An electric pump

Abstract

The application relates to an electric pump for a refrigeration system, which comprises a shell and an impeller installed in the shell and capable of rotating; the impeller comprises a cover disc, at least part of the shell is arranged opposite to the cover disc, a gap between the cover disc and the shell opposite to the cover disc forms a backflow channel, the electric pump has a discharge channel and an auxiliary flow channel, an outlet of the auxiliary flow channel is located on a wall corresponding to the backflow channel, and the auxiliary flow channel is communicated with the discharge channel and the backflow channel. By arranging the auxiliary flow channel, the fluid flowing out of the auxiliary flow channel generates convection with the fluid in the backflow channel, generates certain resistance to the fluid in the backflow channel, reduces the backflow of the fluid in the backflow channel, and thus improves the efficiency of the electric pump to a certain extent.

Description

Technical Field

[0001] This application relates to the field of thermal management technology, and in particular to an electric pump for driving coolant flow in a thermal management system. Background Technology

[0002] It is known that the pump inlet is guided to the center of the impeller. The fluid located at the center of the impeller reaches the working blades and is delivered to the pump outlet through the discharge channel as the impeller rotates. There is a gap between one side of the impeller cover and the housing component opposite the cover. During fluid transport, this gap forms a backflow channel that guides fluid from the discharge channel to the pump inlet. Some fluid flows out of the pump inlet along the backflow channel, which leads to a decrease in pump efficiency. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide an electric pump that can relatively reduce fluid backflow and improve the pump's transmission efficiency to a certain extent. The specific technical solution is as follows:

[0004] An electric pump includes a housing and an impeller mounted within the housing and rotatable; the impeller includes a cover plate, at least a portion of the housing is disposed opposite to the cover plate, a gap between the cover plate and the housing formed a return flow channel, the electric pump has a discharge channel and an auxiliary flow channel, the outlet of the auxiliary flow channel is located on the wall corresponding to the return flow channel, and the auxiliary flow channel connects the discharge channel and the return flow channel.

[0005] The electric pump provided by the above technical solution has an auxiliary flow channel that connects the discharge channel and the return channel. The fluid flowing out through the auxiliary flow channel forms a convection with the fluid in the return channel, which generates a certain resistance to the fluid in the return channel, thereby reducing the fluid from flowing back from the return channel and thus improving the efficiency of the electric pump to a certain extent.

[0006] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a cross-sectional structural schematic diagram of the impeller of the electric pump according to an embodiment of this application;

[0009] Figure 2 This is an exploded structural diagram of the impeller of the electric pump according to an embodiment of this application;

[0010] Figure 3 This is a schematic cross-sectional view of an electric pump according to an embodiment of this application;

[0011] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0012] Figure 5 yes Figure 3 A partial structural diagram showing that the axis of the auxiliary flow channel outlet is at 90° to the axis of the return flow channel;

[0013] Figure 6 yes Figure 3 A partial structural diagram showing that the axis of the auxiliary flow channel outlet is 180° to the axis of the return flow channel.

[0014] Figure 7 for Figure 3 Enlarged schematic diagram at point A (showing the composition of the reflux channel);

[0015] Figure 8 This is a schematic cross-sectional view of another electric pump according to an embodiment of this application;

[0016] Figure 9 yes Figure 8 Enlarged view of point B in the middle;

[0017] Figure 10 yes Figure 8 A partial structural diagram showing that the axis of the auxiliary flow channel outlet is at 90° to the axis of the return flow channel;

[0018] Figure 11 yes Figure 8 A partial structural diagram showing that the axis of the auxiliary flow channel outlet is 180° to the axis of the return flow channel.

[0019] Figure 12 This is a schematic cross-sectional view of another electric pump according to an embodiment of this application;

[0020] Figure 13 yes Figure 12 Enlarged schematic diagram at point C (showing the staggered arrangement of the first auxiliary flow channel outlet and the second auxiliary flow channel outlet);

[0021] Figure 14 yes Figure 12 A partial structural diagram showing the first auxiliary flow channel outlet and the second auxiliary flow channel outlet positioned opposite each other.

