Piston compressor valve arrangement and method of use

Abstract

A valve arrangement for a piston compressor, comprising an intake valve section (200) and a discharge valve section (300), the intake valve section (200) and the discharge valve section (300) together forming a working chamber head section (1200), and the intake valve section (200) having a truncated pyramidal shape.

Description

Detailed Description of the Invention

[0001] [Field] The present invention relates to a valve arrangement for a piston compressor. More specifically, the present invention relates to optimizing the flow areas in the suction and discharge valve sections of a piston compressor. While the present invention finds particular utility in the field of high temperature heat pumps, it may be used in piston compressors in any machine, not just high temperature heat pumps.

[0002] [background] Thermal machines, such as heat pumps, are known devices. Heat pumps are commonly used to heat indoor spaces or to provide hot water, steam, or hot air to users. The use of heat pumps is desirable because they provide more sustainable heat than heating devices that use fossil fuels or direct electrical heating (e.g., purely resistive heaters). Heat pumps transfer thermal energy from a low-temperature heat source to a high-temperature heat sink.

[0003] Many industrial processes require high temperature heat, e.g., in the form of steam or hot water, which are very energy intensive to produce, especially when primary energy sources are used. Examples of industries that utilize high temperature heat include pulp and paper, food and beverage, chemicals, automotive, metals, plastics, engineering, textiles, and wood. For example, in the food and beverage industry, high temperature heat is used in processes such as drying, evaporation, pasteurization, sterilization, boiling, distillation, blanching, stripping, condensing, tempering, and smoking, to name just a few.

[0004] Industrial waste heat is often unused due to its low temperature, which is lower than that required for many industrial processes. This waste heat can be upgraded and reused using high temperature thermal machines, such as high temperature heat pumps, which has clear economic and environmental benefits.

[0005] Heat pumps in both domestic and industrial settings are known technology. The operating principle of a heat pump is described in German patent application DE102011086476A1 by Siemens AG. This patent application advantageously describes the principle of a high temperature heat pump.

[0006] A heat pump typically includes an evaporator unit, a condenser unit, an expansion unit, and an electrically driven compressor for compressing a working fluid that circulates in a closed-loop working fluid circuit.

[0007] The working fluid is provided in a gaseous state from the evaporator unit to a compressor, which typically takes in the working fluid and compresses it to a suitable pressure so that, after compression of the gaseous working fluid in the compressor, the temperature of the working fluid is raised to a level that is usable by heat consumers.

[0008] The prior art utilizes various forms of compressors for this application, for example, screw compressors, vane compressors, rotary piston compressors, and reciprocating compressors have all been used in the prior art.

[0009] Reciprocating compressors are well known and well understood in many applications, not just in the field of heat pump technology. Reciprocating compressors are well suited to operating at temperatures above 100°C due to their construction being much like internal combustion engines, which are designed for temperatures up to several hundred degrees Celsius in the working chamber and lubricant temperatures up to approximately 100°C.

[0010] A reciprocating compressor has a basic operating principle of having a movable piston within a working chamber. The movable piston draws in a gaseous working fluid on its downstroke. The working fluid is drawn into the working chamber from the suction chamber through a suction valve section. The working fluid is compressed and then discharged into a discharge channel through a discharge valve section. This operation is very well understood by those skilled in the art and forms the very basic operating regime of well-known reciprocating compressors.

[0011] The piston in a piston compressor reciprocates on the longitudinal axis of the cylinder. In this regard, the piston moves up and down along the longitudinal axis of the cylinder to provide the reciprocating motion. In the context of this disclosure, the described compressor will be referred to as a piston compressor.

[0012] It will be appreciated that piston compressors, when used in heat pump systems, are most commonly combined with other components. For example, piston compressors are typically combined with a drive unit, which in most cases is an electric motor. Furthermore, piston compressors are typically also combined with a lubricant reservoir that continuously provides lubricant to the piston compressor during use. Lubricant is typically required to lubricate the pistons themselves and / or components of the piston compressor, such as bearings, cylinders, etc.

[0013] The most basic piston compressor design provides a working chamber with a flat working chamber head section, with the inlet and outlet valve sections located in the flat working chamber head section and perpendicular to the longitudinal axis of the cylinder, as will be described in more detail below.

[0014] Common to all compressor types is that they operate with a working fluid, also commonly referred to as a refrigerant or simply a gas. In some examples, the working fluid may be a condensable gas. In other examples, the working fluid never changes phase, and thus the working fluid is operated only in a gaseous state. In further examples, there is a combination of the two aforementioned modes. Throughout this disclosure, when referring to a working fluid, any working fluid in any phase, including but not limited to, partially liquid, gas, and supercritical, is intended.

[0015] The performance of a heat pump compressor, and more specifically a gas / vapor compressor, is primarily a result of three characteristics: 1. Mechanical efficiency 2.Volumetric efficiency 3. Isentropic efficiency Mechanical efficiency is primarily a result of internal mechanical friction, or rather the lack thereof. Volumetric efficiency is primarily a result of the internal so-called dead volume (also called the clearance volume in the working chamber of the compressor, i.e. the minimum achievable internal volume in the cylinder of the working chamber of the compressor during compression). Finally, isentropic efficiency is primarily a result of the effectiveness of the gas exchange processes, including the intake and exhaust processes.

[0016] Besides this, there are further factors that affect the aforementioned properties, such as heat leakage / undesired heat exchange through internal surfaces, e.g., cylinder walls, which affect isentropic efficiency, and gas leakage through sealing elements etc., which affect isentropic and volumetric efficiency.

[0017] Compressor operation consists of four main processes (or steps) that are performed cyclically: for piston compressors, these are performed once per revolution of the crankshaft (or other piston driving means, e.g., swash plate).

[0018] 1. Inhalation process. 2. Compression process. 3. Discharge process.

[0019] 4. Re-inflation process. The intake and discharge processes involve gas exchange processes during which working fluid, usually in gas / vapor form, is either drawn into or discharged from the cylinder. The gas exchange processes are governed by intake and discharge valves: the intake valve controls the flow of fresh, uncompressed gas into the cylinder during the intake process, while the discharge valve controls the flow of compressed gas out during the discharge process.

[0020] A compressor can have one or more cylinders, each with its corresponding set of suction and discharge valves, each of which can then, as is quite common, consist of multiple valves operating in parallel. Throughout this disclosure, for clarity and brevity, reference is made to a single cylinder (and corresponding piston, suction and discharge valve sections, etc.). It will be understood that any single cylinder may be a single cylinder within a system of multiple cylinders (and corresponding pistons, suction and discharge valve sections, etc.).

[0021] In conventional compressor designs, the suction / discharge valves are often in the form of so-called reed valves, which constitute a simple yet effective primary component for many compressor applications.

[0022] In principle, a reed valve comprises at least a valve plate or valve port section having a reed element (also called a reed valve blade) and a retainer (sometimes called a stop plate). The reed element is usually in the form of a thin metal sheet, sometimes also made from a spring material, which performs the actual opening and closing of the valve by covering or uncovering a port opening, slot, or the like in the valve plate or valve port section. A separate spring element may be provided, which is made to continuously press against the reed element and thus exert a force on it in the closing direction. This is to assist in closing the valve and to prevent flow through the valve when it would otherwise be closed. The retainer may typically be a curved, relatively rigid piece of sheet metal shaped to "curl" the lead element against its curved surface in order to limit movement of the lead element, thus guiding it and preventing damage that might otherwise occur from excessive bending during operation. Sometimes the retainer is in the form of a retainer plate that is fixed a certain distance from the lead element, often with a spring element between the retainer plate and the lead element. While the primary function is the same, designs can vary.

[0023] Reed valves are passively operated, meaning that they open or close solely due to a pressure differential (or lack thereof) across the reed element in the opening direction. Reed valves are small and lightweight, and their design is generally simple, making them easy and inexpensive to manufacture. However, reed valves have several drawbacks for certain applications. It is difficult to design a reed valve with an effective flow area comparable to that of certain other valve types, and it is also difficult to design a compressor with a very low dead volume, especially when the suction valve is of the reed type and a corresponding suction valve retainer (stop plate) is provided, since this subsequently results in the formation of some immovable dead volume. As a result, compressors equipped with reed valves usually have a higher dead volume and a smaller effective flow area than necessary. This in turn results in lower volumetric efficiency and lower isentropic efficiency, respectively.

