claw pump

Abstract

Claw pump comprising a pump chamber (10) with a cross-sectional shape in which parts of two circles overlap, and comprising a cylindrical section (10a), wherein an end wall section (10b) is arranged on one end face of the cylindrical section (10a) and the other end wall section (10c) is arranged on another end face of the cylindrical section (10a), in the pump chamber (10) two axes of rotation (20A, 20B) rotating parallel and at the same speed in opposite directions, two claw-shaped rotors (30a, 30B) arranged on each of the two axes of rotation (20A, 20B) in the pump chamber (10), which rotate relative to each other in a non-contact state and can compress and discharge the aspirated gas, and an exhaust-side opening (51) on at least one of the end wall section (10b) and the other end wall section (10c), which is arranged in a position opposite the section where the gas is compressed in the pump chamber (10), wherein the exhaust-side opening (51) communicates with the outside of the pump chamber (10) in a front section where the compression ratio of the gas is maximized by the claws of the two rotors (30a, 30B), and an exhaust opening (52) in a rear section, which is connected to the claws of the two rotors (30a, 30B) to expel the gas outwards from the pump chamber (10), including a stage in which the compression ratio of the gas is maximized compared to the previous stage, wherein the outlet opening is connected to the outside of the pump chamber (10) to maximize the compression ratio of the gas, and the exhaust opening (51) of the front section is closed by the rotor (30a, 30B); characterized in that, with the pump chamber body section (100) provided by the cylinder section (10a) and the end wall sections (10b, 10c) arranged on both end faces of the cylinder section (10a) to form the pump chamber (10), and the two rotors (30a, 30B) arranged at one end of each of the two rotating shafts (20A, 20B) and supported in a cantilevered state between the two rotors (30a, 30B) and a bearing section body section (200) which is provided with a bearing section supporting the two rotating shafts (20A, 20B), a gap (60) for cooling is formed, whereby the pump body has a split structural arrangement.

Description

Technical area

[0001] The present invention relates to a claw pump having a pump chamber having a cross-sectional shape in which a part of two circles is superimposed, and two rotors having hook-shaped claws for compressing and discharging the sucked-in gas are arranged.

[0002] JP 2011-38476A discloses a conventional claw pump, in which the cylinder forming the pump chamber has a side plate closing one end of the cylinder and another side plate closing the other end of the cylinder. Two rotating shafts are arranged in the cylinder, parallel to each other and rotating in opposite directions at the same speed. Each of the two rotating shafts is integrally mounted and arranged in the cylinder. Two rotors formed with hook-shaped claws mesh without contact to compress the sucked-in gas. A rotation drive device that drives the two rotors via the two rotating shafts in rotation. An inlet port communicating with the part of the pump chamber in which the gas in the cylinder is not compressed is discharged from both sides via the end face of the cylinder.and an exhaust air opening is arranged on both the side plate of one side and the side plate of the other side, which opens into a part of the pump chamber in which the gas in the cylinder is compressed.

[0003] According to this conventional claw pump, the intake port area can be doubled to reduce the ventilation resistance of the exhaust air, thus improving exhaust efficiency. As a result, pump performance can be improved and the degree of design freedom can be further increased. This effect is more effective when used in areas with low vacuum levels.

[0004] DE 19819 538 C 2 discloses a pump with a pump chamber formed in a housing, which has a suction port and a pressure port, and with two three-bladed rotors that rotate in opposite directions around parallel, offset axes in the pump chamber (18) and mesh without contact. The rotors form separate rows of variable volume with the peripheral wall of the pump chamber and with each other to simultaneously generate pressure and negative pressure during their rotation. The pump chamber has a charging port.

[0005] DE 10 2018 203 992 A1 discloses a rotary piston engine comprising a housing spatially defining a working chamber, a suction port for conducting gas into the working chamber, a pressure port for conducting the gas out of the working chamber, and a rotor assembly. The rotor assembly comprises a first rotor rotatably arranged in a first working sub-chamber, and a second rotor cooperating with the first rotor and rotatably arranged in a second working sub-chamber. Furthermore, the rotary piston engine comprises a ventilation duct formed in the housing, which adjoins the working chamber via a ventilation duct opening and is designed to temporarily introduce air into the working chamber. The ventilation duct opening is open at least in some areas during a compression phase.

[0006] The problem to be solved with the claw pump is that when the vacuum pump is used in a high vacuum range, where the ultimate vacuum is closer to absolute vacuum, the pump chamber will overheat, making it difficult to improve the pump efficiency. This means that when the claw pump is used in a high vacuum range, the pressure in the pump chamber must be reduced below the external pressure (e.g., atmospheric pressure) to allow the exhaust air discharged from the exhaust port to flow back. Then, the returning exhaust air, which is originally at a high temperature, is heated by compression in the pump chamber and expelled. After flowing into the pump chamber, it is recompressed and heated by the backflow, further overheating the pump chamber.When the pump chamber overheats, thermal expansion causes the rotating rotors and rotors to interfere with each other and with components such as the cylinder that forms the pump chamber, resulting in failure. To prevent this, it is necessary to increase the clearance between the components, which does not improve pump performance.