[0022] icon:

[0023] 1-Electric pump; 10-Pump shaft; 11-Impeller; 111-Blade; 112-Cover plate; 113-Support plate; 1131-Blade slot; 1132-Pump shaft mounting hole; 114-Inlet end; 1141-Inlet end face; 12-First housing; 121-Pump inlet; 122-Pump outlet; 123-Discharge channel; 13-Return channel; 131-Transverse flow channel; 132-Transition flow channel; 133-Annular flow channel; 14-Auxiliary flow channel; 141-First extension section at the end; 142-Second extension section at the end; 143-Auxiliary flow channel inlet; 144-Auxiliary flow channel outlet; 15-First auxiliary flow channel; 151-First auxiliary flow channel inlet; 152-First auxiliary flow channel outlet; 16-Second auxiliary flow channel; 161-Second auxiliary flow channel inlet; 162-Second auxiliary flow channel outlet. Detailed Implementation

[0024] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0025] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0026] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0027] See Figure 3 and combined Figure 1 and Figure 2As shown, an embodiment of this application proposes an electric pump 1, including a housing, an impeller 11, and a pump shaft 10. The impeller 11 and the pump shaft 10 are installed inside the housing, and the impeller 11 is driven by the pump shaft 10 to rotate within the housing. The impeller 11 includes a cover plate 112, a support plate 113, and blades 111. The blades 111 protrude from the support plate 113, and the upper end surface of the support plate 113 has multiple blade slots 1131. Parts of the blades 111 are embedded in the blade slots 1131 and fixedly connected to the support plate 113. The support plate 113 is provided with a pump shaft mounting hole 1132, and the pump shaft 10 is installed in the pump shaft mounting hole 1132 and is limitedly connected to the pump shaft mounting hole 1132 (e.g., keyed connection). The pump shaft 10 and the pump shaft mounting hole 1132 are coaxially arranged so that the rotation of the pump shaft 10 (which can be driven by a motor) can drive the support plate 113 to rotate, thereby driving the blades 111 to rotate. The end of the blade 111 away from the support plate 113 is the free end. The cover plate 112 is connected to the free end of the blade 111 and rotates together with the blade 111.

[0028] See Figure 3 As shown and combined Figure 1 As shown, the electric pump 1 has a pump inlet 121 and a pump outlet 122. The impeller 11 is positioned at an inlet end 114 corresponding to the pump inlet 121. The inlet end 114 includes an inlet end face 1141 facing the pump inlet 121. Fluid enters the casing through the pump inlet 121 and passes through the inlet end 114 of the impeller 11 to enter the center of the impeller 11. After being centrifugally rotated by the blades 111, the fluid is output radially outward along the impeller 11. A discharge channel 123 is formed circumferentially on the radially outer side of the impeller 11 inside the casing. The discharge channel 123 connects to the pump outlet 122. Fluid enters the discharge channel 123 after being rotated by the impeller 11 and then flows out from the pump outlet 122.

[0029] See Figure 3 and combined Figure 4As shown, at least part of the housing is positioned opposite to the cover plate 112, and the gap between the cover plate 112 and the housing opposite it forms a return channel 13. The return channel 13 connects the discharge channel 123 and the inlet channel of the electric pump 1. When the electric pump 1 is working, the pump shaft 10 drives the impeller 11 to rotate. Fluid enters the housing through the pump inlet 121 and is guided to the center of the blades 111. Under the rotation of the blades 111, the fluid flows radially along the blades 111 to the discharge channel 123, and is then transported to the pump outlet 122 from the discharge channel 123. Due to the effect of inertial centrifugal force, the fluid is in a low-pressure area at the center of the impeller 11 corresponding to the pump inlet 121, while the fluid pressure in the discharge channel 123 is higher, making the discharge channel 123 a high-pressure area. Under the pressure difference between the center of the blades 111 and the discharge channel 123, some of the fluid in the discharge channel 123 will enter the return channel 13 and flow from the return channel 13 to the inlet channel of the electric pump 1, which will lead to a decrease in the efficiency of the electric pump 1.

[0030] See Figures 3 to 14 As shown, in this embodiment of the electric pump 1, an auxiliary flow channel is provided on the physical structure corresponding to the wall of the return channel 13 (for example, the housing or cover plate 112, which will be specifically described below). The auxiliary flow channel includes an auxiliary flow channel 14, which connects the discharge channel 123 and the return channel 13. Some of the fluid in the discharge channel 123 enters the auxiliary flow channel 14 and flows to the return channel 13 via the auxiliary flow channel 14. The fluid flowing to the return channel 13 via the auxiliary flow channel 14 forms convection with the fluid in the return channel 13, generating a certain resistance to the fluid in the return channel 13, thereby reducing the fluid from flowing back from the return channel 13 and thus improving the efficiency of the electric pump 1 to a certain extent.

[0031] The following embodiments will further illustrate the structural principle of the electric pump of this application in conjunction with the specific setting location of the auxiliary flow channel.

