Rotary machine

Abstract

A rotary machine, comprising: a housing, which has a first housing portion and a second housing portion that are arranged adjacently in the axial direction of the machine, the second housing portion being provided with a recessed part on the side of the second housing portion facing the first housing portion; a rotor, which comprises a rotor impeller rotating about a rotor axis, wherein the rotor impeller comprises a plurality of rotor blades and is configured to exchange the pressure of an airflow of the rotor blades and the rotational kinetic energy of the rotor, the airflow being able to flow through an airflow channel; and a back disk, which is axially arranged opposite the back surfaces of the plurality of rotor blades and is accommodated in the recessed part, the recessed part and the back disk defining a back disk cavity, wherein a gas guide part is provided at the recessed part, such that the airflow channel and the back disk cavity can be in communication with each other by means of the gas guide part, and the gas guide part is configured to enable gas to perform a swirling motion in the gas guide part. By means of the swirling motion in the gas guide part, the speed of the airflow entering and exiting the back disk cavity can be reduced, thereby delaying changes in the back pressure in a transient state.

Description

Rotating Machine Technical Field

[0001] This invention generally relates to rotating machines, and more particularly to compressors, turbines, and turbocompressors. More specifically, this invention relates to rotating machines in which a rotor and a back disk facing the back of the rotor blades are disposed. Background Technology

[0002] Common rotating machines in the mechanical field include a rotor housed in a casing and provided with fluid passages for fluid to flow through, such as compressors or turbines. In such rotating machines, the rotor is rotatably mounted on a shaft and has a rotor impeller. The rotor impeller is used to exchange the pressure of the fluid, such as an airflow, with the rotor's kinetic energy through its pairs of blades, for example, to pressurize the gas. Within the casing of the rotating machine, plates or discs may also be arranged axially opposite to the blades of the rotor impeller for, for example, diffusion.

[0003] The casing of a rotating machine may have a chamber in its wall to house the plate or disc. This chamber is in fluid communication with the fluid passage within the casing through which the fluid flows through the rotating machine. This allows a portion of the fluid flowing within the rotating machine to flow into and out of the space between the chamber wall and the plate or disc, i.e., the back plate cavity, during operation, where it accumulates and generates pressure. The back pressure in the back plate cavity, combined with the pressure generated by the fluid flowing over the impeller blades, acts on the impeller blades of the rotor. This produces a resultant force acting on the rotor of the rotating machine, which can be called the "rotor axial force".

[0004] Figure 1 shows a longitudinal cross-sectional view of a conventional turbo compressor 1000x for a vehicle, obtained by cutting along the longitudinal mid-plane of the turbo compressor 1000x. Figure 2 shows an enlarged view of detail DA from Figure 1. On the left side of Figure 1 is the compressor of the turbo compressor 1000x. The compressor includes a rotor CRx. Gas flowing in from the compressor inlet acts on the rotor CRx in the axial direction A, generating a blade-side gas pressure P1x. Meanwhile, in the back disk cavity BDCx (see Figure 2), gas acting on the compressor's back disk BDx in the axial direction A generates a wheel-back gas pressure P2x. The resultant force of the gas pressures P1x and P2x acting on the compressor rotor CRx in opposite directions is the "rotor axial force" mentioned above.

[0005] Currently, in this field, bearings are provided at the main shaft of a rotating machine, such as the axle of a turbo compressor, to counteract the axial force on the rotor. In other words, the rotor of the rotating machine is held axially by means of these bearings.

[0006] However, it has also been found in the art that when the operating conditions of a rotating machine change, such as during the sudden acceleration or deceleration of a vehicle including the aforementioned turbo compressor 1000x, the axial force of the rotor changes, resulting in transient peaks. If these transient changes are drastic, they are detrimental to the operation of the rotating machine. Furthermore, such transient changes can also cause vibrations at the axles and generate noise. In addition, excessively large transient peaks in the axial rotor force can shorten the service life of the aforementioned bearings, thereby affecting the service life and operating costs of the rotating machine.

[0007] Therefore, in this field, it is desirable to balance the loads of these two pressures on the rotor in the axial direction, so as to minimize the rotor axial force, smooth out the changes in the rotor axial force, and reduce the peak value if possible, thereby improving the service life of the bearing and improving vibration and noise at the rotor shaft.

[0008] Those skilled in the art have proposed several solutions to address this problem. For example, it has been envisioned to add a fluid seal made of a sufficiently flexible material to the blades of the rotor impeller in such a rotating machine to seal the back disk cavity relative to the gas flowing within the rotating machine. However, even though the fluid seal is made of a sufficiently flexible material, it still has to continuously contact and rub against the rotor blades as the rotor impeller rotates, which may still affect the rotor blades, and the seal itself also needs to be replaced due to wear.

[0009] Furthermore, in order to accommodate the fluid seal and ensure a sealing effect, the gap between the rotor's back plate and the housing wall of the chamber containing the back plate needs to be reduced in this design, which would adversely affect the flow field within the rotating machine.

[0010] Therefore, it is still desirable in this field to propose other solutions to balance the axial pressure load at the axle of rotating machines, reduce the axial force of the rotor, and thereby improve the vibration and noise generated at the axle of rotating machines. Summary of the Invention

[0011] The present invention was made in view of the above-mentioned technical problems, and its object is to provide a rotating machine in which the rotor axial force in the axial direction is improved, and the change of the rotor axial force can be mitigated when the rotating machine switches between different operating conditions.

[0012] To solve the above-mentioned technical problems, the present invention proposes a rotating machine, comprising:

[0013] The housing includes a first housing portion and a second housing portion, which are arranged adjacent to each other along the axial direction of the rotating machine and an airflow passage is formed between the first housing portion and the second housing portion for fluid, such as gas, in the rotating machine to flow through. The second housing portion has a recess on its side facing the first housing portion.

[0014] The rotor is housed in the casing of a rotating machine and includes a rotor impeller that rotates about a rotor axis. The rotor impeller includes multiple rotor blades and is configured to exchange the pressure of the airflow passing through the rotor blades with the rotational kinetic energy of the rotor. The airflow can flow through the aforementioned airflow passage.

[0015] The back disk is disposed on the ground facing the back surfaces of the plurality of rotor blades along the axial direction and is housed in the aforementioned recess of the second housing portion, which together with the back disk defines a back disk cavity.

