AT15704U1 - REFRIGERANT COMPRESSOR - Google Patents

Abstract

The invention relates to a refrigerant compressor comprising an electric drive unit, a cylinder housing (1), a crankshaft (3) drivable by the electric drive unit and a piston (2) driven by the crankshaft (3) in a working volume of the cylinder housing (1) cyclic compression of a refrigerant which can be conveyed into the working volume via a suction valve, comprising a suction opening (7) and a valve closing element (8) which cyclically closes the suction opening (7), preferably a valve spring. In order to ensure a continuous opening movement of the suction valve during the suction cycle, according to the invention an actuating device (14, 15, 23) is provided with which the valve closure element (8) can be opened in cycles.

Description

description

REFRIGERANT COMPRESSOR FIELD OF THE INVENTION

The invention relates to a refrigerant compressor with an electric drive unit, a cylinder housing, a drivable by the electric drive unit crankshaft and driven by the crankshaft, guided in a working volume of the cylinder housing piston for cyclic compression of a refrigerant, which via a mammary valve comprising a A mammalian opening and a valve closure element, which cyclically closes the mammal opening, preferably a valve spring, into which working volume can be conveyed.

Usually, a cylinder head assembly is secured to the cylinder housing, the cylinder head assembly comprising a mammalian opening and a valve closure member which intermittently closes the infant opening. Typically, the cylinder head assembly also includes a valve plate having the mammalian opening and a pressure port and a cylinder head cover forming a sealed cavity with the valve plate. The valve closure element of the mammal valve is generally arranged on the side of the valve side facing the piston, while a valve closure element of the pressure valve which cyclically closes the pressure opening is arranged on the side of the valve plate facing away from the piston. Mammal valve and pressure valve generally have a valve spring as a valve closure element. Between valve plate and cylinder housing or between the valve plate and the cylinder head cover is usually a sealing element, preferably in the form of a flat gasket arranged. As a rule, the valve plate is pressed over the cylinder head cover to the cylinder housing.

STATE OF THE ART

Refrigerant compressors, in particular hermetically sealed refrigerant compressor with a hermetically sealed compressor housing, have long been known and are mainly used in refrigeration units such as refrigerators or shelves. The refrigerant process as such has also been known for a long time. Refrigerant is heated by energy intake from the space to be cooled in an evaporator and finally superheated and pumped by the refrigerant compressor, also called refrigerant compressor, by a piston-cylinder unit, more precisely by a translationally moving in a cylinder housing piston to a higher pressure level where the refrigerant releases heat through a condenser and is returned to the evaporator via a restrictor, which reduces the pressure and cools the refrigerant. The movement of the piston is realized via a crankshaft driven by an electric drive unit. The electric drive unit usually comprises a stator and a rotor, wherein the rotor is non-rotatably connected to the crankshaft in order to drive the piston-cylinder unit.

During one revolution of the crankshaft, the piston is linearly moved during the suction stroke from a top dead center, in which the distance between a piston head and the valve plate is minimal, to a bottom dead center, in which the distance between the piston head and valve plate is maximum , Wherein, from a defined crank angle, refrigerant flows or is sucked via the mammal opening into a cylinder formed by the cylinder housing. In the subsequent compression stroke, the piston moves linearly from bottom dead center to top dead center, wherein refrigerant in the cylinder is compressed. From a defined crank angle, the pressure valve opens and the compressed refrigerant flows out of the cylinder via the pressure port.

According to the prior art, the mammalian valve opens in the suction cycle only when an opening force acting on the mammary valve by the in-cylinder pressure forming by the piston movement is greater than a closing force of the mammal valve. As a rule, the closing force of the mammal valve is determined by the spring constant of the valve spring of the mammal valve. A drawback of the state of the art is that an undefined state occurs during the opening movement of the mammal valve: as soon as the opening force and the closing force are approximately equal, the mammalian valve opens and refrigerant flows into the cylinder. As a result, however, the negative pressure correspondingly also decreases the opening force acting on the mammalian valve, so that the mammal valve, while actually undergoing the opening movement, actually performs a closing movement. Thus, in a certain crank angle range, a "fluttering" of the mammal valve takes place, in which the mammal valve does not make a continuous opening movement, but only temporarily opens or even undergoes several closing movements one after the other, thereby reducing the total amount during the suction stroke On the other hand, the "fluttering" of the mammalian valve causes a pulsation of the refrigerant in the refrigerant circuit, which causes an undesirable increase in the noise level of the refrigerant compressor.

OBJECT OF THE INVENTION

It is therefore an object of the invention to overcome the disadvantages of the prior art and to propose a refrigerant compressor in which a continuous opening movement of the mammal valve is ensured during the Saugtakts.

PRESENTATION OF THE INVENTION

This object is achieved in a refrigerant compressor according to the invention of the type mentioned above in that an actuating device is provided, with which the valve closure element of the mammal valve is opened in cycles. Tactically means that the actuator opens the valve closure element in principle every suction stroke of a working cycle, wherein a duty cycle corresponds to one revolution of the crankshaft.

The actuator according to the invention is a device which is provided in addition to the piston, which opens in the case of a valve spring this according to the prior art solely by the suction of refrigerant in the intake stroke. The actuator according to the invention can perform the opening of the mammal valve alone or, as in the case of a valve spring, perform supportive to the piston. For the latter case, it can thus be provided that the valve closure element can only be opened in a supportive manner by the actuating device.

Generally speaking, the object is thus achieved in that the mammalian valve is not or not only passively opened by the build-up in the cylinder suppression during the suction cycle, but that the mammal valve is actively opened via the actuator to the "flutter" of Prevent mammal valve.

It can be provided that the actuating device has a contact portion which is in engagement with the valve closure element or can be brought into engagement, wherein the valve closure element is intermittently openable by moving the contact portion. This embodiment corresponds to a mechanical actuation of the valve closure element. In this case, a contact portion is moved and opens the valve closure element. The contact portion may be firmly connected to the valve closure element and actuated by another element of the actuator. For example, the valve closure element could have a contact portion that projects outwardly through the mammal opening and is actuated outside the mammalian opening by another element of the actuator. Or the contact portion is on the one hand firmly with the valve closure element and on the other hand (directly as a single element of the actuator or indirectly via other elements) also mechanically connected to the piston and is actuated by the piston, which thus (also) by its movement in the suction cycle, the valve closure element mechanically a tensile force opens. Or the contact portion is fixedly connected to another element of the actuating device and is at least intermittently brought into engagement with the valve closure element. The contact portion can touch the valve closure element only during a certain phase of the suction cycle, but not during the pressure cycle. Or it touches the valve closure element also during the pressure cycle, but exerts no force on the valve closure element during the pressure cycle.

