oil pump

Abstract

The invention relates to an oil pump (2) for a machine (1), in particular a fluid machine (1), preferably a compressor (1) or a piston compressor (1), for household, transport or industry use, with a pump piston (20) movable back and forth in a pump cylinder (30) for drawing in and expelling oil in an oil circuit (4) of the machine (1), wherein the pump piston (20) is mechanically coupled to a movable section (120) of the machine (1), and the pump piston (20) has a damping element (35) on its drive side (21) for damping a stroke, in particular a stroke height and / or a stroke frequency, of the oil pump (2).

Description

[0001] The invention relates to an oil pump for a machine and to a machine, in particular a fluid machine. State of the art

[0002] A compressor is a fluid machine used to compress a fluid such as air, a refrigerant, or another gas (mixture). The compressor receives energy from a power source such as an electric motor or a turbine. Compressors, especially reciprocating compressors, are commonly used in homes, transportation, and industry, for example, in air conditioning systems, refrigeration units (such as air conditioners or refrigerators), heat pumps, compressed air systems, etc.

[0003] For example, in a piston compressor, its piston is mounted within a compressor cylinder, driven by, for example, an electric linear motor, and moved back and forth within a hermetically sealed housing. This movement draws in, compresses, and expels a fluid. An oil film in the gap between the compressor piston and the compressor cylinder is necessary for lubrication, sealing, and / or cooling. Oil pumps, such as reciprocating or rotary pumps, are used for this purpose.

[0004] This means that an oil pump is provided to pump the oil, which is stored primarily in an oil sump within the piston compressor housing, into a gap between the compressor cylinder and the compressor piston, in order to ensure the lubrication, sealing, and / or cooling of the piston compressor. The power consumption of the oil pump results from the combination of its delivery rate and the pressure differential across the oil pump. For efficiency reasons, the power consumption of the oil pump should be low. Task

[0005] In known reciprocating oil pumps for compressors, their delivery rates are directly linked to the stroke of a movable section of the compressor. The delivery rate of such an oil pump depends on the diameter of its pump piston, which can only be reduced to a certain size; the stroke frequency of the oil pump, which is determined by its mechanically fixed connection to the overall compressor; and its stroke length, which is predetermined by the compressor design. This significantly limits any reduction in the delivery volume of a reciprocating oil pump. It is an object of the invention to provide an improved oil pump for a machine, e.g., a compressor. Disclosure of the invention

[0006] The object of the invention is achieved by means of an oil pump for a machine, in particular a fluid machine, preferably a compressor or a piston compressor, for household, transport or industrial use, and by means of a machine, in particular a fluid machine, preferably a compressor or a piston compressor, for household, transport or industrial use. Advantageous further developments, additional features and / or advantages of the invention will become apparent from the dependent claims and the following description.

[0007] The oil pump according to the invention comprises a pump piston movable back and forth in a pump cylinder for drawing in and expelling oil in an oil circuit of the machine, wherein the pump piston is mechanically coupled to a movable section of the machine, and the pump piston has a damping element on its drive side for damping a stroke, in particular a stroke height and / or a stroke frequency, of the oil pump. The oil circuit of the machine can, for example, serve for lubrication, sealing, and / or cooling of the machine. The movable section of the machine can, for example, be designed as a reciprocating, oscillating, vibrating, and / or damping section of the machine.

[0008] By means of the damping element according to the invention, a stroke (stroke height, stroke frequency, stroke profile, etc.) of the oil pump piston can be decoupled to a certain degree from a movement of the movable section of the machine, e.g., also a stroke or a portion of a movement of the movable section of the machine that can be interpreted as a stroke. The damping element creates a "reduction," whereby, in particular, the stroke height and / or stroke frequency of the pump piston is at least on average smaller than the stroke height and / or stroke frequency of the movable section of the machine.

[0009] The damping element can be mounted on the drive side of the pump piston, on the oil pump side. In this case, the damping element can either rest loosely against the pump piston, possibly with a positive fit, or be rigidly connected to the pump piston. In the latter case, the damping element can be materially bonded, frictionally bonded, and / or positively bonded to the pump piston. Here, an axial mounting pin of the pump piston can be incorporated into the damping element, or the damping element can mechanically engage with the pump piston.

