Scroll pump
By adding a channel on the stationary scroll to create an additional fluid flow path, the inlet conductance of scroll pumps is increased, enhancing their pumping capacity.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-22
- Publication Date
- 2026-03-19
AI Technical Summary
Scroll pumps have a high aspect ratio in their pump chambers, leading to a limited fluid flow and reduced inlet conductance, which restricts their pumping capacity.
Incorporating a channel or groove on the base of the stationary scroll that provides an additional fluid flow path perpendicular to the main flow path, increasing inlet conductance without significantly affecting the pumping capacity.
Enhances fluid flow into the pump chambers by providing an additional flow path, thereby improving the inlet conductance and overall pumping capacity of the scroll pump.
Smart Images
Figure 2026509548000001_ABST
Abstract
Description
Technical Field
[0001] The field of the present invention relates to scroll pumps. Exemplary embodiments relate to scroll pumps with increased inlet conductance.
Background Art
[0002] A scroll pump includes fixedly arranged and orbiting scrolls that are arranged alternately and attached to obtain relative orbiting motion. The base and involute wall of the scrolls define a pump chamber that transfers fluid from the inlet of the pump to the outlet of the pump. Usually, the inlet is located on the peripheral portion of the scroll pump. For example, the inlet may be located on the peripheral portion of the fixed scroll. Usually, the outlet is located in the central portion of the pump. For example, the outlet can be in the form of a port located at the center of the base of one of the scroll members.
[0003] The pump chamber can adopt an open configuration that receives fluid from the inlet along the flow path. Due to the orbiting motion of the orbiting scroll relative to the fixed scroll, the pump chamber is gradually isolated from the inlet and finally reaches a closed state where it is substantially completely isolated from the inlet. As the orbiting motion further progresses, the closed pump chamber moves towards the outlet along a spiral path and gradually decreases in size to compress the fluid confined within the pump chamber. Finally, the pump chamber becomes in fluid communication with the outlet, and the compressed fluid can be discharged from the pump chamber.
[0004] In the open configuration, fluid can enter the pump chamber from the inlet through the open end of the pump chamber located between the involute wall of the fixed scroll and the involute wall of the orbiting scroll. Therefore, the flow path of the fluid flowing from the inlet into the pump chamber extends substantially parallel to the base of the scroll member.
[0005] Scroll pump chambers tend to have a very high aspect ratio. In other words, the pump chamber is relatively long, while its width and height are relatively short, and the open end of the pump chamber tends to have a relatively small cross-sectional area. This can limit the fluid flow into the pump chamber and, therefore, the inlet conductance of the pump, which can be a factor limiting the pump's pumping capacity. [Overview of the Initiative] [Problems that the invention aims to solve]
[0006] It is desirable to be able to increase the inlet conductance of the scroll pump. [Means for solving the problem]
[0007] This invention provides a scroll pump, and the scroll pump is An inlet for receiving the fluid being pumped in, An outlet for transferring the fluid supplied by the pump from the scroll pump, Two scroll members comprising a fixed scroll and an orbiting scroll, Equipped with, The orbiting scrolls are arranged alternately with the stationary scrolls, and are mounted such that the rotation of a motor imparts orbital motion to the orbiting scrolls relative to the stationary scrolls. Each scroll member has a base from which an involute wall extends, defining a pump chamber for transferring fluid from an inlet to an outlet. As the orbiting scrolls move, the pump chamber transitions from an open configuration, where it receives fluid from the inlet along a first flow path, to a closed configuration, where it is substantially isolated from the inlet. The base of one of the scroll members includes a channel that communicates with the inlet, and when the pump chamber is in the open configuration, it is positioned to receive fluid from the inlet along an additional flow path through the channel.
[0008] This channel, at least partially, defines an additional flow path for fluid to enter the pump chamber when the pump chamber is in an open configuration, and thus can increase the inlet conductance of the pump.
[0009] Preferably, the inlet extends through the circumferential outer wall of the stationary scroll. Preferably, the first fluid passage is arranged to transfer fluid from the inlet to the pump chamber between the involute wall of the stationary scroll and one end of the involute wall of the revolving scroll. Preferably, the first fluid passage extends substantially parallel to the base of the scroll member. The area of the opening between the involute walls of the scroll member through which the fluid flowing along the first passage enters the pump chamber decreases as the pump chamber moves toward a closed configuration, and therefore the flow rate of the fluid along the first passage changes as the relative position of the scroll member changes.