[0024] One area in which improvement can be made in piston compressors is in the placement of the suction and discharge valve sections. Flow through these valve sections can be optimized in different ways. One such method is to increase the available area for each of the valve sections. This has been provided in prior art attempts to optimize performance. More specifically, attempts have been made to optimize performance by angling the suction and discharge valves away from a 90 degree orientation with respect to the cylinder axis.

[0025] That is, the valve section forms a wedge-shaped cross section at the head section, which provides the valve section with an increased surface area when compared to the flat head section previously described. Chinese utility model document CN201739117U describes an acetylene compressor that utilizes a wedge-shaped cross section.

[0026] Further optimizing the valve section layout to further improve piston compressor performance is difficult. Performance optimization is based on many different parameters, which are affected by changes to the head section design. While it is possible to significantly increase the surface area of ​​the suction and discharge valve sections, this typically results in a significant increase in dead volume. In this regard, it would be highly desirable to increase the suction and discharge valve areas without significantly increasing the dead volume, thereby resulting in an optimized piston compressor valve layout.

[0027] Additionally, the particular valve configurations used in the suction and discharge valve sections can have a significant impact on the performance of the piston compressor. For example, the particular valves used can increase the dead volume in the head section, thereby affecting the performance of the piston compressor.

[0028] Thus, piston compressors can be described as complex systems whereby optimizing performance depends on many interrelated components and design considerations. It would therefore be highly desirable to provide a valve arrangement for a piston compressor that results in optimization of the performance of the piston compressor, rather than simply optimizing one parameter at the expense of another.

[0029] Patent document SE354505B discloses a piston compressor and, in particular, the arrangement of a pressure valve in such a compressor. The compressor comprises a cylinder in which a piston moves up and down via the action of a crankshaft. The cylinder is provided with a valve plate. An intake duct is arranged on the side of the cylinder head and is covered by an expansion valve flap.

[0030] Patent document US231059A discloses a vertically positioned pump barrel or cylinder, the lower section of whose interior is made in the form of a truncated cone or pyramid whose lower end is closed, and which has a series of openings through its sloping sides, the openings being spaced around the periphery of the pump barrel or cylinder and each adapted to be covered by one or more valves arranged to rest on sloping valve seats within said pump barrel and to open inwardly.

[0031] Patent document US2004 / 163713A discloses an intake reed valve including a central ring-shaped body with a pair of radially outwardly extending tabs, one of which is fixed to a valve plate and the other tab is free-floating. A waisted region is located between the fixed tabs and the central ring-shaped body to facilitate bending / flexion of the intake reed valve.

[0032] Patent document US2015 / 0204323A1 discloses a compressor cylinder head having a cylinder head housing and at least one pressure valve. The pressure valve has an associated pressure valve channel within the cylinder head housing. The pressure valve channel connects a compression chamber disposed below the compressor cylinder head to a pressure chamber inside the compressor cylinder head. The compressor cylinder head further has one or more channel portions with a first coolant channel system inside the cylinder head housing, which can be filled with coolant that flows around the pressure chamber. The cylinder head housing is manufactured integrally with the first coolant channel system via a casting method, and additional coolant channels are disposed on either side of the at least one pressure valve channel.

[0033] It is at least one object of the present invention to obviate or at least mitigate one or more disadvantages of the prior art. [overview] According to a first aspect of the present invention, there is provided a valve arrangement for a piston compressor, the valve arrangement comprising an inlet valve section and a discharge valve section, the inlet valve section and the discharge valve section together forming a working chamber head section, the inlet valve section having a truncated pyramidal shape.

[0034] The intake valve section may include at least a first self-actuating check valve. The truncated pyramidal shape of the intake valve section may include a plurality of sides, and the first self-actuating check valve is located on a first of the plurality of sides of the intake valve section.

[0035] The first self-actuated check valve may comprise a first reed intake valve. The intake valve section may include at least a first intake port configured to provide fluid communication through the intake valve section, and the first reed intake valve includes at least a first finger blade positioned to open and close the first intake port.

[0036] The intake valve section may include a second intake port configured to provide fluid communication through the intake valve section, and the first finger blade is positioned to open and close the second intake port.

[0037] The intake valve section may include a second intake port configured to provide fluid communication through the intake valve section, and the first reed intake valve includes a second finger blade positioned to open and close the second intake port.

[0038] The first finger blade and the second finger blade may be integral. The first finger blade and the second finger blade may be non-integral. The valve arrangement may further comprise a first finger catch configured to prevent movement of the first finger blade.

[0039] The valve arrangement may further comprise a second finger catch configured to prevent movement of the second finger blade. The discharge valve section may include a first discharge port configured to provide fluid communication through the discharge valve section and to prevent movement of the first finger blade.

[0040] The discharge valve section may include a second discharge port configured to provide fluid communication through the discharge valve section and to prevent movement of the first finger blade and / or the second finger blade.

[0041] The valve arrangement may further include a second self-actuating check valve located on a second of the sides of the intake valve section. The second self-actuated check valve may comprise a second reed intake valve.

[0042] The intake valve section may include at least a third intake port configured to provide fluid communication through the intake valve section, and the second reed intake valve includes at least a third finger blade positioned to open and close the third intake port.

[0043] The intake valve section may include a fourth intake port configured to provide fluid communication through the intake valve section, and the third finger blade is positioned to open and close the fourth intake port.

[0044] The intake valve section may include a fourth intake port configured to provide fluid communication through the intake valve section, and the second reed intake valve includes a fourth finger blade positioned to open and close the fourth intake port.

[0045] The first finger blade and the second finger blade may be integral. The first finger blade and the second finger blade may be non-integral. The valve arrangement may have a central axis configured to be aligned with the longitudinal axis of the cylinder of the piston compressor in use, and the discharge valve section configured perpendicular to the central axis such that, in use, the discharge valve section is at 90 degrees, or substantially 90 degrees, to the longitudinal axis of the cylinder.

[0046] According to a second aspect of the present invention, there is provided a valve arrangement for a piston compressor, the valve arrangement comprising an inlet valve section and a discharge valve section, the inlet valve section and the discharge valve section together forming a working chamber head section, the inlet valve section having a substantially frusto-conical shape with at least a first flat side.

[0047] The intake valve section may include at least a first self-actuating check valve located on the first flat side. The first self-actuated check valve may comprise a first reed intake valve.

[0048] The intake valve section may include at least a first intake port configured to provide fluid communication through the intake valve section, and the first reed intake valve includes at least a first finger blade positioned to open and close the first intake port.

[0049] The valve arrangement may further comprise a first finger catch configured to prevent movement of the first finger blade. The discharge valve section may include a first discharge port configured to provide fluid communication through the discharge valve section and to prevent movement of the first finger blade.

[0050] The valve arrangement may have a central axis configured to be aligned with the longitudinal axis of the cylinder of the piston compressor in use, and the discharge valve section configured perpendicular to the central axis such that, in use, the discharge valve section is at 90 degrees, or substantially 90 degrees, to the longitudinal axis of the cylinder.

[0051] According to a third aspect of the present invention, there is provided a valve arrangement for a piston compressor, the valve arrangement comprising an inlet valve section and a discharge valve section, the inlet valve section and the discharge valve section together forming a working chamber head section, and the discharge valve section having a truncated pyramidal shape.

[0052] According to a fourth aspect of the present invention, there is provided a valve arrangement for a piston compressor, the valve arrangement comprising an inlet valve section and a discharge valve section, the inlet valve section and the discharge valve section together forming a working chamber head section, the discharge valve section having a substantially frusto-conical shape with at least a first flat side.

[0053] According to a fifth aspect of the present invention, there is provided a piston compressor comprising: a cylinder having a longitudinal axis; a piston mounted within the cylinder and linearly movable along the longitudinal axis; and a valve arrangement according to any of the first to fourth aspects of the present invention.

[0054] The piston may include a piston head section mated with the working chamber head section. According to a sixth aspect of the present invention, there is provided a method of optimizing fluid flow through a valve arrangement, the method comprising the steps of providing a valve arrangement according to any of the first to fourth aspects of the present invention, inhaling working fluid through an intake valve section, and discharging working fluid through a discharge valve section.

