CN216812061U - Discharge muffler of enclosed refrigerant compressor and enclosed refrigerant compressor - Google Patents

Abstract

The present invention relates to a discharge muffler for a hermetic refrigerant compressor, comprising: an inlet section formed by a discharge connector head, the discharge connector head defining a first discharge muffler volume; a discharge muffler shell enclosing an inner shell volume; and an outlet section, wherein the inner shell volume is divided by a partition into a second and a third discharge muffler volume; wherein the first and second discharge muffler volumes are connected by an inlet pipe; wherein the second and third discharge muffler volumes are connected by a tubular connecting passage formed by the partition, and the outlet section is connected to the third discharge muffler volume. In order to provide a discharge muffler with a compact design which can control the discharge pulsations in an efficient manner, it is proposed that the second discharge muffler volume has a first group of a plurality of first chambers and the third discharge muffler volume has a second group of a plurality of second chambers. The utility model also relates to an encapsulated refrigerant compressor.

Description

Discharge muffler of enclosed refrigerant compressor and enclosed refrigerant compressor

Technical Field

The utility model relates to a discharge muffler for an enclosed refrigerant compressor, comprising

-an inlet section formed by a discharge connector head for connecting the discharge muffler to a discharge valve of a cylinder head assembly of the refrigerant compressor to allow compressed refrigerant from a cylinder of the refrigerant compressor to enter the discharge muffler, the discharge connector head defining a first discharge muffler volume,

-a discharge muffler shell enclosing an inner shell volume, wherein the discharge muffler shell is made of a plastic material, wherein the discharge muffler shell has a lower shell part and an upper shell part, wherein the upper shell part and the lower shell part are welded together,

-an outlet section allowing the compressed refrigerant to flow out from the inner shell volume of the discharge muffler towards a discharge conduit of the refrigerant compressor, wherein the discharge connector head is located on the upper shell portion and the outlet section is located on the lower shell portion;

wherein the inner shell volume is divided into a second discharge muffler volume and a third discharge muffler volume by a partition;

wherein the first and second discharge muffler volumes are connected by an inlet pipe, wherein the second and third discharge muffler volumes are connected by a tubular connecting passage formed by the separating means, and wherein the outlet section is connected to the third discharge muffler volume.

Background

Encapsulated, in particular sealed, refrigerant compressors have long been known and are used primarily in refrigerated cabinets, such as refrigerators or refrigerated shelves, but also in mobile devices. Refrigeration processes have therefore also been known for a long time. The refrigerant is thereby heated by absorbing energy from the space to be cooled in the evaporator and is eventually superheated and boosted to a higher pressure level using a refrigerant compressor having a cylinder and a reciprocating piston. At this higher pressure level, the refrigerant is cooled via the condenser and sent back into the evaporator via a throttle valve, via which the pressure is reduced and the refrigerant is further cooled before the cycle is restarted.

The path of the (normally gaseous) refrigerant through the compressor can be described as follows:

the refrigerant enters a compressor housing of the refrigerant compressor, which encloses a pump unit of the refrigerant compressor, via a suction line which is connected in the operating state to an evaporator of the refrigerating device. During the suction cycle, the refrigerant is sucked into the cylinder of the pump unit of the refrigerant compressor through the suction muffler, the suction opening of the valve plate, which is released by the suction valve spring. The suction is caused by the linear movement of the piston within the cylinder. During the compression portion of the compression and discharge cycle, the refrigerant is compressed within the cylinder by the linear motion of the piston until the discharge valve spring releases the discharge opening of the valve plate. During the discharge portion of the compression and discharge cycle, the refrigerant thus compressed then flows into the discharge muffler through the discharge opening of the valve plate and leaves the compressor shell through a discharge conduit connected to the discharge muffler by a discharge connection pipe. The discharge pipe is connected in the operating state to a condenser of the refrigerating device.

The pump unit includes: a crankshaft system including a piston and causing linear motion of the piston within a cylinder; a crankcase, in which a crankshaft of the crankshaft system is mounted, the crankcase further having a cylinder housing; an electric drive unit including a rotor and a stator; and a cylinder head assembly. The cylinder head assembly includes a valve plate, a suction valve spring, a discharge valve spring, a suction muffler and a discharge muffler. The pump unit is supported within the compressor housing on a plurality of support spring assemblies, preferably four support spring assemblies.

The housing typically includes a lower housing portion and an upper housing portion welded together. The discharge and suction pipes and the service pipe (also called service pipe) are sealingly connected to the housing. Since the refrigerant compressor is a separate product that is integrated into the refrigeration device at some stage of the assembly process, the discharge conduit, the suction conduit and the service conduit are also referred to as discharge connector, suction connector and service connector, since they are configured to be connected with the corresponding elements of the refrigeration device during assembly and/or in an operating state.

The motion of the piston is caused by the rotation of the crankshaft, wherein the piston is connected to a crank pin of the crankshaft via a connecting rod. An electric drive unit is required to facilitate rotation of the crankshaft to which the rotor is secured.

Generally, the electronic control unit is mounted to an outer surface of the compressor housing, wherein the stator is connected to an electric pass-through element (also referred to as "fuse") via an internal harness, and the electronic control unit is connected to the electric pass-through element via an external harness. The electronic control unit supplies power to the stator and thereby controls the rotational speed of the pump unit of the refrigerant compressor.

SUMMERY OF THE UTILITY MODEL

It is an object of the utility model to provide a discharge muffler with a compact design, with which the discharge pulsations can be controlled in an efficient manner. It is a further object of the present invention to provide an optimized muffler design to increase the overall efficiency of the refrigerant compressor.

In order to achieve at least one of the above objects in the discharge muffler as initially defined, it is proposed according to the utility model that the second discharge muffler volume has a first group of a plurality of first chambers and the third discharge muffler volume has a second group of a plurality of second chambers.