[0016] The recessed portion is provided with a gas guide portion, which allows the airflow channel and the back plate cavity to be fluidly connected through the gas guide portion. The gas guide portion is configured to allow the gas to move in a vortex within the gas guide portion.

[0017] Thus, in the rotating machine according to the invention, a gas circuit is formed between the airflow channel, the gas guide, and the back plate cavity. In this gas circuit, gas can undergo vortex motion in the gas guide before flowing into or out of the back plate cavity. It has been demonstrated that vortex motion can slow the rate at which gas flows into or out of the back plate cavity, thereby delaying the transient surge in back pressure in the back plate cavity when the rotating machine switches between different operating conditions, and thus delaying the occurrence of the transient peak of the rotor axial force acting on the rotor. Furthermore, vortex motion also helps to maintain the balance of axial loads in the rotating machine and reduces vibrations and resulting noise during operating condition switching. In addition, by improving the balance of axial loads in the rotating machine, the thrust load acting on the bearings located at the axles in the rotating machine is reduced, which can extend the bearing service life and thus extend the service life of the rotating machine, reducing maintenance costs.

[0018] Within the scope of this invention, unless otherwise stated, "vortex motion" refers to the rotational motion of a fluid around an axis. Here, vortex motion of gas in a gas guide refers to the rotational motion of gas around an axis, such as an axis orthogonal to the longitudinal section of a rotating machine, within the gas guide. In this context, the axis may also have a certain radius, meaning the trajectory of the gas's rotation around the axis will not be within that radius.

[0019] Here, the aforementioned side of the second housing portion facing the first housing portion and having a recess thereon refers to the side of the second housing portion that is axially opposite to the end portion of the first housing portion of the rotating machine. The end portion of the first housing portion of the rotating machine typically does not have the side portion that leads to the inlet and outlet of the rotating machine; this side portion is spaced apart from the side portion with the recess, and this distance is sufficient to form an airflow passage connecting the inlet and outlet of the rotating machine.

[0020] The recess is provided on the aforementioned side portion of the second housing portion and extends further outward in the axial direction starting from the axial end face of the side portion.

[0021] Here, the wall of the recessed portion accommodating the back plate, the bottom of the recessed portion, and the back side of the back plate, that is, the side of the back plate facing away from the rotor blades, together define the back plate cavity. The back plate cavity is bounded by the wall and bottom of the recessed portion and the back side of the back plate. Gas in the gas flow path of the rotating machine may flow into the back plate cavity, specifically into the part of the space not occupied by the back plate, and can accumulate therein, generating pressure.

[0022] In a non-limiting embodiment of the present invention, the gas guide may be disposed in the second housing portion of the housing, directly connecting the airflow channel and the back plate cavity, so that gas flowing into the back plate cavity from the airflow channel or flowing out of the back plate cavity into the airflow channel can only flow through the gas guide.

[0023] In another non-limiting embodiment of the present invention, in addition to the airflow circuit described above—airflow channel-gas guide-back disk cavity—another circuit may also exist: airflow channel-back disk cavity. In the latter circuit, the gas in the airflow channel can flow directly into or out of the back disk cavity without entering the gas guide and undergoing vortex motion therein.

[0024] Ideally, in the rotating machine according to the invention, the gas guide is configured to include at least one groove. This at least one groove is configured to extend axially away from the bottom of the recess, also referred to below as extending axially outward. The at least one groove is formed on the end face of the aforementioned side portion of the second housing portion, extending at an angle in the circumferential direction about the rotor axis. Further, the at least one groove includes a first groove that extends at a first angle in the circumferential direction about the rotor axis, and the first groove has a first depth.

[0025] Here, at least one groove in the gas guide extends outward in the axial direction from the bottom of the recess. Therefore, when viewed in the axial direction of the rotating machine, the groove is located behind the back plate of the rotor of the rotating machine, and in the radial direction, the groove is located no further than the outermost radial edge of the recess, and thus the groove is located no further than the diameter of the back plate.

[0026] The above arrangement allows the at least one groove in the gas guide to be obtained by further machining the existing recess in the second housing portion. Therefore, the machining process of the groove is simple and the production cost is low.

[0027] In a non-limiting preferred embodiment of the invention, the gas guide includes a plurality of independent first grooves as described above. The sum of the first angles of each of the plurality of first grooves is less than 360°.

[0028] On the side portion of the second housing section of the rotating machine, the plurality of first grooves are arranged at the same radial position relative to the axis of rotation of the rotating machine. Each of the plurality of first grooves extends only an arc segment, rather than extending the entire circumference, and the individual first grooves do not overlap or communicate with each other. The arrangement of the plurality of first grooves provides multiple communication paths between the airflow channel and the back plate cavity.

[0029] More preferably, in the rotating machine according to the invention, the first angles of each of the plurality of first grooves are equal to each other. The first angles of the plurality of first grooves are, for example, 60° or 90°, and the plurality of first grooves are evenly spaced in the circumferential direction.

[0030] This results in the uniform distribution of multiple first grooves on the side of the second housing portion of the rotating machine. This facilitates a uniform flow field distribution on the back of the rotor impeller.

[0031] In another non-limiting preferred embodiment of the invention, the gas guide includes a first groove with a first angle of 360°. Here, the gas guide includes an annular first groove. This first groove enables fluid communication between the airflow channel and the backplate cavity throughout the entire circumferential direction. This contributes to a uniform flow field distribution and simplifies manufacturing.

[0032] Furthermore, in a preferred embodiment of the present invention, the gas guide portion disposed at the second housing portion further includes at least one second groove. The second groove is also formed on the end face of the aforementioned side portion of the second housing portion, and is radially spaced from the first groove described above and disposed radially inside the first groove. The second groove has a second depth, and is configured such that gas entering the gas guide portion must pass through both the first groove and the second groove successively.

[0033] Specifically, when the gas enters the back disk cavity from the airflow channel, the gas first passes through the first groove and can undergo vortex motion in it, then enters the second groove and can undergo vortex motion or near-vortex motion again in the second groove, and finally flows into the back disk cavity.

[0034] It has been demonstrated that, in the aforementioned flow path, the gas may approximately stagnate in the second groove, or it may undergo vortex motion in the first groove before flowing out of the first groove, without re-entering the back plate cavity. This will be further explained below.

