Electric fluid pump with a heating element

Abstract

The present invention relates to an electric fluid pump (100a, 100b, 100c) comprising a housing (111), an electric motor (10), a pump unit (50), and a control unit (30). The housing (111) has at least one suction port (70) and at least one pressure port (90). The electric motor (10) has a stator (12) and a rotor (14) that can rotate about an axis of rotation (X). The pump unit (50), which is connected to the rotor (14), has a suction inlet (72) connected to the suction port (70) and a pressure outlet (92) connected to the pressure port (90). The control unit (30) drives the electric motor (10). The electric fluid pump (100a, 100b, 100c) further comprises a heating element (20, 21), at least a portion of which is arranged in the suction port (70) and electrically connected to the control unit (30). Figure 1

Description

Title of the invention: Electric fluid pump equipped with a heating element

[0001] The present invention relates to an electric fluid pump, in particular an electric fluid pump with a heating element more particularly suitable for automotive applications.

[0002] In general, the automotive drivetrain has various components that require lubrication. These components are normally lubricated using a lubricating fluid. The lubricating fluid is circulated within the drivetrain using a fluid pump.

[0003] Generally, in a colder environment, the temperature of the lubricating fluid decreases. This leads to an increase in the viscosity of the lubricating fluid in the vehicle's drivetrain, which impairs the fluid's fluidity. This results in the fluid solidifying, causing the fluid pump impeller to stall. This makes it difficult for the electrically driven fluid pump to operate. Normally, the efficiency of an electrically driven fluid pump in an automobile is not considered in relation to the temperature of the fluid that must be circulated within the drivetrain.

[0004] It is therefore necessary to solve the technical problem associated with the assembly explained above.

[0005] Therefore, one object of the present arrangement is to provide an assembly which overcomes the aforementioned disadvantages and other disadvantages of known arrangements and to provide an electric fluid pump with improved efficiency in maintaining oil temperature.

[0006] The present arrangement relates to an electric fluid pump comprising a housing having at least one suction port and at least one pressure port, an electric motor having a stator and a rotor capable of rotating about an axis of rotation, a pump unit which is driven by the rotor and having a suction inlet in fluidic connection with the suction port and a pressure outlet in fluidic connection with the pressure port, a control unit for driving the electric motor, and the electric fluid pump comprising a heating element. According to the invention, at least a portion of the heating element is arranged in the suction port and is electrically connected to the control unit. Consequently, because the heating element is arranged in the suction port, the viscosity of the fluid can be reduced before entering the suction inlet.Consequently, the efficiency of the motor-driven fluid pump. The electric pump's performance in colder environments can be improved. The fact that the heating element is connected to the pump's electronic components means the electric fluid pump is much more compact and easier to integrate into the vehicle.

[0007] According to one aspect of the arrangement, at least one suction orifice extends along an axis and the heating element is arranged substantially coaxially to this axis.

[0008] According to another aspect of the arrangement, the heating element is a resistive element.

[0009] According to another aspect of the arrangement, the heating element is a thermistor, including an element with a positive temperature coefficient.

[0010] According to another aspect of the arrangement, the heating element is a coating, an ink, a flexible film, a metal wire or a coil.

[0011] According to another aspect of the arrangement, the heating element is positioned over at least 20% of the length of at least one suction port along the axis. Consequently, the contact area of ​​the heating element with the fluid can be improved.

[0012] According to another aspect of the arrangement, an electrical line extends through the electric fluid pump in order to electrically connect the control unit and the heating element.

[0013] According to another aspect of the arrangement, the pump unit is a gerotor, a gear, a vane or a centrifugal.

[0014] According to another aspect of the arrangement, the fluid is oil for the lubrication of a vehicle transmission system.

[0015] According to another aspect of the arrangement, the housing is thermally insulated. The oil should be kept hot inside the electric fluid pump. This means that when the outside temperature is, for example, -30 °C, the oil is heated at the inlet, flows into the internal volume of the pump, and exits. Throughout this movement inside the pump, the housing should thermally insulate the oil in the electric fluid pump from the external temperature. Alternatively, an insulating layer can be added around the housing.

[0016] The present arrangement can be better understood with reference to the following description and drawings. The components in the figures are not necessarily to scale, the emphasis being rather on illustrating the principles of the arrangement. Furthermore, in the figures, identical reference numbers designate corresponding parts. In the drawings:

[0017] [Fig.1] illustrates a cross-section of an electric fluid pump equipped with a heating element, configured according to the present invention;

[0018] [Fig.2] illustrates a cross-section of a second embodiment of an electric fluid pump equipped with a heating element, configured according to the present invention;

[0019] [Fig.3] illustrates a cross-section of a third embodiment of an electric fluid pump equipped with a heating element, configured according to the present invention.

