Multi-stage internal screw pump driven by hole type servo motor

Abstract

The utility model discloses a multi-stage internal spiral pump driven by a hole type servo motor, which belongs to the technical field of spiral pumps, a stator is matched with a rotor to realize that the rotor drives a rotating sleeve to rotate in a mounting cavity, and when the rotating sleeve and the rotor synchronously rotate, a spiral cavity is formed between a spiral blade in a liquid conveying hole of an internal spiral sleeve and a core shaft; liquid flows from the liquid inlet hole to the circulation hole through the spiral cavity, and then flows to the liquid outlet hole from the circulation hole; the stator and the rotor of the motor, the rotating sleeve related to the screw pump, the inner spiral sleeve and the mandrel are integrated together to form the inner spiral pump of a special structure, the structure of the spiral pump is more compact, the size of the spiral pump is small, the spiral blades are arranged on the inner side wall of the liquid conveying hole of the inner spiral sleeve, and the rotor drives the rotating sleeve and the inner spiral sleeve to rotate. Compared with a conventional pump shaft, the inner spiral sleeve can bear larger twisting force, high-speed liquid conveying of the inner spiral pump is facilitated, and a high-speed high-pressure power source composed of a stator and a rotor can be adapted.

Description

Technical Field

[0001] The utility model relates to the technical field of screw pumps, in particular to a multi-stage internal screw pump driven by a hole-type servo motor. Background Art

[0002] A conventional screw pump is called an Archimedes screw pump, which is a pump that uses the rotation of a screw blade to make a liquid rise axially in a spiral shape. Specifically, the screw pump is composed of a screw blade, a pump shaft, and a housing. The screw blade is arranged outside the pump shaft, and the pump shaft drives the screw blade to rotate inside the housing, so that the liquid is conveyed along the space between the screw blade and the housing. However, the end of the pump shaft of the existing screw pump is connected to the motor, making the structure of the screw pump relatively loose, and the pump shaft driving the screw blade to rotate causes the pump shaft to bear a large torsional force, resulting in that the existing screw pump is only suitable for liquid transportation at a low speed, and it is difficult for the pump shaft to adapt to a high-speed and high-pressure power source. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides a multi-stage internal screw pump driven by a hole-type servo motor. The stator and rotor of the motor, the rotating sleeve, the internal spiral sleeve, and the core shaft related to the internal screw pump are integrated to form an internal screw pump with a special structure, making the structure of the internal screw pump more compact and smaller in volume. Compared with the conventional pump shaft, the internal spiral sleeve can withstand a greater torsional force, which helps the internal screw pump to achieve high-speed liquid transportation and helps to adapt to the high-speed and high-pressure power source composed of the stator and rotor.

[0004] The multi-stage internal screw pump driven by a hole-type servo motor according to an embodiment of the utility model includes:

[0005] A housing provided with an installation cavity, and liquid inlet holes and liquid outlet holes communicating with the installation cavity are respectively provided on the front and rear sides of the housing;

[0006] A bearing group arranged in the installation cavity;

[0007] A stator arranged in the installation cavity, and the stator is provided with an inner hole penetrating through the front and rear;

[0008] A rotor rotatably arranged in the inner hole;

[0009] A rotating sleeve, the outer wall of which connects the rotor and the bearing group, the rotor drives the rotating sleeve to rotate, and the rotating sleeve is provided with an assembly hole penetrating through the front and rear;

[0010] An internal spiral sleeve arranged in the assembly hole, the internal spiral sleeve rotates synchronously with the rotating sleeve, the internal spiral sleeve is provided with a liquid infusion hole penetrating through the front and rear, and the inner side wall of the liquid infusion hole is provided with spiral blades spirally arranged around the axis;

[0011] The mandrel is connected to the housing. The mandrel passes through the infusion hole. A spiral cavity is formed between the outer side wall of the mandrel and the spiral blade. A circulation hole is provided at the rear side of the mandrel, and the circulation hole communicates the liquid outlet hole with the spiral cavity.