[0035] Conversely, when the gas leaves the back plate cavity, it first flows into the second groove, where it undergoes vortex motion. Then, the gas enters the first groove and can undergo vortex motion or near-vortex motion again in the first groove before finally flowing into the airflow channel.

[0036] It has also been demonstrated that, in the aforementioned flow path, the gas may approximately stagnate in the first groove, or undergo vortex motion in the second groove before flowing out of the second groove and back into the back plate cavity, without ultimately flowing into the airflow channel. This will be further explained below.

[0037] The reduction in the amount of fluid flowing into the back plate cavity or into the airflow channel can further reduce the pressure in the back plate cavity, thereby reducing the back pressure of the rotor, and also helps to reduce the rotor axial force acting on the rotor.

[0038] Here, the second groove is arranged radially spaced from the first groove. Similar to the first groove, the second groove can also be an annular groove, extending 360° circumferentially around the rotor axis, or it can be an arc extending only around the rotor axis. In the latter case, one or more extended arc segments of the second groove can be provided.

[0039] In a preferred, non-limiting embodiment, the gas guide includes a plurality of second grooves extending only in the form of arcs. They extend around the rotor axis in the circumferential direction through the same angle, i.e., a second angle, and are evenly spaced apart from each other in the circumferential direction.

[0040] In another, less preferred, limiting embodiment, the second groove included in the gas guide is arranged in the form of an annulus, i.e., the second angle is 360°.

[0041] By setting two grooves in the gas guide section, the gas can be forced to undergo at least one vortex motion in the gas guide section, and can also undergo a rotational motion similar to vortex motion, so that less gas will flow directly from the airflow channel into the back plate cavity or flow directly from the back plate cavity into the airflow channel.

[0042] The rotational motion of the gas, especially vortex motion, and particularly preferably continuous vortex motion, can slow down the flow velocity of the gas flowing into or out of the back disk cavity through the gas guide, and can reduce the amount of gas flowing into or out of the back disk cavity. This reduces the axial load on the rotor of the rotating machine in steady state, thereby further reducing the pressure on the back of the rotor blades.

[0043] Furthermore, in a non-limiting preferred embodiment of the invention, the second depth of the second groove included in the gas guide is equal to or less than the first depth of the first groove. In other words, the first groove located radially outward has a greater depth and can therefore accommodate a relatively larger amount of gas within it to undergo vortex or rotational motion.

[0044] Preferably, the first depth of at least one first groove is 2 mm.

[0045] Preferably, the first depth of the first trench and the second depth of the second trench are the same.

[0046] More preferably, the first depth of the first trench and the second depth of the second trench are both 2 mm.

[0047] In a non-limiting preferred embodiment of the invention, the first groove in the gas guide is located at the outermost radial edge of the recess. If the opening position of the first groove is further outward in the radial direction relative to this position, it will exceed the maximum diameter of the rotor's back plate. In this case, the amount of gas flowing directly into the back plate cavity from the airflow channel without passing through the gas guide and flowing directly out of the back plate cavity into the airflow channel will increase. This gas will not undergo vortex motion and therefore will not slow down its flow velocity.

[0048] Furthermore, in the gas guide of the rotating machine according to the invention, at least one groove has a groove width. That is, at least one groove has at least a majority of a cross-section with a constant shape in the longitudinal section of the rotating machine, and the groove width is the distance between the radially inner edge and the radially outer edge of the groove.

[0049] Ideally, the width of the trench should be between 1.5 and 2.5 mm.

[0050] In a non-limiting preferred embodiment, the groove has a generally rectangular cross-sectional shape when viewed in a longitudinal section of the rotating machine. Preferably, the bottom of the rectangle has a chamfer. More preferably, the radius of the chamfer at the bottom of the rectangle ranges from 0.5 to 1.0 mm.

[0051] In another non-limiting preferred embodiment, when viewed in a longitudinal section of the rotating machine, the groove has a cross-sectional shape comprising a rectangle and an arcuate section axially outside the rectangle, wherein the arcuate section is further away from the rotor's back plate in the axial direction than the rectangle.

[0052] Preferably, in the cross-section of the groove, the arc-shaped segment connects with the rectangular shape, and the chord length of the arc-shaped segment is equal to the length of the base of the rectangular shape.

[0053] More preferably, the arc-shaped segment is constructed as a semi-circle, having a diameter equal to the length of the base side of the rectangular shape.

[0054] In a non-limiting embodiment of the invention, the rotating machine is configured such that gas entering the rotating machine passes through rotor blades and flows into an airflow passage. In this case, the rotating machine is configured as a compressor, such as an air compressor. Gas flows in from the compressor inlet, passes through the rotor, exchanges its pressure and kinetic energy with the rotor, and then flows into the airflow passage. During the flow into the airflow passage, a portion of the gas may flow into a gas guide and undergo vortex motion therein, before flowing into the back plate cavity. Subsequently, fluid accumulated in the back plate cavity may also flow out from the back plate cavity, undergo vortex motion in the gas guide, and then flow out into the airflow passage, ultimately flowing to the compressor outlet.

[0055] In another non-limiting embodiment of the invention, the rotating machine is configured such that gas entering the rotating machine flows through an airflow channel and toward the rotor blades. Here, the rotating machine is configured, for example, a turbine, where gas flows into the airflow channel from the turbine inlet and out of the airflow channel before flowing toward the rotor blades to drive the rotor to rotate. In this case, some of the gas flowing through the airflow channel may flow into a gas guide and swirl therein, before flowing into the back disk cavity, where it accumulates and increases the back pressure of the turbine rotor. Subsequently, the fluid accumulated in the back disk cavity may also flow out of the back disk cavity, swirl in the gas guide, flow back into the airflow channel, and finally flow toward the turbine outlet.

[0056] The rotating machine according to the present invention, in cases of limited axial space, does not require additional seals and can be obtained by further processing the second housing portion of the existing rotating machine housing. Its manufacturing process is simple, and it does not require additional seals as in the prior art mentioned at the beginning of this document, nor does it require reducing or adjusting the axial clearance between the shrinking back plate and the second housing portion.

[0057] The present invention also proposes a turbo compressor, particularly a turbo compressor for vehicles, comprising: a compressor having a housing, an intermediate body, a turbine having a housing, and a wheel axle.

