Turbopump and fluid supply unit

Abstract

A kind of turbine pump, in order to improve the fluid pressurization delivery performance when supply surplus operation of the consumption flow in downstream side is less than the fluid pressurization supply ability of impeller, fluid is pressurized and delivered to the downstream of suction passage (32) by the rotation of impeller (34) arranged in suction passage (32).The part of suction passage (32) located in the upstream side of impeller (34) is provided with throttle hole (36a), throttle hole (36a) reduces the inner diameter in the state of forming reverse surface (40) towards downstream side, and reverse partition portion (42) for limiting fluid circumferential flow is arranged on reverse surface (40).

Description

Technical Field

[0001] The present invention relates to a turbopump and a fluid supply unit having a turbopump, the turbopump delivering fluid downstream of the fluid passage via an impeller disposed in the fluid passage. Background Technology

[0002] Turbopumps equipped with impellers pose the risk that when the downstream flow rate is less than the fluid pressurization capacity, a swirling backflow can occur in the fluid at the impeller inlet, leading to various problems. More specifically, even with a fixed turbine pump speed, the aforementioned backflow can occur if the opening of the fluid discharge nozzle connected to the downstream side is narrowed, or if the discharge capacity of the variable capacity pump connected to the downstream side is set to a smaller value. Furthermore, even with a fixed downstream flow rate, the aforementioned backflow can occur if the turbine pump speed on the upstream side increases (hereinafter, these operating conditions are collectively referred to as oversupply operation). Therefore, inventions have been provided that provide an orifice ring with a reverse-flowing surface on the upstream side of the impeller to allow the backflowing fluid to collide with it, and provide a rectifier unit between the orifice ring and the impeller to suppress fluid swirling (see, for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2010-14077 Summary of the Invention

[0004] However, the fluid passing through the rectifier unit diffuses circumferentially upon contact with the reversing surface of the perforated ring. Therefore, due to the perforated ring, it is sometimes impossible to efficiently reverse the fluid flow, and there is still room for improvement considering the pressurization and delivery performance of the fluid during overload operation. Furthermore, the above problems are not necessarily limited to devices with inducers; they can occur in any device that pressurizes and delivers fluid downstream through impeller rotation.

[0005] The present invention was made in view of the above-mentioned problems, and its object is to provide a turbopump and fluid supply unit that can improve the pressurization and delivery performance of fluids when supplying excess operation.

[0006] To achieve the above objectives, the turbopump of the present invention pressurizes and delivers fluid to the downstream of the fluid passage by rotating an impeller provided in the fluid passage. The portion of the fluid passage located on the upstream side of the impeller is provided with a reduced diameter section. The reduced diameter section reduces its inner diameter by forming a reverse surface facing the downstream side. The reverse surface is provided with a reverse partition section for restricting the circumferential flow of fluid.

[0007] According to the present invention, since a reversing partition is provided on the reversing surface, the fluid does not diffuse circumferentially when it comes into contact with the reversing surface, but is guided to the center side of the fluid passage. As a result, it can be efficiently reversed even when a counterflow occurs, and the fluid pressurization and delivery performance can be improved even when the flow rate consumed on the downstream side is less than the impeller's fluid pressurization supply capacity during oversupply operation. Attached Figure Description

[0008] Figure 1 This is a cross-sectional side view of a fluid supply unit comprising a turbine pump as described in Embodiment 1 of the present invention.

[0009] Figure 2 It means Figure 1 A cross-sectional perspective view of the main part of the fluid supply unit shown.

[0010] Figure 3A It means applicable Figure 1 The image shows a perspective view of the impeller of the turbine pump in the fluid supply unit.

[0011] Figure 3B yes Figure 1 DD line cross-section diagram.

[0012] Figure 4 Viewed from the reverse side opposite the impeller. Figure 1 A perspective view of the orifice plate used to form the reduced diameter section in the turbine pump of the fluid supply unit shown.

[0013] Figure 5A It means Figure 4 The diagram of the orifice plate shown is viewed from the reverse side opposite the impeller.

[0014] Figure 5B yes Figure 5A EE line cross-section diagram.

[0015] Figure 6 This is a perspective view of a deformed example of the orifice plate, viewed from the reverse side opposite the impeller.

[0016] Figure 7A It means Figure 6 The diagram showing a modified example of the orifice plate is viewed from the reverse side opposite the impeller.

