Axial flow pump with inclined plate
By designing multiple cylinders and optimizing the pipeline layout in the axial piston pump, the problems of flow fluctuation and non-compact structure were solved, achieving efficient and compact liquid delivery while reducing material costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- MIXTRON SRL
- Filing Date
- 2022-01-18
- Publication Date
- 2026-06-30
AI Technical Summary
Existing axial piston pumps with tilting plates suffer from flow fluctuations and non-compact structures under high pressure, making it difficult to achieve high-efficiency fluid dynamic performance.
Design an axial piston pump with more than two cylinders arranged radially around a common axis. The delivery pipe is transverse to the cylinder central axis, and the cylinder central axes are located on both sides of an imaginary orthogonal cutting plane. This reduces the length of the delivery pipe. Combined with the optimized design of the collection channel and suction channel, the volume and surface area of the pumping chamber are reduced.
It effectively reduces flow fluctuations, improves pump compactness and fluid dynamics efficiency, reduces material costs, decreases pump size and stress, and achieves efficient liquid delivery.
Smart Images
Figure CN116888362B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an axial piston pump, and more particularly to an axial piston pump with a tilting plate for use with high pressure and low viscosity fluids. Background Technology
[0002] An axial piston pump with a tilting plate typically includes a head in which a plurality of cylinders arranged parallel to each other are formed at least partially, and a piston slides in each cylinder to pump liquid. The cylinders are connected to a source of liquid to be pumped through a suction channel, which typically includes a main pipe and a plurality of branch pipes that provide fluid communication between the main pipe and the cylinders.
[0003] Axial flow pumps with two pistons and inclined plates for high pressure are known, which are relatively simple to design and manufacture (especially in terms of the construction and design of the suction and delivery channels), but on the other hand, they exhibit non-negligible flow fluctuations during operation.
[0004] The object of this invention is to enable an axial piston pump to reduce flow oscillations during delivery, while simultaneously possessing a compact and efficient structure from a hydrodynamic perspective, all within the scope of a reasonable and cost-effective solution. This object is achieved by the features of the invention indicated in the independent claims. The dependent claims summarize the preferred and / or particularly advantageous aspects of the invention. Summary of the Invention
[0005] In particular, the present invention provides a rotary tilting plate axial piston pump for pumping liquids, the axial piston pump comprising:
[0006] head,
[0007] Multiple cylinders, more than two in number, are formed in the head. The cylinders have axes parallel to each other and are arranged radially about a common axis parallel to the cylinder axes.
[0008] Multiple pistons, each slidably inserted into a corresponding cylinder of the plurality of cylinders, are used for pumping liquid.
[0009] Multiple delivery pipes are formed in the head, each of which extends directly from a corresponding cylinder to a corresponding delivery valve and is arranged transversely to the central axis of the corresponding cylinder.
[0010] The head has a first side and a second side, the second side being opposite to the first side relative to an imaginary orthogonal cutting plane S, the imaginary orthogonal cutting plane S including the common axis and parallel to the central axis of the cylinder.
[0011] The plurality of cylinders includes a first arrangement of cylinders and a second arrangement of cylinders. The central axis of the first arrangement of cylinders lies between the first side and the imaginary orthographic plane, and the central axis of the second arrangement of cylinders lies between the second side and the imaginary orthographic plane.
[0012] The delivery pipe extending from the cylinder in the first arrangement extends from the corresponding cylinder toward the first side, and the delivery pipe extending from the cylinder in the second arrangement extends from the corresponding cylinder toward the second side.
[0013] This solution provides an axial piston pump with reduced flow fluctuations during delivery, as it incorporates more than two cylinders. From a hydrodynamic perspective, this axial piston pump is compact, robust, and particularly efficient. Specifically, these features allow for minimizing the length of the delivery conduit in a pump with more than two cylinders, thereby reducing the volume and surface area of the pumping chamber, which, as is known, comprises a portion of the cylinder, the delivery conduit, and the suction conduit, and is subjected to cyclic loads that generate pressure pulsations due to the pumping of the liquid. Minimizing the volume and surface area subjected to such pulsations allows for a reduction in pump size and / or, within the same pump size, allows for the use of less expensive materials, i.e., materials with lower resistance to pulsations. This advantage is particularly evident, for example, compared to prior art pumps where the delivery conduit opens from one side of the pump, resulting in a particularly long delivery conduit for the cylinder furthest from that side and subjecting it to significant stress from pressure pulsations.