[0012] The multi-stage internal spiral pump driven by a hole-type servo motor according to an embodiment of the present invention has at least the following beneficial effects: The stator and the rotor are arranged in the installation cavity of the housing. The rotating sleeve is installed in the installation cavity through a bearing group. The stator and the rotor cooperate to enable the rotor to drive the rotating sleeve to rotate in the installation cavity. When the rotating sleeve rotates synchronously with the rotor, a spiral cavity is formed between the spiral blade in the infusion hole of the internal spiral sleeve and the mandrel, so that the liquid flows from the liquid inlet hole through the spiral cavity to the circulation hole, and then the liquid flows from the circulation hole to the liquid outlet hole; The stator and the rotor of the motor, the rotating sleeve, the internal spiral sleeve and the mandrel related to the internal spiral pump are integrated together to form an internal spiral pump with a special structure. Since the rotor drives the rotating sleeve and the internal spiral sleeve to rotate on the outside, the structure of the internal spiral pump is more compact and the volume is smaller. Since the spiral blade is arranged on the inner side wall of the infusion hole of the internal spiral sleeve, and the rotor drives the rotating sleeve and the internal spiral sleeve to rotate, compared with a conventional pump shaft, the internal spiral sleeve can withstand a greater torsional force, which helps the internal spiral pump to achieve high-speed liquid delivery and helps to adapt to the high-speed and high-pressure power source composed of the stator and the rotor.

[0013] According to some embodiments of the present invention, there are a plurality of the internal spiral sleeves, and the plurality of internal spiral sleeves are arranged in sequence in the front-rear direction. A plurality of the spiral cavities are formed between the outer side wall of the mandrel and all the spiral blades, and the liquid flow cross-sectional areas of the plurality of spiral cavities gradually decrease from front to back.

[0014] According to some embodiments of the present invention, a plurality of steps arranged in sequence from front to back are provided on the outer side wall of the mandrel, and the plurality of steps are arranged in one-to-one correspondence with the plurality of internal spiral sleeves, and the outer diameters of the plurality of steps gradually increase from front to back.

[0015] According to some embodiments of the present invention, the lengths of the plurality of spiral blades extending towards the axis gradually decrease from front to back.

[0016] According to some embodiments of the present invention, the pitches of the plurality of spiral blades gradually decrease from front to back.

[0017] According to some embodiments of the present invention, a first keyway arranged in the front-rear direction is provided on the inner side wall of the assembly hole, and a second keyway penetrating in the front-rear direction is provided on the outer side wall of each internal spiral sleeve. The multi-stage internal spiral pump further includes:

[0018] A positioning key, one side of the positioning key is engaged with the first keyway, and the other side of the positioning key is engaged with all the second keyways.

[0019] According to some embodiments of the present utility model, the housing includes:

[0020] A mounting seat, provided with the mounting cavity penetrating through the front and rear, and the inner side wall of the mounting cavity is provided with a protrusion;

[0021] A front flange ring, connecting the front end face of the mounting seat, and the rear side of the front flange ring and the front side of the protrusion respectively abut against the front and rear sides of the bearing group;

[0022] A rear flange ring, connecting the rear end face of the mounting seat, and the rear side of the protrusion and the front side of the rear flange ring abut against the front and rear sides of the stator.

[0023] According to some embodiments of the present utility model, the housing further includes:

[0024] A front end cover, provided with the liquid inlet hole penetrating through the front and rear, and the front end cover is connected to the front flange ring;

[0025] A front sealing ring, sealing the front end of the front end cover and the rotating sleeve.

[0026] According to some embodiments of the present utility model, the housing further includes:

[0027] A rear end cover, provided with the liquid outlet hole, the rear end cover is connected to the rear flange ring, and the front side of the rear end cover is connected to the rear end of the core shaft;

[0028] A rear sealing ring, sealing the rear end of the rear end cover and the rotating sleeve or sealing the rear end of the core shaft and the rotating sleeve.

