Gear pump or gear motor

Abstract

A gear pump or a gear motor is provided with a driving gear (2), a driven gear (3), and a side plate (20), a gear (G) represents any one of the driving gear (2) and the driven gear (3), a suction passage (7a), a discharge passage (7b), a meshing region (14), and a rotation trajectory region (15) are disposed on the rotation trajectory of teeth (G1) of the gear (G), and a discharge passage (7c) is disposed on the side plate (20). A first opening (25) opposite the engagement region (14), a second opening (26) opposite the rotation trajectory region (15), and a transfer passage (27) communicating with the first opening (25) and the second opening (26) are provided.

Description

Technical Field

[0001] The present disclosure relates to a gear pump or a gear motor. Background Art

[0002] Patent document 1 discloses a gear pump or a gear motor. The gear pump or gear motor described in Patent document 1 includes gears (a driving gear and a driven gear) and a side plate arranged opposite to the driving gear and the driven gear. On the rotation trajectory of the gear, there is a meshing area where the teeth of the driving gear and the teeth of the driven gear mesh with each other.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Publication No. 2017-223122 Summary of the invention

[0006] -Technical problem to be solved by the invention-

[0007] In the meshing area, a closed area is formed, which is surrounded by the teeth of the driving gear and the teeth of the driven gear. When the gear rotates and the closed area is connected to the suction side (suction passage side), the fluid in the closed area flows into the suction side, and thus, the pressure of the fluid in the tooth groove of the gear forming the closed area may change sharply. The sharp change of fluid pressure may cause vibration or noise to increase.

[0008] An object of the present disclosure is to reduce vibration or noise.

[0009] -Technical solutions to solve technical problems-

[0010] A first aspect is directed to a gear pump or a gear motor. The gear pump or gear motor includes a driving gear 2 and a driven gear 3 meshing with each other, and a side plate 20 arranged opposite to the driving gear 2 and the driven gear 3, wherein the gear G represents any gear of the driving gear 2 and the driven gear 3, and on the rotation trajectory of the tooth G1 of the gear G, an intake passage 7a for fluid flow, an ejection passage 7b for fluid flow having a pressure higher than that of the fluid flowing in the intake passage 7a, a meshing area 14 in which the driving gear 2 and the driven gear 3 mesh, and a rotation trajectory area 15 are arranged in the order of the intake passage 7a, the rotation trajectory area 15, the ejection passage 7b and the meshing area 14 along the rotation direction of the tooth G1 of the gear G, and a first opening 25, a second opening 26 and a conveying passage 27 are provided on the side plate 20, wherein the first opening 25 is opposite to the meshing area 14, the second opening 26 is opposite to the rotation trajectory area 15, and the conveying passage 27 is connected to the first opening 25 and the second opening 26.

[0011] In the first aspect, vibration or noise can be reduced.

[0012] In the second aspect, based on the first aspect, a third opening 28 is provided on the side plate 20, the third opening 28 is opposite to the rotation trajectory area 15 and is connected to the ejection passage 7b, and the third opening 28 is located closer to the rotation direction R side of the gear G than the second opening 26.

[0013] In the second aspect, since a sudden change in the pressure of the fluid in the tooth groove G2 of the gear G can be suppressed, vibration and noise can be reduced.

[0014] In the third aspect, based on the second aspect, when any tooth groove G2 among the multiple tooth grooves G2 of the gear G is opposite to the third opening 28, in the rotation trajectory area 15, the area opposite to the second opening 26 is different from the area where the tooth groove G2 opposite to the third opening 28 is located.

[0015] In the third aspect, it is possible to suppress the second opening 26 and the third opening 28 from simultaneously facing the same tooth groove G2 and the fluid from the second opening 26 and the fluid from the third opening 28 from being simultaneously supplied to the tooth groove G2 .

[0016] In the fourth aspect, based on the second or third aspect, a closed area H surrounded by the teeth G1 of the driving gear 2 and the teeth G1 of the driven gear 3 is formed in the meshing area 14, and when the first opening 25 is opposite to the closed area H, the second opening 26 and the third opening 28 are opposite to the different tooth grooves G2 among the multiple tooth grooves G2 of the gear G.

[0017] In the fourth aspect, the process of supplying the fluid from the second opening 26 and the fluid from the third opening 28 to the tooth grooves G2 different from each other can be performed efficiently.

[0018] In the fifth aspect, based on any one of the first to fourth aspects, when any tooth groove G2 of the multiple tooth grooves G2 of the gear G is opposite to the second opening 26, the tooth groove G2 opposite to the second opening 26 and the suction passage 7a are separated by at least one tooth G1 of the multiple teeth G1 of the gear G.

[0019] In the fifth aspect, it is possible to suppress a sudden increase in the pressure of the fluid in the tooth groove G2.