[0014] Obviously, if the cylinder's own central axis is on the imaginary cutting plane, then it will be irrelevant whether the corresponding delivery pipe extends in the direction of the first side or the second side.
[0015] According to one aspect of the invention, the pump may include a collection channel configured to collect liquid discharged from the delivery valves, the collection channel being formed in the head and including a section along an annular path in fluid communication with all delivery valves.
[0016] In this way, the pump is particularly compact.
[0017] According to another aspect of the invention, the pump may include an intake valve for each cylinder, wherein each intake valve is housed in a seat provided with an outlet nozzle that is in direct fluid communication with the internal volume of the cylinder.
[0018] In this way, the volume of the pumping chamber can be further reduced, for example, because the proposed solution essentially allows for the elimination of the suction pipe between the cylinder and the suction valve.
[0019] According to another aspect of the invention, the pump may include a suction passage for a liquid to be pumped, the suction passage being provided with a main pipe and a plurality of branch pipes, each of the branch pipes being adapted to fluidly communicate the main pipe with a corresponding cylinder among the plurality of cylinders, wherein the main pipe is located between the central axes of the plurality of cylinders.
[0020] This solution provides an axial piston pump that reduces flow fluctuations during delivery, is robust and compact, and is particularly efficient in terms of fluid dynamics.
[0021] According to one aspect of the invention, an inlet channel may be formed in the head.
[0022] In this way, the axial compactness of the pump is improved, and the assembly operation is faster.
[0023] Preferably, the entrance channel can be formed entirely within the head.
[0024] According to another aspect of the invention, the main pipe can be equidistant from all cylinders.
[0025] In this way, the uniform distribution of the liquid is ensured.
[0026] According to another aspect of the invention, each branch pipe may include a pair of opposing walls, each wall having a corresponding curved surface, each curved surface having a single transverse axis of curvature relative to a plane perpendicular to the central axis of the cylinder.
[0027] Thanks to this solution, branch pipe manufacturing is simpler and cheaper than existing technologies.
[0028] For example, each of the curved surfaces includes a recessed portion that turns toward a recessed portion of another curved surface. Attached Figure Description
[0029] Other features and advantages of the invention will become clear from the following description provided by way of non-limiting embodiments and with the aid of the accompanying drawings.
[0030] Figure 1 This is a front view of the axial piston pump according to the present invention.
[0031] Figure 2 yes Figure 1 The axial piston pump in the diagram is shown in the sectional view of plane II-II.
[0032] Figure 3 It is based on Figure 2 Sectional view of plane III-III.
[0033] Figure 4 It is based on Figure 2A sectional view of plane IV-IV.
[0034] Figure 5 yes Figure 1 A top view of an axial piston pump.
[0035] Figure 6 yes Figure 5 The axial piston pump in the middle is shown in the sectional view of plane VI-VI. Detailed Implementation
[0036] With particular reference to these figures, 1 generally indicates an axial piston pump for high pressure, preferably suitable for pumping low-viscosity liquids, such as water.
[0037] For example, as better described below, the axial piston pump 1 is of the type equipped with a fixed tilting rotary plate. Furthermore, it is of the type equipped with an automatic valve and a delivery valve for regulating the pumping flow rate.
[0038] As in Figure 6 As can be seen in the cross-section, the axial piston pump 1 may include a base 5 and a rotating tilting plate 10, which is adapted to receive rotational motion from a drive shaft outside the axial piston pump 1.
[0039] The inclined plate 10 is housed in the base 5 and is rotatably associated with the base relative to the pivot axis A, and includes, for example, a flat annular surface 15 located on a plane inclined relative to the pivot axis A. In particular, the inclined plate is rotatably associated with a flange 20 by a bearing, the flange 20 being rigidly fixed (e.g., bolted) to the base 5.
[0040] The base can be fixed to the motor or frame by means of the flange, and the external drive shaft is rotatably associated with the motor or frame.
[0041] The axial piston pump 1 includes a head 25 fixed to the base 5, i.e., fixed to the base 5 without residual degrees of freedom, and a plurality of cylinders 30, i.e. circular straight holes, are formed in the head 25, each cylinder 30 having a corresponding central axis C.