[0017] Figure 7B yes Figure 7A The FF line cross-section diagram.

[0018] Figure 8 This is a cross-sectional side view of a fluid supply unit comprising a turbine pump as described in Embodiment 2 of the present invention.

[0019] Figure 9 It means Figure 8 An enlarged cross-sectional view of the main part of the fluid supply unit shown.

[0020] Figure 10 It means Figure 8 A cross-sectional perspective view of the main part of the fluid supply unit shown.

[0021] Figure 11A It means in Figure 8 The diagram shows the sleeve used to form the fluid passage in the turbine pump of the fluid supply unit, viewed from the end face on the upper flow side towards the lower flow side.

[0022] Figure 11B yes Figure 11A GG line cross-section diagram.

[0023] Figure 12 It is observed from the upstream end face towards the downstream side. Figure 8 The image shown is a three-dimensional view of the sleeve.

[0024] Figure 13A It means Figure 8 The diagram shown is of the orifice plate used to form the reduced diameter section in the turbine pump of the fluid supply unit, viewed from the reverse side opposite the impeller.

[0025] Figure 13B yes Figure 13A HH line cross-section diagram. Detailed Implementation

[0026] The preferred embodiments of the turbine pump and fluid supply unit of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] Implementation Method 1

[0028] Figure 1 and Figure 2 This diagram illustrates a fluid supply unit comprising a turbine pump according to Embodiment 1 of the present invention. The fluid supply unit shown here is a hydraulic pump unit used in machinery to supply oil to various hydraulic devices. It has an input shaft 10 inside a unit body 3 consisting of a housing 1 and a cylinder head 2. The input shaft 10 is supported on the unit body 3 via bearings 11 and 12, with one end protruding from the housing 1 and the other end retracted inside the cylinder head 2. The input shaft 10 is rotatable about an axis C. Although not explicitly shown in the diagram, one end of the input shaft 10 is connected to a drive source such as an engine or electric motor mounted on the machinery.

[0029] In the main body 3, a cylinder 20 is disposed in the hollow portion 1a of the housing 1. The cylinder 20 is a component used to construct a positive displacement pump, i.e., a variable capacity swashplate piston pump, and is disposed in the hollow portion 1a of the main body 3 via an input shaft 10 that passes through the center. The cylinder 20 is connected to the input shaft 10 by a spline and can rotate together with the input shaft 10 around the axis C.

[0030] The cylinder body 20 has a plurality of cylinder bores 20a around the input shaft 10. Each cylinder bore 20a is formed as a hollow cylinder parallel to the axis C of the input shaft 10, and the cylinder bores 20a are arranged at equal intervals around each other in the circumferential direction. One end of each cylinder bore 20a opens on one end face of the cylinder body 20 (hereinafter referred to as the open end face 20b), while the other end opens on the other end face of the cylinder body 20 (hereinafter referred to as the sliding end face 20d) via a small-diameter cylinder port 20c. Each cylinder bore 20a is equipped with a piston 21. The piston 21 is fitted into the cylinder bore 20a in a manner that allows it to move along the axis of the cylinder bore 20a. A piston slide 22 is mounted on the end of each piston 21 that protrudes from the open end face 20b of the cylinder body 20. The piston slide 22 is connected to the piston 21 in a manner that allows it to tilt relative to the piston 21. One end of the cylinder 20 is slidably abutted against the swashplate 23 via the piston slide 22, and the other end is slidably abutted against the distributor plate 24 provided on the cylinder head 2.

[0031] The swashplate 23 has a sliding surface 23a inclined relative to the input shaft 10, which abuts against the piston slide 22 via the sliding surface 23a. The piston 21, which abuts against the sliding surface 23a of the swashplate 23 via the piston slide 22, reciprocates within the cylinder bore 20a as the cylinder body 20 rotates, based on the inclination of the sliding surface 23a. Although not explicitly shown in the figures, in the hydraulic pump unit shown in Embodiment 1, the inclination angle of the sliding surface 23a relative to the input shaft 10 can be changed. When the inclination angle of the sliding surface 23a is changed, the distance the piston 21 reciprocates relative to the cylinder bore 20a during cylinder body 20 rotation changes.