[0020] In the sixth aspect, based on any one of the first to fifth aspects, the side plate 20 includes a first side plate 21 and a second side plate 22, the first side plate 21 is arranged opposite to the gear G, the second side plate 22 is fixed to the first side plate 21, and the first opening 25 and the second opening 26 are provided on the opposite surface 211 of the outer surface of the first side plate 21 opposite to the gear G, the conveying passage 27 includes a first passage portion 27a, a second passage portion 27b and a third passage portion 27c, the first passage portion 27a is provided between the first side plate 21 and the second side plate 22, the second passage portion 27b is provided on the first side plate 21, and is communicated with the first passage portion 27a and the first opening 25, and the third passage portion 27c is provided on the first side plate 21, and is communicated with the first passage portion 27a and the second opening 26.

[0021] In the sixth aspect, by providing the first passage portion 27 a between the first side plate 21 and the second side plate 22 , the passage for sending the fluid into the side plate 20 can be easily formed.

[0022] According to a seventh aspect, based on the sixth aspect, the second side plate 22 comprises a vibration-damping steel plate or a vibration-damping alloy.

[0023] In the seventh aspect, vibration of the side plate 20 can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the overall structure of a gear pump or a gear motor involved in the embodiment;

[0025] Figure 2 It is a top view of the gear;

[0026] Figure 3 is a top view showing an enclosed area;

[0027] Figure 4 is a cross-sectional view of the side panel;

[0028] Figure 5 is a top view of the first side panel;

[0029] Figure 6 is a bottom view of the first side panel;

[0030] Figure 7 is a top view of the second side panel;

[0031] Figure 8 is a bottom view of the second side panel;

[0032] Fig. 9 is a top view showing the gears of a conventional gear pump or gear motor;

[0033] Fig.10 A diagram showing the relationship between the rotation angle of a gear of a conventional gear pump or gear motor and the fluid pressure in a specific tooth groove;

[0034] Fig.11 1 is a diagram showing the relationship between the rotation angle of the gear of the gear pump or gear motor of the present embodiment and the fluid pressure in a specific tooth groove;

[0035] Fig.12 It is a top view of the gear;

[0036] Fig.13 It is a top view of the gear;

[0037] Fig.14 It is a top view of the gear. DETAILED DESCRIPTION

[0038] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the embodiments shown below, and various changes can be made without departing from the technical concept of the present disclosure. The drawings are used to conceptually illustrate the present disclosure, so for easy understanding, the size, ratio or quantity may be exaggerated or simplified as needed.

[0039] Hereinafter, exemplary embodiments are described in detail with reference to the accompanying drawings.

[0040] Reference Figure 1 , a gear pump or a gear motor 1 according to an embodiment of the present invention will be described. Figure 1 2 is a cross-sectional view of a gear pump or gear motor 1. Hereinafter, the gear pump or gear motor 1 is referred to as a gear pump 1. The gear pump 1 sucks in a fluid supplied from a storage tank storing a fluid (eg, hydraulic oil), increases its pressure, and then ejects the fluid and supplies it to a hydraulic device.

[0041] ―Overall structure―

[0042] like Figure 1 As shown, the gear pump 1 includes: a driving gear 2 and a driven gear 3 meshing with each other; a driving shaft 4 and a driven shaft 5 that respectively support the driving gear 2 and the driven gear 3 in a rotatable manner; and a housing 6 that accommodates the driving gear 2, the driven gear 3, the driving shaft 4, and the driven shaft 5. The gear pump 1 of this embodiment sucks in a fluid supplied from a storage tank storing the fluid and increases its pressure, and then ejects the fluid and supplies it to the hydraulic equipment.

[0043] Hereinafter, the direction parallel to the axis 4A of the driving shaft 4 and the axis 5A of the driven shaft 5 is sometimes referred to as the first direction A. Among the directions perpendicular to the first direction A, the direction parallel to the arrangement direction of the driving gear 2 and the driven gear 3 is sometimes referred to as the second direction B. The direction perpendicular to the first direction A and the second direction B is sometimes referred to as the third direction C (see Figure 2 ).

[0044] The housing 6 has a main body 7 and a cover 9 fixed to the main body 7 . The cover 9 is arranged on one side A1 of the housing 6 in the first direction A. An internal space 10 of the housing 6 is formed across the internal spaces of the main body 7 and the cover 9 .

[0045] In the inner space 10 of the housing 6, there are arranged a driving gear 2, a driving shaft 4 fixed or integrated with the driving gear 2, a driven gear 3, and a driven shaft 5 fixed or integrated with the driven gear 3. The shaft 4A of the driving shaft 4 and the shaft 5A of the driven shaft 5 are arranged parallel to each other.

[0046] The driving shaft 4 extends along the axis 4A of the driving shaft 4 and passes through the center of the driving gear 2. The driving shaft 4 rotates around the axis 4A together with the driving gear 2. The driven shaft 5 extends along the axis 5A of the driven shaft 5 and passes through the center of the driven gear 3. The driven shaft 5 rotates around the axis 5A together with the driven gear 3.

[0047] The driving gear 2 and the driven gear 3 mesh with each other. When the driving gear 2 rotates, the driving gear 2 transmits power to the driven gear 3 at the meshing portion of the driving gear 2 and the driven gear 3 to rotate the driven gear 3. As a result, the driving gear 2 and the driven gear 3 rotate together.

