阅读说明：本技术 一种电机转子护套、转子结构及包括其的电机 (Motor rotor sheath, rotor structure and motor comprising same ) 是由 熊博文 张芳 龚高 彭利明 江耀星 于 2021-07-26 设计创作，主要内容包括：本发明提供一种电机转子护套、转子结构及包括其的电机。电机转子护套包括：护套壳体,为筒状结构；第一伸缩部,为筒状结构,沿护套壳体筒状结构轴向可伸缩地设置在护套壳体内；第二伸缩部,为筒状结构,沿护套壳体轴向可伸缩地设置在护套壳体内；驱动器,设置在第一伸缩部和第二伸缩部之间,且两端分别与第一伸缩部和第二伸缩部相连；驱动器在电机低速时,使电机转子护套具有第一伸缩部与第二伸缩部收缩且相互靠近的第一工作状态；在电机高速时,使电机转子护套具有第一伸缩部与第二伸缩部伸出且相互远离的第二工作状态。本发明电机转子护套能够根据转子的转速自动调整工作状态,从而可以提升转子强度,使转子适应更高转速。(The invention provides a motor rotor sheath, a rotor structure and a motor comprising the same. The electric motor rotor sheath includes: the sheath shell is of a cylindrical structure; the first telescopic part is of a cylindrical structure and is arranged in the sheath shell in a telescopic manner along the axial direction of the cylindrical structure of the sheath shell; the second telescopic part is of a cylindrical structure and is arranged in the sheath shell in a telescopic manner along the axial direction of the sheath shell; the driver is arranged between the first telescopic part and the second telescopic part, and two ends of the driver are respectively connected with the first telescopic part and the second telescopic part; when the motor is in a low speed state, the driver enables the motor rotor sheath to have a first working state that the first telescopic part and the second telescopic part are contracted and close to each other; when the motor is in a high speed state, the motor rotor sheath is in a second working state that the first telescopic part and the second telescopic part extend out and are far away from each other. The motor rotor sheath can automatically adjust the working state according to the rotating speed of the rotor, thereby improving the strength of the rotor and enabling the rotor to adapt to higher rotating speed.)

1. An electric machine rotor sheath, comprising:

the sheath shell is of a cylindrical structure;

the first telescopic part is of a cylindrical structure and is arranged in the sheath shell in a telescopic manner along the axial direction of the cylindrical structure of the sheath shell;

the second telescopic part is of a cylindrical structure and is arranged in the sheath shell in a telescopic manner along the axial direction of the sheath shell;

the driver is arranged between the first telescopic part and the second telescopic part, and two ends of the driver are respectively connected with the first telescopic part and the second telescopic part;

when the motor is in a low speed state, the driver enables the motor rotor sheath to have a first working state that the first telescopic part and the second telescopic part are contracted and close to each other; when the motor is in a high speed state, the motor rotor sheath is in a second working state that the first telescopic part and the second telescopic part extend out and are far away from each other.

2. The electric machine rotor sheath of claim 1, wherein the drive comprises:

the first propeller is connected with the first telescopic part and used for controlling the first telescopic part to stretch; the second propeller is connected with the second telescopic part and used for controlling the second telescopic part to stretch;

a charge and discharge circuit for charging and discharging the first propeller and the second propeller;

when the motor is in a low speed state, the charging and discharging circuit is charged, and when the motor is in a high speed state, the charging and discharging circuit discharges electricity, so that the first propeller and the second propeller act to drive the first telescopic part and the second telescopic part to extend out.

3. The electric machine rotor sheath of claim 2, wherein the charge and discharge circuit is a bi-directional half-bridge dc converter circuit.

4. The electric machine rotor sheath of claim 3, wherein the charge and discharge circuit comprises: the circuit is composed of an inductor L, a first diode D1, a second diode D2, a first charging capacitor C1 and a second charging capacitor C2, wherein two diodes (D1 and D2) are arranged behind the inductor L, the second diode D2 and the inductor L form a loop, and the first diode D1 and the second charging capacitor C2 form a loop.

5. The electric machine rotor sheath of any one of claims 2-4, further comprising a speed sensor for detecting a rotational speed of the electric machine rotor sheath,

the speed sensor is arranged in the sheath shell and connected with the charge-discharge circuit, and the charge-discharge circuit controls the first propeller and the second propeller according to the rotating speed of the motor rotor.

