Pulley-assisted electromagnetic water pump

Abstract

Electrically and mechanically driven motor vehicle attachment (20), comprising: a case (22); a shaft (26) rotatably mounted in the housing (22), wherein the shaft (26) extends along a longitudinal axis (36) between an inlet end (42) and an outlet end (44); an electric motor (24) comprising a stator assembly (58) and a rotor assembly (60) rotatable relative to the stator assembly (58), wherein the electric motor (24) is configured to generate a primary torque flow path when the electric motor (24) is activated; the stator assembly (58) is firmly attached to the housing (22); the rotor assembly (60) is fixedly attached to the shaft (26) so that the rotor assembly (60) rotates with the shaft (26); a pulley (28) rotatably mounted on the input end (42) of the shaft (26) so that the pulley (28) is rotatable relative to the shaft (26) and the rotor assembly (60); and a pulley support mechanism (30) comprising several claw pole structures (110) arranged circumferentially around the rotor assembly (60) and an electromagnet (108) configured to induce a magnetic field between the claw pole structures (110) and the pulley (28) to generate a secondary torque flow path between the pulley (28) and the rotor assembly (60) when the electromagnet (108) is activated.

Description

Technical field

[0001] The present disclosure is directed generally to electrically and mechanically driven automotive add-on components, including, without limitation, electrically and mechanically driven automotive pumps. The subject matter of the disclosure also includes methods for operating the same. For example, DE 103 17 522 A1 describes a compound auxiliary machine for a vehicle for use on a refrigeration circuit device. State of the art

[0002] This section provides background information relating to the present disclosure that does not necessarily represent the prior art.

[0003] Motor vehicles typically include a variety of different automotive components, driven either by electric motors or mechanically by the engine, particularly by a belt driven by the engine's crankshaft. Examples include pumps for circulating coolant, oil, transmission fluid, and fuel. Other examples include pumps for supplying intake air to the engine, sometimes called compressors. Mechanically driven automotive components have several disadvantages, most notably that they cannot be driven when the engine is not running. Furthermore, the rotational speed, and therefore the power output, of mechanically driven automotive components is dependent on the engine speed. Consequently, the rotational speed and power output of typical mechanically driven automotive components cannot be controlled independently of the engine speed.

[0004] Document DE 103 17 522 A1 describes a compound auxiliary machine for a vehicle and a control unit for it, for use in a refrigeration circuit device installed in a vehicle with an idle-stop function that stops the vehicle's engine when the vehicle temporarily stops. Publication DE 10 2004 027 000 A1 discloses a fluid machine, in particular a hybrid compressor for a motor vehicle, whose function is to reduce vibrations and noise from the vehicle.

[0005] Furthermore, DE 11 2012 001 165 T5 is known, which describes control systems for a friction clutch mechanism and a hybrid cooling pump. Friction clutch assemblies are positioned inside the motor housing and feature progressively softer springs that minimize clutch bypass power consumption. The control systems use PWM to control the operation of cylinder coils, which in turn operate the friction clutch assemblies. Disclosure of the invention Technical problem

[0006] Electrically driven automotive components solve the problems associated with typical mechanically driven automotive components, but they also have their own disadvantages. Most electrical systems in motor vehicles generate and operate on 12 volts (V) direct current (DC). The power output of electric motors that can operate on 12 volts (V) DC is limited in practice because the heat generated by the electric motor becomes difficult to manage above a certain power level and can lead to overheating of the electronics. Therefore, it is difficult to provide an electrically driven automotive component with a power output of 1 kilowatt (kW) while simultaneously using a power supply that operates on 12 volts (V) DC.Accordingly, car manufacturers must make do with less powerful electrically operated vehicle add-on parts if they want a vehicle add-on part that can be operated independently of the engine speed and when the engine is not running. Solution to the problem

[0007] This section provides a general summary of the revelation and is not a comprehensive revelation of its full scope or all of its features.

[0008] According to one aspect of the present disclosure, an electrically and mechanically driven automotive accessory is provided. The electrically and mechanically driven automotive accessory comprises a housing, an electric motor configured to drive a shaft in a rotating manner, and a pulley rotatable relative to the electric motor and the shaft. The shaft is rotatably mounted in the housing and extends along a longitudinal axis between an input end and an output end. The electric motor has a stator assembly and a rotor assembly. When the electric motor is activated, it generates a primary torque flow path that drives the rotational motion of the rotor assembly relative to the stator assembly. The stator assembly is fixedly connected to the housing. The rotor assembly is fixedly connected to the shaft, so that the rotor assembly rotates with the shaft.The pulley is rotatably mounted on the input end of the shaft, allowing it to rotate relative to the shaft and rotor assembly. The electrically and mechanically driven automotive component incorporates a pulley support mechanism. This mechanism comprises an electromagnet and multiple claw pole structures arranged circumferentially around the rotor assembly. When the electromagnet is activated, the magnetic field generated by the electromagnet creates a magnetic coupling between the claw pole structures and the pulley. This magnetic coupling establishes a secondary torque flow path between the pulley and the rotor assembly.