[0048] like Figure 1 and Figure 2 As shown, the driving gear 2 and the driven gear 3 are respectively configured as spur gears and are arranged in an inner space 10 formed inside the housing 6 .

[0049] The driving shaft 4 has a first driving shaft 4a located on one side A1 of the first direction A relative to the driving gear 2, and a second driving shaft 4b located on the other side A2 of the first direction A relative to the driving gear 2. The second driving shaft 4b is connected to a driving unit (e.g., a prime mover). The driven shaft 5 has a first driven shaft 5a located on one side A1 of the first direction A relative to the driven gear 3, and a second driven shaft 5b located on the other side A2 of the first direction A relative to the driving gear 2.

[0050] In the gear pump 1, the driving gear 2 and the driven gear 3 are accommodated in the internal space 10 in a state of mutual meshing, and the tooth tops thereof are in sliding contact with the inner peripheral surface of the internal space 10. Thus, the driving gear 2 and the driven gear 3 rotate while meshing in the internal space 10 of the housing 6. When rotating, the driving gear 2 and the driven gear 3 are in sliding contact with the inner peripheral surface of the internal space 10 of the housing 6, respectively, and the internal space 10 is divided into a low-pressure area and a high-pressure area.

[0051] The gear pump 1 has an active bearing 11 and a driven bearing 12, wherein the active bearing 11 supports the active shaft 4 rotatably, and the driven bearing 12 supports the driven shaft 5 rotatably. The active bearing 11 has a first active bearing 11a and a second active bearing 11b, wherein the first active bearing 11a supports the first active shaft 4a rotatably, and the second active bearing 11b supports the second active shaft 4b rotatably. The driven bearing 12 has a first driven bearing 12a and a second driven bearing 12b, wherein the first driven bearing 12a supports the first driven shaft 5a rotatably, and the second driven bearing 12b supports the second driven shaft 5b rotatably. The first active bearing 11a, the second active bearing 11b, the first driven bearing 12a, and the second driven bearing 12b each include, for example, sliding bearings.

[0052] In the internal space 10 of the housing 6, an oil seal 13 is provided between the housing 6 and the driving shaft 4. The oil seal 13 is, for example, a rubber member and is located on the other side A2 in the first direction A relative to the second driving bearing 11b.

[0053] The gear pump 1 includes a pair of side plates 20 and a pair of sealing members 30. The pair of side plates 20 are arranged in a manner of sandwiching the driving gear 2 and the driven gear 3 from both sides of the first direction A. The pair of side plates 20 are arranged opposite to the driving gear 2 and the driven gear 3, respectively. The pair of side plates 20 are arranged to be sandwiched by the driving gear 2 and the driven gear 3 and the housing 6, respectively. The driving shaft 4 and the driven shaft 5 are inserted into and pass through each of the pair of side plates 20.

[0054] One side plate 20A of the pair of side plates 20 is arranged on one side A1 of the first direction A relative to the driving gear 2 and the driven gear 3. The other side plate 20B of the pair of side plates 20 is arranged on the other side A2 of the first direction A relative to the driving gear 2 and the driven gear 3. One sealing component 30A of the pair of sealing components 30 is installed on the side plate 20A. The other sealing component 30B of the pair of sealing components 30 is installed on the side plate 20B.

[0055] like Figure 2As shown, in the gear pump 1, a suction passage 7a communicating with the low-pressure area of ​​the internal space 10 and a discharge passage 7b communicating with the high-pressure area of ​​the internal space 10 are formed on the housing 6. The suction passage 7a and the discharge passage 7b are arranged with a gap between them along the third direction C. The pressure of the fluid flowing in the discharge passage 7b is greater than the pressure of the fluid flowing in the suction passage 7a.

[0056] Hereinafter, any gear of the driving gear 2 and the driven gear 3 may be referred to as a gear G. The shaft of the gear G may be referred to as a shaft GA. The shaft GA indicates any shaft of the shaft 4A of the driving shaft 4 and the shaft 5A of the driven shaft 5 .

[0057] The gear G includes a plurality of teeth G1. The plurality of teeth G1 are arranged along a rotation direction R of the gear G. The plurality of teeth G1 rotate around an axis GA. A gap, ie, a tooth groove G2, is formed between adjacent teeth G1.

[0058] On the rotation locus of the tooth G1 of the gear G, there are the suction passage 7 a , the discharge passage 7 b , the meshing region 14 , and the rotation locus region 15 .

[0059] The meshing area 14 represents the area where the driving gear 2 and the driven gear 3 mesh with each other. In the meshing area 14, the driving gear 2 and the driven gear 3 mesh with each other, thereby forming a closed area H surrounded by the teeth G1 of the driving gear 2 and the teeth G1 of the driven gear 3 (refer to Figure 3 ).

[0060] like Figure 2 As shown, the rotation track region 15 is a region located between the suction passage 7a and the discharge passage 7b in the track of the tooth G1 formed when the gear G rotates. In the rotation track region 15, when the gear G rotates, a process for increasing the pressure of the fluid in the tooth groove G2 is performed.

