Compressor coupling member for connecting the drive shaft and the movable helix in a scroll compressor.

Abstract

The objective of the present invention is to design a compressor coupling member having a cost-effectively integrated counterweight. [Solution] A compressor coupling member for coupling a compressor drive shaft and a movable helix, comprising: a planar body including a front surface and a back surface facing the front surface; a cylindrical coupling neck formed integrally with the planar body, fastened to the planar body, or inserted into the planar body; and a counterweight having an arched outer shell, wherein the cylindrical axis of the cylindrical coupling neck extends perpendicularly to the plane of the planar body, and the cylindrical coupling neck protrudes axially from the planar body on the front surface of the planar body in relation to the cylindrical axis of the cylindrical coupling neck.

Description

Technical Field

[0001] The present invention relates to a compressor coupling member for coupling a drive shaft and a movable scroll in a scroll compressor, and more particularly to a compressor coupling member having a counterweight integrally formed with cost efficiency. Regarding a compressor for a gaseous fluid, such as a refrigerant, in which a drive shaft of a scroll compressor and a movably formed compressor coupling member are used to transmit drive torque.

Background Art

[0002] The present invention can be mainly used in an electric scroll refrigerant compressor for automobiles. Compression usually includes two inserts within a compressor and a compressor housing. One of the two insert helices is fixed, and the other is movable eccentrically on a circular track. Such a movable helix is also called a orbiting helix or scroll. As a result of the movement of such a helix, the volume of the compression chamber formed between the helices changes periodically, and a gaseous gas, such as a refrigerant, is sucked and compressed. The movable scroll usually moves on a circular track using an eccentric drive unit. The eccentric drive unit is composed of a drive shaft that rotates around a rotating shaft, and a compressor coupling member that is rotatably and fixedly connected to the drive shaft and rotates together with the drive shaft.

[0003] In the prior art, a rotatable compressor coupling member including an integrally formed counterweight was used to drive from the drive shaft of the compressor to the movable scroll. This means that the eccentric drive unit includes at least one drive shaft that rotates around a rotating shaft, and a compressor coupling member that rotates together with the drive shaft and includes a counterweight. Therefore, the movable scroll is eccentrically connected to the drive shaft via the compressor coupling member, and the axes of the movable scroll and the drive shaft cancel each other out.

[0004] The compressor coupling member includes a planar body as an internal component, through which the axis of rotation, which is the center of rotation of the compressor coupling member, extends perpendicularly. This planar body is also called the shaft extension of the drive shaft and can be connected to the drive shaft, for example, via a connecting neck. Furthermore, the compressor coupling member that rotates with the drive shaft includes a counterweight as an external component, which has an arc-shaped outer shape and at least partially has the form of a hollow cylindrical segment. Such a counterweight is offset rearward from the axial direction of the axis of rotation relative to the planar body, and therefore the side surface of the hollow cylindrical segment surrounds a portion of the circumference of the drive shaft within the end region of the shaft shank of the drive shaft.

[0005] For connection to the compressor coupling member, the drive shaft includes an eccentric and offset connecting neck which is integrally formed with, inserted into, or fastened to the end face of the drive shaft, and the longitudinal axis of the connecting neck is oriented to offset parallel to the longitudinal axis of the drive shaft.

[0006] Carbon steel, in particular, is used as the material for the coupling components of the compressor. This design is sufficient for the previous range of applications where it is used at a limited maximum rotational speed.

[0007] The range of use for compressor coupling members with integrally formed counterweights is limited by the load generated during operation due to the required shape. The present invention aims to enable a cost-effective manufacturing process and materials, allowing the range of use to increase speed at higher rotational speeds.

[0008] The compressor coupling member with a counterweight is a coupling member that transmits scroll compression drive from the drive shaft. The compressor coupling member is intended to partially balance the imbalance in system induction of the scroll compression unit with the coupling neck, which has a bore receptacle for the coupling neck of the drive shaft.

[0009] The load during operation generates localized stress at the connection point between the counterweight body and the sleeve, and this localized stress limits the operating range, which is dependent on the patented material properties and the geometric structure / ratios of the components. This is because the operating range of the compressor has been expanded. The maximum rotational speed must be 11,000 RPM, compared to the previous limit of approximately 9,000 RPM.

