HYBRID HYSTERESIS MOTOR
20170310199 · 2017-10-26
Inventors
Cpc classification
H02K19/106
ELECTRICITY
H02K19/08
ELECTRICITY
H02K1/146
ELECTRICITY
International classification
H02K19/08
ELECTRICITY
Abstract
A hybrid hysteresis motor is disclosed. The hybrid hysteresis motor includes a stator with, a plurality of axial slots on a first base-end and a plurality of radial slots on an inner surface. The motor further includes an output shaft, a first axial-flux rotor mounted on the output shaft and associated with the stator, and a radial-flux rotor mounted on the output shaft and disposed inside the stator.
Claims
1. A hybrid hysteresis motor comprising: a stator including a first base-end, an inner surface, a plurality of first axial slots disposed along the first base-end, and a plurality of radial slots disposed along the inner surface; an output shaft; a first axial-flux rotor associated with the stator, wherein the first axial-flux rotor is mounted on the output shaft with an axial air gap extending between the first axial-flux rotor and the first base-end of the stator; and a radial-flux rotor associated with the stator, wherein: the radial-flux rotor is mounted on the output shaft and is disposed inside the stator with a radial air gap extending between the radial-flux rotor and the stator, and the first axial slots and the radial slots of the stator host a stator winding.
2. The hybrid hysteresis motor according to claim 1, wherein the stator further includes a second base-end, and a plurality of second axial slots disposed along the second base-end.
3. The hybrid hysteresis motor according to claim 2, further comprising a second axial-flux rotor associated with the stator, wherein the second axial-flux rotor is mounted on the output shaft with an axial air gap extending between the second axial-flux rotor and the second base-end of the stator.
4. The hybrid hysteresis motor according to claim 1, wherein the stator comprises a soft magnetic composite material.
5. The hybrid hysteresis motor according to claim 1, wherein the stator comprises Mn—Zn ferrite material.
6. The hybrid hysteresis motor according to claim 1, wherein the plurality of first axial slots includes 24 to 36 axial slots.
7. The hybrid hysteresis motor according to claim 1, wherein the plurality of radial slots includes 24 to 36 radial slots.
8. A reverse hybrid hysteresis motor comprising: a stator including a first base-end, an outer surface, a plurality of axial slots disposed along on the first base-end, and a plurality of radial slots disposed along the outer surface; an output shaft; a first axial-flux rotor associated with the stator, wherein the first axial-flux rotor is mounted on the output shaft with an axial air gap extending between the first axial-flux rotor and the first base-end of the stator; and a radial-flux rotor associated with the stator, wherein: the radial-flux rotor is mounted on the output shaft and is disposed outside the stator, and a radial air gap extends between the radial-flux rotor and the stator; and the axial slots and the radial slots of the stator host a stator winding.
9. The reverse hybrid hysteresis motor according to claim 8, wherein the stator further comprises a second base-end, and a plurality of second axial slots disposed along the second base-end.
10. The reverse hybrid hysteresis motor according to claim 9, further comprising a second axial-flux rotor associated with the stator, wherein the second axial-flux rotor is mounted on the output shaft with an axial air gap extending between the second axial-flux rotor and the second base-end of the stator.
11. The reverse hybrid hysteresis motor according to claim 8, wherein the stator comprises a soft magnetic composite material.
12. The reverse hybrid hysteresis motor according to claim 8, wherein the stator comprises Mn—Zn ferrite material.
13. The reverse hybrid hysteresis motor according to claim 8, wherein the plurality of first axial slots includes 24 to 36 axial slots.
14. The reverse hybrid hysteresis motor according to claim 8, wherein the plurality of radial slots includes 24 to 36 radial slots.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The drawing figures depict one or more implementations in accord with the present teachings, by way of example only, not by way of limitation. In the figures, like reference numerals refer to the same or similar elements.
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DETAILED DESCRIPTION
[0031] In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.