[0007] Therefore, it is an object of the present invention to provide a claw pump as a vacuum pump which can prevent overheating of the pump chamber and improve the efficiency of the pump even when used in a region with a high degree of vacuum.

[0008] The present invention provides the following structure to achieve the stated object. Independent claim 1 defines the invention. Dependent claims 2 to 9 specify embodiments according to the invention.

[0009] The claw pump according to the present invention is a claw pump with an open exhaust-side opening, in which the cylinder section is designed to form a pump chamber with a cross-sectional shape in which a part of two circles overlaps, wherein an end wall section arranged on one end face of the cylinder section and another end wall section arranged on the other end face of the cylinder section are arranged, two parallel rotating shafts are arranged in the pump chamber and rotate in opposite directions at the same speed, wherein the two rotating shafts arranged in the pump chamber each have two rotators formed with hook-shaped claws, by which the sucked gas can be compressed and discharged by contactless rotation,wherein an exhaust-side opening is arranged on at least one end wall section and the other end wall section at a position opposite to the section where the gas is compressed in the pump chamber, wherein the exhaust-side opening communicates with the outside of the pump chamber in a front section in which the compression ratio of the gas is maximized by the claws of the two rotors, wherein an exhaust opening is arranged in the rear section and communicates with the claws of the two rotors to expel the gas to the outside of the pump chamber, including a stage in which the compression ratio of the gas is maximized compared to the previous stage, wherein the outlet opening communicates with the outside of the pump chamber to maximize the compression ratio of the gas, and the front vent opening is closed by the rotor. Furthermore, between the pump chamber body section,which is provided by a cylinder portion and end wall portions arranged on both end surfaces of the cylinder portion to form the pump chamber, and a bearing portion body portion arranged to support the two rotating shafts, so that the two rotors are arranged at one end of the two rotating shafts and are cantilevered, a gap for cooling is formed, whereby the pump body has a split structural arrangement.

[0010] Furthermore, according to an embodiment of the present invention, the claw pump may be characterized in that the front ventilation opening is arranged on one end wall section, and the rear exhaust air opening is arranged on the other end wall section.

[0011] Furthermore, according to an embodiment of the present invention, the claw pump can be characterized in that the two rotors are each arranged at one end of the rotary shaft and are cantilevered, wherein the end wall section is located on the side of the bearing section that supports the two rotary shafts.

[0012] Further, according to one embodiment of the present invention, the claw pump may be characterized in that, in view of an overlapping state in the extending direction of the rotation shaft axis, the front vent and the rear exhaust port are arranged in a separate form in which they do not overlap. Further, according to one embodiment of the present invention, the claw pump may be characterized in that, in view of an overlapping state in the extending direction of the rotation shaft axis, the front vent and the rear exhaust port are arranged in a form formed by assuming the division of a virtual exhaust-side port.

[0013] Further, according to an embodiment of the present invention, the claw pump may be characterized in that, in view of an overlapping state in the extending direction of the rotary shaft axis, the front vent port and the rear exhaust port are arranged to overlap at a part of the lower exhaust port on the low side of the compression ratio.

[0014] Further, according to an embodiment of the present invention, the claw pump may be characterized in that, in view of an overlapping state in the extending direction of the rotary shaft axis, the front vent and the rear exhaust vent are arranged so that the boundary lines forming the edge on the side where the compression ratio of the two is low overlap in the same shape.Further, according to an embodiment of the present invention, the claw pump may be characterized in that the front vent and the rear exhaust port are arranged in a form in which the front vent and the rear exhaust port are divided such that, in view of an overlapping state in the extending direction of the rotation shaft axis, the front vent and the rear exhaust port are arranged in a separated non-overlapping state at either one end wall portion or the other end wall portion.

[0015] Furthermore, according to an embodiment of the present invention, the claw pump may be characterized in that the two rotors are arranged at one end of the rotary shaft and are cantilevered, wherein both the front ventilation opening and the rear exhaust opening are arranged on the one end wall portion which is on the side opposite to the end wall portion which is arranged on the side of the bearing portion which supports the two rotary shafts.

[0016] The claw pump according to the present invention enables, even when the vacuum pump is used in a high degree of vacuum, overheating of the pump chamber to be prevented and the pump efficiency to be significantly improved, which brings about a particularly advantageous effect.