[0055] According to a seventh aspect of the present invention, there is provided a method of operating a piston compressor, the method comprising the steps of providing a piston compressor according to the fifth aspect of the present invention, drawing working fluid into a cylinder via an intake valve section, compressing the working fluid by moving a piston linearly along a longitudinal axis, and discharging the working fluid from the cylinder via a discharge valve section. [Brief explanation of the drawings]

[0056] Embodiments of the present invention will now be described with reference to the following drawings. [Figure 1] 1 shows a cross section through a prior art piston compressor. [Figure 2a-2b] FIG. 2a shows a computer-aided design model of a first modified working chamber having a first angled surface and a second angled surface, and FIG. 2b shows a computer-aided design model of a second modified working chamber having a first angled surface and a second angled surface and a third surface perpendicular to the cylinder axis. [Figure 2c] 10 shows a computer-aided design model of a third modified working chamber having a truncated tapered shape. [Figure 2d] 10 shows a computer-aided design model of a fourth modified working chamber having a truncated pyramidal shape. [Figure 3] FIG. 1 shows a cross section through a cylinder head with a valve arrangement of a piston compressor, with the intake valves not shown. [Figure 4] FIG. 4 shows the same cross section through the cylinder head shown in FIG. 3, with the intake valves shown. [Figures 3a-4a] FIG. 5 shows a cross-sectional view of the section shown in FIGS. 3 and 4, with the cylinder visible. [Figure 3b-3c] FIG. 5 shows a detailed view of the intake valve section shown in FIG. 4. [Figure 3d-3e] 1 shows a first alternative finger blade arrangement. [Figure 3f-3g] 10 shows a second alternative finger blade arrangement. [Figure 5] FIG. 4 shows a plan view of the cylinder head shown in FIG. 3. [Figure 6] FIG. 4 shows an isometric view of the cylinder head shown in FIG. [Figure 7] 1 shows a cross section through an alternative cylinder head. [Figure 8] 1 shows a cross section through a cylinder head of a multi-cylinder engine. [Figure 9] 9 shows an isometric view of the cylinder head of the multi-cylinder shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0057] It will be appreciated that for the sake of brevity and clarity, many of the basic components of a piston compressor are not shown in the drawings. Some of the basic components missing from the drawings are key components of a piston compressor, such as pistons and cylinders. It will be understood that these are missing from the drawings because the exact configuration of the missing components is not critical to the presently described invention of the valve arrangement.

[0058] [Detailed description of the drawings] Throughout this description, references are made to truncated pyramids, truncated pyramidal shapes, truncated pyramidal shapes, truncated cones, truncated conical shapes, truncated conical shapes, etc. In geometry, a pyramid is a polyhedron formed by connecting a polygonal base with points called vertices. Each base edge and vertex forms a triangle, called a side.

[0059] A regular pyramid has a regular polygonal base. An irregular pyramid has an irregular polygonal base. Pyramids with triangular bases are often called tetrahedrons. However, in this disclosure, pyramids with triangular bases are included under the general term pyramid, rather than being individually referred to as tetrahedrons. In this regard, pyramids, and additional pyramidal-derived shapes discussed herein, may have polygonal bases with three or more edges and three or more side surfaces. As discussed below, the number of side surfaces is not critical to the present invention.

[0060] Continuing with reference to geometric shapes in general, truncation is the operation of cutting the vertices of a hyperpolyhedron in any dimension, resulting in a new facet in place of each vertex. More simply stated, a truncated shape is a shape that has had one of its parts or corners cut off.

[0061] As previously mentioned, reference is made throughout this disclosure to truncated pyramids. The truncated pyramids described may have multiple sides so as to appear substantially like a truncated cone. As will be explained in more detail below, even if there are multiple sides making up the truncated pyramid, each side has a substantially flat surface, as will be explained below.

[0062] A cone is a geometric shape that tapers smoothly from a flat base to a point called the apex. Most commonly, the base of a cone is a perfect circle. However, the base need not be a perfect circle to create a cone in this context. In common usage, a cone is typically a right circular cone, with a circular base and the axis of the cone passing through the center of the base at a right angle to its plane. This can be contrasted with an oblique cone, where the axis of the cone passes through the center of the base non-perpendicularly. As previously mentioned, the base can be any shape, and the apex can be anywhere within the cone. As previously mentioned, a cone with a polygonal base is called a pyramid.

[0063] In geometry, a frustum is a three-dimensional geometric shape formed by the volume between two parallel planes and a polyhedron, often a pyramid or a cone. Thus, in geometry, a truncated cone shape is the same as a truncated cone shape, and a truncated pyramid shape is the same as a truncated pyramid shape.

[0064] It will be understood that the cones and pyramids may be solid or hollow. In this context, for the most part, reference is made to the valve section being frustoconical or frustopyramidal in shape. It will become apparent that the valve section in a piston compressor cannot be a solid pyramidal or conical in shape. Rather, as will be shown in the ensuing description and with reference to the figures, the valve section is a shell-like, hollow structure. The use of the prefix "frusto" to designate the primary shape may generally be considered as removing the requirement that the shape have an apex. In this regard, throughout this disclosure, frustoconical and frustopyramidal shapes generally refer to frustoconical and frustopyramidal shapes that are open at their truncated top and bottom portions, allowing the working fluid to flow through them.

[0065] Although it may often be convenient to provide a truncated cone or pyramid between two parallel planes, the terms truncated pyramid and frustum are not limited to truncated portions between two parallel planes, rather, it will be understood that a truncated portion may be formed between two non-parallel planes.

[0066] Additionally, a solid cone or pyramid would obstruct the aforementioned stroke of the piston within the cylinder at the head section of the cylinder. FIG. 1 illustrates a prior art compressor 1 in the form of a piston compressor utilizing a condensable working fluid. The compressor 1 includes a working chamber 2 and a reciprocating piston 3 disposed inside a cylinder 4. The working chamber 2 is defined by the piston 3, the cylinder 4, and a working chamber head section 5. The working chamber 2 is for compressing a compressible working fluid therein. As can be seen in FIG. 1, the working chamber head section 5 is formed by an inlet valve section 6 and a discharge valve section 7. The working chamber head section 5 is substantially planar. That is, the inlet valve section 6 and the discharge valve section 7 are arranged so as to share substantially the same plane and not be angled relative to one another, as can be clearly seen in FIG. 1. Continuing to refer to FIG. 1, the inlet valve section and the discharge valve section are disposed perpendicular to the longitudinal axis L of the cylinder 4. In such an arrangement, the available flow area through the inlet valve section and the discharge valve section is relatively small. As discussed above, a reduction in the available flow area has a detrimental effect on the overall performance of the compressor.

[0067] Referring now to Figures 2a and 2b, there are shown computer-aided design (CAD) models of the working chamber volume provided solely to assist in the description of the present invention, which will be described below. Figures 2a and 2b are labeled "Prior Art" because they are models based on known valve layout designs. These models are provided as a baseline, modified working chamber volume for the following description of flow through the top section of the working chamber.

[0068] Referring first to Figure 2a, a first working chamber volume 2a is provided. An intake valve section 6a and an exhaust valve section (not visible in Figure 2a) are also provided. The intake valve section 6a and the exhaust valve section are out of a 90 degree alignment with respect to the cylinder axis La, thereby resulting in a wedge-shaped cross section in the head section shown.

[0069] The exemplary first working chamber volume 2a has a diameter d2a of 210 mm, and the inlet valve section 6a and the outlet valve section span a longitudinal height l2a of 75 mm from the top of the head section. The available area for the inlet valve section 6a is approximately 210 cm 2 and the available area for the discharge valve section is approximately 210 cm 2 Therefore, the total available area for the suction and discharge valve sections is approximately 420 cm 2 is.

[0070] Referring now to Figure 2b, a second working chamber volume 2b is provided. An intake valve section 6b is also provided, with the intake valve section 6b partially provided on the visible side shown in Figure 2b and partially provided in the same position on the non-visible side. A discharge valve section 7b is also provided. The intake valve section 6b is off-90 degrees relative to the cylinder axis Lb, and the discharge valve section 7b is at 90 degrees relative to the cylinder axis.

[0071] Cylinder 2b has a diameter d2b of 210 mm and inlet valve section 6b extends a longitudinal height l2b of 75 mm from the top of the head section. The available area for inlet valve section 6b is approximately 130 cm on either side. 2 Therefore, the total available area for the intake valve section 6b is approximately 260 cm 2 and the available area for the discharge valve section is approximately 200 cm 2 Therefore, the total available area for the suction and discharge valve sections is approximately 460 cm 2 is.