[0058] The compressor impeller of the compressor and the turbine impeller of the turbine are respectively located at two ends of the shaft.

[0059] The intermediate body is positioned around the axle between the compressor and the turbine, and engages with both the compressor housing and the turbine housing.

[0060] The compressor or turbine is a rotating machine constructed as described in any of the foregoing embodiments, wherein the housing of the compressor (or "volute") or the housing of the turbine constitutes the first housing part of the rotating machine, and the intermediate body constitutes the second housing part of the rotating machine.

[0061] In the turbo compressor according to the present invention, the balance of axial load on the turbine shaft is improved. Specifically, the balance of gas pressure on the compressor impeller blade side, gas pressure on the compressor impeller back, gas pressure on the turbine impeller back, and gas pressure on the turbine impeller blade side is improved, thereby reducing the axial tension on the turbo compressor shaft, which in turn reduces the axial load on the bearings provided in the intermediate body of the turbo compressor to hold the shaft, extends the service life of the bearings, and further extends the service life of the turbo compressor, thereby reducing the maintenance cost of the turbo compressor.

[0062] Additional features and advantages described herein will be set forth in the detailed description below, and will be recognized by those skilled in the art as will be apparent from the following description or from practice of the embodiments described herein, including the detailed description below, the claims, and the accompanying drawings. Attached Figure Description

[0063] With reference to the above objectives, the technical features of the present invention are clearly described in the following claims, and its advantages become apparent from the following detailed description with reference to the drawings, which are intended to be non-limiting, in which:

[0064] Figure 1 shows a longitudinal cross-sectional view of a turbo compressor in the prior art;

[0065] Figure 2 is a detailed view of detail DA in Figure 1;

[0066] Figure 3 shows a longitudinal cross-sectional view of a turbine compressor according to a first embodiment of the present invention;

[0067] Figure 4 is a detailed view of the DB in Figure 3;

[0068] Figure 5 shows a simulation cloud map comparison between the turbo compressor according to the prior art and the turbo compressor shown in Figure 3;

[0069] Figure 6 shows a perspective view of an intermediate body of a turbo compressor according to a second embodiment of the present invention;

[0070] Figure 7 shows a longitudinal cross-sectional view of a turbine compressor according to a third embodiment of the present invention;

[0071] Figure 8 is a detailed view of the DC detail in Figure 3;

[0072] Figure 9 shows a perspective view of the intermediate body of the turbo compressor shown in Figure 7;

[0073] Figure 10 shows a simulation cloud map comparison between a turbo compressor according to the prior art and the turbo compressor shown in Figure 7;

[0074] Figure 11 shows a simulation cloud diagram comparison between a turbo compressor according to the prior art and a turbo compressor according to the fourth embodiment of the present invention;

[0075] Figure 12 shows a simulation cloud diagram comparison between a turbo compressor according to the prior art and a turbo compressor according to the fifth embodiment of the present invention;

[0076] Figure 13 shows a simulation cloud diagram comparison between a turbo compressor according to the prior art and a turbo compressor according to the sixth embodiment of the present invention; and

[0077] Figure 14 shows a simulation cloud diagram comparison between a turbo compressor according to the prior art and a turbo compressor according to the seventh embodiment of the present invention. Detailed Implementation

[0078] Reference will now be made in detail to various embodiments of the invention, which are illustrated in the accompanying drawings and described below. Although the invention will be described in conjunction with exemplary embodiments, it should be understood that this specification is not intended to limit the invention to those exemplary embodiments. Rather, the invention is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of the invention as defined by the appended claims.

[0079] For ease of interpretation and precise definition in the appended claims, the terms “upper,” “lower,” “inner,” and “outer” are used to describe features with reference to their positions in the exemplary embodiments shown in the figures.

[0080] In the following text, for clarity, the same components in different embodiments will be given the same reference numerals, and variations of the same components between different embodiments will be given the same main reference numerals and distinguished thereafter by an additional ''.

[0081] The turbo compressor, referred to as 1000 and 1000', is described below in conjunction with Figures 3 to 14.

[0082] [Example 1]

[0083] Figure 3 shows a longitudinal cross-sectional view of the turbo compressor 1000 according to Embodiment 1, with the mid-plane along the longitudinal direction.

[0084] The turbo compressor 1000 includes a compressor CM located on the left side of Figure 3, a turbine TM located on the right side of Figure 3, and an intermediate body CH located between the compressor CM and the turbine TM. The intermediate body CH is joined to the turbine housing TMH of the turbine TM and the compressor housing CMH of the compressor CM on both sides.

[0085] The rotor CR of the compressor CM and the rotor TR of the turbine TM are rotatably mounted on both ends of the axle AX of the turbine compressor 1000 about their respective axes of rotation. The axle of the turbine compressor 1000 passes through the intermediate body CH. A bearing (not shown in detail in the figure) for holding the axle AX in the axial direction A can be installed in the intermediate body CH, and a cooling structure for cooling the turbine compressor 1000 can also be provided therein.

[0086] A recess R extending outward along the axial direction A is provided on the side S1 of the intermediate body CH facing the compressor housing CMH, for accommodating the back plate BD of the compressor CM. The back plate BD is opposite to the rotor blades of the rotor CR of the compressor CM along the axial direction A.

[0087] In the illustrated embodiment, the recess R is constructed in a two-stage stepped shape and is formed by a recess wall RW and a recess bottom RB. The recess R accommodates the back plate BD in the first and second stages. In the second stage, a sealing plate assembly SPA is also fitted onto the axle AX on the axially outer side of the back plate BD. A sealing ring SR is provided between the sealing plate assembly SPA and the recess wall RW for fluid sealing.

[0088] The back plate cavity BDC is defined by the recess wall RW of the recess R, the bottom of the recess RB, and the back side BDS of the back plate BD of the compressor CM.

[0089] An airflow passage FP is formed between the compressor housing CMH and the intermediate body CH on opposite sides S1 and S2 along the axial direction of the compressor CM. Gas flowing in from the inlet IL of the compressor CM increases in pressure after passing through the rotating rotor CR and flows into the airflow passage FP, from where it can flow to the outlet of the compressor CM.

[0090] However, after the gas flows through the rotor CR and before it flows along the airflow passage FP to the outlet of the compressor CM, it may enter the back plate cavity BDC via inlet I1, which is formed by the gap between the outermost radial edge RE of the recess R and the outermost radial edge of the back plate BD of the compressor CM.