6. A rotor structure, comprising:

a first stub shaft having one end formed with a first end connection section;

a second stub shaft having a second end connection section formed at one end thereof;

the electric machine rotor sheath of any one of claims 1-5, the first telescoping portion being connected to the first end connection segment and the second telescoping portion being connected to the second end connection segment.

7. The rotor structure of claim 6, further comprising magnetic steel disposed within the motor rotor sheath between the first stub shaft and the second stub shaft.

8. The rotor structure of claim 6, wherein the first telescoping portion is an interference fit with the first end connection section,

the second telescopic part is in interference fit with the second end connecting section.

9. The rotor structure of claim 6, wherein the first expansion portion has a coefficient of thermal expansion that is less than a coefficient of thermal expansion of the first end connection segment,

the thermal expansion coefficient of the second expansion part is smaller than that of the second end connecting end.

10. An electrical machine comprising a rotor structure according to any one of claims 6-9.

11. The electric machine of claim 10 wherein the machine rotor sheath is in a first operating state when the rotor structure is at a low rotational speed and in a second operating state when the rotor structure is at a high rotational speed.

Technical Field

The invention relates to the technical field of motors, in particular to a motor rotor sheath, a motor rotor structure and a motor comprising the motor rotor sheath.

Background

The high-speed permanent magnet synchronous motor has the advantages of high power density, good dynamic response, simple structure and the like, and becomes one of the research hotspots in the international electrotechnical field. In the existing high-speed rotor design, a layer of thin protective sleeve is generally used, but once the interference between the protective sleeve and a short shaft after machining is finished is determined, the protective sleeve cannot be changed, the rotor shaft cannot be optimally protected at low rotating speed and high rotating speed, and the cost performance of the protective sleeve is greatly reduced due to the allowance left in the design.

Disclosure of Invention

In view of this, the present invention provides a rotor sheath for a motor, a rotor structure and a motor including the same, which are at least used for solving the technical problem that the rotor sheath in the prior art cannot provide a better protection effect at different rotation speeds, specifically:

in a first aspect, the present invention provides a rotor sheath for an electrical machine, comprising:

the sheath shell is of a cylindrical structure;

the first telescopic part is of a cylindrical structure and is arranged in the sheath shell in a telescopic manner along the axial direction of the cylindrical structure of the sheath shell;

the second telescopic part is of a cylindrical structure and is arranged in the sheath shell in a telescopic manner along the axial direction of the sheath shell;

the driver is arranged between the first telescopic part and the second telescopic part, and two ends of the driver are respectively connected with the first telescopic part and the second telescopic part;

when the motor is in a high speed state, the driver enables the motor rotor sheath to have a first working state that the first telescopic part and the second telescopic part extend out and are far away from each other; when the motor is in a low speed state, the motor rotor sheath is enabled to have a second working state that the first telescopic part and the second telescopic part are contracted and are close to each other.

Further optionally, the driver comprises:

the first propeller is connected with the first telescopic part and used for controlling the first telescopic part to stretch; the second propeller is connected with the second telescopic part and used for controlling the second telescopic part to stretch;

a charge and discharge circuit for charging and discharging the first propeller and the second propeller;

when the motor is in a low speed state, the charging and discharging circuit is charged, and when the motor is in a high speed state, the charging and discharging circuit discharges electricity, so that the first propeller and the second propeller act to drive the first telescopic part and the second telescopic part to extend out.

Further optionally, the charging and discharging circuit is a bidirectional half-bridge dc conversion circuit.

Further optionally, the charging and discharging circuit includes: the circuit is composed of an inductor L, a first diode D1, a second diode D2, a first charging capacitor C1 and a second charging capacitor C2, wherein two diodes (D1 and D2) are arranged behind the inductor L, the second diode D2 and the inductor L form a loop, and the first diode D1 and the second charging capacitor C2 form a loop.

Further optionally, the motor rotor sheath further comprises a speed sensor for detecting the rotation speed of the motor rotor sheath,

the speed sensor is arranged in the sheath shell and connected with the charge-discharge circuit, and the charge-discharge circuit controls the first propeller and the second propeller according to the rotating speed of the motor rotor.

In a second aspect, the present invention provides a rotor structure comprising:

a first stub shaft having one end formed with a first end connection section;

a second stub shaft having a second end connection section formed at one end thereof;

in the motor rotor sheath, the first telescopic part is connected with the first end connecting section, and the second telescopic part is connected with the second end connecting section.

