Volumetric machine

Abstract

The invention relates to a positive displacement machine, in particular a scroll compressor, based on the spiral principle, comprising: a. A housing (10), b. An orbiting positive displacement spiral (11) and a counter-spiral (12), which engage with each other such that a variable compression chamber (13) is formed between the positive displacement spiral (11) and the counter-spiral (12), the invention relates to a positive displacement machine comprising: a. A positive displacement screw (11) for receiving and compressing a working medium flowing through a working medium circuit, c. A drive shaft (14) which is in drive connection with the positive displacement screw (11), and d. An anti-rotation mechanism (15) for guiding the positive displacement screw (11), characterized in that a bearing (16) of the drive shaft (14) is arranged in a multi-part bearing plate (17), the bearing (16) is provided with a bearing seat (19) for the bearing (16); and a second housing section (20) which is connected to the first housing section (18), the second housing section (20) protruding radially inward beyond an inner wall (22) of the first housing section (18).

Description

[0001] The present invention relates to a positive displacement machine (Verdrängermaschine) based on the spiral principle and having the features of the generic concept of claim 1. Such a positive displacement machine is known, for example, from DE 10 2016 118 525 A1.

[0002] DE 10 2016 118 525 A1 describes a positive displacement machine based on the spiral principle, which is also referred to as a scroll compressor. The positive displacement machine has a housing in which a bearing for supporting a drive shaft is arranged. The housing has a bearing seat for the bearing and a receiving space for a balancing mass for connection to the drive shaft. The drive shaft engages eccentrically into an orbiting positive displacement spiral element, which engages in a spiral manner with a counter spiral element. By the orbiting movement of the positive displacement spiral element caused by the eccentric connection to the drive shaft, a variable compression chamber is formed between the positive displacement spiral element and the counter spiral element. In operation, the compression chamber receives the working medium flowing through the working medium circuit and compresses the working medium. For this purpose, an anti-rotation mechanism is provided, which engages into an opening at the bottom of the positive displacement spiral element and prevents the positive displacement spiral element from rotating freely. In this way, the positive displacement spiral element is guided and an orbiting movement is achieved. The basic principle of such positive displacement machines is well known to the person skilled in the art.

[0003] DE 10 2016 118 525 A1 finds it advantageous if the anti-rotation mechanism is not directly connected to the housing, but to an annular sliding plate located between the housing and the positive displacement spiral element. On the one hand, the sliding plate serves to enlarge the installation space available for the bearing of the drive shaft and the balancing mass. On the other hand, a favorable material pairing between the anti-rotation mechanism and the sliding plate can be achieved. However, the known housing structure is relatively complex.

[0004] It is an object of the present invention to provide a positive displacement machine based on the spiral principle that is simple in structure and further improved in terms of installation space.

[0005] According to the invention, this object is achieved by the subject matter of claim 1.

[0006] Specifically, this object is achieved by a positive displacement machine based on the spiral principle, which has a housing, an orbiting positive displacement spiral element and a counter spiral element. The positive displacement machine is preferably a scroll compressor.

[0007] The positive displacement spiral element and the anti-spiral element are engaged with each other such that a variable compression chamber is formed between the positive displacement spiral element and the anti-spiral element to accommodate and compress the working medium flowing through the working medium circuit. The positive displacement machine has: a drive shaft which is drivingly connected to the positive displacement spiral element; and an anti-rotation mechanism which is used to guide the positive displacement spiral element. The invention is characterized in that the bearing of the drive shaft is arranged in a multi-component bearing plate, wherein the bearing plate includes a first housing section and a second housing section having a bearing seat for the bearing. The second housing section is connected to the first housing section. The second housing section projects radially inwards from the inner wall of the first housing section.

[0008] Differing from the prior art, according to the invention, the bearing is arranged in a multi-component bearing plate. This has the following advantages: Since the bearing seat is constructed in the bearing plate, the structure of the housing of the positive displacement machine is simple. Thereby, the wall thickness of the housing is reduced. In addition, since the multi-component bearing plate can be pre-assembled with the bearing, there are manufacturing technology advantages.