[0029] According to some embodiments of the present utility model, the multi-stage internal screw pump further includes:

[0030] An annular encoder moving ring, installed on the outer side wall of the rotating sleeve;

[0031] An encoder reading head, arranged on the inner wall of the mounting cavity, and the encoder reading head is located outside the annular encoder moving ring. Description of the Drawings

[0032] Figure 1 is a schematic structural diagram of a multi-stage internal screw pump driven by a hole-type servo motor according to an embodiment of the present utility model;

[0033] Figure 2 is a schematic cross-sectional view of a multi-stage internal screw pump driven by a hole-type servo motor according to an embodiment of the present utility model;

[0034] Figure 3 is an exploded schematic diagram of a multi-stage internal screw pump driven by a hole-type servo motor according to an embodiment of the present utility model.

[0035] Reference numerals: housing 100, mounting base 101, front flange ring 102, rear flange ring 103, front end cover 104, front sealing ring 105, rear end cover 106, rear sealing ring 107, mounting cavity 110, protrusion 111, liquid inlet hole 120, liquid outlet hole 130, bearing set 200, rear support bearing 210, stator 300, inner hole 310, rotor 400, rotating sleeve 500, assembly hole 510, first keyway 511, inner spiral sleeve 600, liquid delivery hole 610, spiral blade 620, spiral cavity 621, second keyway 630, snap ring 640, spacer sleeve 650, core shaft 700, circulation hole 710, step 720, positioning key 800, moving ring of annular encoder 900, encoder reading head 910. Detailed implementation manners

[0036] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0037] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as front, rear, upper, lower, axial direction, circumferential direction, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0038] In the description of the present utility model, the meaning of "a plurality" is more than two. Understandings such as greater than, less than, exceeding, etc. do not include the present number, and understandings such as above, below, within, etc. include the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0039] In the description of the present utility model, it should be noted that words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solution.

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the drawings. Obviously, the following described embodiments are some embodiments of the present utility model, not all embodiments.

[0041] Referring to Figures 1 to 3 As shown, the present utility model provides a multi-stage internal spiral pump driven by a hole-type servo motor.

[0042] The multi-stage internal spiral pump driven by a hole-type servo motor includes a housing 100, a bearing group 200, a stator 300, a rotor 400, a rotating sleeve 500, a plurality of internal spiral sleeves 600, a core shaft 700, a positioning key 800, a moving ring 900 of a ring encoder, and an encoder reading head 910.

[0043] Refer to Figures 1 to 3 As shown, the housing 100 includes a mounting seat 101, a front flange ring 102, a rear flange ring 103, a front end cover 104, a plurality of front sealing rings 105, a rear end cover 106, and a plurality of rear sealing rings 107.

[0044] The mounting seat 101 is provided with a mounting cavity 110 that penetrates in the front-rear direction. The mounting cavity 110 is in the shape of a circular hole that penetrates in the front-rear direction. A protrusion 111 that protrudes toward the axis is provided on the inner side wall of the mounting cavity 110. The protrusion 111 surrounds the circumference of the mounting cavity 110 in a circle.

[0045] The front flange ring 102 is in a circular ring shape. A front assembly ring that protrudes backward is provided on the rear side of the front flange ring 102. The shape of the front assembly ring matches the shape of the front end of the mounting cavity 110. The front assembly ring is inserted into the front end of the mounting cavity 110. The front flange ring 102 is connected to the front end face of the mounting seat 101 by screws.

[0046] The rear flange ring 103 is in a circular ring shape. A rear assembly ring that protrudes forward is provided on the front side of the rear flange ring 103. The shape of the rear assembly ring matches the shape of the rear end of the mounting cavity 110. The rear assembly ring is inserted into the rear end of the mounting cavity 110. The rear flange ring 103 is connected to the rear end face of the mounting cavity 110 by screws.

[0047] A first annular mounting groove is provided on the front end face of the rear flange ring 103. The first annular mounting groove surrounds the circumference of the rear flange ring 103 in a circle. The rear support bearing 210 is arranged in the first annular mounting groove. The outer ring of the rear support bearing 210 abuts against the inner wall of the first annular mounting groove. A second annular mounting groove is provided on the rear end face of the rear flange ring 103. The second annular mounting groove surrounds the circumference of the rear flange ring 103 in a circle. The moving ring 900 of the ring encoder is arranged in the second annular mounting groove.