[0032] like Figures 3 to 7As shown, the auxiliary flow channel 14 of the electric pump 1 in this embodiment can be disposed in the housing. Specifically, the housing includes a first housing 12 and a second housing, which can be fastened together with fasteners to form the housing. The first housing 12 is disposed opposite to the cover plate 112, that is, the inner wall surface of the first housing 12 and the upper surface of the cover plate 112 face each other. The gap between the inner wall surface of the first housing 12 and the upper surface of the cover plate 112 forms a return channel 13. The discharge channel 123 is correspondingly disposed between the inner wall surface of the first housing 12 and the radial edge of the cover plate 112. The auxiliary flow channel 14 is disposed in the first housing 12 and extends radially (not absolutely radial, but radially or nearly) within the first housing 12. The radial extension trend can be defined as radial extension). The auxiliary flow channel 14 includes an auxiliary flow channel inlet 143 and an auxiliary flow channel outlet 144. The auxiliary flow channel inlet 143 is located on the inner wall of the first housing 12 corresponding to the discharge channel 123 and is connected to the discharge channel 123. The auxiliary flow channel outlet 144 is located on the inner wall of the first housing 12 corresponding to the return channel 13 and is connected to the return channel 13, so that the auxiliary flow channel 14 connects the discharge channel 123 and the return channel 13.

[0033] Along the circumference of the first housing 12, the auxiliary flow channel 14 extends inside the first housing 12 to penetrate part or all of the circumference of the first housing 12. That is, along the circumference of the first housing 12, the auxiliary flow channel 14 can be formed as an incomplete annular flow channel or a complete annular flow channel inside the first housing 12. An incomplete annular flow channel means that on the radial cross section of the electric pump 1 in this embodiment, the circumferential angle of the auxiliary flow channel 14 in the projection of the cross section is less than 360°. A complete annular flow channel means that on the radial cross section of the electric pump 1 in this embodiment, the circumferential angle of the auxiliary flow channel 14 in the projection of the cross section is equal to 360°.

[0034] When molding the auxiliary flow channel 14, the first housing 12 can be configured as a split structure. For example, the first housing 12 includes at least two first split parts, such as two, three, or more. The at least two first split parts can be injection molded separately for easy demolding. The molded at least two first split parts are then joined together to form the auxiliary flow channel 14. The at least two first split parts are fixedly connected, and the connection method can be welding. Specifically, the first housing 12 may include two first split parts, and the two first split parts are joined together to form the auxiliary flow channel 14.

[0035] Specifically, see Figures 4 to 6As shown, the auxiliary flow channel 14 disposed in the first housing 12 includes a plurality of sequentially connected first extension sections. The first extension section connecting the auxiliary flow channel outlet 144 is defined as the terminal first extension section 141. The axial direction of the terminal first extension section 141 is the fluid outflow direction of the auxiliary flow channel outlet 144. Figures 4 to 6 The arrow direction at the outlet 144 of the auxiliary flow channel and the axial direction of the return channel 13 ( Figures 4 to 6 The angle of the arrow in the return channel 13 is 90°, 180°, or any degree between 90° and 180°. For example... Figure 5 The diagram shows a structure where the axial direction of the first extension section 141 at the end is at a 90° angle to the axial direction of the return channel. Figure 6 The diagram shows a structure in which the axial direction of the first extension section 141 at the end is at an angle of 180° to the axial direction of the return channel 13. Figure 4 The diagram shows a structural form where the axial direction of the first extension section 141 at the end is at an angle between 90° and 180° to the axial direction of the return channel 13.

[0036] Of course, the structure, position and form of the auxiliary flow channel 14 are not limited to this. The shape of the auxiliary flow channel 14 formed by connecting multiple first extensions can be any shape, as long as the following limitations on the fluid pressure flowing out of the auxiliary flow channel 14 and the fluid pressure in the return channel 13 are met.

[0037] See Figures 8 to 11 As shown, the auxiliary flow channel 14 of the electric pump 1 in this embodiment can be disposed in the cover plate 112. Specifically, the auxiliary flow channel 14 is disposed in the cover plate 112 and extends radially along the cover plate 112 (not absolutely radial, but having a tendency to extend radially or nearly radially can be defined as radial extension). The auxiliary flow channel 14 includes an auxiliary flow channel inlet 143 and an auxiliary flow channel outlet 144. The auxiliary flow channel inlet 143 is disposed in the radial outer wall of the cover plate 112 and is connected to the discharge channel 123. The auxiliary flow channel outlet 144 is disposed in the wall of the cover plate 112 corresponding to the return channel 13 and is connected to the return channel 13, so that the auxiliary flow channel 14 is connected to the discharge channel 123 and the return channel 13.