[0032] The distributor plate 24 is circular with inner and outer diameters, which can simultaneously close all the cylinder ports 20c of the cylinder body 20 that open toward the sliding end face 20d. In this embodiment 1, the sliding end face 20d of the cylinder body 20 is formed as a concave spherical surface. In order to make seamless sliding contact with it, the portion of the distributor plate 24 opposite to the sliding end face 20d of the cylinder body 20 is formed as a convex spherical surface.

[0033] In the distribution plate 24, a high-pressure port 24a and a low-pressure port 24b are provided on the circumference centered on the axis C of the input shaft 10. The high-pressure port 24a and the low-pressure port 24b are notches that penetrate the distribution plate 24 and extend in an arc shape so that multiple adjacent cylinder ports 20c can communicate with the high-pressure port 24a or the low-pressure port 24b.

[0034] On the other hand, the cylinder head 2 of the unit body 3 is provided with a discharge passage 31 and a suction passage (fluid passage) 32. One end of the discharge passage 31 is connected to the high-pressure port 24a of the distribution plate 24, and the other end (not shown) opens on the outer surface of the cylinder head 2. The opening end of the discharge passage 31, which opens on the outer surface of the cylinder head 2, is connected to an oil passage (not shown) that supplies oil to various hydraulic devices. The suction passage 32 extends radially in a straight line from the portion near the axis C of the input shaft 10, one end of which is connected to the low-pressure port 24b of the distribution plate 24, and the other end opens on the outer surface of the cylinder head 2. As can be clearly seen from the figure, the suction passage 32 is configured to have a larger inner diameter than the discharge passage 31, and it contains an impeller 34 and a sleeve 35, and its opening end has an orifice plate 36. The impeller 34, sleeve 35, and orifice plate 36 are used to form a non-positive displacement pump, i.e., a turbine pump, in the front stage of the aforementioned variable capacity swashplate piston pump.

[0035] like Figures 1 to 3B As shown, the impeller 34 has a support shaft portion 34a at its base end. The impeller 34 is rotatably mounted on the cylinder head 2 via the support shaft portion 34a, with the axis 34b (rotation axis) of the support shaft portion 34a coinciding with the axis 32a of the suction passage 32. The impeller 34 has a cylindrical portion 34d, which has an inlet 34c facing the upper opening of the suction passage 32. Inside the cylindrical portion 34d, a plurality of blade portions 34e are formed radially in a curved shape. In the portion of the cylindrical portion 34d between the blade portions 34e, a plurality of outlet ports 34f are provided in such a way that they open outward to the outer peripheral surface.

[0036] A driven gear 13 is provided at the base end of the impeller 34. The driven gear 13 is a bevel gear mounted with its shaft center coinciding with the shaft center 34b of the support shaft 34a. The driven gear 13 meshes with the transmission gear 14 located on the input shaft 10. The transmission gear 14 is a bevel gear mounted with its shaft center coinciding with the shaft center C of the input shaft 10. It functions to increase the rotational speed of the impeller 34 via the driven gear 13 when the input shaft 10 rotates. When the input shaft 10 rotates, the impeller 34 is linked according to the speed increase ratio of the transmission gear 14 and the driven gear 13, and performs the following functions: it draws oil from the suction passage 32 into the inlet 34c through multiple blades 34e, and discharges the drawn-in oil from the outlet 34f on the outer periphery and pressurizes it to the low-pressure port 24b of the distribution plate 24. This pressurization capacity increases proportionally to the square of the rotational speed of the impeller 34.

[0037] like Figure 1 and Figure 2 As shown, the sleeve 35 is installed on the upper flow side of the inner circumferential surface of the suction passage 32, thereby guiding the rotation of the impeller 34 and the flow of oil toward the inlet 34c. In this embodiment 1, a sleeve 35 having a sleeve body 35a and a flange portion 35b is used. The sleeve body 35a has a circular cross-section and is constructed with its axis 35c in a straight line, and its outer diameter is formed to fit into the interior of the suction passage 32. The flange portion 35b is formed as a flat plate extending outward from one end of the sleeve body 35a. With the sleeve body 35a inserted into the interior of the suction passage 32 and the flange portion 35b abutting against the outer surface of the cylinder head 2, a screw is screwed onto the cylinder head 2 via the flange portion 35b, thereby fixing it to the cylinder head 2.