[0010] Cost is a driving force for competitiveness. For potential cost reduction, metal powder forming is chosen. However, metal powder alloys have lower mechanical load capacity due to reduced modulus and yield strength. In the form of standard coupling members in compressors, structural stresses generated during operation limit the range of motion of the components.

[0011] The load during operation generates localized stress at the connection between the counterweight body and the sleeve, and this localized stress limits the operating range, which is dependent on the material properties and the geometric structure / proportions of the parts. Due to the sintered alloy and the decrease in mechanical variables over the extended range of operating conditions, the common shapes of conventional compressor coupling members do not possess the structural robustness required for operation.

[0012] The driving parameters for component load and local stress are the compressor speed and the rotor speed, expressed in RPM. The maximum speed can be increased up to 11,000 RPM.

[0013] Under specified operating conditions, the local stress at the connection between the planar body and the counterweight body indicates that the design known in the prior art is not suitable for the use of metal sintered alloys. [Overview of the project] [Problems that the invention aims to solve]

[0014] The object of the present invention is to design a compressor coupling member having a cost-effectively integrally formed counterweight, the compressor coupling member must be suitable for operation at high rotor rotation speeds of up to 11,000 RPM. [Means for solving the problem]

[0015] The compressor coupling member includes the following: The compressor coupling member that connects the compressor's drive shaft and the movable helix is, A flat body including a front surface and a back surface facing the front surface, A cylindrical coupling neck which is formed integrally with the planar body, fastened to the planar body, or inserted into the planar body, The cylindrical axis of the cylindrical coupling neck extends perpendicularly to the plane of the planar body, and the cylindrical coupling neck protrudes axially from the planar body in relation to the cylindrical axis of the cylindrical coupling neck on the front surface of the planar body. The system includes a counterweight formed in the shape of at least partially hollow cylindrical segments and having an arched outer shell.

[0016] The counterweight is integrally formed with an outer region of the planar body that partially surrounds only the cylindrical coupling neck, and a neck peripheral region that is formed concentrically with the cylindrical axis and completely surrounds the cylindrical coupling neck, and protrudes axially from the back surface of the planar body beyond the planar body. The planar body includes opposing outer edge regions, The outer edge region begins from the arched base edge region of the planar body that partially encloses the neck peripheral region, extends to the ends of the counterweights that face each other in the arc direction of the counterweights, and extends linearly from the outer contour of the planar body in the form of increasingly spaced V-legs.

[0017] Therefore, the present invention proposes a new connection design for the main body, connecting neck, and counterweight. Compared to conventional technology, expanding the planar body into a V-shape significantly improves the rigidity and structural robustness of the compressor coupling member.

[0018] This invention enables a much more robust design with comparable footprint requirements compared to the prior art. Compressor mating members designed in this way can be manufactured, for example, by forming powder metal alloys using a powder pressing method, which saves material and cost compared to forging processes. Achievable cost reductions are estimated to be between 40% and 60%. Simultaneously, the more robust design allows for higher operating loads at higher rotor rotation speeds. As a result, compressor coupling members manufactured by metal powder forming are suitable for operation under given load conditions. This means the compressor coupling is suitable for operation at a rotor rotation speed of 11,000 RPM. This compressor coupling member can replace members designed according to the prior art with the same functionality and at a lower cost.

[0019] The connection design according to the present invention significantly reduces local maximum stress. This can be achieved by the connection design of the planar body, coupling neck, and counterweight according to the present invention.

[0020] The V-shaped extension design not only significantly improves the rigidity and structural robustness of the compressor coupling member compared to the prior art compressor coupling members, but can also be used to integrate additional support members. Thus, in order to further reinforce the compressor coupling member, a single support member or a plurality of support members can be additionally formed in the region of the planar body adjacent to the external edge region extending in the form of V legs. According to an advantageous embodiment, the support member is a reinforcing rib of a rib structure protruding axially from the planar body from the rear part of the planar body. A particularly preferred embodiment is an embodiment in which the rib structure having the reinforcing rib embodied by an additional support member extends to the counterweight. Preferably, the rib structure embodied by an additional support member includes two reinforcing ribs respectively adjacent to one of the opposing outer edge regions, and the two reinforcing ribs embodied by an additional support member each extend to one of the ends of the counterweight facing each other in the arc direction. Advantageously, the reinforcing rib embodied by an additional support member protrudes axially from the rear part of the planar body exactly to the counterweight protruding beyond the planar body from the rear part of the planar body.