[0042] The head 25 can be formed as a single integral body, i.e., it can be obtained by machining a single body, which is obtained by solidifying a single casting or by injecting material into a mold. In the illustrated embodiment, at least a portion of the head of the cylinder is formed of a polymer material.
[0043] The number of cylinders 30 in the plurality of cylinders 30 is greater than two, that is, at least three. In the illustrated embodiment, the number is greater than three, for example five. This is the best trade-off between flow regularity and pump complexity.
[0044] All cylinders are arranged so that their respective central axes are parallel to each other.
[0045] For example, the cylinders are arranged radially along a common axis, and the axis of each individual central cylinder is parallel to this common axis. Furthermore, they are placed at equal distances from each other and at the same distances relative to the common axis. In other words, the cylinders (i.e., the central axes of the cylinders) are arranged at angles at equal distances from each other along an imaginary circle centered on the common axis and located in a plane perpendicular to the common axis.
[0046] In the illustrated embodiment, the common axis of cylinder 30 is coaxial, that is, it coincides with the pivot axis A.
[0047] The cylinder is spatially fixed relative to the base.
[0048] Again in the illustrated embodiment, there are five cylinders, the central axis of which passes through the vertices of an imaginary regular pentagon located on a plane perpendicular to the central axis of the cylinder.
[0049] All cylinders 30 have the same diameter.
[0050] Preferably, the cylinders 30 are through cylinders, meaning they pass through the head 25 from one side to the other. Specifically, the head may include a first surface 35 (e.g., flat) in contact with the base 5 and an opposing second surface 40 away from the base 5 (see also...). Figure 6 ).
[0051] The cylinder 30, i.e., the cylinder bore forming the cylinder, can extend from the first face 35 to the second face 40. Specifically, each cylinder 30 extends from the first face 35 to the second face 40, thereby forming a first opening 45 in the first face 35 and a second opening 50 in the second face 40. However, it is not excluded that in embodiments not shown, the bore forming the cylinder can be shaped as a blind bore that only passes through the first face forming the first opening 45.
[0052] The head 25 includes a side surface 60 (integral annular / tubular) that extends from the first surface to the second surface and connects them.
[0053] The first surface 35 and the second surface 40 can be parallel to each other, for example, also transverse to, and preferably perpendicular to, the central axis of the cylinder 30.
[0054] A first side 61 and a (diameter-directed) opposing second side 62 can be identified within the head, for example, as part of a side surface 60. In other words, the side surface comprises the first side and the second side. In practice, the first side and the second side are opposing portions of the side surface.
[0055] However, it is not excluded that in embodiments not shown, the first side and the second side may also be part of the second surface 40. That is, the side surface (or the side surface and the second surface) may include the first side and the opposite second side. In practice, the first side and the second side may be opposite portions of the surface formed by the side surface and the first surface.
[0056] The second side 62 is opposite to the first side 61 relative to the imaginary orthogonal cutting plane S, which includes a common axis C (i.e., the pivot axis A) and is parallel to the central axis of the cylinder.
[0057] The first side 61 and the second side 62 are substantially equidistant from the imaginary orthogonal cutting plane S.
[0058] In the head, that is, in the side surface of the head (or possibly in the second surface in the same manner as described above), a third side 63 and a fourth side 64 opposite to each other can also be identified, the third side 63 and the fourth side 64 connecting the first side from the opposite end of the second side to the second side and intersecting with the imaginary orthogonal cutting plane S.
[0059] In general, in the illustrated embodiment, the first side, the second side, the third side, and the fourth side constitute the side surface 60.
[0060] In embodiments not shown, these sides may generally form the side surfaces of the head and the (peripheral) portion of the second surface.
[0061] The plurality of cylinders includes a first arrangement of cylinders and a second arrangement of cylinders. In the first arrangement of cylinders, each cylinder is arranged such that its own central axis is between a first side 61 and an imaginary orthographic plane S. In the second arrangement of cylinders, each cylinder is arranged such that its own central axis is between a second side 62 and an imaginary orthographic plane S.
[0062] In this embodiment, the plurality of cylinders are completely re-divided between the first arranged cylinders and the second arranged cylinders.
[0063] Specifically, the first arrangement of cylinders includes three cylinders, and the second arrangement of cylinders includes two cylinders.