[0038] In the inner circumferential surface of the sleeve body 35a, the downstream end portion 35d, which connects to the inlet 34c of the impeller 34, has an inner diameter approximately the same as that of the inlet 34c. Furthermore, the inner circumferential surface of the sleeve body 35a has a tapered portion 35e whose inner diameter gradually increases towards the upstream side. An outer cylindrical portion 35f is provided at the end of the sleeve body 35a closest to the downstream side, and this outer cylindrical portion 35f slidably engages with the outer circumferential portion of the end of the cylindrical portion 34d of the impeller 34.

[0039] like Figure 1 , Figure 2 , Figure 4 , Figure 5A and Figure 5B As shown, the orifice plate 36 is formed as a flat plate with a throttling orifice (reduced diameter portion) 36a in its central portion, and is mounted on the cylinder head 2 with the axis 36b of the throttling orifice 36a coinciding with the axis 35c of the sleeve body 35a. The throttling orifice 36a is formed with an inner diameter smaller than the inner diameter of the upper end of the sleeve body 35a. Thus, when the orifice plate 36 is mounted on the cylinder head 2, the orifice plate 36 protrudes towards the inner circumference of the sleeve body 35a, forming a reverse surface 40 between it and the sleeve body 35a. That is, in the suction passage 32 with the orifice plate 36 and the sleeve 35 installed, after passing through the throttling orifice 36a, the inner diameter suddenly increases on the upper side of the sleeve body 35a, and gradually decreases in the interval before reaching the impeller 34. In this embodiment 1, the throttling orifice 36a is formed on the orifice plate 36 with an inner diameter smaller than the inlet 34c of the impeller 34.

[0040] The reversing surface 40 faces the downstream side and extends orthogonally to the axis 32a of the suction passage 32. On this reversing surface 40, around the throttling orifice 36a, a plurality of reversing recesses 41 are provided at equal intervals along the circumferential direction. Each reversing recess 41 is formed as a flat recess with its inner bottom surface parallel to the reversing surface 40, and the outer peripheral end of each reversing recess 41 is substantially aligned with the inner peripheral surface of the upstream end of the sleeve body 35a. Adjacent reversing recesses 41 in the circumferential direction are separated from each other by reversing partitions 42, which are constructed to ensure a gap between them. The reversing partitions 42 are the exposed portions of the reversing surface 40, and are configured to extend radially relative to the axis 36b of the throttling orifice 36a, opening only into the throttling orifice 36a.

[0041] like Figure 1 and Figure 2 As shown, the suction pipe 50 is connected to the suction passage 32 described above via the orifice plate 36. The suction pipe 50 is connected to an oil tank (not shown). In this embodiment 1, a suction pipe 50 is connected, the inner diameter of which is larger than the throttling orifice 36a and is substantially aligned with the inner circumferential surface of the upper flow side end of the sleeve body 35a.

[0042] In the hydraulic pump unit configured as described above, if the input shaft 10 rotates based on the rotation of a drive source (not shown), the piston 21 reciprocates as the cylinder 20 rotates. Thus, oil drawn into the cylinder 20a via the suction pipe 50, the throttle orifice 36a, the sleeve body 35a, the impeller 34, and the low-pressure port 24b of the distribution plate 24 is supplied to various hydraulic devices via the high-pressure port 24a of the distribution plate 24, the discharge passage 31, and the oil passage (not shown).

[0043] During this period, in the suction passage 32, the impeller 34, which rotates at an increased speed through the drive gear 14 and the driven gear 13, functions to increase the oil pressure between the suction pipe 50 and the low-pressure port 24b of the distribution plate 24, thus improving the pump suction performance of the variable capacity swashplate piston pump.

[0044] Here, when the input shaft 10 rotates at a speed higher than its rated speed due to fluctuations in the speed of the drive source, or when the swashplate 23 of the variable capacity swashplate piston pump is set to a small tilt angle, and the downstream flow rate is less than the fluid pressurization supply capacity of the impeller 34 (hereinafter referred to as oversupply operation), the pressure in the suction passage 32 rises, and the oil passing through the discharge port 34f of the impeller 34 flows back in a swirling manner towards the sleeve body 35a through the discharge port 34f, which may cause surge. Furthermore, when the swirling backflow at the sleeve body 35a or the suction pipe 50 increases, cavitation (hereinafter referred to as backflow vortex cavitation) occurs in the backflow due to the pressure drop in the center, which may lead to a situation where stable operation is difficult to achieve.