[0010] Preferably, the channel is located adjacent to the inlet of the scroll pump. This results in an additional flow path that is relatively short with respect to the incoming fluid. If the channel is located far from the inlet, a longer fluid flow path is required, which reduces conductance.
[0011] Preferably, the channel is elongated in shape to maximize the area through which the fluid passing through the additional passage can enter the pump chamber, and preferably partially extends around the axis of orbital movement of the revolving scroll relative to the stationary scroll. This allows the range of orbital movement over which the channel communicates with the pump chamber is increased. Preferably, the channel extends around this axis by an angle in the range of 10 to 60 degrees, preferably in the range of 15 to 30 degrees.
[0012] The channels are arranged so that the additional flow path transfers fluid into the pump chamber between the involute walls of the scroll member, preferably in a direction substantially perpendicular to the base of the scroll member. Thus, the area of the flow path through which the fluid enters the pump chamber decreases as the pump chamber moves toward its closed configuration, and therefore the flow rate of the fluid through the additional flow path also changes as the relative position of the scroll member changes.
[0013] Preferably, the direction in which the fluid enters the pump chamber from the channel is substantially perpendicular to the direction in which the fluid enters the pump chamber directly from the inlet.
[0014] Preferably, the channel is shaped such that, in an open configuration, the channel is in fluid communication with the pump chamber, and in a closed configuration, it is substantially isolated from the pump chamber. The channel can be positioned so that the open fluid communication between the channel and the pump chamber is synchronized with the open fluid communication between the inlet and the pump chamber. In this way, the inlet conductance can be increased without excessively adversely affecting the pumping capacity of the scroll pump by providing an additional fluid passage to the pump chamber in the open configuration.
[0015] Preferably, the channel is completely isolated from the pump chamber when the pump chamber is in a closed configuration, i.e., when there is a minimal or no gap between the involute walls of the stationary scroll and the involute walls of the orbiting scroll at both ends of the pump chamber. While a scroll pump may have such synchronization between the open fluid communication between the channel and the pump chamber and between the inlet and the pump chamber, it should be noted that even a slight delay in this synchronization can provide an effective and improved pump. For example, the channel may become isolated from the pump chamber before the pump chamber is completely isolated from the inlet.
[0016] The channel can be located at the base of a stationary scroll, or at the base of an orbiting scroll. In the latter case, the channel moves relative to the stationary scroll due to the relative orbital motion of the scroll members. This allows the channel to move by orbital motion from a first position where substantially the entire channel allows fluid to enter the pump chamber along an additional passage when the pump chamber inlet is fully open, i.e., when there is the maximum gap between the involute wall of the stationary scroll defining the pump chamber and the end wall of the involute wall of the orbiting scroll, to a second position where the pump chamber inlet is closed and substantially prevents fluid from entering the pump chamber along an additional passage.
[0017] As a further alternative, the first channel can be located at the base of the fixed scroll and the second channel at the base of the revolving scroll. This allows for the establishment of a second additional flow path between the inlet and the pump chamber in an open configuration, further improving conductance.
[0018] The channel can be configured to be at least partially hidden from the pump chamber when the pump chamber is in an open configuration. The degree to which the channel is hidden from the pump chamber preferably changes as the relative position of the scroll member changes.
[0019] The channel can transfer fluid from the inlet to the outermost pump chamber of the scroll pump. For example, the channel can be located at the base of a stationary scroll, adjacent to the outer circumferential wall of the stationary scroll. This wall can be the wall of the scroll pump housing. Alternatively, the channel can be located on the outer circumferential flange at the base of an orbiting scroll.
[0020] A scroll pump can have a plurality of pump chambers. For example, they can be present one on each side of the involute wall of the scroll. Each of these two pump chambers can be made in an open configuration such that each receives fluid along two respective flow paths, where one directly transfers fluid from the inlet to the pump chamber and the other transfers fluid from the inlet to the pump chamber via a channel. When one of these two pump chambers is in a closed configuration, the other of these two pump chambers is preferably in a fully open configuration. In some embodiments, the channel can move across the intervening involute wall by the relative orbiting motion between the scroll members.