[0009] Another advantage of the multi-component bearing plate is the functional separation. The first housing section and the second housing section having the bearing seat can be optimized separately according to their respective functions. For example, the second housing section can be optimized and adjusted for the anti-rotation mechanism and / or sliding characteristics, but is not limited thereto. Other optimization measures are also possible.

[0010] According to the invention, the second housing section projects radially inwards from the inner wall of the first housing section. Thereby, an expansion of the installation space is achieved because the first housing section can be designed to have a correspondingly larger inner diameter while maintaining the dimensions based on the design of the positive displacement spiral element of the orbiting type. In addition, the invention simplifies the installation of the bearing and the installation of other internal components because the bearing plate can be installed separately.

[0011] In the context of the present invention, "projecting radially inwards" means that the second housing section forms a projection extending in the radial direction relative to the first housing section. For example, in an embodiment where the second housing section is configured as a ring, this means that the inner diameter of the ring is smaller than the inner diameter of the first housing section, but the invention is not limited to this embodiment.

[0012] Further embodiments of the invention are given in the dependent claims.

[0013] Therefore, the second housing section can project radially inwards from the bearing seat and / or the accommodation space for the balancing means (Ausgleichsmittel). The advantage of this is that the inner diameter of the bearing seat and / or the inner diameter of the accommodation space for the balancing means can be designed correspondingly larger. Thereby, larger drive shaft bearings and balancing means of larger mass can be used.

[0014] In a preferred embodiment, at least 20%, in particular at least 30%, of the second housing section projects freely inwards. Thereby, a correspondingly large installation space gain is achieved in the first housing section. The upper limit of the above-mentioned at least 20% or at least 30% range is determined by the contact area of the second housing section on the first housing section and the corresponding wall thickness.

[0015] Preferably, the second housing section forms a ring whose inner diameter is smaller than the inner diameter of the first housing section. Here, the inner diameter of the second housing section can be smaller than the maximum inner diameter of the first housing section. In other words, the second housing section projects completely radially inwards beyond the first housing section.

[0016] The inner diameter of the second housing section can also be locally smaller than the inner diameter of the first housing section. For example, this is the case when the first housing section has different inner diameters in the axial direction. In this case, it is sufficient as long as the inner diameter of the second housing section is smaller than at least one inner diameter section of the first housing section, preferably smaller than the inner diameter section of the first housing section adjacent to the second housing section.

[0017] In a preferred embodiment, the second housing section forms a sliding surface for the positive displacement spiral element. The advantage of this is that the oscillating movement of the positive displacement spiral element takes place with as little friction as possible.

[0018] Advantageously, the first housing section at least partially has a cylindrical inner wall. This part is, for example, provided for a bearing seat.

[0019] The first housing section can have a stepped inner wall or an inner wall with a constant inner diameter. In the case of a stepped inner wall, internal mounting parts with different outer diameters, such as bearings and balance weights, can be arranged in the first housing section. Regarding the ratio between the inner diameter of the second housing section and the maximum inner diameter of the first housing section, reference is made to the above description. The embodiment with an inner wall having a constant inner diameter has the advantage of simple manufacture. In both cases, a cylindrical geometry of the inner wall is preferred.

[0020] In another preferred embodiment, the second housing section is connected to the anti-rotation mechanism in a force-transmitting manner. For this purpose, the second housing section has a wall of appropriate strength, which is selected by a professional according to the force to be transmitted by the anti-rotation mechanism. The advantage of this embodiment is that a coordinated material pairing between the anti-rotation mechanism and the second housing section can be used. In addition, this embodiment also has the advantage of a compact structure.

[0021] Preferably, the anti-rotation mechanism is arranged in the radially inwards projecting region of the second housing section. Thereby, a space-saving arrangement of the anti-rotation mechanism is achieved.

[0022] Advantageously, the anti-rotation mechanism has pins that engage in corresponding openings in the distributor helix to guide the distributor helix, where the pins are introduced, in particular fitted, into the second housing section and are connected to the second housing section.

[0023] If at least the first housing section of the bearing plate is connected to the housing of the positive displacement machine, in particular by means of a threaded connection, a material separation from the housing of the compressor and a bearing plate that is completely located internally can be achieved.