[0017] A brief description of the characters follows. [ Fig. 1] is a sectional view showing the main part of an embodiment of the claw pump according to the present invention. [ Fig. 2] is a perspective view of the overall appearance of an embodiment of the claw pump according to the present invention. [ Fig. 3] is an exploded view of an embodiment of the claw pump according to the present invention. [ Fig. 4] is a perspective view of an element (cylinder housing and side plate) forming a pump chamber. [ Fig. 5] is a front view (a) of a side plate and a front view (b) of a cylinder housing, seen from the direction of arrow A (see Fig. 4). [ Fig. 6] is a front view showing an embodiment in which the exhaust side opening portion divided into the front vent port (solid line) and the rear exhaust port (dashed line) are superimposed in the axial direction of the rotary shaft. [ Fig. 7] is an operation diagram ((a), (b) and (c) of the three states with respect to the rotation position) of an embodiment with respect to the positional relationships between both rotors during the rotation operation, the front vent and the rear exhaust vent. [ Fig. 8] is an explanatory drawing showing the embodiment of the articulated type of exhaust side opening. [ Fig. 9] is an explanatory drawing showing the embodiment of the split type of the exhaust side opening. [ Fig. 10] is an explanatory drawing showing the embodiment of the overlapping type of the exhaust side opening. [ Fig. 11] is an explanatory drawing showing the embodiment of the type of exhaust side opening corresponding to the boundary area. [ Fig. 12] is a perspective view showing the arrangement of a divided exhaust-side opening portion (front vent and rear exhaust opening) on ​​a surface of the side plate of an embodiment. [ Fig. 13] is a side view with a cross section of an embodiment with a cooling gas flow path of the claw pump according to the present invention. [ Fig. 14] is a perspective view with a side view of an embodiment of a claw pump according to the present invention.

[0018] An embodiment of the claw pump according to the present invention will be described below with reference to the accompanying figures ( Fig. 1 to 7) are described in more detail.

[0019] As in Fig. 1 and Fig. 3, in the claw pump according to the present invention, a cylinder portion 10 a and an end wall portion 10 b arranged on an end surface of the cylinder portion 10 a are arranged to form a pump chamber 10 (see Fig. 3 and the like) having a cross-sectional shape in which a part of two circles overlaps and the other end wall portion 10 c is arranged on the other end surface of the cylinder portion 10 a.

[0020] Furthermore, as in Fig. 3 and the like, two rotating shafts 20A and 20B are arranged in parallel in the pump chamber 10, rotating in opposite directions at the same speed. In the present embodiment, gears 21A (drive-side gear) and 21B (driven-side gear) are integrally fixed and arranged on both rotating shafts 20A and 20B. The two pairs of gears 21A and 21B mesh in the gear housing 45 arranged in the bearing portion body portion 200.

[0021] As also in Fig. 3, two rotors 30 A and 30 B are arranged on the two rotating shafts 20 A and 20 B and housed in the pump chamber 10, wherein they have claw portions formed in a hook shape to rotate in a mutually non-contact state and can compress and discharge the sucked gas.

[0022] As shown in each figure, the exhaust-side opening portion 50 is opened at least in part of the end wall portion 10b of one side and the end wall portion 10c of the other side, and is arranged at a position in the pump chamber 10 facing the part where the gas is compressed. As a result, a claw pump, which is a type of biaxial rotary pump, is constructed. Reference numeral 15 denotes a suction port, which is opened and arranged at a position in the pump chamber 10 facing a region where the gas is not compressed (in this embodiment, a wall portion constituting the cylinder portion 10a).

[0023] In the claw pump according to the present invention, an exhaust side opening portion 50 is arranged in which a front vent port 51 communicates with the outside portion of the pump chamber 10 in the front portion in which the compression ratio of gas is maximized by the claws of the two rotors 30A and 30B, and a rear exhaust port 52 is arranged which communicates with the claws of the two rotors 30A and 30B to discharge the gas to the outside portion of the pump chamber 10, including a stage in which the compression ratio of the gas is more maximized compared to the previous stage.

[0024] According to the claw pump of the present invention, even when the vacuum pump is used in a high vacuum range where the ultimate vacuum is closer to absolute vacuum, the pump chamber can be prevented from overheating, and the efficiency of the pump can be significantly improved. That is, the exhaust-side opening portion 50 consists of a front vent 51 and a rear exhaust 52, which are separately opened and arranged. Therefore, when used at a high degree of vacuum, the non-overheated outside air is sucked into the front vent 51, and since the back gas flow can be reduced at the rear exhaust 52 as in the conventional case, it is possible to prevent overheating of the pump chamber.

[0025] That is, the claw pump according to the present invention can be designed to have a negative pressure even in a part where compression is performed within the pump chamber when used in a region where the vacuum degree is higher than a certain level, and to draw in superheated outside air (e.g., cooling air at atmospheric pressure at room temperature) by opening the front vent 51. Therefore, it is possible to prevent or suppress the backflow of the superheated gas (e.g., air) after the rear exhaust vent 52 is opened, and it is possible to suppress an increase in the internal temperature of the pump chamber. That is, the structure including the front vent 51 is the secondary cooling intake mechanism.In this way, secondary cooling is achieved, and by sucking in the outside air (cooling air) inside the pump chamber 10, the apparent air volume is equal to the amount of return air, so the performance does not change and the internal temperature of the pump chamber 10 can be reduced. Therefore, overheating of the pump chamber 10 can be suppressed without losing the energy-saving property, which is an advantage of the claw pump, on the high vacuum side, and the pumping performance can be remarkably improved.