[0091] The gas flowing into the back disk cavity (BDC) accumulates and builds pressure within it, which then acts on the back side of the rotor blades (CR) of the compressor (CM). As the compressor (CM) rotates, this gas may later flow out of the back disk cavity (BDC), back into the airflow passage (FP), and eventually flow to the outlet of the compressor (CM).

[0092] On the side S1 of the intermediate body CH facing the compressor housing CMH, a gas guide is provided at the end face where the recessed portion R is located. As can be seen in FIG4, at the outermost radial edge RE of the recessed portion R, that is, at the first step of the recessed portion R in this embodiment, a first groove G1 is provided extending outward from the bottom RB of the recessed portion in the axial direction.

[0093] In the illustrated embodiment, the first groove G1 is constructed with a rectangular cross-section and has a first groove depth G1D and a first groove width G1W. In the illustrated embodiment, the first groove depth G1D is 2.5 mm and the first groove width G1W is 2 mm.

[0094] In this embodiment, the first groove G1 is constructed to extend 360° around the wheel axle AX in a ring shape at the outermost radial edge RE of the recess R.

[0095] Figure 5 shows a simulation comparison of the existing design turbo compressor and the turbo compressor of this embodiment under the same inflow gas conditions. Figures (a) and (b) show a comparison of gas flow velocity cloud maps near the inlet I1; Figures (c) and (d) show a comparison of gas pressure distribution cloud maps at the blades of the rotor CR of the compressor CM, the airflow passage FP, and a portion of the back disk cavity BDC; Figures (e) and (f) show a comparison of gas pressure distribution cloud maps near the inlet I1 where the airflow passage FP enters the first groove G1; Figures (g) and (h) show a comparison of pressure distribution cloud maps on the back side of the same blade of the rotor CR of the compressor CM.

[0096] Comparing Figures (a) and (b) in Figure 5, it can be seen that after the gas flows from the gas flow channel FP through the inlet I1 into the first groove G1, the gas undergoes rotational motion around an axis perpendicular to the plane of the paper within the first groove G1. Compared to the simulation results of existing designs, the velocity lines flowing from the first groove back into the back disk cavity BDC are sparser and relatively lighter in color.

[0097] It has been demonstrated that the setting of the first groove G1 helps to delay the occurrence of transient peak values ​​of axial thrust load in the turbo compressor 1000 when switching operating conditions.

[0098] [Example 2]

[0099] Figure 6 shows the intermediate body CH of the turbo compressor according to Embodiment 2. The difference between Embodiment 2 and Embodiment 1 described above is that the first groove G1 located at the outermost radial edge RE of the recess R is not constructed as a single ring, but is constructed as six first grooves G1' extending in an arc around the axis of the wheel axle AX in the circumferential direction.

[0100] In the illustrated embodiment, the six first grooves G1' are spaced apart by equal distances, do not overlap, and extend in the circumferential direction through the same first angle around the axis of the wheel axle AX.

[0101] The uniform arrangement of such multiple first grooves G1' on the side S1 of the intermediate body CH has proven to be beneficial to the flow field.

[0102] [Example 3]

[0103] Figure 7 shows a longitudinal cross-sectional view of the turbo compressor 1000' according to Embodiment 3, with the mid-plane along the longitudinal direction.

[0104] The difference between the turbo compressor 1000' and the turbo compressor 1000 according to Embodiment 1 described above is that a first groove G1” is provided at the outermost radial edge RE of the recess R provided on the side S1 of the intermediate body CH, and a second groove G2 is also provided radially inward from the first groove G1” and spaced apart from the first groove G1” in the radial direction.

[0105] In this embodiment, the first groove G1” is constructed to extend 360° around the axis of the wheel axle AX at the outermost radial edge RE of the recess R. The second groove G2 is also constructed to extend 360° around the axis of the wheel axle AX at the radially inward position of the first groove G1”.

[0106] The second groove G2 is designed not to directly connect with the inlet I1 of the airflow channel FP into the first groove G1”, ensuring that the gas flowing from the airflow channel FP into the back disk cavity BDC must first flow into the first groove G1”, then into the second groove G2, and finally into the back disk cavity BDC. Conversely, the gas flowing out of the back disk cavity BDC must pass through the first groove G1” after entering the second groove G2 before flowing back into the airflow channel FP, and then further out of the compressor CM from the airflow channel FP.

[0107] Figure 8 shows a magnified view of the DC details in Figure 7.

[0108] As shown in Figure 8, in Embodiment 3, the first groove G1” has a first depth G1”D of 2 mm. The second groove G2 has a second depth G2D that is less than the first depth G1”D. The first groove G1” and the second groove G2 have the same first width G1”W and second width G2W. In the illustrated embodiment, both the first width G1”W and the second width G2W are 2 mm. Both the first groove G1” and the second groove G2 are constructed to have a rectangular cross-section in this embodiment.

[0109] In the illustrated embodiment, the first groove G1” and the second groove G2 have a chamfer with a radius of 0.5 mm at the bottom of the rectangular cross-section.

[0110] Figure 9 shows a perspective view of the intermediate body CH according to Embodiment 3, viewed at an angle toward its side S1. As can be seen in Figure 9, a second groove G2 is provided around the opening in the middle of the intermediate body CH for accommodating the wheel axle AX, and a first groove G1 is provided radially outside the second groove G2.

[0111] Figure 10 shows a simulation comparison of the existing design turbo compressor and the turbo compressor of Example 3 under the same inflow gas conditions. Figures (a) and (b) show a comparison of gas flow velocity cloud maps near inlet I1; Figures (c) and (d) show a comparison of gas pressure distribution cloud maps at the blades of the rotor CR of the compressor CM, at the airflow passage FP, and at a portion of the back disk cavity BDC; Figures (e) and (f) show a comparison of gas pressure distribution cloud maps near inlet I1 where the airflow passage FP enters the first groove G1”, at the first groove G1”, and at the second groove G2; Figures (g) and (h) show a comparison of pressure distribution cloud maps on the back side of the same blade of the rotor CR of the compressor CM.

[0112] Comparing Figures (a) and (b) in Figure 10, it can be seen that after the gas flows from the gas flow channel FP into the first groove G1” through the inlet I1, the gas can rotate around an axis perpendicular to the plane of the paper at the position indicated by N2 in the first groove G1”, and then perform an approximately rotating motion at the position indicated by N3 in the second groove G2.