[0061] The suction passage 7a, the discharge passage 7b, the meshing area 14, and the rotation track area 15 are arranged in the order of the suction passage 7a, the rotation track area 15, the discharge passage 7b, and the meshing area 14 along the rotation direction of the tooth G1 of the gear G. The rotation direction R indicates the direction in which the gear G (the tooth G1 of the gear G) rotates when the gear pump 1 is working. The operation of the gear pump 1 indicates that the gear G is rotated to transport the fluid to the hydraulic equipment via the discharge passage 7b, the rotation track area 15, and the discharge passage 7b.

[0062] When the tooth G1 of the gear G rotates in the rotation track area 15, the front end G3 of the gear G comes into sliding contact with the wall surface 10a of the internal space 10. As a result, the tooth groove G2 is sealed.

[0063] In the gear pump 1, a pipe from a storage tank storing a fluid is connected to the suction passage 7a of the housing 6. A pipe leading to a hydraulic device is connected to the discharge passage 7b. When the driving shaft 4 of the driving gear 2 is rotated by a driving unit (for example, a prime mover) not shown in the figure, the driven gear 3 meshing with the driving gear 2 rotates along the rotation direction R together with the driving gear 2. As a result, the fluid in the space surrounded by the inner circumferential surface of the internal space 10 and the tooth groove G2 is sent to the discharge passage 7b side along the rotation direction R under the rotation of the gear G, as a result, the discharge passage 7b side becomes the high-pressure side and the suction passage 7a side becomes the low-pressure side with the meshing area 14 as the boundary.

[0064] When the fluid is sent to the discharge passage 7b side and the suction passage 7a side becomes negative pressure, the fluid in the storage tank is sucked into the internal space 10 on the low pressure side through the pipe and the suction passage 7a. The fluid in the space surrounded by the inner circumferential surface of the internal space 10 and the tooth groove G2 is transported from the suction passage 7a along the rotation direction R under the rotation of the gear G, and is pressurized to a high pressure when passing through the rotation track area 15, and then supplied to the discharge passage 7b. The fluid supplied to the discharge passage 7b is supplied to the hydraulic equipment through the pipe.

[0065] - Side panels -

[0066] like Figure 1 and Figures 4 to 8 As shown, the side plate 20 has an approximately figure-8 shape. The side plate 20 includes a first side plate 21 and a second side plate 22. The side plate 20 has a shape in which the first side plate 21 and the second side plate 22 overlap each other.

[0067] The first side plate 21 includes a pair of arc portions 21a and a central portion 21b. The pair of arc portions 21a are each formed in an arc shape. The central portion 21b is located between the pair of arc portions 21a and is continuously formed between the pair of arc portions 21a.

[0068] The outer surface of the first side plate 21 includes an opposing surface 211 and a first mating surface 212 . The opposing surface 211 is opposed to the gear G. The first mating surface 212 is a surface located on the back side of the opposing surface 211 .

[0069] The outer surface of the second side plate 22 includes a second mating surface 221 and a back surface 222. The second mating surface 221 is opposite to the first mating surface 212 of the first side plate 21 and overlaps with the first mating surface 212. The back surface 222 is located on the back side of the second mating surface 221.

[0070] The first side plate 21 and the second side plate 22 constitute a set of side plates 20. The side plate 20 is configured such that the back surface 222 is located on the back side of the facing surface 211.

[0071] A pair of through holes 24 are provided on the side plate 20 and penetrate the side plate 20 along the first direction A. The pair of through holes 24 are arranged with a spacing from each other along the second direction B. The pair of through holes 24 are respectively connected to the pair of arc portions 21a (refer to Figure 5 ) correspondingly. A pair of through holes 24 are respectively arranged at the corresponding arc portions 21a. As for the pair of through holes 24, the driving shaft 4 is inserted into and passes through one of the through holes, and the driven shaft 5 is inserted into and passes through the other through hole.

[0072] The back surface 222 of the side plate 20 is provided with a seal groove 222a to which the seal member 30 is mounted. The seal member 30 is, for example, a rubber member. The seal groove 222a has a shape in which the back surface 222 is recessed.

[0073] A first opening 25 , a second opening 26 and a third opening 28 are provided on the opposite surface 211 of the first side plate 21 .

[0074] The first opening 25 is provided at a position opposite to the meshing area 14 . The second opening 26 is provided at a position opposite to the rotation track area 15 .

[0075] The conveying path 27 communicates with the first opening 25 and the second opening 26. The conveying path 27 includes a first path portion 27a, a second path portion 27b, and a third path portion 27c.

[0076] The first passage portion 27a is a space provided between the first side plate 21 and the second side plate 22. In the present embodiment, a groove is formed on the first mating surface 212 of the first side plate 21, the second mating surface 221 of the second side plate 22 is formed into a plane, and the first passage portion 27a is formed by the space between the groove of the first mating surface 212 and the second mating surface 221. It should be noted that a groove may also be formed on the second mating surface 221 of the second side plate 22, the first mating surface 212 of the first side plate 21 is formed into a plane, and the first passage portion 27a is formed by the space between the groove of the second mating surface 221 and the first side plate 21. It is also possible to form grooves on the first mating surface 212 and the second mating surface 221, respectively, and form the first passage portion 27a by the space surrounded by the groove of the first mating surface 212 and the groove of the second mating surface 221.