Further optionally, the rotor structure further includes magnetic steel, and the magnetic steel is disposed in the motor rotor sheath and located between the first stub shaft and the second stub shaft.

Further optionally, the first telescoping portion is in interference fit with the first end connection section,

the second telescopic part is in interference fit with the second end connecting section.

Further optionally, the first expansion and contraction portion has a coefficient of thermal expansion less than a coefficient of thermal expansion of the first end connection segment,

the thermal expansion coefficient of the second expansion part is smaller than that of the second end connecting end.

In a third aspect, the present invention provides an electric machine comprising the above rotor structure.

Further optionally, when the rotor structure is at a low rotation speed, the motor rotor sheath is in a first working state, and when the rotor structure is at a high rotation speed, the motor rotor sheath is in a second working state.

According to the invention, the first telescopic part and the second telescopic part which can be telescopic relative to the protective sleeve shell are arranged, so that the motor rotor sheath has a first working state in which the first telescopic part and the second telescopic part are close to each other and a second working state in which the first telescopic part and the second telescopic part are far away from each other, and the motor rotor sheath can automatically adjust the working state according to the rotating speed of the rotor, thereby improving the strength of the rotor and enabling the rotor to adapt to higher rotating speed.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings. The drawings described below are merely some embodiments of the present disclosure, and other drawings may be derived from those drawings by those of ordinary skill in the art without inventive effort.

Fig. 1 shows a schematic structural diagram of a rotor sheath of a motor according to an embodiment of the invention (a first working state);

FIG. 2 is a schematic structural diagram of a rotor sheath of a motor according to an embodiment of the invention (second operating state);

FIG. 3 shows a charge and discharge circuit diagram of an embodiment of the invention;

FIG. 4 is a schematic view of a rotor structure according to an embodiment of the present invention (with a rotor sheath of a motor in a first operating state);

fig. 5 shows a rotor structure diagram (the motor rotor sheath is in a second working state) of the embodiment of the invention.

In the figure:

1. a first minor axis; 11. a first end connection section; 2. a second minor axis; 21. a second end connection section; 3. a motor rotor sheath; 31. a first telescopic part; 32. a sheath housing; 33. a second telescopic part; 4. magnetic steel; 51. a first propeller; 52. a second propeller; 61. a first speed sensor; 62. a second speed sensor.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and "a" and "an" generally include at least two, but do not exclude at least one, unless the context clearly dictates otherwise.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.

According to the invention, the first telescopic part and the second telescopic part which can be telescopic relative to the protective sleeve shell are arranged, so that the motor rotor sheath has a first working state in which the first telescopic part and the second telescopic part are close to each other and a second working state in which the first telescopic part and the second telescopic part are far away from each other, and the motor rotor sheath can automatically adjust the working state according to the rotating speed of the rotor, thereby improving the strength of the rotor and enabling the rotor to adapt to higher rotating speed. The invention is described in detail below with reference to specific examples:

as shown in fig. 1 to 5, the present invention provides a rotor sheath 3 of an electric machine, as shown in fig. 1 and 2, including:

a sheath housing 32 having a cylindrical structure;

a first telescopic portion 31 having a cylindrical structure and slidably provided inside the sheath housing 32 in an axial direction of the sheath housing 32;

a second telescopic portion 33 having a cylindrical structure and slidably provided inside the sheath housing 32 in the axial direction of the sheath housing 32;

an actuator disposed between the first telescopic part 31 and the second telescopic part 33 and connected to the first telescopic part 31 and the second telescopic part 33, the actuator being configured to drive the first telescopic part 31 and the second telescopic part 33 to move along the axial direction of the sheath housing 32,

the motor rotor protective sleeve 3 has a first working state that the first telescopic part 31 and the second telescopic part 33 are close to each other and a second working state that the first telescopic part 31 and the second telescopic part 33 are far away from each other, and the working state of the motor rotor protective sleeve can be automatically adjusted according to the rotating speed.

Preferably, the driver includes: a first propeller 51 connected to the first telescopic part 31 for controlling the movement of the first telescopic part 31; a second propeller 52 connected to the second telescopic part 33 for controlling the second telescopic part 33 to move; a charge and discharge circuit for supplying power to the first thruster 51 and the second thruster 52. Further, the motor rotor sheath 3 is made of alloy materials, and what needs to be described is that: the first and second impellers 51, 52 are micro speed drives, preferably micro drives having a length and width dimension not exceeding 10mm, and the shape may be determined according to the sheath structure.

