Triple screw pump and conveying system having the same

Abstract

The utility model relates to the technical field of screw pump, more specifically to the three screw pump of sealing structure wear condition visualization and the transmission system with the pump. Three screw pumps include the pump shell, its surface forms the sealing installation groove, and the inside forms the stream channel, the sealing installation groove is equipped with the insertion hole channel intercommunication with the stream channel, the stream channel is equipped with: rotatable drive screw and the driven screw that rotates along with this drive screw, the one end of drive screw extends the transmission shaft department outwardly and forms, the transmission shaft department passes through the insertion hole channel and is connected with the power device, the sealing installation groove still is provided with: the sealing structure that fills the gap between the outer periphery of transmission shaft department and the side wall of sealing installation groove, the sealing structure divides the inside space of sealing installation groove into: first cavity and the second cavity that communicate with the insertion hole channel, the pump shell still is provided with the leak detection flow channel that is inclined extension, and the upper end opening of leak detection flow channel is connected with first cavity intercommunication, and the lower end opening is open setting.

Description

Technical Field

[0001] This utility model relates to the field of screw pump technology, and more specifically to a three-screw pump that visualizes the wear of the sealing structure, and a transmission system having the pump. Background Technology

[0002] A three-screw pump is a typical rotary positive displacement pump, mainly consisting of a pump casing and a transfer unit housed within the casing. The transfer unit typically comprises a screw pair (one driving screw and two driven screws) working in conjunction with the inner wall of the pump casing. By setting appropriate gaps between the screws and between the screws and the inner wall of the pump casing, and utilizing the volume change of the sealed chamber formed by the meshing of the three screws as they rotate, the liquid can be continuously transported along the screw axis and ultimately stably delivered to the dosing point via the outlet.

[0003] In specific installation structures, one end of the drive screw, which provides rotational force, typically extends through the pump casing and is connected to the motor that provides rotational power. Therefore, to prevent material from flowing out of the pump casing, a sealing structure (such as a standard sealing ring or a mechanical seal consisting of a rotating and stationary ring) is usually installed around the drive screw to prevent material leakage. During long-term use, this sealing structure is prone to wear, and existing three-screw pumps often struggle to assess this wear, leading to frequent operational malfunctions, damage, and even excessive material leakage due to prolonged and excessive wear of the sealing structure. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a three-screw pump that can detect excessive wear of the sealing structure more promptly, thereby better mitigating the adverse effects caused by excessive wear of the sealing structure.

[0005] The overall technical solution of this utility model is as follows:

[0006] This invention addresses the problem that assessing the wear condition of the active screw seal structure in existing three-screw pumps is difficult, which can easily lead to adverse effects (operational malfunctions, damage, or even excessive material leakage). Specifically, the active screw seal structure is often located in the area between the motor and the pump housing, and this area often houses the transmission structure between the motor and the active screw, as well as some bearing structures, making it difficult to observe and assess the wear condition of the active screw seal structure.

[0007] Based on this, this utility model, based on research into the structure of existing three-screw pumps, proposes a three-screw pump that can more promptly detect excessive wear of the sealing structure. Specifically, the three-screw pump includes a pump casing with a sealing mounting groove formed on its surface and a material flow channel formed inside, having an inlet at one end and an outlet at the other end.

[0008] The bottom wall of the sealing installation groove is provided with an insertion channel that communicates with the logistics channel;

[0009] The logistics channel is equipped with a screw assembly that transports materials from the inlet to the outlet, which includes: a rotatable driving screw and two driven screws that rotate with the driving screw;

[0010] One end of the drive screw extends outward to form a drive shaft portion, which passes through the insertion hole and is connected to a power device that provides rotational force to the drive screw.

[0011] The sealing mounting groove is also equipped with a sealing structure that fills the gap between the outer periphery of the drive shaft and the side wall of the sealing mounting groove.

