Pump, coolant circuit and vehicle

Abstract

The invention relates to a pump (100) for conveying a fluid from a suction-side inlet port (101) to a pressure-side outlet port (102) of the pump (100), wherein a closed impeller (120) with a cover plate (140) is arranged in a housing (110) of the pump (100) between the inlet port (101) and the outlet port (102), wherein an annular gap (150) is located between the cover plate (140) of the impeller (120) and the housing (110), in which a sealing disc (160) is arranged, which is radially centered on the inside of the housing (110) and bears against the cover plate (140) in the axial direction. Furthermore, a coolant circuit and a vehicle with such a pump (100) are proposed.

Description

[0001] The present invention relates to a pump for conveying a fluid, a coolant circuit, and a vehicle with such a pump. Background of the invention

[0002] The hydraulic unit of a pump, particularly in the case of a centrifugal pump, can have an annular gap formed between the inner contour of the pump housing and the outer surface of the impeller. This gap allows fluid to flow unintentionally back from the pump's discharge side to the suction side, resulting in hydraulic losses and a reduction in the pump's hydraulic efficiency. Ideally, the entire volume of fluid drawn in should reach the discharge side, which is prevented by the leakage in the annular gap. Typically, backflow losses of approximately 30% are accepted, and the typical efficiency of small pumps is often around 50%. Disclosure of the invention

[0003] According to the invention, a pump for conveying a fluid, a coolant circuit, and a vehicle with such a pump, comprising the features of the independent claims, are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

[0004] The invention utilizes a sealing disc to reduce leakage in the annular gap, thereby increasing the hydraulic efficiency of the pump compared to conventional pumps. For this purpose, the components of the pump housing and the impeller forming the annular gap are specially designed and shaped to provide a receptacle and sealing surface for interaction with the sealing disc. Due to the resulting higher efficiency and reduced leakage rate through the annular gap, the pump also exhibits a lower noise level during operation. Furthermore, the lower hydraulic losses allow for a corresponding reduction in the pump's rotational speed and thus its electrical power consumption, resulting in a comparatively lower current draw for the pump's electromagnetic components.Low power consumption is a major advantage, especially for vehicles that are at least partially electrically powered. Lower currents also lead to lower component temperatures, thus reducing the pump's own heat generation.

[0005] In detail, the pump according to the invention is designed to convey a fluid from a suction-side inlet port to a pressure-side outlet port of the pump, wherein a closed impeller with a cover plate is arranged in a housing of the pump between the inlet port and the outlet port, wherein an annular gap lies between the cover plate of the impeller and the housing, in which a sealing disc is arranged, which is centered on the inside of the housing in the radial direction and rests against the cover plate in the axial direction.

[0006] The impeller is a driven wheel of the pump's conveying mechanism, which, for example, has impeller blades for accelerating the fluid being pumped. A closed impeller is understood to be an impeller that has a closure at both axial ends, so that the impeller blades are not accessible from the axial direction over their entire radial area. In particular, one axial side can be completely closed, while the second axial side of the impeller is closed in a radially outer area by the aforementioned cover plate, with the cover plate leaving a radially inner area of ​​the impeller open, as this is where the fluid to be pumped is drawn in. Within the scope of this invention, the axial direction is understood to be a direction that runs parallel to the axis of rotation of the pump's impeller. A radial direction runs perpendicular to the axis of rotation of the impeller.

[0007] According to at least one embodiment, the sealing disc is designed to be forced axially towards the impeller's cover plate by fluid flowing from the pressure side to the suction side through the annular gap. This increases the sealing effect of the disc depending on the pressure differential between the pressure and suction sides. Generally, an increasing pressure differential would lead to an increasing leakage rate. By increasing the sealing effect with increasing pressure differential, this effect can be at least partially counteracted.

[0008] According to at least one embodiment, the sealing disc consists at least partially of a metal and / or a plastic. In particular, the metal and / or plastic comprises one or more materials from the group consisting of aluminum, copper, brass, steel, stainless steel, PTFE (polytetrafluoroethylene), PEEK (polyethyletherketone), PE (polyethylene), and PS (polystyrene). These are particularly advantageous materials with regard to mechanical and chemical resistance, coefficient of friction, and / or cost.

