Pump device

Abstract

This invention provides a pump device that simplifies the structure and suppresses hydraulic pressure amplitude, and also reduces noise or vibration associated with hydraulic pressure amplitude. The pump device includes: a housing (H) defining an inlet (15), an outlet (16), and a receiving chamber (13); and a pump unit (Pu) disposed in the receiving chamber and defining a pump chamber (Pc), which expands and contracts to provide a pumping action to the fluid including an inlet stroke, a pressurization stroke, and an outlet stroke, and the housing includes: an air inlet (27) that opens at a predetermined opening time before the completion of the inlet stroke to introduce air into the pump chamber.

Description

Technical Field

[0001] This invention relates to a pump device for drawing in fluid, pressurizing it, and ejecting it, and more particularly to a pump device comprising an inner rotor and an outer rotor, suitable for use in cylinder blocks of internal combustion engines or fluid machines. Background Technology

[0002] As a conventional pump device, a trochoid pump is known, which includes: a casing having an intake port and an exhaust port; an inner rotor and an outer rotor, which are pump units, housed in the receiving space of the casing; and a pump shaft that rotates integrally with the inner rotor. The trochoid pump pressurizes and supplies engine oil (see, for example, Patent Document 1).

[0003] In the cycloidal pump, the outer rotor rotates in conjunction with the pump shaft and the inner rotor. As a result, the gap (pump chamber) between the inner and outer teeth of the two rotors repeatedly expands and contracts, thereby continuously and repeatedly performing the suction stroke for drawing in working oil and the pressurization and ejection strokes for pressurizing and ejecting the drawn-in working oil.

[0004] During pump operation, especially if the pump shaft rotates at high speed, the suction resistance of the working oil increases, and at the moment the suction stroke is completed, the inside of the pump chamber becomes a negative pressure state. In addition, at the instant the pump chamber connects with the discharge port side after the suction stroke is completed, the working oil in the pump chamber of the previous pressurization and discharge stroke flows backward, and then the backward flow stops and forward flow is generated.

[0005] Due to the aforementioned counter-current and co-current phenomena, the oil pressure in the pump chamber during the pressurization and ejection strokes repeatedly decreases and increases with the rotation of the pump shaft, resulting in increased oil pressure fluctuations (oil pressure amplitude), which in turn leads to noise or vibration. Furthermore, if the negative pressure becomes too large, problems such as impact noise caused by cavitation or rotor corrosion may also occur.

[0006] On the other hand, in order to suppress oil pressure amplitude with the same injection volume, the following method was also considered: using an inner rotor and an outer rotor with multiple teeth to subdivide the injection and increase the number of injections, but this leads to a larger rotor diameter and a larger overall pump size. Moreover, the method of arranging the pump unit in two stages and alternately injecting to increase the number of injections was also considered, but the number of parts increased, leading to higher costs and a larger overall pump size.

[0007] Furthermore, as conventional pump devices, there are oil pump devices or cycloidal pumps that are constructed by dividing the outer rotor or inner rotor into multiple pieces in order to reduce noise (see, for example, Patent Document 2 and Patent Document 3).

[0008] However, these pump units allow backflow of the working oil and do not suppress the increase in oil pressure fluctuations (oil pressure amplitude) caused by the backflow of the working oil.

[0009] [Existing Technical Documents]

[0010] [Patent Literature]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 2018-105291

[0012] [Patent Document 2] Japanese Patent Application Publication No. 2003-293964

[0013] [Patent Document 3] Japanese Patent Application Publication No. 2010-53785 Summary of the Invention

[0014] [The problem the invention aims to solve]

[0015] The present invention was made in view of the above circumstances, and its object is to eliminate the problems of the prior art, etc., and to provide a pump device that simplifies the structure, suppresses oil pressure amplitude, and reduces noise or vibration associated with oil pressure amplitude.

[0016] [Technical means to solve the problem]

[0017] The pump device of the present invention comprises: a housing defining an inlet, an outlet, and a receiving chamber; and a pump unit disposed within the receiving chamber and defining a pump chamber, the pump chamber expanding and contracting to provide a pumping action to the fluid including an inlet stroke, a pressurization stroke, and an outlet stroke. The housing includes an air inlet that opens at a predetermined opening time before the inlet stroke is about to be completed to introduce air into the pump chamber.

[0018] The pump device may also employ the following structure: the air inlet is closed at a predetermined closing time after the suction stroke is completed.

[0019] The pump device may also employ the following structure: the pump unit includes an inner rotor that rotates about a predetermined axis; and an outer rotor that rotates in conjunction with the rotation of the inner rotor.

[0020] The pump device may also employ the following structure: the outer casing has an air inlet hole in the wall portion where it slides on the end faces of the inner and outer rotors.

[0021] The pump device may also employ the following structure: the air inlet is located at a position that is opened and closed by the end face of the inner rotor.

[0022] The pump device may also employ a structure in which the nozzle includes an offset opening region, which is offset to allow the fluid pressurized by the pump chamber to be ejected from the outer peripheral region of the outer rotor away from the inner rotor during a specified period from the start of the pressurization and ejection stroke, and is offset to the outer peripheral region of the outer rotor.

[0023] The pump device may also employ the following structure: the inner rotor and outer rotor are cycloidal rotors with four blades and five segments.

[0024] The pump device may also employ the following structure: when the rotation angle of the inner rotor over the entire range of the suction stroke is set to θ, and the rotation angle of the inner rotor from the opening moment to the completion of the suction stroke is set to Δθa, Δθa is set to the range of 0.08×θ<Δθa<0.12×θ.

[0025] The pump device may also employ the following structure: when the rotation angle of the inner rotor over the entire range of the suction stroke is set as θ, the rotation angle of the inner rotor from the opening moment to the completion of the suction stroke is set as Δθa, and the rotation angle of the inner rotor from the completion of the suction stroke to the closing moment is set as Δθb, Δθa is set to the range of 0.08×θ<Δθa<0.12×θ, and Δθb is set to the range of 0.6×Δθa<Δθb<0.7×Δθa.

[0026] The pump assembly may also employ a structure that includes a check valve that allows only airflow into the pump chamber from the air inlet.

[0027] The pump device may also employ the following structure: the outer casing includes: a bottomed cylindrical outer shell, defining an inlet, an outlet, a connecting wall that engages with the applicable object, and a receiving chamber; and a flat outer casing cover, which is attached to the outer casing to close the receiving chamber, with an air inlet provided on the outer casing cover.

[0028] The pump device may also employ the following structure: the outer casing includes: a bottomed cylindrical outer shell defining a receiving chamber; and a flat outer casing cover defining an inlet, an outlet, and a connecting wall that engages with the applicable object, and is connected to the outer casing to close the receiving chamber, with an air inlet provided in the outer casing.