[0012] The sealing structure divides the internal space of the sealing mounting groove into: a first cavity and a second cavity communicating with the insertion channel;

[0013] The pump casing is also provided with an inclined leak detection channel. The upper opening of the leak detection channel is connected to the first cavity, and the lower opening is open.

[0014] An inclined leak detection channel is incorporated into the sealing structure, with its upper opening connected to the space on the side of the sealing structure opposite to the insertion hole. This allows the leak detection channel to flow outwards when the sealing structure becomes excessively worn and damaged, causing material to flow into the first cavity. This serves as a warning. The presence of material flowing out of the leak detection channel indicates excessive wear of the sealing structure, enabling timely and rapid maintenance and mitigating the adverse effects of such wear.

[0015] In some embodiments, the sealing structure includes:

[0016] The shaft seal sleeve, which is fixed in the sealing mounting groove and fitted onto the drive shaft, has an annular groove arranged around the drive shaft on the side facing the insertion hole.

[0017] The first sealing ring is fitted onto the shaft seal sleeve and fills the gap between the outer circumference of the shaft seal sleeve and the side wall of the sealing mounting groove;

[0018] A flexible stationary ring is fitted onto the drive shaft and has a portion that is positioned and accommodated in an annular groove.

[0019] The pushing assembly, located between the bottom wall of the sealing mounting groove and the stationary ring, is configured to apply a thrust to the stationary ring to drive it to fill the gap between the shaft sleeve and the drive shaft portion.

[0020] In some embodiments, the pushing assembly includes:

[0021] A rotating ring is placed between the bottom wall of the sealing mounting groove and the stationary ring, and is fitted onto the drive shaft. The rotating ring and the stationary ring are aligned in the axial direction of the drive shaft.

[0022] A mounting base placed between the bottom wall of the sealing mounting groove and the stationary ring, and rotating synchronously with the drive shaft.

[0023] A resilient pusher is positioned in a compressed manner between the mounting base and the moving ring to apply a thrust to the stationary ring, causing the stationary ring to change shape.

[0024] In some embodiments, the outer surface of the shaft seal sleeve is formed with a first sealing mounting groove, which is an annular groove with an outward opening and arranged around the drive shaft portion;

[0025] The first sealing ring is fitted into the first sealing mounting groove.

[0026] In some embodiments, the side of the shaft seal sleeve facing away from the insertion channel is formed with a sleeve wall extending around the drive shaft portion.

[0027] A bearing is fitted onto the drive shaft section, which is placed between the sleeve wall and the drive shaft section and supports the rotation of the drive shaft section.

[0028] In the axial direction of the drive shaft, the sleeve wall has a portion placed between the bearing and the stationary ring. This portion is provided with an outflow channel, one end of which is connected to the internal space of the sleeve wall, and the other end is connected to the upper opening of the leak detection channel.

[0029] In some embodiments, the outer periphery of the sleeve wall is provided with a discharge notch, which is an annular notch with an outward opening and arranged around the drive shaft portion;

[0030] In the axial direction of the drive shaft, the discharge notch is located on the side of the first sealing ring facing away from the insertion channel;

[0031] Furthermore, the other end of the outflow channel is connected to the upper opening of the leak detection channel through the discharge notch.

[0032] In some embodiments, the sleeve wall is provided with a plurality of outflow channels, which are arranged at intervals around the drive shaft portion.

[0033] In some embodiments, a second sealing mounting groove is formed on the outer surface of the shaft seal sleeve, which is an annular groove with an outward opening and arranged around the drive shaft portion;

[0034] In the axial direction of the drive shaft, the second sealing mounting groove is located on the side of the discharge notch facing away from the insertion channel;

[0035] Furthermore, the second sealing mounting groove is fitted with a second sealing ring that fills the gap between the outer periphery of the shaft sleeve and the side wall of the sealing mounting groove.

[0036] The transmission system includes the three-screw pump described in any of the above schemes.