[0064] However, it is not excluded that in alternative embodiments not shown, the plurality of cylinders may consist of a first arrangement of cylinders, a second arrangement of cylinders, and a third arrangement of cylinders, wherein in the third arrangement of cylinders, each cylinder is arranged such that its central axis lies on an imaginary orthographic plane.
[0065] Furthermore, in alternative embodiments (not shown) where three cylinders are present, the first arrangement of cylinders may include two cylinders, and the second arrangement of cylinders may include one cylinder.
[0066] In practice, each arrangement of cylinders between the first and second cylinders must contain at least one cylinder.
[0067] The axial piston pump 1 may include a plurality of clamping screws 65, for example, the number of which is at least equal to the number of cylinders 30, which are configured to secure the head 25 to the base 5 and are inserted into as many through holes 70 as possible formed in the head 25.
[0068] For example, the through holes 70 are arranged at an angle at equal distances along an imaginary circumference centered on the common axis of the cylinder 30.
[0069] In the illustrated embodiment, where both the head and base are formed of a polymer material, the pump includes a cap 71, for example, formed of a metal material, which contacts a second surface of the head, and an insert 300 with internal threads is present in the base, which allows tightening of a clamping screw 65 to secure the head between the cap and the base, thereby rigidly connecting the base, head, and cap therebetween. However, the presence of a cap is not excluded if the pump is formed entirely of metal.
[0070] The axial piston pump 1 includes a plurality of pistons 75, each piston 75 being adapted to slide in a corresponding cylinder 30 and driven by a tilting plate 10 to pump fluid.
[0071] Specifically, as the tilting plate 10 rotates, the piston 75 slides between the top dead center position and the bottom dead center position along the central axis of the corresponding cylinder 30.
[0072] In the illustrated embodiment, each piston 75 has a first axial end and an opposing second axial end, the first axial end being inside the corresponding cylinder 30, and the second axial end protruding from the cylinder inside the base 5 and via a corresponding elastic element 90 (see...). Figure 6 It maintains contact with the annular guide 95, which rests (e.g., by inserting an axial roller bearing) on the flat annular surface 15 of the inclined plate 10.
[0073] Each elastic element 90 has a first end connected to the base 5 and a second end connected to the piston 75 (e.g., near the second end).
[0074] The axial piston pump 1 includes a plurality of annular washers 105 adapted to sealably surround a corresponding piston 75 to prevent fluid communication between the corresponding cylinder and the base 5. For example, some of these annular washers are housed in an annular body 106, which is partially housed in a first receiving seat formed in the head and partially housed in a second receiving seat formed in the base.
[0075] The annular body also has another pair of seats, each for a corresponding O-ring, which is inserted between the first receiving seat of the annular body and the annular body.
[0076] In addition, the axial piston pump 1 may include a plurality of annular guide surfaces 110 formed in the base, each annular guide surface 110 being adapted to guide a corresponding piston 75 sliding along a corresponding sliding axis in the cylinder.
[0077] In addition, pump 1 includes a delivery valve 120 for each cylinder 30, such as an automatic type delivery valve 120 (see...). Figure 4 and Figure 6 ).
[0078] An automatic valve is defined as a valve that is configured to open automatically when a preset pressure difference is reached between two environments separated by the valve, thereby allowing fluid communication between the two environments to which it is inserted. Specifically, an automatic valve does not utilize an electromechanical operating mechanism, but only utilizes the pressure difference.
[0079] Each delivery valve includes a gate 125 that is in contact with an abutment surface 130 surrounding a through-hole 135 via a resilient element to hermetically close the through-hole. When the gate is in a position away from the abutment surface, fluid pumped by the piston passes through the through-hole.
[0080] When the pressure inside the cylinder rises above a predetermined value, the pressure of the liquid overcomes the force of the elastic element, moves the gate, and allows the liquid to pass through the through hole.
[0081] Each of the delivery valves 120 is housed in a corresponding receiving seat 140 obtained in the head 25.
[0082] The receiving seat 140 of the delivery valve is shaped similarly to a recess formed in the head and has an opening facing outwards from the head through which the valve can be inserted and withdrawn.
[0083] These openings (and thus essentially recesses) in the receiving seat of the delivery valve are formed (only) on the first or second side.
[0084] The fact that the housing 140 is formed in the first side 61 or the second side 62 is defined by whether the corresponding cylinder 30 controlled by the delivery valve present in the housing is part of the cylinder of the first arrangement or the cylinder of the second arrangement.