Due to this special design of the discharge muffler, the pulsation caused by the refrigerant flowing through the discharge muffler during the discharge cycle of the pump unit of the refrigerant compressor can be controlled by the following principle: the discharge muffler is divided into three discharge muffler volumes, which are fluidly connected in series by two pipes. The first discharge muffler volume defined by the discharge connector head is connected to the second discharge muffler volume by a first pipe, i.e. by an inlet pipe. The muffler shell encloses an internal muffler volume that is further divided by a dividing means into a second discharge muffler volume and a third discharge muffler volume. The second and third discharge muffler volumes are interconnected by a second pipe, i.e. a tubular connecting passage formed by the partition. The refrigerant exits the discharge muffler shell from the third discharge muffler volume through the outlet section.

While the overall structure of the refrigerant flow path is defined by the elements described above, the discharge pulsations can be further reduced by further dividing the second and third discharge muffler volumes into smaller chambers that act as additional pulsation filters. Thus, the second discharge muffler volume is divided into at least two first chambers forming a first group of first chambers, and the third discharge muffler volume is divided into at least two second chambers forming a second group of multiple second chambers. It is envisioned that the number of first chambers may be less than, greater than, or equal to the number of second chambers.

According to a variant of yet another embodiment of the utility model, the upper housing part comprises a plurality of chamber walls extending towards the lower housing part, wherein each of the first chambers and each of the second chambers is delimited by at least one chamber wall. Preferably, the upper housing part of the discharge muffler encloses a larger part of the inner housing volume of the muffler housing. During operation of the refrigerant compressor, the main refrigerant flow is directed by the inlet pipe to the lower housing portion of the discharge muffler, while the upper housing portion is responsible for additional pulsation filtering. Thus, the chamber wall defining the first and second chambers is part of the upper housing part. Since on the one hand the separating means, preferably the upper separating wall, also serves as a boundary for the adjacent first chamber as well as the adjacent second chamber, and on the other hand the inner surface of the upper housing part serves as a boundary surface, the chamber wall does not serve as the sole boundary for the chambers. The connection of the upper and lower housing parts by welding ensures a substantially leak-proof connection. Preferably, the lower housing portion is made of a material that allows light of a particular wavelength to pass through to facilitate laser welding of the exhaust muffler housing. For example, the lower housing portion may be at least partially, preferably uniformly, transparent.

In order to further improve the flow characteristics of the refrigerant flow and further improve the pulsation filtering, a further embodiment variant of the utility model proposes that each chamber wall has an end section facing the lower housing part and that each end section has an arc-shaped opening. By improving the pulsation filtering, the pulsation of the refrigerant is reduced.

Since the discharge muffler is part of the high pressure side of the gas line of the refrigerant compressor, it is subject to increased structural loads and stresses. In addition, the compression process increases the temperature of the compressed refrigerant, which also causes the temperature of the discharge muffler to increase during operation. In order to reduce the overall size of the discharge muffler despite these loads, a further internal reinforcement is provided in a further embodiment variant of the discharge muffler, which proposes that the upper housing part comprises reinforcing ribs extending transversely to the chamber wall. The reinforcing ribs reinforce the external strength of the upper housing and the internal strength of the chamber wall.

According to a further embodiment variant of the utility model it is proposed that the first group of a plurality of first chambers comprises at least two first chambers and the second group of a plurality of second chambers comprises at least three second chambers, preferably at least four chambers. A preferred embodiment has two first chambers and five second chambers. This design provides a preferred combination of chamber numbers relative to the reduced size of the discharge muffler shell.

In a further embodiment variant of the utility model, the separating means comprise:

an upper partition wall in the upper housing part, which upper partition wall has an end section which projects into the lower housing part, and

a lower partition wall in the lower housing part, which lower partition wall has an end section which projects into the upper housing part,

wherein the tubular connecting passage is formed between overlapping sections of the upper and lower partition walls. Due to this particular design of the partition means, the refrigerant flow from the inlet pipe is redirected into the first chamber by the respective portions of the upper and lower partition walls. This redirection is improved by the upper partition wall projecting into the lower housing part and the lower partition wall projecting into the upper housing part. Only after the pulsation filtering in the first chamber, the major part of the refrigerant flow is directed through the tubular passage into the third discharge muffler volume. Preferably, the upper partition wall is arranged closer to the inlet section and the lower partition wall is arranged closer to the outlet section than the respective other partition wall.

In order to define the tubular passage between the second and third discharge muffler volumes with a simple design, a further embodiment variant of the utility model proposes that at least a part of the lower partition wall has a substantially U-shaped cross section. Preferably, the U-shaped section of the lower partition wall overlaps the substantially flat surface of the upper partition wall to form a substantially vertical tubular passage. Further, it is preferable that the lower partition wall extends in the height direction.

In order to connect the discharge muffler with a discharge duct of the refrigerant compressor, which discharge duct is connected to the high-pressure side of the refrigeration device in the operating state of the refrigerant compressor, a further embodiment variant of the utility model proposes that the discharge muffler further comprises a discharge connecting tube having a first end section connected to the outlet section and a second end section for connection with the discharge duct of the refrigerant compressor, wherein the discharge connecting tube is made of a plastic material. Since the discharge connection pipe connects the discharge muffler attached to the pump unit as part of the cylinder head assembly with the discharge duct fixed to the compressor housing, the discharge connection pipe must be flexible or bendable to compensate for relative movement from the pump unit supported in the compressor housing using the support spring assembly with respect to the compressor housing. The discharge connection pipe is therefore made of a plastic (in other words, polymer) material, which both reduces the weight and ensures the required flexibility.

A further preferred embodiment variant of the utility model proposes that the discharge connection tube is made of a polyamide PA-based polymer material. While other polymeric materials having the same material properties can be used to make suction mufflers, polyamide-based polymeric material products have been tested with an excellent combination of availability, cost, thermal properties (especially thermal conductivity), and mechanical properties.