[0113] In other words, a portion of the gas is approximately stagnant in the second trench G2.

[0114] Comparing Figures (c) and (e) with Figures (d) and (f) in Figure 10, it can be seen that the gas pressure in the back disk cavity BDC is significantly lower than the pressure in the back disk cavity in the existing design, and the gas pressure in the back disk cavity BDC is also lower than that in Figures (d) and (f) in Figure 5.

[0115] Comparing Figure (g) and Figure (h) in Figure 10, it can be seen that the pressure on the back of the rotor blades is reduced and the pressure distribution is more uniform. Furthermore, compared to Figure (d) in Figure 5, which shows the simulation of Example 1, the pressure on the back of the rotor blades of the compressor CM is also reduced.

[0116] This demonstrates that setting a second groove on the basis of the first groove helps to further slow down the speed of gas flowing into and out of the back disk cavity through the first and second grooves, and can make some gas almost stagnate in the second groove, thereby reducing the amount of gas flowing into or out of the back disk cavity, thus making the pressure change in the back disk cavity more stable and reducing the back pressure acting on the turbine rotor blades as a whole.

[0117] [Example 4]

[0118] Figure 11 shows a simulation comparison between the existing design turbo compressor and the turbo compressor of Example 4 under the same inflow gas conditions.

[0119] The difference between Example 4 and Example 3 described above with reference to Figures 7 to 10 is that the first groove G1”' and the second groove G2' have essentially the same first depth and second depth, both being 2mm. The first width of the first groove G1”' and the second width of the second groove G2' are reduced to 1.5mm.

[0120] In the simulation comparison diagrams shown in Figure 11, (a) and (b) show the gas flow velocity cloud map comparison near the inlet I1; (c) and (d) show the gas pressure distribution cloud map comparison at the blade of the rotor CR of the compressor CM, at the airflow channel FP, and at a part of the back disk cavity BDC; (e) and (f) show the gas pressure distribution cloud map comparison near the inlet I1 where the airflow channel FP enters the first groove G1”’, the first groove G1”’ and the second groove G2’; (g) and (h) show the pressure distribution cloud map comparison on the back side of the same blade of the rotor CR of the compressor CM.

[0121] Comparing Figures (a) and (b) in Figure 11, it can be seen that after the gas flows into I1 from the gas flow channel FP through the inlet, the gas exhibits rotational motion around an axis perpendicular to the plane of the paper at the position indicated by N4 in the first groove G1”'. Then, at the position indicated by N5 in the second groove G2', there is a gas rotational motion at a lower speed (see the color indication in the left-hand cloud diagram), resembling a vortex motion. This indicates that a portion of the gas may be approximately stationary (with a speed close to zero) in the second groove G2'. Its rotational trajectory is more closely approximating rotational motion than that in Figure (b) of Figure 10.

[0122] Comparing Figures (c) and (e) with Figures (d) and (f) in Figure 11, it can be seen that the gas pressure in the back disk cavity BDC of the turbo compressor according to Example 4 is significantly lower than the pressure in the back disk cavity BDCx of the turbo compressor according to the prior art design.

[0123] Comparing Figure (g) and Figure (h) in Figure 11, it can be seen that the pressure on the back of the rotor blades is reduced and more uniform in Example 4.

[0124] This demonstrates that setting a second groove on the basis of the first groove helps to further slow down the speed of gas flowing into and out of the back disk cavity through the first and second grooves, and can make some gas almost stagnate in the second groove, thereby reducing the amount of gas flowing into or out of the back disk cavity, thus making the pressure change in the back disk cavity more stable and reducing the back pressure acting on the turbine rotor blades as a whole.

[0125] [Example 5]

[0126] Figure 12 shows a comparison of simulation results between the existing design and Embodiment 5 under the same inflow gas conditions. Figures (a) and (b) show a comparison of gas flow velocity cloud maps near inlet I1; Figures (c) and (d) show a comparison of gas pressure distribution cloud maps at the blades of the rotor CR of the compressor CM, the airflow channel FP, and a portion of the back disk cavity BDC; Figures (e) and (f) show a comparison of gas pressure distribution cloud maps near inlet I1 where the airflow channel FP enters the first groove G1””, the first groove G1””, and the second groove G2”; Figures (g) and (h) show a comparison of pressure distribution cloud maps on the back side of the same blade of the rotor CR of the compressor CM.

[0127] The difference between Example 5 and Example 4 described above with reference to FIG11 is that the first depth and the second depth of the first groove G1”” and the second groove G2” are increased to 2.5mm.

[0128] Comparing Figures (a) and (b) in Figure 12, it can be seen that after the gas flows into I1 from the gas flow channel FP through the inlet, the gas exhibits a rotational motion around an axis perpendicular to the plane of the paper at the position indicated by N6 in the first groove G1””. Furthermore, at the position indicated by N7 in the second groove G2”, there is still a gas rotational motion at a lower speed (see the color indication in the cloud diagram on the left). Thus, it can be concluded that a portion of the gas is approximately stationary in the second groove G2.

[0129] Comparing Figures (c) and (e) with Figures (d) and (f) in Figure 12, it can be seen that the gas pressure in the back disk cavity BDC of the turbo compressor according to Example 5 is significantly lower than the pressure in the back disk cavity BDCx of the turbo compressor according to the prior art design.

[0130] Comparing Figure (g) and Figure (h) in Figure 12, it can be seen that the pressure on the back of the rotor blades is reduced and more uniform in Example 5.

[0131] This demonstrates that setting a second groove on the basis of the first groove helps to further slow down the speed of gas flowing into and out of the back disk cavity through the first and second grooves, and can make some gas almost stagnate in the second groove, thereby reducing the amount of gas flowing into or out of the back disk cavity, thus making the pressure change in the back disk cavity more stable and reducing the back pressure acting on the turbine rotor blades as a whole.

