GB2611041A

GB2611041A - Dual-input motor

Info

Publication number: GB2611041A
Application number: GB2113531.4A
Authority: GB
Inventors: Abdul Qayum
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-09-22
Filing date: 2021-09-22
Publication date: 2023-03-29

Abstract

A dual-input motor 200 comprising a rotor (104, Fig 1A) to which is attached a turbine 124, and a stator (102, Fig 1A). The rotor and stator couple magnetically when the stator receives an electric current from an electrical source and the rotor is driven by an electric current, in combination with fluid flow to the turbine. The turbine may comprise fluid diverting element(s) 126 to receive the fluid flow, from fluid source(s) (130, Fig 2), including compressed air, via a nozzle to drive the turbine. The turbine may comprise a Pelton wheel and the fluid diverting elements comprises a plurality of paddles or blades. The magnetic coupling between the rotor and stator may be created by a three-phase supply. The turbine 124 may be coupled to a shaft (134, Figure 2) of the rotor and a controller may control the flow of fluid from a source such as a compressed air source.

Description

Dual-Input Motor The present disclosure relates to a motor, and more particularly to a dual powered motor.

Background

Many governments around the world have set targets reducing the number of vehicles produced using internal combustion engines. As such, electric vehicles utilising electric motors are taking an increasing role in transport in many sectors.

However, electric vehicles suffer from many drawbacks compared with vehicles powered by internal combustion engines. For example, ease of charging, charging times, charging locations, battery lifespan and battery ownership costs.

A possible resistance by mainstream society to adopt plug in electric vehicles is further exacerbated by the lack of available infrastructure to support a transition to all-electric. For example, should 50% (approximately 19.2 million) of the vehicles on the road in the U.K today be replaced by all-electric vehicles and they were to plug in for charging overnight simultaneously, there would be a huge demand on the electricity grid with a heightened risk of failure and blackouts.

Coupled with this, a number of vehicle owners do not have parking available directly outside of or even nearby their residence or place of work and so there are many challenges associated with installing the infrastructure to enable vehicle owners to charge their electric vehicles.

There are further difficulties associated with charging speeds. Faster charging generates copious amounts of heat which possibly leads to reduced battery life and holding charge through degradation. Rapid charging also requires a huge change in infrastructure for it to be efficient in mainstream society, residential electrical installations simply cannot handle the load required for fast charging due to the electrical current needed and the heat generated from passing high amounts of electrical current.

By reducing demand on a battery power source, battery charge and life can be prolonged which would offer more miles per kWh of charge. This would allow for smaller and more lightweight battery packs to be utilised, battery packs which could be easily handled and exchanged.

It is the object of the invention to overcome at least some of the above referenced problems.

Summary

According to the present disclosure there is provided a motor including the features as set out in the claims.

According to a first aspect, there is provided a dual-input motor comprising: a stator; a rotor mounted for rotation relative to the stator; wherein the stator is configured to receive an electric current from an electrical source to generate a magnetic field to magnetically couple the rotor to the stator, in use; a turbine coupled to the rotor for receiving a fluid flow; wherein a combination of electric current and fluid flow is configured to drive the rotor to rotate relative to the stator.

In many motors, the limiting factor for the operation of the motor is the size of the electrical source used to power the motor. The dual input aspect enables the electrical source (e.g. a battery) to last for longer as less current is required to drive the motor at the same speed. In other words, the presence of the turbine receiving fluid-slow to also drive the rotor means that less current is required from the electrical source. This dual -input motor is particularly beneficial to those applications in which there are size/capacity limits on battery size, such as in electric vehicles. The use of this dual-input motor enables battery size and weight to be significantly reduced or alternatively for the battery to last for longer. The dual-input motor may be a dual-input induction motor.

The turbine may comprise one or more fluid diverting elements configured to receive the fluid flow to drive the turbine.

In one example, the motor includes one or more fluid sources configured to provide the fluid flow to the turbine. In other words, the motor may include a plurality of fluid sources to provide fluid flow to the turbine.

The fluid source may be in the form of a compressed air source. That is to say that compressed air may be used to drive the turbine. The compressed air may be configured to pass through a fluid-injection nozzle configured to deliver the compressed air to the one or more fluid diverting elements of the turbine. The fluid-injection nozzle may be an air-injection nozzle. The advantages of compressed air when considered for use on a motor vehicle as an energy source are its low weight, ease of storage and easily renewable nature.

In one example, the motor includes a controller configured to control the delivery of compressed air through the nozzle of the fluid source.

The turbine may comprise a Pelton wheel and the fluid diverting elements comprises a plurality of paddles In one example the one or more fluid diverting elements comprise a plurality of blades configured to deflect on-coming air.