The connection of the discharge connection pipe to the discharge muffler housing, in particular to the lower housing part, can be achieved in a further preferred embodiment variant which proposes that the outlet section of the discharge muffler comprises a tubular discharge connection extension which projects from the outer surface of the lower housing part, wherein the first end section of the discharge connection pipe is inserted into the tubular extension. Since both the discharge muffler shell and the discharge connecting pipe are made of a plastic material, the connection can be further strengthened by plastic welding. The plastic welding also ensures that the connection between the discharge muffler shell and the discharge connection pipe is sealed.

In order to seal the connection between the discharge connection pipe and the discharge duct of the refrigerant compressor, a further embodiment variant of the utility model proposes that the second end section of the discharge connection pipe is inserted into a connection sleeve having a groove for receiving an O-ring seal. In an operating state of the refrigerant compressor, the connecting sleeve is inserted into the discharge duct and the O-ring seals a space between an outer circumferential surface of the connecting sleeve and an inner surface of the discharge duct. Preferably, the connecting sleeve is also made of a plastic material, so that it can be plastic welded to the discharge connecting tube. Furthermore, once the connection sleeve is inserted, the discharge conduit may be crimped in order to hold the connection sleeve in place and prevent the connection sleeve from slipping out of the discharge conduit during operation.

In order to establish a tightly sealed connection between the discharge side of the valve plate, in particular with respect to its discharge opening, and the discharge connector head, a further embodiment variant of the utility model proposes that the discharge connector head has a sealing face for connection with a valve plate of a refrigerant compressor, which valve plate has a circumferential groove for receiving the first sealing element. By improving the seal between the discharge connector head and the valve plate, the overall coefficient of performance [ COP ] of the refrigerant compressor may be increased because losses in the discharge line are minimized.

During a discharge cycle, when the pressure in the cylinder reaches a certain threshold value, a discharge valve spring, which is usually configured as a reed valve, opens the discharge valve by elastic deformation. When below the threshold, the discharge valve spring elastically returns to the initial state of closing. To ensure that the discharge valve spring is closed at the beginning of the suction cycle, it must be avoided that the discharge valve spring "opens excessively", otherwise it would take too long to return to the initial state. A further embodiment variant of the utility model therefore envisages the discharge connector head having a projecting element which serves as a stop element for the discharge valve spring of the discharge valve. Once the discharge valve spring is in contact with the protruding element, the deformation is interrupted and further deformation can be prevented to avoid over-opening. Since the stop element is integrated in the discharge connector head, no separate element is required and the overall size of the cylinder head assembly can be reduced.

A further embodiment variant of the utility model envisages that the discharge muffler, in particular the discharge connector head and/or the discharge muffler shell, is made of a polyamide-based polymer material. Although other polymeric materials having the same material properties can be used to manufacture the suction muffler, products of polyamide-based polymeric materials have been tested with an excellent combination of availability, cost, thermal properties (especially thermal conductivity) and mechanical properties. Furthermore, the discharge muffler housing, including the discharge connector head, is usually produced via injection molding. Generally, the lower housing portion of the discharge muffler, the upper housing portion of the discharge muffler, and the discharge connector head portion integrally formed with the upper housing portion are made of a polyamide-based polymer material.

In a further preferred embodiment variant of the discharge muffler, the polymer material is fiber-reinforced, preferably reinforced with glass fibers. The fiber-reinforced polymer material has further improved properties, in particular with regard to mechanical stability. Preferably, the polymer material used is PA66 GF30, which has a glass fiber content of 30% and is available from enssinger under the trade name TECAMID 66GF 30. Typically, the lower housing part of the discharge muffler, the upper housing part of the discharge muffler and the discharge connector head are made of a fiber-reinforced polymer material, preferably a reinforced polyamide-based polymer material.

The utility model also relates to an encapsulated refrigerant compressor having

-a compressor housing having a lower housing part and an upper housing part, wherein a discharge duct, a suction duct and a service duct enter the compressor housing, wherein an electrical pass-through element is inserted into the compressor housing;

-a pump unit comprising:

-a crankshaft system with a crankshaft, a crankpin, a connecting rod and a piston;

-an electric drive unit having an internal wiring harness, a stator and a rotor, said rotor being fixed to said crankshaft, wherein said internal wiring harness connects said electric pass-through element and said stator;

-a crankcase with a cylinder housing, wherein a cylinder for the reciprocating movement of the piston is located in the cylinder housing, wherein the crankshaft is rotatably mounted in the crankcase, wherein the stator is attached to the crankcase;

-a cylinder head assembly mounted to a cylinder housing of the crankcase, the cylinder head assembly comprising a valve plate, a suction valve spring, a discharge valve spring and a suction muffler;

-a plurality of support spring assemblies for supporting the compressor body/pump unit in the compressor housing,

wherein the cylinder head assembly comprises a discharge muffler according to the utility model as described above, wherein the discharge muffler has a discharge connection pipe connected to a discharge duct, preferably as described in more detail above.

Drawings

The utility model will be explained in more detail below with reference to an exemplary embodiment. The drawings are provided by way of example and are intended to explain the concepts of the utility model but in no way should the utility model be limited or even ultimately presented, in which:

figure 1 shows a three-dimensional view of a refrigerant compressor from the outside;

FIG. 2 shows an exploded view of the refrigerant compressor;

fig. 3 shows a three-dimensional view of an assembled pump unit of the refrigerant compressor;

FIG. 4 shows an exploded view of the exhaust muffler and the elements of the cylinder head assembly;

FIG. 5 shows a perspective view of the discharge muffler;

FIG. 6 shows a bottom view of the upper housing portion of the discharge muffler;

FIG. 7 shows a three-dimensional view of the lower housing portion of the discharge muffler;

fig. 8 shows a schematic cross-sectional view of the discharge muffler according to fig. 5;

fig. 9 shows a sectional view of the discharge muffler according to fig. 5.