[0072] 2c and 2d, CAD models of working chamber volumes are shown, provided solely to assist in the explanation of the present invention. These models are provided as a base, modified working chamber volume for the following explanation of flow through the valve arrangement of the present invention.

[0073] Referring now to Figure 2c, a third working chamber volume 2c is provided. An intake valve section 6c is also provided, partially on the visible side and partially on the non-visible side shown in Figure 2c. That is, intake valve section 6c is continuous around the periphery of working chamber volume 2c in the non-visible portion. A discharge valve section 7c is also provided. Intake valve section 6c is off-90 degrees relative to cylinder axis Lc, and discharge valve section 7b is at 90 degrees relative to the cylinder axis.

[0074] The cylinder 2c has a diameter d2c of 210 mm, and the intake valve section 6c has a longitudinal height l2c of 75 mm from the top of the head section. The intake valve section 6c has a truncated pyramidal shape with a plurality of side surfaces 6c'. Each of the side surfaces 6c' is a substantially flat surface tapering toward the apex. In this regard, the intake valve section 6c can be said to have a truncated pyramidal shape because the side surfaces 6c' together form a truncated pyramid.

[0075] By providing this truncated pyramidal shape, the available area for the intake valve section 6c is significantly improved. The available area for the intake valve section is approximately 38 cm on each side 6c'. 2 In the presently described example, twelve sides are provided. The total available area for the intake valve section 6c is therefore approximately 450 cm. 2 The discharge valve section 7c is provided as a flat area at 90 degrees to the cylinder longitudinal axis. As will be explained below, it is not essential that the discharge valve section 7c be provided at 90 degrees to the cylinder longitudinal axis; rather, this is presented here merely as an example. In this example, the available area for the discharge valve section is approximately 200 cm. 2 Therefore, the total available area for the suction and discharge valve sections is approximately 650 cm 2is.

[0076] Referring now to FIG. 2d, a fourth working chamber volume 2d is provided. An intake valve section 6d is also provided, with the intake valve section 6d being partially provided on the visible side and partially provided on the non-visible side as shown in FIG. 2d. That is, the intake valve section 6d is continuous around the periphery of the working chamber volume 2d in the non-visible portion. A discharge valve section 7d is also provided. The intake valve section 6d is out of a 90-degree orientation with respect to the cylinder axis Ld, and the discharge valve section 7d is disposed at 90 degrees relative to the cylinder axis Ld. Again, the discharge valve section 7d need not be 90 degrees relative to the cylinder axis Ld in other examples; this is provided merely as an example angle in this example.

[0077] The cylinder 2d has a diameter d2d of 210 mm, and the intake valve section 6d extends a longitudinal height l2d of 75 mm from the top of the head section. The intake valve section 6d has a truncated pyramidal shape with multiple side surfaces 6d'. Each of the multiple side surfaces 6d' is a substantially flat surface tapering to an apex. In this regard, the intake valve section 6d can be said to have a truncated pyramidal shape because the multiple side surfaces 6d' together form a truncated pyramid. The terms truncated pyramidal and truncated conical are intended to mean substantially truncated pyramidal and substantially truncated conical, respectively, and it will be understood that the terms truncated pyramidal and truncated conical include non-perfect truncated pyramidal and non-perfect truncated conical. The truncated pyramidal and truncated conical shapes may be imperfect for myriad design reasons, such as to aid in valve positioning, valve section machining, and valve and / or assembly sealing, to name just a few.

[0078] In the previous example shown in Figure 2c, each side 6c' is provided as a quadrilateral. In the example described with reference to Figure 2d, the side 6d' approximates a hexagon (two of the sides are arcs of an ellipse). It will be appreciated that such side 6d' arranged together as described still results in a truncated pyramidal shape for the intake valve section 6d.

[0079] By providing this truncated pyramidal shape, the available area for the inlet valve section 6d is significantly improved over the example shown in Figures 2a and 2b. The available area for the inlet valve section is approximately 70 cm on each side 6d'. 2 In the presently described example, six sides are provided. The total available area for the intake valve section 6d is therefore approximately 420 cm. 2 The discharge valve section 7d is provided as a flat area at 90 degrees to the longitudinal axis of the cylinder. The available area for the discharge valve section is approximately 200 cm 2 Therefore, the total available area for the suction and discharge valve sections is 620 cm 2 is.

[0080] In the presently described truncated pyramidal shapes shown in Figures 2c and 2d, six and twelve sides are provided, although it will be understood that in other examples any number of sides greater than three may be provided.

[0081] 3 and 4, the use of a truncated pyramidal suction valve section in a valve arrangement for a piston compressor will now be described. Referring to Figure 3, there is shown a valve arrangement 100 for a piston compressor (not shown). The valve arrangement 100 comprises the main components of an intake valve section 200 and a discharge valve section 300. The valve arrangement 100 is shown as being utilised within a cylinder head 400 of the piston compressor. It will be appreciated that the intake valve section 200, in use, allows working fluid to be drawn into a working chamber 2' (only partially shown in Figure 3) of the piston compressor. Similarly, the discharge valve section 300, in use, allows working fluid to be discharged from the working chamber 2' of the piston compressor.

[0082] The suction valve section 200 and the discharge valve section 300 together form the working chamber head section 1200. That is, the suction valve section 200 and the discharge valve section 300 together form the upper portion of the working chamber 2' of the piston compressor when the valve arrangement 100 is assembled in use in the piston compressor.

[0083] The placement of the intake valve section 200 results in improved compressor performance by improving fluid flow through the intake valve section 200 without substantially affecting dead volume, which, as previously discussed, has a significant impact on overall performance.

[0084] In this regard, the intake valve section 200 has a truncated pyramidal shape having a plurality of sides 210 including a first side 211, a second side 212, a third side 213, a fourth side 214, a fifth side 215, and additional sides not visible in the cross-sectional view shown in FIG. 3.

[0085] Although not shown in the figures, it will be understood that the piston in the piston compressor can stroke unimpeded from below into the working chamber head section. In this regard, the piston used with the presently described valve arrangement may be optimally configured to match the shape of the described valve arrangement. That is, because the inlet valve section 200 has a truncated pyramidal shape, the piston may also have a truncated pyramidal shape that matches the shape of the inlet valve section 200. In other words, the piston crown may be formed with a shape complementary to the shape of the working chamber head section 1200.

[0086] Each of the plurality of sides 210 is substantially flat so that a valve requiring a flat surface can be positioned on one or more of the sides 210 . 3, the first side 211 includes a plurality of intake ports 220, including a first intake port 221, a second intake port 222, a third intake port 223, a fourth intake port 224, a fifth intake port 225, and a sixth intake port 226. The intake ports 220 are configured to provide fluid communication through the intake valve section 200 such that, in use, working fluid may be drawn into the working chamber through the intake ports 220.

[0087] As shown in Figure 4, the intake valve section 200 includes a first self-actuating check valve in the form of a first reed valve 231. The first reed valve 231 includes a first finger blade 231' and a second finger blade 231'' arranged to open and close the intake port 220 (not visible in Figure 4), as will now be described.

[0088] The first finger blade 231′ is positioned to open and close the first intake port 221, the second intake port 222, and the third intake port 223, and the second finger blade 231″ is positioned to open and close the fourth intake port 224, the fifth intake port 225, and the sixth intake port 226. In the currently described example, the first finger blade 231′ and the second finger blade 231″ are integral. This results in a larger first reed valve 231 and allows for easier and faster production and assembly when compared to when the first finger blade 231′ and the second finger blade 231″ are provided separately. However, in some alternative examples (not shown), the first finger blade 231′ and the second finger blade 231″ are provided separately, i.e., non-integrally.

[0089] The arrangement shown with three ports 221, 222, 223 arranged with an associated first finger blade 231′ and another three ports 224, 225, 226 arranged with an associated second finger blade 231″ is merely one example. In alternative examples, there may be fewer or more ports and / or fewer or more finger blades. For example, there may be one finger blade arranged to open and close six ports. In some examples, the finger blades may be arranged to open and close a square or rectangular array of ports, rather than a single row of ports as in the currently described example.

[0090] As previously mentioned, reed valves require some form of retainer, typically in the form of a stop plate. The retainer is typically a curved, relatively rigid piece of sheet metal shaped to "roll" the reed element against its curved surface, both to limit movement of the reed element and thus guide it, and to prevent damage that might otherwise result from excessive bending during operation. As previously mentioned, other prior art retainers are in the form of retainer plates that are fixed a certain distance from the reed element, often with a spring element between the plate and the reed element. The reed element in the currently described example is, as will be explained, a finger blade 231', 231" that is retained without the use of a separate retainer as in the prior art.