[0045] However, according to the hydraulic pump unit described above, the backflow generated in the sleeve body 35a is reversed by contact with the orifice plate 36, thus preventing the aforementioned problems. That is, the backflow of swirling oil generated in the sleeve body 35a during oversupply operation is smoothly guided into the conical portion 35e by centrifugal force and reversed by contact with the orifice plate 36. The oil reversing at the orifice plate 36 merges with the oil flowing into the throttling orifice 36a from the suction pipe 50, accelerating the flow towards the inlet 34c of the downstream impeller 34. Therefore, even during oversupply operation, problems such as surge and operational instability due to backflow vortex cavitation can be prevented.

[0046] In particular, in embodiment 1, a reversing concave surface 41 and a reversing partition 42 are provided on the reversing surface 40 of the orifice plate 36. Therefore, the oil that abuts against the reversing concave surface 41 is restricted from circumferential diffusion by the reversing partition 42 and is transported to the throttling orifice 36a. As a result, the reverse flow of oil introduced into the conical portion 35e of the sleeve body 35a is efficiently reversed at the orifice plate 36, which can improve the pressurized oil delivery performance of the impeller 34 during overload operation and the pump suction performance in the variable capacity swashplate piston pump.

[0047] Furthermore, in Embodiment 1 described above, the inverted partition wall portion 42 of the perforated plate 36 is arranged radially, but the present invention is not limited thereto. For example, it may also be as follows: Figure 6 , Figure 7A and Figure 7B As shown in the modified example of the orifice plate 136, the reverse partition 142 is configured such that, relative to the radius of the throttling orifice (reduced diameter section) 136a passing through the shaft 136b, it gradually tilts (angle: θ) from the outer peripheral side toward the inner peripheral side in the rotation direction (arrow A) of the impeller 34 (see [reference]). Figure 7AThat is, the counterflow of oil generated in the sleeve body 35a is in a swirling shape in the same direction as the rotation direction A of the impeller 34. Therefore, by arranging the reverse partition 142 to extend along the swirling direction of this counterflow, when the oil comes into contact with the reverse concave surface 141, the flow of oil toward the center side of the throttle orifice 136a becomes smoother, and the above-mentioned effect can be expected to become more significant. In addition, the orifice plate 136 in this modified example is configured to be used instead of the orifice plate 36 of the hydraulic pump unit shown in Embodiment 1. Furthermore, the reverse concave surface 141 is the same as in Embodiment 1 in the following aspects: the reverse concave surfaces 141 are arranged on the reverse surface 140 of the orifice plate 136 at equal intervals along the circumference, and the reverse concave surfaces 141 are formed such that their inner bottom surface is flat and parallel to the reverse surface 140.

[0048] Furthermore, in the above-described Embodiment 1 and its variations, an example of a flat inner bottom surface is shown as a reverse concave surface. However, the present invention is not limited to this, and a reverse concave surface with a curved inner bottom surface may also be provided as in Embodiment 2 shown below.

[0049] Implementation Method 2

[0050] Figures 8 to 10 This diagram illustrates a fluid supply unit equipped with a turbine pump as described in Embodiment 2. The fluid supply unit shown here, like that in Embodiment 1, is a hydraulic pump unit used in working machinery to supply oil to various hydraulic devices. The main difference from Embodiment 1 lies in the structure of the sleeve 235 and the orifice plate 236. The following description primarily focuses on the differences from Embodiment 1, while common structural elements are labeled with the same symbols.

[0051] like Figures 9 to 11B As shown, the sleeve 235 is installed on the upper flow side of the inner circumferential surface of the suction passage 32, thereby guiding the rotation of the impeller 34 and the flow of oil toward the inlet 34c. In this embodiment 2, a sleeve 235 having a sleeve body 235a and a flange portion 235b is used. Figures 8 to 12 As shown, the sleeve body 235a has a circular cross-section and is constructed with the axis 235c in a straight line. Its outer diameter is formed to fit into the interior of the intake passage 32. The flange portion 235b is formed as a flat plate extending outward from one end of the sleeve body 235a. With the sleeve body 235a inserted into the interior of the intake passage 32 and the flange portion 235b abutting against the outer surface of the cylinder head 2, screws are screwed onto the cylinder head 2 via the flange portion 235b, thereby fixing it to the cylinder head 2.