[0020] In the following description, reference is made to accompanying drawings, which form part thereof, and in which specific embodiments in which the invention can be applied are illustrated. These embodiments are described in sufficient detail to enable a person skilled in the art to carry out the invention, and it will be understood that the embodiments can be combined or that other embodiments can be used and that structural and logical modifications can be made without departing from the scope of the present invention. The following detailed description should therefore not be interpreted as limiting, and the scope of the present invention is defined by the accompanying claims and their equivalents.

[0021] The present description refers to [Fig.1], [Fig.2] and [Fig.3] which are described in a common way for reasons of conciseness.

[0022] The electric fluid pump 100a, 100b, 100c, equipped with a heating element 20, configured according to the present invention, comprises a housing 111 on which an electric motor 10, a pump unit 50, and a control unit 30 are mounted. The electric fluid pump circulates a fluid in an automotive transmission.

[0023] In a non-limiting example, the housing is formed as a dedicated housing 111 formed as a single piece. In another example, which is not shown, the housing 111 can be formed as a separate housing for the electric motor 10, the pump unit 50, and the control unit 30.

[0024] The housing 111, which is mainly an injection-molded component, consists substantially of three parts, namely, from left to right, the control unit part 113, the electric motor part 101, the pump unit part 115.

[0025] The housing 111 extends substantially transversely to an axis of rotation X, forming an external cover on a first side 11 to form a first separating wall 13 receiving the control unit 30. Between the first side 11 and the first separating wall 13 forms the control unit portion 113. The housing 111 extends substantially transversely to an axis of rotation X, forming an external cover on a second side 17 configured with at least one suction port 70 and at least one pressure port 90. The housing 111 extends substantially transversely to an axis of rotation X to form a second separating wall 15 receiving the pump unit 50. Between the second side 17 and the second separating wall forms the pump unit portion 115. The electric motor 10 is disposed between the pump unit 50 and the control unit 30, delimited by the first separating wall 13 and the second separating wall 15.

[0026] The electric motor 10 is implemented as an internal rotor motor and comprises a stator 12 and a rotor 14. The rotor 14 is received inside the stator 12, leaving an annular space that facilitates the rotation of the rotor 13 around the axis of rotation X. The rotor 14 is mounted on a rotor shaft 16. The pump unit 50 comprises an impeller 52. The pump unit 50 is in a drive connection with the rotor 14. The drive connection implies that the rotor 14 of the electric motor 10 and the impeller 52 of the pump unit 50 are coaxially aligned and that the impeller 52 is mounted on the rotor shaft 16 of the electric motor 10. The electric motor 10 drives the impeller 52 of the pump unit 50.

[0027] The pump unit 50 further comprises a suction inlet 72 and a pressure outlet 92. The suction inlet 72 is in fluidic connection with the suction port 70 and the pressure outlet 92 is in fluidic connection with the pressure port 90. The rotation of the impeller 52 of the pump unit 50 creates a vacuum near the suction inlet 72 which draws the fluid beyond the suction port 70. The introduced fluid is pressurized near the pressure outlet 92 in the pump unit 50 and pumped through the pressure port 90 out of it.

[0028] The control unit 30 is used to drive the electric motor 10 and to provide instructions to the heating element 20. An electrical line 25 is provided to transmit the instruction from the control unit 30 to the heating element 20, 21. The electrical line 25 is integrated into the housing 111, preferably within the peripheral walls. The control unit 30 includes an electrical connection (not shown) for controlling and distributing the required electrical power to the electric motor 10 and the heating element 20, 21. At least a portion of the heating element 20, 21 is arranged in the suction port 70 and is electrically connected to the control unit 30.

[0029] Preferably, the suction orifice 70 extends along an axis XI and the heating element 20 is arranged substantially coaxially with this axis XL. The axis XI is parallel to the axis X. By way of exception, the heating element 20, 21 is arranged along at least 20% of the length of at least one suction orifice 70 along the axis XL.

[0030] The suction port 70, which extends axially from the housing 111, is arranged with respect to the axis XI and is positioned radially outwards at a distance from the axis of rotation X on the second side 17 of the housing. The heating element 20, 21 is located on the inner wall of the suction port 70. The control unit 30 sets an operating time for the heating element 20, 21. Thus, the heating element 20, 21 can be heated well before the rotation of the electric fluid pump 100a, 100b, 100c, which then heats the fluid to lower its viscosity.

[0031] A temperature sensor (not shown) is in contact with the fluid, for example at the suction port 70, and detects the fluid temperature. Based on the feedback from the temperature sensor, the control unit 30 activates the heating element 20, 21, which heats the fluid adjacent to it. As a result, the fluid temperature increases in the suction port 70 and in the suction inlet 72 adjacent to the impeller 52.

[0032] Generally, the control unit 30 is configured to turn on the heating element 20, 21 before the vehicle engine starts.

