 10b, a configuration in which both the front stage air port 51 and the rear stage exhaust port 52 are disposed in both the one end wall portion 10b and the other end wall portion 10c, a configuration in which the front stage air port 51 is disposed in the end wall portion of both and the rear stage exhaust port 52 is disposed in the end wall portion of one side, and a configuration in which the front stage air port 51 is disposed in the end wall portion of one side and the rear stage exhaust port 52 is disposed in the end wall portion of both may be employed. These methods may be selectively employed as appropriate depending on various use conditions. When the front stage air vent 51 and the rear stage exhaust port 52 are disposed on the end wall portions on both sides, the size, shape, or combination thereof may be selectively designed as appropriate depending on the use conditions, and it is needless to say that the same form is not necessary.

Next, a cooling method of the exterior of the claw pump according to the present embodiment will be described with reference to fig. 13 and 14.

Reference numeral 100 denotes a pump chamber body portion, and the pump chamber body portion 100 is provided so as to form the pump chamber 10 by a cylinder portion 10a and end

wall portions

10b and 10c provided on both end surfaces of the cylinder portion 10a, respectively.

Reference numeral 200 denotes a bearing portion main body portion, and the bearing portion 40 that supports the

rotary shafts

20A and 20B is provided in the bearing portion main body portion 200 so that the two rotors 30A (driving side rotors) and 30B (driven side rotors) are respectively disposed at one ends of the two rotary shafts 20A (driving side rotary shaft) and 20B (driven side rotary shaft) and supported in a cantilever state. The bearing body 200 and the pump chamber body 100 constitute a pump body.

The claw pump according to the present invention is configured such that the pump body is divided between the pump chamber body 100 and the bearing body 200 so that the cooling gap 60 is formed between the pump chamber body 100 and the bearing body 200.

According to the claw pump of the present invention, heat generated by driving is reduced from being transmitted to the bearing main body portion 200, and a particularly advantageous effect is obtained in that the service life of the functional components constituting the bearing 40 and the like can be prolonged. That is, according to the present invention, heat conduction can be minimized by dividing the pump chamber body 100 and the bearing body 200. Further, by flowing cooling air between the pump chamber main body 100 and the bearing portion main body 200, heat conduction can be suppressed, and cooling by heat dissipation can be promoted. This can suppress a temperature rise in the bearing main body 200, and can prolong the life of the functional components.

The functional component is a component including the bearing 41 and the oil seal 42, and is used as a consumable component. By extending the life of these functional components, the running cost can be reduced.

In the present embodiment, as shown in fig. 1, 2, and the like, columnar coupling portions 101 and 201 (see fig. 1 to 3) for coupling are provided so that both of a portion of the pump chamber body 100 and a portion of the bearing body 200 form a pair. In the present embodiment, as is clear from fig. 3 and the like, the

columnar coupling portions

101 and 201 paired for this coupling are arranged in 4 pairs at positions corresponding to four corners of the main body. This allows the pump chamber body 100 and the bearing body 200 to be stably coupled. The fastening method used for the fastening of the present embodiment is a screw fastening using a bolt. However, the present invention is not limited to this embodiment, and the portion forming the cooling gap 60 may be formed in an integral structure. For example, in the case of manufacturing by cast molding, the gap 60 for cooling may be formed by a core.

In the present embodiment, the air blowing blade 75 that generates cooling air (see the arrow in fig. 13) is integrally fixed to a coupling portion 73 (see fig. 2) that couples the other end of the rotary shaft 20A and the drive shaft 71 of the drive motor 70, and as shown in fig. 13, an air blowing guide 80 that guides the flow of the cooling air is provided so that the cooling air generated by the rotation of the air blowing blade 75 flows over the surface of the pump chamber main body 100 to cool the pump chamber 10. This enables the cooling air to efficiently collide with the surface of the pump chamber body 100, thereby improving the cooling performance.

In the present embodiment, the air blow guide 80 is provided with a bottom air blow passage 81, and the bottom air blow passage 81 is formed as a passage below the bearing portion body 200 and the pump chamber body 100 so that the cooling air is blown upward from below the pump chamber body 100 and flows on the surfaces of the

end wall portions

10b and 10c of both sides of the pump chamber body 100, and guides the flow of the cooling air.

This enables both

end wall portions

10b and 10c of the pump chamber body 100 to be cooled simultaneously, and also enables the exhaust pipe 55 to be cooled, thereby enabling efficient cooling. In addition, a reasonable flow path in which the cooling air does not fly dust on the floor can be appropriately configured.

As shown in fig. 13, air blow guide 80 of the present embodiment is configured by a box-shaped cover 90 formed by a plate-shaped member so as to cover pump chamber body 100, bearing body 200, and coupling 73 (see fig. 2) disposed to integrally fix air blow blade 75. That is, an intake port 91 for introducing cooling air is provided in the vicinity of the blower blade 75 of the box-shaped cover 90, and the bottom blower passage 81 for guiding the flow of the cooling air is provided in a form (a form having a wide cross section of the passage) such that the cooling air discharged from the blower blade 75 can smoothly be directed toward the bearing main body 200 and the pump chamber main body 100. In order to increase the cooling performance by increasing the flow velocity of the cooling air flowing through the surfaces of the both

end wall portions

10b and 10c of the pump chamber main body portion 100, the flow path of the bottom blowing passage 81 is narrowed as it approaches the pump chamber main body portion 100 (the flow path has a narrow cross section). Then, the upper portion of the box-shaped cover 90 is provided with the discharge port 92 and the discharge port 93 so that the cooling air passing through the surfaces of the both

end wall portions

10b and 10c of the pump chamber body portion 100 smoothly flows from the lower side to the upper side. The suction port 91, the discharge port 92, and the discharge port 93 of the present embodiment are formed in a louver shape.