[0048] The front end cover 104 is provided with a liquid inlet hole 120 that penetrates in the front-rear direction. A tapered hole that is large at the front and small at the rear is provided at the rear end of the liquid inlet hole 120. The tapered hole is conducive to accelerating the flow of liquid. The front end cover 104 is connected to the front end face of the front flange ring 102 by screws. A mounting seat that protrudes backward is provided on the rear side of the front end cover 104. A plurality of stepped rings are provided on the mounting seat. The outer diameters of the plurality of stepped rings gradually decrease from front to back, making the mounting seat form a stepped structure. At least one side wall of the stepped ring is provided with a first front sealing groove, and at least one end face of the stepped ring is provided with a second front sealing groove. The two front sealing rings 105 are respectively arranged in the first front sealing groove and the second front sealing groove.

[0049] A liquid outlet hole 130 extending forward is provided on the rear side of the rear end cover 106. The rear end face of the rear end cover 106 is connected to the rear end face of the rear flange ring 103 by screws. The front end of the rear end cover 106 is integrally formed with the core shaft 700, that is, the rear end of the core shaft 700 is fixedly connected to the front end face of the rear end cover 106. The core shaft 700 extends into the installation cavity 110 of the installation seat 101. A plurality of radially penetrating circulation holes 710 are provided on the outer side wall of the rear end of the core shaft 700. The front end of the liquid outlet hole 130 communicates with all the circulation holes 710.

[0050] A first rear sealing groove is provided on the front end face of the rear end cover 106. Two second rear sealing grooves are provided on the outer side wall of the rear end of the core shaft 700. Three rear sealing rings 107 are respectively arranged in the first rear sealing groove and the two second rear sealing grooves.

[0051] The bearing group 200 is arranged in the installation cavity 110. The bearing group 200 is arranged between the front flange ring 102 and the protrusion 111. The outer ring of the bearing group 200 abuts against the inner side wall of the installation cavity 110. The front end face of the outer ring of the bearing group 200 abuts against the rear end face of the front assembly ring of the front flange ring 102. The rear end face of the outer ring of the bearing group 200 abuts against the front end face of the protrusion 111.

[0052] The front flange ring 102 and the protrusion 111 are provided to limit the position of the bearing group 200, so that the bearing group 200 is assembled into the installation cavity 110 more compactly.

[0053] The stator 300 is arranged in the installation cavity 110. The stator 300 is arranged between the protrusion 111 and the rear flange ring 103. The outer side wall of the stator 300 abuts against the inner side wall of the installation cavity 110. The front end face of the stator 300 abuts against the rear end face of the protrusion 111. The rear end face of the stator 300 abuts against the front end face of the rear flange ring 103. The stator 300 is provided with an inner hole 310 penetrating in the front-rear direction. The rotor 400 is arranged in the inner hole 310.

[0054] The rear flange ring 103 and the protrusion 111 are provided to limit the position of the stator 300, so that the stator 300 is assembled into the installation cavity 110 more compactly.

[0055] The rotating sleeve 500 is arranged in the installation cavity 110. The inner ring of the bearing group 200 is sleeved on the outer wall of the rotating sleeve 500. The rotor 400 is sleeved on the outside of the rotating sleeve 500. The inner ring of the rear support bearing 210 is sleeved on the outside of the rotating sleeve 500.

[0056] A gap is left between the outer side wall at the front end of the rotating sleeve 500 and the inner side wall of the front flange ring 102 to facilitate the rotation of the rotating sleeve 500 relative to the front flange ring 102.