[0085] The receiving seat 140 of the delivery valve 120 for the cylinder of the first arrangement is formed at the first side 61, that is, at a portion of the side surface (and / or the second surface) of the first side, while the receiving seat 140 of the delivery valve 120 for the cylinder of the second arrangement is formed at the second side 62, that is, at a portion of the side surface (and / or the second surface) of the second side.
[0086] Pump 1 includes a plurality of delivery pipes 145 formed in the head, each delivery pipe 145 extending directly from a corresponding cylinder 30 to a corresponding delivery valve 120, i.e. to the receiving seat 140 of the corresponding delivery valve 120.
[0087] Each delivery pipe has (only) a first opening formed in the corresponding cylinder 30 and a corresponding second opening formed in the receiving seat of the corresponding delivery valve.
[0088] Each delivery pipe 145 is arranged such that it has a longitudinal axis arranged transversely to the central axis of the corresponding cylinder, for example, a longitudinal axis arranged perpendicular to the central axis of the corresponding cylinder.
[0089] In addition, each delivery pipe 145 (i.e., the corresponding longitudinal axis) is also perpendicular to the imaginary orthogonal cutting plane.
[0090] The longitudinal axis refers to the axis that extends in the direction of maximum extension of the pipe, or alternatively, in the case of a submerged pipe, it extends along the flow direction inside the pipe, i.e., it passes through both the first opening and the second opening.
[0091] In the illustrated embodiment, each delivery pipe is, for example, cylindrical, and the central axis of the cylindrical inner surface of the pipe coincides with the longitudinal axis of the pipe.
[0092] Regardless of the exact construction of the delivery pipes, the delivery pipe 145 extending from the cylinder in the first arrangement of cylinders extends from the corresponding cylinder toward the first side, and the delivery pipe extending from the cylinder in the second arrangement of cylinders extends from the corresponding cylinder toward the second side.
[0093] If a third cylinder arrangement exists, the corresponding delivery pipe extending toward the first side or toward the second side is equivalent.
[0094] The pump has a corresponding pumping chamber for each cylinder 30, the volume of which is defined at least in part by the space between the cylinder and the piston and by the volume of the delivery conduit. Therefore, by minimizing the extension of the conduit as much as possible, the direction of the conduit extension allows for the volume of the pumping chamber.
[0095] For the first arrangement of cylinders, the first opening of each delivery pipe 145 is preferably formed in the portion of the corresponding cylinder near the first side, and for the second arrangement of cylinders, the first opening of each delivery pipe 145 is preferably formed in the portion of the corresponding cylinder near the second side.
[0096] If a third arrangement of cylinders exists, the first opening is preferably formed in the portion of the cylinder closest to the side where the corresponding seat for the delivery valve has been determined to be formed.
[0097] In the illustrated embodiment, each delivery conduit 145 is defined at least partially by a hole, for example, entirely by a hole that passes through the recess of the corresponding receiving seat 140 and intersects with the corresponding cylinder 30.
[0098] These delivery pipes are preferably located on a single plane, for example, perpendicular to the central axis of the cylinder.
[0099] Pump 1 may include a plurality of delivery plugs 150, each delivery plug 150 for each opening of a recess in a receiving seat, the plurality of delivery plugs 150 being configured to hermetically close the opening of the receiving seat, the opening allowing the receiving seat to communicate with the environment outside the pump and keeping the corresponding delivery valve locked in its respective receiving seat.
[0100] These plugs are screwed into, for example, the cylinder head.
[0101] Therefore, in the illustrated embodiment, where the head is formed of a polymer material, the pump includes a threaded metal insert to allow the corresponding plug to be screwed on.
[0102] Special Reference Figure 3 Pump 1 may include a collection channel configured to collect liquid discharged from the delivery valve. In particular, the channel is in direct fluid connection with a portion of each receiving seat 140 of the respective delivery valve (and thus in the absence of an insert valve), especially with a portion of that seat downstream of the gate 125 relative to the direction of the pumped fluid.
[0103] The collection channel is formed entirely in the head, for example, and includes a section along an annular path that is in fluid communication with all delivery valves, i.e., constituted by this section.
[0104] Specifically, the segment forming the annular path is radially outside the cylinder 30 relative to the common axis. In other words, it externally surrounds multiple cylinders.