An embodiment provides that the contact portion with the side facing away from the piston of the valve closure element is in contact or can be brought to open this by exerting a compressive force. This embodiment is easy to implement in existing refrigerant compressors, since no retrofitting of elements in the working volume or on the piston is necessary. This embodiment allows controlled control of the opening of the mammal valve by the actuator, without affecting the function of the refrigerant compressor, and to keep the number of components of the actuator as low as possible. The mammalian valve usually opens in the direction of the cylinder and is arranged on the piston-facing side of the valve plate. By exerting a compressive force on the side of the mammal valve facing away from the piston, in other words by pressing the mammal valve from the side of the mammal valve facing away from the piston, at the beginning of the suction stroke, the continuous opening movement of the mammal valve can be achieved in a particularly simple manner be ensured.

It can be provided that the opening of the valve closure element with the actuating device at an equilibrium of the refrigerant pressure on both sides of the valve closure element can be introduced. This is the ideal time for opening the valve closure element and would in any case avoid "fluttering." This time occurs in a certain crank angle range, but is dependent on the back pressure, the dead space and the piston speed be determined on both sides of the valve closure element and the actuator could be actuated accordingly.

Since the effect of "fluttering" intermittently occurs in each case in a defined, definable crank angle range, it is sufficient according to an embodiment of the invention to open the mammal valve on the actuator in dependence of the crank angle of the crankshaft intermittently, so at least in that crank angle range in the "flutter" occurs in conventional refrigerant compressors, the contact portion of the actuating element is in contact with the mammalian valve. As a result, it is generally advantageous that the contact portion of the mammal valve is already at 90 ° to 60 ° crank angle before top dead center, ie already before the start of the suction cycle It is particularly advantageous if during a majority of the compression stroke the contact portion does not contact the mammal valve to prevent inadvertent opening of the mammal valve in that the mammal valve already releases itself from the contact section during the suction stroke, or at least after the opening movement, so that the usually abrupt closing movement of the mammal valve is not hindered by the contact section at the end of the suction stroke or at the beginning of the compression stroke.

Not only with regard to disturbing the contact portion when closing the mammal valve can be provided that by means of the actuating device, the valve closure element is cyclically closable. This would be the case, for instance, with a fully active mammalian valve, or if the contact section is mechanically connected to the piston. Or if a firm connection between actuator, contact portion and valve closure element is provided, so that the contact portion not only pushes the valve closure element in the open position, but also pulls back into the closed position.

In order to realize the dependence of the opening movement of the mammal valve in a simple and cost-effective manner, a mechanical coupling of the actuator is provided with the crankshaft in one embodiment, since the crank angle and thus also Saugtakt and compression stroke defined by nature over the crank angle of the crankshaft are. In this case, the actuating device outside the working volume comprises an actuating element which has the contact section which can be brought into contact with or in contact with the valve closure element. Thus, no - sometimes expensive - additional electrical controls or actuators are necessary. The mechanical coupling can be achieved by a variety of kinematic relationships. As described in more detail below, a single, for example, lever-like design, actuating element can be provided. But it is also conceivable that the actuating device comprises one or more further actuating element (s), which are in operative connection with each other.

In one embodiment of the invention it is provided that the actuating element is hinged to the cylinder housing or a cylinder head cover of a cylinder head assembly. Conventionally, the cylinder head assembly includes both a valve plate and a cylinder head cover, and the cylinder head assembly is fixed to a front side of the cylinder housing. In order to enable a simple connection of the actuating element to existing fastening openings on the cylinder head cover or on the cylinder housing, these components are particularly well suited for connection of the actuating element. The articulated connection allows a pivoting movement of the actuating element, which can be achieved kinematically simple to control movements in the actuator. Similarly, the proximity to the mammalian valve is provided by attachment to the cylinder head assembly or cylinder housing.

A further embodiment of the refrigerant compressor according to the invention provides that the actuating element is pivotally mounted about a parallel to the longitudinal axis of the crankshaft aligned pivot axis. Such alignment of the pivot axis ensures that the contact portion moves in a plane that is parallel to a bore axis of the mammalian opening, with the direction of the bore axis substantially corresponding to the opening direction of the mammalian valve. Thus, the opening movement of the mammal valve can be advantageously supported. Similarly, such an orientation of the pivot axis usually requires a lateral arrangement of the actuating element relative to the cylinder housing, since neither on the seen in the direction of the longitudinal axis of the crankshaft top nor on the underside of the cylinder head assembly is generally sufficient space available, since the space is taken for example by a suction and / or pressure silencer or an upper half of the compressor housing.

According to a preferred embodiment of the invention Kältemittelver-dichters is provided that the actuating device has a standing with an actuating portion of the actuating element in operative contact control, which control is rotatably connected to the crankshaft, said actuating element and control are designed such that a rotational Movement of the crankshaft in a pivoting movement or a translational movement of at least the contact portion of the actuating element is convertible. Through the interaction of the control element and the other components of the actuating device, in particular the actuating element, the mechanical coupling of the crankshaft to the contact section can be easily realized. The operative connection between the actuating section and the control element can be produced, for example, by direct contact or by interposition of further actuating elements. In this case, the control element may, for example, be of cam-shaped design, so that a deflection of a control element of the actuating device in the radial direction relative to the longitudinal axis of the crankshaft is effected by the different radial spacings of the side surface of the control element relative to the longitudinal axis of the crankshaft. In a further alternative embodiment variant, the control element can also have elevations and depressions in the form of mountains and valleys on the upper side or the underside of the control element, which effect a deflection of an element of the actuating element adjoining the control element in the axial direction relative to the longitudinal axis of the crankshaft.