[0057] The rotating sleeve 500 is provided with an assembly hole 510 penetrating in the front-rear direction. The front end of the rotating sleeve 500 is provided with a stepped groove, and the stepped groove is provided with a plurality of stepped holes penetrating in the front-rear direction. The shape of the stepped groove matches the shape of the assembly seat of the front end cover 104. The assembly seat is inserted into the stepped groove, and there is a gap between the inner wall of the stepped groove and the outer wall of the assembly seat, so as to facilitate the rotation of the rotating sleeve 500 relative to the assembly seat of the front end cover 104. Two front sealing rings respectively seal the inner side wall and the end face of the stepped hole, and the two front sealing rings seal the gap between the stepped groove and the assembly seat, preventing liquid from entering the area where the stator 300 and the rotor 400 are located through the gap at the front end of the rotating sleeve 500.

[0058] There is a gap between the outer side wall of the rotating sleeve 500 and the inner side wall of the rear flange ring 103, a gap between the rear end face of the rotating sleeve 500 and the rear end cover 106, and a gap between the inner side wall of the assembly hole 510 of the rotating sleeve 500 and the outer side wall of the core shaft 700, so as to facilitate the rotation of the rotating sleeve 500 relative to the rear flange ring 103, the rear end cover 106 and the core shaft 700.

[0059] The rear sealing ring 107 located on the front end face of the rear end cover 106 abuts against the rear end face of the rotating sleeve 500 and seals the gap between the rear end face of the rotating sleeve 500 and the front end face of the rear end cover 106. The two rear sealing rings 107 located on the outer side wall of the rear end of the core shaft 700 abut against the inner side wall of the assembly hole 510 of the rotating sleeve 500 and seal the gap between the inner side wall of the assembly hole 510 of the rotating sleeve 500 and the outer side wall of the rear end of the core shaft 700, preventing liquid from entering the area where the stator 300 and the rotor 400 are located through the gap at the rear end of the rotating sleeve 500.

[0060] The inner ring of the bearing group 200 is sleeved on the outer side wall of the front side of the rotating sleeve 500. A first limiting ring is sleeved on the outer side wall of the rotating sleeve 500, and the front end face of the first limiting ring abuts against the rear end face of the inner ring of the bearing group 200. The stepped groove protrudes outwards to form a stepped surface on the outer side wall of the front end of the rotating sleeve 500, and the front end face of the inner ring of the bearing group 200 abuts against the stepped surface.

[0061] The rotor 400 is sleeved on the outer side wall of the rear side of the rotating sleeve 500. An annular step is provided on the outer side wall of the rotating sleeve 500, and the annular step abuts against the front end face of the rotor 400. A second limiting ring is sleeved on the outer side wall of the rotating sleeve 500, and the front end face of the second limiting ring abuts against the rear end face of the rotor 400.

[0062] The inner ring of the rear support bearing 210 is sleeved on the outer side wall of the rear end of the rotating sleeve 500. The front end and the rear end of the rotating sleeve 500 are respectively supported by the bearing group 200 and the rear support bearing 210. The inner ring of the bearing group 200, the rotating sleeve 500 and the rotor 400 can rotate in the installation cavity 110. The stator 300 and the rotor 400 cooperate to realize the rotation of the rotor 400 and drive the rotating sleeve 500 to rotate in the installation cavity 110.

[0063] The encoder reading head 910 is arranged at the rear end of the rotating sleeve 500. The encoder reading head 910 faces the inner side of the annular encoder moving ring 900. The rotating sleeve 500 drives the encoder reading head 910 to rotate, so that the encoder reading head 910 rotates relative to the annular encoder moving ring 900, enabling the encoder reading head 910 to read the accurate rotation angle of the rotating sleeve 500, and further accurately controlling the number of rotation turns of the inner spiral sleeve 600, which helps to accurately control the liquid delivery of the inner spiral pump.

[0064] A first keyway 511 extending in the front-rear direction is arranged on the inner side wall of the assembly hole 510. The side wall of the positioning key 800 facing away from the axis of the rotating sleeve 500 is inserted into the first keyway 511.

[0065] Three inner spiral sleeves 600 are arranged in the assembly hole 510 at intervals from front to back in sequence. A second keyway 630 penetrating in the front-rear direction is arranged on the outer side wall of each inner spiral sleeve 600. The side wall of the positioning key 800 facing the inner spiral sleeve 600 is inserted into the three second keyways 630, so that the rotating sleeve 500 can drive the three inner spiral sleeves 600 to rotate through the positioning key 800.