[0026] It should be noted that it would be conceivable to dispose the vent, which opens to the part where compression is performed within the pump chamber 10 and communicates with the outside in a situation where the compression ratio is low, which is the initial stage when compression of the pump cycle begins, in a peripheral wall portion of the cylinder portion 10a. However, if air is sucked through a vent that opens at such an early stage of compression, the amount of air to be treated may increase excessively, and power consumption may increase.

[0027] Furthermore, in the Fig. 1 to 7 shown embodiments, as in Fig. 3 to 5, the pump chamber 10 is formed by a cylinder structural wall consisting of a cylinder casing 11 in which a cylinder portion 10a and one end wall portion 10b are integrally arranged, and a side plate 12 arranged on the other end wall portion 10c. In this embodiment, the pump chamber 10 is mainly formed by a structure of two assembled components, but the present invention is of course not limited thereto, and for example, the cylinder portion 10a, the end wall portion 10b, and the other end wall portion 10c may be mainly formed by three divided members.

[0028] Furthermore, according to the present invention, the two rotors 30 A and 30 B are not limited to a form in which they are cantilevered in the bearings, but the structure is also applicable to a claw pump in which the rotating shafts 20 A and 20 B are rotatably supported at both ends.

[0029] Furthermore, in this embodiment, as shown in the Fig. 1 to 7, the front vent 51 is arranged on one end wall portion 10b, and the rear exhaust vent 52 is arranged on the other end wall portion 10c. This means that both pairs of end wall portions 10b and 10c have openings that communicate with the outside air (atmosphere in this embodiment) outside the pump chamber. Accordingly, the front vent 51 and the rear exhaust vent 52 can be appropriately and easily provided in a suitable shape and at a suitable position. Therefore, the degree of freedom in designing the claw pump can be appropriately increased according to the required performance.

[0030] Next, a mechanism that can prevent the pump chamber 10 from being overheated by the claw pump of the present embodiment will be described in detail below.

[0031] In a conventional claw pump, when the exhaust port is opened at a certain degree of vacuum or higher, a negative pressure exists inside the pump chamber, and a backflow of exhaust air (for example, air at atmospheric pressure) is generated from the exhaust port. That is, in the conventional claw pump, the high-temperature air (exhaust air) can be trapped inside the muffler connected to the exhaust port (the space enclosing the exhaust pipe 55 (see Fig. 13)), backflow from the exhaust port, which was the main cause of the temperature rise inside the pump chamber. Therefore, the prior art adopted a method of increasing the compression ratio of the exhaust air through the shape of the exhaust port as a method to reduce the amount of backflow air. In other words, the area of ​​the exhaust port was made so small that the exhaust port would not open until the compression ratio of the exhaust air was higher than a predetermined value. The higher the compression ratio is set, the more effectively the backflow is prevented, but when the load is on the low vacuum side, the power increase becomes large, and the usable vacuum degree range is limited.That is to say, if the area of ​​the exhaust port is reduced, the ventilation resistance of the exhaust air becomes large when it is used in a low vacuum area, so a large amount of energy is required and the energy consumption increases.

[0032] On the other hand, in the claw pump of the present embodiment, when used in a range (for example, in the range of 60 to 95 kPa) where a predetermined high vacuum is generated so that a negative pressure is generated even in a portion where compression is performed in the pump chamber 10, the secondary cooling air intake is performed through the secondary cooling air intake port (front vent port 51) on the cylinder housing 11 side (end wall portion 10 b of one side), and the pump is exhausted from the exhaust port (rear exhaust port 52) ​​on the side plate 12 side (end wall portion 10 c of the other side).That is, the front vent 51, which is an opening on the side of one end wall portion 10b, is arranged in a form communicating with the outside portion when the compression ratio is lower than or equal to the compression ratio of the rear exhaust port 52, which is the opening of the other end wall portion 10c. According to the claw pump of the present embodiment, when a predetermined high vacuum (e.g., 80 kPa or more) is created, the pump chamber 10 has a compression ratio lower than the final compression ratio in a predetermined range, and the negative pressure is also maintained at the location where internal compression is performed. During this phase, the front vent 51 is opened to communicate with the outside air (e.g., atmospheric pressure air), and secondary cooling air intake occurs.Thereafter, the intake cooling air is added and compressed to the final compression ratio, and the air is discharged from the rear exhaust port 52. That is, in the phase where the rear exhaust port 52 is opened and the exhaust air is finally discharged, the negative pressure in the compressed part within the pump chamber 10 is eliminated because the cooling air is sucked in, and in the subsequent discharge process, backflow at the rear exhaust port 52 is prevented or suppressed. As a result, overheating of the pump chamber 10 can be controlled, and it has been confirmed in the embodiments that the temperature rise to approximately 100°C is controllable and the pump efficiency can be improved.