Detailed Description

Fig. 1 shows an external view of a, in particular sealed, encapsulated refrigerant compressor 1 extending in a length direction x, a width direction y and a height direction z. The length direction x, width direction y and height direction z form an orthogonal reference frame. Generally, the refrigerant compressor has a length dimension measured along the length direction x that is greater than a width dimension measured along the width direction y.

In the following, occasional reference will be made to the (normally gaseous) refrigerant flowing through the refrigerant compressor 1. It goes without saying that these comments refer to the operating state of the refrigerant compressor 1, but that no refrigerant is usually present in the refrigerant compressor 1 when the refrigerant compressor 1 is produced or sold as a separate product.

The refrigerant compressor 1 includes a compressor housing 100, and in the present embodiment, the compressor housing 100 is composed of a lower housing part 110 and an upper housing part 120. The upper and lower housing portions 120, 110 are welded together. The support base plate 160 is fixed to the compressor housing 100 at both sides of the lower housing portion 110 extending mainly in the length direction x. Each support base plate 160 has two openings 164 (see fig. 2) for mounting the support damper assembly 90.

The suction duct 30, which can be connected to the low-pressure side of the refrigeration device, enters the upper shell part 120 at the side of the refrigerant compressor 1. During operation, refrigerant is drawn into the refrigerant compressor 1 via the suction line 30, mainly during a suction cycle of the pump unit 10 (see fig. 3) of the refrigerant compressor 1. In the operating state, the suction line 30 is therefore connected directly or indirectly, for example via a line on the low-pressure side of the refrigerating device, to the evaporator of the refrigerating device. With regard to the compressor housing 100, the suction duct 30 enters the upper housing part 110 via the second connector element 80, which second connector element 80 is connected sealingly, for example by welding and/or soldering, on the one hand with the upper housing part 120 and on the other hand to the suction duct 30.

The discharge duct 20 and the maintenance duct 40 enter the lower casing 110 at the front side of the refrigerant compressor 1. The discharge duct 20 enters the lower housing part 110 via a first connector element 70, which first connector element 70 is sealingly connected, for example by welding and/or soldering, on the one hand with the lower housing part 110 and, on the other hand, with the discharge duct 20 or the service duct 40. During operation, refrigerant compressed by the pump unit 10 can flow out of the refrigerant compressor 1 through the discharge conduit 20, primarily during the compression and discharge cycle of the pump unit 10. Thus, the discharge conduit 20 may be connected to the high pressure side of the refrigeration device to allow compressed refrigerant to be supplied to the high pressure side of the refrigeration device. In the operating state, the discharge line 20 is connected directly or indirectly, for example via a line on the high-pressure side of the refrigerating device, to the condenser of the refrigerating device.

The service conduit 40 may be used to inject lubrication oil and/or refrigerant into the refrigerant compressor 1 during an assembly refrigerant application or during a service operation. Similar to the suction duct 30, the service duct 40 is connected to the lower housing part 110 by means of a second connector element 80, which is sealingly connected on the one hand with the lower housing part 110 and on the other hand with the service duct 40, for example by welding and/or soldering.

With reference to fig. 2, all the main components of the refrigerant compressor 1 and their functions will be briefly described. The refrigerant compressor 1 includes a casing 100, an electronic control unit 800 detachably mounted to the compressor casing 100, and a pump unit 10 (see fig. 3) located inside the compressor casing 100 and supported by four support spring assemblies 60. The refrigerant compressor 1 is mounted on four supporting damper assemblies 90, which are connected to respective openings of two supporting base plates 160. Each support damper assembly 90 includes a damper pin 92, an outer damping element 91, a liner disk 93, and a fixed element 94.

As can be seen in fig. 2, the suction duct 30 enters the upper housing part 120 via the second connection opening 102, while the service duct 20 enters the lower housing part 110 via the third connection opening 103. Although not visible in fig. 2, the discharge duct 20 enters the lower housing part 110 through the first connection opening 101.

The pump unit 10 includes an electric drive unit 400, a crankshaft system 200, a crankcase 300, and a cylinder head assembly 500, the cylinder head assembly 500 including a suction muffler 600 and a discharge muffler 700.

Each support spring assembly 60 includes a mounting pin 140 fixed (preferably welded) to the lower housing portion 110, a lower spring pin 61 mounted on the respective mounting pin 140, and a support spring 62 supported on the lower spring pin 61.

The electric drive unit 400 includes a stator 420, a rotor 410, and an internal wiring harness 430. The stator 420 has a lower end element 421 made of plastic, which lower end element 421 comprises four upper spring seats 63 for the respective supporting springs 62. The stator 420 is fixed to the crankcase 300 via two stator mounting screws 340. The internal harness 430 connects the stator 420 with the electric pass-through element 50 located in the compressor housing 100. The electronic control unit 800 is connected to the electric pass element 50 via an external harness 801 outside the compressor 1 to control the rotation speed of the pump unit 10.

The crankshaft system 200 comprises a piston 240 and a crankshaft 210, the crankshaft 210 being rotatably mounted in main bearings 302 of the crankcase 300 on the one hand and being axially supported on the crankcase 300 by means of ball bearings 201 on the other hand. The crankshaft 210 has a crank pin 220 on which a connecting rod 230 is mounted, the connecting rod 230 connecting the crank pin 220 with a piston pin 243 of a piston 240. The piston pin 243 is fixed to the piston 240 via a ferrule 244, the ferrule 244 being inserted into mating axial openings in the piston 240 and the piston pin 243. On the lower end of the crankshaft 210 opposite to the end having the crank pin 220, the rotor 410 is preferably mounted to the crankshaft 210 via press fitting. Further, an oil absorber 250 for delivering lubricant from a lubricant oil sump formed in the lower housing portion 110 to a lubricant delivery system of the crankshaft system 200 during operation is mounted to the rotor 410 via three mounting rivets 251.