[0091] 5, it can be seen that the discharge valve section 300 comprises a plurality of discharge ports 320. The plurality of discharge ports 320 comprises a first discharge port 321, a second discharge port 322, a third discharge port 323, a fourth discharge port 324, etc. Each of the plurality of discharge ports 320 is configured to provide fluid communication through the discharge valve section 300 such that, in use, working fluid can be discharged from the working chamber through the discharge port 320.

[0092] The discharge port 320 in the presently described example is provided as a curved slot in the discharge valve section 300. It will be appreciated that in alternative examples the discharge port 320 may be provided as a circular hole, a rectangular slot, or any other shape, provided that fluid communication is provided throughout the discharge valve section 300 in use.

[0093] 3 and 4, the discharge valve section 300 includes a stopper plate 331. The stopper plate 331 is positioned to prevent movement of a reed valve element (not shown) configured to open and close the discharge port 320.

[0094] In the currently described example, the discharge valve section 300 is substantially planar and oriented perpendicular to the longitudinal axis of the cylinder. It will be appreciated that in other alternative examples, the discharge valve section 300 may be shaped as a truncated pyramid or a truncated cone. Alternatively, the discharge valve section 300 may have a wedge-shaped cross section, as previously described.

[0095] 3 and 4, the first outlet port 321 is configured to block movement of the first finger blade 231′. Thus, the first outlet port 321 provides the retention function typically provided by a dedicated retainer or stop plate in prior art examples. However, because the first outlet port 321 is configured to block movement of the first finger blade 231′, a dedicated retainer or stop plate is not required. In prior art examples, a dedicated retainer or stop plate increases dead volume within the actuation chamber, so eliminating the dedicated retainer or stop plate is advantageous, especially when the first finger blade 231′ can be stopped by the first outlet port 321 without significantly increasing dead volume.

[0096] Although not described herein for brevity, it will be understood that each of the discharge ports 320 may be configured to block the movement of one or more of the finger blades. That is, in some examples, one discharge port may block the movement of multiple finger blades or all of the finger blades. In alternative examples, each discharge port may block the movement of a single finger blade. It will also be understood that not all discharge ports must necessarily block the movement of finger blades. Furthermore, it will be understood that a combination of discharge ports configured to block some of the finger blades and other separate retainers or catches configured to block the movement of other finger blades may be provided.

[0097] Figures 3a and 4a show the same arrangement as shown in Figures 3 and 4, but now with the cylinder 401 visible. As before, the working chamber 2' is defined by the piston (not shown), the cylinder 401, and the working chamber head section 1200. The piston is not shown for clarity, as it reciprocates (i.e. moves up and down) within the cylinder 401 in use.

[0098] The working chamber 2' has an upper portion 401A and a lower portion 401B. In Figure 3a, it can be seen that the third intake port 223 is oriented towards the upper portion 401A of the working chamber 2'. It can also be seen that the first intake port 221 and the second intake port 222 are oriented towards the lower portion 401B of the working chamber 2'.

[0099] It will be appreciated that, in use, the piston strokes from the upper portion 401A to the lower portion 401B from so-called "top dead center" (TDC) to so-called "bottom dead center" (BDC) when the piston compressor is performing its intake stroke. In this regard, as the piston leaves the TDC position, the majority of the flow of working fluid by intake into the working chamber 2' should be directed towards the upper portion 401A of the working chamber 2'. By providing an upward slope for the third intake port 223, working fluid is conveyed from the third intake port 223 through the third intake port 223 to the upper portion 401A of the working chamber 2'.

[0100] As the piston continues to move downward, the working chamber 2′ expands, which becomes filled with working fluid from the plurality of intake ports 220. In this regard, as the piston continues to move downward (i.e., towards and into the lower portion 401B), working fluid is conveyed to the working chamber 2′ from the first port 221 and the second port 222, which are conveniently oriented towards the lower portion 401B of the working chamber 2′. By providing the first intake port 221 and the second intake port 222 with a downward inclination, the working fluid is conveyed from the first intake port 221 and the second intake port 222 to the lower portion 401B of the working chamber 2′ via the first intake port 221 and the second intake port 222.

[0101] Furthermore, in the described example, the first finger blade 231′ is positioned such that the first finger blade 231′ opens from the side closer to the upper portion 401A of the working chamber 2′. It is advantageous to orient the ports positioned at the open ends of the finger blades so that they move away from the finger blades as they open. That is, improved fluid flow can be achieved by directing the flow through the third port 223 in an upward direction while the first finger blade 231′ opens in a downward direction. In other words, the flow through the third port 223 is directed toward the upper portion 401A while the first finger blade 231′ opens in a direction toward the lower portion 401B.

[0102] In some examples, each of the plurality of intake ports 220 may be oriented at a particular inclination (either upward or downward), or in some alternative examples, only some of the plurality of intake ports 220 may be oriented at a particular inclination (either upward or downward).

[0103] The term inclined is intended to mean that the referenced intake port is oriented into the working chamber non-perpendicular to the longitudinal axis Le. The term upward is intended to refer to the example described with reference to the figures and the viewing orientation provided. Thus, more generally, the term upward refers to the direction of the intake port toward the upper portion 401A, while the term downward refers to the direction of the intake port toward the lower portion 401B.

[0104] It will be appreciated that each of the plurality of intake ports 220 may be provided as a substantially straight port, or one or more of the plurality of intake ports 220 may be provided with a portion that is disposed perpendicular to the cylinder longitudinal axis Le. In this regard, an intake port may include a portion that is perpendicular to the cylinder longitudinal axis Le and be disposed to direct working fluid through the intake port in a fluid flow path that is not perpendicular to the cylinder longitudinal axis Le. For example, an intake port may include a vertically disposed portion that transitions into a curved or angled portion further along the flow path through the intake port.

[0105] Thus, in this disclosure, the terms slope, up, and down refer to the specific configuration of the intake port, i.e., the flow path of the fluid as it leaves the intake port, rather than the specific shape of the port, for example, within the material through which the intake port is drilled.

[0106] The terms upward tilt and downward tilt are used with respect to the orientation shown in Figures 3a and 3b. It will be understood that these terms are intended to mean that the respective ports are oriented towards the upper portion 401A or lower portion 401B of the working chamber 2'. The exact tilt provided will depend on many factors related to the exact geometry and configuration of the working chamber head section 1200 and cylinder 401.

[0107] 3b and 3c, detailed views of the intake valve section 200 shown in FIG. 4 are provided. It will again be appreciated that the intake valve section 200 allows working fluid to be drawn into the working chamber 2' (only partly shown in Figures 3b and 3c) of the piston compressor in use, and similarly the discharge valve section 300 allows working fluid to be discharged from the working chamber 2' of the piston compressor in use.

[0108] The placement of the intake valve section 200 provides improved compressor performance by improving fluid flow through the intake valve section 200 without substantially affecting dead volume.

[0109] As previously mentioned, and as can now be clearly seen in Figures 3b and 3c, the first side 211 is provided with a plurality of intake ports 220, including a first intake port 221, a second intake port 222, a third intake port 223, and a further intake port (not visible in Figures 3b and 3c). The intake ports 220 are configured to provide fluid communication through the intake valve section 200 so that, in use, working fluid may be drawn into the working chamber 2' via the intake ports 220.

[0110] Figures 3b and 3c show the first finger blade 231' of the first reed valve 231 in the closed and open positions, respectively. The first finger blade 231' is retained without the use of a separate retainer as in the prior art, as will be explained in more detail herein.

[0111] The discharge valve section 300 includes a first discharge port 321, a second discharge port 322, a third discharge port 323, and so on. As previously mentioned, the first discharge port 321 is configured to block movement of the first finger blade 231′. In this regard, the first discharge port 321 may match the shape of the first finger blade 231′ such that, in use, the first finger blade 231′ can be received within the first discharge port 231 to block movement of the first finger blade 231′. Thus, the first discharge port 321 provides a retention function typically provided by a dedicated retainer or stop plate in prior art examples. However, because the first discharge port 321 is configured to block movement of the first finger blade 231′, a dedicated retainer or stop plate is not required.