[0077] The second passage portion 27b is a hole that penetrates the first side plate 21 in the first direction A. The second passage portion 27b communicates with the first opening 25 and the first passage portion 27a.

[0078] The third passage portion 27c is a hole that penetrates the first side plate 21 in the first direction A. The third passage portion 27c communicates with the second opening 26 and the first passage portion 27a.

[0079] Two first openings 25 are provided on the central portion 21b. Second openings 26 are provided on the pair of arc portions 21a, respectively. The two first openings 25 correspond to the pair of second openings 26, respectively. The conveying passage 27 extends from each of the two first openings 25 toward the corresponding second opening 26. A pair of a series of groove structures consisting of the first openings 25, the second openings 26 and the conveying passage 27 is provided.

[0080] The third opening 28 is provided at a position opposite to the rotation track area 15. The third opening 28 is connected to the ejection passage 7b. The third opening 28 has a shape extending in an arc shape from the ejection passage 7b along the outer periphery of the first side plate 21 to the suction passage 7a side opposite to the rotation track area 15. The third opening 28 is located at a position closer to the rotation direction R side of the gear G than the second opening 26. The third opening 28 is provided on each of the pair of arc portions 21a.

[0081] like Figure 5 As shown, the opposite surface 211 includes: Figure 2 ) and the first opposing surface 211a opposite to the meshing area 14 (refer to Figure 2 ) is provided with a second relative surface 211b, a suction side release groove 7a1 and an ejection side release groove 7b1. A first relative surface 211 is provided on a pair of arc portions 21a, respectively. The second relative surface 211b is provided at the central portion 21b. The suction side release groove 7a1 is provided downstream of the second relative surface 211b in the rotation direction R, and constitutes a part of the suction passage 7a. The ejection side release groove 7b1 is provided upstream of the second relative surface 211b in the rotation direction R, and constitutes a part of the ejection passage 7b. The suction side release groove 7a1 and the ejection side release groove 7b1 have a shape that is recessed relative to the first relative surface 211a and the second relative surface 211b.

[0082] ―Pressure changes of fluid in tooth grooves―

[0083] like Figure 2 As shown in the figure, when the gear G rotates in the rotation direction R, when the tooth groove G2 passes above the suction passage 7a, the fluid in the tooth groove G2 becomes a low pressure state because it is connected to the suction passage 7a. When the tooth groove G2 further rotates and faces the second opening 26, the fluid in the closed area H (refer to Figure 3) is delivered to the tooth groove G2 through the first opening 25 and the delivery passage 27, thereby increasing the pressure of the fluid in the tooth groove G2. When the tooth groove G2 further rotates and faces the third opening 28, the high-pressure fluid in the ejection passage 7b is supplied to the tooth groove G2 through the third opening 28. When the high-pressure fluid from the third opening 28 is supplied to the tooth groove G2, the pressure of the fluid in the tooth groove G2 further increases, thereby becoming a high-pressure state. The tooth groove G2 after passing through the third opening 28 rotates toward the ejection passage 7b with the high-pressure fluid contained in the tooth groove G2.

[0084] Since the gear G rotates with the high-pressure fluid stored in the tooth groove G2, the high-pressure fluid stored in the tooth groove G2 applies pressure to the side plate 20 in a direction away from the gear G. As a result, the side plate 20 can be prevented from contacting the gear G and being worn.

[0085] -test-

[0086] The inventors of the present application conducted a test for comparing the performance of the gear pump 1 according to the present embodiment with the performance of the conventional gear pump 100 .

[0087] - Test results of existing gear pumps -

[0088] like Fig. 9 As shown, the conventional gear pump (gear pump or gear motor) 100 does not have the first opening 25, the second opening 26, and the delivery passage 27, which is different from the gear pump 1 of this embodiment. In the conventional gear pump, the specific tooth groove 101 among the plurality of tooth grooves will be described.

[0089] Fig.10 The relationship between the rotation angle of the gear 102 (any gear of the driving gear and the driven gear) of the conventional gear pump 100 and the fluid pressure in the specific tooth groove 101 is shown. The specific tooth groove 101 indicates any tooth groove 101 among the plurality of tooth grooves 101 of the gear 102.