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[0034] The present disclosure is directed to a hybrid hysteresis motor with a stator design that is capable of ferrying flux lines in both radial and axial directions. Benefits from this feature include, but are not limited to, the ability to combine axial-flux and radial-flux rotors in a hysteresis motor, thereby providing the advantages of both axial-flux hysteresis motors and radial-flux hysteresis motors in a single structure. As mentioned hereinabove in connection with
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[0036] In different implementations, the stator 201 may be made of a solid or substantially solid magnetic material associated with isotropic ferromagnetic behavior and homogeneous magnetic characteristics in both the axial and radial directions. The magnetic material allows the stator 201 to ferry the flux lines in both radial and axial directions. In some implementations, the solid magnetic material may be selected from soft magnetic composites (SMCs) or a soft ferrite.
[0037] For purposes of this disclosure, an SMC may be understood to refer to materials including ferromagnetic powder particles that are surrounded by an electrical insulating film. An SMC offers several advantages over traditional laminated steel cores in most applications. For example, SMC includes advantages such as three-dimensional (3D) isotropic ferromagnetic behavior, very low eddy current loss, relatively low total core loss at medium and high frequencies, a prospect of greatly reduced weight, and other such advantages. According to some implementations, the solid magnetic material may include Somaloy 130i-SGTechnologies or other grades of solid magnetic materials.
[0038] As noted above, in other implementations, the magnetic material can include a soft ferrite. For purposes of this disclosure, a soft ferrite refers to a kind of ceramic compound composed of iron oxide (Fe.sub.2O.sub.3) that is chemically combined with one or more additional metallic oxides such as MnO or other metallic oxides. Soft ferrites are ferromagnetic, which means that soft ferrites may be magnetized or attracted to a magnet, while being electrically nonconductive, which results in a low core loss at high frequencies.
[0039] Referring again to
[0040] In the implementation of
[0041] In some implementations where the stator core is made of a soft ferrite, in view of the relatively small electrical conductivity of the ferrite core, the use of an insulator sleeve in the radial and axial slots before assembling the winding may not unnecessary. However, in some other implementations, in order to help prevent damage in the winding process, a thin layer of an industrial insulator may be disposed on the stator core before winding. The core loss is smaller in the hybrid hysteresis motor due to this negligible ferrite core electrical conductivity. The soft ferrite materials such as Mn—Zn type materials that may be used in the stator of the hybrid hysteresis motor show comparatively low losses at high frequencies in comparison with silicon steels. Hence, the core losses will be much smaller in the hybrid hysteresis motor.
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[0043] The hybrid hysteresis motor 216 further includes a combination rotor including a first axial-flux rotor 223, a second axial-flux rotor 224, and a radial-flux rotor 225 that are each mounted on an output shaft and are rotatable therewith. A general direction of flux lines is shown in
[0044]
EXAMPLE 1
[0045] In this example a hybrid hysteresis motor is described, consistent with an implementation of the present disclosure. The design parameters of the hybrid hysteresis motor of EXAMPLE 1 are set forth in Table 1 below. In this example, the stator core is made of Mn—Zn ferrite and the rotors are made of Nickel alloy steel.
TABLE-US-00001 TABLE 1 Design Parameters of an example hybrid hysteresis motor Parameter Designated by Value Unit Outer radius of stator R.sub.os 60 Mm Outer radius of disk R.sub.od 60 Mm Inner radius of core axial part R.sub.ia 40 Mm Outer radius of ring R.sub.or 24 Mm Total axial length l.sub.a 40 Mm Slot opening B 5 Mm Axial slot height h.sub.as 12 Mm Height of radial slot h.sub.rs 28 Mm Thickness of ring t.sub.r 2 Mm Thickness of disk t.sub.d 3 Mm Number of poles P 2 Number of phases M 3 Radial air gap length g.sub.r 2 Mm Axial air gap length g.sub.a 2 Mm Total ampere-turn per pole per NI 200 phase Number of slot conductors N.sub.sl 50 Number of slots n.sub.s 24 Conductor diameter d.sub.con 0.5 mm
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EXAMPLE 2
[0053] In EXAMPLE 2 a test set-up was utilized for testing the hybrid hysteresis motor as described in detail in connection with EXAMPLE 1. In EXAMPLE 2, a sensitive dynamometer that includes an eddy-current coupler, a precise and adjustable PID controller, and a real time data acquisition system was used for testing the performance of the hybrid hysteresis motor. A highly accurate coupling connects the output shaft of the hybrid hysteresis motor to the dynamometer. All input and output parameters of the hybrid hysteresis motor are controlled by the controller and saved in the data acquisition system.