[0029] [The effects of the invention]

[0030] By adopting the pump device with the aforementioned structure, structural simplification and suppression of oil pressure amplitude can be achieved, as well as a reduction in the accompanying noise or vibration. Attached Figure Description

[0031] Figure 1This is a block diagram illustrating how the pump device of the first embodiment of the present invention can be applied to a system of an applicable object (internal combustion engine).

[0032] Figure 2 An exploded perspective view showing the state in which the pump device of the first embodiment is installed in front of the applicable object (internal combustion engine).

[0033] Figure 3 This is a perspective view of the pump device of the first embodiment viewed from the side opposite to the joint wall that is joined to the applicable object.

[0034] Figure 4 This is a perspective view of the pump device of the first embodiment, viewed from the side of the joint wall that is joined to the applicable object.

[0035] Figure 5 for Figure 3 An exploded perspective view of the pump unit shown.

[0036] Figure 6 for Figure 4 An exploded perspective view of the pump unit shown.

[0037] Figure 7 This is a cross-sectional view of the pump device of the first embodiment cut off by a plane passing through the axis of rotation.

[0038] Figure 8 The diagram shows the relationship between the pump unit (inner rotor and outer rotor) and the suction port and the discharge port of the pump device of the first embodiment, and is a front view with the outer casing removed.

[0039] Figure 9 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the first embodiment.

[0040] Figure 10 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the first embodiment.

[0041] Figure 11 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the first embodiment.

[0042] Figure 12 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the first embodiment.

[0043] Figure 13 A graph illustrating the characteristics of oil pressure amplitude relative to rotational speed in the pump device of the present invention and conventional pump devices.

[0044] Figure 14 This is a front view of the housing included in the pump device according to the second embodiment of the present invention.

[0045] Figure 15 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the second embodiment.

[0046] Figure 16 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the second embodiment.

[0047] Figure 17 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the second embodiment.

[0048] Figure 18 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the second embodiment.

[0049] Figure 19 This is a schematic diagram illustrating the operation of the pump assembly (inner rotor and outer rotor) according to the second embodiment.

[0050] Figure 20 This is a block diagram illustrating how the pump device of the third embodiment of the present invention can be applied to a system of an applicable object (internal combustion engine).

[0051] Figure 21 This is a perspective view of the pump device according to the fourth embodiment of the present invention, viewed from the side opposite to the joint wall that is joined to the applicable object.

[0052] Figure 22 This is a perspective view of the pump device of the fourth embodiment, viewed from the side of the joint wall that is joined to the applicable object.

[0053] Figure 23 This is a cross-sectional view of the pump device of the fourth embodiment cut off by a plane passing through the axis of rotation.

[0054] [Explanation of Symbols]

[0055] E: Internal combustion engine (applicable object)

[0056] M1, M2, M3, M4: Pump units

[0057] S: Axis

[0058] H: Outer shell

[0059] 10, 110, 210: Outer shell (casing)

[0060] 11, 221: Joint wall

[0061] 13, 213: Containment Room

[0062] 15. 224: Suction port

[0063] 16, 116, 225: Spray nozzles

[0064] 116a: Offset opening area

[0065] 20, 220: Outer casing (outer shell)

[0066] 22b, 211b: Inner wall surface (wall of the outer shell)

[0067] 27, 218: Air inlet holes

[0068] Pu: Pump unit

[0069] Pc: Pump chamber

[0070] 40: Inner Rotor

[0071] 42: End face of the inner rotor

[0072] 50: External rotor

[0073] 60: Check valve Detailed Implementation

[0074] The following is a reference to the appendix. Figure 1 The embodiments of the present invention will be described below.

[0075] The pump device M1 of the first embodiment is applicable to an internal combustion engine E.

[0076] Here, internal combustion engine E is like Figure 1 and Figure 2 As shown, it includes an engine body 1 and an oil pan 2 attached to the lower part of the engine body 1. The engine body 1 includes a mating surface 3 for engaging the pump device M1, a cylindrical fitting recess 4, an oil outlet passage 5, an oil inlet passage 6, and three screw holes 7 for screwing in the screw B, etc.

[0077] Pump unit M1 such as Figures 3 to 6 As shown, it includes an outer housing 10 and a housing cover 20 as the outer housing H, a rotating shaft 30 centered on a predetermined axis S, an inner rotor 40 and an outer rotor 50 as the pump unit Pu, and screws b that fasten the housing cover 20 to the outer housing 10.

[0078] The outer shell 10 is formed into a bottomed cylindrical shape using metal materials such as steel, cast iron, sintered steel, and aluminum alloy, such as... Figure 5 and Figure 6 As shown, it includes a joint wall 11, an outer peripheral wall 12, a receiving chamber 13, an insert part 14, an intake port 15, an exhaust port 16, a bearing hole 17, three through holes 18 and a screw hole 19.

[0079] Joint wall 11 Figure 7As shown, a flat wall is formed perpendicular to the axis S, defining the outer wall surface 11a of the joint surface 3 that is joined to the engine body 1, and the inner wall surface 11b of the end face 41 and end face 51 of the pump supply unit Pu that slide closely together.

[0080] The outer peripheral wall 12 protrudes cylindrically from the outer edge region of the joint wall 11 along the axis S, defining an annular end face 12a.

[0081] The containment chamber 13 is a space defined by the connecting wall 11 and the outer peripheral wall 12, which rotatably contains the pump unit Pu.

[0082] Moreover, containment chamber 13, such as Figure 8 As shown, it includes an arc surface 13a in the form of a cylinder, the cylinder surface being centered on an axis S1 that is parallel to and offset from the axis S.

[0083] The arc surface 13a slides freely to support the outer peripheral surface 53 of the outer rotor 50, which is part of the pump unit Pu. Moreover, the inner edge of the arc surface 13a also functions as a fitting recess for fitting the fitting protrusion 22 of the outer casing 20.

[0084] The insertion portion 14 is formed as a cylindrical shape that protrudes outward from the joint wall 11 in the direction of axis S and is centered on axis S, and is closely fitted into the fitting recess 4 of the engine body 1.

[0085] Inlet 15 Figure 4 , Figure 6 , Figure 8 As shown, the mating wall 11 is formed through the outer wall surface 11a to the inner wall surface 11b in a generally crescent-shaped outline. In addition, when the pump device M1 is engaged with the mating surface 3 of the engine body 1, the working oil guided from the outflow passage 5 is drawn into the pump chamber Pc through the suction port 15.