The crankcase 300 includes a cylinder housing 310, and a cylinder 320 is formed in the cylinder housing 310. The piston 240 reciprocates within the cylinder 320 during operation of the refrigerant compressor 1 to draw refrigerant into the cylinder 320 during a suction cycle and compress and discharge the compressed refrigerant during compression and discharge cycles. On the crankcase 300, a set of two first protrusions 301 is located on the side opposite to the cylinder housing 310, and a set of two second protrusions 311 is located on the cylinder housing 310 itself. Attached to each of the first and second protrusions 301, 311 is an inner damping element 330, which inner damping element 330 interacts with a respective area of the inner surface of the upper housing part 120, in order to dampen vibrations of the pump unit 10 during operation and to prevent damage during transport.

To establish a suction path and a discharge path for refrigerant from the suction pipe 30 to the discharge pipe 20 via the cylinder 320, the cylinder head assembly 500 is mounted to a cylinder head section of the cylinder housing 310. The cylinder head assembly 500 includes a cylinder gasket 510, a suction valve spring 520, a valve plate 530, and a discharge valve spring 540, wherein the valve plate 530 has a suction opening and a discharge opening. The cylinder gasket 510 and the suction valve spring 520 are located at a suction side of the valve plate 530, which faces the piston 240. The discharge valve spring 540 is located at the discharge side of the valve plate 530, which faces the opposite direction of the piston 240. When assembled, the valve plate 530, the suction valve spring 520, and the cylinder gasket 510 are pressed into the valve plate seat 312 of the cylinder housing 310, as will be described in detail below.

The suction connector head 640 of the suction muffler 600 and the discharge connector head 730 of the discharge muffler 700 are pressed to the discharge side of the valve plate 530, with the first sealing member 550 being placed between the valve plate 530 and the suction connector head 640 and the discharge connector head 730.

During a suction cycle of the pump unit 10, the piston 240 within the cylinder 320 moves away from the valve plate 530, thereby establishing negative pressure within the cylinder 320, because the suction valve spring 520 keeps the suction opening of the valve plate 530 closed due to its elastic force, while the discharge valve spring 540 closes the discharge opening of the valve plate 530. When the negative pressure exceeds a certain threshold, the suction valve spring 520, which has at least a section configured as a reed valve, opens the suction opening to allow the refrigerant to flow from the suction pipe 30 into the cylinder 320 through the suction muffler 600.

During the compression cycle of pump unit 10, piston 240 within cylinder 320 moves in the direction of valve plate 530, so that the refrigerant in cylinder 320 is compressed, because discharge valve spring 540 keeps the discharge opening of valve plate 530 closed due to its elastic force, while suction valve spring 520 keeps the suction opening of valve plate 530 closed. Once the pressure of the compressed refrigerant exceeds a predetermined threshold, the discharge valve spring 540, which is configured as a reed valve, opens the discharge opening of the valve plate 530 to allow the refrigerant to flow from the cylinder 320 to the discharge pipe 20 through the discharge muffler 700.

The suction muffler 600 includes a lower housing portion 610, an upper housing portion 620, and an inner housing element 630, and the inner housing element 630 is inserted into a suction muffler volume defined by the lower housing portion 610 and the upper housing portion 620 of the suction muffler 600. The refrigerant is sucked into the suction muffler 600 mainly during a suction cycle of the pump unit 10 through the inlet opening 621 in the upper housing portion 620. The suction muffler 600 attenuates sound when refrigerant flows through it based on the well-known helmholtz principle, i.e., by forming a chamber inside the suction muffler 600 that serves as a resonator absorbing sound. The refrigerant flows out of the suction muffler 600 through the suction connector head 640, and the suction connector head 640 is placed above the suction opening of the valve plate 530 and on the upper housing portion 620 of the suction muffler 600.

The discharge muffler 700 includes a lower housing part 710, an upper housing part 720, and a discharge connector head 730 connected to the upper housing part 720 of the discharge muffler 700. During the discharge cycle of pump unit 10, compressed refrigerant from the discharge opening of valve plate 530 enters discharge muffler 700 through discharge connector head 730. Discharge muffler 700 attenuates sound as refrigerant flows through it based on the well-known helmholtz principle, i.e., by a chamber formed within discharge muffler 700 that acts as a resonator to absorb sound and/or by pulsating filtering. The compressed refrigerant flows out of the discharge muffler 700 through the discharge connection pipe 750, and the discharge connection pipe 750 is connected to the discharge pipe 20 via the connection sleeve 760 and the O-ring.

A mounting assembly 580 (see fig. 3) facilitates mounting of the cylinder head assembly 500 to the cylinder housing 310, the mounting assembly 580 including a clamping element 560 for clamping the valve plate 530 to the valve plate seat 312 and a fixing element 570 for pressing the suction connector head 640 and the discharge connector head 730 against the valve plate 530. The fixing element 570 is snapped onto the clamping element 560. The clamping element 560 further includes two locating pins 565 (see fig. 2) for respectively aligning the discharge connector head 730 with the discharge opening and the suction connector head 640 with the suction opening.

Fig. 3 shows the pump unit 10 of the refrigerant compressor 1 in an assembled state. The suction muffler 600 and the discharge muffler 700 are fixed to the cylinder housing 310 via the clamping member 560 and the fixing member 570 of the mounting assembly 580, while the crankshaft 210 is inserted into the crankcase 300 and the stator 420 surrounds the rotor 410.

Fig. 4 shows a schematic exploded view of an embodiment of a discharge muffler 700 according to the present invention from an angled side view, wherein also the other main components of the cylinder head assembly 500 for connecting the discharge muffler 700 with the cylinder housing 310 are presented. The discharge muffler 700 includes a discharge muffler shell 706 enclosing an inner shell volume 707, wherein the discharge muffler shell 706 has a lower shell portion 710 and an upper shell portion 720, the lower shell portion 710 having an inner surface 710a and an outer surface 710b, and the upper shell portion 720 having an inner surface 720a and an outer surface 720b (see fig. 6 and 7). The lower housing portion 710 and the upper housing portion 720 are welded together.