[0010] The damping element can be mounted on the moving part of the machine. For this purpose, the damping element can be loosely and preferably at least partially positively engaged with the moving part of the machine, or it can be rigidly connected to the moving part of the machine. In the latter case, the damping element can be connected to the moving part of the machine by a material bond, a force bond, and / or a positive bond. An axial mounting pin of the moving part of the machine can be axially inserted into the damping element, or the damping element can be designed to engage with the moving part of the machine, for which the moving part of the machine is, of course, appropriately designed.

[0011] The damping element can be designed as an elastic element, in particular a spring, preferably a helical spring, or as an elastomeric element. The damping element can be centered within the pump cylinder, at least partially, and in particular with a longitudinal end section. Furthermore, the damping element can be guided linearly through the pump cylinder in sections. Additionally, the damping element can project from the pump cylinder with a longitudinal end section and be mechanically coupled to the movable section of the machine at its end.

[0012] The pump cylinder and the pump piston form a reciprocating piston pump of the oil pump, whose cylinder chamber serves for the intake and discharge of oil into the machine's oil circuit. The cylinder chamber can be positioned opposite the damping element in the reciprocating piston pump with respect to the pump piston. Furthermore, a return element for the pump piston, preferably designed as an elastic element, can be provided in the cylinder chamber. The return element can be mechanically supported at one longitudinal end against the pump piston and at its other longitudinal end against a cylinder base of the pump cylinder. Alternatively, an annular inner collar can be provided in the cylinder chamber for the latter purpose. The return element can be designed as a spring, preferably a helical spring, or as an elastomeric element.

[0013] The reciprocating piston pump can have an elastic element-mass oscillator or a spring-mass oscillator, wherein the pump piston is arranged to be movable back and forth between the two elastic elements or between the two springs. One of the elastic elements or one of the springs can serve to support the pump piston against a fixed side, in particular a stationary section within the machine, and a reciprocating movement can be imposed on the pump piston by means of the other elastic element or spring.

[0014] The oil pump can have an oil reservoir that is separate from the reciprocating pump or essentially separate from it. In this case, the oil reservoir may not be identical to the pump cylinder or the cylinder chamber of the reciprocating pump, which is characterized, for example, by the fact that the oil reservoir is not open to oil flow in the same main direction as the pump cylinder.

[0015] The cylinder chamber can be in fluid communication with a reservoir chamber of the oil reservoir, whereby oil pressure can be applied to the reservoir chamber via the cylinder chamber, and oil can be drawn in and / or expelled via the reservoir chamber. In this configuration, the cylinder chamber serves for indirect intake, and possibly direct compression and / or indirect expulsion of oil into the oil circuit, whereas the reservoir chamber serves for direct intake, possibly indirect compression and / or direct expulsion of oil into the oil circuit. The oil pump thus flows along its reservoir chamber.

[0016] The cylinder chamber can be configured as a primary pumping chamber in the reciprocating pump, whose volume can be varied by the pump piston and cylinder. The reservoir chamber, separate from the reciprocating pump, can be configured as a secondary pumping chamber in the oil pump, with a volume that is essentially constant.

[0017] The pump piston is, of course, designed as a movable pump piston, and the pump cylinder is, of course, designed as a stationary pump cylinder of the oil pump. Here, "movable" means that the pump piston can move within the machine and the oil pump, whereas "stationary" means that the pump cylinder is relatively immobile or at rest within the machine. In the latter case, the pump cylinder can be directly or indirectly rigidly connected to a housing and / or another potentially load-bearing structure of the machine. Furthermore, the oil reservoir can be rigidly connected to a stationary section of the machine.

[0018] In the oil circuit at the cylinder or reservoir, an inlet valve for the oil pump, particularly designed as an inlet check valve, may be provided upstream. Similarly, an outlet valve for the oil pump, particularly designed as an outlet check valve, may be provided downstream in the oil circuit at the cylinder or reservoir. The inlet valve and / or the outlet valve may, of course, also be electrically actuated or electrically controlled. The inlet check valve and the outlet check valve may be mechanically biased against the direction of oil flow through the cylinder or reservoir.