[0021] For the drive connection of the compressor, the cylindrical coupling neck is provided with a receiving bore oriented eccentrically with respect to the cylindrical axis.

[0022] Thus, a further embodiment of the present invention relates to a compressor for a vapor-phase fluid in which the compressor coupling member according to the present invention is used as part of an eccentric drive unit.

[0023] The compressor includes a compressor housing and two interleaving spirals inside the compressor housing, one spiral being fixed and the other one being movable eccentrically in a circular orbit, and the compression volume formed between the spirals can be periodically changed by the movement of the spirals.

[0024] The eccentric drive unit includes a drive shaft that is rotatable, and a movable spiral that can move on a circular orbit by using the eccentric drive unit. The movable spiral is eccentrically connected to the drive shaft via the compressor coupling member in the compressor according to the present invention.

Brief Description of the Drawings

[0025] Further details, features, and advantages of the design of the present invention will become apparent from the following description of exemplary embodiments with reference to the following related drawings. [Figure 1a] It is a diagram showing a compressor coupling including a flat body, a counterweight, and a coupling neck for coupling a drive shaft and a movable spiral of a compressor according to the prior art. [Figure 1b] It is a schematic diagram of a region where the maximum local stress occurs within the compressor coupling member during operation. [Figure 2] It is a comparison diagram of a compressor coupling member formed according to the prior art and a compressor coupling member designed according to an embodiment of the present invention. [Figure 3] It is a comparison diagram comparing a compressor coupling member formed according to the prior art and a compressor coupling member designed according to an embodiment of the present invention from the perspective of the local maximum stress in the flat body region. [Figure 4] It is a diagram showing a specified width expansion of the compressor coupling member. [Figure 5a] It is a perspective view showing the coupling head of the compressor coupling member facing forward. [Figure 5b] It is a perspective view showing a housing space for accommodating the end portion of the drive shaft of the compressor coupling member facing backward. [Figure 6] It is a diagram showing a bar graph comparing the local maximum stresses by different compressor coupling members under different rotor rotation speeds.

Embodiments for Carrying Out the Invention

[0026] Figure 1a shows a conventional compressor coupling member (1*) for movable coupling with a drive shaft (not shown) of a compressor (not shown). Such a compressor coupling member (1*) includes a planar body (2*) into which a cylindrical coupling neck (3*) is integrally formed, fastened, or into which the cylindrical coupling neck (3*) is inserted, wherein the cylindrical axis (4*) of the cylindrical coupling neck (3*) extends perpendicular to the plane of the planar body (2*), and the cylindrical coupling neck (3*) protrudes axially from the planar body (2*) with respect to the longitudinal axis of the cylindrical coupling neck (3*) on the front surface (2a*) of the planar body (2*). The housing bore (5*) formed by the cylindrical coupling neck (3*) is oriented eccentrically with respect to the cylindrical axis (4*) of the cylindrical coupling neck (3*) and is designed to house a coupling neck (not shown) of a drive shaft (not shown in Figure 1a). The region that directly supports the cylindrical joint neck (3*), extends coaxially with the cylindrical axis (4*), and directly supports the cylindrical joint neck (3*), as well as the region of the planar body (2*) that completely encloses the entire circumference of the cylindrical joint neck (3*), will hereafter be referred to as the neck peripheral region (6*).