[0037] In some implementations, the transmission system further includes:

[0038] Storage box, which has a material-containing cavity for holding transported materials;

[0039] The conveying pipe has one end connected to the material receiving chamber and the other end connected to the feed inlet, so as to guide the material in the material receiving chamber to the feed inlet.

[0040] The return pipe has one end connected to the lower opening of the leak detection channel, and the other end positioned above the material receiving chamber, so that the material flowing into the leak detection channel can flow back into the material receiving chamber.

[0041] The main beneficial effects of the above technical solution are as follows:

[0042] 1. An inclined leak detection channel is set according to the sealing structure, forming an indicator structure that can more timely and conveniently judge whether the sealing structure is excessively worn. In actual production, this indicator structure can be used to carry out maintenance in a timely and quick manner, and better mitigate the adverse effects caused by excessive wear of the sealing structure.

[0043] 2. The end faces of the stationary ring and the rotating ring are tightly fitted together under the action of spring force and medium pressure, forming an extremely narrow sealing interface, thus constituting a mechanical seal structure with a more stable sealing effect.

[0044] 3. By setting up a sleeve wall and a bearing structure that matches the sleeve wall, the stability of the active screw installation and operation is further improved, thereby enabling the three-screw pump to transport materials more stably and smoothly.

[0045] 4. Furthermore, in conjunction with the sleeve wall and bearing design, an outflow channel is provided on the sleeve wall, and the outflow channel is connected to the leak detection channel through the annular notch on the outer periphery of the sleeve wall. While forming the indicator structure as described above, the installation difficulty of the shaft seal sleeve is fully considered. It is not necessary to perform the difficult hole-to-hole precise alignment of the outflow channel and the leak detection channel when the observation line is obstructed. Instead, when the shaft seal sleeve is inserted into the sealing installation groove, the hole can be aligned with the large area notch, which greatly reduces the actual assembly difficulty of the three-screw pump.

[0046] 5. Several outflow channels are set based on the annular notch, which increases the detection area and enables materials to flow more quickly into the leak detection channel through the annular notch, regardless of where the leakage occurs in the sealing structure. This further improves the timeliness of detecting excessive wear of the sealing structure.

[0047] 6. A sealing ring is provided on both sides of the annular notch. On the one hand, it can improve the stability of the shaft seal sleeve in the sealing installation groove. On the other hand, it is equivalent to forming a limit on both sides of the outlet of the outflow channel, so that the material in the outflow channel can flow out more concentratedly into the leak detection channel to indicate the wear of the sealing structure in a timely manner, without overflowing to other unnecessary places.

[0048] 7. The storage tank, three-screw pump, feed pipe and return pipe together form a transmission system. While realizing the material conveying, the material flowing out of the leak detection channel can be returned to the storage tank for reuse, avoiding waste and pollution. Moreover, the other end of the return pipe is placed above the material receiving cavity, so that the return can be realized without affecting the judgment of whether there is excessive wear on the sealing structure.

[0049] Further or more detailed beneficial effects will be described in conjunction with specific embodiments in the detailed implementation. Attached Figure Description

[0050] The present invention will be further described below with reference to the accompanying drawings:

[0051] Figure 1 This is a cross-sectional view of a three-screw pump from a frontal perspective.

[0052] Figure 2 This is a cross-sectional view of a three-screw pump from a side view perspective.

[0053] Figure 3 A schematic diagram showing the setup of the sealing structure and the wear indicator structure.

[0054] Figure 4 This is a schematic diagram of a shaft seal sleeve with sleeve walls.

[0055] Figure 5 This is a schematic diagram of the overall structure of the transmission system. Detailed Implementation

[0056] The present invention will be illustrated with specific examples below: Example 1:

[0057] Three-screw pump, as attached Figure 1As shown, it is mainly used for transporting liquid materials. It mainly includes a pump casing 1, with a sealing mounting groove 1.4 facing upward on the upper end surface of the pump casing 1; and a material flow channel 1.1 is formed in a hollow cavity inside the pump casing 1. The lower end of the material flow channel 1.1 has an inlet 1.2 for material to flow in, and the upper end has an outlet 1.3 for material to flow out; the inlet 1.2, the material flow channel 1.1 and the outlet 1.3 together form a channel for directional conveying of materials.

