ES3058093T3 - Pump system with medium-cooled fluid pump - Google Patents

Abstract

A liquid pump with a housing (10) forming an inlet (12), a pump chamber (14), an outlet nozzle (44), and a motor chamber (30), a shaft (16) rotatably mounted in the housing, on which an impeller (18) is disposed within the pump chamber (14), and on which, in a section outside the pumped medium, a rotor (34) of an electric motor (28) is disposed, the rotor being surrounded by a stator (36) disposed in the motor chamber (30), and with a cooling jacket (40) surrounding the motor chamber, which is in fluid communication with the pump chamber (14) on one side and with the outlet nozzle (44) on the other, wherein a pressure line (20) connecting the pump chamber (14) with the cooling jacket (42) enters the cooling jacket (42) at a first circumferential position (A), and the outlet nozzle (44) is connected to the jacket. cooling (42) in a second circumferential position (B). It is characterized in that the casing (10) has a circumferential mounting flange (52) designed to mount the pump in a collection tank (22) for the fluid to be pumped, and that the mounting flange (52) is arranged at the level of the end of the cooling jacket (40) facing the pump chamber (14). (Automatic translation with Google Translate, no legal value)

Description

[0001] DESCRIPTION

[0002] Fluid-cooled liquid pumping system

[0003] The invention relates to a pumping system with a liquid collection tank, as well as a liquid pump with a housing forming a suction opening, a pumping chamber, an outlet pipe and a motor chamber, a shaft rotatably mounted in the housing, an impeller arranged inside the pumping chamber and an electric motor rotor arranged in the section outside the pumped fluid surrounded by a stator arranged in the motor chamber, wherein the liquid pump is mounted in such a way in the collection tank (22) that the shaft extends vertically and the housing with its suction opening is submerged in the liquid, while the motor chamber is above a maximum liquid level of the liquid.

[0004] Such a pumping system is known from document DE 1275362 B.

[0005] Documents JP S5397402 U and US 4747757 A describe fluid-cooled liquid pumps configured as submersible pumps, such that, under normal operating conditions, the casing, including the motor housing, is completely submerged in the liquid in the collection tank, and the motor is thus cooled by the surrounding fluid. However, since, under certain conditions, the liquid level in the collection tank may drop to the point where the motor housing is no longer submerged and is therefore no longer sufficiently cooled, the pressure pipe extending from the pump chamber of this pump is connected to a cooling jacket surrounding the motor, so that the pumped fluid flows around the motor. In this way, the motor is cooled by the pumped fluid at all times.

[0006] From documents DE 60126061 T2 and DE 20105322 U1, pumps are known in which the pumped fluid is used to cool the engine.

[0007] In contrast, air-cooled pumps are used in pumping systems where the pump is only submerged with its suction opening in the liquid to be pumped, while the part of the housing that houses the motor is always above the liquid level, since with these pumps there is no risk of liquid from the collection tank entering the air-cooling system of the pump motor.

[0008] The objective of the invention is to create a pumping system with high performance and low installation height. This objective, according to the invention, is achieved by means of a cooling jacket surrounding the motor chamber, which has a cylindrical shape and forms an annular chamber. On one side, it is in fluid connection with the pumping chamber and on the other side with the outlet pipe. A pressurized pipe, which connects the pumping chamber to the cooling jacket, opens at a first peripheral position in the cooling jacket, and the outlet pipe is connected at a second peripheral position in the cooling jacket. The first and second peripheral positions are located diametrically opposite each other.

[0009] The fundamental idea of the solution according to the invention is that even in pumping systems, where an air-cooled pump could be used safely, a fluid-cooled pump with a cooling jacket surrounding the motor is used.

[0010] The advantage of this solution is that even with pumps that may experience a high continuous load, no fan is needed to generate a cooling airflow and therefore the installation height, measured from the bottom of the collection tank to the top of the pump housing, can be significantly reduced.

[0011] The first and second perimeter positions of the cooling jacket are located diametrically opposite each other. From the pressurized pipe, the fluid then branches into two streams, which flow around the engine chamber in opposite directions of rotation and join together upon entering the outlet pipe.

[0012] Advantageous configurations and improvements of the invention are specified in the dependent claims.

[0013] The pressurized pipe enters the lower end of the cooling jacket, while the outlet pipe is preferably arranged radially from the upper end of the cooling jacket, so that the fluid flow in the cooling jacket also has an upward component. This prevents the formation of areas with low fluid exchange in the cooling jacket and, at the same time, facilitates air purging from the pump.

[0014] An example of implementation is explained in more detail below using a drawing.

[0015] They show:

[0016] Figure 1 shows an axial section using a pumping system according to an exemplary embodiment of the invention; and

[0017] Figure 2, a section along line II-II in Figure 1.

[0018] The pump shown in Figure 1 shows a casing 10 forming a suction opening 12 in the area of its lower end and a pumping chamber 14 above it. A shaft 16 is rotatably mounted in the casing 10 and carries at least one impeller 18 inside the pumping chamber 14. In the example shown, a cascade of three radial impellers is provided, which transport the fluid drawn in through the suction opening 12, for example, a coolant, to a pressure pipe 20 which starts from an upper end of the pumping chamber 14 in a position radially displaced with respect to the shaft 16.