If the operating portion of the actuating element directly to the control, so the actuating portion is deflected during a revolution of the crankshaft by the control. Basically, therefore, a translation of the rotation of the crankshaft in a translational movement of the contact portion is possible by the control. If the actuating element is designed as a lever, a pivoting movement of the contact section about a pivot point of the lever is made possible. If the kinematic relationships are selected accordingly, however, corresponds to the pivoting movement of the contact portion approximately a translational movement.

In a further preferred embodiment, the actuating device consists of the actuating element and the control element, so that no further movable components for kinematic conversion of the rotation of the crankshaft in a translational movement or a pivoting movement of the voltage applied to the control actuating portion of the actuating element must be provided.

In order to achieve a simple and inexpensive to produce or mountable structure of the actuator, in a further embodiment of the invention, it is provided that the control has a standing with the actuating portion of the actuating element in contact guide surface, wherein the guide surface eccentric to the longitudinal axis of the crankshaft is trained. Due to the contact between the guide surface and the actuating section, the radial deflection of the actuating section caused by the eccentric design of the guide surface takes place directly. The guide surface may be formed, for example, as a side surface of a designed as an eccentric with a preferably circular cross-section control. In this case, a spring element may be provided which presses the actuating portion against the control to ensure the contact between the control element and the actuating portion. It goes without saying that a guide surface formed in this way is also conceivable, if there is no direct contact with the actuating portion, but one or more components of the actuating device are interposed.

In a further preferred embodiment of the invention, it is provided that the guide surface is formed by an annular groove extending from one of the crankshaft facing or facing away from the crankshaft end face of the control. Due to the interaction of the groove and the actuating portion, wherein the actuating portion may be formed, for example, pin-shaped or bolt-shaped, the actuating portion is at least partially disposed within the groove. Thereby, the actuating portion is moved both radially outwardly and radially inwardly during a revolution of the crankshaft by the control, without an additional force, such as a spring force, must be exerted on the actuating portion to effect the deflection inward. The groove is designed as a closed ring, for example, with a circular or elliptical groove track, wherein both side surfaces of the groove form a guide surface. In order to reduce the noise level of the refrigerant compressor and to reduce an unbalanced running of the crankshaft, it is advantageous if the control element has a rotationally symmetrical shape with respect to a longitudinal axis of the crankshaft.

A particularly preferred embodiment of the refrigerant compressor according to the invention provides that the actuating element has a lever-shaped base body, wherein a first lever arm of the base body has the actuating portion and a second lever arm of the base body has the contact portion. Due to the lever shape of the body easily manageable kinematic relationships are available, so that the movement of the contact portion are precisely defined by the design and dimensioning of the two lever arms and by the positioning of a pivot point of the lever arm, which usually serves for articulated connection of the actuating element to the refrigerant compressor can. Both the contact portion and the actuating portion move on a pivoting track about the pivot point of the lever arm.

To connect the actuator articulated to the cylinder head assembly is provided in a further embodiment that the cylinder head cover of the cylinder head assembly forms a bearing for the actuator or that a holder is attached to the cylinder head cover of the cylinder head assembly, which bracket forms a bearing for the actuator. Due to the available space, the fact that the cylinder head cover is usually connected by means of fasteners on the cylinder housing, and the proximity to the mammal valve, the cylinder head cover is particularly well suited to the formation of the bearing of the actuator. In particular, when retrofitting existing cylinder head cover with actuators, it is advantageous if the bearing is formed by a, preferably by means of fastening elements for fastening the cylinder head cover itself, attached to the cylinder head cover bracket. It is advantageous in principle, when the bearing serves to support the pivot point of the lever-shaped base body.

To design the geometric shape of the lever-shaped main body of the actuating element, which is necessary for the mechanical coupling of the movement of the contact portion with the crankshaft is provided in a further embodiment of the refrigerant compressor according to the invention, that the main body of the actuating element at least one kink, preferably at least one Kink per lever arm, wherein a bending axis is aligned in each case substantially parallel to the longitudinal axis of the crankshaft. The orientation of the bending axis (s) ensures that the base body has at least one continuous base plane, wherein the base body is preferably flat. The creases have angular ranges of between 60 ° and 160 °, in particular between 90 ° and 160 °, preferably between 110 ° and 150 °, particularly preferably between 120 ° and 140 °. In an advantageous embodiment variant, the first lever arm has at least one kink, preferably two kinks, of between 115 ° and 145 °, while the second lever arm has a kink of approximately 90 ° +/- 10 °. It is advantageous if the second lever arm engages around the cylinder head cover such that the contact portion is arranged in alignment with the mammalian opening.

In order to keep the flow losses of the refrigerant as it flows through the mammal valve by the actuator, in particular by the contact portion as low as possible, is provided in a further embodiment of the invention, that a cross-sectional area of the contact portion of the actuating element small compared to a cross-sectional area of the Infant opening is. It is advantageous if the cross-sectional area of the contact section is at most 10%, preferably at most 5%, in particular at most 2.5%, particularly preferably below 2.5% of the cross-sectional area of the mammal opening.

In a particularly preferred embodiment of the refrigerant compressor according to the invention it is provided that the contact portion is formed by a resilient contact element, in particular spring wire or plastic. Due to the resilient properties, in particular of the spring wire or of the plastic, one or more of the following advantageous effects can be achieved: Due to the resilience of the contact element, the contact section can already be brought into contact with the mammal valve at the end of the ejection cycle without it being opened is because the contact element yields resiliently. By adjusting the spring constant of the contact element and the spring constant of the mammal valve, or the valve spring of the mammal valve, the opening time of the mammal valve is precisely adjustable. If the actuating element has a lever-shaped basic body and the region of the actuating element to which the contact element is fastened undergoes a pivotal movement, the pivotal movement of the contact section can be compensated by elastic deformation if the contact section is guided at least in sections in a guide, so that the contact section and thus the mammal valve contacted by the contact section is only moved linearly. If the contact element instead of spring wire made of plastic, here by the choice of the plastic, by the thickness and shape (straight or curved) as resilient properties as when using spring wire can be realized.