[0058] Among them, as attached Figure 1 As shown, the bottom wall of the sealing installation groove 1.4 is provided with an insertion channel 1.5. The upper end of the insertion channel 1.5 is connected to the internal space of the sealing installation groove 1.4, and the lower end is connected to the logistics channel 1.1.

[0059] Meanwhile, the logistics channel 1.1 is also equipped with a screw assembly that transports materials from the inlet 1.2 to the outlet 1.3. The screw assembly includes: a drive screw 2 rotatably mounted on the pump housing 1 and capable of rotation; and a driven screw 3 rotatably mounted on the pump housing 1 and capable of rotation.

[0060] As attached Figure 1 and attached Figure 2 As shown, when the logistics channel 1.1 extends vertically and the outlet 1.3 is located above the inlet 1.2, both the driving screw 2 and the driven screw 3 are vertical shafts housed within the logistics channel 1.1. Two driven screws 3 are provided, positioned on either side of the driving screw 2 and connected to it via a helical drive. Specifically, the driving screw 2 has a first external thread extending axially on its outer periphery, and each driven screw 3 has a second external thread extending axially on its outer periphery; the first and second external threads are engaged. When the driving screw 2 rotates, it synchronously drives the two driven screws 3 to rotate. Liquid transport is achieved through the change in the volume of the sealed cavity formed by the meshing drive between the screws, thereby driving the material at the inlet 1.2 through the logistics channel 1.1 and out of the outlet 1.3.

[0061] As attached Figure 1 As shown, the upper end of the active screw 2 is connected to a shaft via a detachable connection, a non-detachable connection, or an integrally formed connection. This shaft forms a transmission shaft portion 2.1 extending upward from the upper end of the active screw 2.

[0062] The upper end of the drive shaft 2.1 passes through the insertion hole 1.5 to exit the material flow channel 1.1, and the upper end of the drive shaft 2.1 is placed in the sealing mounting groove 1.4 or passes through the sealing mounting groove 1.4 upwards.

[0063] As attached Figure 1As shown, a power unit 4 is also provided above the pump casing 1, which includes a rotary motor 4.1 for generating rotational power. The rotary motor 4.1 has a rotary output shaft for outputting rotational power. The power unit 4 also includes a motor frame 4.1 fixedly connected to the pump casing 1 to fix and support the rotary motor 4.1.

[0064] The upper end of the drive shaft 2.1 is connected to the rotating output shaft via, for example, a coupling, so that the power unit 4 can drive the drive screw 2 to rotate for the purpose of transporting materials. The power unit 4 covers the opening of the sealing mounting groove 1.4.

[0065] As attached Figure 3 As shown, the sealing mounting groove 1.4 is further provided with a sealing structure that fills the gap between the outer periphery of the drive shaft portion 2.1 and the side wall of the sealing mounting groove 1.4. This sealing structure divides the internal space of the sealing mounting groove 1.4 into sections located on one side of the sealing structure (as shown in the attached diagram). Figure 3 The first cavity 1.41 (above the central sealing structure), and the cavity located on the other side of the sealing structure (as shown in the attached diagram). Figure 3 The second cavity 1.42, located below the central sealing structure and connected to the insertion channel 1.5.

[0066] In this embodiment, as shown in the appendix Figure 3 As shown, the sealing structure includes: shaft seal sleeve 5, first sealing ring 6, stationary ring 7, and push assembly.

[0067] Specifically, the shaft seal sleeve 5 is an annular piece that fits onto the drive shaft portion 2.1 and is fixedly embedded in the sealing mounting groove 1.4; and, as shown in the attached... Figure 3 and attached Figure 4 As shown, the shaft seal 5 has an annular groove 5.1 arranged around the drive shaft portion 2.1 on one side facing the insertion channel 1.5. The annular groove 5.1 is an annular groove with openings on both the side facing the insertion channel 1.5 and the side facing the drive shaft portion 2.1.