[0021] The channel can be partitioned along its length by a strip extending from one side to the other side. This can provide support for the tip seal provided at the end of the involute wall facing the channel.
[0022] A scroll pump can have a plurality of the above channels to increase the fluid conductance to each pump chamber.
[0023] A scroll pump can be a multi-start scroll pump with a plurality of inlets, and this scroll pump includes a plurality of the above channels each arranged adjacent to a respective inlet.
[0024] A scroll pump can be in the form of a scroll vacuum pump.
[0025] The orbiting scroll refers to the scroll that orbits during the use of the scroll. It should be understood that when the pump is not in use, the orbiting scroll does not move by itself.
[0026] Next, the preferred features of the present invention will be further described with reference to the accompanying drawings.
Brief Description of the Drawings
[0027] [Figure 1] Schematically shows a top cross-sectional view of the inlet portion of a known scroll pump. [Figure 2] It is a side cross-sectional view taken along line A-A of FIG. 1. [Figure 3] It is a top cross-sectional view of the inlet portion of one embodiment of a scroll pump [Figure 4] It is a side cross-sectional view taken along line B-B of FIG. 3. [Figure 5] Shows the inlet portion of the scroll pump of FIG. 3 at different points in the pump's revolution cycle. [Figure 6] Shows the inlet portion of the scroll pump of FIG. 3 at different points in the pump's revolution cycle. [Figure 7] Shows the inlet portion of the scroll pump of FIG. 3 at different points in the pump's revolution cycle. [Figure 8] Shows the inlet portion of the scroll pump of FIG. 3 at different points in the pump's revolution cycle.
MODE FOR CARRYING OUT THE INVENTION
[0028] FIGS. 1 and 2 show schematic cross-sectional views of the inlet portion of a conventional scroll pump 10. The scroll pump 10 includes two scroll members in the form of a fixed scroll 12 and a revolving scroll 14. The revolving scroll 14 is driven by a motor (not shown) and revolves around a revolving axis offset from the center of the fixed scroll 12 with respect to the fixed scroll 12. The fixed scroll 12 includes a base 16 and an involute (or spiral) wall 18 rising from the base 16 and perpendicular thereto. Similarly, the revolving scroll 14 includes a base 20 and an involute (or spiral) wall 22 rising from the base 22 and perpendicular thereto. The bases 16, 18 and the involute walls 20, 22 of the scroll members, together with the outer peripheral wall 24 of the fixed scroll 12, define a plurality of pump chambers, generally indicated at 26 therebetween.
[0029] Depending on the relative positions of the fixed scroll 12 and the revolving scroll 14, the pump chamber 26 is configured to adopt either an open configuration in which the pump chamber is in fluid communication with the inlet 28 of the scroll pump 10, or a closed configuration in which the pump chamber is isolated from the inlet 28. The inlet 28 extends through the outer wall 24 of the fixed scroll 12. In the relative positional relationship of the fixed scroll 12 and the revolving scroll 14 shown in Figure 1, the first pump chamber 30 and the second pump chamber 32 are in an open configuration, and the fluid can enter the first pump chamber 30 from the inlet 28 along a first flow path indicated as F1 as a whole, and enter the second pump chamber 32 from the inlet 28 along a second flow path indicated as F2 as a whole. Each of the first flow path F1 and the second flow path F2 extends parallel to the bases 16 and 18 of the scroll members.
[0030] As the revolving scroll 14 revolves around the stationary scroll 12, each of the first pump chamber 30 and the second pump chamber 32 moves into a closed configuration, resulting in the pump chamber being isolated from the inlet 28. Further revolving motion causes the closed pump chambers to move inward along a spiral path toward the central outlet (not shown) of the scroll pump 10, gradually decreasing in size to compress the fluid trapped inside. Eventually, each pump chamber becomes fluid-connected to the outlet, allowing the compressed fluid to be released from the scroll pump 10.
[0031] When the first pump chamber 30 is open, the fluid enters the first pump chamber 30 from its open end, which is located between the involute wall 18 of the fixed scroll 12 and the involute wall 22 of the revolving scroll 14. When the second pump chamber 32 is open, the fluid enters the second pump chamber 32 from its open end, which is located between the outer wall 24 of the fixed scroll 12 and the involute wall 22 of the revolving scroll 14. The open ends of the pump chambers tend to have relatively small cross-sectional areas. This can limit the fluid flow into the pump chambers.