[0038] Along the circumference of the cover plate 112, the auxiliary flow channel 14 extends inside the cover plate 112 to penetrate part or all of the circumference of the cover plate 112. That is, along the circumference of the cover plate 112, the auxiliary flow channel 14 can be formed as an incomplete annular flow channel or a complete annular flow channel inside the cover plate 112. An incomplete annular flow channel means that on the radial section of the electric pump 1 in this embodiment, the circumferential angle of the auxiliary flow channel 14 is less than 360°. A complete annular flow channel means that on the radial section of the electric pump 1 in this embodiment, the circumferential angle of the auxiliary flow channel 14 is equal to 360°.

[0039] When molding the auxiliary runner 14, the cover plate 112 can be configured as a split structure. For example, the cover plate 112 includes at least two second split parts, such as two, three, or more. The at least two second split parts can be injection molded separately for easy demolding. After molding, the at least two second split parts are joined together to form the auxiliary runner 14. The at least two second split parts are fixedly connected, and the connection method can be welding. Specifically, the cover plate 112 may include two second split parts, and the two second split parts are joined together to form the auxiliary runner 14.

[0040] Specifically, see Figures 9 to 11 As shown, the auxiliary flow channel 14 disposed on the cover plate 112 includes a plurality of sequentially connected second extension sections. The second extension section connecting the auxiliary flow channel outlet 144 is defined as the terminal second extension section 142. The axial direction of the terminal second extension section 142 is the fluid outflow direction of the outlet of the auxiliary flow channel 14. Figures 9 to 11 The arrow direction at the outlet 144 of the auxiliary flow channel and the axial direction of the return channel 13 ( Figures 9 to 11 The angle of the arrow in the return channel is 90°, 180°, or any degree between 90° and 180°. For example... Figure 10 The diagram shows a structure where the axial direction of the second extension section 142 at the end is at a 90° angle to the axial direction of the return channel 13. Figure 11 The diagram shows a structure where the axial direction of the second extension section 142 at the end is at an angle of 180° to the axial direction of the return channel 13. Figure 9 The diagram shows a structure in which the axial direction of the second extension section 142 at the end is at an angle between 90° and 180° to the axial direction of the return channel 13.

[0041] Of course, the structure, position and form of the auxiliary flow channel 14 are not limited to this. The shape of the auxiliary flow channel 14 formed by connecting multiple second extensions can be any shape, as long as the following limitations on the fluid pressure flowing out of the auxiliary flow channel 14 and the fluid pressure in the return channel 13 are met.

[0042] It should be further explained that in the auxiliary flow channel 14 and the return flow channel 13, the fluid usually flows along the axial direction of each flow channel, that is, the axial direction of the flow channel is consistent with the flow direction of the fluid in the flow channel. In order to make the fluid flowing from the auxiliary flow channel 14 to the return flow channel 13 form a convection effect with the fluid in the return flow channel 13, the embodiments of this application adjust the relative angle between the axis of the auxiliary flow channel outlet 144 and the axis of the return flow channel 13 to achieve the convection effect between the fluid in the return flow channel and the auxiliary flow channel. Specifically, in the embodiments of this application, in the projection of the axial section of the pump shaft 10, the axis of the auxiliary flow channel outlet 144 (that is, the axis corresponding to the axis of the first end extension 141 and the second end extension 142) and the axis of the return flow channel 13 are at an angle of 90° to 180°, that is, the axis of the auxiliary flow channel outlet 144 and the axis of the return flow channel 13 can be 90° or 180° or any angle between 90° and 180°. Therefore, if the fluid flow direction of the return channel 13 is defined as the first direction, and the first direction is at an angle of 90°-180° to the fluid outflow direction of the auxiliary channel outlet 144, at this angle, the fluid flowing out of the auxiliary channel outlet 144 and the fluid in the return channel 13 will have a counteracting effect, thereby reducing the backflow of fluid from the return channel 13. In the projection of the axial section of the pump shaft 10, the optimal structure is for the axis of the auxiliary channel outlet 144 (i.e., the axis corresponding to the aforementioned first extension section 141 and second extension section 142 at the end) and the axis of the return channel 13 to be at 180°. Under this structure, the fluid flowing out of the auxiliary channel 14 and the fluid in the return channel 13 achieve a counteracting effect in opposite directions, maximizing the resistance to the fluid in the return channel 13 and best reducing the backflow of fluid in the return channel 13, thereby maximizing the efficiency of the electric pump 1.