[0068] The first sealing ring 6 is an annular piece made of elastic material such as silicone or rubber. It is fitted onto the shaft seal sleeve 5 and fills the gap between the outer periphery of the shaft seal sleeve 5 and the side wall of the sealing mounting groove 1.4, thereby forming the first part of the sealing structure between the outer periphery of the shaft seal sleeve 5 and the side wall of the sealing mounting groove 1.4.

[0069] As attached Figure 3 and attached Figure 4 As shown, to match the shape and structure of the first sealing ring 6, the outer surface of the shaft seal sleeve 5 can also have a first sealing mounting groove 5.2 formed. The first sealing mounting groove 5.2 is an annular groove with an outward opening and arranged around the drive shaft portion 2.1. The first sealing ring 6 is fitted into the first sealing mounting groove 5.2 to achieve stable positioning.

[0070] The stationary ring 7 is also an elastic ring made of elastic materials such as silicone or rubber. It is fitted onto the drive shaft 2.1 and has a portion that is positioned and accommodated in the annular groove 5.1. For example, the stationary ring 7 is adapted to be embedded in the annular groove 5.1.

[0071] The pushing assembly is an assembly that is placed between the bottom wall of the sealing mounting groove 1.4 and the stationary ring 7 and is capable of forming an elastic force. It is configured to apply an upward pushing force to the stationary ring 7 to drive the stationary ring 7 to deform and fill the gap between the shaft seal 5 and the drive shaft portion 2.1.

[0072] Furthermore, the pushing assembly may include a moving ring 8, a mounting base 15, and a pushing member 9.

[0073] Among them, as attached Figure 3 As shown, the moving ring 8 is an annular component made of a hard material such as metal, which is placed between the bottom wall of the sealing mounting groove 1.4 and the stationary ring 7, and is fitted onto the drive shaft portion 2.1. The moving ring 8 and the stationary ring 7 are aligned axially in the drive shaft portion 2.1.

[0074] Mounting base 15 is placed between the bottom wall of the sealing mounting groove 1.4 and the stationary ring 7, and is connected to the drive shaft 2.1 by means of, for example, a snap-fit ​​structure or screws, so that the mounting base 15 can rotate synchronously with the drive shaft 2.1. Mounting base 15 may also be a ring-shaped part made of a hard material such as metal and fitted onto the drive shaft 2.1.

[0075] Meanwhile, the pusher 9 is an elastic component, such as a spring. The pusher 9 is compressed and placed between the mounting base 15 and the moving ring 8 to apply a thrust to the stationary ring 7, causing the stationary ring 7 to deform and fill the gap between the shaft seal 5 and the drive shaft portion 2.1, thereby forming a second part with a sealing structure.

[0076] The first and second parts of the aforementioned sealing structure together constitute a complete sealing structure.

[0077] As attached Figure 3 As shown, the pump casing 1 is also provided with an inclined leak detection channel 1.6. The upper opening of the leak detection channel 1.6 is connected to the first cavity 1.41, and the lower opening is open so that when the material flows to the upper opening of the leak detection channel 1.6, it can flow into the leak detection channel 1.6 by its own weight and flow out from the lower opening.

[0078] As attached Figure 3 and attached Figure 4As shown, the side of the shaft seal sleeve 5 facing away from the insertion hole 1.5 may also have a protruding sleeve wall 5.3 extending around the drive shaft portion 2.1. This sleeve wall 5.3 is an annular member surrounding the drive shaft portion 2.1, and a bearing 10 may be fitted onto the drive shaft portion 2.1, positioned between the sleeve wall 5.3 and the drive shaft portion 2.1, to support the rotation of the drive shaft portion 2.1. The outer ring of the bearing 10 is snapped into the sleeve wall 5.3, and the inner ring is snapped into the drive shaft portion 2.1 to support the rotating drive shaft portion 2.1.