[0033] The following is a summary of the Fig. 1 to 6, the exhaust air process that can prevent overheating of the pump chamber 10 is based on Fig. 7 described in detail. In the phase of Fig. 7 (a), both the front vent 51 and the rear exhaust 52 are closed by one of the rotors 30A. That is, the large-diameter portions of the main body of one of the rotors 30A are in an overlapping state, and both the front vent 51 and the rear exhaust 52 are closed. Therefore, at this stage (section), neither gas discharge nor intake occurs with respect to the compression position in the pump chamber 10.

[0034] In the phase of Fig. 7 (b), the front vent 51 is opened and the rear exhaust vent 52 is closed by a rotor 30A. That is, only the rear exhaust vent 52 is blocked by the large diameter portion of the main body of the rotor 30A of one side.

[0035] The front vent 51 of the present embodiment communicates with the compression ratio between 2.0 and 2.4, which is the compression point in the pump chamber 10. Then, as described above, the front vent 51 functions as a secondary intake port for cooling air drawn in as outside air when the compression-performing portion of the pump chamber 10 is under negative pressure.

[0036] Furthermore, the front ventilation opening 51 of the present embodiment is formed by a groove portion 51a (see Fig. 3 and the like) by a through-hole 51b extending through the groove portion 51a, and by opening even a part of the groove portion 51a, continuous communication with the outside can be achieved through the through-hole 51b. That is, it is composed of a groove portion 51a located within the plate thickness range of the element and a through-hole portion 51b formed by penetrating the groove portion 51a to communicate with the outside. The through-hole portion 51b of the present embodiment is formed in an L-shaped curved shape (see Fig. 1 and the like) to open downward to the outside. Furthermore, the opening facing the outside of the through-hole portion 51b is circular, and, for example, a pipe or the like may be connected as a connecting portion. Then, if a pipe can be connected to the circular opening as a continuous passage, the area where the front vent opening 51 is open to the outside can be selectively moved to a position away from the rear exhaust opening 52, and more gas such as low-temperature air can be sucked in.

[0037] Furthermore, the front vent opening 51 can function as an exhaust air opening during operation at a low vacuum level if, as in Fig. 7(b). That is, until the interior of the pump chamber 10 has a predetermined high degree of vacuum, the part where compression is performed within the pump chamber 10 has no negative pressure, and in this situation, the compressed gas (e.g., air) is released and is also discharged from this front vent 51. As a result, at this time, the front vent 51 becomes a front exhaust vent. Accordingly, power consumption can be suppressed because the ventilation resistance of the exhaust air can be reduced.

[0038] In the phase of Fig. 7(c), the rear exhaust port 52 is opened, and the front vent 51 is closed by the one-side rotor 30A. This means that only the front vent 51 side is closed by the main body including the claw portion of the one-side rotor 30A. Further, the small-diameter portion of the main body of one rotor 30A is positioned so that the one rotor 30A and the rear exhaust port 52 do not overlap, and the rear exhaust port 52 is in an open state. Then, in the portion inside the pump chamber 10 communicating with the opened rear exhaust port 52, compression occurs, the outside air is sucked in through the front vent 51 and cooled, the compression ratio increases, and since the pressure is higher than that of the outside air, the rear exhaust port 52 is properly discharged without causing backflow.The rear exhaust port 52 of the present embodiment is the section where compression occurs in the pump chamber 10, and the compression ratio, for example, 2.4, and even more than 3.0, is communicated in the section. Therefore, as described above, the pumping performance can be significantly improved. Furthermore, in the present embodiment, as shown in FIG. Fig. 3 and the like, two rotors 30A and 30B are cantilevered at one end of two corresponding rotary shafts 20A and 20B, respectively, and the end wall portion 10b of one side is located on the side of the bearing portion 40 supporting the two rotary shafts 20A and 20B. With this structure, a simpler cantilevered claw pump with fewer parts is properly configured.

[0039] Fig. Figure 8 shows a first example of the exhaust air side opening 50, a configuration which is used in the embodiments described above (see Fig. 1 to 7) to make the execution scheme more understandable, in addition to the enlargement compared to Fig. 1 to 7, the open space is indicated by hatching. This means that in this first example, the front ventilation opening 51 and the rear exhaust opening 52 are arranged in a separated form so as not to overlap in view of an overlapping state in the extending direction of the rotating shafts 20A and 20B. This means that the front ventilation opening 51 and the rear exhaust opening 52 are arranged in a divided form at a predetermined small distance from each other so as not to overlap. As a result, as in this case in Fig. 7 (b), the continuity of the exhaust side opening 50 consisting of the front ventilation opening 51 and the rear exhaust opening 52 is interrupted for a moment.

[0040] Fig. 9 shows a second example of the exhaust-side opening 50, in which the front vent 51 and the rear exhaust vent 52 are arranged in a shape formed by dividing a virtual exhaust-side opening 50 in view of an overlapping state in the extending direction of the axes of the rotating shafts 20A and 20B. That is, the front vent 51 and the rear exhaust vent 52 are arranged in a shape formed by dividing by the arrangement in the divided form of a virtual exhaust-side opening 50.