[0009] According to another aspect of the present disclosure, a method for operating the electrically and mechanically driven automotive accessory described above is provided. The method comprises the step of applying electricity to electrical windings of the stator assembly to generate an electromagnetic field and a primary torque flow path that rotates the rotor assembly and the shaft. The method also includes the step of rotatingly driving the pulley, which is rotatably mounted on a pulley bearing arrangement. The method continues with the steps of detecting a first rotational speed of the rotor assembly or the shaft and detecting a second rotational speed of the pulley. The method further includes the step of activating the pulley support mechanism when the second rotational speed is greater than the first.The step of activating the pulley support mechanism involves applying electricity to the electromagnet of the pulley support mechanism to induce a magnetic field between the pulley and the claw pole structures on the rotor assembly to create a secondary torque flow path between the pulley and the rotor assembly.

[0010] The secondary torque flow path provided by the pulley support mechanism complements the primary torque flow path generated by the electric motor, allowing the rotor assembly to be driven at a higher speed than would be possible using only the primary torque flow path. As a result, the electrically and mechanically driven automotive accessory described herein can generate 1.7 to 1.8 kilowatts (kW) of pumping power using an electric motor operating on 12 volts (V) direct current (DC). Furthermore, the electrical current supplied to the electrical windings of the stator assembly can be reduced for any given speed when the electromagnet of the pulley support mechanism is activated. This means that higher speeds and power outputs are possible while maintaining an electric motor operating on a 12-volt power supply without overheating.The pulley support mechanism also allows for a reduction in the size of the electric motor, since peak demand usually coincides with high motor speeds, where the speed of the pulley is high and the pulley support mechanism is most effective (i.e., when the pulley support mechanism can provide the greatest increase in speed for the rotor unit).

[0011] Unlike mechanically driven automotive accessories, the electrically and mechanically driven automotive accessory described herein can only be driven by the electric motor when the vehicle's engine is not running. Furthermore, the shaft speed is fully variable and can be controlled independently of the engine speed. The electric current applied to the electromagnet of the pulley support mechanism can be controlled to vary the degree of magnetic coupling between the pulley finger and the rotor assembly. Consequently, the amount of torque transmitted between the pulley finger and the rotor assembly via the secondary torque flow path can be adjusted to control the shaft speed as well as the amount of mechanical resistance the pulley exerts on the vehicle's engine. Brief description of the drawings

[0012] Further advantages of the present disclosure are readily apparent, as they are better understood by reference to the following detailed description in conjunction with the accompanying drawings, wherein: Fig. 1 a perspective side view of an electrically and mechanically driven motor vehicle attachment that was constructed according to the teachings of the present disclosure; Fig. 2 a perspective exploded view of the in Fig. 1 is the electrically and mechanically driven motor vehicle attachment shown; Fig. 3 a side view of the in Fig. 1 is the electrically and mechanically driven motor vehicle attachment shown; Fig. 4 a perspective side view of an exemplary rotor assembly of the in Fig. 1 is the electrically and mechanically driven motor vehicle attachment shown; Fig. 5 another perspective side view of the in Fig. 4 is the rotor assembly shown, with the internal components of the rotor assembly shown in dashed lines; and Fig. 6 a lateral cross-sectional view of the in Fig. 1 is the electrically and mechanically driven vehicle attachment shown. Type of invention

[0013] With reference to the figures, in which the same numbers denote the corresponding parts in the different views, an electrically and mechanically driven motor vehicle attachment 20 is disclosed.

[0014] Exemplary embodiments are provided to ensure that this disclosure is thorough and fully conveys its scope to the person skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, to provide a comprehensive understanding of the embodiments of this disclosure. It will be clear to the person skilled in the art that specific details need not be used, that exemplary embodiments can be embodied in many different forms, and that neither should be interpreted in such a way as to limit the scope of the disclosure. In some exemplary embodiments, known methods, known device structures, and known technologies are not described in detail.

[0015] The terminology used herein serves only to describe specific examples and is not to be understood as limiting. The singular forms "a," "an," and "the" used herein also include the plural forms unless the context clearly indicates otherwise. The terms "exhibit," "exhibiting," "comprising," and "having" are comprehensive and therefore specify the presence of certain features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The procedural steps, processes, and operations described herein are not to be interpreted as necessarily having to be carried out in the order discussed or presented, unless this order is expressly indicated.It should also be understood that additional or alternative steps may be used.

