Axial piston pump, arrangement and aircraft

Abstract

The present invention relates to an axial piston pump, in particular for an aircraft, with a pivoting cradle bearing and a pivoting cradle, wherein the pivoting cradle is mounted in the pivoting cradle bearing, wherein a bearing gap is provided between the pivoting cradle bearing and the pivoting cradle, wherein a channel is provided through which a medium, in particular hydraulic fluid, can flow from an outlet located on the high-pressure side of the axial piston pump to the bearing gap, wherein the channel runs at least partially through the pivoting cradle bearing.

Description

[0001] The present invention relates to an axial piston pump, in particular for an aircraft, with a pivoting cradle bearing and a pivoting cradle, wherein the pivoting cradle is mounted in the pivoting cradle bearing, wherein a bearing gap is provided between the pivoting cradle bearing and the pivoting cradle, wherein a channel is provided through which a medium, in particular hydraulic fluid, can flow from an outlet located on the high-pressure side of the axial piston pump to the bearing gap.

[0002] Common axial piston pumps can have a nominal pressure of up to approximately 345 bar (or up to approximately 5000 psi). In confined spaces within an aircraft, for example, when the axial piston pump is located in a wing, the requirements for the strength of the pump's components increase accordingly.

[0003] To enable a variable flow rate from the axial piston pump, the slewing cradle is mounted in two bearing shells of the slewing cradle bearing. To reduce friction and thus increase service life, the slewing cradle is hydrostatically mounted or unloaded within its bearing.

[0004] This requires a supply of hydraulic fluid from the high-pressure side of the axial piston pump to the slewing rocker bearing.

[0005] In known axial piston pumps, the connection from the high-pressure side to the slewing rocker bearing is realized by means of one or more connecting bores in the slewing rocker, over which the pistons with sliding shoes pass.

[0006] One such known axial piston pump from the prior art is in Fig. 2 shown.

[0007] The axial piston pump made of Fig. The axial piston pump comprises a cylinder Z in which pistons K are arranged, each having a sliding shoe. The pump also includes a pivoting cradle 2 mounted in a pivoting bearing 1 of the pump. The pivoting bearing 1 has two bearing shells 1a. A bearing gap 3 for hydrostatic support of the pivoting cradle 2 is provided between the bearing shells 1a and the pivoting cradle 2. A connecting bore 2a is provided in the pivoting cradle.In operation of the axial piston pump, the cylinder Z and the pistons K rotate around an axis, with the sliding shoes passing over the connecting bore 2a and, with each pass, a connection is established between the high-pressure side of the axial piston pump and the bearing gaps 3 through the respective piston K and its sliding shoe and the connecting bore 2a, as soon as the passages present in the piston K and the sliding shoe are aligned with the connecting bore 2a, whereby a hydrostatic bearing of the pivoting cradle 2 takes place.

[0008] The flow through the connecting bore 2a and the pressure in the bearing gaps 3 pulsate strongly, since hydraulic fluid only flows into the bearing gaps 3 when a piston K with sliding shoe passes over the connecting bore 2a and a connection exists between the high-pressure side and the bearing gaps 3.

[0009] The sliding shoes are also hydrostatically mounted or relieved on the swivel cradle 2, whereby the respective bearing gap of these mountings is also supplied with hydraulic fluid from the high-pressure side through the passages in the piston K and the sliding shoe.

[0010] The relief of the sliding shoes and the relief of the swivel cradle are thus linked. Both the sliding shoes and the swivel cradle have relief grooves adjacent to their respective bearing gaps. Due to this linkage, the design of these relief grooves is disadvantageously complex and always a compromise.

[0011] Axial piston pumps with their own housing are also known. In these designs, a connection between the high-pressure side and the bearing gaps between the rocker arm and the rocker arm bearing can also be established via bores in the housing.

[0012] However, this design requires multiple holes and plugs in the housing, which is a disadvantage. The result is a high manufacturing effort for the housing and critical manufacturing processes due to the long and small holes. This leads to increased production costs.

[0013] For known highly integrated axial piston pumps, which, for example, have a common housing with an electric motor, this solution is not feasible due to the space requirements and the arrangement of the parts.

[0014] Against this background, the present invention aims to improve a prior art axial piston pump mentioned above, particularly with regard to the bearing of the pivoting cradle.

[0015] This problem is solved by the subject matter with the features of independent claim 1. Advantageous embodiments of the invention are the subject of the dependent claims.

[0016] According to the invention, it is provided that the channel runs at least partially through the pivot bearing.