Further, the discharge muffler 700 comprises an outlet section 705 to allow compressed refrigerant to flow out from the inner shell volume 707 towards the discharge conduit 20, the outlet section 705 being located on the lower shell portion 710. The outlet section 705 includes a tubular discharge connection extension 712 that protrudes from the outer surface 710b of the lower housing portion 710.

In this embodiment of the utility model, the discharge connection pipe 750 made of a polyamide-based polymer material has a first end section 751 for connection with the outlet section 705 of the lower housing part 710 and a second end section 752 for establishing a connection with the discharge duct 20. Specifically, the first end section 751 of the discharge connection pipe 750 is inserted into the tubular discharge connection extension 712 of the outlet section 705 of the lower housing part 710, and the second end section 752 of the discharge connection pipe 750 is inserted into the connection sleeve 760, which connection sleeve 760 is inserted into the discharge duct 20, as already described with reference to fig. 2.

When assembled, sealing surface 730a of inlet section 704, formed by discharge connector head 730 located on upper housing portion 720, is pressed against discharge side 530b of valve plate 530, which discharge side 530b faces in the opposite direction of piston 240 (see FIG. 2). The sealing face 730a has a circumferential groove 732 (see fig. 5) for receiving the first seal element 550.

First sealing element 550 is disposed between valve plate 530 and discharge connector head 730. The discharge valve spring 540 is located on the discharge side 530b of the valve plate 530. The cylinder gasket 510 and the suction valve spring 520 of the cylinder head assembly 500 are located at a suction side 530a of the valve plate 530, the suction side 530a facing the piston 240 (see fig. 2).

As can be seen in detail in fig. 4, the valve plate 530 has a suction opening 531 for allowing the refrigerant to flow from the suction muffler 600 into the cylinder 320 when the suction opening 531 is opened by the suction valve spring 520. Valve plate 530 also has discharge opening 532 for allowing the compressed refrigerant to flow from cylinder 320 to discharge tube 20 through discharge muffler 700 when discharge valve spring 540 opens discharge opening 532. The suction opening 531 may be closed by the suction reed valve section 521 of the suction valve spring 520.

The first sealing element 550 includes a first sealing section 550a and a second sealing section 550b, wherein the first sealing section 550a is substantially shaped as a flat gasket, while the second portion 550b has properties and cross-sections similar to an O-ring. The first sealing element 550 further comprises a suction opening 551 in the first sealing section 550a and a discharge opening 552 in the second sealing section 550 b. The suction opening 551 of the first seal 550 is arranged to substantially match the suction opening 531 of the valve plate 530 so that the refrigerant can pass through the first seal 550 also when the refrigerant is sucked into the cylinder 320 through the suction muffler 600. After installation, the fixing element 570 (see fig. 3) compresses the first sealing section 550a between the sealing surface 640a of the suction connector head 640 and the discharge side of the valve plate 530, so as to seal the low pressure connection between the valve plate 530 and the suction connector head 640 in the region of the suction opening 531. The second seal segment 550b is configured to be inserted into a circumferential groove of a sealing face of the drain connector head 730. Thus, the second sealing section 550b is designed to seal the high-pressure connection between the valve plate 550 and the discharge connector head 730 in the region of the discharge opening 532 when the fixing element 570 presses the discharge connector head 730 onto the valve plate 550.

The discharge connector head 730, which defines the first discharge muffler volume 701, has an opening connected to the inlet pipe 731 so that refrigerant can flow from the cylinder 320 into the discharge muffler 700 during a discharge cycle; referring to fig. 5, a three-dimensional view of the discharge muffler 700 is shown. The opening of the discharge connector head 730 and the inlet pipe 731 are sized to match the size of the discharge opening 532 of the first sealing element 550 so that the sealing face 730a of the discharge connector head 730 presses the second sealing section 550b against the valve plate 530.

As can be seen in fig. 5, the discharge connector head 730 has two second positioning openings 734, with which the discharge muffler 700 is positioned on the positioning pins 565 of the clamping element 560 when assembled (see fig. 2). Further, the discharge connector head 730 includes a protruding element 733 serving as a stopper element of the discharge valve spring 540.

In this embodiment of the utility model, both discharge connector head 730 and discharge muffler shell 706 are made of a fiber-reinforced polyamide-based polymeric material.

The inner housing volume 707 is divided by a partition 740 into a second discharge muffler volume 702 and a third discharge muffler volume 703, wherein the second discharge muffler volume 702 and the third discharge muffler volume 703 are connected by a tubular connecting passage 741, the tubular connecting passage 741 being formed by the partition 740 (see fig. 8 and 9). Fig. 8 shows a schematic sectional view of the discharge muffler 700 according to fig. 5, while fig. 9 shows a sectional view of the discharge muffler according to fig. 5, the section lines in fig. 9 extending in such a way that the last second chamber 709 visible in fig. 8 is not visible in fig. 9. In this embodiment, the second discharge muffler volume 702 has two first chambers 708, while the third muffler volume 703 has five second chambers 709.

Furthermore, fig. 8 shows the overall structure of the discharge muffler 700 and its different discharge muffler volumes 702, 703 and pipes 731, 740: a first discharge muffler volume 701 is formed within discharge connector head 730 and a second discharge muffler volume 702 is formed within muffler shell 706 and separated from third discharge muffler volume 703 by a partition 740. The first discharge muffler volume 701 is connected to the second discharge muffler volume 702 by an inlet pipe 731, while the second discharge muffler volume 702 is connected to the third discharge muffler volume 703 by a tubular connecting passage 741 formed by a partition 740.

In fig. 6, which shows a bottom view of the upper housing part 720 of the discharge muffler 700, it can be seen that the upper housing part 720 comprises a first set of a plurality of first chamber walls 721 extending in the direction of the lower housing part 710, wherein each first chamber 708 and each second chamber 709 is delimited by at least one chamber wall 721. Each chamber wall 721 has an end section 721a facing the lower housing part 710, and each end section 721a has an arc-shaped opening 724. In addition, the upper housing portion 720 includes reinforcing ribs 722 that extend transverse to the chamber wall 721.