[0019] The cylinder chamber and the reservoir chamber can have essentially direct fluid communication, either unthrottled or throttled. The cylinder chamber can open essentially directly into the reservoir chamber, or an oil line can be installed between the cylinder chamber and the reservoir chamber. In the first case, the cylinder chamber shares a common wall, e.g., at the front, and the reservoir chamber shares a common wall, e.g., laterally. The cylinder chamber or the oil line can open into the reservoir chamber between the inlet valve and the outlet valve.

[0020] The cylinder chamber and the reservoir chamber can be arranged separately from each other in the oil pump such that a delivery direction of the cylinder chamber and a delivery direction of the reservoir chamber preferably have an angle other than 0° and 180° (naturally integer multiples thereof). The delivery direction of the cylinder chamber and a delivery direction of the reservoir chamber can each include an angle of approximately: 5°, 15°, 30°, 45°, 60°, 75°, 90° ±10°. However, an angle of 0° or 180° is also applicable, with the reservoir chamber being arranged, for example, parallel to the cylinder chamber. Furthermore, the ratio of the oil reservoir volume to the delivery volume of the piston pump can be approximately: 10; 9; 8; 7; 6; 5; 4; 3; 2; 1; 0.9; 0.8; 0.7; 0.6; 0.5; 0.4; 0.3; 0.2; 0.1 each ±10-25%.

[0021] When pumping oil using a piston pump, oil can be pumped into and out of the return spring. The reservoir can be straight, curved, or angled. It can also be a section, possibly widened, within an oil line of the machine. In such a case, it is easy to install the inlet and outlet valves. Of course, the oil reservoir can also be designed differently, such as a small tank or similar structure. Furthermore, the pump piston preferably does not have a through-hole for oil delivery by the oil pump.

[0022] The machine according to the invention has an oil sump or other oil reservoir from which oil can be pumped into an oil circuit of the machine by means of an oil pump, the oil pump being designed according to the invention. A control unit for controlling and / or regulating the operation of the machine may be included. The oil reservoir of the oil pump can be integrated into the oil circuit of the machine, while the piston pump of the oil pump is connected to the oil circuit of the machine. The oil reservoir is integrated into the oil circuit such that the inlet valve of the oil reservoir is located upstream and the outlet valve of the oil reservoir is located downstream.

[0023] During operation of the machine, the oil reservoir of the oil pump is essentially open to oil flow in only one direction. Depending on the volume of the oil reservoir and the frequency of the reciprocating pump, the oil flow through the reservoir is intermittent, essentially in the same direction (go-and-stop). During operation of the machine, oil can flow into the pump cylinder of the reciprocating pump in one direction and out in the opposite direction. Depending on the stroke of the reciprocating pump, a volume of oil flows in and then out again per cycle of the pump (in-and-out), with a different volume of oil flowing in and out in the following cycle.

[0024] The damping element of the reciprocating pump is mechanically coupled to a movable section of the machine. This section can be designed as a reciprocating, oscillating, vibrating, or damping section, etc. The pump cylinder can be rigidly connected to a stationary section of the machine. The oil reservoir can also be rigidly connected to a stationary section of the machine.

[0025] An upstream section of the reservoir in the oil circuit can be connected to the oil sump or another oil reservoir in the machine's oil circuit via the inlet valve. Furthermore, a downstream section of the reservoir in the oil circuit can be connected to a section of the machine via the outlet valve. This section can be a part of the machine requiring lubrication, sealing, and / or cooling. The pump cylinder of the reciprocating pump can be directly connected to the oil circuit between the inlet and outlet valves. In this case, an oil line from the inlet valve and / or a line leading to the outlet valve opens directly into the cylinder chamber of the pump cylinder.