[0090] like Fig. 9 and Fig.10 As shown, in the conventional gear pump 100, when the specific tooth groove 101 is located between the suction passage 103 and the opening 104, the fluid in the specific tooth groove 101 becomes low pressure (refer to Fig.10 When the specific tooth groove 101 faces the opening 104, the high-pressure fluid in the ejection passage 105 is supplied to the specific tooth groove 101 through the opening 104, so that the pressure of the fluid in the specific tooth groove 101 rises sharply (refer to Fig.10 From the time when the specific tooth groove 101 is opposite to the opening 104 until the specific tooth groove 101 reaches the meshing area 106, the fluid in the specific tooth groove 101 is in a high pressure state (see arrow V2). Fig.10 When the specific tooth groove 101 reaches the meshing area 106 and forms a closed area 107 in the specific tooth groove 101, the fluid in the specific tooth groove 101 is compressed in the closed area 107, so that the pressure of the fluid in the specific tooth groove 101 further increases (refer to Fig.10 When the pressure of the fluid in the specific tooth groove 101 further increases, if the closed area 107 formed by the specific tooth groove 101 is connected to the suction passage 103 through the meshing area 106, the high-pressure fluid in the specific tooth groove 101 is rapidly transported to the suction side (suction passage 103 side) due to the pressure difference between the fluid in the suction passage 103 and the closed area 107 formed by the specific tooth groove 101, and the pressure of the fluid in the specific tooth groove 101 is rapidly reduced (refer to Fig.10 The sudden change of fluid pressure in the tooth groove 101 may cause vibration or noise to increase. At the moment when the closed area 107 is connected to the suction side, the high-pressure fluid compressed in the closed area 107 flows into the suction side to generate cavitation, and as a result, the components of the gear pump 100 may be damaged.

[0091] - Test results of the gear pump according to the present embodiment -

[0092] Fig.11 The relationship between the rotation angle of the gear G of the gear pump 1 of the present embodiment and the pressure of the fluid in the specific tooth groove G2 is shown. The specific tooth groove G2 indicates an arbitrary tooth groove G2 among the plurality of tooth grooves G2 of the gear G.

[0093] like Figure 2 and Fig.11 As shown, in the gear pump 1 of this embodiment, when the specific tooth groove G2 is located between the suction passage 7a and the second opening 26, the fluid in the tooth groove 101 becomes low pressure (refer to Fig.11 When the specific tooth groove G2 is opposite to the second opening 26, the first opening 25 and the conveying path 27 (see arrow W1) are connected. Figure 5 ), the second opening 26 closes the fluid in the area H (refer to Figure 3 ) is supplied to a specific tooth groove G2, thereby increasing the pressure of the fluid in the specific tooth groove G2 (refer to Fig.11 When the specific tooth groove G2 further rotates and faces the third opening 28, the high-pressure fluid in the ejection passage 7b is supplied to the specific tooth groove G2 through the third opening 28, so that the pressure of the fluid in the specific tooth groove G2 further increases (refer to Fig.11 In the gear pump 1 of the present embodiment, the fluid from the second opening 26 and the fluid from the third opening 28 are delivered to the specific tooth groove G2 in stages, as shown in FIG. Fig.11As shown by the arrow W2 , a sudden increase in the pressure of the fluid in the specific tooth groove G2 is suppressed, and the pressure of the fluid increases gradually or in stages.

[0094] In the gear pump 1 of this embodiment, from the time when the specific tooth groove G2 faces the third opening 28 until the specific tooth groove G2 reaches the meshing area 14, the fluid in the specific tooth groove G2 becomes a high pressure state (see Fig.11 The specific tooth groove G2 reaches the meshing area 14, thereby forming a closed area H in the specific tooth groove G2 (refer to Figure 3 ), the fluid in the closed area H passes through the first opening 25 and the delivery passage 27 (refer to Figure 5 ) and the second opening 26 to the other tooth grooves G2. As a result, when the closed area H passes through the meshing area 14, the pressure of the fluid in the specific tooth groove G2 forming the closed area H decreases (refer to Fig.11 When the closed area H formed by the specific tooth groove G2 is connected to the suction side (suction passage H side) through the meshing area 14, the fluid in the specific tooth groove G2 is sent to the suction side due to the pressure difference with the fluid in the suction passage 7a, so that the pressure of the fluid in the specific tooth groove G2 is further reduced (refer to Fig.11 In the gear pump 1 of this embodiment, when the closed area H passes through the meshing area 106, the fluid in the specific tooth groove G2 forming the closed area H is sent from the first opening 25 to the other tooth grooves G2, so the pressure of the fluid in the specific tooth groove G2 becomes reduced. As a result, Fig.11 As shown by the arrow W4, even if the closed area H formed by the specific tooth groove G2 is connected to the suction side through the meshing area 106, the sudden drop in the pressure of the fluid in the specific tooth groove G2 is suppressed, so that the pressure of the fluid is gradually or staged.

[0095] As described above, the gear pump 1 of the present embodiment can suppress the rapid change in the pressure of the fluid in the tooth groove G2 compared to the existing gear pump 100. As a result, it is possible to reduce the vibration or noise generated in the gear pump 1. Since it is possible to suppress the high-pressure fluid from flowing into the suction side from the tooth groove G2 (closed area H) just after passing through the meshing area 106, it is possible to suppress the parts of the gear pump 1 from being damaged by cavitation.

[0096] -Effect-

[0097] As described above, the side plate 20 is provided with a first opening 25 opposite to the meshing area 14, a second opening 26 opposite to the rotation track area 15, and a delivery passage 27 connected to the first opening 25 and the second opening 26. Thus, by delivering the fluid that becomes high pressure in the closed area H from the first opening 25 to the rotation track area 15 via the delivery passage 27 and the second opening 26, the pressure of the fluid in the closed area H can be reduced before the closed area H passes through the meshing area 14. Thus, after the closed area H passes through the meshing area 14, even if the fluid in the closed area H is supplied to the suction side release groove 7a1, the rapid change in the pressure of the fluid in the tooth groove G2 can be suppressed. As a result, the vibration or noise generated in the gear pump 1 can be reduced. It is also possible to suppress damage to the components of the gear pump 1 due to cavitation.