The partition 740 includes an upper partition wall 723 in the upper housing portion 720, the upper partition wall 723 having an end section 723a (see fig. 6) that extends into the lower housing portion 710. In addition, the partition 740 includes a lower partition wall 711 in the lower housing portion 710, which is visible in FIG. 7, which shows a three-dimensional view of the lower housing portion 710 of the discharge muffler 700 in FIG. 7. The lower partition wall 711 has an end section 711a projecting into the upper housing part 720, wherein a tubular connecting passage 741 is formed between the upper partition wall 723 and the overlapping section of the lower partition wall 711, wherein the lower partition wall 711 has a substantially U-shaped cross-section. Figure 9 shows the tubular passage 741 and the partition 740 in more detail.

In addition, the lower housing portion 710 includes a plurality of centering pins 713 for centering the upper housing portion 720 on the lower housing portion 710. During assembly, the upper housing portion 720 is placed on the lower housing portion 710 in such a manner that all of the centering pins 713 are disposed on the inner surface 720a of the upper housing portion 720, thereby completely conforming the distance between the outer surface 720b of the upper housing portion 720 and the collar portion 714 of the lower housing portion 710.

Fig. 8 and 9 further depict the flow of refrigerant through the discharge muffler 700 by arrows: the refrigerant flows into the first discharge muffler volume 701 formed in the discharge connector head 730 substantially only during the discharge cycle. The refrigerant is directed from the first discharge muffler volume 701 into the second discharge muffler volume 702 via the inlet pipe 731. Within the second discharge muffler volume 702, a major portion of the refrigerant flow is deflected by the partition 740, primarily through the upper partition wall 723, into the first plurality of first chambers 708 where the refrigerant is folded back and the pulsations are thereby reduced. The refrigerant folded back from the first chamber 708 and the portion of the refrigerant flow not folded back by the partition 740 then flows through the tubular connecting passage 741 of the partition 740 into the third discharge muffler volume 703 where the major portion of the refrigerant flow is directed into a second plurality of second chambers 709 that act similarly to the first chambers 708. The refrigerant flows from third discharge muffler volume 703 through outlet section 705, specifically through pipe connection extension 725, into discharge connection pipe 750.

The lower housing portion 710 is made transparent colored to allow laser light to pass through it to weld the upper housing portion 720 and lower housing portion 710 together. Collar section 714 of lower housing portion 710 forms a ledge and allows for containment of molten material of upper housing portion 720 and/or lower housing portion 710, which facilitates a good connection.

Reference numerals

1 refrigerant compressor

10 Pump Unit

20 discharge conduit

30 suction pipe

40 service pipe

50 electric pass element

60 support spring assembly

61 lower spring pin

62 support spring

63 Upper spring seat

70 first connector element

80 second connector element

90 support damper assembly

91 external damping element

92 damper pin

93 lining disk

94 fixing element

100 compressor housing

102 second connection opening

103 third connection opening

110 lower shell part

120 upper shell part

140 mounting pin

160 support substrate

164 opening of support substrate

200 crankshaft system

201 ball bearing

210 crankshaft

220 crank pin

230 connecting rod

240 piston

243 piston pin

244 ferrule

250 oil suction device

251 setting rivet

300 crankcase

301 first projection

302 main bearing section of crankcase

310 cylinder housing

311 second projection

312 valve plate seat

320 cylinder

330 internal damping element

340 stator mounting screw

400 electric drive unit

410 rotor

420 stator

421 lower end element

430 internal harness

500 cylinder head assembly

510 cylinder gasket

520 suction valve spring

530 valve plate

530a suction side of valve plate

530b discharge side of valve plate

531 suction opening

532 discharge opening

540 discharge valve spring

550 first sealing element

550a first seal segment of a first seal element

550b second seal segment of the first seal element

551 suction opening of the first sealing element

552 discharge opening of the first sealing element

560 clamping element

565 locating pin

570 fixing element

580 installation component

600 suction muffler

601 suction muffler volume

610 lower housing portion of suction muffler

620 upper casing part of suction muffler

621 inlet opening

630 inner housing element

640 inhalation connector head

640a sealing surface of a suction connector head

700 discharge muffler

701 first discharge muffler volume

702 second discharge muffler volume

703 third discharge muffler volume

704 inlet section of discharge muffler

705 outlet section of discharge muffler

706 exhaust muffler shell

707 inner shell volume

708 first chamber

709 second Chamber

710 lower housing portion of a discharge muffler

710a inner surface of the lower housing portion

710b outer surface of the lower housing portion

711 lower partition wall

711a lower partition wall

712 tubular discharge connection extension

713 centering pin

714 collar segment

720 upper casing part of discharge muffler

720a inner surface of the upper housing part

720b outer surface of the upper housing part

721 chamber wall

721a end section of the chamber wall

Reinforcing ribs 722

723 upper partition wall

723a end section of the upper partition wall

724 arc opening

730 discharge connector head

730a discharge connector head sealing surface

731 inlet pipe

732 circumferential grooves

733 projecting element

734 second positioning opening

740 separation device

741 tubular connecting passage

750 discharge connection tube

751 discharge-connection tube first end section

752 second end section of the discharge connection tube

760 coupling sleeve

761 groove of the connecting sleeve

762O type sealing ring

800 electronic control unit

x length direction

y width direction

z direction of height

Claims (16)

1. A discharge muffler (700) for a packaged refrigerant compressor (1), the discharge muffler (700) comprising:

-an inlet section (704) formed by a discharge connector head (730) for connecting the discharge muffler (700) to a discharge valve of a cylinder head assembly (500) of the encapsulated refrigerant compressor (1) to allow compressed refrigerant from a cylinder (320) of the encapsulated refrigerant compressor (1) to enter the discharge muffler (700), the discharge connector head (730) defining a first discharge muffler volume (701),