According to the cooling structure described above, the claw pump can be appropriately configured to appropriately correspond to the claw pump, and the cooling performance can be improved. In the claw pump according to the present invention, the lower side of the pump chamber 10 is easily overheated, and the structure can be appropriately formed to allow the cooling air to collide with the lower side as described above. Therefore, the pump chamber 10 can be efficiently cooled, and the pump performance can be improved and the life of the functional components can be prolonged.

Further, since the pre-stage air vent 51 is provided below the

rotary shafts

20A and 20B, the cooling air that has not been heated can be easily taken in, and the inside of the pump chamber 10 can be efficiently cooled. Therefore, the pump performance can be improved.

In the present embodiment, as shown in fig. 3 and 4, cooling

ribs

17 and 47 are provided on the surfaces of one end wall portion 10b forming the cooling gap 60 and the wall portion constituting the bearing portion 40 opposed thereto. These cooling

ribs

17, 47 are provided in a form extending in the vertical direction, and can guide the cooling air without obstructing the flow of the cooling air flowing from the bottom to the top, thereby improving the cooling efficiency.

The present invention will be described below by way of examples, but the present invention is not limited to these examples, and it is needless to say that various changes can be made without departing from the scope of the present invention.

Description of the symbols

10-a pump chamber, 10A-a cylinder portion, 10B-one end wall portion, 10 c-the other end wall portion, 11-a cylinder housing, 12-a side plate, 15-an intake port, 17-a cooling rib, 20A-a rotary shaft (drive-side rotary shaft), 20B-a rotary shaft (driven-side rotary shaft), 21A-a gear (drive-side gear), 21B-a gear (driven-side gear), 30A-a rotor (drive-side rotor), 30B-a rotor (driven-side rotor), 40-a bearing portion, 41-a bearing, 42-an oil seal, 45-a gear case, 47-a cooling rib, 50-an exhaust-side opening portion, 50A-a boundary line of an edge forming a compression ratio low side, 51-a preceding stage vent, 51A groove portion, 51B-a through hole portion, 52-a succeeding stage exhaust port, 55-an exhaust pipe, 60-a clearance for cooling, 70-a drive motor, 73-a coupling portion, 75-a blower blade, 80-blowing guide, 81-bottom blowing passage, 90-box-shaped cover, 91-suction inlet, 92-discharge outlet, 93-discharge outlet, 100-pump chamber body, 101-columnar connecting part, 200-bearing part body, 201-columnar connecting part.

Claims

1. A claw pump includes a cylinder portion, one end wall portion provided on one end surface of the cylinder portion, and the other end wall portion provided on the other end surface of the cylinder portion so as to form a pump chamber having a cross-sectional shape in which a part of two circles are overlapped,

the claw pump is provided with:

two rotating shafts disposed in parallel in the pump chamber and rotating in opposite directions at the same speed;

two rotors which are respectively arranged on the two rotating shafts and are configured in the pump chamber, and hook-shaped claw parts are formed in a manner that the rotors rotate in a mutually non-contact state and compress sucked air and can exhaust the air; and

an exhaust side opening provided at least one of the one end wall portion and the other end wall portion and opened at a position facing a portion in the pump chamber where gas is compressed by the claw portions of the two rotors,

the claw pump is characterized in that,

the exhaust side opening portion is provided by a backing vent port communicating with the outside of the pump chamber at a backing stage at which a compression ratio of gas is maximized by the claw portions of the two rotors, and a backing exhaust port communicating with the outside of the pump chamber so as to exhaust gas at a stage including a compression ratio of gas maximized as compared with the backing stage by the claw portions of the two rotors,

the pre-stage vent port is closed by the rotor at a stage when the post-stage vent port communicates with the outside of the pump chamber and the compression ratio of the gas is maximized,

the pump body is divided so that a cooling gap is formed between the pump chamber body and the bearing portion body, the pump chamber body is provided so as to form the pump chamber by the cylinder portion and the end wall portions provided on both end surfaces of the cylinder portion, and the bearing portion body is provided with a bearing portion that supports the two rotary shafts so that the two rotors are disposed at one end of the two rotary shafts, respectively, and are supported in a cantilever state.

2. The claw pump according to claim 1,

the front stage air vent is provided in the one end wall portion, and the rear stage exhaust port is provided in the other end wall portion.

3. A claw pump according to claim 1 or 2,

the two rotors are respectively disposed at one ends of the two rotating shafts and supported in a cantilever state, and the one end wall portion is located on a bearing portion side supporting the two rotating shafts.

4. A claw pump according to claim 1 or 2,

the front stage air vent and the rear stage exhaust port are arranged so as to be divided so as not to overlap each other, in a state where they are observed to overlap each other in a direction in which the axis of the rotary shaft extends.

5. The claw pump according to claim 1,

the front stage air vent and the rear stage exhaust port are divided so as not to overlap each other, and both the front stage air vent and the rear stage exhaust port are provided in one of the one end wall portion and the other end wall portion.

6. The claw pump according to claim 5,

the two rotors are disposed at one ends of the two rotating shafts and supported in a cantilever state, and both the front stage air vent and the rear stage exhaust port are provided in the other end wall portion located on the opposite side to the one end wall portion located on the bearing portion side supporting the two rotating shafts.