[0105] In the illustrated embodiment, the segment includes a first channel 155, which is, for example, straight and located in a plane transverse to (preferably perpendicular to) the common axis of the cylinder, and this first channel is in fluid communication with all (all) receiving seats 140 of the delivery valve 120 at the first side 61. Preferably, the first channel intersects with the receiving seat (i.e., the recess of the seat) (as in...). Figure 6 As can be seen in the cross-section, in this way, it is not necessary to form a special conduit to connect the receiving seat to the first channel. In detail, the first channel is formed as a (single) through hole that intersects the receiving seat (i.e., the recess of the seat) from one side to the other through the head (e.g., its side surface 60).
[0106] Therefore, the first channel 155 forms two openings in the head, wherein at least one opening (e.g., only one opening) is hermetically sealed by a plug 160 fixed (threaded connection) to the head.
[0107] The opposite opening can have a quick-connect mechanism or threads for connecting to the external delivery pipe of the pump.
[0108] In the illustrated embodiment, the section further includes a second channel 165, which is, for example, straight and located in a plane transverse to (preferably perpendicular to) the common axis of the cylinder, and is in fluid communication with all (all) receptacles 140 of the delivery valve 120 at the second side 62. Preferably, the second channel intersects the receptacle (i.e., the recess of the receptacle) in such a way that it is not necessary to form a special conduit to connect the receptacle to the second channel. Specifically, the second channel is formed as a (single) through-hole that intersects the receptacle 140 (i.e., the recess of the receptacle) from one side to the other through the head (e.g., its side surface 60).
[0109] Therefore, the first channel 165 forms two openings in the head, at least one of which is hermetically sealed by a plug 160 fixed (threaded) to the head. For example, both openings are sealed by corresponding plugs 160.
[0110] Still in the illustrated embodiment, the segment further includes a third channel 175 and a fourth channel 180, for example, linear, the third channel 175 and the fourth channel 180 formed in the head, and connecting the first channel 155 to the second channel 165 through diametrically opposite portions of the channels relative to a plane perpendicular to the imaginary orthographic plane and containing the common axis of the cylinder. In practice, the second and third channels are transverse to and intersect the imaginary orthographic plane S.
[0111] Similar to the first and second channels, the third and fourth channels are each formed as (single) blind holes in the head, and these blind holes form openings closed by suitable plugs 160.
[0112] These blind holes allow the third and fourth channels to intersect directly with the first and second channels.
[0113] It cannot be ruled out that the third and fourth channels could be formed as through holes passing through the head from one side to the other.
[0114] Furthermore, in an alternative, less preferred embodiment, due to its greater complexity, the third and fourth channels could be replaced by a tee pipe external to the pump, having a first inlet connected to the first channel, a second inlet connected to the second channel, and an outlet. In this case, the second channel must be closed only in one of its two openings in the head to allow the connection of the tee pipe.
[0115] Pump 1 includes an automatic type suction valve 185 for each cylinder 30.
[0116] Each intake valve 185 is housed in a housing 190 formed in the head and is provided, for example, with an outlet nozzle 195 in direct fluid communication with the internal volume of the cylinder 30. Preferably, the outlet nozzle may be formed in the side surface of the cylinder 30.
[0117] In the illustrated embodiment, the receiving seat 190 of the intake valve 185 is formed inside the cylinder 30, for example, near the second side. For example, the outlet of the receiving seat has a central axis parallel to, and preferably coaxial with, the central axis of the corresponding cylinder.
[0118] In alternative embodiments, it is not excluded that the intake valve may not be housed in the cylinder 30, but may be positioned in a specific seat formed in the head and fluidly communicated with the cylinder via a specific intake conduit.
[0119] However, in this case, the pumping chamber must have a larger volume because it will also include the volume of the suction pipe, that is, the volume of the suction pipe extending from the cylinder to the suction valve.
[0120] Returning to the illustrated embodiment, each suction valve 185 includes a gate 200 that maintains contact with an abutment surface 205 surrounding a through-hole 210 via an elastic element to hermetically close the through-hole. When the gate is in a position away from the abutment surface, fluid drawn in by the piston passes through the through-hole.
[0121] When the pressure inside the cylinder drops below a predetermined value, the pressure of the liquid overcomes the force of the elastic element, moves the gate, and allows the liquid to pass through the through-hole. This through-hole is, for example, coaxial with the outlet 195 of the intake valve's housing 190.