[0027] Furthermore, the counterweight (8*), which has an arc-shaped outer contour, partially encloses the neck peripheral region (6*) and is integrally formed on the outer region (7*) of the planar body (2*), which has the shape of a hollow cylindrical segment, parallel to and spaced apart from the cylindrical axis (4*) of the cylindrical joint neck (3*). Thus, the outer region (7*) connects the neck peripheral region (6*) of the planar body (2*) that supports the cylindrical joint neck (3*) to the counterweight (8*). The counterweight (8*) also protrudes axially beyond the planar body (2*), but mainly protrudes to the second back surface (2b*) of the planar body (2*) that is opposite to the front surface (2a*) containing the cylindrical joint neck (3*). Since the counterweight (8*) is at least partially hollow cylindrical segment in shape, the counterweight (8*) partially surrounds the body (2*) on one side, more precisely in the outer region (7*) of the body (2*), and thus has a receiving cavity (10*) inside the hollow cylindrical segment for partially receiving the shaft shank end region of the drive shaft (not shown in Figure 1a).

[0028] The material used for the compressor coupling member (1*) is specifically carbon steel, and the compressor coupling member (1*) is typically manufactured by forging with post-processing of the surface of at least some of the components. This method is particularly applicable to the surface areas of the planar body (2*), the cylindrical coupling neck (3*), and the housing bore (5*) from the planar body (2*) to the cylindrical coupling neck (3*). This design is sufficient for conventional use under limited maximum rotational speed conditions.

[0029] The load during operation generates localized stress at the connection between the cylindrical coupling neck (3*) and the counterweight (8*) body, limiting the operating range of the compressor coupling member (1*) depending on its material properties and geometric structure / ratio. Due to the decrease in mechanical parameters of sintered alloys and the decrease in mechanical parameters over extended operating conditions, the common shapes of conventional compressor coupling members lack the structural robustness essential for operation. The driving parameters for component load and localized stress are the compressor speed, or rotational speed, which increases up to a maximum speed of 11,000 RPM. Under given operating conditions, the localized stress at the connection between the planar body and the counterweight body indicates that known designs in the prior art are unsuitable for the use of metal sintered alloys. Figure 1b shows, with different contrasts, various regions of varying degrees of load on the compressor coupling member (1*) and the region of localized maximum stress (11*) on the compressor coupling member (1*) at the end of the outer region (7*) of the planar body (2*). As explained, the outer region (7*) is the region that supports the cylindrical coupling neck (3*) and connects the neck peripheral region (6*) of the planar body (2*) that completely encloses it to the counterweight (8*).

[0030] Figure 2 is a schematic comparison of compressor coupling members (1*, 1**) formed according to the prior art, namely, a compressor coupling member (1*) produced by a forging process, a compressor coupling member (1**) produced by a sintering process with the same design, and a compressor coupling member (1) designed according to an embodiment of the present invention. The reception of the shaft shank end region of the drive shaft (12) in the receiving space (10*) formed by the inner side of the counterweight (8*) is shown as an example of compressor coupling member (1*), and the position of the rotation axis (13) of the drive shaft (12) is also shown in perspective views of the other compressor coupling members (1**, 1), in which case each receiving space (10**, 10) partially formed inside the counterweight (8**) for the shaft shank end region of the drive shaft (12) and a receiving bore (5**, 5) in the connecting neck for accommodating a connecting neck (not shown) which is formed integrally with the surface at the beginning of the drive shaft (12) into which it can be inserted or removed are shown.

[0031] The compressor coupling member (1) of the present invention includes opposing outer edge regions (14, 15), which extend from the arched base edge region (16) of the planar body (2) that partially encloses the neck peripheral region (6) to the ends of the counterweight (8) that face each other in the arc direction of the counterweight (8), and extend linearly from the outer contour of the planar body (2) in the form of increasingly spaced V-legs. In this way, the region of the planar body 2 is expanded compared to the body (2*, 2**) of the conventional compressor coupling members (1*, 1**), and such expansion will hereafter be referred to as the V-shaped expansion of the planar body 2. As a result of the V-shaped expansion, the rigidity and robustness of the compressor coupling member (1) are significantly increased compared to the conventional compressor coupling members (1*, 1**).

[0032] Figure 3, a schematic comparison diagram, uses contrast to show the regions with different degrees of load generated by operation, and the size and location of the regions of local maximum stress (11*, 11**, 11) generated on the planar body (2*, 2**, 2). The local maximum stress on the compressor coupling member (1) according to the embodiment of the present invention is much smaller than the local maximum stress of the conventional compressor coupling member (1*, 1**).