In one example, the motor comprises an induction motor.

In one example, the electrical source is configured to provide a three-phase electrical current to generate a rotating magnetic field in the stator.

In one example, the stator comprises three electromagnets configured to receive the electric current from the electrical source; and the rotor comprises a plurality of electromagnets configured to be coupled with the electromagnets on the stator.

The motor may comprise an axial flux motor. The motor may comprise a radial flux motor In one example, the turbine is coupled to a shaft of the rotor.

According to one example, there is provided a method of driving a dual-input motor according to any one of the preceding claims, comprising: receiving an electric current, at the stator, from an electrical source to generate a magnetic field to magnetically couple the rotor to the stator; receiving a fluid flow to rotate the turbine, wherein a combination of the electric current and fluid flow drives the rotor to rotate relative to the stator.

Brief Description of the Drawings

Examples of the present disclosure will now be described with reference to the accompanying drawings.

Figure 1A shows a schematic example of an electric motor; Figure 1B shows a schematic example of a cross-section of a stator; Figure 10 shows a schematic example of an induction rotor; Figure 1D shows a schematic example of a cross-section through both the stator and the rotor; Figure 2 shows a schematic example of a turbine; Figure 3 shows an image of a turbine coupled to a rotor shaft to form a dual input motor; Figure 4 shows a schematic view of a dual input motor; and Figure 5 shows a flow-chart of method steps for driving a motor

Detailed Description

The present disclosure relates to a dual-input motor. The motor receives two, distinct, types of energy input to power the motor. One of the inputs is an electric current from a battery and a second input is a fluid configured to power a turbine of the motor. The combination of inputs works synergistically to reduce the current drawn from the battery, thereby extending the lifetime of the battery.

Figure 1A shows an example of an electric motor 100. The electric motor 100 is used to convert electric current into mechanical work. In the example shown in Figure 1A, the electric motor 100 takes the form of a three-phase induction motor, but other types of motors, such as a single phase induction motor are envisaged. In one example, the electric motor may take the form of an axial flux induction motor, which provides a compact size and high power density. Alternatively, the motor may take the form of a radial flux induction motor.

The motor 100 includes two main parts, the stator 102 and the rotor 104. The stator 102 of the motor 100 may include three main parts -the stator frame 106, stator core 108 and stator winding (not shown). As suggested, the stator frame 106 provides a frame or support to the stator core 108 and the stator winding. The stator core 108 carries the alternating magnetic flux, in use. The stator core 108 may comprise a plurality of slots 112 that receive a stator winding.

The stator winding may receive a three-phase electric current provided by a power supply 110. The number of poles of the motor 100 depends on the internal connection of the stator winding and it will govern the speed of the motor. The number of poles may have an inverse relationship relative to the speed of the motor. In other words, the greater the number of poles, the less speed the motor will have. The stator winding may be connected in star or delta arrangement by the connection of terminals a terminal box. An end terminal of each stator winding may be connected to the terminal box. Hence, there may be six terminals (two of each phase) in the terminal box.

Figure 1B shows a cross-section of a stator core 108. The plurality of slots 112 are shown arranged around the periphery of the stator core 108. In Figure 1B, the stator windings are not shown within the slots for clarity.

The rotor 104 is a rotating part of the motor 100. In one example, the rotor 104 takes the form of a squirrel cage rotor. In another example, the rotor takes the form of a wound rotor (or slip ring rotor) depending on the type of motor 100. In the example of a squirrel cage induction motor, the rotor comprises a cylindrical laminated core and has slots on an outer periphery. The slots may not be parallel but rather skewed at an angle. This arrangement helps to prevent magnetic locking between the stator 102 and rotor 104. It results in a smoother operation and reduces the noise of the motor 100.

The squirrel cage rotor consists of rotor bars instead of the rotor winding. The rotor bars are made up of aluminium, brass, or copper. Rotor bars are permanently shorted by end rings. So, it makes a complete close path in the rotor circuit. The rotor bars are welded or braced with the end rings to provide mechanical support. In this type of rotor, slip rings and brushes are not used. Hence, the construction of this type of motor is simpler and more robust.

An alternative to the squirrel cage induction motor is a slip-ring or wound induction motor. Figure 1C shows an example of a wound induction rotor 104. The rotor 104 may include a laminated cylindrical core 118. One or more slots 120 may be provided on an outer periphery of the core 118. The rotor winding (not shown in Figure 1C) may be located inside these slots 120.

In this type of rotor 104, the rotor winding is wound in such a way that the number of poles matches the number of poles of the stator winding. The rotor winding can be connected as a star or delta. End terminals of rotor windings may be connected to slip-rings. So, this motor 100 is known as a slip-ring induction motor.