[0052] The inner circumferential surface 235d of the sleeve body 235a is configured such that the end located on the upstream side has an inner diameter larger than that of the inlet 34c of the impeller 34, and is formed into a conical shape that gradually decreases in inner diameter toward the downstream side. An outer cylindrical portion 235e is provided at the end of the sleeve body 235a closest to the downstream side, and this outer cylindrical portion 235e is slidably fitted into the outer circumference of the impeller 34. A wide opening 235f is formed at the uppermost end of the sleeve body 235a, with an inner diameter larger than that of the inner circumferential surface. The downstream end portion 235g of the inner circumferential surface 235d of the sleeve body 235a, which connects to the inlet 34c of the impeller 34, is formed with an inner diameter approximately the same as that of the inlet 34c.

[0053] Furthermore, on the inner circumferential surface 235d of the sleeve body 235a, a plurality of rectifying grooves 235h are arranged side by side at equal intervals along the circumferential direction. Each rectifying groove 235h is cylindrically concave, with its respective axis extending linearly along the axis 235c of the sleeve body 235a. More specifically, each rectifying groove 235h has a concave spherical portion on its upper and lower sides. The portions of the rectifying grooves 235h in the sleeve body 235a that are spaced apart are formed by a front partition portion 235j. The front partition portion 235j is the portion exposed on the inner circumferential surface 235d of the sleeve body 235a, and it extends linearly along the axis 235c of the sleeve body 235a. As can be clearly seen from the figure, at the upper end of the rectifying groove 235h, each concave spherical portion is connected to each other at the wide opening 235f. At the downstream end of the rectifier 235h, the downstream end portion 235g, which is connected to the inlet 34c of the impeller 34, ensures a spaced-out upstream position, and the ends of each concave spherical portion are not connected to each other.

[0054] like Figure 9 , Figure 10 , Figure 13A and Figure 13BAs shown, the orifice plate 236 has a thick, circular plate portion 236a in its central part, and a thin plate portion 236b around the thick plate portion 236a. The orifice plate 236 is installed on the cylinder head 2 with the thick plate portion 236a inserted into the wide opening 235f of the sleeve 235, and the thin plate portion 236b overlapping with the flange portion 235b of the sleeve 235. A throttling orifice (reduced diameter portion) 236c is provided in the center of the thick plate portion 236a of the orifice plate 236. The throttling orifice 236c is formed with an inner diameter smaller than the inner diameter of the upper end of the sleeve body 235a. Therefore, when the orifice plate 236 is installed on the cylinder head 2, the orifice plate 236 protrudes towards the inner circumference of the sleeve body 235a, forming a reverse surface 240 inside the sleeve body 235a. That is, in the suction passage 32 with the orifice plate 236 and sleeve 235 installed, the inner diameter suddenly increases in the sleeve body 235a after passing through the throttling orifice 236c, and gradually decreases in the interval before reaching the impeller 34. In this embodiment 2, the throttling orifice 236c is formed on the orifice plate 236 with the same inner diameter as the inlet 34c of the impeller 34.

[0055] The inverted surface 240 faces the downstream side and extends orthogonally to the axis 32a of the suction passage 32. On this inverted surface 240, a plurality of inverted concave surfaces 241 are equally spaced from each other circumferentially around the throttling orifice 236c. The inverted concave surfaces 241 are formed into spherical concave shapes convex towards the upstream side. Figure 9 As shown, the sphere center 241a of each inverted concave surface 241, which serves as the bending center, is located between the throttling orifice 236c and the wide opening 235f. Each inverted concave surface 241 has an axis 236d that gradually approaches the downstream side with respect to the throttling orifice 236c. Figure 9 The part that bends in a way that is located on the upper side. For example... Figures 9 to 11B , Figure 13A and Figure 13B As shown, in the thick plate portion 236a, the portions located between each other on the reversing concave surfaces 241 are configured with reversing partition portions 242 by ensuring spacing. The reversing partition portions 242 are the portions exposed on the reversing surfaces 240, and extend radially relative to the axis 236d of the throttling orifice 236c. In this embodiment 2, the same number of reversing partition portions 242 as the front partition portions 235j are provided in the orifice plate 236 at positions corresponding to the front partition portions 235j formed in the sleeve body 235a.