[0132] [Example 6]

[0133] Figure 13 shows a comparison of simulation results between the existing design and Embodiment 6 under the same inflow gas conditions. Figures (a) and (b) show a comparison of gas flow velocity cloud maps near inlet I1; Figures (c) and (d) show a comparison of gas pressure distribution cloud maps at the blades of the rotor CR of the compressor CM, the airflow channel FP, and a portion of the back disk cavity BDC; Figures (e) and (f) show a comparison of gas pressure distribution cloud maps near inlet I1 where the airflow channel FP enters the first groove G1””’, the first groove G1””’, and the second groove G2”’; Figures (g) and (h) show a comparison of pressure distribution cloud maps on the back side of the same blade of the rotor CR of the compressor CM.

[0134] The difference between Embodiment 6 and Embodiment 4 described above with reference to Figures 7 to 10 is that the cross-sectional shape of the first groove G1””’ and the second groove G2”’ is composed of a rectangle and a sector segment circumscribed at the bottom of the rectangle.

[0135] In the illustrated embodiment, the first groove G1””’ has a first width of 2mm, and its outer arcuate segment is a semicircle with a diameter of 1mm. The second groove G2”” also has a second width of 2mm, but its second depth is shallower than the first depth of the first groove G1””’. Furthermore, the second groove G2”’ has an arcuate segment or fan-shaped segment with a chord length of 2mm circumferentially connected to its outer rectangular axis.

[0136] Comparing Figures (a) and (b) in Figure 13, it can be seen that after the gas flows into I1 from the gas flow channel FP through the inlet, the gas exhibits rotational motion around an axis perpendicular to the plane of the paper at the position indicated by N8 in the first groove G1””’, and then continues to flow at a lower speed (see the color indication in the cloud map on the left) at the position indicated by N9 in the second groove G2””’. In Figure 13(b), the velocity lines of the vortex motion at N8 are more dense, and it can be observed that a portion of the fluid flows along the bottom of the semi-circular groove of the first groove G1””’, and then flows into the second groove G2”’.

[0137] Comparing Figures (c) and (e) with Figures (d) and (f) in Figure 13, it can be seen that the gas pressure in the back disk cavity BDC of the turbo compressor according to Example 5 is significantly lower than the pressure in the back disk cavity BDCx of the turbo compressor according to the prior art.

[0138] This demonstrates that setting a second groove on the basis of the first groove helps to further slow down the speed of gas flowing into and out of the back disk cavity through the first and second grooves, and can make some gas almost stagnate in the second groove, thereby reducing the amount of gas flowing into or out of the back disk cavity, thus making the pressure change in the back disk cavity more stable and reducing the back pressure acting on the turbine rotor blades as a whole.

[0139] [Example 7]

[0140] Figure 14 shows a comparison of the simulation results of the existing design and Example 6 under the same inflow gas conditions, where (a) and (b) show a comparison of the gas flow velocity cloud maps near the inlet I1;

[0141] Figures (c) and (d) show a comparison of gas pressure distribution cloud maps at the blades of the rotor CR of the compressor CM, at the airflow passage FP, and at a portion of the back disk cavity BDC; Figures (e) and (f) show a comparison of gas pressure distribution cloud maps near the inlet I1 of the airflow passage FP leading to the first groove G1”””, the first groove G1”””, and the second groove G2””; Figures (g) and (h) show a comparison of pressure distribution cloud maps on the back side of the same blade of the rotor CR of the compressor CM.

[0142] The difference between Embodiment 7 and Embodiment 3 described above with reference to Figures 7 to 10 is that the cross-sectional shapes of the first groove G1””” and the second groove G2”” are not rectangular shapes with bottom chamfers, but approximately quadrilateral shapes formed by a 2mm width feed. Each of the first and second grooves has two edges parallel to the axial direction A in the cross-section, an arc transition portion transitioning from one edge to the bottom of the groove, and an arc transition portion starting from the other edge for tool retraction. Taking the first groove G1””” as an example, as shown in Figure 14(f), it has arc transition portions t1 and t2 at its two edges respectively.

[0143] In Example 7, the width of the main body portion of the cross-section of the first groove G1””” and the second groove G2”” is 2mm.

[0144] Comparing Figures (a) and (b) in Figure 13, it can be seen that after the gas flows from the gas flow channel FP into the first groove G1”” through the inlet I1, the gas exhibits a rotational motion around an axis perpendicular to the plane of the paper at the position indicated by N10 in the first groove G1””, with a relatively large radius of rotation, close to the bottom of the first groove G1””. Subsequently, the gas exhibits a rotational motion around almost the entire sidewall of the second groove G2”” at the position indicated by N11 in the second groove G2”” at a lower speed (see the color indication in the left-hand cloud diagram).

[0145] Comparing Figures (g) and (h) in Figure 13, it can be seen that in the turbo compressor according to Embodiment 7, the area with less back pressure on the blades of the rotor CR of the compressor CM, i.e. the area marked in blue in the figure, is increased compared to the existing design of the turbo compressor.

[0146] This demonstrates that setting a second groove G2"' on the basis of the first groove G1""' helps to further slow down the velocity of the gas flowing into and out of the back disk cavity BDC through the first groove G1""' and the second groove G2"', and can make a part of the gas move in an approximate vortex motion in the second groove G2"', and may quasi-stagnate in the second groove G2"', and can also expand the range of the area of ​​the rotor CR blades of the turbine CM that is subjected to lower back pressure.

[0147] Regarding the embodiments 1-7 above, it has been demonstrated that when at least one groove is provided in the intermediate body of the turbo compressor, especially when the first groove and the second groove as described above are provided simultaneously, the gas flow in the airflow channel-first groove-(second groove-)back plate cavity circuit can be guided, the amount of gas flowing into or out of the back plate cavity can be reduced, and the pressure distribution in the circuit, especially in the back plate cavity, can be improved.

[0148] Furthermore, the pressure on the back side of the rotor impeller blades on the compressor side of the turbo compressor can be reduced, and the increase in thrust load on the turbine compressor shaft during transients can be delayed, thereby delaying the increase in pressure on the back plate side of the compressor during transients.

[0149] Furthermore, the present invention also reduces the thrust load on the turbine compressor axle in steady state, thereby reducing the pressure on the backplate side in steady state.

[0150] The overall operating efficiency of the turbo compressor according to the present invention can be improved, and synchronous noise reduction is achieved at the turbine shaft of the turbo compressor.

[0151] The grooved intermediate body of the turbo compressor according to the present invention can be obtained by further machining on the intermediate body of an existing turbo compressor. The machining process is simple, low in cost, and does not require additional parts.