Figure 10 also shows an opening 122 in the core 118 of the rotor through which a shaft (not shown) extends. In one example, the shaft is part of the rotor itself. In other examples, the rotor is coupled with the rotor shaft.

Figure 1D shows a cross-section through both the stator 102 and the rotor 104. In this example, the rotor 104 is at least partially housed within the stator 102. An air gap 114 is shown between the stator 102 and the rotor 104.

Adjacent stator windings (not shown) may be offset at an electrical angle of 120° relative to each other. When a three-phase supply is given to the stator winding, a rotating magnetic field (RMF) is induced in the stator 102. The rotating magnetic field rotates at a synchronous speed The speed of the rotating magnetic field is known as synchronous speed (NS).

According to Faraday's law, the rotating magnetic field induced by the stator 102 cuts across the rotor bar or the rotor winding in the rotor 104. This induces an electromagnetic force (e.m.f) in the rotor 104. The rotor circuit is a closed path so, due to this EMF current will flow through the rotor circuit.

The current-carrying conductor in the rotor 104 induces a magnetic field. So, the rotor 104 current induces a second magnetic field. Due to the interaction between the stator flux and rotor flux, the rotor 104 will rotate. Here, the rotor current is produced due to inductance. Therefore, this motor is known as the induction motor. In other words, the current supplied to the stator results in a magnetic coupling between the rotor and the stator.

In this example, the speed of the rotor 104 is less than the speed of synchronous speed (i.e. the speed of the rotating magnetic field). The rotor 104 tries to catch the rotating magnetic field of the stator 102, but the speed of the rotor 104 is less than the speed of synchronous speed.

The synchronous speed depends on the number of poles and supply frequency. The difference between the actual speed of the rotor and synchronous speed is known as slip.

Figure 2 shows an example of a turbine 124. In one example the turbine 124 may comprise a PeIton wheel. In this example, the turbine 124 includes one or more vanes 126 configured to receive a fluid. The vanes 126 may be coupled with a runner 128. The vanes 126 are configured to receive a fluid-flow from one or more fluid sources 130. In this example, a compressed air source is used as a fluid source 130. The fluid is ejected through a nozzle of the fluid source 130 and directed to the vane 126. The fluid 132 is shown schematically in Figure 2. The fluid will cause the turbine 124 to rotate such that the fluid ejected through the nozzle will then impinge upon different vanes 126 as the turbine 124 rotates. The turbine 124 may be coupled to a shaft 134 that extends through the rotor 104. The shaft 134 may be considered to be a part of the rotor 104, or alternatively be considered to be a separate element that is coupled to the rotor 104.

Alternatively, the turbine 124 may be coupled with another rotating part of the rotor 104.

In examples, the turbine 124 may take the form of crossflow, Francis or Turgo turbines.

In one example, each fluid source 130 comprises one or more solenoids to control valves through which the fluid is ejected from the fluid source 130. The one or more solenoids may be controlled via a fluid source controller. That is to say that the fluid ejected through from the fluid source 130 may be controlled by the fluid source controller.

In one example, the electric supply 110 may take the form of a first power pack or battery to provide a source of electric current to the motor 100 and a second power pack or battery to provide polarity to magnetise the rotor of the motor 100. The second

B

power pack or battery may be used when permanent magnets are not placed on the rotor itself. If permanent magnets are present, then a second power pack or battery may not be necessary.

The combination of the motor 100 as described above with the turbine 124 is known as a dual-input motor 200.

The addition of a turbine 124 as an additional energy input to the dual-input motor 200 means that the current drawn from an electrical power source 110 may be reduced. In other words, the rotor 104 is driven by a combination of fuel sources, one electrical and one fluid based.

An example of a dual input motor 200 in which the turbine 124 is coupled to the rotor 104 is shown in Figure 3. In this example, the turbine 124 is connected to a shaft 134 of the rotor 104.

In the example of the dual input motor 200, the rotating magnetic field induced by the stator 102 cuts across the rotor bar or the rotor winding in the rotor 104 to induce an electromagnetic force in the rotor 104. As described above, the rotor circuit is a closed path so, due to this EMF current will flow through the rotor circuit. The current-carrying conductor in the rotor 104 induces a magnetic field. So, the rotor current induces a second magnetic field (rotor flux). Due to the interaction between the stator flux and rotor flux, the rotor 104 will rotate. However, in this example, the rotor 104 will also receive an energy input from the fluid flow on the turbine 124 too. The additional rotational force provided by the turbine 124 acts as a secondary energy source to drive the rotor 104. The difference between the synchronous speed and the operating speed (known as slip) is significantly reduced, thus optimising the efficiency of the dual-input motor 200. This has the effect of reducing the amount of electric current drawn from the electric supply 110.