[0066] The positioning key 800 is used to synchronously rotate the inner spiral sleeve 600 and the rotating sleeve 500. Since the positioning key 800 is fitted in the first keyway 511 and the second keyway 630, it helps to reduce the positioning accuracy requirements for connecting the inner spiral sleeve 600 and the rotating sleeve 500, and it is more convenient to assemble the inner spiral sleeve 600 into the assembly hole 510 of the rotating sleeve 500.

[0067] Each inner spiral sleeve 600 is provided with an infusion hole 610 penetrating in the front-rear direction. A spiral blade 620 is arranged on the inner side wall of each infusion hole 610, and the spiral blade 620 extends spirally around the axis of the inner spiral sleeve 600.

[0068] A spacer sleeve 650 is arranged between every two adjacent inner spiral sleeves 600 in the front-rear direction. The outer diameter of the spacer sleeve 650 is the same as that of the inner spiral sleeve 600, and the inner diameter of the spacer sleeve 650 is the same as the aperture of the infusion hole 610 of the inner spiral sleeve 600. A third keyway is arranged on the outer side wall of each spacer sleeve 650, and the side wall of the positioning key 800 facing the inner spiral sleeve 600 is inserted into the third keyway.

[0069] A rear limiting block protruding inward is provided at the rear end of the assembly hole 510, and a limiting groove protruding outward is provided at the front end of the assembly hole 510. The snap ring 640 is arranged in the limiting groove. The rear end face of the innermost spiral sleeve 600 at the rearmost side abuts against the rear limiting block, and the front end face of the innermost spiral sleeve 600 at the foremost side abuts against the snap ring 640. Thus, the three innermost spiral sleeves 600 and the two spacer sleeves 650 are limited in the assembly hole 510, preventing the innermost spiral sleeve 600 from moving relative to the rotating sleeve 500 in the front-rear direction.

[0070] The mandrel 700 is inserted into the infusion holes 610 of the three innermost spiral sleeves 600 from the rear to the front. A spiral chamber 621 is formed between the spiral blades 620 of each innermost spiral sleeve 600 and the outer side wall of the mandrel 700. Three steps 720 are provided on the outer side wall of the mandrel 700, and an inclined angle transition is provided between every two adjacent steps 720 in the front-rear direction. The three steps 720 correspond to the positions of the three innermost spiral sleeves 600 one by one, and a gap is left between the outer side wall of each step 720 and the end of the corresponding spiral blade 620.

[0071] The outer diameters of the three steps 720 increase gradually from the front to the rear, the distances that the three spiral blades 620 extend towards the axis decrease gradually from the front to the rear, and the pitches of the three spiral blades 620 decrease gradually from the front to the rear. Thus, the flow cross-sectional areas of the three spiral chambers 621 decrease gradually from the front to the rear.

[0072] After the liquid enters from the liquid inlet hole 120, the liquid flows along the three spiral chambers 621. The flow cross-sectional areas of the three spiral chambers 621 decrease gradually from the front to the rear, which helps to accelerate the flow of the liquid and enables the liquid to increase in speed and pressure step by step.

[0073] There are the above three ways to achieve the gradual decrease of the flow cross-sectional areas of the multiple spiral chambers 621 from the front to the rear. One or more of the above three ways can be selected separately or simultaneously.

[0074] Among them, the outer diameters of the multiple steps 720 of the mandrel 700 increase gradually from the front to the rear. Since the mandrel 700 does not need to rotate while the multiple spiral blades 620 around the mandrel 700 rotate, it helps to reduce the power requirement for the rotor 400 to drive the innermost spiral sleeve 600 to rotate.

[0075] Among them, the distances that the multiple spiral blades 620 extend towards the axis decrease gradually from the front to the rear, reducing the weight of the spiral blades 620 at the rear side, which helps to balance the torsional forces of the multiple innermost spiral sleeves 600 at different positions and reduce noise.