[0016] When an element or layer is described as "on," "interacting with," "connected with," or "coupled with" another element or layer, it may lie directly on top of, interact with, be connected or coupled to, or there may be intervening elements or layers. Conversely, an element described as "directly on," "directly interacting with," "directly connected with," or "directly coupled with" another element or layer may not have any intervening elements or layers. Other words used to describe the relationship between elements should be interpreted similarly (e.g., "between" as opposed to "directly between," "adjacent" as opposed to "directly adjacent," etc.).As used herein, the term “and / or” includes all combinations of one or more of the listed elements.

[0017] Although the terms first, second, third, etc., may be used herein to describe different elements, components, areas, layers, and / or sections, these elements, components, areas, layers, and / or sections should not be restricted by these terms. These terms should only be used to distinguish one element, component, area, layer, or section from another. Terms such as "first," "second," and other numerical terms do not imply any order unless clearly evident from the context.Thus, a first element, a first component, a first area, a first layer or a first section referred to below could also be called a second element, second component, second area, second layer or second section, without this deviating from the teachings of the exemplary embodiments.

[0018] Spatially relative terms such as "inside," "outside," "below," "under," "below," "above," "above," and the like may be used herein to simplify the description and to describe the relationship of one element or feature to another, as illustrated in the figures. Spatially relative terms may refer to different orientations of the device in use or operation, in addition to the orientation shown in the figures. For example, if the device in the figures is inverted, elements described as "below" or "underneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation above and below.The device may be oriented differently (rotated by 90 degrees or in other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0019] With reference to the Fig. 1, Fig. 2 to Fig. 3 The electrically and mechanically driven motor vehicle attachment 20 disclosed herein comprises a housing 22, an electric motor 24 configured to drive a shaft 26 in a rotating manner, and a pulley 28 rotatable relative to the electric motor 24 and the shaft 26. The pulley 28 comprises a belt contact section 28a with a belt contact surface 29 and a secondary torque transmission section 28b. The secondary torque transmission section 28b extends longitudinally from the belt contact section 28a and annularly around at least one section of the electric motor 24. The belt contact section 28a of the pulley 28 is configured to be set in rotation by a belt (not shown), such as a rubber belt, driven by a motor (not shown). The belt contact surface 29 of the pulley 28 engages the belt and may optionally include a grooved channel.The engine can be, without restriction, an internal combustion engine that powers a vehicle (not shown). As explained in more detail below, the electrically and mechanically driven automotive accessory 20 includes a pulley support mechanism 30 that uses electromagnetism to transfer torque from the pulley 28 to parts of the electric motor 24 in order to provide torque assistance (i.e., mechanical thrust) to the electric motor 24 under certain operating conditions.

[0020] Although other configurations are possible, in the illustrated embodiment, the housing 22 comprises a tubular section 32 and a flanged section 34. The tubular section 32 extends annularly around the longitudinal axis 36 between a first housing end 38 and a second housing end 40. The flanged section 34 extends radially outward from the tubular section 32 at the second housing end 40. The shaft 26 of the electrically and mechanically driven automotive accessory 20 is accommodated in the tubular section 32 of the housing 22. The shaft 26 extends along a longitudinal axis 36 between an input end 42 and an output end 44. It should therefore be understood that the term "longitudinal" used herein describes structures that run parallel / coaxially to the longitudinal axis 36.The shaft 26 is longer than the tubular section 32 of the housing 22, such that the inlet end 42 of the shaft 26 extends from the first housing end 38 and the outlet end 44 of the shaft 26 extends from the second housing end 40. The shaft 26 is rotatably mounted in the tubular section 32 of the housing 22 by a shaft bearing assembly 46. Although other configurations are possible, the shaft bearing assembly 46 can comprise an integrated bearing arrangement for the shaft 26 with an outer sleeve 48 pressed into the tubular section 32 of the housing 22 and two longitudinally spaced ball bearing packs 50 arranged radially between the shaft 26 and the outer sleeve 48. During operation, the housing 22 can remain stationary, while the shaft bearing assembly 46 allows the shaft 26 to rotate about its longitudinal axis 36 relative to the housing 22.