[0086] Spray nozzle 16 Figure 4 , Figure 6 , Figure 8 As shown, in the region of the mating wall 11 and on the side opposite to the intake port 15 across the insert portion 14, a generally crescent-shaped profile is formed extending from the outer wall surface 11a to the inner wall surface 11b. Furthermore, with the pump device M1 engaged with the mating surface 3 of the engine body 1, the working oil pressurized by the pump chamber Pc is sprayed through the spray outlet 16 into the inflow passage 6.

[0087] The bearing hole 17 is formed into a cylindrical shape centered on the axis S on the inner side of the insertion portion 14 in order to support the one end region 31 of the rotating shaft 30 rotatably.

[0088] Three through holes 18 are provided for the screw B to be screwed into the screw hole 7 of the engine body 1, and are formed in such a way that they pass through from the end face 12a along the axis S to the outer wall surface 11a.

[0089] A screw hole 19 is formed on the end face 12a for screwing in the screw b that attaches the outer cover 20 to the outer cover 10.

[0090] The outer cover 20 is attached to the outer shell 10 to seal the receiving chamber 13 of the outer shell 10, and is formed into a flat plate using materials such as steel, cast iron, sintered steel, and aluminum alloy.

[0091] Additionally, the outer casing 20, as Figures 5 to 7 As shown, it includes a connecting wall 21, a fitting protrusion 22, a bearing hole 23, an annular protrusion 24, three through holes 25, a round hole 26, and an air inlet hole 27.

[0092] The connecting wall 21 is formed as a flat wall perpendicular to the axis S and is tightly connected to the end face 12a of the outer shell 10.

[0093] The fitting protrusion 22, located near the center of the outer casing 20, is formed in the shape of a disk protruding from the mating wall 21 along the axis S1, defining an outer peripheral surface 22a and an inner wall surface 22b. The outer peripheral surface 22a fits into the inner edge of the arc surface 13a of the outer casing 10. The inner wall surface 22b is in close contact with the end faces 42 and 52 of the pump unit Pu.

[0094] The bearing hole 23 is formed into a cylindrical shape centered on the axis S in order to rotatably support the other end region 32 of the rotating shaft 30.

[0095] The annular protrusion 24 around the bearing hole 23 is formed into a cylindrical shape that protrudes outward in the direction of axis S in order to improve mechanical strength.

[0096] The three through holes 25 are for the screw B to be screwed into the screw hole 7 of the engine body 1. At the position corresponding to the three through holes 18 of the outer casing 10, they are formed as circular holes that pass through along the axis S.

[0097] A circular hole 26 is formed near a through hole 25 for the screw b that attaches the outer cover 20 to the outer cover 10 to pass through.

[0098] In order to introduce external air into the pump chamber Pc defined by the pump unit Pu, the air inlet 27 is formed as a circular hole that penetrates along the axis S in the wall portion of the annular protrusion 24 and the area of ​​the inner wall surface 22b where the inner rotor 40 slides.

[0099] In addition, the air inlet 27 is opened by the end face 42 of the inner rotor 40 at a predetermined opening time before the suction stroke of the pump unit Pu is about to be completed, and is closed by the end face 42 of the inner rotor 40 at a predetermined closing time after the suction stroke is completed.

[0100] As described above, the outer casing H includes: a bottomed cylindrical outer casing 10, defining an intake port 15, an exhaust port 16, a mating wall 11 that engages with an internal combustion engine E which is the applicable object, and a housing 13; and a flat outer casing cover 20, which is attached to the outer casing 10 to close the housing 13, and an air inlet 27 is provided on the outer casing cover 20.

[0101] Thus, the air inlet 27 is provided in the housing H in the area opposite to the side that engages with the object, so there are no obstructions on the outside of the air inlet 27, and air (outside air) can be smoothly introduced into the pump chamber Pc.

[0102] The rotating shaft 30 is formed into a cylindrical shape extending along the axis S using materials such as steel. One end region 31 is fitted into the bearing hole 17 of the outer casing 10, and the other end region 32 is fitted into the bearing hole 23 of the outer casing cover 20, and is supported to rotate freely around the axis S.

[0103] Figure 7 In the diagram, the rotating shaft 30 is represented in a simple form that protrudes slightly from the outer casing H along the axis S, with details of the end omitted.

[0104] In fact, the rotating shaft 30 is formed in the other end side region 32 protruding from the outer cover 20, in the case of transmitting the driving force of the driving rotating body of the internal combustion engine, for example, in a manner connected to a passive rotating body such as a gear, sprocket, or pulley; and in the case of transmitting the driving force of the driving rotating body of the electric motor (e.g., rotor, drive shaft), it is formed in a manner connected to the driving rotating body via a transmission member or directly.

[0105] On the other hand, the rotating shaft 30 is formed, for example, in a way that it is directly connected to the driving rotating body, in a region 31 protruding from the joint wall 11 of the outer casing 10, when the driving force of the driving rotating body of the internal combustion engine is transmitted.

[0106] In this embodiment, such as Figure 2 As shown, gear 8 is connected to the other end region 32 and transmits the driving force of the driving rotating body of the internal combustion engine E.

[0107] Pump unit Pu is disposed in housing chamber 13 of housing H, defining pump chamber Pc, which expands and contracts (expands and contracts) to provide pumping action to working oil as a fluid, including suction stroke, pressurization stroke and ejection stroke, and pump unit Pu is configured as a four-bladed, five-section cycloidal rotor including inner rotor 40 and outer rotor 50.

[0108] The inner rotor 40 is an external gear formed from a metal material such as steel or sintered steel, having a tooth profile based on a cycloidal curve. Additionally, the inner rotor 40, as... Figures 5 to 7 As shown, it includes an end face 41 that slides on the inner wall surface 11b of the outer casing 10, an end face 42 that slides on the inner wall surface 22b of the outer casing cover 20, a fitting hole 43 for the rotating shaft 30 to fit into, four protrusions 44 and four recesses 45.

[0109] In addition, the inner rotor 40 rotates integrally with the rotating shaft 30 in the direction of arrow R, with axis S as the center.

[0110] The outer rotor 50 is an internal gear formed from a metal material such as steel or sintered steel, having a tooth profile capable of meshing with the inner rotor 40. Additionally, the outer rotor 50, as... Figures 5 to 7 As shown, it includes an end face 51 that slides on the inner wall surface 11b of the outer casing 10, an end face 52 that slides on the inner wall surface 22b of the outer casing cover 20, a cylindrical outer peripheral surface 53 centered on the axis S1, five protrusions 54 and five recesses 55.

[0111] The outer peripheral surface 53 slides freely in contact with the arc surface 13a of the outer shell 10.

[0112] The five protrusions 54 and the five recesses 55 are formed in such a way that they partially engage with the four protrusions 44 and the four recesses 45 of the inner rotor 40.