A further particularly preferred embodiment provides that the contact element is planar and has a bent connecting section, wherein the connecting section optionally connects a, preferably lever-shaped, basic body of the actuating element to the contact section. Due to the planar design of the contact element, the spring properties of the contact element can be particularly easily influenced by the geometric design. The resilient properties of the contact element can be adjusted via the bent connecting section, which is bent, for example, such that a pivoting movement of the actuating element is compensated essentially by torsion of the connecting section and not by a bending of the contact section.

According to a further particularly preferred embodiment of the invention it is provided that the contact portion is arranged to extend substantially parallel to a bore axis of the mammal opening and that the connecting portion has at least one V-shaped bend, wherein a plane formed by the contact element preferably parallel to the longitudinal axis the crankshaft is aligned. The at least partially arranged within the cylinder head assembly, for example within the cylinder head cover or within a suction muffler, arranged contact portion of the contact element is generally rectilinear in order to avoid flow losses during the inflow of the refrigerant. An above-described bending of the connecting portion can be achieved by at least one V-shaped bend of the connecting portion. It goes without saying that the rectilinear design of the contact portion is advantageous regardless of the shape of the bend. By aligning the plane of the contact element ensures that the movement of the actuating element can be used directly for the continuous opening of the mammal valve.

In a further particularly preferred embodiment of the invention it is provided that the contact portion of the actuating element is at least partially guided in a bore of the cylinder head cover of the cylinder head assembly and / or in a bore of a suction muffler, preferably an outlet of the suction muffler. Since the majority of the actuator is disposed outside the cylinder head assembly so as not to affect the flow of the refrigerant, and to bridge the distance between the crankshaft and the mammalian valve, it is necessary that at least the contact portion is guided inside the cylinder head assembly to contact the mammalian valve can. Therefore, it is necessary to provide access to the interior of the cylinder head assembly for the contact portion, which can also serve as a guide at the same time. This access is achieved in certain embodiments by a hole in the cylinder head cover. Usually, a suction muffler is provided whose outlet is directly connected to the mammal opening. Therefore, in corresponding cylinder head assemblies, an opening in the suction muffler is necessary to guide the contact portion to the mammalian valve. If the outlet of the suction muffler is pressed against the valve plate by a section of the cylinder head cover, the bore may need to pass through both the cylinder head cover and the outlet of the suction muffler.

In addition to the execution of the actuating element as a substantially pivotable lever and a translationally movable actuator is possible. In this case, the actuating element comprises a first, in particular straight, portion which is translationally movable parallel to the piston, and a second bent portion which engages behind the suction opening and carries the contact portion, so that it is also translationally movable parallel to the piston. The control element, which control element is connected in a rotationally fixed manner to the crankshaft, could have a guide surface which is in contact with the actuating element and which is formed eccentrically to the longitudinal axis of the crankshaft. The guide surface could be the peripheral surface of the control. The control could e.g. be cam-shaped or an eccentric disc and allow movement of the actuating element at the beginning of the suction stroke in the direction of the crankshaft, for example by a smaller radius. This movement could be effected for example by a spring. In this case, the contact portion is also moved in the direction of the crankshaft and presses the valve closure element from the outside. Thereafter, the actuator returns by contact with the control member in a position remote from the crankshaft position, where no pressure is exerted on the valve closure member by the contact portion. The straight portion of the actuating element may be guided in the cylinder housing. In particular, the straight portion of the actuator may be passed through the valve plate so that the bent portion is entirely in the volume of a cylinder head cover and the contact portion is also in the volume of a cylinder head cover. Thus, no openings for the passage of the actuating element are necessary in the cylinder head cover.

The subject invention also includes a method for operating a refrigerant compressor with an electric drive unit, a cylinder housing, a drivable by the electric drive unit crankshaft and a drivable by the crankshaft, guided in a working volume of the cylinder housing piston for the cyclic compression of a refrigerant , which is conveyed into the working volume via a mammalian valve comprising a mammalian opening and a valve closure element which cyclically closes the mammal opening, preferably a valve spring. In this case, an actuating device is provided with which the valve closure element at least supportive cyclically, so once per revolution of the crankshaft, is opened.

In this case, the actuating device in particular has a contact portion, which engages with the valve closure element or can be brought into engagement, wherein the valve closure element is opened by moving the contact portion cyclically.

The further embodiments of the method result from the above-described operation of the refrigerant compressor according to the invention.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail with reference to an embodiment. The drawings are exemplary and are intended to illustrate the inventive idea, but in no way restrict it or even reproduce it.

FIG. 1 shows a top view of a refrigerant compressor according to the invention in a first embodiment. FIG

Variant; Fig. 2 is a perspective view of essential components of the refrigerant compressor of FIG. 1; FIG. 3 shows a further perspective view according to FIG. 2; FIG. FIG. 4 is a perspective view of the refrigerant compressor of FIG. 1; FIG. FIG. 5 shows a section through the refrigerant compressor which is vertical with respect to FIG. 4

Fig. 1; Fig. 6 detail views of the actuating element of FIGS. 1-5; Fig. 7 is a schematic illustration of the crankshaft, actuator, and mammalian valve at selected crank angles; Fig. 8 is a plan view of a refrigerant compressor according to the invention in a two-th variant; 9 shows a vertical section with respect to FIG. 12 through the refrigerant compressor

Fig. 8; FIG. 10 is a plan view of FIG. 1, partly in section; FIG. 11 is a perspective view of the refrigerant compressor of FIG. 8, cut as in FIG. 10; FIG. 12 is a perspective view of the refrigerant compressor of FIG. 8. FIG.

WAYS FOR CARRYING OUT THE INVENTION

Figure 1 shows a plan view of a refrigerant compressor according to the invention, wherein the components of the refrigerant compressor are arranged in a hermetically encapsulated compressor housing, which is not shown here, to show the interior of the compressor housing can.

The refrigerant compressor comprises an electric drive unit comprising a stator and a rotor rotatably connected to a crankshaft 3 (see FIGS. 2 and 3). The crankshaft 3 can be driven by means of the electric drive unit, as a result of which a piston-cylinder unit operatively connected to an eccentrically arranged longitudinal axis 4 of the crankshaft 3 of the crankshaft 3 cyclically sucks or compresses refrigerant. The piston-cylinder unit comprises a cylinder housing 1 surrounding a cylinder and a piston 2 guided translationally therein (see FIG. 7). The piston 2 is connected via a connecting rod 13 with the crank pin 12 of the crankshaft 3, so that the piston 2 during a revolution of the crankshaft 3 passes through a suction stroke and a compression and exhaust stroke (see Fig. 7).