[0026] In some embodiments, the reciprocating pump or the oil pump can be designed as a bearing and / or a damper within the machine. Furthermore, the oil pump can be located at least partially or substantially entirely within the oil sump or other oil reservoir. In addition, the machine can be used to operate an open or closed fluid circuit. Brief description of the character

[0027] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying schematic drawing, which is not to scale. In the invention, a feature can be positive (i.e., present) or negative (i.e., absent). In this specification, a negative feature is not explicitly defined as a feature unless the invention specifically emphasizes its absence. That is, the actual invention, rather than one constructed by the prior art, consists of omitting this feature. The absence of a feature (negative feature) in an exemplary embodiment indicates that the feature may be optional (to a person skilled in the art). The merely exemplary and highly schematic figure (Fig.) of the drawing shows an oil pump of a machine, in particular a fluid machine, with a reciprocating piston pump whose cylinder chamber is in fluid communication with an externally designed reservoir chamber of an oil reservoir of the oil pump. Embodiments of the invention

[0028] The invention – an oil pump 2 for a machine 1 – is explained in more detail below with reference to exemplary embodiments of an embodiment shown in the figure. The oil pump 2, or the machine 1 with the oil pump 2, can be used, for example, in an air conditioner, a refrigeration unit (e.g., an air conditioning unit or a refrigerator), a heat pump, a compressed air device, etc., for household, transportation, and / or industrial use; alternatively, the machine 1 can be configured as such. In principle, the invention is applicable wherever a machine 1 requires lubrication, sealing, and / or cooling, etc., by means of or through an oil.

[0029] The drawing shows only those sections of oil pump 2 and machine 1 that are necessary for understanding the invention. Although the invention is described and illustrated in detail by preferred embodiments, the invention is not limited by the disclosed embodiments. Other variations can be derived from them without departing from the scope of protection of the invention.

[0030] The figure shows a highly abstract embodiment of the oil pump 2 in a state installed in the machine 1, wherein the oil pump 2 can pump oil from an oil sump 100 of the machine 1 into a section of the machine 1 within an oil circuit 4 of the machine 1, in which there is a need for lubrication, sealing and / or cooling, etc., within the machine 1. An alternative to the oil sump 100 is another oil storage medium, e.g., in the form of an oil tank, a pan, etc., within the machine 1.

[0031] The oil pump 2 is positioned between an internally movable section 120 of machine 1 and an internally stationary section 140 of machine 1. The movable section 120 can be configured as a reciprocating, oscillating, vibrating, or damping section of machine 1. The stationary section 140 can, for example, be a section of a housing of machine 1 or a section rigidly connected to a housing of machine 1. Furthermore, the stationary section 140 can also be configured as an external stationary section (140). In this case, the oil pump 2 is positioned between the external section (140) and the machine 1 itself.

[0032] The oil pump 2 comprises a reciprocating pump 20, 30 and preferably (alternative see below) a separately designed oil reservoir 40, wherein the oil reservoir 40 is not substantially identical to a pump cylinder 30 of the reciprocating pump 20, 30. The oil reservoir 40 can be in fluid communication with the reciprocating pump 20, 30 substantially directly or indirectly, with the pump cylinder 30 opening substantially directly into the oil reservoir 40 or vice versa (not shown), or an oil line 53 can be provided between the oil reservoir 40 and the pump cylinder 30. In the alternative, the oil reservoir 40 is omitted, with the function of a reservoir chamber 43 of the oil reservoir 40 being taken over by a cylinder chamber 33 of the pump cylinder 30.

[0033] Depending on the distance between the pump cylinder 30 and the oil reservoir 40, the oil line 53 is of varying length. In a short version, it can be designed as a kind of nozzle 53 (see the figure), and in a longer version as a rigid or flexible line 53 (not shown), through which the oil reservoir 40 and the pump cylinder 30 are in fluid communication.

[0034] Furthermore, the pump cylinder 30 can be in direct fluid communication with the oil reservoir 40 at its end (not shown, but analogous to the figure, where the two oil delivery openings of the oil line 53 essentially coincide) or laterally (not shown). If the oil reservoir 40 is designed as an oil line 40, the pump cylinder 30 and the oil reservoir 40 in these cases have a more or less pronounced T- to L-shape, with the common joint preferably having no constriction (see figure) or thickening.