[0024] The invention will now be described in more detail on the basis of embodiments and with reference to the attached schematic drawings. In the drawings: Figure 1 a longitudinal section of a positive displacement machine in the region of a multi-part bearing plate according to a first embodiment of the invention is shown; and Figure 2 a longitudinal section of a positive displacement machine according to a second embodiment of the invention is shown.

[0025] Figure 1 a cross-section of a positive displacement machine in the region between the low-pressure side and the high-pressure side is shown.

[0026] The drive shaft 14 is arranged in the housing 10 on the low-pressure side. For example, the drive shaft 14 is driven by an electric motor (not shown) or other drive. The electric motor can be arranged in the housing 10. Other arrangements or drive concepts are also possible.

[0027] The orbiting positive displacement helix 11 and the fixed anti-helix 12 are arranged in the housing 10 on the high-pressure side. They engage with each other in a helical manner and form a variable compression chamber 13, the volume of which changes due to the relative movement between the orbiting positive displacement helix 11 and the fixed anti-helix 12. To guide the positive displacement helix 11 on an orbiting path, an anti-rotation mechanism 15 is provided. The anti-rotation mechanism 15 engages in the positive displacement helix 11 and, in conjunction with the eccentric connection of the positive displacement helix 11 and the drive shaft 14, enables the orbiting movement of the positive displacement helix 11. During operation, the working medium flows into the variable compression chamber 13 and is compressed there. The general operating principle of such positive displacement machines is known to the person skilled in the art.

[0028] In Figure 1 it can be clearly seen that the multi-part bearing plate 17 is arranged in the housing 10. The bearing plate 17 on the one hand has the function of accommodating the internal mountings required for the movable parts and on the other hand defines the low-pressure side and the high-pressure side of the positive displacement machine.

[0029] The bearing plate 17 is arranged completely within the housing 10, i.e. internally.

[0030] Specifically, in the present embodiment, the bearing plate 17 is composed of two parts and has a first housing section 18 and a second housing section 20. The bearing plate 17 may also have other housing sections. The terms "housing sections 18, 20" mean that the bearing plate 17 forms a housing unit in the upper housing 10 of the positive displacement machine and houses internal fittings by itself.

[0031] The term "multi-part bearing plate 17" means that the bearing plate 17 is divided into multiple independent parts, namely housing sections 18, 20, at least during the assembly process. The bearing plate 17 can be referred to as an assembled bearing plate 17 composed of multiple housing sections 18, 20.

[0032] The housing sections 18, 20 are detachably connected, particularly detachably connected to the housing 10.

[0033] As Figure 1 shown, the bearing 16 of the drive shaft 14 is arranged in the bearing plate 17. For example, the bearing 16 can be a rolling bearing. Other bearing types are also possible. The bearing 16 can be referred to as the drive bearing or main bearing of the drive shaft 14.

[0034] Specifically, the bearing 16 is arranged in the first housing section 18. For this purpose, the first housing section 18 has a bearing seat 19 for the bearing 16.

[0035] The second housing section 20 is arranged on the first housing section 18 on the high-pressure side along the axial direction of the positive displacement machine and forms the high-pressure side end of the bearing plate 17. The axial direction of the positive displacement machine is defined by the longitudinal axis of the drive shaft 14.

[0036] The second housing section 20 is connected to the first housing section, particularly detachably. Different connection types can be adopted, such as Figure 1 the threaded connection shown.

[0037] The second housing section 20 has a sliding surface 21 on the high-pressure side. The positive displacement spiral 11 slides on the sliding surface 21 during operation and forms a seal with the sliding surface 21. During operation, the positive displacement spiral 11 moves relative to the sliding surface 21 or relative to the second housing section 20 on an orbiting track.

[0038] In Figure 1 it is clearly visible that the second housing section 20 projects radially inwards beyond the inner wall 22 of the first housing section 18. Due to the radial protrusion of the second housing section 20, the first housing section 18 can be enlarged. The installation space gain in the area of the first housing section 18 can be used to arrange a larger bearing 16 in the bearing plate 17 or to design other large internal fittings in the first housing section 18.

[0039] In accordance with Figure 1In the embodiment, the radial protrusion or extension is achieved in the following manner: the inner diameter of the second housing section 20 is smaller than the inner diameter of the first housing section 18.