[0113] Furthermore, the outer rotor 50 rotates in conjunction with the inner rotor 40, which rotates around axis S, while operating at a slower speed than the inner rotor 40. Figure 8 As shown, it rotates in the same direction as the inner rotor 40 with axis S1 as the center.

[0114] Furthermore, by partially meshing and rotating the inner rotor 40 and the outer rotor 50, a pump chamber Pc that expands and contracts between the two is defined, continuously generating pump action including suction stroke, pressurization stroke, and discharge stroke.

[0115] Next, refer to Figures 9 to 12 The operation of the pump unit M1 will be explained. Furthermore, the sequential operation of the rotating shaft 30 and the inner rotor 40 when rotating counterclockwise (in the direction of arrow R) will be shown. Here, the explanation will focus on the pump chamber Pc defined behind a protrusion 44 (marked with a black dot) of the inner rotor 40 in the direction of rotation R.

[0116] First, such as Figure 9 As shown, when the inner rotor 40 is at a rotation angle θ0, the suction stroke (at the beginning of the suction stroke) begins, inhaling working oil from the suction port 15.

[0117] Next, when the inner rotor 40 rotates to the position of rotation angle θ1 (approximately 90 degrees here), it is in the middle of the process of drawing working oil from the suction port 15 into the pump chamber Pc (suction stroke).

[0118] Next, when the inner rotor 40 rotates to the position of rotation angle θ2 (approximately 150 degrees in this case), it is in the middle of the process of further drawing working oil from the suction port 15 into the pump chamber Pc (suction stroke). Moreover, in this state, although the pump chamber Pc is close to the air inlet hole 27, the end face 42 of the inner rotor 40 blocks the air inlet hole 27.

[0119] Next, as Figure 10 As shown, when the inner rotor 40 rotates to a position with a rotation angle θ3 (approximately 165 degrees in this case), it is in the following state: although it is in the suction stroke where working oil is further drawn from the suction port 15 into the pump chamber Pc, the suction port 15 is compressed and gradually becomes smaller. Moreover, in this state, although the pump chamber Pc is adjacent to the air inlet port 27, the end face 42 of the inner rotor 40 blocks the air inlet port 27.

[0120] Next, when the inner rotor 40 rotates to the position of rotation angle θ4 (approximately 172 degrees in this case), it is just before the suction stroke of drawing working oil from the suction port 15 into the pump chamber Pc is completed, and the suction port 15 is compressed, increasing the passage resistance. Therefore, when the rotating shaft 30 rotates at a particularly high speed, the working oil does not continue to flow into the pump chamber Pc, and the gas environment inside the pump chamber Pc is in a state of high negative pressure.

[0121] Just before the suction stroke is completed, the end face 42 of the inner rotor 40 leaves the air inlet hole 27, opening the air inlet hole 27. Therefore, due to the negative pressure of the pump chamber Pc, outside air begins to be drawn into the pump chamber Pc through the air inlet hole 27.

[0122] Next, when the inner rotor 40 rotates to the position of rotation angle θ5 (approximately 185 degrees in this case), the suction stroke of drawing working oil from the suction port 15 into the pump chamber Pc is approaching completion. The air inlet 27 remains open, and due to the negative pressure in the pump chamber Pc, external air continues to flow into the pump chamber Pc under the action of inertial force. As a result, the negative pressure in the pump chamber Pc decreases.

[0123] Furthermore, such as Figure 11As shown, when the inner rotor 40 rotates to the position of rotation angle θ6 (approximately 192 degrees in this case), the suction port 15 closes and the suction stroke is completed. That is, the completion of the suction stroke is the point in time when the suction port 15 is closed.

[0124] At this point, the air inlet 27 remains open, and the outside air is also flowing into the pump chamber Pc under the influence of inertial force. Up to this point, the negative pressure in the pump chamber Pc has been sufficiently reduced.

[0125] On the other hand, the pump chamber Pc begins to connect with the nozzle 16 through a narrow area, and the working oil in the pump chamber Pc begins to flow towards the nozzle 16 (at the beginning of the pressurization and injection stroke).

[0126] Thus, when the suction stroke is completed and the pressurization and ejection stroke begins, the negative pressure in the pump chamber Pc is eased by the introduced external air, suppressing or preventing the backflow of the working oil in the pump chamber Pc from the previous stroke. Moreover, since the backflow is suppressed or prevented, the pressure rise caused by the subsequent flow is also suppressed or prevented.

[0127] Next, when the inner rotor 40 rotates to the position of rotation angle θ7 (approximately 205 degrees in this case), the air inlet 27 is blocked by the end face 42 of the inner rotor 40. That is, the air inlet 27 is blocked at a predetermined closing time (rotation angle θ7) after the completion of the suction stroke (rotation angle θ6). In addition, the working oil in the pump chamber Pc is pressurized and ejected from the nozzle 16 (pressurization and ejection strokes).

[0128] Next, the inner rotor 40 passes through a position with a rotation angle θ8, as shown below. Figure 12 As shown, the position after rotation angle θ9 and the rotation angle θ 10 Rotate to the position of rotation angle θ 11 The position. During this process, the working oil in the pump chamber Pc is pressurized and continuously ejected from the nozzle 16 (pressurization and ejection stroke). Moreover, at the rotation angle θ 11 Return to the position Figure 9 The position of the rotation angle θ0 shown.

[0129] Here, we focus on one protrusion 44 for explanation, but in reality, the pump chambers Pc defined behind the four protrusions 44 each perform the same action (pumping action). Therefore, during one revolution of the rotating shaft 30, four consecutive suction strokes, pressurization strokes, and ejection strokes are performed.

[0130] In the first embodiment, the opening timing of the air inlet 27 is set to a rotation angle θ4 approximately 20 degrees before the rotation angle θ6 at which the suction stroke is completed.

[0131] Specifically, when the rotation angle (rotation angle θ6 - rotation angle θ0) of the inner rotor 40 throughout the entire range of the suction stroke is set as θ, and the rotation angle (rotation angle θ6 - rotation angle θ4) of the inner rotor 40 from the opening moment (rotation angle θ4) to the completion of the suction stroke (rotation angle θ6) is set as Δθa, then θ = 192 degrees, Δθa = 192 - 172 = 20 degrees, and Δθa = 0.1 × θ.

[0132] Considering the assembly deviation of parts or the allowable angular range for efficient air introduction, Δθa is preferably set to the range of 0.08×θ<Δθa<0.12×θ.

[0133] That is, the rotation angle Δθa of the inner rotor 40 from the opening moment to the completion of the suction stroke is very small relative to the rotation angle θ of the suction stroke range, and the opening moment is set to be earlier than the completion of the suction stroke by about 10% of the rotation angle of the suction stroke range.