[0076] Among them, the pitches of the multiple spiral blades 620 decrease gradually from the front to the rear, which helps the flow rate and pressure of the liquid to increase step by step.

[0077] Conventional screw pumps are called Archimedes screw pumps and have a very long application history. Before the emergence of motors, there were various power sources to drive screw pumps. Currently, since screw pumps need to use a pump shaft to connect to the motor, with spiral blades arranged outside the pump shaft, the pump shaft is relatively slender and has poor structural strength, and the pump shaft needs to bear a large torsional force, resulting in screw pumps being only suitable for material transportation at low speeds and unable to adapt to high-speed and high-pressure power sources.

[0078] The conventional spiral blades fixed on the slender pump shaft have insufficient rigidity and it is difficult to achieve high-speed rotation. However, the spiral blades 620 inside the inner spiral sleeve 600 of the present utility model are fixed on the inner wall, generally precision machined parts, which can achieve high-speed rotation and have relatively large self-rigidity. Therefore, the inner screw pump of this embodiment can be used as a high-pressure, high-speed and large-flow pump, and such a pump can be used for the water spray guns of fire fighting, the water cannons of coast guard ships, and the rapid liquid filling in hydraulic construction machinery, etc.

[0079] The stator 300 and the rotor 400 are arranged in the installation cavity 110 of the housing 100. The rotating sleeve 500 is installed in the installation cavity 110 through the bearing group 200. The stator 300 and the rotor 400 cooperate to enable the rotor 400 to drive the rotating sleeve 500 to rotate in the installation cavity 110. When the rotating sleeve 500 and the rotor 400 rotate synchronously, a spiral cavity 621 is formed between the spiral blades 620 in the liquid delivery holes 610 of the inner spiral sleeve 600 and the core shaft 700, so that the liquid flows from the liquid inlet hole 120 through the spiral cavity 621 to the circulation hole 710, and then the liquid flows from the circulation hole 710 to the liquid outlet hole 130; the stator 300 and the rotor 400 of the motor, the rotating sleeve 500 related to the inner screw pump, the inner spiral sleeve 600 and the core shaft 700 are integrated together to form an inner screw pump with a special structure. Since the rotor 400 drives the rotating sleeve 500 and the inner spiral sleeve 600 to rotate on the outside, the structure of the inner screw pump is more compact and has a smaller volume. Since the spiral blades 620 are arranged on the inner side wall of the liquid delivery holes 610 of the inner spiral sleeve 600, and the rotor 400 drives the rotating sleeve 500 and the inner spiral sleeve 600 to rotate, compared with the conventional pump shaft, the inner spiral sleeve 600 can bear a greater torsional force, which helps the inner screw pump to achieve high-speed liquid transportation and helps to adapt to the high-speed and high-pressure power source composed of the stator 300 and the rotor 400.

[0080] In some embodiments, there are various ways to connect the rotating sleeve 500 to the inner helical sleeve 600. For example, the assembly hole 510 of the rotating sleeve 500 is welded or bonded to the inner helical sleeve 60, or is connected to the inner side wall of the assembly hole 510 of the rotating sleeve 500 by screws from the inner side of the inner helical sleeve 600; or a rib extending in the front-rear direction is provided on the inner side wall of the assembly hole 510, and a groove penetrating in the front-rear direction is provided on the outer side wall of each inner helical sleeve 600, so that the inner helical sleeve 600 can be inserted into the assembly hole 510 in the front-rear direction, and the cooperation between the groove and the rib enables the rotating sleeve 500 to drive the inner helical sleeve 600 to rotate.

[0081] In some embodiments, one inner helical sleeve 600 is provided. When the flow cross-sectional area of the spiral cavity 621 between the spiral blade 620 inside the inner helical sleeve 600 and the core shaft 700 remains unchanged, the inner spiral pump can still achieve normal liquid transportation function. Of course, the pitch of the spiral blade 620 inside the inner helical sleeve 600 can be gradually decreased from front to back, and the distance that the spiral blade 620 extends towards the axis can be gradually decreased from front to back, so as to achieve pressurization by the way that the flow cross-sectional area of the spiral cavity 621 is gradually decreased from front to back.