[0017] The axial piston pump can pump hydraulic fluid from a low-pressure side of the axial piston pump to a high-pressure side of the axial piston pump.

[0018] The swivel cradle is preferably hydrostatically supported or mountable in the swivel cradle bearing.

[0019] The pivoting cradle preferably has no connection to the bearing gap with the high-pressure side via the pivoting cradle. The channel preferably does not run through the pivoting cradle.

[0020] Preferably, the pivoting cradle is relieved hydrostatically. The pivoting cradle preferably has one or more relief grooves adjacent to the bearing gap.

[0021] The axial piston pump preferably has pistons with sliding shoes that are arranged on a surface of the pivoting cradle and can slide on this surface. The sliding shoes are preferably hydrostatically mounted or mountable on the surface, with the medium for this hydrostatic mounting not being supplied via the channel.

[0022] The hydrostatic bearings of the sliding shoes and the hydrostatic bearings of the pivoting cradle are preferably independent of each other, i.e., separate. This separation allows the respective relief grooves of the sliding shoes and the pivoting cradle to be optimized independently of each other.

[0023] There can also be several, e.g. two, bearing slots, each of which can be supplied with the medium via the channel.

[0024] Within the scope of the invention, the term "bearing gap" is preferably to be interpreted broadly and can also refer to several, in particular two, bearing gaps of a bearing arrangement.

[0025] Preferably, the channel comprises a pipe and / or one or more conduits, which are formed in particular by bores, in the pivot bearing.

[0026] Preferably, a direct connection is provided between an outlet on the high-pressure side of the axial piston pump and the slewing rocker bearing or the bearing gap between the slewing rocker and the slewing rocker bearing by means of the pipe. The hydraulic fluid can be supplied to the bearing gap or the bearing points via lines in the form of bores in the slewing rocker bearing.

[0027] The medium is preferably hydraulic fluid or hydraulic oil.

[0028] Preferably, hydraulic fluid is supplied via the pipe.

[0029] Preferably, one or more of the lines and / or the ends of the lines that are not arranged at the bearing gap are closed with a plug, in particular an expansion plug.

[0030] Preferably, the pipe should run straight.

[0031] Preferably, the pipe has one or more seals, in particular an O-ring or an O-ring, and also one or more support rings at one end or at both ends.

[0032] Preferably, the pipe is connected to the pivot bearing, in particular by being inserted into one of the lines.

[0033] Preferably, the axial piston pump includes an electric motor and / or can be driven by an electric motor.

[0034] The invention also relates to an arrangement with an axial piston pump according to the invention and a component, wherein the axial piston pump is arranged on the component, wherein the channel begins in the component and / or runs through the component.

[0035] The channel can be at least partially part of the axial piston pump and / or the component.

[0036] Preferably, the pipe is connected to the component, in particular inserted into a high-pressure channel of the component.

[0037] The invention also relates to an aircraft, in particular an airplane, with an axial piston pump and / or an arrangement according to the invention.

[0038] The axial piston pump is preferably an axial piston pump with an integrated electric motor for aviation applications, e.g. for extending and retracting landing gear or for a drive for a flight control system, etc.

[0039] Preferably, the invention reduces the manufacturing costs of an axial piston pump according to the invention compared to an axial piston pump according to the prior art, and preferably increases the process reliability in the manufacture of an axial piston pump according to the invention compared to the process reliability in the manufacture of an axial piston pump according to the prior art. Preferably, fewer seals and expansion plugs are required for an axial piston pump according to the invention than for an axial piston pump according to the prior art, which preferably increases the robustness and reliability of an axial piston pump according to the invention.

[0040] It should be noted here that the terms "a" and "an" do not necessarily refer to exactly one of the elements, although this is a possible interpretation, but can also denote a plurality of elements. Likewise, the use of the plural also includes the presence of the element in question in the singular, and conversely, the singular also includes several of the elements in question. Furthermore, all features of the invention described herein can be combined with one another or claimed separately from one another as desired.

[0041] Further advantages, features, and effects of the present invention will become apparent from the following description of preferred embodiments with reference to the figures, in which identical or similar components are designated by the same reference numerals. These figures show: Fig. 1: a sectional view of an embodiment of an axial piston pump according to the invention. Fig. 2: A sectional view of a prior art axial piston pump.

[0042] The in Fig. Figure 1 shows an axial piston pump with a pivoting cradle 2 mounted in a pivoting bearing 1 of the axial piston pump. The pivoting bearing 1 has two bearing shells 1a. Between the bearing shells 1a and the pivoting cradle 2, there is a bearing gap 3 for the hydrostatic mounting of the pivoting cradle 2.