[0134] In other words, the opening timing of the air inlet 27 is set just before the suction stroke is about to be completed.

[0135] Furthermore, when the rotation angle (rotation angle θ7 - rotation angle θ6) of the inner rotor 40 from the completion of the intake stroke (rotation angle θ6) to the closing moment of the air inlet 27 (rotation angle θ7) is set as Δθb, it becomes Δθb = 205 - 192 = 13 degrees, and becomes Δθb = 0.65 × Δθa.

[0136] Considering the assembly deviation of parts or the allowable angular range for efficient air introduction, Δθb is preferably set to the range of 0.6×Δθa<Δθb<0.7×Δθa.

[0137] In other words, the timing for closing the air inlet 27 is set to when the outlet 16 begins to connect with the pump chamber Pc after the suction stroke is completed.

[0138] As described above, the pump device M1 according to the first embodiment can alleviate the negative pressure in the pump chamber Pc, especially during high-speed rotation, by providing an air inlet 27 that opens at a predetermined opening time (rotation angle θ4) just before the completion of the suction stroke.

[0139] The result is, such as Figure 13 As shown, compared with existing products, it can reduce the oil pressure amplitude ΔP of the working oil, and reduce the vibration or noise associated with the oil pressure amplitude ΔP.

[0140] Moreover, it can also prevent cavitation caused by excessive negative pressure or corrosion caused by cavitation.

[0141] Furthermore, by mitigating the negative pressure during intake, the driving torque that rotates the rotating shaft 30 can be reduced. Especially at low temperatures where the working oil has high viscosity, introducing air into the working oil effectively mitigates its shear torque. As a result, the driving torque at low temperatures can be reduced.

[0142] Furthermore, when the rotating shaft 30 rotates at low speed, the suction resistance is small, the negative pressure in the pump chamber Pc is also small, and less air is introduced through the air inlet 27. On the other hand, when the rotating shaft 30 rotates at high speed, the suction resistance is large, and air is introduced without continuing to draw in working oil. Moreover, the volume change rate of the pump chamber Pc in the region before the suction stroke is about to be completed is less than 5%. Therefore, even if air is introduced, the intake volume and the ejection volume are almost the same, and the required ejection volume can be obtained.

[0143] Furthermore, the air inlet 27 is located on the wall of the housing H and is opened and closed by the end face 42 of the inner rotor 40. Therefore, compared with the case where a dedicated opening and closing valve is provided that is independent of the inner rotor 40, the structure can be simplified, the cost can be reduced, and the size can be reduced.

[0144] Furthermore, the air inlet hole 27 is provided on the flat shell cover 20 that constitutes the shell H, so only the hole-making process needs to be performed, and the hole-making process can be easily performed.

[0145] Figure 14 The outer casing 110 of the pump device M2 in the second embodiment of the present invention is indicated by the same symbols as the pump device M1 in the first embodiment, and the description is omitted.

[0146] The pump device M2 of the second embodiment includes an outer housing 110 and a housing cover 20 as the outer housing H, a rotating shaft 30 centered on a predetermined axis S, an inner rotor 40 and an outer rotor 50 as the pump unit Pu, and screws b that fasten the housing cover 20 to the outer housing 110.

[0147] The outer shell 110 is made of metal materials such as steel, cast iron, sintered steel, and aluminum alloy and is formed into a bottomed cylindrical shape, including a joint wall 11, an outer peripheral wall 12, a receiving chamber 13, an insert part 14, an intake port 15, an exhaust port 116, a bearing hole 17, three through holes 18 and a screw hole 19.

[0148] Spray nozzle 116 Figure 14 As shown, it is formed in a roughly crescent shape and includes: an offset opening region 116a, which opens offsetly to the outer periphery of the containment chamber 13; and an enlarged opening region 116b, which opens radially inwardly to the offset opening region 116a.

[0149] In addition, in the rotation direction R of the rotating shaft 30, the biased opening region 116a occupies the front half of the nozzle 116, and the enlarged opening region 116b occupies the rear half of the nozzle 116.

[0150] That is, the nozzle 116 is structured to include a biased opening region 116a, which is biasedly opened to allow the working oil pressurized by the pump chamber Pc to be ejected from the outer peripheral region of the outer rotor 50 away from the inner rotor 40 during a specified period from the start of the pressurization and ejection stroke.

[0151] Next, while referring to Figures 15 to 19 The operation of the pump unit M2 will be explained. Furthermore, the sequential operation of the rotating shaft 30 and the inner rotor 40 when rotating counterclockwise (in the direction of arrow R) will be shown. Here, the explanation will focus on the pump chamber Pc defined behind a protrusion 44 (marked with a black dot) of the inner rotor 40 in the direction of rotation R.

[0152] First, such as Figure 15 As shown, when the inner rotor 40 is at a rotation angle θ0, the suction stroke (at the beginning of the suction stroke) begins, inhaling working oil from the suction port 15.

[0153] Next, when the inner rotor 40 rotates to the position of rotation angle θ1 (approximately 90 degrees here), it is in the middle of the process of drawing working oil from the suction port 15 into the pump chamber Pc (suction stroke).

[0154] Next, when the inner rotor 40 rotates to a position with a rotation angle θ2 (approximately 150 degrees in this case), it is in the middle of the process of further drawing working oil from the suction port 15 into the pump chamber Pc (suction stroke). Moreover, in this state, although the pump chamber Pc is close to the air inlet hole 27, the end face 42 of the inner rotor 40 blocks the air inlet hole 27.

[0155] Next, as Figure 16 As shown, when the inner rotor 40 rotates to a position with a rotation angle θ3 (approximately 165 degrees in this case), it is in the following state: although it is in the suction stroke where working oil is further drawn from the suction port 15 into the pump chamber Pc, the suction port 15 is compressed and gradually becomes smaller. Moreover, in this state, although the pump chamber Pc is adjacent to the air inlet port 27, the end face 42 of the inner rotor 40 blocks the air inlet port 27.

[0156] Next, when the inner rotor 40 rotates to the position of rotation angle θ4 (approximately 172 degrees in this case), it is just before the suction stroke of drawing working oil from the suction port 15 into the pump chamber Pc is completed, and the suction port 15 is compressed, increasing the passage resistance. Therefore, when the rotating shaft 30 rotates at a particularly high speed, the working oil does not continue to flow into the pump chamber Pc, and the gas environment inside the pump chamber Pc is in a state of high negative pressure.

[0157] Just before the suction stroke is completed, the end face 42 of the inner rotor 40 leaves the air inlet hole 27, opening the air inlet hole 27. Therefore, due to the negative pressure of the pump chamber Pc, outside air begins to be drawn into the pump chamber Pc through the air inlet hole 27.