[0040] The expression "radially inwardly protruding" does not absolutely mean that the two housing sections 18, 20 must be rotationally symmetric. Other geometries are possible, which can cause the second housing section 20 to protrude inwardly from the inner wall of the first housing section 18, thereby expanding the installation space in the area of the first housing section 18.

[0041] In accordance with Figure 1 In the embodiment, the second housing section 20 protrudes radially inwardly from the entire inner wall 22 of the first housing section 18. Specifically, the second housing section 20 protrudes radially inwardly from the bearing housing 19 and the receiving space 23 for the balancing mass 24. The receiving space 23 is also formed in the first housing section 18. Due to the eccentric mounting of the positive displacement spiral member 11, the balancing mass 24 serves as a balancing mass.

[0042] In accordance with Figure 1 In the embodiment, the bearing housing 19 and the receiving space 23 are functionally separated but not structurally separated. The inner wall of the first housing section is cylindrical. The inner diameters of the bearing housing 19 and the receiving space 23 are the same. It follows that the second housing section 20 protrudes radially inwardly from the bearing housing 19 and the receiving space 23. Other arrangements are possible.

[0043] The protruding part is at least 20%, especially at least 30% of the second housing section 20. This means that at least 20%, especially at least 30% of the area of the second housing section 20 freely protrudes inwardly from the first housing section 18. The upper limit of this area is determined by the contact surface required for the connection between the two housing sections 18, 20.

[0044] In accordance with Figure 1 In the embodiment, the second housing section 20 is configured as a ring, the inner diameter of which is smaller than the inner diameter of the first housing section 18.

[0045] The first housing section 18 is configured as cylindrical, having a bottom arranged on the low-pressure side. A through-hole for the drive shaft 18 is configured in the bottom, and this through-hole forms a seal with the drive shaft 18 through a shaft seal. The bearing 16 or the corresponding bearing housing 19 is arranged or configured at the axial end of the bottom side of the first housing section 18.

[0046] The receiving space 23 for the balancing mass 24 is configured between the bearing 16 and the freely protruding part of the second housing section 20.

[0047] The high-pressure side end of the first housing section 18 is open in the axial direction. In the assembled state, the high-pressure side end is at least partially closed by the second housing section 20.

[0048] As Figure 1 shown, the second housing section 20 is connected to the anti-rotation mechanism 15 in a force-transmitting manner. The anti-rotation mechanism 15 has a plurality of pins 25 that engage into corresponding openings 26 in the positive displacement helix 11, specifically into the bottom of the positive displacement helix 11. The pins 25 are used to guide the positive displacement helix 11 on an orbiting track. The pins 25 are fitted into the second housing section 20, specifically into the wall of the ring that forms the second housing section 20. The pins 25 project axially beyond the sliding surface 21.

[0049] The wall thickness of the second housing section 20 is dimensioned such that a force-transmitting connection with the pins 25 can be achieved. The advantage of this is that for the fixation of the pins 25 or generally for the fastening of the anti-rotation mechanism 15, no connection to the first housing section 18 or the housing 10 is required. The pins 25 and the second housing section 20 are made of the same or similar material, so the difference in the coefficient of thermal expansion of these components is small or non-existent.

[0050] The pins 25 are arranged in a radially inwardly projecting region of the second housing section 20, more precisely radially inward to such an extent that they can engage into the corresponding openings 26 in the positive displacement helix 11.

[0051] The multi-part bearing plate 17 is generally regarded as an independent unit and is connected to the housing 10, for example by a threaded connection. Other connections are also possible. The bearing plate 17 is completely accommodated in the housing 10.

[0052] The connection between the bearing plate 17 and the housing 10 can be made, for example, by arranging and fastening the bearing plate 17 between the housing 10 and the fixed anti-helix 12.

[0053] Specifically, as Figure 1 shown, the outer flange of the bearing plate 17 is clamped between the housing shoulder of the housing 10 and the fixed anti-helix 12. For this purpose, threaded connecting elements are provided that connect the housing shoulder and the anti-helix 12 and pass through the outer flange. In Figure 1 , the internal thread of the threaded connecting element is configured in the anti-helix 12. The internal thread can also be configured in the housing 10 (see Figure 2 ). This connection of the bearing plate 17 is space-saving and compact. Other connection types are also possible.