[0112] Referring specifically to FIG. 3c, it can be seen that the first finger blade 231' is held by the first discharge port 321 when the first finger blade 231' moves to the open position.

[0113] The first discharge port 321 may also be specifically shaped and positioned to align with the orientation and geometry of the first finger blade 231' during operation, thereby achieving optimal movement of the blade, which may further reduce friction and wear.

[0114] As mentioned above, the first finger blade 231′ is positioned such that the first finger blade 231′ opens from the side closer to the upper portion 401A of the working chamber 2′. It is advantageous to orient the ports located at the open ends of the finger blades so that they move away from the finger blades as they open. That is, improved fluid flow can be achieved by directing the flow through the third port 223 in an upward direction while the first finger blade 231′ opens in a downward direction. In other words, the flow through the third port 223 is directed toward the upper portion 401A while the first finger blade 231′ opens in a direction toward the lower portion 401B.

[0115] 3b and 3c, the first port 221 and the second port 222 are arranged such that their respective longitudinal port axes 221A, 222B are perpendicular to the first finger blade 231′ and the internal geometry of the intake valve section 200 inside the working chamber 2′. In contrast, the third port 223 is arranged such that its longitudinal port axis 223A is not perpendicular to the first finger blade 231′ and the internal geometry of the intake valve section 200 inside the working chamber 2′.

[0116] The presently described arrangement, providing upper ports oriented non-perpendicular to the first finger blade 231′, allows the aforementioned ports to direct fluid to the upper portion 401A of the working chamber 2′, while the lower ports direct fluid to the lower portion of the working chamber 2′. As the working chamber 2′ expands (i.e., as the piston moves downward), which becomes filled with working fluid from the multiple intake ports 220, the lower ports (in this case, the first port 221 and the second port 222) act to provide working fluid to the lower portion of the working chamber 2′, while one or more upper ports (in this case, the third port 223) act to provide working fluid to the upper portion 401A.

[0117] Referring now to FIGS. 3d and 3e, an alternative arrangement of the first finger blade 231'1 is provided, where FIG. 3d shows the first finger blade 231'1 in a closed position and FIG. 3e shows the first finger blade 231'1 in an open position. This arrangement is similar to the arrangement provided above in FIGS. 3b and 3c. However, the first finger blade 231'1 is arranged to open from the side closer to the lower portion 401'B of the working chamber 2'1. The first finger blade 231'1 is arranged to open and close the first port 2211, the second port 2221, and the third port 2231, as in the previous example. However, in the currently described example shown in FIGS. 3d and 3e, the first finger blade 231'1 is not blocked or held by the discharge port. Instead, as shown in FIG. 3e, a stop catch 231′A is provided that is configured to block the movement of the first finger blade 231′1. The stop catch 231′A is a relatively small catch that protrudes from the inner surface of the inlet valve section 201 and is configured to block further opening movement of the first finger blade 231′1. In this regard, no dedicated retainer or stop plate is required. Because in prior art examples, a dedicated retainer or stop plate increases dead volume within the working chamber, it is advantageous to eliminate the dedicated retainer or stop plate and instead provide blocking of the first finger blade 231′1 using the stop catch 231′A without significantly increasing dead volume.

[0118] Although not shown herein for brevity, in some examples, multiple stop catches 231'A may be provided that are configured to block the movement of one or more finger blades. That is, in some examples, one stop catch 231'A may block the movement of multiple finger blades or all of the finger blades. In alternative examples, each stop catch 213'2 may block the movement of a single finger blade.

[0119] Referring now to Figures 3f and 3g, an alternative second finger blade 231'2 arrangement is provided, where Figure 3f shows the second finger blade 231'2 in a closed position and Figure 3g shows the second finger blade 231'2 in an open position. This arrangement is similar to the arrangement provided above in Figures 3d and 3e. The second finger blade 231'2 is arranged to open and close the first port 2212, the second port 2222, and the third port 2232, as in the previous example. However, in the currently described example shown in Figures 3f and 3g, the second finger blade 231'2 is not provided with a stop catch protruding from the inner surface of the intake valve section and configured to prevent further opening movement of the finger blade. Instead, as can be clearly seen in FIGS. 3f and 3g, the second finger blade 231'2 is arranged with a hook 231'B attached to the open end of the second finger blade 231'2. In the currently described example, the hook 231'B is a separate component attached to the end of the second finger blade 231'2. In an alternative example (not shown), the second finger blade 231'2 and the hook 231'B may be integrally formed. In an alternative example (not shown), the blocking of the finger blade 231'2 may be provided by formations other than hooks, such as pins, needles, notches, or any other suitable formations, formed or attached to the open end of the finger blade 231'2. Such formations may similarly be matched with recesses 231'C or other geometric shapes molded for the purpose of capturing such formations.

[0120] 3f and 3g, the intake valve section 202 includes a recess 231'C configured to match the shape of the hook 231'B such that the hook 231'B can move within the recess 231'C but is prevented from moving outward. By connecting the hook 231'B with the second finger blade 231'2, movement of the second finger blade 231'2 is also prevented in a similar manner to the previous example, but without the need to form a feature protruding into the working chamber 2'2.

[0121] In prior art examples, a dedicated retainer or stop plate inside the working chamber increases the dead volume within the working chamber, so it is advantageous to eliminate the dedicated retainer or stop plate and instead use the hook 231'B and correspondingly formed recess 231'C to provide blocking of the second finger blade 231'2 without significantly increasing the dead volume. Referring to Figures 5 and 6, further details of a possible arrangement of the cylinder head 400 are now provided. Figure 5 shows a plan view of the cylinder head 400, and Figure 6 shows an isometric view of the cylinder head 400.

[0122] The cylinder head 400 includes the aforementioned intake valve section 200 (not visible in Figures 5 and 6) and discharge valve section 300. The cylinder head 400 includes a plurality of cylinder head bolt bosses 410, including a first cylinder head boss 411, a second cylinder head boss 412, a third cylinder head boss 413, a fourth cylinder head boss 414, a fifth cylinder head boss 415, and a sixth cylinder head boss 416, each of which is configured to receive a cylinder head bolt (not shown) in use to fasten the cylinder head 400 to a cylinder (not shown).

[0123] The cylinder head 400 further includes an extension cup 500 defining a discharge channel 510 that allows discharged working fluid to be removed from the working chamber 2' (not visible in Figures 5 and 6) through the discharge channel 510, as will be described in more detail below. The extension cup 500 includes a plurality of discharge valve section bolt bosses 520, including twelve discharge valve section bosses, each of which is configured to receive a discharge valve section bolt (not shown) in use to tighten the top plate 600 (shown in Figures 3 and 4) to the cylinder head 400.

[0124] 3-6, it can be seen that the intake valve section 200 is extended at its upper end to form an extension cup 500. By extending the intake valve section 200, the need for extending multiple discharge valve section bolt bosses 520 on the front surface of the intake valve section 200, which would obstruct the flow path of the working fluid into the intake valve section 200, is eliminated. The extension cup 500 therefore maintains an unobstructed flow path for the working fluid into the intake valve section 200 so that fluid flow can be optimized, leading to better performance of the piston compressor.

[0125] Continuing with reference to Figures 3-6, it can be seen that the cylinder head 400 comprises a plurality of outer bolt bosses 420, including twelve outer bolt bosses (including one boss 420' located in a more central portion of the cylinder head 400), each of which is configured to receive an outer bolt (not shown) in use to fasten the top plate 600 (not shown in Figures 3 and 4) and cylinder head 400 to a main compressor block (not shown).

[0126] It will be appreciated that the intake channel 200A is formed without obstruction, allowing for smooth fluid flow of the working fluid being drawn into the working chamber in use. As previously mentioned, the outlet channel 510 is also clearly visible in Figures 3 and 4.

[0127] In summary, the cylinder head 400 is attached to the cylinder in use by means of cylinder head bolts (not shown) that are provided through the cylinder head bolt bosses 410. The top plate 600 is attached to the extension cup 500 by means of discharge valve section bolts (not shown) that are provided through the discharge valve section bolt bosses 520. The top plate 600 is attached to the cylinder head 400 at an outer portion thereof by means of outer bolts (not shown) that are provided through the outer bolt bosses 420, 420'.

[0128] In some alternatives (not shown), the discharge channel 510 may be provided with a separate discharge pipe that may be advantageously secured to the cylinder head 400 and top plate 600 by the same discharge valve section bolts that are tightened into the discharge valve section bolt bosses 520.