Preferably, as shown in fig. 3, the charging and discharging circuit is a bidirectional half-bridge dc conversion circuit, and is composed of an inductor L, a first diode D1, a second diode D2, a first charging capacitor C1, and a second charging capacitor C2, and two diodes (D1, D2) are disposed behind the inductor L, wherein the second diode D2 and the inductor L form a loop, and the first diode D1 and the second charging capacitor C2 form a loop, so that the inductor can be fully charged and discharged by turning off the diodes, the power loss of the components is low, and the switching rate is fast. The charge and discharge circuit can charge at a low rotation speed, and make the motor rotor sheath 3 in a first working state, and discharge at a high rotation speed, so that the driver acts to push the first telescopic part 31 and the second telescopic part 33 to extend out of the sheath shell 32.

Specifically, the working process of the charge and discharge circuit of the driver is as follows:

when the rotor is in a high rotating speed, the bidirectional half-bridge converter works in a boosting mode, the switch tube S1 is always turned off, the switch tube S2 works in a PWM control mode, at the moment, the inductor discharges electricity, and the micro driver acts to stretch and retract the sheath. So when one power switch tube works, the other power switch tube is turned off.

When the rotor is in low rotation speed, the circuit works in a voltage reduction mode (as shown in fig. 5), at the moment, the eddy current on the rotor side carries out voltage reduction charging on the power supply through the converter, and at the moment, the telescopic sheath is static. I.e., S1 remains off, S2 is controlled by PWM. When S2 is switched on, the power supply charges the inductor L, the inductor L starts to store energy, and the inductor voltage Ui is UL;

when the rotor is at high speed, S2 is turned off, and the power supply and inductor L supply power to the microdriver through the freewheeling first diode D1, and also charge the second charging capacitor C2, at which time the current decreases linearly as the inductor releases power from the easily available Uo ═ Ui + UL. At this time, the micro-driver outputs force to drive the sheath to stretch and contract, and the magnitude of the output section voltage Uo is determined by the PWM duty ratio of the control switch tube S2.

Considering the switching loss, heat dissipation, noise reduction of the switching tube IGBT and the allowable switching frequency of the general IGBT, f is 20 KHZ.

Among these, the bidirectional half-bridge dc converter has several distinct advantages: the voltage and current stress of the switch tube IGBT and the diode is relatively small; only one relatively small inductor is used in the circuit for energy transfer; the conduction loss of the components is small, and the energy conversion efficiency is high.

Further, those of ordinary skill in the art will appreciate that the drawings provided herein are for illustrative purposes and are not necessarily drawn to scale.

The motor rotor sheath 3 further comprises a speed sensor for detecting the rotating speed of the motor rotor sheath 3, the speed sensor is arranged in the sheath shell 32 and is connected with the charging and discharging circuit, and the charging and discharging circuit controls the first propeller 51 and the second propeller 52 according to the rotating speed of the motor rotor. Preferably, the speed sensors comprise a first speed sensor 61 connected to the first impeller 51 and a second speed sensor 62 connected to the second impeller 52, respectively, in coordination with the control of the two impellers.

As shown in fig. 4 and 5, the present invention also provides a rotor structure, including:

a first stub shaft 1, one end of the first stub shaft 1 being formed with a first end connection section 11;

a second short shaft 2, wherein the second short shaft 2 is coaxially arranged with the first short shaft 1, and a second end connecting section 21 is formed at one end of the second short shaft 2;

the motor rotor sheath 3 is of a cylindrical structure and has elasticity along the axial direction of the motor rotor sheath 3, wherein one end of the motor rotor sheath 3 is sleeved on the first end connecting section 11; the other end of the motor rotor sheath 3 is sleeved on the second end connecting section 21;

the magnetic steel 4 is arranged in the motor rotor sheath 3, and the magnetic steel 4 is positioned between the first end connecting section 11 and the second end connecting section 21;

rotor structure is through improving rotor connected mode, utilize 3 covers of telescopic electric motor rotor sheath to establish two minor axises, but based on the telescopic part of electric motor rotor sheath 3 (first pars contractilis 31 and second pars contractilis 33 promptly) adopt the coefficient of thermal expansion to be far less than the material of minor axis, rotate the in-process at a high speed at the rotor and utilize 3 extensions of driver driving motor rotor sheath that inlay in electric motor rotor sheath 3 inside to hold the minor axis tightly, thereby effectively promote rotor suspension precision, guarantee the motor steady operation under high rotational speed.