[0054] Figure 2 Another embodiment is shown, which basically corresponds to the first embodiment. For consistent features, reference is made to the description in Figure 1 .

[0055] The difference relates to the internal contour of the first housing section 18. In accordance withFigure 2 In the embodiment of Figure 2 , the bearing seat 19 and the receiving space 23 of the first housing section 18 have different inner diameters. The inner profile of the first housing section 18 is stepped.

[0056] As can be seen in Figure 2 Figure 2 , the inner diameter of the second housing section 20 is smaller than the inner diameter of the receiving space 23. Although the inner diameter of the bearing seat 18 is smaller than the inner diameter of the receiving space 23, it is still larger than the inner diameter of the second housing section 20.

[0057] Therefore, the inner diameter of the second housing section 20 is smaller than the two inner diameters of the first housing section 18. If the inner diameter of the second housing section 20 is only smaller than the inner diameter of the receiving space 23, an expansion of the partial installation space of the receiving space 23 can be achieved.

[0058] Here, the principle of the second housing section protruding radially inwards with respect to the first housing section is also given.

[0059] The multi-component bearing plate 17 enables an expansion of the installation space for receiving the bearing 16 and the balance weight 24. Therefore, these components can be designed correspondingly larger. In addition, the bearing plate 17 can be pre-assembled with the bearing 16, the drive shaft 14, and the balance weight 24, thereby simplifying the manufacturing process.

[0060] List of reference signs

Claims

1. A positive displacement machine based on the spiral principle, in particular a scroll compressor, said positive displacement machine comprising: a. A housing (10), b. A orbiting positive displacement spiral member (11) and a counter spiral member (12), said positive displacement spiral member (11) and said counter spiral member (12) being engaged with each other such that a variable compression chamber (13) is formed between said positive displacement spiral member (11) and said counter spiral member (12) to accommodate and compress the working medium flowing through the working medium circuit, c. A drive shaft (14) which is drivingly connected to said positive displacement spiral member (11), and d. An anti-rotation mechanism (15) for guiding said positive displacement spiral member (11), characterized in that the bearing (16) of said drive shaft (14) is arranged in a multi-component bearing plate (17), wherein said bearing plate (17) comprises: a first housing section (18) having a bearing seat (19) for said bearing (16); and a second housing section (20) connected to said first housing section (18), wherein said second housing section (20) projects radially inwards beyond the inner wall (22) of said first housing section (18).

2. The positive displacement machine according to claim 1, characterized in that said second housing section (20) projects radially inwards beyond said bearing seat (19) and / or the accommodation space (23) for the balance weight (24).

3. The positive displacement machine according to any one of the preceding claims, characterized in that said second housing section (20) forms a ring, the inner diameter of which is smaller than the inner diameter of said first housing section (18).

4. The positive displacement machine according to any one of the preceding claims, characterized in that said second housing section (20) forms a sliding surface (21) for said positive displacement spiral member (11).

5. The positive displacement machine according to any one of the preceding claims, characterized in that said first housing section (18) at least partially has a cylindrical inner wall (22).

6. The positive displacement machine according to any one of the preceding claims, characterized in that said first housing section (18) has a stepped inner wall (22) or an inner wall (22) with a constant inner diameter.

7. The positive displacement machine according to any one of the preceding claims, characterized in that said second housing section (20) is connected to said anti-rotation mechanism (15) in a force-transmitting manner.

8. The positive displacement machine according to any one of the preceding claims, characterized in that said anti-rotation mechanism is arranged in the radially inwards projecting region of said second housing section.

9. The positive displacement machine according to any one of the preceding claims, characterized in that said anti-rotation mechanism (15) has a pin (25) which engages into an opening (26) in said positive displacement spiral member (11) to guide said positive displacement spiral member (11), wherein said pin (25) is introduced into said second housing section (20) and connected to said second housing section (20).

10. The positive displacement machine according to any one of the preceding claims, characterized in that At least the first housing section (18) of the bearing plate (17) is connected to the housing (10), in particular by screwing.

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