[0129] Because a very tight seal is formed between the extension cup 500 and the top plate 600, it is highly desirable to provide a first gasket (not shown) between the extension cup 500 and the top plate 600. Additionally, because a very tight seal is formed between the cylinder head 400 and the top plate 600 at the outer bolts, it is highly desirable to provide a second gasket (not shown) between the cylinder head 400 and the top plate 600.

[0130] 3-5, the discharge valve section 300 is provided with a hydrolock prevention means in the form of a spring 700. As previously mentioned, the discharge valve section 300 includes a stop plate 331. The stop plate 331 is positioned to prevent movement of a reed valve element (not shown) configured to open and close the discharge port 320. During normal compressor operation, the spring 700 attaches the stop plate 331 to the cylinder head 400, instead of using, for example, a threaded bolt. In the unlikely event that a malfunction in the compressor operation results in the presence of a large amount of liquid in the working chamber during the compression and / or discharge strokes, the stop plate 331 will lift by pushing upward on the spring 700, preventing serious damage to the compressor resulting from excessive force that would otherwise be exerted on the stop plate 311.

[0131] In an alternative example (not shown), the hydrolock prevention means may be provided in the form of multiple springs. In some examples, the multiple springs may be spaced apart near the periphery of the stopper plate 331. In some examples, only multiple springs located near the periphery of the stopper plate 331 may be provided, while in other examples, there may be one or more springs in the center of the stopper plate 331, along with multiple springs located near the periphery of the stopper plate 331. It will be appreciated that when multiple springs are used, the force required for each spring is reduced because the load is shared across all of the multiple springs. Providing some or all of the springs near the periphery of the stopper plate 331 may result in improved flow within the discharge channel 510 compared to a single centrally located spring 700.

[0132] 3 and 4, there is further provided an insulating element 800 disposed between the discharge channel 510 and the suction channel 200A. It will be appreciated that when the piston compressor is used in a high temperature heat pump, the suction channel 200A carries a low temperature working fluid and the discharge channel 510 carries a high temperature working fluid. The insulating element 800 is provided to reduce or eliminate heat leakage between the suction channel 200A and the discharge channel 510.

[0133] While in the currently described example, the intake valve section 200 is generally disposed in a truncated pyramidal section, and the discharge valve section 300 is generally disposed in that section at 90 degrees relative to the longitudinal axis of the cylinder, it will be understood that in alternative examples, any portion of the truncated pyramidal section may be used as part of the discharge valve section, and / or any portion of the section at 90 degrees relative to the longitudinal axis of the cylinder may be used as part of the intake valve section. It is therefore emphasized here that the terms truncated pyramidal and truncated conical are used herein to refer to the general shape of the intake section, and do not exclude the possibility that a portion, such as two or four sides, may be used as part of the discharge valve section. In addition, the terms truncated pyramidal and truncated conical do not exclude the possibility that a portion, such as two or four sides, may be used for a different purpose or may be absent; in this context, the shape would still be considered truncated pyramidal or truncated conical in such cases.

[0134] Referring to FIG. 7, an alternative valve arrangement 100′ for a piston compressor (not shown) is shown. The valve arrangement 100′ includes the major components of an inlet valve section 200′ and a discharge valve section 300′. The valve arrangement 100′ is shown as being utilized within a cylinder head 400′ of a piston compressor. Most of the configuration of the alternative valve arrangement 100′ is the same as the valve arrangement described with reference to FIGS. 3-6 and will not be described in detail for the sake of brevity. The difference between the configuration described with reference to FIGS. 3-6 and the alternative arrangement shown in FIG. 7 is that the discharge valve section 300′ is configured in a generally flat configuration in FIGS. 3-6 and partially angled in FIG. 7. In this regard, it can be seen that the discharge valve section 300′ has a frustoconical first portion 300′A and a flat second portion 300′B that is disposed perpendicular to the cylinder axis. As previously mentioned, the discharge valve section 300′ in other examples may be provided in a variety of configurations. For example, the discharge valve section 300' may be provided as a cone, a pyramid, a truncated cone, or a truncated pyramid.

[0135] As previously mentioned, a geometric frustum is a three-dimensional geometric shape formed by the volume between two parallel planes and a polyhedron, often a pyramid or a cone. Thus, in geometric shapes, a truncated cone shape is the same as a truncated cone shape, and a truncated pyramidal shape is the same as a truncated pyramidal shape. In this disclosure, the terms truncated cone and truncated pyramidal are not limited to geometries between two parallel planes. While it may often be convenient to provide a valve section geometry between two parallel planes, the terms truncated pyramidal and truncated conical are not limited to truncated portions between two parallel planes. Rather, it will be understood that a truncated portion may be formed between two non-parallel planes.

[0136] As previously mentioned, a compressor can have one or more cylinders, each cylinder having its corresponding set of suction valve sections and discharge valve sections. Throughout the above disclosure, for clarity and brevity, reference is made to a single cylinder (and corresponding piston, suction valve section, discharge valve section, etc.). It will be understood that any single cylinder may be a single cylinder within a system of multiple cylinders (and corresponding piston, suction valve section, discharge valve section, etc.). In this regard, one or more cylinders of a multi-cylinder system may be as described herein. In some examples, all of the cylinders of a multi-cylinder system may be as described herein. In some examples, all of the cylinders of a multi-cylinder system may be as described herein and may be of substantially the same configuration.

[0137] 8 and 9, an alternative arrangement of a cylinder head 4000 will now be described. The cylinder head 4000 is configured to be arranged with two cylinders. For simplicity, only a two-cylinder cylinder head 4000 is described, although it will be appreciated that in other examples (not shown), cylinder heads for assemblies having three, four, five, six, or more cylinders may be provided.

[0138] FIG. 8 shows a cross-sectional view through the cylinder head 4000, and FIG. 9 shows an isometric view of the cylinder head 4000. The cylinder head 4000 comprises a first head section 4001 and a second head section 4002. The first head section 4001 is configured, in use, to channel and receive hydraulic fluid from a working chamber of a first cylinder (not shown) attached to the first head section 4001, and the second head section 4002 is configured, in use, to channel and receive hydraulic fluid from a working chamber of a second cylinder (not shown) attached to the second head section 4002.

[0139] The first head section 4001 comprises a first inlet valve section 2001 and a first discharge valve section 3001. Similarly, the second head section 4002 comprises a second inlet valve section 2002 and a second discharge valve section 3002. The first and second inlet valve sections 2001 and 2002, and the first and second discharge valve sections 3001 and 3002, are substantially the same as the inlet valve section 200 and discharge valve section 300 described above, and therefore a repetition of these details will not be repeated here for the sake of brevity.

[0140] Further, as in the above-described example, the first head section 4001 has a first extension cup 5001 forming a first discharge channel 5101, and the second head section 4002 has a second extension cup 5002 forming a second discharge channel 5102.

[0141] The discharge channels 5101, 5102 allow the discharged working fluid to be removed from the working chamber, as previously described. 8, first and second discharge funnels 5201 and 5202 are provided that are configured to receive and remove discharged working fluid from the discharge channels 5101, 5102. Optionally, in some examples, a common manifold (not shown) may be provided to which the first and second discharge funnels 5201 and 5202 connect.

[0142] Referring now to FIG. 9, in an isometric view, the cylinder head 4000 is shown without the top plate or discharge funnel for clarity. The cylinder head 4000 includes a first intake passage 4000A, a second intake passage 4000B, a third intake passage 4000C, and a fourth intake passage 4000D. In the currently described example, four intake passages 4000A, 4000B, 4000C, and 4000D are provided, although it will be understood that in alternative examples, any number of intake passages may be provided. Advantageously, each of the intake passages 4000A, 4000B, 4000C, and 4000D serves to channel working fluid from a common intake chamber (not shown) to both the first intake valve section 2001 and the second intake valve section 2002. That is, when working fluid is forced through the first intake valve section 2001, the working fluid may be drawn from a common intake chamber (not shown) through any or all of the four intake passages 4000A, 4000B, 4000C, 4000D.

[0143] During cyclic operation of two adjacent cylinders (not shown) that are supplied with working fluid from the cylinder head 4000, flow restriction may be reduced. Furthermore, the described arrangement may result in a larger working fluid damper, which may in turn reduce pressure fluctuations within the cylinder head 4000. Furthermore, as can be clearly seen in FIG. 9 , working fluid channeled to the first or second intake valve section 2001 or 2002 via the intake passages 4000A, 4000B, 4000C, 4000D may flow more freely to and between each intake valve section 2001, 2002 compared to the previously described arrangement in which each intake valve section is not in direct open fluid communication with another intake valve section, thereby reducing flow restriction and therefore pressure fluctuations.