[0098] The third opening 28 is located closer to the rotation direction R side of the gear G than the second opening 26. Thus, after the fluid in the closed area H is supplied to the tooth groove G2 through the second opening 26, the fluid in the ejection passage 7b is supplied to the tooth groove G2 through the third opening 28, thereby making it possible to gradually or stage-by-stage increase the pressure of the fluid in the tooth groove G2. As a result, it is possible to suppress a sudden change in the pressure of the fluid in the tooth groove G2, thereby reducing vibration or noise generated in the gear pump or gear motor.

[0099] If the rotation speed of the gear G increases, the fluid in the closed area 107 may generate abnormally high pressure, and the abnormally high pressure can be reduced by setting the opening area of ​​the first opening 25 and the volume of the conveying passage 27 according to the magnitude of the abnormally high pressure. The fluid in the closed area H is conveyed to the tooth groove G2 in the rotating track area 15 by the conveying passage 27, so that the fluid can be supplied to the tooth groove G2 in the rotating track area 15, thereby improving the conveying efficiency of the fluid to the tooth groove G2 in the rotating track area 15.

[0100] The above describes the embodiments and variations, but it should be understood that various changes can be made to the methods and specific circumstances without departing from the spirit and scope of the claims (for example, the following (1) to (5)). As long as the functions of the objects of the present disclosure are not affected, the embodiments, variations, and other embodiments can also be appropriately combined or replaced.

[0101] (1) It is preferred that when any of the plurality of tooth grooves G2 is opposite to the third opening 28, in the rotation track area 15, the area opposite to the second opening 26 is different from the area where the tooth groove G2 opposite to the third opening 28 is located. In other words, it is preferred that the second opening 26 and the third opening 28 are as follows: Fig.12 As shown in FIG. 1 , it is not preferred that the tooth groove G2 is not aligned with the same tooth groove G2 at the same time. Fig.13By adopting such a structure, the following situations can be suppressed: Fig.13 As shown, the second opening 26 and the third opening 28 are opposite to the same tooth slot G2 at the same time, and the fluid from the second opening 26 and the fluid from the third opening 28 are simultaneously supplied to the tooth slot G2, resulting in a sharp change in the pressure of the fluid in the tooth slot G2.

[0102] (2) Fig.12 As shown, preferably, the second opening 26 and the third opening 28 are opposite to different tooth grooves G2 when the first opening 25 is opposite to the closed area H. By adopting such a structure, the process of supplying the fluid from the second opening 26 and the fluid from the third opening 28 to different tooth grooves G2 can be effectively performed.

[0103] (3) Fig.14 , a structure is shown in which the tooth groove G2 and the suction passage 7a opposite to the second opening 26 are not separated by the teeth G1 but are connected to each other when the second opening 26 is opposite to any tooth groove G2 among the plurality of tooth grooves G2. In the case of adopting this structure, even if the fluid in the closed area H is supplied to the tooth groove G2 from the second opening 26, the fluid will be sent to the suction passage 7a, so that the pressure of the fluid in the tooth groove G2 will not rise, but will become the same as the pressure of the fluid in the suction passage 7a (low pressure state). In this case, when the tooth groove G2 further rotates and faces the third opening 28, so that the high-pressure fluid is supplied to the tooth groove G2 from the third opening 28, there is a possibility that the pressure of the fluid in the tooth groove G2 will rise sharply from low pressure to high pressure.

[0104] In order to prevent the above problems from happening, Fig.12 As shown, preferably, when the second opening 26 is opposite to any tooth groove G2 among the plurality of tooth grooves G2, the tooth groove G2 opposite to the second opening 26 and the suction passage 7a are separated by at least one tooth G1 and are not connected to each other. Under this structure, when the fluid in the closed area H is supplied to the tooth groove G2 from the second opening 26, the tooth G1 inhibits the fluid from being sent to the suction passage 7a, and the fluid becomes contained in the tooth groove G2. Thus, it is possible to maintain a state in which the fluid pressure in the tooth groove G2 is higher than the fluid pressure in the suction passage 7a (first rise). From this state, the tooth groove G2 further rotates, and a high-pressure fluid is supplied to the tooth groove G2 from the third opening 28, thereby enabling the fluid pressure in the tooth groove G2 to further rise (second rise). Therefore, by effectively performing the process of gradually or stage-by-stage rise of the fluid pressure in the tooth groove G2 using the first rise and the second rise, it is possible to inhibit the fluid pressure in the tooth groove G2 from rising sharply.

[0105] (4) Figure 1 and Figure 4 As shown, the first side plate 21 may include a copper alloy. Therefore, when the gear G rotates, the sliding property of the gear G relative to the first side plate 21 can be improved. The second side plate 22 may include a vibration-damping steel plate or a vibration-damping alloy. Thus, the vibration of the side plate 20 can be effectively reduced.