On a front side of the cylinder housing 1, a cylinder head sealing arrangement closing the cylinder 5 is attached, which comprises a valve plate 6 having a mammalian opening 7 and a pressure opening 9. On the valve plate 6, a mammal valve 8 which intermittently closes the mammal opening 7 and a pressure valve 10 which intermittently closes the pressure opening 9 are arranged, as can be seen in FIGS. 2 and 3. A cylinder head cover 11 forming a cavity with the valve plate 6 (see FIG. 4) closes the cylinder head arrangement 5. The cylinder head cover 11 is fastened to the front surface of the cylinder housing 1 via a plurality of fastening elements, in the present exemplary embodiment via four fastening elements, preferably screws 6 between the cylinder head cover 11 and cylinder housing 1 is clamped. As a rule, sealing elements, preferably gaskets, are arranged between cylinder head cover 11 and valve plate 6 or between valve plate 6 and cylinder housing 1 in order to ensure the tightness of cylinder head arrangement 5 with respect to the interior of the compressor housing. The pressure line, which leads away from the pressure opening 9, is formed here by the cylinder housing 1, wherein for the pressure line pressure silencer 41 are provided.

According to the invention, a mechanically coupled to the crankshaft 3 actuator 14 is provided for the mammalian valve 8, which will be described in detail below.

The actuating device 14 comprises an actuating element 15 for actuating the mammal valve 8 and a non-rotatably connected to the crankshaft 3 control element 23 which is in operative connection with an actuating portion 17 of the actuating element 15. The actuating element 15 comprises a lever-shaped main body 18 with a first lever arm 19 and a second lever arm 20, wherein the actuating portion 17 is formed on the first lever arm 19. In the present embodiment, the operating portion 17 is disposed in an end portion of the first lever arm 19.

The actuating element 15 is hingedly connected to the cylinder head cover 11 in order to allow a pivoting movement of the actuating element 15. In this case, the pivot axis 21 of the actuating element 15 is aligned parallel to the longitudinal axis 4 of the crankshaft 3 in order to achieve an opening movement of the mammal valve 8 by pivoting the actuating element 15 about the pivot axis 21.

The pivot axis 21 is formed by a bearing 30, which acts as a fulcrum of the lever-shaped main body 18. The bearing 30 is formed in the present embodiment by a bracket 29 attached to the cylinder head cover 11, wherein the bracket 29 is connected via fasteners, in the present case two fasteners on the cylinder head cover 11, see the two mounting holes in the holder 29 in FIG The holder 29 is arranged laterally to the cylinder housing 1 or to the cylinder head cover 11, wherein the upper side and lower side are respectively aligned in or against the longitudinal axis 4. The bracket 29 is formed as an angle, wherein a first leg of the bracket 29 rests against the front side of the cylinder head cover 11 and for attachment at least one, preferably exactly two mounting holes, and a second leg of the bracket 29 is aligned parallel to a side surface of the cylinder head cover 11 and the bearing 30 has. The bearing 30 is formed in the present embodiment by a bolt which is guided through a bearing opening of the actuating element 15 and the lever-shaped base body 18.

In alternative embodiments, the bearing 30 may also be formed directly on the cylinder housing 1 or on the cylinder head cover 11. The bearing 30 may be formed, for example, as a bolt-shaped projection of the cylinder head cover 11.

In prior art refrigerant compressors, the mammalian valve 8 is passively actuated by the depression formed in the cylinder during the suction stroke. During the first opening phase of the mammal valve 8, when the opening force exerted by the squeeze corresponds substantially to the closing force of the mammal valve 8, refrigerant flows into the cylinder via the partially released mammal opening 7, whereby the siphoning decreases and the opening force decreases again. This results in a so-called "fluttering" of the mammal valve 8, which is usually formed by a valve spring When "flapping" the mammal valve 8 performs one or more times a closing movement during the Saugtakts until the suppression by the inflowing refrigerant less is lowered as the necessary for the application of the opening force oppression. Due to this effect, on the one hand, the efficiency of the refrigerant compressor decreases because, in phases, during the suction cycle, no or less refrigerant enters the cylinder. At the same time it comes through the "flutter" to pulsations in the sucked refrigerant flow or in the refrigerant circuit, resulting in an undesirable noise.

FIGS. 2 and 3 now show the components of the refrigerant compressor according to the invention. For the sake of clarity, neither cylinder head cover 11 nor cylinder housing 1 or piston 2 are shown, among other things, in order not to obscure the other components. As mentioned above, the actuator 14 is mechanically coupled to the crankshaft 3 so that a contact portion 16 of the actuator 15 in response to the crank angle of the crankshaft 3 in contact with the mammal valve 8 can be brought to achieve a continuous opening movement of the mammal valve. Characterized in that the contact portion 16 at least during the opening movement of the mammal valve 8, the mammal valve 8 is contacted and moved via the mechanical coupling in dependence of the crank angle of the crankshaft 3, the mammal valve 8 is actively opened by means of the actuating element 15, wherein a closing movement of the mammal valve 8 during the opening phase is prevented by the contact with the contact portion 16.

In the present embodiment, the second lever arm 20 of the lever-shaped main body 18 of the actuating element 15 on the contact portion 16, wherein the contact portion 16 is preferably aligned with the mammal opening 7 and is formed or fixed in an end region of the second lever arm 20. The contact portion 16 is positioned in the region of the cylinder head assembly 5, that is on the cylinder housing 1 and the opposite side of the valve plate 6, so that the contact portion 16 with the cylinder housing 1 and the piston 2 opposite side of the mammal valve 8 contacted is. Thereby, the mammal valve 8 can be pressed by the contact portion 16 by the contact portion 16 exerts a compressive force on the mammal valve 8 by the coupled movement.