[0033] The control unit 30 can be configured to activate the heating element 20, 21 based on an input from the vehicle's cabin heating system. The vehicle cabin is heated by the cabin heating system before the vehicle starts, according to the user's preferences. From this input, the control unit 30 is informed that the ambient temperature is low and begins to activate the heating element 20, 21 to increase the fluid temperature.

[0034] The control unit 30 can also be configured to power up the heating element 20, 21 based on the input from the opening of the vehicle by the driver.

[0035] In one embodiment, the heating element 20, 21 is a resistive element. In another embodiment, the heating element 20, 21 is a thermistor, preferably a positive temperature coefficient element made of solid-state ceramic chips that acts as a means of protection against overheating.

[0036] In one example, the positive temperature coefficient element has a first side and a second side. The first side is arranged in a complementary manner to the inner side of the suction orifice 70 and the second side is submerged by / in contact with the fluid for heating the fluid.

[0037] In a first embodiment shown in [Fig. 1], the heating element 20 is, for example, a coating or an ink. The periphery / inner wall of the suction orifice 70 is appropriately adapted to have the ink or coating of the heating element 20 imprinted on it.

[0038] As a variant of this first embodiment, the heating element 20 is a flexible film. The flexible film may be a strip-type heating element having a heating side and a fastening side. The fastening side is attached to the inner periphery of the suction orifice 70 and the heating side is in contact with the fluid.

[0039] In other embodiments shown in [Fig. 2] and [Fig. 3], the heating element 21 is a metal wire. Without limitation, the metal wire is arranged in the form of a spiral or a coil having at least one turn. An axis of the coil is arranged substantially coaxially with the axis XI of the orifice 70 suction power.

[0040] In the embodiment shown in [Fig. 3], the heating element 21 is partially extended inside the suction inlet 72 adjacent to the impeller. The suction inlet 72 is designed to receive the heating element 21 extended adjacent to the impeller 52. The heating element 21 is arranged in the suction orifice 70 and the suction inlet 72 such that the heating element 21 is completely surrounded by the fluid. The fluid is heated by the heating element 21 and is thus brought to a desired temperature. This can be achieved uniformly and with relatively little energy input in a short period of time due to the arrangement of the heating element 21 along the length of the suction orifice 70.

[0041] As illustrated in [Fig.1], [Fig.2] and [Fig.3], an electrical line 25 extends through the electric fluid pump 100a, 100b, 100c in order to electrically connect the control unit 30 and the heating element 20, 21.

[0042] In one example, the impeller 52 of the pump unit 50 is, for example, a gerotor. In another example, the impeller 52 of the pump unit 50 may be a gear pump, a vane pump, or a centrifugal pump.

[0043] In all embodiments, the fluid is a lubricating oil. The electric fluid pump 100a, 100b, 100c circulates the lubricating oil for the lubrication of a vehicle transmission system.

Claims

Demands

1. An electric fluid pump (100a, 100b, 100c) comprising a housing (111) having at least one suction port (70) and at least one pressure port (90), an electric motor (10) having a stator (12) and a rotor (14) capable of rotating about an axis of rotation (X), a pump unit (50) which is in a drive connection with the rotor (14) and having a suction inlet (72) in fluidic connection with the suction port (70) and a pressure outlet (92) in fluidic connection with the pressure port (90), a control unit (30) for driving the electric motor (10), the electric fluid pump (100a, 100b, 100c) comprising a heating element (20, 21), characterized in that at least a portion of the heating element (20) is arranged in the suction port (70) and is electrically connected to the control unit (30).

2. Electric fluid pump according to claim 1, characterized in that at least one suction port (70) extends along an axis (XI) and the heating element (20, 21) is arranged substantially coaxially to this axis (XI).

3. Electric fluid pump according to claim 1, characterized in that the heating element (20, 21) is a resistive element.

4. Electric fluid pump according to claim 3, characterized in that the heating element (20, 21) is a thermistor, in particular an element with a positive temperature coefficient.

5. Electric fluid pump according to claim 3 or 4, characterized in that the heating element (20, 21) is a coating, an ink, a flexible film, a metal wire or a coil.

6. Electric fluid pump according to any one of the preceding claims, characterized in that the heating element (20, 21) is arranged over at least 20% of the length of at least one suction port (70) along the axis (XI).

7. Electric fluid pump according to any one of the preceding claims, characterized in that an electric line (25) extends through the electric fluid pump (100a, 100b, 100c) in order to electrically connect the control unit (30) and the heating element (20, 21).

8. Electric fluid pump according to any one of the preceding claims, characterized in that the pump unit (50) is a gerotor, a gear, a vane or a centrifugal.

9. Electric fluid pump according to any one of the preceding claims, characterized in that the fluid is oil for the lubrication of a vehicle transmission system.

10. Electric fluid pump according to any one of the preceding claims, characterized in that the casing (111) is thermally insulated.

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