[0082] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention within the knowledge of those of ordinary skill in the art.

Claims

1. A multi-stage internal screw pump driven by a hole-type servo motor, characterized in that, Comprising: A housing provided with an installation cavity, and liquid inlet holes and liquid outlet holes communicating with the installation cavity are respectively provided on the front and rear sides of the housing; A bearing group arranged in the installation cavity; A stator arranged in the installation cavity, and the stator is provided with an inner hole penetrating through the front and rear; A rotor rotatably arranged in the inner hole; A rotating sleeve, the outer wall of which connects the rotor and the bearing group, the rotor drives the rotating sleeve to rotate, and the rotating sleeve is provided with an assembly hole penetrating through the front and rear; An inner spiral sleeve arranged in the assembly hole, the inner spiral sleeve rotates synchronously with the rotating sleeve, the inner spiral sleeve is provided with a liquid infusion hole penetrating through the front and rear, and the inner side wall of the liquid infusion hole is provided with spiral blades spirally arranged around the axis; A core shaft connected to the housing, the core shaft penetrates through the liquid infusion hole, a spiral cavity is formed between the outer side wall of the core shaft and the spiral blades, a circulation hole is provided at the rear side of the core shaft, and the circulation hole communicates the liquid outlet hole with the spiral cavity.

2. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 1, wherein There are multiple inner spiral sleeves, and the multiple inner spiral sleeves are arranged in sequence in the front-rear direction. Multiple spiral cavities are formed between the outer side wall of the core shaft and all the spiral blades, and the liquid flow cross-sectional areas of the multiple spiral cavities gradually decrease from front to back.

3. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 2, characterized in that, The outer side wall of the core shaft is provided with multiple steps arranged in sequence from front to back, the multiple steps are arranged in one-to-one correspondence with the multiple inner spiral sleeves, and the outer diameters of the multiple steps gradually increase from front to back.

4. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 2, characterized in that, The lengths of the multiple spiral blades extending towards the axis gradually decrease from front to back.

5. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 2, characterized in that, The pitches of the multiple spiral blades gradually decrease from front to back.

6. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 2, characterized in that, The inner side wall of the assembly hole is provided with a first keyway arranged in the front-rear direction, and the outer side wall of each inner spiral sleeve is provided with a second keyway penetrating through in the front-rear direction. The multi-stage inner spiral pump further includes: A positioning key, one side of the first keyway cooperates with the positioning key, and the other side of all the second keyways cooperates with the positioning key.

7. The multi-stage internal spiral pump driven by a hole-type servo motor according to claim 1, wherein, The housing includes: A mounting seat provided with the installation cavity penetrating through the front and rear, and a protrusion is provided on the inner side wall of the installation cavity; A front flange ring connected to the front end face of the mounting seat, and the front and rear sides of the bearing group are respectively abutted against the rear side of the front flange ring and the front side of the protrusion; A rear flange ring connected to the rear end face of the mounting seat, and the front and rear sides of the stator are abutted against the rear side of the protrusion and the front side of the rear flange ring.

8. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 7, characterized in that, The housing further includes: A front end cover provided with the liquid inlet hole penetrating through the front and rear, and the front end cover is connected to the front flange ring; A front sealing ring for sealing the front end of the front end cover and the rotating sleeve.

9. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 7, characterized in that, The housing further includes: A rear end cover provided with the liquid outlet hole, the rear end cover is connected to the rear flange ring, and the front side of the rear end cover is connected to the rear end of the core shaft; A rear sealing ring for sealing the rear end of the rear end cover and the rotating sleeve or sealing the rear end of the core shaft and the rotating sleeve.

10. The multi-stage internal screw pump driven by a hole-type servo motor according to claim 1, characterized in that, The multi-stage inner spiral pump further includes: An annular encoder moving ring installed on the outer side wall of the rotating sleeve; An encoder reading head arranged on the inner wall of the installation cavity, and the encoder reading head is located outside the annular encoder moving ring.

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