[0056] In the hydraulic pump unit configured as described above, if the input shaft 10 rotates based on the rotation of a drive source (not shown), the piston 21 reciprocates as the cylinder 20 rotates. Thus, oil drawn into the cylinder 20a via the suction pipe 50, the throttle orifice 236c, the sleeve body 235a, the impeller 34, and the low-pressure port 24b of the distribution plate 24 is supplied to various hydraulic devices via the high-pressure port 24a of the distribution plate 24, the discharge passage 31, and the oil passage (not shown).

[0057] During this period, in the suction passage 32, the impeller 34, which rotates at an increased speed based on the drive gear 14 and the driven gear 13, functions to increase the oil pressure between the suction pipe 50 and the low-pressure port 24b of the distribution plate 24, thus improving the pump suction performance of the variable capacity swashplate piston pump.

[0058] Furthermore, according to the aforementioned hydraulic pump unit, even during oversupply operation such as high-speed rotation of the input shaft 10, when a swirling backflow occurs within the sleeve body 235a, the swirling backflow is suppressed by the front partition wall 235j located on the inner circumferential surface 235d, and then reversed by contact with the reversing surface 240. That is, the swirling backflow of oil generated within the sleeve body 235a during oversupply operation is rectified into axial flow by contact with the front partition wall 235j, and then reversed by contact with the reversing surface 240 of the orifice plate 236, merging with the oil flowing from the suction pipe 50 into the throttle orifice 236c, thereby accelerating the flow towards the inlet 34c of the downward-flowing impeller 34. Therefore, even during oversupply operation, problems such as surge and operational instability due to backflow vortex cavitation can be prevented.

[0059] In particular, in Embodiment 2, a cylindrical concave shape is formed between the front partition wall portions 235j as a flow straightening groove 235h, and concave spherical portions are provided at both its upper and lower ends. Therefore, regardless of the incident angle of the counterflowing oil, the swirling flow of oil can be efficiently guided into the flow straightening groove 235h and rectified into a flow along the axial direction of the sleeve 235. Furthermore, a spherical reverse concave surface 241 is provided on the reverse surface 240 of the orifice plate 236. Therefore, the flow of oil after passing through the flow straightening groove 235h can be guided towards the axis 235c of the sleeve body 235a to the downstream side without disturbing the flow of oil. This reliably prevents the counterflowing oil from crossing the orifice plate 236 and reaching the suction pipe 50 on the upstream side.

[0060] Furthermore, in the orifice plate 236, reversing partitions 242 are provided between the reversing concave surfaces 241. Therefore, oil abutting the reversing surface 240 is guided towards the axis 235c of the sleeve body 235a while its circumferential diffusion is suppressed by the reversing partitions 242. Thus, the reverse flow of oil reaching the sleeve body 235a is efficiently reversed at the orifice plate 236, improving the pressurized oil delivery performance of the impeller 34 during overload operation and the pump suction performance in the variable capacity swashplate piston pump.

[0061] Furthermore, in Embodiment 1, the modified example, and Embodiment 2 described above, an example of a turbine pump configured as a backing stage of a variable capacity swashplate piston pump was shown, but the invention is not limited to this. It can also be configured to directly supply oil to loads such as hydraulic equipment via a turbine pump containing an impeller. The fluid does not necessarily have to be oil; it can also be other liquids or gases. The drive source for driving the turbine pump can also be a hydraulic motor, turbine, windmill, or water turbine.

[0062] Furthermore, in Embodiment 1, its variations, and Embodiment 2 described above, the inner diameter of the throttling orifice is configured to be smaller than the inner diameter of the suction pipe. Therefore, the oil passing through the suction pipe is throttled as it passes through the orifice plate and then expands in the upper part of the sleeve body. Thus, according to the hydraulic pump unit described above, the oil reversed by the inverting concave surface of the orifice plate flows along with the oil expanding in the upper part of the sleeve body, thereby preventing the risk of backflow vortex cavitation. However, the relationship between the throttling orifice of the orifice plate and the inner diameter of the suction pipe is not limited to the examples described above; for example, the throttling orifice and the inner diameter of the suction pipe may be equal.

[0063] Furthermore, in Embodiment 1, the modified example, and Embodiment 2 described above, the sleeve body is configured as a conical shape in which the inner diameter of the upper flow side portion connected to the orifice plate is larger than the inner diameter of the lower flow side portion, but this is not a limitation. In addition, when the sleeve body is configured as a conical shape as in Embodiment 2, the inner diameter of the throttling orifice can be set to the same size as the impeller inlet, thereby preventing pressure loss in the oil flowing in the suction pipe.