Since the contact portion 16 protrudes into the space of the cylinder head assembly 5 through which refrigerant flows during the suction stroke, the contact portion 16 has a small cross-sectional area compared to the cross-sectional area of the mammalian opening 7, the cross-sectional area of the contact portion 16 in the present embodiment being only occupies about 1% of the cross-sectional area of the mammal opening 7 in order to influence the flow of the refrigerant as little as possible.

The mechanical coupling of the actuator 14 is now carried out as described below: The control element 23 is disc-shaped and has a rotationally symmetrical outer shape relative to the longitudinal axis 4, wherein the crank pin 12 projects through an opening 28 of the control element 23. As a result, the control 23 is arranged below the connecting rod 13. On an upper, first end face 25 of the control element 23, an eccentrically arranged to the longitudinal axis 4 guide surface 24 is formed, which is directly in contact with the actuating portion 17 of the actuating element 15 in the present embodiment. The guide surface 24 is formed by an annular groove 27 in which, for example, bolt-shaped, actuating portion 17 of the actuating element 15 projects into it. The guide surface 24 is thereby formed at least by the two side walls of the groove 27, whereby the actuating portion 17 is movable through the guide in the groove both radially inwardly and radially outwardly, each relative to the longitudinal axis 4. The exact sequence of movements is based on the Fig. 7 explained.

Basically, by the control element 23 a conditional by the eccentric arrangement of the guide surface 24, dependent on the crank angle of the crankshaft 3 pivotal movement of the actuating element 15, more precisely the contact portion 16 to the bearing 30 and the pivot point of the lever-shaped base body 18 is reached. Thus, the contact portion 16 cyclically moves in the direction of the mammal valve 8 depending on the crank angle of the crankshaft 3 to ensure a continuous opening movement of the mammal valve 8 intermittently from the mammal valve 8 so as not to hinder the closing movement of the mammal valve 8.

In the present embodiment, the actuating element 15 comprises a contact portion 16 forming contact element 31 made of spring wire, so in the present case spring steel with a diameter of less than 1 mm, which is secured in an end portion of the second lever arm 20 on the lever-shaped base body 18, preferably via a clamping device is clamped. By the formation of the contact element 31 made of spring wire, for example, a compliance of the contact element 31 can be adjusted in order to adjust the opening time of the mammal valve 8 precisely. In the present embodiment, the contact element 31 has a bent connecting portion 32 which connects the contact portion 16 with the actuating element 15. The contact element 31 is flat, so in other words, all the bending axes are aligned parallel to each other. In the present exemplary embodiment, the connecting section 32 has a V-shaped bend, which extends obliquely downwards from the actuating element 15 in the direction of the longitudinal axis 4 and, after the tip of the Vs, extends obliquely upward in the direction of the longitudinal axis 4. The adjoining the connecting portion 32 contact portion 16 is straight and arranged substantially parallel to a bore axis of the mammal opening 7, wherein the contact portion 16, the mammal valve 8 preferably in the upper half of the mammal opening 7 contacted.

4 shows a further perspective view of the refrigerant compressor is shown, wherein the cylinder head cover 11 and an at least partially disposed within the cylinder head assembly 5 suction muffler 33 are shown. In Fig. 5, the refrigerant compressor of Fig. 4 is shown in section, wherein the piston 2 and connecting rod 13 are not shown. From the actuator 14 as the control element 23 and the lever 18 have been omitted and only the contact element 31 located. As a rule, the refrigerant flowing into the refrigerant compressor via a coolant supply line flows via the suction muffler 33 to the mammal opening 7, wherein an outlet 34 of the suction muffler 33, preferably via the cylinder head cover 11 or a spring arrangement, is pressed against the valve plate 6 by approximately gas-tight Make connection between the suction muffler 33 and mammal opening 7. In other words, the mammal valve 8 is completely covered by the outlet 34 of the suction muffler 33. In order to be able to bring the contact section 16 into contact with the mammal valve 8, a bore 35 is formed in the suction muffler 33 or in the outlet 34, in which the contact section 16 is guided at least in sections. Due to the small diameter of the spring wire and the small gap width between the bore wall and contact element 31, the losses in the inflow of the refrigerant are negligible. If the mammal opening 7 is also covered by a portion of the cylinder head cover 11 or by another element of the cylinder head assembly 5, it is necessary also in the cylinder head cover 11 and in the other element provide a bore 35 to actuate the mammal valve 8 can.

In Fig. 6 are detailed representations of the actuating element 15, consisting essentially of the lever-shaped base body 18 and the contact element 31, is shown. At the very top is a side view, where the pivot axis 21 of the main body 18 is located.

Below is a plan view from which the individual kinks 22a, 22b, 22c of the main body 18 can be seen. The main body 18 has a kink 22a, 22b per lever arm 19, 20 and a kink 22c between the two lever arms 19, 20 on the pivot axis 21. All three kink axes are each substantially parallel to the longitudinal axis 4 (see Fig. 2) of the crankshaft 3 is aligned. By aligning the bending axes is ensured that the base body 18 has a continuous base plane in which the base body 18 is flat, so here is in the plane of the drawing. The first lever arm 19 has a kink 22a of about 140 °. The kink 22c between the two lever arms 19, 20, has an angle of about 160 °, while the second lever arm 20 has a kink of about 90 °. The second lever arm 20 can therefore encompass the cylinder head cover 11 such that the contact section 16 is arranged in alignment with the mammal opening 7.

In Fig. 6 bottom left is a perspective view of the actuator 15 from above and right a perspective view of the actuator 15 shown from below.

Fig. 7 shows four schematic representations of crankshaft, actuator and mammal valve 8 at selected crank angles or positions of the piston 2. At the top left is the piston 2 at the end of the compression stroke, just before top dead center. The contact portion 16 is already in contact with the mammalian valve 8, but this is still closed. The contact portion 16 may already be 90 ° to 60 ° crank angle before top dead center in contact with the mammalian valve 8.

Only after top dead center does the contact portion 16 pass through the mammal opening and open the mammalian valve 8 by urging it inwardly away from the valve plate 6. This is shown in the upper right in FIG. 7. The time or crank angle, from which the contact section 16 opens the mammal valve 8, is predetermined here by the geometry of the actuating device 14. In addition to the contact portion 16, the mammalian valve 8 is also opened by the negative pressure in the cylinder.