[0079] In the axial direction of the drive shaft portion 2.1, the sleeve wall 5.3 has a portion located between the bearing 10 and the stationary ring 7. This portion is provided with an outflow channel 5.31, one end of which is connected to the internal space of the sleeve wall 5.3, and the other end is connected to the upper opening of the leak detection channel 1.6, so that the material flowing into the internal space of the sleeve wall 5.3 can flow out from the outflow channel 5.31 into the leak detection channel 1.6.

[0080] As attached Figure 3 and attached Figure 4 As shown, the outer periphery of the sleeve wall 5.3 may also be provided with a discharge notch 5.22, which is an annular notch with an outward opening and arranged around the drive shaft portion 2.1. In the axial direction of the drive shaft portion 2.1, the discharge notch 5.22 is located on the side of the first sealing ring 6 facing away from the insertion channel 1.5; and the upper opening of the leak detection channel 1.6 is aligned with and connected to any part of the discharge notch 5.22, so that the other end of the outflow channel 5.31 is connected to the upper opening of the leak detection channel 1.6 through the discharge notch 5.22.

[0081] At this time, a number of outflow channels 5.31 can be provided on the sleeve wall 5.3. The number of outflow channels 5.31 are arranged at intervals around the drive shaft part 2.1. For each outflow channel 5.31, one end is connected to the internal space of the sleeve wall 5.3, and the other end is connected to the upper opening of the leak detection channel 1.6 through the discharge notch 5.22.

[0082] As attached Figure 3 and attached Figure 4 As shown, a second sealing mounting groove 5.4 is also formed on the outer surface of the shaft seal sleeve 5. The second sealing mounting groove 5.4 is an annular groove with an outward opening and arranged around the transmission shaft portion 2.1. In the axial direction of the transmission shaft portion 2.1, the second sealing mounting groove 5.4 is located on the side of the discharge notch 5.22 facing away from the insertion channel 1.5.

[0083] Furthermore, a second sealing ring 11, which is an annular piece made of elastic material such as silicone or rubber, is also fitted onto the shaft seal sleeve 5. The second sealing ring 11 is positioned and embedded in the second sealing mounting groove 5.4 and fills the gap between the outer periphery of the shaft seal sleeve 5 and the side wall of the sealing mounting groove 1.4, so as to form a further sealing structure between the outer periphery of the shaft seal sleeve 5 and the side wall of the sealing mounting groove 1.4.

[0084] When the three-screw pump is working normally:

[0085] Material is input from the feed inlet 1.2. The power unit 4 is energized to drive the active screw 2 to rotate, which in turn drives the two driven screws 3 to rotate synchronously. This causes the material at the feed inlet 1.2 to flow directionally through the material flow channel 1.1 to the discharge outlet 1.3, and then be output from the discharge outlet 1.3.

[0086] During this process, due to the structural requirements of the insert assembly, a gap will exist between the drive shaft 2.1 and the inner wall of the insert channel 1.5. Some of the material flowing in the material channel 1.1 will enter the second cavity 1.42 of the sealing mounting groove 1.4 through this gap under the action of conveying pressure. Due to the sealing structure, this part of the material will not continue to flow out of the sealing mounting groove 1.4 and cause leakage or affect the power unit 4.

[0087] When the sealing structure is damaged:

[0088] For example, when the sealing structure at the stationary ring 7 is damaged, the material in the second cavity 1.42 will flow into the internal space of the sleeve wall 5.3 in the first cavity 1.41 through the damaged part, and then flow through the outflow channel 5.31 and the discharge notch 5.22 to the upper opening of the leak detection channel 1.6, and then flow out through the leak detection channel 1.6, giving an indication that the sealing structure has been damaged in a timely manner.