[0152] Furthermore, in the above embodiments 1 to 7, the radius of the chamfer at the bottom of the rectangular cross-section when the first or second groove is constructed to have a rectangular cross-section was described, but the present invention is not limited thereto, and the bottom of the rectangular cross-section may have a chamfer radius greater than 0.5 mm.

[0153] Furthermore, in the above embodiments 1 to 7, the shape of the groove in the longitudinal section of the turbo compressor is described as rectangular, approximately quadrilateral, or a rectangular circumcircle segment. However, the present invention is not limited to this. The shape that allows the fluid to undergo vortex motion can be the cross-sectional shape of the first groove and / or the second groove, including having a certain solid shape in the cross-section, so that the gas rotates around the solid in the cross-section. The effect is still similar to the above-mentioned vortex motion.

[0154] Furthermore, in embodiments 3 to 7 above, the second groove is implemented as a ring extending 360° around the axis of the compressor turbine's axle. However, the present invention is not limited to this. The second groove may also be similar to the first groove in embodiment 2, constructed as one or more second grooves extending an arc segment in the circumferential direction around the axis of the axle.

[0155] Furthermore, in embodiments 3 to 7 described above, the first and second grooves are described as being located on the compressor-facing side of the intermediate body of the turbo compressor. However, the present invention is not limited to this, but can also be applied to turbines in turbo compressors, individual air compressors, single turbines, and other rotating machines with rotating rotors that require control of the blade back pressure. In the latter case, the gas guide portion of the groove is, for example, located on the housing sidewall behind the rotor blades, not extending radially beyond the outermost radial position of the rotor blades.

[0156] List of reference numerals: A Axial direction AX Wheel shaft BD, BDx Back plate BDC, BDCx Back plate cavity BDS Back plate back side CH Intermediate body CM Compressor CMH Compressor housing CR, CRx Compressor rotor FP Airflow passage G1, G1', G1”, G1”’, G1””, G1””, G1”” First groove G1D, G1”D First depth G1W, G1”W First width G2, G2', G2”, G2”’, G2”” Second groove G2D Second depth G2W Second width I1 (Gas guide) inlet IL (Compressor) inlet P1, P1x Blade side gas pressure; P2, P2x Wheel back gas pressure; R Recess RB Recess bottom RE (Recess) radial edge RW Recess wall S1 (Intermediate body) side S2 (Compressor housing) side t1, t2 Arc transition SPA Sealing plate assembly SR Turbine sealing ring™, turbine TMH, turbine housing TR, turbine rotor 1000x (prior art), turbo compressor 1000, 1000' turbo compressor

Claims

1. A rotating machine, comprising: The housing includes a first housing portion and a second housing portion, the first housing portion and the second housing portion being arranged adjacent to each other along the axial direction of the rotating machine and forming an airflow channel between them, the second housing portion having a recess on its side facing the first housing portion; The rotor is housed in the housing and includes a rotor impeller that rotates about a rotor axis. The rotor impeller includes a plurality of rotor blades and is configured to exchange the pressure of an airflow passing through the rotor blades with the rotational kinetic energy of the rotor. The airflow can flow through the airflow passage. A back disk, which is axially positioned opposite the back surfaces of the plurality of rotor blades, is received within a recess in the second housing portion, the recess and the back disk defining a back disk cavity. A gas guide is provided in the recessed portion so that the airflow channel and the back plate cavity can be fluidly connected through the gas guide, and the gas guide is configured to allow the gas to move in a vortex within the gas guide.

2. The rotating machine as described in claim 1, characterized in that, The gas guide portion is configured to include at least one groove, the at least one groove being configured to extend axially away from the back plate from the bottom of the recess, wherein the at least one groove extends at an angle in the circumferential direction about the rotor axis, and wherein the at least one groove includes a first groove that extends at a first angle in the circumferential direction about the rotor axis and has a first depth.

3. The rotating machine as described in claim 2, characterized in that, The gas guide includes a plurality of independent first grooves, wherein the sum of the first angles of each of the plurality of first grooves is less than 360°.

4. The rotating machine as described in claim 3, characterized in that, The first angles of each of the plurality of first grooves are equal to each other, and the plurality of first grooves are evenly spaced apart in the circumferential direction.

5. The rotating machine as described in claim 2, characterized in that, The gas guide includes a first groove, the first angle of the first groove being 360°.

6. The rotating machine as described in claim 5, characterized in that, The gas guide further includes at least one second groove, which is radially spaced from the first groove and disposed radially inside the first groove. The second groove has a second depth and is configured such that gas entering the gas guide can pass through the first groove and the second groove successively.

7. The rotating machine as claimed in claim 6, characterized in that, The first groove is located at the outermost radial edge of the recess.

8. The rotating machine as claimed in claim 6, characterized in that, The second depth is equal to or less than the first depth.

9. The rotating machine as claimed in any one of claims 2 to 8, characterized in that, The first depth is 2mm.

10. The rotating machine as claimed in any one of claims 2 to 8, characterized in that, The at least one groove has a groove width, which ranges from 1.5 to 2.5 mm.

11. The rotating machine as claimed in any one of claims 2 to 8, characterized in that, When viewed in a longitudinal section of the rotating machine, the cross-section of the at least one groove has any of the following shapes: Includes a rectangle and an arcuate segment axially outside the rectangle, wherein the arcuate segment is further away from the back plate than the rectangle; or Includes a rectangle, wherein the rectangle has a chamfer at its bottom edge.

12. The rotating machine as claimed in claim 11, characterized in that, The radius of the chamfer is between 0.5 and 1.0 mm.

13. The rotating machine as claimed in any one of claims 2 to 8, characterized in that, The rotating machine is configured such that gas entering the rotating machine passes through the rotor blades and flows into the airflow channel.

14. A turbo compressor, comprising: A compressor with a housing, an intermediate body, a turbine with a housing, and a wheel axle. The compressor impeller of the compressor and the turbine impeller of the turbine are respectively located at two ends of the shaft. The intermediate body is disposed around the axle between the compressor and the turbine, and engages with the housing of the compressor and the housing of the turbine. Wherein, the compressor or the turbine is a rotating machine constructed as described in any one of claims 1 to 13, the housing of the compressor or the housing of the turbine constitutes the first housing portion, and the intermediate body constitutes the second housing portion.

Images