[0041] Fig. 10 shows a third example of the exhaust-side opening 50 in which the front ventilation opening 51 and the rear exhaust opening 52 are both arranged to overlap in a part of the rear exhaust opening 52 on the lower compression ratio side in view of an overlapping state in the extending direction of the axes of the rotating shafts 20A and 20B.

[0042] Fig. 11 shows a fourth example of the exhaust-side opening 50 in which the front vent 51 and the rear exhaust 52 overlap each other in the extending direction of the axes of the rotating shafts 20A and 20B, and the boundary line 50a forming the edge on the side where the compression ratio of the two is low is arranged to overlap in an identical shape.

[0043] In the above embodiment of the exhaust-side opening 50, the smaller the opening area of ​​the rear exhaust opening 52, the better the performance of the claw pump that generates a high negative pressure. Furthermore, the larger the opening area of ​​the front vent 51 and the rear exhaust opening 52, the more the performance of the claw pump that processes a larger air volume can be improved.

[0044] Furthermore, in the present invention, as in Fig. 12, both the front vent 51 and the rear exhaust vent 52 are arranged in a split form so as not to overlap in view of an overlapping state in the extending direction of the rotating shaft axes 20A and 20B, the two rotors 30A and 30B are cantilevered, and both the front vent 51 and the rear exhaust vent 52 may be configured to be arranged on one end wall portion 10b on the side of the bearing 40 that supports the two rotating shafts 20A and 20B and on the other end wall portion 10c positioned on the opposite side.

[0045] As a result, the front vent 51 and the rear exhaust vent 52 can be rationally arranged on only one surface of the end wall portion to design a suitable shape according to the usage conditions, including the relationship with other devices, and the degree of freedom in design can be increased. That is, since there is a predetermined distance between the front vent 51 and the rear exhaust vent 52, separation of the two is possible, and as shown in Fig. As shown in Figure 12, the outward openings of the vent 51 and the exhaust vent 52 (the opening located above the exhaust pipe 55) can be separated. Therefore, the front vent 51 cannot suck in superheated gas, and the performance of the claw pump can be increased as described above.

[0046] Note that the claw pump of the present invention is not limited to the above-mentioned embodiments, and forms such as the front vent 51 and the rear exhaust vent 52 are arranged only on the end wall portion 10b of one side, the front vent 51 and the rear exhaust vent 52 are arranged on both an end wall portion 10b and an end wall portion 10c, the front vent 51 is arranged on both end wall portions and the rear exhaust vent 52 is arranged on one side of the end wall portion, the front vent 51 is arranged on one side of the end wall portion and the rear exhaust vent 52 is arranged on both end wall portions. These forms can be appropriately and selectively adopted according to various usage conditions.In the case where the front vent 51 and the rear exhaust vent 52 are arranged on both end wall portions, the size, shape, or a combination thereof can be appropriately and selectively designed according to the usage conditions, and needless to say, they do not need to have the same shape.

[0047] Next, a cooling mode relating to the exterior of the claw pump of this embodiment will be described with reference to Fig. 13 and Fig. 14 described.

[0048] The reference numeral 100 refers to the pump chamber body portion, wherein this pump chamber body portion 100 has the end wall portions 10 b and 10 c arranged, which are respectively arranged on the cylinder portion 10 a and on the two end sides of the cylinder portion 10 a to form the pump chamber 10.

[0049] Reference numeral 200 denotes a bearing section body, wherein two rotors 30A (drive-side rotor) and 30B (drive-side rotor) are arranged on the bearing section body 200 at one end of two rotating shafts 20A (drive-side rotating shaft) and 20B (drive-side rotating shaft), respectively. The rotating shafts 20A, 20B are cantilevered in the bearing section 40. The pump body is composed of this bearing section body 200 and the pump chamber body 100.

[0050] The claw pump according to the present invention has a pump chamber body portion 100 and a bearing portion body portion 200 so that a cooling gap 60 is formed between the pump chamber body portion 100 and the bearing portion body portion 200, wherein the pump main body is arranged in a split structure.

[0051] With the rotary pump according to the present invention, it is possible to achieve particular advantages by reducing the transfer of heat generated by the drive to the bearing section body portion 200 and extending the service life of functional parts such as the bearing 40 and the like. This means that according to the present invention, heat conduction can be minimized by separating the pump chamber body 100 and the bearing section body 200. Furthermore, cooling air can flow between the pump chamber body 100 and the bearing section body 200, heat transfer can be controlled, and cooling can be promoted by heat dissipation. As a result, the temperature rise of the bearing section body portion 200 can be controlled and the service life of the functional component can be extended.

[0052] The functional component is a component that includes the bearing 41 and the oil seal 42 and is treated as a consumable component. Extending the service life of these functional parts can reduce operating costs.