[0032] Figures 3 and 4 show schematic cross-sectional views of the inlet portion of one embodiment of the scroll pump 10'. Features of the scroll pump 10' that are identical to those of the scroll pump 10 are indicated using the same reference numerals and are therefore omitted from further explanation. The scroll pump 10' differs from the scroll pump 10 in that the base 16 of the fixed scroll 12 is provided with a channel (groove) 34 in the form of a notch formed in the base 16. The channel 34 is in fluid communication with the inlet 28. The channel 34 is located adjacent to the inlet 28 and extends partially longitudinally around the axis on which the revolving scroll 14 moves relative to the fixed scroll 12.
[0033] As detailed below, channel 34 is positioned on the fixed scroll 12 and can establish an additional flow path F3 between the inlet 28 and the pump chamber in an open configuration. Referring to Figure 4, in the illustrated relative positions of the fixed scroll 12 and the revolving scroll 14, the additional flow path F3 extends from the inlet 28 through channel 34 to the first pump chamber 30. The fluid enters the first pump chamber 30 from channel 34 in a direction perpendicular to the bases 16, 20 of the scroll members and parallel to the longitudinal axis of the scroll pump 10'. Thus, the fluid enters the first pump chamber 30 from channel 34 (along the additional flow path F3) in a direction perpendicular to the direction in which the fluid enters the first pump chamber 30 directly from the inlet 28 (along the first flow path F1). By positioning channel 34 adjacent to the inlet 28, the length of the additional flow path F3 can be minimized, and therefore the conductance of the scroll pump 10' can be further improved.
[0034] Figures 5 to 8 show how the first pump chamber 30 is isolated from the channel 34 as it moves toward a closed configuration isolated from the inlet 28. In these figures, the orbiting scroll 14 is shown in a series of different positions relative to the fixed scroll 12, as occurs when the orbiting scroll 14 orbits the fixed scroll 12 during the use of the scroll pump 10'.
[0035] At the position of the orbiting scroll 14 shown in Figure 5, the first pump chamber 30 is in a completely open configuration, and the radial distance between the end 36 of the involute wall 22 of the orbiting scroll and the involute wall 18 of the stationary scroll 12 is at its maximum. At this position, the area of the outlet 38 of the channel 34, which is in fluid communication with the first pump chamber 30, is also at its maximum. The first portion of the fluid entering the scroll pump 10' enters the first pump chamber 30 from the inlet 28 along the first flow path F1, while the second portion of the fluid entering the scroll pump 10' enters the first pump chamber 30 from the inlet 28 along an additional flow path F3. At this position of the orbiting scroll, the radially outermost pump chamber 40 is in a closed configuration and is isolated from both the inlet 28 and the channel 34 by the involute wall 22 of the orbiting scroll 14.
[0036] Figure 6 shows the position of the orbital scroll 14 relative to the stationary scroll 12 after it has revolved 30 degrees from the position shown in Figure 5. The second pump chamber 32 is established between the involute wall 22 of the orbital scroll 14 and the outer wall 24 of the stationary scroll 12. Both the first pump chamber 30 and the second pump chamber 32 are open configurations. The first pump chamber 30 remains in fluid communication with the inlet 28 via the first flow path F1 and an additional flow path F3, but the size of both of these flow paths is reduced in terms of the movement of the orbital scroll 14 relative to the stationary scroll. The second pump chamber 32 is in fluid communication with the inlet 28 via the second flow path F2.
[0037] Figure 7 shows the position of the orbital scroll 14 relative to the stationary scroll 12 after it has revolved 90 degrees from the position shown in Figure 6. The first pump chamber 30 remains open, but because the first pump chamber 30 is substantially isolated from the channel 34 by the involute wall 22 of the orbital scroll 14, the fluid enters the first pump chamber 30 substantially only through the first flow path F1 (however, some fluid may leak from the channel 34 into the first pump chamber 30 from below the involute wall 22). The second pump chamber 32, on the other hand, remains open, but the fluid now enters the second pump chamber through both the second flow path F2 and an additional flow path F3.