[0043] Furthermore, the effectiveness of the fluid flowing out of the auxiliary channel 14 impacting the fluid in the return channel 13 depends not only on the fluid flow direction but also on the fluid pressure. A better convection impact effect is achieved when the fluid pressure flowing out of the auxiliary channel 14 is the same as or nearly the same as the fluid pressure in the return channel 13. Therefore, to further improve the effectiveness of the convection effect of the fluid flowing out of the auxiliary channel 14 on the fluid in the return channel 13, this embodiment defines the flow pressure of the fluid in the return channel 13 as a first pressure, and sets the first pressure to be close to the fluid pressure at the auxiliary channel outlet 144, ideally the two pressures being the same. When the two pressures are the same and the angle between the first direction and the fluid flow direction at the auxiliary channel outlet 144 is 180°, the fluid flowing out of the auxiliary channel 14 and the fluid in the return channel 13 achieve a counter-impact effect with opposite directions and the same pressure, theoretically completely preventing the fluid in the return channel 13 from flowing from the discharge channel 123 to the pump inlet 121.

[0044] To ensure that the first pressure and the fluid pressure at the auxiliary flow channel outlet 144 are nearly identical, the dimensions and other parameters of the auxiliary flow channel 14 and the return flow channel 13 can be designed in a correlated manner. For example, the lengths of the auxiliary flow channel 14 and the return flow channel 13 can be set to be the same or nearly the same along the axis of the flow channel, and the dimensions and shapes of the auxiliary flow channel 14 and the return flow channel 13 can also be the same or nearly the same along the axial and circumferential directions of the impeller. See, for example... Figure 3 The projection of the cross-section along the axis of the pump shaft 10 shown is illustrated. The length of the return channel 13 along its axial direction is L1, and the length of the auxiliary channel 14 along its axial direction is L2. The lengths of both can be set to L. 1, Same length as L2; ​​see also Figure 3 As shown in the projection of the cross section along the axial direction of the pump shaft 10, the width W1 of the auxiliary flow channel 14 and the width W2 of the return flow channel 13 can be set to correspond and be consistent along the axial direction of the impeller 11. In the projection of the radial cross section perpendicular to the axis of the pump shaft 10, the lengths of the auxiliary flow channel 14 and the return flow channel 13 correspond and are consistent along the circumference of the impeller 11, ensuring that the overall shape and size of the auxiliary flow channel 14 and the return flow channel 13 are consistent to guarantee pressure consistency. Furthermore, the roughness of the inner walls of the auxiliary flow channel 14 and the return flow channel 13 is the same or tends to be the same, and the molding materials of the auxiliary flow channel 14 and the return flow channel 13 are the same or have similar properties. The fundamental purpose is to adjust the structural parameters of the auxiliary flow channel 14 and the return flow channel 13 so that the aforementioned first pressure and the fluid pressure at the outlet 144 of the auxiliary flow channel tend to be the same, thereby improving the effectiveness of the convection effect of the fluid flowing out of the auxiliary flow channel 14 on the fluid in the return flow channel 13. Of course, if one or more structural parameters of the auxiliary flow channel 14 and the return flow channel 13 are different, but the overall effect of multiple parameters makes the first pressure and the fluid pressure at the outlet of the auxiliary flow channel 144 tend to be the same, this is also within the feasible range of this embodiment.

[0045] Furthermore, when the angle between the first direction and the fluid outflow direction of the auxiliary flow channel outlet 144 is 90° or any angle between 90° and 180°, and the first direction and the fluid outflow direction of the auxiliary flow channel outlet 144 are not completely opposite, the fluid pressure at the auxiliary flow channel outlet 144 is not entirely able to impact the fluid in the return channel 13. Therefore, this structure allows the fluid pressure at the auxiliary flow channel outlet 144 to be greater than the first pressure to a certain extent, thereby improving the effectiveness of the impact of the fluid flowing out of the auxiliary flow channel 14 on the fluid in the return channel 13. However, the fluid pressure at the outlet of the auxiliary flow channel 14 should not be too high to avoid affecting the normal operation of the electric pump 1.