[0021] Both the housing 22 and the shaft 26 can be made of a variety of different materials, including various metals. In the illustrated embodiment, the shaft 26 is stepped, with a larger diameter at the inlet end 42 and a smaller diameter at the outlet end 44; however, it should be noted that other configurations are possible, including configurations in which the shaft 26 has a constant diameter over its entire length. Optionally, a shaft seal 52, extending annularly around the shaft 26, can be provided adjacent to the outlet end 44 of the shaft 26. In the illustrated example, the shaft seal 52 is made of an elastic material and is arranged radially between the shaft 26 and the housing 22.In this example, the shaft seal 52 is attached to the housing 22 in such a way that the shaft 26 rotates relative to the shaft seal 52; however, in an alternative embodiment, the shaft seal 52 can be attached to the shaft 26 in such a way that it rotates with the shaft 26 and relative to the stationary housing 22.

[0022] In the illustrated example, the electrically and mechanically driven automotive accessory 20 is a liquid pump, such as a pump for pumping liquids. Such liquids can include, but are not limited to, water, coolant, oil, gear oil, or fuel. According to this embodiment, the electrically and mechanically driven automotive accessory 20 includes an impeller 54 that is fixedly mounted at the output end 44 of the shaft 26. The impeller 54 comprises one or more blades 56. The impeller 54 can be made of a variety of materials, including, without limitation, injection-molded plastic. During operation, the impeller 54 rotates with the shaft 26, causing the blades 56 of the impeller 54 to pump liquid through the liquid pump. However, it should be understood that the scope of this disclosure is not limited to liquid pumps.For example, the electrically and mechanically driven automotive accessory 20 can be configured as an air pump (also known as an air compressor). In other, non-limiting examples, the electrically and mechanically driven automotive accessory 20 could also be another automotive accessory, typically driven by an electric motor 24, an engine accessory belt, the engine's multi-ribbed belt, the engine's crankshaft, or an engine camshaft.

[0023] The electric motor 24 is configured to generate a primary torque flow path that drives the rotation of the shaft 26 when the electric motor 24 is activated. Although other configurations are possible, in the illustrated embodiment, the electric motor 24 comprises a stator assembly 58 and a rotor assembly 60. The stator assembly 58 is fixedly mounted on the tubular section 32 of the housing 22 and therefore remains stationary during operation. The electrically and mechanically driven automotive attachment 20 includes a stationary support element 62, and the stator assembly 58 comprises several stator plates 64, all of which are fixedly mounted on the tubular section 32 of the housing 22. The stator plates 64 are stacked on top of each other and comprise several arms 66 that carry electrical windings 68.Although other configurations are possible, in the illustrated embodiment the stator plates 64 are made of metal and the electrical windings 68 are made of copper wire. Although other configurations are possible, the stator plates 64 and the electrical windings 68 can be coated with a resin or plastic to protect them from corrosion / oxidation, vibration, contamination, and impact damage, and to structurally unify the stator assembly 58.

[0024] The rotor assembly 60 is rotatable about the longitudinal axis 36 relative to the stator assembly 58. The rotor assembly 60 comprises a hub 70, which is fixedly connected to the shaft 26, so that the rotor assembly 60 rotates with the shaft 26. In particular, in the illustrated embodiment, the hub 70 comprises a cylindrical section 72, which is pressed onto the inlet end 42 of the shaft 26. The hub 70 includes a flange 74, which extends radially outward from the cylindrical section 72 to a circumferential edge 76. Accordingly, the hub 70 forms part of an end face 78 of the rotor assembly 60, which faces the pulley 28. The rotor assembly 60 also includes a rotating support element 80. The rotating support element 80 extends longitudinally from the circumferential edge 76 of the hub 70 and circumferentially around at least one section of the stator assembly 58.It should be understood that the words “stationary” and “rotating”, which are used to describe the support elements 62, 80 of the electric motor 24, are used for identification purposes only and refer to the relative movement between these two components when the electric motor 24 is running.

[0025] Permanent magnets 82 are fixed to the rotating support element 80 and are located radially outside the stator plates 64. When electricity (i.e., electric current) is applied to the electrical windings 68 of the stator assembly 58, an electromagnetic field is generated which interacts with the magnetic field of the permanent magnets 82, causing the rotating support element 80 to rotate. The hub 70 and the hub of the rotating support element 80 are integral to each other, forming a single-piece structure, so that when current is applied to the electrical windings 68 of the stator assembly 58, the electric motor 24 drives the shaft 26 in a rotating manner.Although other configurations are possible, the hub 70 and the rotating support element 80 can be made of an iron metal material, and the permanent magnets 82 of the rotor assembly 60 can be made of a ferritic material or rare earth materials, such as samarium cobalt (SmCo) or neodymium iron boron (NdFeB), and can be glued to an inner surface 84 of the rotating support element 80.