Bottom left in Fig. 7, the suction stroke is already approaching its end, the piston has reached shortly before its bottom dead center. The contact portion 16 has opened the mammal valve 8 even further.

Right bottom of the beginning of the compression stroke is shown, so a piston position shortly after the bottom dead center. The contact portion 16 has left the mammal opening 7 again and thus does not contact the mammal valve 8 anymore.

8 shows a plan view of a refrigerant compressor according to the invention in a second variant. The construction of the refrigerant compressor is essentially the same as that of the first variant in FIGS. 1-7, except for the actuating device 14. The actuating device 14 for the mammalian valve 8, which is mechanically coupled to the crankshaft 3, here comprises an actuating element 36 for actuation of the mammal valve 8 and a control element 37 connected non-rotatably to the crankshaft 3. In order for the actuating element 36 to be better seen, the cylinder head cover 11 has been shown in this figure removed, so that the valve plate 6 is free to the outside.

The actuating element 36 has the shape of a curved rod with a round cross section. The actuating element 36 comprises a first, here straight, portion 38 which is parallel to the piston 2 translationally movable, and a second bent portion 39 which engages behind the mammal opening 7 and carries the contact portion 16, so that this also parallel to the piston 2 translational is movable. The curved section here has the shape of a semicircle. The straight contact section 16 is shorter than the straight section 38. The straight contact section 16 is aligned parallel to the direction of movement of the piston 2. The contact section 16 could also be designed as a separate component and / or have a smaller cross-section than the remaining actuating element 36. The contact portion 16 could be approximately as a resilient contact element, similar to the contact element 31 of FIGS. 1-7, executed.

When the straight portion 38 moves away from the crankpin 12, the contact portion 16 moves out of the valve plate 6. In this case, the contact portion 16 is moved away from the mammal valve 8. When the straight portion 38 moves toward the crankpin 12, the contact portion 16 can then pass through the mammal opening 7 and open the mammalian valve 8.

The actuator 36 is actuated by the control 37, a disc of variable diameter. The control element 37 could simultaneously also perform the function of a flywheel. The end of the straight portion 38 protrudes toward the crankshaft 3 or crank pin 12 out of the cylinder housing 1. The end of the straight portion 38 is biased by a spring 40 in the direction of crank pin 12 so that it can slide along the outer circumference of the control member 37. In the angular regions of the control member 37 with a small diameter, ie in Fig. 8, the lower about 180 ° of the outer periphery of the control element 37, thus the straight portion 38 is pulled to the crank pin 12 and the contact portion 16 opens the mammal valve 8. In the angular ranges of Control member 37 with a larger diameter, so in Fig. 8, the upper approximately 180 ° of the outer periphery of the control element 37, the end of the straight portion 38 is pressed away from the crank pin 12, thereby the contact portion 16 is pushed out of the valve plate 6 (ie in Fig 8 down) and the mammal valve 8 may close.

In Fig. 9, the cut refrigerant compressor of Fig. 8 can be seen that the piston 2 is just before its top dead center, thus the compression and exhaust stroke is approaching the end. The pressure valve 10 is still open. Due to the section of the contact portion 16 is not visible here. Only the end of the straight section 38 is visible, which forms the actuating section 17, which is in operative contact with the control element 37. However, the contact portion 16 may already be in contact with the mammalian valve 8 since the beginning of the suction stroke is imminent. The straight portion 38 of the actuator 36 is passed through the cylinder housing 1, wherein the cylinder housing 1 serves as a guide for the straight portion 38. The bore of the cylinder housing 1 for the straight portion 38 is here laterally below the cylinder bore for the piston 2. Since the straight portion 38 also exits through the valve plate 6, it is possible to accommodate the bent portion 39 within a cylinder head cover 11. The cylinder head cover 11 is not shown here, but could be carried out as in Figures 4 and 5. Unlike in FIGS. 4 and 5, the cylinder head cover 11 in FIGS. 8-12 would not have to have an opening for the passage of the actuating element 15 or the contact element 16 because the actuating element 36 enters the cylinder head assembly inside the cylinder head cover 11.

In Fig. 10, slightly more than the left half of the refrigerant compressor was cut parallel to the drawing plane. The sectional view along line A-A is shown in perspective in FIG. 11. Fig. 12 shows a perspective view of the uncut refrigerant compressor. Here again it is visible that in this embodiment, the straight portion 38 is slightly lower than the contact portion 16. Also here is the guide surface 24 as a peripheral surface of the control 37 recognizable.

REFERENCE LIST 1 Cylinder housing 2 Piston 3 Crankshaft 4 Longitudinal axis of crankshaft 3 5 Cylinder head assembly 6 Valve plate 7 Suction port 8 Suction valve 9 Pressure port 10 Pressure valve 11 Cylinder head cover 12 Crank pin 13 Connecting rod 14 Actuator 15 Actuator 16 Contact portion of actuator 15 17 Actuator portion 15 18 Lever body 19 first lever arm the main body 18 20 second lever arm of the main body 18 21 pivot axis of the actuating element 15 22 kink 22a first kink 22b second kink 22c third kink 23 control 24 guide surface of the control 23 25 first end face of the control element 23 26 second end face of the control element 23 27 groove 28 opening 29 bracket 30 bearing point 31 contact element 32 connecting portion of the contact element 31 33 suction muffler 34 outlet of the suction muffler 33 35 bore 36 actuator 37 control 38 straight section t of the actuator 36 39 bent portion of the actuator 36 40 spring 41 pressure muffler