[0046] Additionally, see also Figure 7 As shown, as described above, along the axial direction of the return channel 13 ( Figure 7The direction of the return channel 13 is defined by the dashed line extending along the axial direction of the return channel 13. The length of the return channel is L1 (the overall length along the axial direction of the return channel 13). The end face of the impeller 11 at the inlet end 114 corresponding to the pump inlet is the inlet end face 1141. The axis of the auxiliary flow channel outlet 144 is defined. Figure 7 (The dashed line at the auxiliary flow channel outlet 144) and the inlet end face 1141 ( Figure 7 The dotted line corresponding to the inlet end face 1141 has a preset distance L (the length between the axis of the flow channel outlet 144 and the inlet end face 1141 along the axis of the return channel 13), and L and L1 satisfy L≥1 / 3L1, so that the auxiliary flow channel outlet 144 and the inlet end face 1141 of the impeller 11 have a certain distance. This distance plays a buffering role for the fluid in the return channel 13, and avoids the fluid pressure change after the fluid flowing out through the auxiliary flow channel outlet 144 interacts with the convection in the return channel 13 from affecting the fluid at the pump inlet 121. For example, since the pump inlet 121 is a low-pressure area, if the fluid flowing out through the auxiliary flow channel 14 has a higher pressure, after convection with the fluid in the return flow channel 13, the pressure in the return flow channel 13 will still be greater than the pressure at the pump inlet 121. This will cause the fluid entering from the pump inlet 121 to directly enter the return flow channel 13, affecting the normal operation of the electric pump 1. Therefore, a predetermined distance is reserved between the outlet of the auxiliary flow channel 14 and the end of the impeller 11 near the pump inlet 121. This can, to a certain extent, avoid the impact of pressure changes after the convection between the return flow channel 13 and the auxiliary flow channel 14 on the fluid at the pump inlet 121, thereby improving the stability of the electric pump 1. Specifically, L and L1 are set to satisfy L≥1 / 3L1, that is, the distance between the outlet 144 of the auxiliary flow channel and the inlet end face 1141 of the impeller 11 is at least greater than or equal to 1 / 3 of the total length of the return flow channel, thus providing sufficient buffer space for the fluid in the return flow channel 13.

[0047] Specifically, see Figure 7As shown, the return channel 13 includes a transverse flow channel 131, an annular flow channel 133, and a transition flow channel 132. The transition flow channel 132 is disposed between the transverse flow channel 131 and the annular flow channel 133 and connects the transverse flow channel 131 and the annular flow channel 133. Projecting the cross-section of the pump shaft 10 along its axis, the vertical section along the axial direction of the pump shaft 10 corresponds to an annular flow channel 133, and the axis of the annular flow channel 133 coincides with the axis of the pump shaft 10. The transverse section along the radial direction of the impeller 11 corresponds to a transverse flow channel 131, and the curved section connecting the vertical and transverse sections corresponds to a transition flow channel 132. The auxiliary flow channel outlet 144 is located on the wall corresponding to the transverse flow channel 131. There are a transition flow channel 132 and an annular flow channel 133 between the auxiliary flow channel outlet 144 and the inlet end face 1141 of the impeller 11. The transition flow channel 132 and the annular flow channel 133 effectively buffer the fluid in the return channel 13. Thus, the change in fluid pressure after the fluid flowing out through the auxiliary flow channel outlet 144 interacts with the convection in the return channel 13 will not affect the fluid at the pump inlet 121, thereby improving the stability and reliability of the electric pump 1.

[0048] In addition, such as Figures 12 to 14 As shown, the auxiliary flow channel 14 of the electric pump in this embodiment can also be simultaneously disposed in the housing and the cover plate 112. Specifically, the auxiliary flow channel 14 includes a first auxiliary flow channel 15 and a second auxiliary flow channel 16. The first auxiliary flow channel 15 is disposed in the first housing 12, and has the same structural form as the auxiliary flow channel disposed in the first housing 12 described above. The first auxiliary flow channel 15 includes a first auxiliary flow channel inlet 151 and a first auxiliary flow channel outlet 152. The first auxiliary flow channel inlet 151 is disposed in the inner wall portion of the first housing 12 corresponding to the discharge channel 123, and the first auxiliary flow channel outlet 152 is disposed in the inner wall portion of the first housing 12 corresponding to the return channel 13. The first auxiliary flow channel inlet 151 is connected to the discharge channel 123, and the first auxiliary flow channel outlet 152 is connected to the return channel 13, so that the first auxiliary flow channel 15 is connected to the discharge channel 123 and the return channel 13.

[0049] Furthermore, similar to the structure of the auxiliary flow channel 14 within the first housing 12, the first auxiliary flow channel 15 can also extend circumferentially through the entire circumferential portion of the first housing 12. The structure of the first housing 12 can also be designed as a split structure, for example, by combining multiple injection-molded split parts together to form the first auxiliary flow channel 15.