[0035] Furthermore, it is possible to split the oil reservoir 40 into two sections. In this case, an upstream section of the oil reservoir 40, relative to the pump cylinder 30, can be positioned at its front or side in essentially direct fluid communication with the pump cylinder 30. Similarly, a downstream section of the oil reservoir 40, relative to the pump cylinder 30, can also be positioned at its front or side in essentially direct fluid communication with the pump cylinder 30.

[0036] The pump cylinder 30 and the oil reservoir 40, in particular a major extension of each of these two, preferably enclose an angle α that deviates from 0° or 180° (and, of course, integer multiples thereof). A preferred angle α between a longitudinal extension of the pump cylinder 30 and a longitudinal extension of the oil reservoir 40 is approximately ±45° to approximately 90°, with an angle of approximately 90° being practical, depending, of course, on the application in the machine 1. Other angles α between the pump cylinder 30 and the oil reservoir 40 are, of course, applicable, see above.

[0037] The oil reservoir 40 serves for the direct intake and / or direct discharge of oil by the oil pump 2 into the oil circuit 4, whereby the variable oil pressure p does not originate from the oil reservoir 40, but rather from the reciprocating pump 20, 30, which is in fluid communication with the oil reservoir 40; more precisely, from the cylinder chamber 33 of the pump cylinder 30, the volume of which is variable by means of a pump piston 20. For this purpose, the pump piston 20 is arranged to be movable back and forth within the oil pump 2. That is, the reciprocating pump 20, 30 draws oil into the oil circuit 4 via the oil reservoir 40 and / or discharges oil into the oil circuit 4 via the oil reservoir 40.

[0038] The oil reservoir 40 is located in oil circuit 4 and forms a section of oil circuit 4 through which the oil flows essentially in one direction. Furthermore, the reciprocating pump 20, 30 is located in the area of ​​oil reservoir 4 in oil circuit 4 and does not form a section of oil circuit 4 through which the oil flows essentially in one direction, but rather forms a dead-end-like area (pump cylinder 30) for the oil in oil circuit 4, allowing inflow and outflow. With a split oil reservoir 40, depending on the design of the oil pump 2, the pump cylinder 30 may be open to radial flow. Alternatively, the oil from oil circuit 4 (without passing through oil reservoir 40) can flow directly into cylinder chamber 33 and / or flow directly out of cylinder chamber 33 into oil circuit 4 (without passing through oil reservoir 40).

[0039] The reciprocating pump 20, 30 comprises the pump piston 20 and the pump cylinder 30. The pump piston 20, which is particularly reciprocating, is mechanically coupled to the internally movable section 120 via its drive end 21 and a damping element 35. The pump cylinder 30, which is particularly stationary, is mechanically fixed to the internally stationary section 140. The optional oil reservoir 40 is also internally stationary.

[0040] The pump piston 20 has a delivery side 22 within the pump cylinder 30, located in its volume-variable cylinder chamber 33 (first delivery chamber 33). A return element 34, preferably designed as an elastic element 34, is accommodated within the cylinder chamber 33. This return element 34 rests against the delivery side 22 of the pump piston 20 on one side and against a cylinder base 31 inside the cylinder chamber 33 on the other. The elastic element 34 can be designed, for example, as a spring, a helical spring 34, or an elastomeric element, etc. Alternatively, the return element 34 can be supported within the cylinder chamber 33 by an inner, at least partially circumferential collar.

[0041] The cylinder base 31 has an oil delivery port leading to the oil reservoir 40. Alternatively, a cylinder wall can have the oil delivery port leading to the oil reservoir 40 (not shown). The oil delivery port leads to an oil delivery port in the oil reservoir 40, and an oil line 53 of varying length can be located between the two oil delivery ports. In a shorter configuration, the distance between the oil delivery port of the pump cylinder 30 and the oil delivery port of the oil reservoir 40 is approximately one wall thickness of the oil reservoir 40 and / or the pump cylinder 30. In the alternative configuration, at least one oil delivery port is missing because the oil circuit 4 can be connected directly to the pump cylinder 30 at least on one side.