Claims (24)

claims 1. Refrigerant compressor with an electric drive unit, a cylinder housing (1), a drivable by the electric drive unit crankshaft (3) and one of the crankshaft (3) drivable, in a working volume of the cylinder housing (1) guided piston (2) for cyclic compression a refrigerant which can be conveyed into the working volume via a mammal valve comprising a mammalian opening (7) and a valve closure element (8) which cyclically closes the mammal opening (7), preferably a valve spring, characterized in that an actuating device (14) is provided, with which the valve closure element (8) can be opened intermittently in each suction cycle of a working cycle, wherein a working cycle corresponds to one revolution of the crankshaft (3). 2. Refrigerant compressor according to claim 1, characterized in that the valve closure element (8) by the actuating device (14) is only supportable openable. 3. refrigerant compressor according to claim 1 or 2, characterized in that the actuating device (14) has a contact portion (16) which is in engagement with the valve closure element (8) or can be brought into engagement, wherein the valve closure element (8) by moving the Contact section (16) can be opened intermittently in each suction cycle of a duty cycle. 4. refrigerant compressor according to claim 3, characterized in that the contact portion (16) with the piston (2) facing away from the valve closure element (8) is in contact or can be brought to open this by exerting a compressive force. 5. refrigerant compressor according to one of claims 1 to 4, characterized in that the opening of the valve closure element (8) with the actuating device (14) at an equilibrium of the refrigerant pressure on both sides of the valve closure element (8) can be introduced. 6. Refrigerant compressor according to one of claims 1 to 5, characterized in that by means of the actuating device (14), the valve closure element (8) is intermittently closable in each suction cycle of a working cycle. 7. Refrigerant compressor according to one of claims 1 to 6, characterized in that the valve closure element (8) in response to a crank angle of the crankshaft (3) in cycles in each suction cycle of a working cycle can be opened. 8. Refrigerant compressor according to one of claims 3 to 7, characterized in that the actuating device (14) is mechanically coupled to the crankshaft (3) and outside of the working volume comprises an actuating element (15, 36) having one with the valve closure element (8). Having brought into contact or in contact contact portion (16). 9. refrigerant compressor according to claim 8, characterized in that the actuating element (15) is articulated on the cylinder housing (1) or on a cylinder head cover (11) of a cylinder head assembly (5) is connected. 10. Refrigerant compressor according to one of claims 8 or 9, characterized in that the actuating element (15) about a parallel to the longitudinal axis (4) of the crankshaft (3) aligned pivot axis (21) is pivotally mounted. 11. Refrigerant compressor according to one of claims 8-10, characterized in that the actuating device (14) with an actuating portion (17) of the actuating element (15, 36) standing in operative contact control element (23, 37), which control (23, 37) rotatably connected to the crankshaft (3), said actuating element (15, 36) and control element (23, 37) are designed such that a rotational movement of the crankshaft (3) in a pivoting movement or a translational movement of at least the contact portion ( 16) of the actuating element (15, 36) is convertible. 12. A refrigerant compressor according to claim 11, characterized in that the control element (23, 27) with the actuating portion (17) of the actuating element (15, 36) in contact standing guide surface (24), wherein the guide surface (24) eccentric to the longitudinal axis (4) of the crankshaft (3) is formed. 13. The refrigerant compressor according to claim 12, characterized in that the guide surface (24) of a on one of the drive unit facing (25) or one of the drive unit facing away from the end face (26) of the control element (23) arranged annularly extending groove (27) is formed , 14. The refrigeration compressor according to one of claims 12 to 13, characterized in that the actuating element (15) has a lever-shaped base body (18), wherein a first lever arm (19) of the base body (18) has the actuating portion (17) and a second Lever arm (20) of the base body (18) has the contact portion (16). 15. Refrigerated compressor according to one of claims 9 to 14, characterized in that the cylinder head cover (11) of the cylinder head assembly (5) forms a bearing point (30) for the actuating element (15) or that a holder (29) on the cylinder head cover (11). the cylinder head assembly (5) is fixed, which holder (29) forms a bearing point (30) for the actuating element (15). 16. A refrigerated compressor according to one of claims 14 or 15, characterized in that the base body (18) of the actuating element (15) at least one kink (22,22a, 22b, 22c), preferably at least one kink (22) per lever arm (19 , 20), wherein a bending axis (37) is aligned in each case substantially parallel to the longitudinal axis (4) of the crankshaft (3). A refrigeration compressor according to any one of claims 3 to 16, characterized in that a cross-sectional area of the contact portion (16) of the operating member (15, 36) is small with respect to a cross-sectional area of the mammalian opening (7). 18. Refrigerant compressor according to one of claims 3 to claim 17, characterized in that the contact portion (16) by a resilient contact element (31), in particular spring wire or plastic, is formed. 19. A refrigerant compressor according to claim 18 and one of claims 8 to 17, characterized in that the contact element (31) is planar and has a bent connecting portion (32), wherein the connecting portion (32) optionally one, preferably lever-shaped, base body (18 ) of the actuating element (15) with the contact portion (16) connects. 20. A refrigerant compressor according to claim 19, characterized in that the contact portion (16) is arranged to extend substantially parallel to a bore axis of the mammal opening (7) and that the connecting portion (32) has at least one V-shaped bend, one of the contact element (16). 31) formed plane is preferably aligned parallel to the longitudinal axis (4) of the crankshaft (3). 21. Refrigerant compressor according to one of claims 3 to 20, characterized in that the contact portion (16) at least partially in a bore (35) of the cylinder head cover (11) of the cylinder head assembly (5) and / or in a bore (35) of a suction muffler ( 33), preferably an outlet (34) of the suction muffler (33) is guided. 22. Refrigerant compressor according to one of claims 8, 11, 12, 17-20, characterized in that the actuating element (15) comprises a first, in particular straight, portion which is translationally movable parallel to the piston (2), and a second curved Section which engages behind the mammal opening (7) and carries the contact portion (16) so that it is also translationally movable parallel to the piston (2). 23. A method for operating a refrigerant compressor with an electric drive unit, a cylinder housing (1), a driven by the electric drive unit crankshaft (3) and one of the crankshaft (3) drivable, in a working volume of the cylinder housing (1) guided piston (2 ) for cyclically compressing a refrigerant, which is conveyed into the working volume via a mammalian valve comprising a mammalian opening (7) and a valve closure element (8), preferably a valve spring, which cyclically closes the mammal opening (7), characterized in that an actuating device (14 ) is provided, with which the valve closure element (8) is opened at least supportive cyclically in each suction cycle of a working cycle, wherein a duty cycle corresponds to one revolution of the crankshaft (3). 24. The method according to claim 23, characterized in that the actuating device (14) has a contact portion (16) which is in engagement with the valve closure element (8) or can be brought into engagement, wherein the valve closure element (8) by moving the contact portion (16). 16) is opened intermittently in each suction cycle of a working cycle.