[0043] Each bearing gap 3 is connected via a channel to an outlet located on the high-pressure side of the axial piston pump.

[0044] The channel comprises a conduit formed by several bores 5 in the pivot bearing 1 and a pipe 4. The bearing shells 1a also have bores that form part of the channel.

[0045] The bores 5 can be designed in any way and can also be offset, as shown in the illustration. Fig.1 emerges.

[0046] The axial piston pump is arranged on a component in the form of a connection plate 7.

[0047] The connection plate 7 has a high-pressure channel 7a connected to the outlet on the high-pressure side of the axial piston pump.

[0048] Pipe 4 is connected to high-pressure channel 7a by being inserted into the high-pressure channel. Pipe 4 is also connected to bores 5 by being inserted into bore 5.

[0049] Pipe 4 can also be connected to high-pressure channel 7a and / or borehole 5 in a different way. For example, the pipe can be screwed together.

[0050] The pipe 4 has a seal at each of its two ends in the form of an O-ring or an O-ring in combination with one or two support rings, which ensures a tight connection between the pipe 4 and the high-pressure channel 7a and the pipe 4 and the bore 5, even at high pressures, especially up to approx. 345 bar, of the hydraulic fluid flowing through the pipe, when the pipe is inserted into the high-pressure channel 7a and the bore 5 and the connecting plate 7 and the swivel bearing 1 are pressed together, e.g. by a screw connection.

[0051] Hydraulic fluid is supplied to the bearing gaps 3 via the outlet of the axial piston pump located on the high-pressure side.

[0052] In operation of the axial piston pump, the hydraulic fluid can therefore flow from the outlet on the high-pressure side of the axial piston pump via the high-pressure channel 7a in the connection plate 7, the pipe 4, the bores 5 and the bores in the bearing shells 1a into the bearing gaps 3, thereby building up pressure in the bearing gaps 3 and hydrostatically mounting the swivel cradle 2 in the swivel cradle bearing 1.

[0053] The swivel cradle 2 has a relief groove adjacent to each of the two bearing shells 1a, i.e. two relief grooves.

[0054] Tube 4 can also be called the transfer tube.

[0055] The pipe 4 is a standard hydraulic pipe and connects a high-pressure channel 7a of the connection plate 7 to the slewing cradle bearing 1. In the slewing cradle bearing 1, various bores 5 are arranged so that the hydraulic fluid enters the respective bearing gap between the two bearing shells 1a and the two relief grooves or pockets of the slewing cradle 2.

[0056] The bores 5 are closed towards the housing space of the axial piston pump with expansion plugs 6.

Claims

[1] Axial piston pump, in particular for an aircraft, comprising a pivot bearing and a pivot cradle, wherein the pivot cradle is mounted in the pivot bearing, wherein a bearing gap is provided between the pivot bearing and the pivot cradle, wherein a channel is provided through which a medium, in particular hydraulic fluid, can flow from an outlet located on the high-pressure side of the axial piston pump to the bearing gap, characterized by that the channel runs at least partially through the pivot bearing. [2] Axial piston pump according to claim 1, characterized by , that the channel includes a pipe and / or one or more conduits, which are formed in particular by bores, in the pivot bearing. [3] Axial piston pump according to claim 2, characterized bythat one or more of the lines and / or the ends of the lines that are not located at the bearing gap are closed with a plug, in particular an expansion plug. [4] Axial piston pump according to one of claims 2 to 3, characterized by that the pipe runs straight. [5] Axial piston pump according to any one of claims 2 to 4, characterized by that the pipe has one or more seals at one end or at both ends, in particular an O-ring or an O-ring and one or two support rings. [6] Axial piston pump according to any one of claims 2 to 5, characterized by that the pipe is connected to the pivot bearing, in particular inserted into one of the lines. [7] Axial piston pump according to one of the preceding claims, characterized by that the axial piston pump includes an electric motor and / or can be driven by an electric motor. [8] Arrangement comprising an axial piston pump according to one of the preceding claims and a component, wherein the axial piston pump is arranged on the component, characterized by that the channel begins in the component and / or runs through the component. [9] Arrangement according to claim 8, characterized by that the axial piston pump is designed according to one of claims 2 to 7 and that the pipe is connected to the component, in particular inserted into a high-pressure channel of the component. [10] Aircraft, in particular airplane, with an axial piston pump according to any one of claims 1 to 7 and / or with an arrangement according to any one of claims 8 or 9.

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