[0026] The pulley 28 is rotatably mounted on the input end 42 of the shaft 26, so that the pulley 28 is rotatable relative to the shaft 26 and the rotor assembly 60. In the illustrated example, the belt contact section 28a of the pulley 28 has a hub section 86, a pulley wall 88, and two annular edges 90. The pulley wall 88 extends radially outward from the hub section 86, and the belt contact surface 29 is located between the two annular edges 90. The belt contact surface 29 is configured to mate with (i.e., contact) the belt (not shown), while the two annular edges 90 of the pulley 28 are configured to prevent the belt from slipping / jumping off the pulley 28.The pulley wall 88 comprises an outer surface 92 facing away from the flange 74 of the hub 70 of the rotor assembly 60, and an inner surface 94 facing the flange 74 of the hub 70 of the rotor assembly 60. The pulley 28 is supported by a pulley bearing assembly 96 arranged radially between the cylindrical section 72 of the hub 70 of the rotor assembly 60 and the hub section 86 of the pulley 28. Although other configurations are possible, in the illustrated embodiment, the pulley bearing assembly 96 comprises an inner race 98 pressed onto the cylindrical section 72 of the hub 70 of the rotor assembly 60, an outer race 100 pressed into the hub section 86 of the pulley 28, and several ball bearings 102 arranged radially between the inner and outer races 98, 100.As a result, the pulley 28 can rotate relative to the housing 22 and the stator assembly 58, which remain stationary, and relative to the shaft 26 and the rotor assembly 60, which can rotate independently of the pulley 28.

[0027] With further reference to the Fig. 4 and Fig. The pulley support mechanism 30 comprises an electromagnet 108 mounted on the stationary support element 62 and several claw pole structures 110 arranged circumferentially around the rotating support element 80 of the rotor assembly 60. The claw pole structures 110 are arranged along the rotating support element 80 at circumferentially spaced locations near the circumferential edge 76 of the hub 70. Adjacent claw pole structures 110 reverse polarity between a north pole N and a south pole S (i.e., adjacent claw pole structures 110 have alternating dipoles) when the electromagnet 108 is energized and are separated by magnetic gaps 112 provided in the stationary support element 62 of the rotor assembly 60. It should also be understood that the polarities of the claw pole structures 110 can switch or change each time the electromagnet 108 is deactivated and reactivated.Each of the claw pole structures 110 has a triangular shape with a base 113 and a vertex 114. The tips 116 of adjacent claw pole structures 110 point in opposite longitudinal directions L1 and L2, and the magnetic gaps 112 between the claw pole structures 110 generally have a Z-shaped profile. Several fingers 115 structurally connect the vertices 114 of the claw pole structures 110 to the flange 74 of the hub 70 and the rotating support element 80. The fingers 115 allow the hub 70 and the rotating support element 80 to be manufactured as a single component, thus reducing manufacturing costs. At the same time, the fingers 115 are thin enough to provide a relatively uninterrupted magnetic gap 112 around the claw pole structures 110. To reduce the magnetic losses at the fingers 115, the fingers 115 could alternatively be made of a non-magnetic material, such as aluminum or plastic.

[0028] The secondary torque transmission section 28b of the pulley 28 has a cylindrical shape and extends annularly around the claw pole structures 110, such that the secondary torque transmission section 28b of the pulley 28 is superimposed on the claw pole structures 110 of the rotor assembly 60. The electromagnet 108 is configured to induce a magnetic field between the claw pole structures 110 in the rotating support element 80 and the secondary torque transmission section 28b of the pulley 28. This magnetic field crosses the claw pole structures 110 and jumps to the secondary torque transmission section 28b of the pulley 28 to create a secondary torque flow path between the pulley 28 and the rotor assembly 60 when the electromagnet 108 is activated (i.e., energized). In some configurations, the entire pulley 28 may be made of a magnetic metal.In other configurations, the secondary torque transmission section 28b of the pulley 28 may be made of a magnetic metal material, while the belt contact section 28a of the pulley 28 or sections thereof, such as the hub section 86, the pulley wall 88 and / or the annular edges 90, may be made of other materials, including non-magnetic materials.

[0029] With further reference to Fig. The stationary support element 62 comprises a first wall 116 extending radially between a flanged inner edge 118 and an outer edge 120. The flanged inner edge 118 of the stationary support element 62 is pressed onto the tubular section 32 of the housing 22. The flanged inner edge 118 extends longitudinally from the first wall 116 to a distal end 124 located near the flange 74 of the hub 70 of the rotor assembly 60. Accordingly, the first wall 116 of the stationary support element 62 is perpendicular to the longitudinal axis 36, and the inner flanged edge 118 of the stationary support element 62 is perpendicular to the first wall 116 and parallel / coaxial to the longitudinal axis 36. The stationary support element 62 carries the electromagnet 108 of the pulley support mechanism 30.In the illustrated embodiment, the electromagnet 108 is, for example, a wire coil 126 made of copper wire, which is wound around the flanged inner edge 118, such that the wire coil 126 of the electromagnet 108 is arranged radially between the flanged inner edge 118 of the stationary support element 62 and the rotating support element 80 and longitudinally between the first wall 116 of the stationary support element 62 and the flange 74 of the hub 70 of the rotor assembly 60.