[0158] Furthermore, when the inner rotor 40 rotates to the position of rotation angle θ5 (approximately 185 degrees in this case), the suction stroke of drawing working oil from the suction port 15 into the pump chamber Pc is approaching completion. The air inlet 27 remains open, and due to the negative pressure in the pump chamber Pc, external air continues to flow into the pump chamber Pc under the action of inertial force. As a result, the negative pressure in the pump chamber Pc decreases.

[0159] Furthermore, such as Figure 17 As shown, when the inner rotor 40 rotates to the position of rotation angle θ6 (approximately 192 degrees in this case), the suction port 15 closes and the suction stroke is completed. That is, the completion of the suction stroke is the point in time when the suction port 15 is closed.

[0160] At this time, the pump chamber Pc is not connected to the nozzle 116 and is in a closed, isolated area. On the other hand, the air inlet 27 remains open, and the outside air is also flowing into the pump chamber Pc under the action of inertial force. Up to this point, the negative pressure in the pump chamber Pc has been sufficiently reduced.

[0161] Thus, before the pressurization and ejection strokes begin after the suction stroke is completed, the negative pressure in the pump chamber Pc is eased by the introduced external air.

[0162] Next, when the inner rotor 40 rotates to the position of rotation angle θ7 (approximately 205 degrees in this case), the air inlet 27 is blocked by the end face 42 of the inner rotor 40. Moreover, the pump chamber Pc begins to communicate with the biased opening region 116a of the nozzle 116 through a narrow area, and the working oil in the pump chamber Pc begins to be ejected into the nozzle 116 (at the beginning of the pressurization and ejection stroke).

[0163] At the start of the pressurization and ejection stroke, the negative pressure in the pump chamber Pc has been eased, thus suppressing or preventing the backflow of the working oil in the pump chamber Pc from the previous stroke. Moreover, since the backflow is suppressed or prevented, the pressure rise caused by the subsequent flow is also suppressed or prevented.

[0164] Next, when the inner rotor 40 rotates to the position of rotation angle θ8, the working oil in the pump chamber Pc is pressurized and ejected from the biased opening region 116a of the nozzle 116 to the downstream side of the nozzle 116. That is, the working oil pressurized by the pump chamber Pc is ejected from the outer peripheral region of the outer rotor 50 away from the inner rotor 40 (pressurization and ejection stroke). At this time, the mixed air (bubbles) does not exit from the nozzle 116 due to centrifugal force, but accumulates in the region adjacent to the recess 45 of the inner rotor 40.

[0165] Next, as Figure 18 As shown, when the inner rotor 40 rotates to the position of rotation angle θ9, the working oil in the pump chamber Pc is still pressurized and sprayed from the biased opening region 116a of the nozzle 116 to the downstream side of the nozzle 116. Moreover, the mixed air (bubbles) does not spray out from the nozzle 116 due to centrifugal force, but accumulates in the region adjacent to the recess 45 of the inner rotor 40.

[0166] Next, when the inner rotor 40 passes through a rotation angle θ 9-2 Rotate to the position of rotation angle θ 9-3 When the pump chamber Pc is in position, the working oil is mainly pressurized and sprayed from the biased opening region 116a to the downstream side of the nozzle 116, while a small amount is pressurized and sprayed from the enlarged opening region 116b to the downstream side of the nozzle 116.

[0167] In this state, the mixed air (bubbles) accumulates in the region adjacent to the recess 45 of the inner rotor 40 due to centrifugal force, and is not ejected from the nozzle 116, but is flattened by pressure.

[0168] Next, as Figure 19 As shown, when the inner rotor 40 rotates to a rotation angle θ 9-4 When the pump chamber Pc is in the position, the working oil inside is pressurized and sprayed from the biased opening region 116a and the enlarged opening region 116b to the downstream side of the nozzle 116.

[0169] In this state, the mixed air (bubbles) accumulates in the region adjacent to the recess 45 of the inner rotor 40 due to centrifugal force. In this state, it is not ejected from the nozzle 116, but is flattened by pressure and dissolved into the working oil, almost disappearing.

[0170] Next, the inner rotor 40 rotates by an angle θ 10 Rotate to the position of rotation angle θ 11 The position. During this process, the working oil in the pump chamber Pc is pressurized and continuously ejected from the nozzle 116 (pressurization and ejection stroke). Moreover, at the rotation angle θ 11 Return to the position Figure 15 The position of the rotation angle θ0 shown.

[0171] Here, the description focuses on one protrusion 44, but in reality, the pump chambers Pc defined behind the four protrusions 44 each perform the same action (pumping action). Therefore, during one revolution of the rotating shaft 30, four consecutive suction strokes, pressurization strokes, and ejection strokes are performed.

[0172] In the second embodiment, the opening timing of the air inlet 27 is set to a rotation angle θ4 approximately 20 degrees before the rotation angle θ6 at which the suction stroke is completed.

[0173] That is, the opening timing of the air inlet 27 is set to just before the suction stroke is about to be completed.

[0174] Furthermore, the timing for closing the air inlet 27 is set to be when the biased opening region 116a of the nozzle 116 begins to connect with the pump chamber Pc after the suction stroke is completed.

[0175] In particular, the nozzle 116 is formed in a manner that includes an offset opening region 116a, so that the introduced air (bubbles) is not ejected during a specified period from the start of the pressurization and ejection stroke, and the working oil pressurized by the pump chamber Pc is ejected from the outer peripheral region of the outer rotor 50, which is far from the inner rotor 40. Thus, the introduced air (bubbles) can be used as a damper component to absorb and attenuate the high-pressure side of oil pressure fluctuations, thereby efficiently reducing the oil pressure amplitude.

[0176] As described above, the pump device M2 according to the second embodiment, similar to the first embodiment, can reduce the oil pressure amplitude ΔP of the working oil compared to existing products, and can also reduce vibration or noise associated with the oil pressure amplitude ΔP. Furthermore, it can prevent cavitation caused by excessive negative pressure or corrosion caused by cavitation, achieving simplification of structure, cost reduction, and miniaturization.

[0177] Furthermore, by mitigating the negative pressure during intake, the driving torque that rotates the rotating shaft 30 can be reduced. Especially at low temperatures where the working oil has high viscosity, introducing air into the working oil mitigates its shear torque. As a result, the driving torque at low temperatures can be reduced.

[0178] Figure 20 In order to apply the pump device M3 of the third embodiment of the present invention to the system of the internal combustion engine E, the same symbols are used for the same structures as in the embodiment, and the description is omitted.

[0179] The pump device M3 of the third embodiment includes an outer housing 10 and a housing cover 20 as the outer housing H, a rotating shaft 30 centered on a predetermined axis S, an inner rotor 40 and an outer rotor 50 as the pump unit Pu, a check valve 60, and screws b for fastening the housing cover 20 to the outer housing 10.