[0038] Figure 8 shows the position of the orbital scroll 14 relative to the stationary scroll 12 after it has revolved 30 degrees from the position shown in Figure 7. The first pump chamber 30 is a closed configuration, completely isolated from the inlet 28 by the involute wall 22 of the orbital scroll 14. The second pump chamber 32 remains an open configuration, but the amount of fluid flowing into the second pump chamber through both the second flow path F2 and the additional flow path F3 increases.
[0039] Therefore, in this embodiment, the first pump chamber 30 transitions from a fully open configuration to a closed configuration after the revolving scroll 14 has revolved 150 degrees relative to the fixed scroll 12. [Explanation of symbols]
[0040] 10 Scroll Pumps 10' Scroll Pump 12 Fixed Scroll 14 Orbital Scroll 16 base 18 Involute Walls 20 base 22 Involute Walls 24 Exterior Wall 26 Pump Room 28 Entrance 30. First pump room 32. Second Pump Room 34 channels 36 Involute wall end 38 Channel Exit 40. Outermost pump room F1 First channel F2 Second channel F3 Additional channel
Claims
1. It is a scroll pump, An inlet for receiving the fluid being pumped in, An outlet for transferring the fluid supplied by the pump from the scroll pump, Two scroll members comprising a fixed scroll and an orbiting scroll, Equipped with, The orbiting scrolls are arranged alternately with the stationary scrolls and are mounted such that the rotation of a motor imparts orbital motion to the orbiting scrolls relative to the stationary scrolls, each of the scroll members having a base from which an involute wall extends to define a pump chamber for transferring fluid from the inlet to the outlet, and as the orbital movement of the orbiting scrolls, the pump chamber transitions from an open configuration in which the pump chamber receives fluid from the inlet along a first flow path to a closed configuration in which the pump chamber is substantially isolated from the inlet. A scroll pump in which the base of one of the scroll members includes a channel that is in fluid communication with the inlet, the channel being arranged so that the pump chamber receives fluid from the inlet along an additional flow path through the channel when the pump chamber is in an open configuration.
2. The scroll pump according to claim 1, wherein the first fluid passage is arranged to transfer fluid from the inlet to the pump chamber between the involute wall of the stationary scroll and one end of the involute wall of the orbiting scroll.
3. The scroll pump according to claim 1 or 2, wherein the first fluid passage extends substantially parallel to the base of the scroll member.
4. The scroll pump according to any one of claims 1 to 3, wherein the channel is located adjacent to the inlet.
5. The scroll pump according to any one of claims 1 to 4, wherein the channel has an elongated shape and partially extends longitudinally around the axis of revolving movement of the revolving scroll relative to the fixed scroll.
6. The scroll pump according to claim 5, wherein the channel extends around the axis by an angle in the range of 10 to 60 degrees, preferably in the range of 15 to 30 degrees.
7. The scroll pump according to any one of claims 1 to 6, wherein the additional flow path is arranged to transfer fluid into the pump chamber in a direction substantially perpendicular to the base of the scroll member.
8. The scroll pump according to any one of claims 1 to 7, wherein the direction in which the fluid enters the pump chamber from the channel is substantially perpendicular to the direction in which the fluid enters the pump chamber directly from the inlet.
9. The scroll pump according to any one of claims 1 to 8, wherein the channel is shaped such that, in an open configuration, the channel is in fluid communication with the pump chamber, and in a closed configuration, the channel is substantially isolated from the pump chamber.
10. A scroll pump according to any one of claims 1 to 9, comprising a plurality of pump chambers, wherein the channels are arranged to transfer fluid from the inlet to the outermost pump chamber.
11. The scroll pump according to any one of claims 1 to 10, wherein the channel is arranged to simultaneously transfer fluid to two pump chambers, each having an open configuration.
12. The scroll pump according to claim 11, wherein the channel is arranged to transfer fluid only to the other of the two pump chambers when one of the two pump chambers is in a closed position.
13. The scroll pump according to any one of claims 1 to 12, wherein the channel is located at the base of the fixed scroll.
14. The scroll pump according to any one of claims 1 to 12, wherein the channel is located at the base of the orbiting scroll.
15. A scroll pump according to any one of claims 1 to 12, comprising a first channel in the base of the fixed scroll and a second channel disposed in the base of the revolving scroll.