[0089] Alternatively, for example, when the first sealing ring 6 is damaged (the statically fixed first sealing ring 6 is often not prone to damage or failure), the material flows into the first cavity 1.41 through the gap between the shaft seal sleeve 5 and the side wall of the sealing mounting groove 1.4, and then this part will flow to the upper opening of the leak detection channel 1.6 and flow out through the leak detection channel 1.6, giving an indication that the sealing structure has been damaged in a timely manner. Example 2:

[0090] The transmission system includes a three-screw pump as described in any of the embodiments in Example 1.

[0091] As attached Figure 5 As shown, the transmission system also includes a storage box 12, which has a material-containing cavity 12.1 for containing materials.

[0092] Furthermore, the storage tank 12 is connected to the three-screw pump by a feed pipe 13 and a return pipe 14.

[0093] One end of the conveying pipe 13 is connected to the material receiving chamber 12.1, and the other end is connected to the feed inlet 1.2, so that the material in the material receiving chamber 12.1 can be guided to the feed inlet 1.2.

[0094] One end of the return pipe 14 is connected to the lower opening of the leak detection channel 16, and the other end is positioned above the material receiving chamber 12.1 so that the material flowing into the leak detection channel 16 can flow back into the material receiving chamber 12.1.

[0095] Thus, during normal operation of the three-screw pump:

[0096] The material in the material receiving chamber 12.1 enters the feed inlet 1.2 through the conveying pipe 13, flows through the material flow channel 1.1, and is finally discharged directionally from the discharge outlet 1.3.

[0097] When the sealing structure of the active screw 2 is damaged, some material enters the leak detection channel 1.6 and flows into the return pipe 14 from the leak detection channel 1.6. Then, it flows from the lower end of the return pipe 14 into the material receiving chamber 12.1 for transportation and reuse, thus avoiding material waste.

[0098] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model. Furthermore, the terms "vertical," "horizontal," "front," and "rear," etc., mentioned in the embodiments of the present utility model, indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present utility model. It should be further noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" in the description should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present utility model according to the specific circumstances.

[0099] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A three-screw pump, including a pump housing (1) having a sealing mounting groove (1.4) formed on its surface and a material flow channel (1.1) having an inlet (1.2) at one end and an outlet (1.3) at the other end. The bottom wall of the sealing installation groove (1.4) is provided with an insertion channel (1.5) that communicates with the logistics channel (1.1). The logistics channel (1.1) is equipped with a screw assembly that transports materials from the feed inlet (1.2) to the discharge outlet (1.3), comprising: A rotatable driving screw (2), and two driven screws (3) that rotate with the driving screw (2); One end of the active screw (2) extends outward to form a drive shaft (2.1), which passes through the insertion hole (1.5) and is connected to a power device (4) that provides rotational force to the active screw (2). The feature is that the sealing mounting groove (1.4) is further provided with a sealing structure that fills the gap between the outer periphery of the transmission shaft part (2.1) and the side wall of the sealing mounting groove (1.4); The sealing structure divides the internal space of the sealing mounting groove (1.4) into: a first cavity (1.41) and a second cavity (1.42) communicating with the insertion channel (1.5). The pump casing (1) is also provided with a leak detection channel (1.6) that extends at an incline. The upper opening of the leak detection channel (1.6) is connected to the first cavity (1.41), and the lower opening is open.

2. The three-screw pump according to claim 1, characterized in that: The sealing structure includes: The shaft seal sleeve (5), which is fixed in the sealing mounting groove (1.4) and sleeved on the drive shaft part (2.1), has an annular groove (5.1) arranged around the drive shaft part (2.1) on one side facing the insertion hole (1.5). A first sealing ring (6) is fitted onto the shaft seal sleeve (5) and fills the gap between the outer periphery of the shaft seal sleeve (5) and the side wall of the sealing mounting groove (1.4). A flexible stationary ring (7) is fitted onto the drive shaft portion (2.1) and has a portion that is positioned and accommodated in the annular groove (5.1); The push assembly placed between the bottom wall of the sealing mounting groove (1.4) and the stationary ring (7) is configured to apply a thrust to the stationary ring (7) to cause the stationary ring (7) to deformably fill the gap between the shaft sleeve (5) and the drive shaft portion (2.1).