[0054] All tests were performed near the synchronous speed, as the magnetic operating point of a hysteresis motor at the synchronous speed is unstable with a small variation of the input voltage. The starting torque (asynchronous mode) in the hysteresis motors is greater than the synchronous torque due to the eddy-current component of the torque. Thus, in order to measure the output torque and other output parameters of the hybrid hysteresis motor, a multistage test is defined and was implemented in this example.
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[0056] Before initiating the test and saving the data into the data acquisition system, some preparatory measures were performed to ensure that the motor and the bearings attained a stable temperature during a predetermined time period. During this period, the hybrid hysteresis motor operated in the synchronous mode, corresponding to an initial condition of the hybrid hysteresis motor state. This condition is identified as a first state 705 in the graphs shown in
[0057] Once the testing began, the PID controller of the dynamometer configured to control the load torque of the eddy-current coupler was utilized to limit the motor speed to a predefined value near the synchronous speed (2900 rpm). This state is identified as a second state 706 in the graphs of
[0058] The input voltage was then increased and set to a point corresponding to the saturation current of the hysteresis material. This state is identified as a third state 707 in the graphs of
[0059] In order to measure the output parameters and evaluate the motor performance, the input voltage was reduced step by step, as illustrated in first graph 701. The reduction in voltage led to a decrease in the motor speed at each step, as seen in second graph 702. During the voltage reduction steps, the motor works toward overcoming the load torque (by inherent self-starting characteristics) and reaches the target speed of 2900 rpm. The reduction in the input voltage continues until the machine cannot overcome the load torque and reaches the 2900 rpm speed. This state is labeled as a fourth state 708 in the graphs of
EXAMPLE 3
[0060] In this example, three hysteresis motors were tested: (1) the hybrid hysteresis motor as described in detail in connection with EXAMPLE 1, which is hereinafter referred to as “HARFHM”; (2) a hybrid hysteresis motor without the radial-flux rotor, which operates like an axial-flux hysteresis motor and is hereinafter referred to as “AFHM”; and (3) a hybrid hysteresis motor without the axial-flux rotor, which operates like a radial-flux hysteresis motor and is hereinafter referred to as “RFHM”. The test setup as described above with reference to EXAMPLE 2 was used to perform the testing.
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[0062] ”; the measured data for AFHM are designated by symbol “
”; and the measured data for RFHM are designated by symbol “
”.
[0063] Referring to first graph 901 of
[0064] The hybrid hysteresis motor consistent with implementations of the present disclosure is avoids the poor performance characteristics of conventional hysteresis motors, and provides improved output torque and efficiency. The hybrid hysteresis motor may incorporate the advantageous features of both the conventional axial-flux and radial-flux hysteresis motors by providing the features of both rotors in a single, stable structure. The hybrid hysteresis motor may be suitable for industrial applications, especially where an inherent self-starting characteristic is required.
[0065] While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed, herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.
[0066] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.
[0067] The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.
[0068] Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.
[0069] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0070] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various implementations. This is for purposes of streamlining the disclosure, and is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
[0071] While various implementations have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more implementations and implementations are possible that are within the scope of the implementations. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any implementation may be used in combination with or substituted for any other feature or element in any other implementation unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the implementations are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.