[0050] The second auxiliary flow channel 16 is disposed on the cover plate 112 and has the same structural form as the auxiliary flow channel 14 disposed on the cover plate 112. The second auxiliary flow channel 16 includes a second auxiliary flow channel inlet 161 and a second auxiliary flow channel outlet 162. The second auxiliary flow channel inlet 161 is disposed on the radial outer wall of the cover plate 112, and the second auxiliary flow channel outlet 162 is disposed on the wall of the cover plate 112 corresponding to the return channel 13. The second auxiliary flow channel inlet 161 is connected to the discharge channel 123, and the second auxiliary flow channel outlet 162 is connected to the return channel 13, so that the second auxiliary flow channel 16 connects the discharge channel 123 and the return channel 13.

[0051] The structure and operating principle of the first auxiliary flow channel 15 are the same as those of the auxiliary flow channel 14 provided on the shell, and the structure and operating principle of the second auxiliary flow channel 16 are the same as those of the auxiliary flow channel 14 provided on the cover plate. Therefore, the positions of the first auxiliary flow channel outlet 152 of the first auxiliary flow channel 15 and the second auxiliary flow channel outlet 162 of the second auxiliary flow channel 16 can also be correspondingly set on the wall portion of the transverse flow channel. However, it should be noted that when two auxiliary flow channels 14 are provided, the first auxiliary flow channel outlet 152 and the second auxiliary flow channel outlet 162 can be arranged opposite to each other or staggered. Figure 14 As shown, when the first auxiliary flow channel outlet 152 and the second auxiliary flow channel outlet 162 are arranged opposite each other, the fluids flowing out of the first auxiliary flow channel 152 and the second auxiliary flow channel 162 into the return channel 13 together exert a convection effect on the fluids in the return channel 13. The sum of the fluid pressure at the first auxiliary flow channel outlet 152 and the fluid pressure at the second auxiliary flow channel outlet 162 tends to be the same as the first pressure, so as to more completely impede the convection of the fluids in the return channel 13. Figure 13 As shown, when the first auxiliary flow channel outlet 152 and the second auxiliary flow channel outlet 162 are staggered, the fluids in the first auxiliary flow channel 15 and the second auxiliary flow channel 16 respectively generate convection with the fluid in the return channel 13. For example, the fluid in the return channel 13 can first generate convection with the fluid flowing out through the first auxiliary flow channel, reducing the fluid in the return channel 13 by a portion. The remaining fluid then generates convection with the fluid flowing out through the second auxiliary flow channel, further reducing the fluid in the return channel 13. Alternatively, the fluid in the return channel 13 can first generate convection with the fluid flowing out through the second auxiliary flow channel 16, and then with the fluid flowing out through the first auxiliary flow channel 15. Through the combined action of the first auxiliary flow channel 15 and the second auxiliary flow channel 16, convection can also be achieved for the fluid in the return channel 13.

[0052] The outlet angles of the two auxiliary flow channels are set in the same way as the angles of the auxiliary flow channels with the return flow channel when they are individually on the housing or cover plate, and will not be repeated here.

[0053] It should be noted that the fluid transported by the pump in this embodiment can be a liquid, such as water. In this case, the pump in this embodiment can be used as a water pump. Of course, the fluid can also be other forms of media that can be transported.

[0054] Furthermore, the electric pump of this embodiment can be used in thermal management systems, and is particularly suitable for the circulation and transportation of fluids such as coolant acting on the thermal management system.

[0055] In summary, the electric pump of this embodiment draws out the isobaric fluid by setting an auxiliary flow channel on the housing or cover plate. The fluid outlet faces and penetrates the inner wall of the return channel. The fluid convection generates a certain resistance to the fluid in the return channel, thereby reducing fluid backflow. This does not affect the pump speed and does not cause wear on the housing and cover plate. It effectively improves the efficiency and stability of the electric pump.

[0056] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in this application, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of this application, and should all be covered within the protection scope of this application.

Claims

1. An electric pump (1) comprising a housing and an impeller (11) mounted within the housing and rotatable therein; the impeller (11) includes a cover plate (112), at least a portion of the housing is disposed opposite to the cover plate (112), and a gap between the cover plate (112) and the housing disposed opposite thereto forms a return flow channel (13), characterized in that, The electric pump (1) has a discharge channel (123) and an auxiliary flow channel (14). The outlet of the auxiliary flow channel (14) is located on the wall corresponding to the return channel (13), and the auxiliary flow channel (14) connects the discharge channel (123) and the return channel (13).