[0122] The receiving seat 190 of the suction valve 185 is shaped like a recess formed in the head and is provided with an opening facing outward of the head through which the valve can be inserted and withdrawn.
[0123] These openings (and thus essentially recesses) of the seat of the delivery valve are formed in another facade and correspond to the second opening of the cylinder.
[0124] The pump includes a perforated spacer 215 that allows liquid to enter and exit the suction valve and is located between the suction valve and a cover, the cover being configured such that when the cover is in place, the spacer is pushed against the suction valve and holds the suction valve in place.
[0125] Pump 1 includes a suction passage for dispensing liquid to be pumped to cylinder 30. Specifically, when the pump is in use, the suction passage is in direct fluid communication with a portion of cylinder 30 upstream of suction valve 185 (i.e., a portion of housing 190 upstream of suction valve) relative to the direction of fluid flow. Specifically, the suction passage communicates with the portion of cylinder 30 (i.e., the portion of housing 190) at a perforated spacer.
[0126] The channel for drawing in the liquid to be pumped includes a main pipe 220, which is formed in the head and preferably extends along a longitudinal axis.
[0127] The main pipe 220 is located between the central axes of the cylinders 30, that is, the main pipe 220 is contained in the space between all the central axes of the cylinders 30, i.e., the main pipe 220 is located in the space between all the cylinders of the head. More specifically, the main pipe 220 is accommodated in the space between the central axes of each pair of cylinders 30 that are diagonally opposite to the common axis.
[0128] For example, the main pipe 220 is equidistant from all the central axes of the cylinder 30, that is, the longitudinal axis of the main pipe 220 is equidistant from all the central axes of the cylinder 30.
[0129] The longitudinal axis of the main pipe 220 is, for example, parallel to the central axis of the cylinder 30, and preferably also coaxial with the common axis of the cylinder 30.
[0130] In the illustrated embodiment, the main conduit 220 is located between the cylinders 30, that is, the main conduit 220 is contained within the space between all the cylinders. Alternatively, it is located between each pair of cylinders 30 in the plurality of cylinders 30.
[0131] Furthermore, the main pipe 220 preferably has a cylindrical shape. However, a tapered shape is not excluded in alternative embodiments.
[0132] For example, the main pipe 220 can be substantially shaped as a blind hole that extends from the second face 40 of the head 25 along its own longitudinal axis toward the interior of the head 25.
[0133] The suction passage also includes multiple branch pipes 225, one branch pipe 225 for each cylinder 30. The branch pipes 225 are formed in the head and are configured to place the main pipe 220 in fluid connection with the cylinder 30, particularly the portion of the cylinder 30 that is located upstream of the suction valve 185 relative to the direction of fluid flow when the pump is in use.
[0134] In the illustrated embodiment, each branch pipe 225 has a pair of sidewalls 230 opposite to and facing each other, and each sidewall 230 includes at least a curved surface having a single axis of curvature transverse to a plane perpendicular to the central axis of the cylinder 30, preferably, the axis of curvature is parallel to the central axis of the cylinder 30.
[0135] For example, the curved surfaces define corresponding recesses that turn to each other. Furthermore, the curved surfaces of the sidewalls of each branch pipe 225 are symmetrical about an axis of symmetry containing the central axis of the corresponding cylinder 30.
[0136] The sidewalls may also include more curved surfaces, each with a single axis of curvature as described above.
[0137] In the illustrated embodiment, the pair of curved surfaces extend from the main pipe 220 to the corresponding cylinder 30, i.e., the curved surfaces completely define the corresponding sidewall 230.
[0138] Each branch pipe 225 may also include an additional pair of sidewalls 235, preferably the additional pair of sidewalls 235 being flat and opposite to each other. Each of the additional pair of sidewalls is configured to extend from sidewall 230 to the opposite sidewall 230.
[0139] For example, the sidewalls 230 of the additional pair of sidewalls 235 are each located in a transverse plane relative to the central axis of the cylinder 30, preferably perpendicular to the central axis of the cylinder 30.
[0140] The pair of sidewalls 230 and the additional pair of sidewalls 235 form corresponding branch pipes 225.
[0141] In other embodiments, it is not excluded that branch pipes may have a circular cross-section transverse to their own longitudinal axis, that is, they are cylindrical pipes, or may be at least partially defined by holes extending from the main pipe 220 to the side surface 60 of the head 25.