[0180] Check valve 60 is disposed, for example, downstream of air inlet 27 of housing cover 20. In addition, check valve 60 opens when the pressure in pump chamber Pc becomes negative pressure below a specified level, allowing outside air to flow into pump chamber Pc through air inlet 27 in one direction, and blocking the outflow of working oil from pump chamber Pc to the outside.

[0181] According to the pump device M3 of the third embodiment, the same effect as described in the embodiment can be obtained, and the working oil can be reliably prevented from flowing out even if the pressure in the pump chamber Pc rises.

[0182] Figures 21 to 23 The pump device M4 of the fourth embodiment of the present invention is indicated by the same symbols as those in the embodiment, and the description is omitted.

[0183] The pump device M4 of the fourth embodiment includes an outer housing 210 and a housing cover 220 as housing H, a rotating shaft 30 centered on a predetermined axis S, an inner rotor 40 and an outer rotor 50 as pump unit Pu, and screws b for fastening the housing cover 220 to the housing 210.

[0184] The outer casing 210 is formed into a bottomed cylindrical shape using metal materials such as steel, cast iron, sintered steel, and aluminum alloy, and includes a bottom wall 211, an outer peripheral wall 212, a receiving chamber 213, a bearing hole 214, an annular protrusion 215, three through holes 216, a screw hole 217, and an air inlet hole 218.

[0185] The bottom wall 211 is formed as a flat wall perpendicular to the axis S, defining the outer wall surface 211a and the inner wall surface 211b of the end face 42 and end face 52 of the pump unit Pu, which slide closely together.

[0186] The outer peripheral wall 212 protrudes cylindrically from the outer edge region of the bottom wall 211 along the axis S, defining an annular end face 212a.

[0187] The containment chamber 213 is a space defined by the bottom wall 211 and the outer peripheral wall 212, which rotatably contains the pump unit Pu.

[0188] Moreover, containment chamber 213, such as Figure 23 As shown, it includes an arc surface 213a in the form of a cylinder, the cylinder surface being centered on an axis S1 that is offset parallel to the axis S.

[0189] The arc surface 213a slides freely to support the outer peripheral surface 53 of the outer rotor 50, which is part of the pump unit Pu. Moreover, the inner edge of the arc surface 213a also functions as a fitting recess for fitting the fitting protrusion 222 of the outer casing 220.

[0190] The bearing hole 214 is formed into a cylindrical shape centered on the axis S in order to rotatably support the other end region 32 of the rotating shaft 30.

[0191] The annular protrusion 215 around the bearing hole 214 is formed into a cylindrical shape that protrudes outward in the direction of axis S in order to improve mechanical strength.

[0192] Three through holes 216 are provided for the screw B to be screwed into the screw hole 7 of the engine body 1, and are formed in such a way that they pass through from the outer wall surface 211a along the axis S to the end face 212a.

[0193] A screw hole 217 is formed on end face 212a for screwing in the screw b that attaches the outer cover 220 to the outer cover 210.

[0194] In order to introduce external air into the pump chamber Pc defined by the pump unit Pu, the air inlet 218 is formed as a circular hole that penetrates along the axis S in the wall portion of the annular protrusion 215 and the area of ​​the inner wall surface 211b where the inner rotor 40 slides.

[0195] In addition, the air inlet 218 is opened by the end face 42 of the inner rotor 40 at a predetermined opening time before the suction stroke of the pump unit Pu is about to be completed, and is closed by the end face 42 of the inner rotor 40 at a predetermined closing time after the suction stroke is completed.

[0196] Here, the air inlet 218 is located on the wall of the housing H and is opened and closed by the end face 42 of the inner rotor 40. Therefore, compared with the case where a dedicated opening and closing valve is provided that is independent of the inner rotor 40, the structure can be simplified, the cost can be reduced, and the size can be reduced.

[0197] Furthermore, the air inlet hole 218 is provided on the bottom wall 211 of the bottom cylindrical outer shell 210 that constitutes the outer shell H, so only the hole-making process needs to be performed, and the hole-making process can be easily performed.

[0198] The outer cover 220 is attached to the outer shell 210 to close the receiving chamber 213 of the outer shell 210, and is formed into a flat plate using materials such as steel, cast iron, sintered steel, and aluminum alloy.

[0199] Additionally, the outer casing 220 includes a mating wall 221, a fitting protrusion 222, an insert portion 223, an intake port 224, an exhaust port 225, a bearing hole 226, three through holes 227, and a round hole 228.

[0200] The joint wall 221 is formed as a flat wall perpendicular to the axis S, defining the outer wall surface 221a of the joint surface 3 that is joined to the engine body 1, and the inner wall surface 221b that is joined to the end face 212a of the outer shell 210.

[0201] The fitting protrusion 222, located near the center of the outer casing 220, is formed in the shape of a disk protruding from the mating wall 221 along the axis S1, defining the outer peripheral surface 222a and the inner wall surface 222b. The outer peripheral surface 222a fits into the inner edge of the arcuate surface 213a of the outer casing 210. The end faces 41 and 51 of the pump unit Pu are slidably and closely contacted with the inner wall surface 222b.

[0202] The insertion portion 223 is formed as a cylindrical shape that protrudes outward from the joint wall 221 in the direction of axis S and is centered on axis S, and is closely fitted into the fitting recess 4 of the engine body 1.

[0203] The suction port 224 has the same shape as the suction port 15 in the described embodiment, such as... Figure 22 As shown, the joint wall 221 is formed through the axis S in a generally crescent-shaped outline. In addition, with the pump device M4 engaged with the joint surface 3 of the engine body 1, the working oil guided from the outflow passage 5 is drawn into the pump chamber Pc through the suction port 224.

[0204] The nozzle 225 has the same shape as the nozzle 16 in the described embodiment, such as... Figure 22 As shown, in the area of ​​the mating wall 221 and on the side opposite to the intake port 224 and across the insertion portion 223, a generally crescent-shaped outline is formed through the axis S. Furthermore, with the pump device M4 engaged with the mating surface 3 of the engine body 1, the working oil pressurized by the pump chamber Pc is sprayed through the nozzle 225 into the inflow passage 6.

[0205] The bearing hole 226 is formed into a cylindrical shape centered on the axis S on the inner side of the insertion portion 223 in order to rotatably support one end region 31 of the rotating shaft 30.

[0206] The three through holes 227 are for the screw B to be screwed into the screw hole 7 of the engine body 1. At the position corresponding to the three through holes 216 of the outer casing 210, they are formed as circular holes that pass through along the axis S.