[0064] Furthermore, in Embodiment 2 described above, a spherical concave surface for reversing is provided on the reversing surface. However, it does not necessarily have to be spherical; for example, a cylindrical concave surface for reversing that bends only from the outer periphery towards the inner periphery can also be provided. In this case, it is preferable that the axis of the cylinder, which serves as the center of bending, is located on the outer periphery of the reduced diameter portion, i.e., the throttling orifice. In addition, a rectifier groove and a front partition wall portion with a cylindrical concave surface are provided on the inner periphery of the sleeve body, but it is not necessarily required to provide a rectifier groove and a front partition wall portion. Conversely, in Embodiment 1 and its variations, a rectifier groove and a front partition wall portion can also be provided on the inner periphery of the sleeve body.

[0065] Furthermore, in Embodiment 1, the modified example, and Embodiment 2 described above, the reversing partition portions are arranged at equal intervals along the circumference, but it is not necessarily required that the reversing partition portions be arranged at equal intervals. Further, when the reversing partition portions are arranged at non-equal intervals, it is not necessarily required that the reversing concave surfaces be arranged in a manner where they are all the same size; for example, the size of the reversing concave surfaces can be configured to change according to the intervals of the reversing partition portions.

[0066] Symbol Explanation

[0067] 2 Cylinder head

[0068] 32 Inhalation route

[0069] 34 Impeller

[0070] 35 and 235 sleeves

[0071] 35a and 235a sleeve body

[0072] 235h rectifier tank

[0073] 235j Front section partition

[0074] 36, 136, 236 orifice plates

[0075] 36a, 136a, 236c throttling orifices

[0076] 40, 140, 240 reverse sides

[0077] 41, 141, 241 Reversed concave surface

[0078] 42, 142, 242 Reverse the adjacent section

Claims

1. A turbopump that pressurizes and delivers fluid to the downstream end of a fluid passage by rotating an impeller disposed in a fluid passage, characterized in that... The fluid passage has a reduced diameter section located on the upper flow side than the impeller. This reduced diameter section reduces its inner diameter by forming a reverse-flow surface facing the lower flow side. The reverse-flow surface has a reverse-flow partition section for restricting the circumferential flow of fluid. A plurality of the reversing partition sections are provided along the circumference of the fluid passage in a manner that ensures that they are spaced apart from each other. The inverted partitions are provided with inverted concave surfaces between each other, and the inverted concave surfaces are curved from the outer peripheral side of the fluid passage toward the inner peripheral side.

2. The turbine pump according to claim 1, characterized in that, The inverted partition extends radially relative to the axis of the reduced diameter section.

3. The turbine pump according to claim 1, characterized in that, The reversing partition extends relative to the radius of the axis passing through the reduced diameter section in a manner that gradually tilts towards the rotation direction of the impeller from the outer circumference to the inner circumference.

4. The turbine pump according to claim 1, characterized in that, The inverted concave surface is configured such that its bending center is located on the outer periphery side of the reduced diameter portion.

5. The turbine pump according to claim 1, characterized in that, The inverted concave surface is formed into a spherical shape.

6. The turbine pump according to claim 1, characterized in that, In the fluid passage, a front partition wall is provided on the inner circumferential surface of the portion located between the reduced diameter section and the impeller. The front partition wall is used to restrict the flow of fluid in the circumferential direction.

7. The turbine pump according to claim 6, characterized in that, The portion of the fluid passage located between the reduced diameter section and the impeller extends in a straight line along the axis of rotation of the impeller. The front partition section is located at a position corresponding to the reversing partition section. The front partition wall is provided with concave cylindrical flow channels between each other.

8. The turbine pump according to claim 1, characterized in that, The portion of the fluid passage located between the reduced diameter section and the impeller is shaped as an inclined section with its inner diameter gradually increasing towards the upstream side.

9. The turbine pump according to claim 8, characterized in that, The inner diameter of the portion of the fluid passage connected to the impeller is the same as the inner diameter of the reduced-diameter section.

10. A fluid supply unit, characterized in that, have: The turbopump according to any one of claims 1 to 9, and the positive displacement pump connected to the portion of the fluid passage located on the downstream side of the impeller.

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