[0019] In the example shown, the pump is mounted in a coolant collection tank 22 such that the shaft 16 is vertically oriented and the suction opening 12 is sealed against the bottom 24 of the collection tank 22. The liquid level 26 in the collection tank 22 is indicated by a dashed line. The pump is submerged in the coolant with its lower portion, which forms the suction opening 12, the pumping chamber 14, and the lower part of the pressure pipe 20, while the upper portion of the pump is above the liquid level 26. This upper portion of the housing 10 contains an electric motor 28, which is thus better protected from the harmful effects of the pumped fluid.

[0020] The shaft 16 is mounted with its section located above the liquid level 26 by means of axially fixed rolling bearings 29 in the housing 10 and passes through a motor chamber 30 that is closed at the upper end by a cover 32. An electric motor rotor 34 is arranged inside the motor chamber 30 fixed to rotation on the shaft 16 and is surrounded by a stator 36 that is held stationary in the motor chamber 30 and is held through its outer perimeter surface in thermal contact with a perimeter wall 38 of the motor chamber.

[0021] The motor chamber 30 is surrounded along most of its height by a cooling jacket 40, the walls of which are integral with the perimeter wall 38 of the motor chamber. The cooling jacket 40 is generally cylindrical and forms an annular chamber 42. The pressure pipe 20 opens at a first perimeter position A, seen on the right in Figure 1, at the lower end of the annular chamber 42. At a perimeter position B located diametrically opposite the first perimeter position A, seen on the left in Figure 1, a radially branching outlet pipe 44 is connected at the upper end of the cooling jacket 40. The fluid pumped by the pump flows through this outlet pipe to a delivery pipe not shown. However, the outlet pipe is located below the upper stator coil heads, which in this example protrude above the cooling jacket. Therefore, the outlet tube can be arranged at the top end of the cooling jacket for better air purging without increasing the pump's installation height.

[0022] When the pump is in operation, the fluid is drawn in through the suction opening 12 and forced through the pressure pipe 20 into the annular chamber 42 of the cooling jacket 40. At the first periphery position A, the fluid flow splits into two branches that flow around the motor chamber 30 in opposite directions and rejoin at periphery position B, as indicated by the arrows in Figure 2.

[0023] The fluid flowing through the annular chamber 42 in the example shown here forms a closed body of water around the pump motor, which is not interrupted by any acoustic bridge, thereby achieving good sound insulation and, consequently, very quiet operation of the pump.

[0024] In an embodiment not corresponding to the invention, the outlet of the pressure pipe 20 and the transition to the outlet pipe could also be located close to each other and separated by a partition wall.

[0025] In height, the cooling jacket 42 can be sized so that the stator coil packs 36 are cooled in a directed manner.

[0026] As shown in Figure 1, the motor chamber 30, which also houses the roller bearing 29 for the shaft 16, is sealed by a shaft seal 46 against the inside of the collection tank 22. Optionally, the pump may be equipped with a level sensor and electronic control, which detects the liquid level 26 and regulates it so that it always remains below the position of the shaft seal 46. The perimeter wall of the pumping chamber 14 is formed in this example by three annular modules 48 stacked on top of each other and sealed together, each housing one of the impellers 18. The suction opening 12 is formed in a separate housing section, which is connected to the rest of the housing by tension bolts 50. In this way, the annular modules can be securely and tightly fastened together. After loosening the traction bolts 50 and removing the independent housing part, the number of annular modules 48 and impellers 18 can be varied as required or according to the available installation height.

Claims (6)

1. CLAIMS 1. Pumping system with a collection tank (22) for liquid and with a liquid pump (10) having a casing (10), forming a suction opening (12), a pumping chamber (14), an outlet pipe (44) and a motor chamber (30), a shaft (16) rotatably mounted in the casing, inside the pumping chamber (14) an impeller (18) is disposed, and in the section located outside the pumped fluid is disposed a rotor (34) of an electric motor (28), which is surrounded by a stator (36) disposed in the motor chamber (30), wherein the liquid pump (10) is mounted in the collection tank (22) such that the shaft (16) extends vertically and the casing (10) is submerged with its suction opening (12) in the liquid, while the motor chamber (30) is above a maximum liquid level (26) of the liquid, characterized by a cooling jacket (40) surrounding the engine chamber, which has a cylindrical shape and an annular chamber (42) and which on one side is in fluid communication with the pumping chamber (14) and on the other side with the outlet pipe (44), in which a pressure pipe (20), which connects the pumping chamber (14) with the cooling jacket (42), opens at a first peripheral position (A) in the cooling jacket (42) and the outlet pipe (44) is connected at a second peripheral position (B) on the cooling jacket (42) and the first and second peripheral positions (A, B) are located diametrically opposite each other. 2. Pumping system according to claim 1, wherein the outlet tube (44) extends radially from the cooling jacket (42). 3. Pumping system according to claim 1 or 2, wherein the outlet tube (44) is arranged on the pumping chamber (14) at the axial end opposite the cooling jacket (42). 4. Pumping system according to one of the preceding claims, wherein parts of the motor chamber (30) protrude axially from the cooling jacket (40) at the end opposite the pumping chamber (14). 5. Pumping system according to one of the preceding claims, wherein a perimeter wall of the pumping chamber (14) is formed by several annular modules (48) detachable from one another and several impellers (18) are attached to the shaft (16) in a detachable manner. 6. Pumping system according to any of the preceding claims, wherein the motor chamber (30) is closed on the side opposite the pumping chamber (14) by means of a shaft joint (46) for the shaft (16) and the shaft (16) is mounted on rolling bearings (29), all of which are located on the side of the shaft joint (46) opposite the pumping chamber.