[0033] Figure 4 is a comparative diagram combining a front view of a conventional compressor coupling member (1*) and a front view of a compressor coupling member (1) according to an embodiment of the present invention. The comparative diagram shows the front surface (2a*, 2a) of the planar body (2*, 2), the end surface of the cylindrical coupling neck (3*, 3) that protrudes from the front surface (2a*, 2a) of the planar body (2*, 2) and has a housing bore (5*, 5) that is oriented eccentrically with respect to the cylindrical axis (4), and the front end surface (17*, 17) of the cylindrical segment-shaped counterweight (8*, 8) of each compressor coupling member (1*, 1). In the combined diagram, the extended portion (18, 19) of the planar body (2) resulting from the V-shape of the outer edge region (14, 15) starting from the base edge region (16) is shown in comparison with the planar body (2*) of the conventional technology.

[0034] Figures 5a and 5b show the compressor coupling member (1) of the present invention. Figure 5a shows the front view of the cylindrical coupling neck (3), and Figure 5b shows the rear view of the compressor coupling member (1) showing a receiving space (10) partially enclosed by the inside of a counterweight (8) which is for housing the drive shaft end (not shown).

[0035] Figure 5a shows the front opening of the housing bore (5), which is positioned above the cylindrical coupling neck (3) and designed to receive the coupling neck (not shown) of the drive shaft (not shown), and the front end face of the cylindrical coupling neck (3). Figure 5b shows the rear end face of the cylindrical coupling neck (3) with the rear opening of the housing bore (5) on the opposite side. The circumference of the cylindrical coupling neck (3) is completely enclosed on the rear end face of the cylindrical coupling neck (3) by the neck peripheral region (6) of the planar body (2). In this embodiment, the cylindrical coupling neck (3) is inserted into the planar body 2.

[0036] In Figure 5a, the neck peripheral region (6) extends coaxially with the cylindrical axis 4 of the cylindrical coupling neck (3) and is shown as the region of the planar body 2 that surrounds the entire circumference of the cylindrical coupling neck (3) from its rear end.

[0037] The planar body (2) includes opposing outer edge regions (14, 15), which begin from an arched base edge region (16) of the planar body (2) that partially encloses the neck peripheral region (6), and extend from the outer contour to the counterweight (8) in the form of increasingly spaced V-legs. Compared with conventional compressor coupling members, the V-shaped extension not only significantly improves the rigidity and robustness of the compressor coupling member (1), but can also be used for extensions used to integrate additional support members (20), such as extensions (18, 19) that project axially from the front of the planar body relative to the cylindrical axis (4) of the cylindrical coupling neck (3) and support the outer edge regions (14, 15) which are arranged opposite each other in a V-shape, to the counterweight (8), or in the form of two integrated rib structures integrated into the counterweight (8). As shown in Figures 5A and 5B, the reinforcing ribs, which are additional support members 20, project axially from the back surface 2b of the planar body 2 relative to the cylindrical axis 4, and precisely project to the counterweight 8 which protrudes beyond the planar body 2 from the back surface 2b.

[0038] The bar graph in Figure 6 compares the local maximum stresses of different compressor coupling members (1*, 1**, 1) under different rotational speed conditions. The local maximum stress is [N / mm²]. 2 The values ​​are expressed in absolute units, and this graph also uses relative values ​​as a baseline, compared to the local maximum stress occurring at 8600 RPM in a forged compressor coupling member (1*) formed according to the prior art, which corresponds to 100% as shown on the right axis of the graph. As shown in the figure, the coupling design according to the present invention reduces the local maximum stress to a much lower level than 100%, and therefore can be kept below the maximum allowable operating inductive load value of the compressor coupling member (1) at all rotor rotation speeds. [Explanation of symbols]