2. The electric pump (1) according to claim 1, characterized in that, The housing disposed opposite to the cover plate (112) is defined as the first housing (12), and the first housing (12) is provided with the auxiliary flow channel (14); The auxiliary flow channel (14) includes an auxiliary flow channel inlet (143) and an auxiliary flow channel outlet (144). The auxiliary flow channel inlet is located on the inner wall of the first housing (12) corresponding to the discharge channel (123), and the auxiliary flow channel outlet is located on the inner wall of the first housing (12) corresponding to the return channel (13).

3. The electric pump (1) according to claim 2, characterized in that, Along the circumferential direction of the first housing (12), the auxiliary flow channel (14) extends inside the first housing (12) to a portion or all of the circumferential direction of the first housing (12); and / or The first housing (12) is a split structure, which includes at least two first split parts, and the at least two first split parts together form the auxiliary flow channel (14).

4. The electric pump (1) according to claim 1, characterized in that, The cover plate (112) is provided with the auxiliary flow channel (14); The auxiliary flow channel (14) includes an auxiliary flow channel inlet (143) and an auxiliary flow channel outlet (144). The auxiliary flow channel inlet (143) is located on the radial outer wall of the cover plate (112), and the auxiliary flow channel outlet (144) is located on the wall of the cover plate (112) corresponding to the return channel (13).

5. The electric pump according to claim 4, characterized in that, Along the circumference of the cover plate (112), the auxiliary flow channel (14) extends inside the cover plate (112) to penetrate part or all of the circumference of the cover plate (112); and / or The cover plate (112) is a split structure, which includes at least two second split parts, and the at least two second split parts together form the auxiliary flow channel (14).

6. The electric pump (1) according to any one of claims 2 to 5, characterized in that, The electric pump (1) includes a pump shaft (10). In the projection of the axial section of the pump shaft (10), the axis of the auxiliary flow channel outlet and the axis of the return channel (13) are at an angle of 90°-180°.

7. The electric pump (1) according to claim 6, characterized in that, The impeller (11) includes an inlet end (114), the inlet end (114) includes an inlet end face (1141), the length of the return channel (13) is L1 along the axial direction of the return channel (13), and the axis of the auxiliary flow channel outlet (144) is defined to have a preset distance L with the inlet end face (1141) satisfying: L≥1 / 3L1.

8. The electric pump (1) according to claim 6, characterized in that, The return channel (13) includes a transverse flow channel (131), an annular flow channel (133), and a transition flow channel (132). The transition flow channel (132) is disposed between the transverse flow channel (131) and the annular flow channel (133) and connects the transverse flow channel (131) and the annular flow channel (133). The axis of the annular flow channel (133) is parallel to the axis of the pump shaft (10). The auxiliary flow channel outlet (144) is disposed on the wall corresponding to the transverse flow channel (131).

9. The electric pump (1) according to claim 1, characterized in that, The auxiliary flow channel section includes a first auxiliary flow channel section and a second auxiliary flow channel section. The first auxiliary flow channel section includes a first auxiliary flow channel (15), and the second auxiliary flow channel section includes a second auxiliary flow channel (16). The first auxiliary flow channel (15) connects the discharge channel (123) and the return channel (13), and the second auxiliary flow channel (16) connects the discharge channel (123) and the return channel (13). The housing opposite to the cover plate (112) is defined as the first housing (12), and the first housing (12) is provided with the first auxiliary flow channel (15); the first auxiliary flow channel (15) includes a first auxiliary flow channel inlet (151) and a first auxiliary flow channel outlet (152), the first auxiliary flow channel inlet (151) is provided on the inner wall of the first housing (12) corresponding to the discharge channel (123), and the first auxiliary flow channel outlet (152) is provided on the inner wall of the first housing (12) corresponding to the return channel (13); The cover plate (112) is provided with a second auxiliary flow channel (16); the second auxiliary flow channel (16) includes a second auxiliary flow channel inlet (161) and a second auxiliary flow channel outlet (162), the second auxiliary flow channel inlet (161) is provided on the radial outer wall of the cover plate (112), and the second auxiliary flow channel outlet (162) is provided on the wall of the cover plate (112) corresponding to the return channel (13).

10. The electric pump (1) according to claim 9, characterized in that, The outlet of the first auxiliary flow channel is arranged opposite to or staggered with the outlet of the second auxiliary flow channel.

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