3. The three-screw pump according to claim 2, characterized in that: The pushing assembly includes: A rotating ring (8) is placed between the bottom wall of the sealing mounting groove (1.4) and the stationary ring (7), and is fitted on the transmission shaft (2.1). In the axial direction of the transmission shaft (2.1), the rotating ring (8) is aligned with the stationary ring (7). A mounting base (15) is placed between the bottom wall of the sealing mounting groove (1.4) and the stationary ring (7), and rotates synchronously with the transmission shaft (2.1). An elastic pusher (9) is positioned in a compressed manner between the mounting base (15) and the moving ring (8) to apply a thrust to the stationary ring (7) to cause the stationary ring (7) to deform.

4. The three-screw pump according to claim 2, characterized in that: The outer surface of the shaft seal sleeve (5) is formed with a first sealing mounting groove (5.2), which is an annular groove with an opening facing outward and arranged around the drive shaft portion (2.1); The first sealing ring (6) is fitted into the first sealing mounting groove (5.2).

5. The three-screw pump according to any one of claims 2 to 4, characterized in that: The shaft seal (5) has a sleeve wall (5.3) that protrudes from one side of the insertion channel (1.5) and extends around the drive shaft portion (2.1). The drive shaft (2.1) is fitted with a bearing (10) which is placed between the sleeve wall (5.3) and the drive shaft (2.1) and supports the rotation of the drive shaft (2.1). In the axial direction of the transmission shaft (2.1), the sleeve wall (5.3) has a portion placed between the bearing (10) and the stationary ring (7), which is provided with an outflow channel (5.31), one end of which is connected to the internal space of the sleeve wall (5.3), and the other end is connected to the upper opening of the leak detection channel (1.6).

6. The three-screw pump according to claim 5, characterized in that: The outer periphery of the sleeve wall (5.3) is provided with a discharge notch (5.22), which is an annular notch with the opening facing outward and arranged around the drive shaft part (2.1); In the axial direction of the drive shaft (2.1), the discharge notch (5.22) is located on the side of the first sealing ring (6) facing away from the insertion channel (1.5); Furthermore, the other end of the outflow channel (5.31) is connected to the upper opening of the leak detection channel (1.6) through the discharge notch (5.22).

7. The three-screw pump according to claim 6, characterized in that: The sleeve wall (5.3) is provided with a plurality of outflow channels (5.31), and the plurality of outflow channels (5.31) are arranged at intervals around the drive shaft (2.1).

8. The three-screw pump according to claim 6, characterized in that: The outer surface of the shaft seal sleeve (5) is formed with a second sealing mounting groove (5.4), which is an annular groove with an outward opening and arranged around the drive shaft portion (2.1); In the axial direction of the drive shaft (2.1), the second sealing mounting groove (5.4) is located on the side of the discharge notch (5.22) facing away from the insertion channel (1.5); Furthermore, the second sealing mounting groove (5.4) is fitted with a second sealing ring (11) that fills the gap between the outer periphery of the shaft seal sleeve (5) and the side wall of the sealing mounting groove (1.4).

9. A transmission system, characterized in that: It includes the three-screw pump as described in any one of claims 1 to 8.

10. The transmission system according to claim 9, characterized in that: The transmission system also includes: Storage box (12), which has a material-containing cavity (12.1) for holding transport materials. The material conveying pipe (13) has one end connected to the material receiving chamber (12.1) and the other end connected to the feed inlet (1.2) so as to guide the material in the material receiving chamber (12.1) to the feed inlet (1.2); The return pipe (14) has one end connected to the lower opening of the leak detection channel (1.6) and the other end positioned above the material container (12.1) so that the material flowing into the leak detection channel (1.6) can be returned to the material container (12.1).

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