In this example, the speed of the rotor 104 may still be less than the speed of synchronous speed (i.e. the speed of the rotating magnetic field). The dual input motor 200 is configured to enable the electric power source to last for longer, as less current is being drawn to run the motor 200 as some energy to run the motor is being provided by the fluid source.

In one example, oncoming air may be used as the fluid source to drive the turbine. For example, the dual input motor 200 may include one or more flow diverters that are configured to divert the oncoming air such that it drives the turbine 124.

Example 1

A test was conducted on a three-phase dual-input motor 200 comprising a turbine 124 in the form of a PeIton wheel coupled to the rotor 104.

The motor 200 is powered by 36V battery. An additional 6V battery was used to provide polarity to magnetise the stator of the dual-input motor 200. An air controller is used to control the supply of a compressed air to drive the PeIton wheel. The PeIton wheel comprises eleven vanes 126 spaced around a runner 128. The compressed air was stored at a pressure of approximately 72PSI (0.5MPa). In this example a 'A inch (0.64cm) nozzle and a 1-inch (2.54cm) nozzle were used at two locations around the PeIton wheel to drive the PeIton wheel.

In this example, the dual-input motor 200 was run initially based on the electric source only (i.e. with the fluid supply in the form of compressed air switched off). The rotor 104 20 operated at 1965RPM and the peak current demand drawn from the electric power source was 9.4Amps.

With fluid assistance (i.e. when the compressed air was switched on), the rotor operated at 2018 RPM and the peak current demand from the electric power source was 8.2 Amps. In other words, with the assistance of the compressed air, the dual input motor reduces the current drawn from the electric power source. Therefore, the dual-input motor 200 is configured to enable the electric power source to last for longer, as less current is being drawn to run the dual-input motor 200 as some energy to run the motor is being provided by the fluid source.

A highly schematic example of the dual input motor 200 is shown in Figure 4. In this example, the turbine 124 is coupled to a shaft 134 of the rotor (or a shaft that extends through the rotor 104).

Figure 5 shows an example of a flow diagram for method steps of driving a dual-input motor 200. At step 302, the method includes receiving an electric current, at the stator, from the electrical source to generate a magnetic field to magnetically couple the rotor 104 to the stator 102. At step 304, the method includes receiving a fluid flow to rotate the turbine 124. A combination of the electric current and fluid flow drives the rotor to rotate relative to the stator.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS: 1. A dual-input motor comprising: a stator; a rotor mounted for rotation relative to the stator; wherein the stator is configured to receive an electric current from an electrical source to generate a magnetic field to magnetically couple the rotor to the stator, in use; a turbine coupled to the rotor for receiving a fluid flow; wherein a combination of electric current and fluid flow is configured to drive the rotor to rotate relative to the stator.
2. The dual-input motor according to claim 1, wherein the turbine comprises one or more fluid diverting elements configured to receive the fluid flow to drive the turbine.
3. The dual-input motor according to claim 2, comprising one or more fluid sources configured to provide the fluid flow to the turbine.
4. The dual-input motor according to any one of claims 2 to 3, comprising a fluid-injection nozzle configured to deliver the fluid to the one or more fluid diverting elements.
5. The dual-input motor according to claim 4, comprising a controller configured to control the delivery of fluid through the nozzle of the fluid source.
6. The dual-input motor according to any one of claims 3 to 5, wherein the one or more fluid sources comprises a compressed air source.
7. The dual-input motor according to any one of the preceding claims, wherein the turbine comprises a PeIton wheel and the fluid diverting elements comprises a plurality of paddles.
8. The dual-input motor according to claim 2, wherein the one or more fluid diverting elements comprise a plurality of blades configured to deflect on-coming air.
9. The dual-input motor according to any one of the preceding claims, wherein the electrical source is configured to provide a three-phase electrical current to generate a rotating magnetic field in the stator.
10. The dual-input motor according to any one of the preceding claims, wherein the stator comprises three electromagnets configured to receive the electric current from the electrical source; and the rotor comprises a plurality of electromagnets configured to be coupled with the electromagnets on the stator.
11. The dual-input motor according to any one of claims 1 to 8, wherein the motor comprises an axial flux motor.
12. The dual-input motor according to any one of claims 1 to 8, wherein the motor comprises a radial flux motor.
13. The dual-input motor according to any one of the preceding claims, wherein the turbine is coupled to a shaft of the rotor.
14. A method of driving the dual-input motor according to any one of the preceding claims, comprising: receiving an electric current, at the stator, from the electrical source to generate a magnetic field to magnetically couple the rotor to the stator; receiving a fluid flow to rotate the turbine, wherein a combination of the electric current and fluid flow drives the rotor to rotate relative to the stator.