[0207] A circular hole 228 is formed near a through hole 227 for the screw b that attaches the outer cover 220 to the outer cover 210.

[0208] As described above, the outer casing H includes: a bottomed cylindrical outer casing 210 defining a receiving chamber 213; and a flat outer casing cover 220 defining an intake port 224, an exhaust port 225, and a connecting wall 221 that engages with an applicable object, and is connected to the outer casing 210 to close the receiving chamber 213, with an air inlet 218 provided on the outer casing 210.

[0209] In this way, the air inlet 218 is provided in the housing H in the area opposite to the side that engages with the object, so there are no obstructions on the outside of the air inlet 218, and air (outside air) can be smoothly introduced into the pump chamber Pc.

[0210] According to the pump device M4 of the fourth embodiment, similarly to the embodiments described above, the oil pressure amplitude ΔP of the working oil can be reduced compared to existing products, and the vibration or noise accompanying the oil pressure amplitude ΔP can also be reduced. Moreover, it can also prevent cavitation caused by excessive negative pressure or corrosion caused by cavitation, thereby achieving simplification of structure, reduction of cost, and miniaturization.

[0211] Furthermore, by mitigating the negative pressure during intake, the driving torque that rotates the rotating shaft 30 can be reduced. Especially at low temperatures where the working oil has high viscosity, introducing air into the working oil mitigates its shear torque. As a result, the driving torque at low temperatures can be reduced.

[0212] Furthermore, in the pump device M4 of the fourth embodiment, a nozzle with the same shape as the nozzle 116 of the second embodiment can be used, and a check valve 60 of the third embodiment can also be used.

[0213] In the described embodiment, the pump unit that provides the pumping action is represented by a pump unit Pu comprising a cycloidal rotor (inner rotor 40 and outer rotor 50) with cycloidal teeth, but is not limited to this.

[0214] For example, a rotor unit may be used that includes an inner rotor and an outer rotor with tooth profiles other than cycloidal tooth profiles. Moreover, pump units of other volume types may also be used, not limited to those including inner and outer rotors.

[0215] In the embodiment described, the inner rotor 40 and outer rotor 50 constituting the pump unit Pu are shown to have a four-lobe, five-section structure with cycloidal teeth, but this is not a limitation and structures with other numbers of segments may also be used.

[0216] In the embodiment described above, the end face 42 of the inner rotor 40 is used to open and close the air inlet hole 27 and air inlet hole 218 provided on the outer casing H. However, this is not a limitation. The location of the air inlet hole can also be changed, and the end face 52 of the outer rotor 50 can be used to open and close the air inlet hole.

[0217] The embodiment described shows a structure in which the outer casing cover 20 or outer casing body 210 constituting the outer casing H is provided with air inlet holes 27 and air inlet holes 218 by hole processing. However, a filter component for removing suspended matter in the outside air may also be provided in the middle of the passage containing the air inlet holes 27 and air inlet holes 218.

[0218] In the above embodiment, the applicable objects of the pump devices M1, M2, M3 and M4 are internal combustion engines mounted on automobiles, etc., but are not limited thereto. They can also be applied to transmissions, other lubrication machines, and fluid machines that use fluids other than working oil.

[0219] In the described embodiment, the housing H of pump devices M1, M2, M3, and M4 is shown to include a connecting wall 11 and a connecting wall 221 that engage with the applicable object. However, this is not a limitation; the housing may also be configured independently without engaging with the applicable object, suitable for systems that draw in and eject fluid via connecting pipes, etc. In this case, the air inlet is not limited to the side opposite to the connecting wall and may be located in a suitable area of ​​the housing.

[0220] As described above, the pump device of the present invention can achieve structural simplification and suppress oil pressure amplitude, and can also reduce the noise or vibration associated with the oil pressure amplitude. Therefore, it is of course applicable to internal combustion engines of automobiles or two-wheeled vehicles, as well as other lubrication machines, and is also useful in fluid machines that handle fluids other than working oil.

Claims

1. A pump device, characterized by include: The outer casing defines the inlet, outlet, and containment chamber. as well as A pump unit is disposed within the receiving chamber and a pump chamber is defined, the pump chamber expanding and contracting to provide pumping action to the fluid, including suction, pressurization, and ejection strokes. The housing includes an air inlet that opens at a predetermined time, just before the suction stroke is about to be completed, to introduce air into the pump chamber. The pump unit includes: an inner rotor that rotates about a predetermined axis; and an outer rotor that rotates in conjunction with the rotation of the inner rotor. When the rotation angle of the inner rotor over the entire range of the suction stroke is set to θ, and the rotation angle of the inner rotor from the opening moment to the completion of the suction stroke is set to Δθa, Δθa is set to the range of 0.08×θ<Δθa<0.12×θ.

2. The pump device according to claim 1, characterized in that, The air inlet is closed at a predetermined time after the intake stroke is completed.

3. The pump device according to claim 1 or 2, characterized in that, The housing includes the air inlet hole in the wall portion that slides on the end faces of the inner rotor and the outer rotor.

4. The pump device according to claim 3, characterized in that, The air inlet is positioned to open and close from the end face of the inner rotor.

5. The pump device according to claim 1 or 2, characterized in that, The nozzle includes an offset opening region that is offset from the outer peripheral region of the outer rotor, which is located away from the inner rotor, for the fluid pressurized by the pump chamber to be ejected throughout the entire specified period from the start of the pressurization and ejection stroke.

6. The pump device according to claim 1 or 2, characterized in that, The inner rotor and the outer rotor are cycloidal rotors with four blades and five segments of cycloidal teeth.

7. The pump device according to claim 2, characterized in that, When the rotation angle of the inner rotor over the entire range of the suction stroke is set as θ, the rotation angle of the inner rotor from the opening moment to the completion of the suction stroke is set as Δθa, and the rotation angle of the inner rotor from the completion of the suction stroke to the closing moment is set as Δθb, Δθb is set to the range of 0.6×Δθa<Δθb<0.7×Δθa.

8. The pump device according to claim 1 or 2, characterized in that, include: The check valve allows only the flow of air introduced into the pump chamber from the air inlet.

9. The pump device according to claim 1 or 2, characterized in that, The outer casing includes: a bottomed cylindrical outer shell defining the inlet, the outlet, a connecting wall that engages with an applicable object, and the receiving chamber; and a flat outer casing cover, which is attached to the outer casing to close the receiving chamber. The air inlet is located on the outer casing.

10. The pump device according to claim 1 or 2, characterized in that, The outer casing includes: a bottomed cylindrical outer shell defining the receiving chamber; and a flat outer casing cover defining the inlet, the outlet, and a mating wall that engages with an applicable object, and is attached to the outer casing to close the receiving chamber. The air inlet is located on the outer casing.

Images