[0106] (5) Figure 1 and Figure 4 As shown, in this embodiment, the side plate 20 is composed of two plates (a first side plate 21 and a second side plate 22), but the present invention is not limited thereto. The side plate 20 may be composed of one plate, or may be composed of three or more plates.

[0107] (6) Figure 2 As shown, the third opening 28 of the present embodiment has a shape extending in an arc shape from the ejection passage 7b along the outer periphery of the side plate 20 to the suction passage 7a side, and is thus connected to the ejection passage 7b. However, the present invention is not limited thereto, and the shape of the third opening 28 is not particularly limited. The third opening 28, for example, may not be connected to the ejection passage 7b, but may be an opening located at a position away from the ejection passage 7b relative to the rotation trajectory area 15. In this case, the passage is formed by a hole provided in the side plate 20 and / or a groove formed on the arc-shaped side portion of the side plate 20. Furthermore, the passage is connected to the third opening 28 and the ejection passage 7b, whereby the third opening 28 and the ejection passage 7b are connected via the passage.

[0108] - Industrial Applicability -

[0109] As mentioned above, the present disclosure is useful with a gear pump or a gear motor.

[0110] - Explanation of symbols -

[0111] 1 Gear pump or gear motor

[0112] 2 Driving gear

[0113] 3 Driven gear

[0114] 7a Inhalation pathway

[0115] 7b Exhaust channel

[0116] 14 Meshing area

[0117] 15 Rotation track area

[0118] 20 Side Panel

[0119] 25 First Opening

[0120] 26 Second Opening

[0121] 27 Conveyor Path

[0122] G Gear

[0123] G1 teeth

Claims

1. A gear pump or a gear motor, characterized in that: The gear pump or gear motor comprises: a driving gear (2) and a driven gear (3) meshing with each other; and a side plate (20) arranged opposite to the driving gear (2) and the driven gear (3). The gear (G) represents any gear among the driving gear (2) and the driven gear (3). On the rotation track of the teeth (G1) of the gear (G), an intake passage (7a) for fluid flow, an ejection passage (7b) for fluid flow having a pressure higher than that of the fluid flowing in the intake passage (7a), a meshing area (14) where the driving gear (2) and the driven gear (3) mesh, and a rotation track area (15) are arranged in the order of the intake passage (7a), the rotation track area (15), the ejection passage (7b), and the meshing area (14) along the rotation direction of the teeth (G1) of the gear (G), The side plate (20) is provided with a first opening (25), a second opening (26) and a conveying passage (27). The first opening (25) is opposite to the engagement area (14), The second opening (26) is opposite to the rotation track area (15), The conveying passage (27) communicates with the first opening (25) and the second opening (26).

2. The gear pump or gear motor according to claim 1, characterized in that: The side plate (20) is provided with a third opening (28), the third opening (28) is opposite to the rotation track area (15) and is connected to the ejection passage (7b). The third opening (28) is located closer to the rotation direction (R) side of the gear (G) than the second opening (26).

3. The gear pump or gear motor according to claim 2, characterized in that: When any tooth groove (G2) among the multiple tooth grooves (G2) of the gear (G) is opposite to the third opening (28), in the rotation trajectory area (15), the area opposite to the second opening (26) and the area where the tooth groove (G2) opposite to the third opening (28) are located are different.

4. The gear pump or gear motor according to claim 2 or 3, characterized in that: In the meshing area (14), a closed area (H) is formed which is surrounded by the teeth (G1) of the driving gear (2) and the teeth (G1) of the driven gear (3). In a state where the first opening (25) faces the closed area (H), the second opening (26) and the third opening (28) face different tooth grooves (G2) among the plurality of tooth grooves (G2) of the gear (G).

5. The gear pump or gear motor according to any one of claims 1 to 4, characterized in that: When any tooth groove (G2) among the plurality of tooth grooves (G2) of the gear (G) is opposite to the second opening (26), the tooth groove (G2) opposite to the second opening (26) and the suction passage (7a) are separated by at least one tooth (G1) among the plurality of teeth (G1) of the gear (G).

6. The gear pump or gear motor according to any one of claims 1 to 5, characterized in that: The side plate (20) comprises a first side plate (21) and a second side plate (22), The first side plate (21) is arranged opposite to the gear (G). The second side plate (22) is fixed to the first side plate (21), The first opening (25) and the second opening (26) are provided on the opposite surface (211) of the outer surface of the first side plate (21) and opposite to the gear (G). The conveying passage (27) includes a first passage portion (27a), a second passage portion (27b) and a third passage portion (27c). The first passage portion (27a) is disposed between the first side plate (21) and the second side plate (22). The second passage portion (27b) is disposed on the first side plate (21) and is communicated with the first passage portion (27a) and the first opening (25). The third passage portion (27c) is provided on the first side plate (21) and is communicated with the first passage portion (27a) and the second opening (26).

7. The gear pump or gear motor according to claim 6, characterized in that: The second side plate (22) comprises a vibration-damping steel plate or a vibration-damping alloy.

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