[0030] The stationary support element 62, the rotating support element 80 of the rotor assembly 60, and the hub 70 of the rotor assembly 60 are all made of a magnetic material, for example, a ferrous metal material. As in Fig.As can be best seen in Figure 6, when electricity (i.e., electric current) is applied to the wire coil 126, the electromagnet 108 of the pulley support mechanism 30 induces a magnetic loop 128 in sections of the hub 70 (i.e., in the flange 74), the stationary support element 62 (i.e., in sections of the first wall 116 and the inner flange edge 118), the rotating support element 80 (i.e., in the claw pole structures 110), and the pulley 28 (i.e., in sections of the secondary torque transmission section 28b). When the electromagnet 108 of the pulley support mechanism 30 is deactivated (i.e., de-energized), the magnetic coupling between the pulley 28 and the rotating support element 80 ceases. Consequently, no torque transmission takes place between the pulley 28 and the rotor assembly 60 when the electromagnet 108 is deactivated. However, when the electromagnet 108 of the pulley support mechanism 30 is activated (i.e.(excited) the magnetic field induced between the secondary torque transmission section 28b of the pulley 28 and the claw pole structures 110 of the rotor assembly 60 leads to a torque transmission between the pulley 28 and the rotor assembly 60.

[0031] There are a number of predetermined tolerances (i.e., small gaps) between the outer edge 120 of the stationary support element 62 and the inner surface 84 of the rotating support element 80, and between the distal end 124 of the inner flange edge 118 of the stationary support element 62 and the flange 74 of the hub 70. These tolerances must be small enough to provide a relatively uninterrupted magnetic loop 128 when the electromagnet 108 is activated, but large enough to accommodate manufacturing tolerances and allow relative movement between the rotor assembly 60 and the stator assembly 58, as well as relative movement between the rotor assembly 60 and the pulley 28. As an example, and without limitation, these predetermined tolerances can be 100–200 micrometers (µm), and preferably about 150 micrometers (µm).

[0032] The magnetic coupling between the secondary torque transmission section 28b of the pulley 28 and the rotor assembly 60 requires relative movement between the pulley 28 and the rotor assembly 60. Accordingly, some rotational slip will always be present between the pulley 28 and the rotor assembly 60, even when the electromagnet 108 is activated. The electromagnet 108 of the pulley support mechanism 30 is only activated when the belt drives the pulley 28 at a higher speed than the speed at which the rotor assembly 60 is driven via the primary torque flow path generated by the electric motor 24. When the electromagnet 108 is activated under such conditions, the secondary torque flow path provided by the pulley support mechanism 30 (i.e.,The induced magnetic coupling between the secondary torque transmission section 28b of the pulley 28 and the rotor assembly 60, the primary torque flow path generated by the electric motor 24, allows the rotor assembly 60 to be driven at a higher speed (i.e., higher revolutions per minute / RPM) than would be possible if only the primary torque flow path were used. This increases the fluid flow generated by the impeller 54. Furthermore, the electrical current applied to the electrical windings 68 of the stator assembly 58 can be reduced for any given speed when the electromagnet 108 of the pulley support mechanism 30 is activated.

[0033] In many cases, the pulley support mechanism 30 also allows for a downsizing of the electric motor 24, since the pump's peak demand typically coincides with high motor speeds, at which the speed of the pulley 28 is high and the pulley support mechanism 30 is most effective (i.e., when the pulley support mechanism 30 can provide the greatest increase in the speed of the rotor assembly 60). As explained below, the electromagnet 108 of the pulley support mechanism 30 is deactivated when the primary torque flow path of the electric motor 24 drives the rotor assembly 60 at a speed higher than the speed of the pulley 28. If the electromagnet 108 were not deactivated under such conditions, the pulley support mechanism 30 would slow the rotation of the rotor assembly 60 and act as a brake, which would be undesirable in most applications.