[0039] 1, 1*, 1** Compressor coupling member 2, 2*, 2** Flat body, main body, compressor housing 2a* Front 2b* Back 2a* First front 3, 3* Cylindrical Coupling Neck 4* Cylindrical shaft 5, 5* Capacity Bore 6* Neck area 7* Outer area 8*, 8** Counterweights 10 10*, 10** Receptive space 11*, 11** Region of maximum stress 12 drive shaft 13 Rotation axis 14, 15 Outer edge region, outer edge region 16 Base edge region, arched base edge region 17, 17* Front end 18, 19 Extension part, supporting extension part 20 Support members

Claims

1. A compressor coupling member (1) that connects the drive shaft and the movable helix of the compressor, A planar body (2) including a front surface (2a) and a rear surface (2b) facing the front surface, A cylindrical coupling neck (3) is formed integrally with the planar body (2), fastened to the planar body (2), or inserted into the planar body (2), The cylindrical shaft (4) of the cylindrical coupling neck (3) extends perpendicularly to the plane of the planar body (2), and the cylindrical coupling neck (3) protrudes axially from the planar body (2) on the front surface (2a) of the planar body (2) in relation to the cylindrical shaft (4) of the cylindrical coupling neck (3). A counterweight (8) is formed in the shape of at least partially hollow cylindrical segments and has an arched outer shell, The counterweight (8) is integrally formed from an outer region (7) of the planar body (2) that partially surrounds the cylindrical coupling neck (3), and a neck peripheral region (6) that is formed concentrically with the cylindrical axis (4) and completely surrounds the cylindrical coupling neck (3), and on the back surface (2b) of the planar body (2), it protrudes axially beyond the planar body (2), The planar body (2) includes opposing outer edge regions (14, 15), The outer edge regions (14, 15) extend from the arched base edge region (16) of the planar body (2) that partially encloses the neck peripheral region (6) to the ends of the counterweight (8) that face each other in the arc direction of the counterweight (8), A compressor coupling member for connecting the compressor's drive shaft and movable helix, characterized in that it extends linearly from the outer contour of the planar body (2) in the form of V-shaped legs arranged at increasingly greater intervals.

2. The compressor coupling member according to claim 1, characterized in that, in order to reinforce the compressor coupling member (1), one or more support members (20) are further formed in the region of the planar body (2) adjacent to the outer edge region (14, 15) that extends in the shape of a V leg.

3. The compressor coupling member according to claim 2, characterized in that the plurality of support members (20) are reinforcing ribs of a rib structure that protrudes in the axial direction from the planar body (2) on the back surface (2b) of the planar body (2).

4. The compressor coupling member according to claim 3, characterized in that the rib structure having the reinforcing ribs embodied by the plurality of support members (20) extends to the counterweight (8).

5. The compressor coupling member according to claim 4, characterized in that the rib structure is embodied by a plurality of support members (20) and includes two reinforcing ribs adjacent to one of the opposing outer edge regions (14, 15).

6. The compressor coupling member according to claim 5, characterized in that the two reinforcing ribs embodied by the plurality of support members (20) each extend to one of the ends of the counterweight (8) that are opposite to each other in the arc direction.

7. The compressor coupling member according to claim 6, characterized in that the reinforcing ribs embodied by the plurality of support members (20) project precisely from the back surface (2b) of the planar body (2) to the counterweight (8) that protrudes beyond the planar body (2).

8. The compressor coupling member (1) is manufactured by a metal powder molding process, as described in claim 7.

9. The compressor coupling member (1) is manufactured by a steel powder compression method, as described in claim 8.

10. The compressor coupling member according to claim 9, characterized in that the cylindrical coupling neck (3) includes a receiving bore (5) whose orientation is set eccentrically with respect to the cylindrical shaft (4).

11. A compressor housing (2), and two interleaving spirals provided inside the compressor housing (2), One of the two interleaving helices is fixed, while the other helice is eccentrically movable on a circular orbit. The volume of the compression chamber formed between the helices can be periodically changed by the movement of the helices. The compressor coupling member (1) according to any one of claims 1 to 10 is rotatable together with the eccentric drive unit and the drive shaft (12), The other helix can move along a circular orbit using the eccentric drive unit, A compressor for a gaseous fluid, characterized in that the other helix is ​​eccentrically connected to the drive shaft (12) via the compressor coupling member (1).

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