[0042] The outer cross-section of the pump piston 20 and the inner cross-section of the pump cylinder 30 are essentially congruent, with the inner cross-section of the pump cylinder 30 being slightly larger than the outer cross-section of the pump piston 20. The cross-sectional shape is, in principle, arbitrary, but a circular shape is preferred. However, any elliptical, square, rectangular, or, in particular, regularly shaped polygonal cross-section is also suitable.

[0043] The shape of the oil reservoir 40 is, in principle, arbitrary and can, for example, be that of a pipe, a shape 40 adapted to the machine 1, a (small) tank 40, etc. In the figure, the oil reservoir 40 is shown as a hydraulic pipe. The oil reservoir 40, or in particular a reservoir chamber 43 of constant volume (second pumping chamber 43) of the oil reservoir 40, is fluid-mechanically a section in the oil circuit 4.

[0044] The oil reservoir 40 can be intermittently connected to the oil circuit 4 via an inlet valve 41 and an outlet valve 44, depending on the pumping frequency of the reciprocating pump 20, 30. The inlet valve 41 is specifically designed as an inlet check valve 41, and the outlet valve 44 is specifically designed as an outlet check valve 44. It is of course possible to install other valves 41, 44 in the oil pump 2 instead of check valves 41, 44, e.g., electrically controlled and / or regulated valves 41, 44.

[0045] The inlet check valve 41 and the outlet check valve 44 are preferably mechanically biased in the same direction, i.e., opposite to the direction of fluid flow through the reservoir chamber 43. The direction of fluid flow through the reservoir chamber 43 need not be straight; that is, the direction of fluid flow can be geometrically curved or angled, depending on the shape of the oil reservoir 40, and yet still be mechanically biased in the same direction with respect to the direction of fluid flow through the reservoir chamber 43.

[0046] The inlet valve 41 or the inlet check valve 41 is characterized in that it is provided upstream or immediately upstream of the reservoir chamber 43, or, in alternative embodiments, upstream or immediately upstream of the cylinder chamber 33. In both of the latter cases, the inlet valve 41 or the inlet check valve 41 can open / close directly at the reservoir chamber 43 or directly at the cylinder chamber 33, respectively.

[0047] The outlet valve 44 or the outlet check valve 44 is characterized in that it is provided downstream or immediately downstream of the reservoir chamber 43, or, in alternative embodiments, downstream or immediately downstream of the cylinder chamber 33. In both of the latter cases, the outlet valve 44 or the outlet check valve 44 can open / close directly at the reservoir chamber 43 or directly at the cylinder chamber 33.

[0048] According to the invention, the pump piston 20 has a damping element 35 on its drive side 21, opposite its delivery side 22. The damping element 35 serves to dampen a stroke, in particular a stroke height and / or a stroke frequency, of the pump piston 20. The damping element 35 is arranged in the machine 1 between an actuating surface 121 of the internally movable section 120 and the drive side 21 of the pump piston 20, which is reciprocating within the oil pump and within the machine. The damping element 35 is in particular designed as an elastic element, which can be, for example, a spring, a helical spring 35, an elastomer element, etc.

[0049] The pump piston 20 of the reciprocating piston pump 20, 30 is thus arranged between the damping element 35, which is designed in particular as an elastic element 35 or a spring 35, and the return element 34, which is designed in particular as an elastic element 34 or a spring 34. In this arrangement, the pump piston 20, the elastic elements 34, 35, or the springs 34, 35 form an elastic element-mass oscillator 34, 20, 35 or a spring-mass oscillator 34, 20, 35 in the oil pump 2.

[0050] The damping element 35 can be connected to the actuating surface 121 of the movable section 120 by a material bond, a force bond, and / or a positive connection. Furthermore, the damping element 35 can be connected to the drive side 21 of the pump piston 20 by a material bond, a force bond, and / or a positive connection. Such a mechanical connection can be implemented as a loose connection or a fixed connection.