[0009] According to at least one embodiment, the cover plate has a hollow cylinder section extending axially towards the pump housing. The sealing disc is arranged within this hollow cylinder section and radially spaced from an inner wall of the hollow cylinder section. In particular, the cover plate has a sealing edge and / or sealing surface within the hollow cylinder section, which is designed to axially support the sealing disc and / or to interact with it to create a seal. This reinforces the previously described effect of increased sealing with a rising pressure difference between the pressure side and the suction side, since the fluid coming from the pressure side must act almost perpendicularly on the sealing disc to reach the suction side. This results in a particularly pronounced contact pressure of the fluid flow on the sealing disc.The sealing disc can be designed to rotate with the cover plate or to slide along the sealing edge on the cover plate. The radial spacing of the sealing disc from the inner wall of the hollow cylinder section allows for generous manufacturing tolerances without impairing the sealing effect.

[0010] Similar to the cover plate, according to at least one embodiment the housing also has a housing hollow cylinder section that projects axially in the direction of the impeller into an interior of the housing, in particular into an area radially within the hollow cylinder section of the cover plate.

[0011] The sealing washer is positioned outside the housing hollow cylinder section and radially spaced from an outer wall of the housing hollow cylinder section. This radial spacing between the sealing washer and the housing hollow cylinder section allows for relative movement between the sealing washer and the housing. Simultaneously, this clearance, or radial spacing, is the only remaining point of leakage. Accordingly, the leakage rate can be adjusted by selecting a suitable inner diameter for the sealing washer.

[0012] The coolant circuit according to the invention includes a pump according to the invention, wherein the pump is configured to pump a coolant within the coolant circuit.

[0013] The vehicle according to the invention, which can in particular be at least partially electrically powered, has a coolant circuit and / or at least one pump according to the invention. In particular, the coolant circuit is configured to regulate the temperature of a battery of the vehicle, especially a traction battery. The vehicle and the coolant circuit therefore benefit accordingly from the advantages of the pump.

[0014] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawing.

[0015] The invention is schematically illustrated in the drawing using an exemplary embodiment and is described below with reference to the drawing. Brief description of the drawings Fig. Figure 1 schematically shows an embodiment of the invention based on a perspective partial section of a pump. Fig. 2 shows the pump off Fig. 1 based on a schematic partial section in projection representation. embodiment(s) of the invention

[0016] In Fig. 1 and Fig. Figure 2 shows an embodiment of the invention by means of schematic partial sections of a pump and is generally designated as 100.

[0017] Pump 100 has an inlet port 101 on a suction side and an outlet port 102 on a pressure side. Pump 100 is a centrifugal pump and therefore has a conveying unit in the form of an impeller 120 with conveying vanes 122. The impeller 120 is rotatably mounted about an axis 130. In the example shown, the axis 130 is rigidly fixed in a receptacle in a housing 110 of pump 100, for example, by press-fitting.

[0018] The impeller 120 is designed as a closed impeller and therefore has a cover plate 140. An annular gap 150 runs between the cover plate 140 and the pump housing 110, connecting the pressure side of the pump 100 with the suction side. A sealing disc 160 is arranged in this annular gap 150 and is centered with respect to the axis 130 at a radially inner edge on an outer diameter of a housing hollow cylinder section 112 that projects into the interior of the housing 110. In the axial direction, the sealing disc 160 rests against the cover plate 140 of the impeller 120. In the example shown here, the cover plate 140 has a sealing surface or sealing edge 144 against which the sealing disc bears.

[0019] The sealing washer 160 can, for example, be manufactured as a foil stamping or a sheet metal stamping. Suitable materials for use in the sealing washer 160 include, for example, plastics such as PTFE, PEEK, PE, and PS, and metals such as aluminum, copper, steel, stainless steel, and brass, with combinations of several of these materials also being possible. In particular, a material with a low coefficient of friction can be used in the area where the sealing washer 160 contacts the sealing edge 144 and / or in an area along the inner diameter of the sealing washer 160. This minimizes the friction of the sealing washer 160, which rotates with the impeller 120, along the stationary housing hollow cylinder section 112.