[0142] Pump 1 may also include a return conduit 240, which is independent of branch conduits 225 that provides fluid communication between cylinder 30 and main conduit 220. Each return conduit 240 leads to a portion of a corresponding cylinder that is axially included between a pair of annular sealing gaskets 105 and passes through an annular body.
[0143] In this way, the pressurized liquid leaking from the annular gasket in the cylinder can be directly carried into the intake passage.
[0144] The operation of the above pump is as follows.
[0145] After the tilting rotary plate moves, simultaneously, in one or more cylinders, the movement of the corresponding piston toward the bottom dead center creates a vacuum in the pumping chamber, which in turn causes the corresponding delivery valve to close and the corresponding suction valve to open. Therefore, liquid is drawn in from the main pipe 220 and passes through the corresponding branch pipes, through the corresponding suction valve, and into the corresponding pumping chamber. Upon reaching the bottom dead center, the piston rises toward the top dead center due to the thrust of the rotary plate, thereby creating overpressure in the pumping chamber. This overpressure closes the suction valve and opens the delivery valve. Therefore, fluid flows through the delivery valve into the corresponding collection pipe of the valve, where it travels along a portion of an annular section and then exits from an opening connected to a pipe outside the pump.
[0146] The present invention, conceived in this way, is easy to modify and vary, and all modifications and variations fall within the scope of the present invention.
[0147] Furthermore, all details can be replaced by other technically equivalent components.
[0148] In practice, the materials used, as well as the shape and size as appropriate, may be any materials, shapes and sizes required, without thereby departing from the scope of protection of the appended claims.
Claims
1. A rotary tilting plate axial piston pump (1) for pumping liquids, comprising: Head (25); Multiple cylinders (30) are formed in the head (25) in a number greater than two, the multiple cylinders (30) having axes (C) parallel to each other, and the cylinders are arranged radially about a common axis (A) parallel to the axes of the cylinders. Multiple pistons (75), each piston being slidably inserted into a corresponding cylinder (30) of the multiple cylinders (30) for pumping liquid; Multiple delivery pipes (145) are formed in the head (25), each of the multiple delivery pipes (145) extending directly from the corresponding cylinder (30) to the corresponding delivery valve (120) and arranged transversely to the axis (C) of the corresponding cylinder; The head (25) has a first side (61) and a second side (62), the second side (62) being opposite to the first side (61) with respect to an imaginary orthographic plane (S), the imaginary orthographic plane (S) including the common axis (A) and parallel to the axis (C) of the cylinder (30). The plurality of cylinders (30) includes a first arranged cylinder and a second arranged cylinder. The axis (C) of the first arranged cylinder lies between the first side (61) and the imaginary orthographic plane (S), and the axis (C) of the second arranged cylinder lies between the second side (62) and the imaginary orthographic plane (S). The delivery pipe (145) extending from the cylinder (30) in the first arrangement of cylinders extends from the corresponding cylinder (30) toward the first side (61), and the delivery pipe extending from the cylinder in the second arrangement of cylinders extends from the corresponding cylinder (30) toward the second side (62). The pump includes a channel for drawing in liquid to be pumped, the channel including a main pipe (220) and a plurality of branch pipes (225), each of the branch pipes being adapted to fluidly communicate the main pipe (220) with a corresponding cylinder (30) in the plurality of cylinders. The main pipe is located between the axes of the plurality of cylinders. Each branch pipe includes a pair of opposing walls (230), each wall having a corresponding curved surface, each curved surface having a single transverse axis of curvature relative to a plane perpendicular to the central axis of the cylinder.
2. The axial piston pump (1) according to claim 1, comprising a collection channel configured to collect liquid discharged from the delivery valve (120), the collection channel being formed in the head (25) and including sections (155, 165, 175, 180) along an annular path in fluid communication with all delivery valves.
3. The axial piston pump (1) of claim 1, comprising a suction valve (185) for each cylinder (30), wherein, Each intake valve is housed in a housing (190), which is provided with an outlet (195) in direct fluid communication with the internal volume of the cylinder.
4. The axial piston pump (1) according to claim 1, wherein, An entrance channel is formed in the head (20).
5. The axial piston pump (1) according to claim 4, wherein, The main pipe (220) is equidistant from all cylinders (30).