[0051] In particular, it is possible that, for example, a pin-shaped projection of the movable section 120 and / or the pump piston 20 is received or engages within a relevant longitudinal end section of the damping element 35 for mutual fastening. Additionally or alternatively, it is possible that the damping element 35 is received or engages with a relevant longitudinal end section in the movable section 120 and / or in the pump piston 20 for mutual fastening.

[0052] Starting from a stroke of the movable section 120, or a portion of a movement of the movable section 120 that constitutes a stroke, this stroke is transferred to the damping element 35. The damping element 35 dampens this stroke and transfers it via the drive side 21 of the pump piston 20 to the pump piston 20, which in this example is assumed to be at its top dead center.

[0053] The pump piston 20 moves into the cylinder chamber 33 due to the stroke damped by the damping element 35 and pumps oil from the reservoir chamber 43 or the cylinder chamber 33 (alternatively) into the oil circuit 4 of the machine 1. Naturally, the outlet valve 44 has opened or been opened in this process. This movement of the pump piston 20 can be dampened to a greater or lesser degree by the return element 34, with low or high damping being applicable depending on the application.

[0054] In the illustrated embodiment, it should be noted that the force by which oil is drawn in via the inlet valve 41 must originate from the restoring element 34, whereby the restoring element 34 must also overcome a counterforce from the steam element 35. Generally, with elastic elements 34 and 35, the restoring element 34 is designed to be stiffer than the damping element 35.

[0055] The open outlet valve 44 closes when the pump piston 20 has essentially reached its bottom dead center (bottom dead center). The pump piston 20 reverses its linear motion and is moved by the return element 34 back towards its top dead center (top dead center). At this point, the inlet valve 41 opens, allowing oil to be drawn into the reservoir chamber 43 or the cylinder chamber 33 (alternatively) by means of the pump piston 20. The movement of the pump piston 20 can be damped by the damping element 35, depending on the position of the movable section 120. The pump piston 20 then moves towards its top dead center (top dead center), and the cycle of the reciprocating pump 20,30 begins anew.