[0053] Furthermore, in the present embodiment, as shown in the Fig. 1 and Fig. 2, the columnar connecting sections 101 and 201 (see Fig. 1 to 3) are arranged for connecting so that they are paired at both the pump chamber body portion 100 and the bearing portion body portion 200. For this connection, four pairs of columnar connecting portions 101 and 201 are arranged, and in the present embodiment, as shown in Fig. 3 and the like, the columnar connecting portions 101 and 201 are arranged at the four corners of the body. Thus, the pump chamber body portion 100 and the bearing portion body portion 200 can be stably connected. The fastening means for connecting in this embodiment is a screw connection using screws. Incidentally, the present invention is not limited to the present embodiment, and the shape of the portion in which the cooling gap 60 is formed may be formed into an integral structure. In the case of manufacturing by the casting method, the cooling gap 60 may be formed by, for example, the core.

[0054] In addition, in this embodiment, cooling air (see arrow in Fig. 13) by fan blades 75 which are attached to the coupling section 73 (see Fig. 2) connecting the rotation shaft 20 A and the drive shaft 71 of the drive motor 70, are integrally fixed and arranged, and as shown in Fig. As shown in Figure 13, a fan guide portion 80 is arranged to guide the cooling air flow so that the cooling air generated by the rotation of the fan blades 75 flows onto the surface of the pump chamber body portion 100 to cool the pump chamber 10. This allows the cooling air to be efficiently applied to the surface of the pump chamber body 100, and the cooling performance can be improved.

[0055] Further, in the present embodiment, cooling air is blown upward from the bottom of the pump chamber body portion 100 to the fan guide portion 80 to flow over the surfaces of both end wall portions 10 b and 10 c of the pump chamber body portion 100, and a bottom air duct 81 forming a passage at the bottom of the bearing portion body portion 200 and the pump chamber body portion 100 is arranged to guide the flow of the cooling air.

[0056] Accordingly, both end wall sections 10b and 10c of the pump chamber body section 100 can be cooled simultaneously, and since the exhaust pipe 55 can also be cooled, efficient cooling can be achieved. In addition, a rational flow path that does not stir up dust on the floor of the cooling air can be configured accordingly.

[0057] Furthermore, as in Fig. 13, the fan guide portion 80 of the present embodiment covers the entire coupling portion 73 (see Fig. 2), in which the pump chamber body portion 100, the bearing portion body portion 200, and the fan blade 75 are integrally fixed and arranged, with a box-shaped cover 90 formed of a plate-shaped member. That is, a suction port 91 for introducing cooling air is arranged near the fan blade 75 of the box-shaped cover 90. In order for the cooling air discharged from the fan blade 75 to flow smoothly toward the side of the pump body portion 100 and the bearing portion body portion 200, the bottom air duct 81, which guides the flow of cooling air, is arranged in a shape curved toward the bottom by plates (wide shape of the duct cross section).To improve cooling performance by increasing the flow velocity of the cooling air flow on the surfaces of the end wall portions 10b and 10c of the pump body portion 100, the flow path of the bottom air channel 81 is narrowed as it approaches the pump chamber body portion 100 (narrow channel cross-sectional shape). An exhaust port 92 and an outlet port 93 are arranged on the upper part of the box-shaped cover 90, so that the cooling air that has passed through the surfaces of both end wall portions 10b and 10c of the pump chamber body portion 100 can be smoothly blown from the bottom to the top. The intake port 91, exhaust port 92, and outlet port 93 of the present embodiment are arranged in a fin shape. According to the cooling structure described above, the claw pump can be reasonably and appropriately configured, and the cooling performance can be improved.Furthermore, in the claw pump according to the present invention, the bottom of the pump chamber 10 is likely to overheat, and a structure in which cooling air is supplied from the bottom can be appropriately formed as described above. Therefore, the pump chamber 10 can be efficiently cooled, the pumping performance can be improved, and the service life of the functional component can be extended, which is a particularly advantageous effect.

[0058] Furthermore, since the front vent 51 is located below the rotating shafts 20A and 20B, it becomes easy to suck in the unheated cooling air, and the interior of the pump chamber 10 can be efficiently cooled. Therefore, the pumping efficiency can be improved.

[0059] Furthermore, in this embodiment, as shown in the Fig. 3 and Fig.As shown in Figure 4, cooling fins 17 and 47 are arranged on the surface of the end wall portion 10b of one side and the wall portion forming the bearing portion 40 and facing the end wall portion 10b, forming the cooling gap. These cooling fins 17 and 47 are arranged in a vertically extending shape and can guide the cooling air flowing from the bottom upward without obstructing the flow, improving cooling efficiency.