Claims

1. A valve arrangement (100) for a piston compressor, comprising: an intake valve section (200); a discharge valve section (300); Equipped with The intake valve section (200) and the discharge valve section (300) together form a working chamber head section (1200); The intake valve section (200) has a truncated pyramidal shape. A valve arrangement (100).

2. 2. The valve arrangement (100) of claim 1, A valve arrangement (100) wherein the intake valve section (200) comprises at least a first self-actuating check valve (231).

3. 3. A valve arrangement (100) according to claim 2, comprising: The truncated pyramidal shape of the intake valve section (200) comprises a plurality of side surfaces (210); A valve arrangement (100), wherein the first self-actuating check valve (231) is located on a first side (211) of the plurality of sides (210) of the intake valve section (200).

4. A valve arrangement (100) according to claim 2 or 3, A valve arrangement (100), wherein the first self-actuated check valve (231) comprises a first reed intake valve (231).

5. 5. A valve arrangement (100) according to claim 4, comprising: the intake valve section (200) comprises at least a first intake port (221) configured to provide fluid communication through the intake valve section (200); A valve arrangement (100), wherein the first reed intake valve (231) comprises at least a first finger blade (231') arranged to open and close the first intake port (221).

6. 6. A valve arrangement (100) according to claim 5, comprising: the intake valve section (200) comprising a second intake port (222) configured to provide fluid communication through the intake valve section (200); The valve arrangement (100), wherein the first finger blade (231') is arranged to open and close the second intake port (222).

7. 6. A valve arrangement (100) according to claim 5, comprising: the intake valve section (200) comprising a second intake port (224) configured to provide fluid communication through the intake valve section (200); A valve arrangement (100), wherein the first reed intake valve (231) comprises a second finger blade (231'') arranged to open and close the second intake port (224).

8. 8. A valve arrangement (100) according to claim 7, comprising: A valve arrangement (100), wherein said first finger blade (231') and said second finger blade (231'') are integral.

9. 8. A valve arrangement (100) according to claim 7, comprising: A valve arrangement (100), wherein the first finger blade (231') and the second finger blade (231'') are non-integral.

10. A valve arrangement (100) according to any one of claims 5 to 9, further comprising: A valve arrangement (100) comprising a first finger catch (231'A) configured to block said movement of said first finger blade (231'1).

11. A valve arrangement (100) according to any one of claims 5 to 10, further comprising: A valve arrangement (100) comprising a second finger catch configured to prevent said movement of said second finger blade (231'').

12. A valve arrangement (100) according to any one of claims 5 to 9, comprising: The discharge valve section (300) includes a first discharge port (321) configured to provide fluid communication through the discharge valve section (300) and to prevent the movement of the first finger blade (231').

13. A valve arrangement (100) according to any one of claims 7 to 9, comprising: The discharge valve section (300) comprises a second discharge port (322) configured to provide fluid communication through the discharge valve section (300) and to prevent the movement of the first finger blade (231') and / or the second finger blade (231'').

14. A valve arrangement (100) according to claim 3 or according to any of claims 4 to 13 when dependent on claim 3, further comprising: The valve arrangement (100) includes a second self-actuating check valve located on a second side (212) of the plurality of sides (210) of the intake valve section (200).

15. 15. A valve arrangement (100) according to claim 14, comprising: The second self-actuated check valve comprises a second reed intake valve.

16. 16. A valve arrangement (100) according to claim 15, comprising: the intake valve section (200) comprising at least a third intake port configured to provide fluid communication through the intake valve section (200); The second reed intake valve includes at least a third finger blade positioned to open and close the third intake port.

17. 17. A valve arrangement (100) according to claim 16, comprising: the intake valve section (200) comprises a fourth intake port configured to provide fluid communication through the intake valve section (200); The third finger blade is arranged to open and close the fourth intake port.

18. 17. A valve arrangement (100) according to claim 16, comprising: the intake valve section (200) comprises a fourth intake port configured to provide fluid communication through the intake valve section (200); The second reed intake valve includes a fourth finger blade positioned to open and close the fourth intake port.

19. 19. A valve arrangement (100) according to claim 18, comprising: The valve arrangement (100), wherein the first finger blade and the second finger blade are integral.

20. 19. A valve arrangement (100) according to claim 18, comprising: A valve arrangement (100), wherein the first finger blade and the second finger blade are non-integral.

21. A valve arrangement (100) according to any preceding claim, comprising: the valve arrangement (100) has a central axis configured, in use, to be aligned with a longitudinal axis (Le) of the cylinder (401) of the piston compressor; The valve arrangement (100) is configured such that the discharge valve section (300) is perpendicular to the central axis, such that in use the discharge valve section (300) is at 90 degrees or substantially 90 degrees to the longitudinal axis (Le) of the cylinder (401).

22. A valve arrangement (100) for a piston compressor, comprising: an intake valve section (200); a discharge valve section (300); Equipped with The intake valve section (200) and the discharge valve section (300) together form a working chamber head section (1200); The intake valve section (200) has a substantially frustoconical shape with at least a first flat side surface. A valve arrangement (100).

23. 23. A valve arrangement (100) according to claim 22, comprising: The valve arrangement (100) wherein the intake valve section (200) comprises at least a first self-actuating check valve (231) located on the first flat side surface (211).

24. 24. A valve arrangement (100) according to any of claims 22 or 23, comprising: A valve arrangement (100), wherein the first self-actuated check valve (231) comprises a first reed intake valve (231).

25. 25. A valve arrangement (100) according to claim 24, comprising: the intake valve section (200) comprises at least a first intake port (221) configured to provide fluid communication through the intake valve section (200); A valve arrangement (100), wherein the first reed intake valve (231) comprises at least a first finger blade (231') arranged to open and close the first intake port (221).

26. 26. The valve arrangement (100) of claim 25, further comprising: A valve arrangement (100) comprising a first finger catch (231'A) configured to block said movement of said first finger blade (231').

27. 27. A valve arrangement (100) according to claim 25 or 26, comprising: The discharge valve section (300) includes a first discharge port (321) configured to provide fluid communication through the discharge valve section (300) and to prevent the movement of the first finger blade (231').

28. A valve arrangement (100) according to any one of claims 22 to 27, comprising: the valve arrangement (100) has a central axis configured, in use, to be aligned with a longitudinal axis (Le) of the cylinder (401) of the piston compressor; The valve arrangement (100) is configured such that the discharge valve section (300) is perpendicular to the central axis such that, in use, the discharge valve section (300) is at 90 degrees or substantially 90 degrees to the longitudinal axis of the cylinder (401).

29. A valve arrangement (100) for a piston compressor, comprising: an intake valve section (200); a discharge valve section (300) having a truncated pyramidal shape; Equipped with The intake valve section (200) and the discharge valve section (300) together form a working chamber head section (1200). A valve arrangement (100).

30. A valve arrangement (100) for a piston compressor, comprising: an intake valve section (200); a discharge valve section (300) having a substantially frustoconical shape with at least a first flat side surface (211); Equipped with The intake valve section (200) and the discharge valve section (300) together form a working chamber head section (1200). A valve arrangement (100).

31. A piston compressor, a cylinder (401) with a longitudinal axis (Le); a piston mounted in said cylinder (401) and linearly movable along said longitudinal axis (Le); A valve arrangement (100) according to any one of claims 1 to 30, A piston compressor comprising:

32. 32. The piston compressor of claim 31, The piston has a piston head section that is mated with the working chamber head section (1200).

33. A method of optimizing fluid flow through a valve arrangement (100), comprising: a. Providing a valve arrangement (100) according to any of claims 1 to 30; b. Inhaling a working fluid through the intake valve section (200); c. Discharging the working fluid through the discharge valve section (300); The method comprises:

34. 1. A method of operating a piston compressor, comprising: providing a piston compressor according to either claim 31 or 32; b. Inhaling working fluid into the cylinder (401) through the intake valve section (200); c) compressing the working fluid by linearly moving the piston along the longitudinal axis (Le); d. Discharging the working fluid from the cylinder (401) through the discharge valve section (300); The method comprises:

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