[0034] Unlike mechanically driven automotive attachments, the electrically and mechanically driven automotive attachment 20 described herein can only be driven by the electric motor 24 when the vehicle engine is not running. Furthermore, the rotational speed of the shaft 26 is fully variable and can be controlled independently of the engine speed. The electric current applied to the wire coil 126 of the electromagnet 108 can be controlled to change the degree of magnetic coupling between the secondary torque transmission section 28b of the pulley 28 and the rotor assembly 60. Consequently, the amount of torque transmitted between the secondary torque transmission section 28b of the pulley 28 and the rotor assembly 60 can be adjusted to control the rotational speed of the shaft 26 as well as the amount of mechanical resistance that the pulley 28 exerts on the vehicle engine.In other words, the level of load exerted on the engine by the electrically and mechanically driven motor vehicle attachment 20 can be controlled with regard to engine speed, power output, fuel consumption and / or other operating parameters.

[0035] The electrically and mechanically driven automotive component 20 described above can be controlled according to the method described below. The method includes the step of applying current to the electrical windings 68 of the stator assembly 58 to generate an electromagnetic field and a primary torque flow path that rotates the rotor assembly 60 and thus the shaft 26. The method also includes the step of rotating the pulley 28, which is rotatably mounted on the pulley bearing assembly 96. The method continues with the steps of detecting a first rotational speed of the rotor assembly 60 and / or the shaft 26 and detecting a second rotational speed of the pulley 28.The electrically and mechanically driven automotive accessory 20 can include one or more sensors (not shown) configured to measure / read the first rotational speed of the rotor assembly 60 and / or shaft 26 and the second rotational speed of the pulley 28. The method further includes the step of activating the pulley support mechanism 30 when the second rotational speed (i.e., the rotational speed of the pulley 28) is greater than the first rotational speed (i.e., the rotational speed of the rotor assembly 60 / shaft 26). This step includes applying current to the electromagnet 108 to induce a magnetic field between the pulley 28 and the claw pole structures 110 on the rotor assembly 60, thereby generating a secondary torque flow path between the pulley 28 and the rotor assembly 60.The activation step of the pulley support mechanism 30 generates the magnetic loop 128 described above, which extends around the electromagnet 108 in sections of the stator assembly 58, the rotor assembly 60, and the pulley 28. The procedure can also include the deactivation step of the pulley support mechanism 30 when the first rotational speed (i.e., the rotational speed of the rotor assembly 60 / shaft 26) is greater than the second rotational speed (i.e., the rotational speed of the pulley 28). The activation and deactivation steps of the pulley support mechanism 30 can be performed by a controller (not shown) capable of controlling the output of one or more power supplies (not shown), which may be electrically connected to the wire coil 126 of the electromagnetic and / or electrical windings 68 of the stator assembly 58.

[0036] The foregoing description of the embodiments has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment but, where applicable, are interchangeable and may be used in a selected embodiment, even if these are not specifically shown or described. These and other references should be interpreted as covering any combination in which the inventive novelty is advantageous. Many modifications and variations of the present invention are possible in light of the above teachings and may be carried out differently than specifically described, while remaining within the scope of the appended claims.Furthermore, the steps of the procedure set out herein can be carried out in a different order than that shown herein without this deviating from the scope of the attached claims.