[0060] Although various embodiments of the present invention have been described above, the present invention is not limited to the embodiments of the present invention, and it goes without saying that many modifications can be made without departing from the spirit of the invention. List of reference symbols 10 Pump chamber 10 a cylinder section 10 b End wall section of one side 10 c End wall section of the other side 11 Cylinder housing 12 Side plate 15 Gas intake opening 17 cooling fins 20 A rotary shaft (drive-side rotary shaft) 20 B Rotation shaft (output-side rotation shaft) 21 A Gear (drive-side gear) 21 B Gear (output side gear) 30 A rotor (drive-side rotor) 30 B rotor (output-side rotor) 40 shaft bearings 41 warehouses 42 Oil seal 45 Gearbox housing 47 cooling fin 50 Exhaust air side opening section 50 a Limit line that forms the lower limit of the compression ratio 51 front ventilation opening 51 a channel section 51 b Through hole 52 rear exhaust air opening 55 Exhaust pipe 60 cooling gap 70 drive motor 73 Coupling section 75 fan blades 80 Blower guide section 81 floor air duct 90 Box-shaped cover 91 Intake opening 92 Drain opening 93 Drain opening 100 pump chamber bodies 101 Connecting section in column form 200 bearing section body section 201 Connecting section in column form

Claims

[1] Claw pump, comprising a pump chamber (10) with a cross-sectional shape in which parts of two circles overlap, and which has a cylinder section (10a), wherein one end wall section (10b) is arranged on one end face of the cylinder section (10a) and the other end wall section (10c) is arranged on another end face of the cylinder section (10a), in the pump chamber (10) two axes of rotation (20A, 20B) rotating parallel and at the same speed in opposite directions, two claw-shaped rotors (30a, 30B) arranged on each of the two rotation axes (20A, 20B) in the pump chamber (10), which rotate in a non-contact state relative to each other and can compress and discharge the sucked-in gas, and an exhaust-side opening (51) on at least one of the one end wall portion (10b) and the other end wall portion (10c), which is arranged at a position opposite to the portion at which the gas in the pump chamber (10) is compressed, wherein the exhaust-side opening (51) communicates with the outside of the pump chamber (10) in a front portion in which the compression ratio of the gas is maximized by the claws of the two rotors (30a, 30B), and an exhaust port (52) in a rear section communicating with the claws of the two rotors (30a, 30B) to expel the gas to the outside of the pump chamber (10), including a stage in which the compression ratio of the gas is maximized compared to the previous stage, wherein the outlet port communicates with the outside of the pump chamber (10) to maximize the compression ratio of the gas, and the exhaust port (51) of the front section is closed by the rotor (30a, 30B); characterized bythat with the pump chamber body portion (100) provided by the cylinder portion (10a) and the end wall portions (10b, 10c) arranged on both end surfaces of the cylinder portion (10a) to form the pump chamber (10), and the two rotors (30a, 30B) arranged at one end of each of the two rotation shafts (20A, 20B) and supported in a cantilevered state between the two rotors (30a, 30B) and a bearing portion body portion (200) provided with a bearing portion supporting the two rotation shafts (20A, 20B), a gap (60) for cooling is formed, whereby the pump body has a split structural arrangement. [2] Claw pump according to claim 1, characterized by that the front ventilation opening (51) is arranged on one end wall section (10b) and the rear exhaust air opening (52) is arranged on the other end wall section (10c). [3] Claw pump according to claim 2, characterized bythat the front ventilation opening (51) and the rear exhaust opening (52) are both arranged in a split form so as not to overlap in view of an overlapping state in the extending direction of the rotation shaft axis. [4] Claw pump according to claim 2, characterized by that the front ventilation opening (51) and the rear exhaust air opening (52) are arranged in a shape formed by assuming the division of a virtual exhaust air side opening in view of an overlapping state in the extension direction of the rotation shaft axis. [5] Claw pump according to claim 2, characterized by that the front ventilation opening (51) and the rear exhaust opening (52) are arranged to overlap at a part of the lower exhaust opening on the low side of the compression ratio in view of an overlapping state in the extending direction of the rotary shaft axis. [6] Claw pump according to claim 2, characterized by that the front ventilation opening (51) and the rear exhaust air opening (52) are arranged in view of an overlapping state in the extending direction of the rotary shaft axis so that the compression ratio of the two at the boundary lines forming the edge of the low side overlap in the same shape. [7] Claw pump according to any one of claims 1 to 6, characterized by that the two rotors (30a, 30B) are arranged at one end of the rotary shaft (20A, 20B) and are cantilevered, and the one end wall section (10b) is located on the side of the bearing section which supports the two rotary shafts (20A, 20B). [8] Claw pump according to claim 1, characterized byin that the front ventilation opening (51) and the rear exhaust air opening (52) are both arranged in a separate form so as not to overlap in view of an overlapping state in the extending direction of the rotation shaft axis, wherein the front ventilation opening (51) and the rear exhaust air opening (52) are arranged on either one end wall section (10b) or the other end wall section (10c). [9] Claw pump according to claim 8, characterized by in that the two rotors (30a, 30B) are arranged at one end of the rotary shaft (20A, 20B) and are cantilevered, wherein both the front ventilation opening (51) and the rear exhaust opening (52) are arranged on an end wall section (10b) which is located on the side opposite the end wall section (10c) which is located on the side of the bearing section which supports the two rotary shafts (20A, 20B).

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