Claims

[1] Oil pump (2) for a machine (1), in particular a fluid machine (1), preferably a compressor (1) or a piston compressor (1), for household, transport or industry use, with a pump piston (20) movable back and forth in a pump cylinder (30) for drawing in and expelling oil in an oil circuit (4) of the machine (1), wherein the pump piston (20) is mechanically coupled to a movable section (120) of the machine (1), characterized by , that the pump piston (20) has a damping element (35) on its drive side (21) for damping a stroke, in particular a stroke height and / or a stroke frequency, of the oil pump (2). [2] Oil pump (2) according to the preceding claim, characterized by , that: • the damping element (35) is mounted on the oil pump side on the drive side (21) of the pump piston (20), • the damping element (35) can be stored on the machine side of the movable section (120) of the machine (1), and / or • the damping element (35) is designed as an elastic element (35), in particular as a spring (35), preferably a coil spring (35), or as an elastomer element (35). [3] Oil pump (2) according to one of the preceding claims, characterized by , that: • the damping element (35) is received at least section by section, in particular with a longitudinal end section, centrally within the pump cylinder (30), • the damping element (35) is guided linearly through the pump cylinder (30) section by section, and / or • the damping element (35) protrudes from the pump cylinder (30) with a longitudinal end section and can be mechanically coupled at its longitudinal end to the movable section (120) of the machine (1). [4] Oil pump (2) according to any one of the preceding claims, characterized by, that the pump cylinder (30) and the pump piston (20) form a reciprocating piston pump (20, 30) of the oil pump (2), whose cylinder chamber (33) serves to draw in and expel oil into the oil circuit (4) of the machine (1), wherein: • with respect to the pump piston (20) the cylinder chamber (33) is arranged opposite to the damping element (35) in the reciprocating piston pump (20, 30), • a return element (34), designed in particular as an elastic element (34), for the pump piston (20) is provided in the cylinder chamber (33), and / or • the return element (34) is designed as a spring (35), preferably a coil spring (35), or as an elastomer element (34). [5] Oil pump (2) according to any one of the preceding claims, characterized by, that the reciprocating piston pump (20, 30) has an elastic element mass oscillator (34, 20, 35) or a spring mass oscillator (34, 20, 35), wherein the pump piston (20) is arranged to be movable back and forth between the two elastic elements (34, 35) or between the two springs (34, 35), wherein one of the elastic elements (34) or one of the springs (34) serves to support the pump piston (20) on a stationary side, in particular a stationary section (140) within the machine, and a reciprocating movement can be imposed on the pump piston (20) by means of the other elastic element (35) or the other spring (35). [6] Oil pump (2) according to one of the preceding claims, characterized by , that: • the oil pump (2) has an oil reservoir (40) that is separated from or essentially separate from the reciprocating piston pump (20, 30), • the cylinder chamber (33) is in fluid communication with a reservoir chamber (43) of the oil reservoir (40), wherein an oil pressure (p) can be imposed on the reservoir chamber (43) by means of the cylinder chamber (33), and the oil can be drawn in and / or expelled by means of the reservoir chamber (43), and / or • the cylinder chamber (33) is set up as a first delivery chamber (33) in the reciprocating piston pump (20, 30) whose volume can be changed by the pump piston (20) and the pump cylinder (30), and the reservoir chamber (43) is set up away from the reciprocating piston pump (20, 30) as a second delivery chamber (43) in the oil pump (2) with an essentially constant volume. [7] Oil pump (2) according to one of the preceding claims, characterized by , that: • in the oil circuit (4) upstream at the cylinder chamber (33) or at the reservoir chamber (43), in particular an inlet valve (41) designed as an inlet check valve (41), • in the oil circuit (4) downstream at the cylinder chamber (33) or at the reservoir chamber (43) an outlet valve (44) is provided, in particular designed as an outlet check valve (44), and / or • the inlet check valve (41) and the outlet check valve (44) are mechanically biased against the direction of oil flow through the cylinder chamber (33) or the reservoir chamber (43). [8] Machine (1), in particular fluid machine (1), preferably compressor (1) or piston compressor (1), for household, transport or industry use, wherein the machine (1) has an oil sump (100) or other oil reservoir from which oil can be pumped into an oil circuit (4) of the machine (1) by means of an oil pump (2) of the machine (1), characterized by , that the oil pump (2) is designed according to one of the preceding claims. [9] Machine (1) according to the preceding claim, characterized by , that: • the oil reservoir (40) of the oil pump (2) is integrated into the oil circuit (4) of the machine (1), whereas the reciprocating piston pump (20, 30) of the oil pump (2) is connected to the oil circuit (4) of the machine (1), • in operation of the machine (1) the oil reservoir (40) of the oil pump (2) is accessible to oil flow in essentially one direction, and / or • in operation of the machine (1) oil can flow into the pump cylinder (30) of the reciprocating pump (20, 30) in one direction and flow out in the opposite direction. [10] Machine (1) according to any one of the preceding claims, characterized by , that: • the damping element (35) of the reciprocating pump (20, 30) is mechanically coupled to a movable section (120) of the machine (1), • the pump cylinder (30) is rigidly connected to a stationary section (140) of the machine (1), and / or • the oil reservoir (40) is rigidly connected to a stationary section (140) of the machine (1). [11] Machine (1) according to any one of the preceding claims, characterized by , that: • an upstream section of the reservoir space (43) in the oil circuit (4) can be brought into fluid communication with the oil sump (100) or the other oil storage reservoir in the oil circuit (4) of the machine (1) via the inlet valve (41), and / or • a downstream section of the reservoir space (43) in the oil circuit (4) can be brought into fluid communication with a section of the machine (1) via the outlet valve (44), or • is directly connected fluid-mechanically to the oil circuit (4) between the inlet valve (41) and the outlet valve (44) of the pump cylinders (30) of the reciprocating pump (20, 30). [12] Machine (1) according to any one of the preceding claims, characterized by , that: • the reciprocating piston pump (20, 30) or the oil pump (2) is designed as a bearing and / or a damper within the machine (1), • the oil pump (2) is installed at least partially or substantially entirely in the oil sump (100) or the other oil reservoir, and / or • an open fluid circuit or a closed fluid circuit can be operated by means of the machine (1).

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