[0020] During operation of pump 100, the pressure differential between the pressure side and suction side creates a flow of the pumped fluid through the remaining gap between the sealing disc 160 and the housing hollow cylinder section 112. This flow simultaneously leads to the automatic centering, lubrication, and cooling of the sealing disc 160 along the housing hollow cylinder section 112. This remaining gap, which also facilitates the installation of the sealing disc 160, represents the only remaining point of leakage through the annular gap 150. Therefore, the leakage rate through the annular gap 150 can be adjusted by appropriately selecting the inner diameter of the sealing disc 160.

[0021] In the example shown here, the cover plate 140 also has a hollow cylinder section 142 that extends axially into the housing 110. The inner diameter of the hollow cylinder section 142 is larger than the outer diameter of the sealing disc 160, so that the sealing disc 160 is located inside the hollow cylinder section 142 and spaced apart from it. This causes a deflection of the fluid flowing from the pressure side of the pump 100 through the annular gap 150 to the suction side, so that this fluid pushes the sealing disc axially towards the cover plate 140 and presses it against the sealing edge 144. This at least partially closes the annular gap 150 by means of the sealing disc 160, thereby limiting the volumetric flow rate of the leakage flow possible through the annular gap 150.

[0022] Particularly for applications without mechanical centering between the housing 110 and the conveyor or impeller 120, it can be advantageous to design the sealing disc such that its outer diameter is spaced with the largest possible radial gap from the hollow cylinder section 142 of the cover plate 140 of the impeller 120. Eccentricities between the housing 110 and the impeller 120 can thus be compensated for without the sealing disc 160 causing radial friction losses in the system. Such applications benefit particularly from the invention, since otherwise large annular gaps and thus leakage would have to be used to enable the rotation of the impeller 120.

Claims

[1] Pump (100) for pumping a fluid from a suction-side inlet port (101) to a pressure-side outlet port (102) of the pump (100), wherein a closed impeller (120) with a cover plate (140) is arranged in a housing (110) of the pump (100) between the inlet port (101) and the outlet port (102), wherein an annular gap (150) is located between the cover plate (140) of the impeller (120) and the housing (110), in which a sealing disc (160) is arranged, which is centered on the inside of the housing (110) in the radial direction and bears against the cover plate (140) in the axial direction. [2] Pump (100) according to claim 1, wherein the sealing disc (160) is arranged to be forced axially towards the cover disc (140) of the impeller (120) by fluid flowing from the pressure side to the suction side through the annular gap (150). [3] Pump (100) according to claim 1 or 2, wherein the sealing disc (160) consists at least partially of a metal and / or a plastic. [4] Pump (100) according to claim 3, wherein the metal and / or the plastic comprises one or more from the group consisting of aluminium, copper, brass, steel, stainless steel, polytetrafluoroethylene, polyethylene etherketone, polyethylene and polystyrene. [5] Pump (100) according to one of the preceding claims, wherein the cover plate (140) has a hollow cylinder section (142) extending axially in the direction of the housing (110) and the sealing disc (160) is arranged inside the hollow cylinder section (142) and radially spaced from an inner wall of the hollow cylinder section (142). [6] Pump (100) according to claim 5, wherein the cover plate (140) has a sealing edge and / or sealing surface (144) within the hollow cylinder section (142) which is configured to axially support the sealing disc (160) and / or to act sealingly with the sealing disc (160). [7] Pump (100) according to one of the preceding claims, wherein the housing (110) has a housing hollow cylinder section (112) which projects axially in the direction of the impeller (120) into an interior of the housing (110), in particular into a region radially within the hollow cylinder section (142) of the cover plate (140) according to claim 5. [8] Pump (100) according to claim 7, wherein the sealing disc (160) is arranged outside the housing hollow cylinder section (112) and radially spaced from an outer wall of the housing hollow cylinder section (112). [9] Pump (100) according to claim 8, wherein the radial spacing between sealing disc (160) and housing hollow cylinder section (112) as the only remaining leakage point in the annular gap (150) is adjustable depending on a maximum desired leakage rate by selecting a suitable inner diameter of the sealing disc (160). [10] Coolant circuit with a pump (100) according to one of the preceding claims, wherein the pump (100) is configured to pump a coolant within the coolant circuit. [11] Vehicle, in particular at least partially electrically powered vehicle, with a coolant circuit according to claim 10 and / or at least one pump (100) according to any one of claims 1 to 9. [12] Vehicle according to claim 11, wherein the coolant circuit is configured to regulate the temperature of a battery of the vehicle, in particular a traction battery.

Images