Claims

[1] Electrically and mechanically driven motor vehicle attachment (20), comprising: a case (22); a shaft (26) rotatably mounted in the housing (22), wherein the shaft (26) extends along a longitudinal axis (36) between an inlet end (42) and an outlet end (44); an electric motor (24) comprising a stator assembly (58) and a rotor assembly (60) rotatable relative to the stator assembly (58), wherein the electric motor (24) is configured to generate a primary torque flow path when the electric motor (24) is activated; the stator assembly (58) is firmly attached to the housing (22); the rotor assembly (60) is fixedly attached to the shaft (26) so that the rotor assembly (60) rotates with the shaft (26); a pulley (28) rotatably mounted on the input end (42) of the shaft (26) so that the pulley (28) is rotatable relative to the shaft (26) and the rotor assembly (60); and a pulley support mechanism (30) comprising several claw pole structures (110) arranged circumferentially around the rotor assembly (60) and an electromagnet (108) configured to induce a magnetic field between the claw pole structures (110) and the pulley (28) to generate a secondary torque flow path between the pulley (28) and the rotor assembly (60) when the electromagnet (108) is activated. [2] Electrically and mechanically driven motor vehicle attachment (20) according to claim 1, wherein adjacent claw pole structures (110) change polarities between a north pole and a south pole and are separated by magnetic gaps (112) provided in the rotor assembly (60). [3] .Electrically and mechanically driven motor vehicle attachment (20) according to claim 2, wherein the rotor assembly (60) comprises a hub (70) which is attached to the shaft (26) and extends radially outwards from the shaft to a circumferential edge (76), and a rotating support element (62) which extends longitudinally from the circumferential edge (76) of the hub (70) and circumferentially around at least a section of the stator assembly (58). [4] Electrically and mechanically driven motor vehicle attachment (20) according to claim 3, wherein the claw pole structures (110) are arranged along the rotating support element (80) at circumferentially spaced locations near the circumferential edge (76) of the hub (70). [5] Electrically and mechanically driven motor vehicle attachment (20) according to claim 4, wherein the pulley (28) comprises a belt contact section (28a) with a belt contact surface (29) and a secondary torque transmission section (28b) extending longitudinally from the belt contact section (28a) and annularly around the claw pole structures (110) of the rotor assembly (60). [6] Electrically and mechanically driven motor vehicle attachment (20) according to claim 5, wherein the belt contact section (28a) of the pulley (28) is arranged to be driven by a belt. [7] Electrically and mechanically driven motor vehicle attachment (20) according to claim 5, wherein the secondary torque transmission section (28b) of the pulley (28) has a cylindrical shape and superimposes the claw pole structures (110) of the rotor assembly (60). [8] Electrically and mechanically driven motor vehicle attachment (20) according to claim 4, wherein each of the claw pole structures (110) of the rotor assembly (60) has a triangular shape with a base and a vertex. [9] Electrically and mechanically driven motor vehicle attachment (20) according to claim 8, wherein the vertices (114) of adjacent claw pole structures (110) point in opposite longitudinal directions and wherein the rotor assembly (60) comprises several fingers (115) which structurally connect the vertices (114) of the claw pole structures (110) to the hub (70) and the rotating support element (80). [10] Electrically and mechanically driven motor vehicle attachment (20) according to claim 3, further comprising: a stationary support element (62) which is fixedly attached to the housing (22) and supports the electromagnet (108) of the pulley support mechanism (30). [11] Electrically and mechanically driven motor vehicle attachment (20) according to claim 10, wherein the stationary support element (62) is made of an iron-containing metal material, such that the electromagnet (108) induces a magnetic loop (128) in sections of the hub (70), the stationary support element (62), the rotating support element (80) and the pulley (28). [12] Electrically and mechanically driven motor vehicle attachment (20) according to claim 3, wherein the hub (70) and the rotating support element (80) are integral and form a one-piece structure made of an iron-containing metal material. [13] Electrically and mechanically driven motor vehicle attachment (20) according to claim 3, wherein the rotor assembly (60) comprises permanent magnets (82) which are fixedly attached to the rotating support element (80), and the stator assembly (58) comprises stator plates (64) which are fixedly attached to the housing (22) and carry electrical windings (68). [14] Electrically and mechanically driven motor vehicle attachment (20) according to claim 3, wherein the hub comprises a cylindrical section (72) which receives the input end (42) of the shaft (26), and wherein the pulley (28) is supported by a pulley bearing arrangement which is arranged radially between the cylindrical section of the hub (70) and the pulley (28). [15] Electrically and mechanically driven motor vehicle attachment (20) according to claim 1, wherein the housing (22) comprises a tubular section (32) which accommodates the shaft (26), and wherein the stator assembly (58) is attached to the tubular section (32) of the housing (22). [16] Electrically and mechanically driven motor vehicle attachment (20) according to claim 15, wherein the pulley (28) is supported by a shaft bearing assembly (46) arranged radially between the shaft (26) and the tubular section (32) of the housing (22). [17] Electrically and mechanically driven motor vehicle attachment (20) according to claim 1, further comprising: a paddle wheel (54) which is fixedly attached to the output end (44) of the shaft (26). [18] Electrically and mechanically driven motor vehicle attachment (20) according to claim 1, further comprising: a shaft seal (52) which extends in a ring shape around the shaft (26) and is arranged radially between the shaft (26) and the housing (22). [19] Method for operating an electrically and mechanically driven motor vehicle attachment (20) comprising the steps: Applying electricity to electrical windings (68) of a stator assembly (58) to generate an electromagnetic field and a primary torque flow path that rotates a rotor assembly (60) and a shaft (26) rigidly connected to the rotor assembly (60); rotating drive of a pulley (28) which is rotatably mounted on a pulley bearing arrangement; Detecting a first rotational speed of at least one of the rotor assembly (60) or the shaft (26); Detecting a second speed of the pulley (28); and Activating a pulley support mechanism (30) when the second rotational speed is greater than the first rotational speed, wherein the step of activating the pulley support mechanism (30) includes applying electricity to an electromagnet (108) to induce a magnetic field between the pulley (28) and claw pole structures (110) on the rotor assembly (60) to generate a secondary torque flow path between the pulley (28) and the rotor assembly (60). [20] Method according to claim 19, wherein the step of activating a pulley support mechanism (30) generates a magnetic loop (128) that surrounds the electromagnet (108) in sections of the stator assembly (58), the rotor assembly (60) and the pulley (28).

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