-a discharge muffler shell (706) enclosing an inner shell volume (707), wherein the discharge muffler shell (706) is made of a plastic material, wherein the discharge muffler shell (706) has a lower shell part (710) and an upper shell part (720), wherein the upper shell part (720) and the lower shell part (710) are welded together,

-an outlet section (705), the outlet section (705) allowing flow of compressed refrigerant out from the inner shell volume (707) of the discharge muffler (700) towards a discharge duct (20) of the encapsulated refrigerant compressor (1), wherein the discharge connector head (730) is provided on the upper shell portion (720) and the outlet section (705) is provided on the lower shell portion (710); wherein the inner shell volume (707) is divided into a second discharge muffler volume (702) and a third discharge muffler volume (703) by a dividing means (740);

wherein the first discharge muffler volume (701) and the second discharge muffler volume (702) are connected by an inlet pipe (731),

wherein the second discharge muffler volume (702) and the third discharge muffler volume (703) are connected by a tubular connecting passage (741), the tubular connecting passage (741) being formed by the partition (740),

and wherein the outlet section (705) is connected to the third discharge muffler volume (703),

it is characterized in that the preparation method is characterized in that,

the second discharge muffler volume (702) has a first set of a plurality of first chambers (708) and the third discharge muffler volume (703) has a second set of a plurality of second chambers (709).

2. The discharge muffler (700) of claim 1, wherein the upper housing portion (720) includes a plurality of chamber walls (721) extending toward the lower housing portion (710), wherein each of the first chambers (708) and each of the second chambers (709) are bounded by at least one of the chamber walls (721).

3. A discharge muffler (700) according to claim 2, wherein each of the chamber walls (721) has an end section (721a) facing the lower housing part (710), and each of the end sections (721a) has an arc-shaped opening (724).

4. The discharge muffler (700) of claim 2, wherein the upper housing part (720) comprises reinforcing ribs (722) extending transversely to the chamber wall (721).

5. The discharge muffler (700) of claim 2, wherein the first set of the plurality of first chambers includes at least two first chambers (708) and the second set of the plurality of second chambers includes at least three second chambers (709).

6. The discharge muffler (700) according to any one of claims 1 to 5, wherein the partition means (740) comprises:

-an upper partition wall (723) provided in the upper housing part (720), the upper partition wall (723) having an end section (723a) protruding into the lower housing part (710),

-a lower partition wall (711) provided in the lower housing part (710), the lower partition wall (711) having an end section (711a) protruding into the upper housing part (720),

wherein the tubular connecting passage (741) is formed between overlapping sections of the upper partition wall (723) and the lower partition wall (711).

7. The discharge muffler (700) according to claim 6, characterized in that at least a part of the lower partition wall (711) has a substantially U-shaped cross section.

8. The discharge muffler (700) according to any of the claims 1 to 5, characterized in that the discharge muffler (700) further comprises a discharge connection pipe (750) having a first end section (751) connected to the outlet section (705) and a second end section (752) for connection with the discharge duct (20) of the encapsulated refrigerant compressor (1), wherein the discharge connection pipe (750) is made of a plastic material.

9. The discharge muffler (700) according to claim 8, characterized in that the discharge connection pipe (750) is made of a polyamide based polymer material.

10. The discharge muffler (700) according to claim 8, wherein the outlet section (705) of the discharge muffler (700) comprises a tubular discharge connection extension (712) protruding from the outer surface (710b) of the lower housing part (710), wherein the first end section (751) of the discharge connection pipe (750) is inserted into the tubular discharge connection extension (712).

11. The discharge muffler (700) according to claim 8, characterized in that the second end section (752) of the discharge connection pipe (750) is inserted into a connection sleeve (760) having a groove (761) for receiving an O-ring (762).

12. The discharge muffler (700) according to any of the claims 1 to 5, characterized in that the discharge connector head (730) has a sealing surface (730a) for connection with a valve plate (530) of the encapsulated refrigerant compressor (1) having a circumferential groove (732) for receiving a first sealing element (550).

13. The discharge muffler (700) according to any of the claims 1 to 5, characterized in that the discharge connector head (730) has a protruding element (733) which serves as a stop element for a discharge valve spring (540) of the discharge valve.

14. The discharge muffler (700) according to any of the claims 1 to 5, characterized in that the discharge connector head (730) and/or the discharge muffler shell (706) are made of a polyamide based polymer material.

15. The discharge muffler (700) of claim 14, wherein the polymer material is a fiber reinforced polymer material.

16. A hermetic refrigerant compressor (1), characterized in that the hermetic refrigerant compressor (1) has:

-a compressor casing (100) having a lower casing part (110) and an upper casing part (120), wherein a discharge duct (20), a suction duct (30) and a maintenance duct (40) enter the compressor casing (100), wherein electricity is inserted into the compressor casing (100) through an element (50);

-a pump unit (10) comprising:

-a crankshaft system (200) having a crankshaft (210), a crank pin (220), a connecting rod (230) and a piston (240);

-an electric drive unit (400) having an internal wiring harness (430), a stator (420) and a rotor (410), said rotor (410) being fixed to said crankshaft (210), wherein said internal wiring harness (430) connects said electric pass-through element (50) and said stator (420);

-a crankcase (300) with a cylinder housing (310), wherein a cylinder (320) for reciprocating the piston (240) is located in the cylinder housing (310), wherein the crankshaft (210) is rotatably mounted in the crankcase (300), wherein the stator (420) is attached to the crankcase (300);

-a cylinder head assembly (500) mounted to the cylinder housing (310) of the crankcase (300), the cylinder head assembly (500) comprising a valve plate (530), a suction valve spring (520), a discharge valve spring (540) and a suction muffler (600);

-a plurality of support spring assemblies (60) for supporting the pump unit (10) in the compressor housing (100),

wherein the cylinder head assembly (500) comprises a discharge muffler (700) according to any one of claims 1 to 5, wherein the discharge muffler (700) has a discharge connection pipe (750) connected to the discharge duct (20).

Images