In some optional manners, an end of the first end connecting section 11 close to the magnetic steel 4 is sleeved with the motor rotor sheath 3, and a diameter of a portion of the first end connecting section 11 not sleeved with the motor rotor sheath 3 is larger than a diameter of a portion of the first end connecting section 11 sleeved with the alloy sheath. And/or one end of the second end connecting section 21 close to the magnetic steel 4 is sleeved with the motor rotor sheath 3, and the diameter of the part of the second end connecting section 21 not sleeved with the motor rotor sheath 3 is larger than the diameter of the part of the second end connecting section 21 sleeved with the alloy sheath. Based on set up the reducing structure on the minor axis, also can carry on spacingly to the specific degree of depth that 3 covers of electric motor rotor sheath were established, prevent that electric motor rotor sheath 3 from excessively nesting on the minor axis and causing the unable condition such as withdraw of 3 parts of electric motor rotor sheath, also can avoid electric motor rotor sheath 3 excessively to extend and influence other structures.

Preferably, when the first telescopic part 31 is in a contracted state, the first telescopic part 31 is matched with the first end connecting section 11 to form a first annular heat dissipation groove, and the first annular heat dissipation groove is used for dissipating heat of the rotor structure; and/or when the second telescopic part 33 is in a contracted state, the second telescopic part 33 is matched with the second end connecting section 21 to form a second annular heat dissipation groove, and the second annular heat dissipation groove is used for dissipating heat of the rotor structure. In the embodiment, as the magnetic steel 4 is arranged between the two short shafts, the micro driver is embedded in the motor rotor sheath 3, and the first short shaft 1, the second short shaft 2, the magnetic steel 4 and the outer telescopic motor rotor sheath 3 are in interference fit, the motor rotor sheath 3 does not change axially (shrink state) when the motor rotor rotates at a low speed, and an annular heat dissipation groove (concave step) is formed to effectively increase the heat dissipation area; when the rotating speed is high, the driver pushes the rotor 3 sheath, the motor rotor sheath 3 stretches, the short shaft is effectively covered, and the rotor strength is enhanced. In the present embodiment, when the rotor speed is higher than 50000R/min, it is determined as high speed, and conversely, it is determined as low speed.

In this embodiment, the first expansion part 31 of the motor rotor sheath 3 is in interference fit with the first end connecting section 11, and preferably, the thermal expansion coefficient of the first expansion part 31 is selected to be smaller than that of the first end connecting section 11 when the material is selected. Optionally, the thermal expansion coefficient proportional relation satisfies: the coefficient of thermal expansion of the first telescopic part 31 is less than one tenth of the coefficient of thermal expansion of the first end connecting section 11.

Meanwhile, when the rotor sheath is matched with the second end connecting section 21, the second expansion part 33 can be in interference fit with the second end connecting section 21, and the thermal expansion coefficient of the second expansion part 33 is smaller than that of the second end connecting section 21. Optionally, the thermal expansion coefficient proportional relation satisfies: the second expansion part 33 has a thermal expansion coefficient smaller than one tenth of that of the second end connection section 21.

In the embodiment, optimization of material selection of the telescopic sheath is combined, the strength of the rotor can be effectively enhanced at a high rotating speed, all parts of the rotor are ensured to be in a tightly-held state, the suspension precision is improved, and stable operation of the motor is ensured; at low rotation speed, the rotor loss is reduced, the heat dissipation area is increased, and the temperature rise at the rotor side is effectively reduced; and when the rotor is in a full-speed section, the efficient and stable operation of the motor can be ensured.

In some alternatives, the driver includes: at least one first impeller 51 arranged inside the rotor sheath and located close to the outer end side of the first end connection section 11; and/or at least one second impeller 52 arranged inside the rotor sheath and located close to the outer end side of the second end connection section 21.

Preferably, the drive comprises a plurality of first impellers 51, the plurality of first impellers 51 being evenly distributed around the inner circumferential wall of the rotor sheath. The drive includes a plurality of second impellers 52, the plurality of second impellers 52 being evenly distributed about the inner circumferential wall of the rotor sheath.

It should be noted that: the rotor rotates at high speed to generate eddy current in the sheath, so that the micro driver is supplied with electric energy, when the driver detects a given rotating speed (high rotating speed), the telescopic part of the sheath is driven to further effectively cover the short shaft, and the thermal expansion coefficient of the telescopic sheath material is far smaller than that of the short shaft. Therefore, under the action of temperature, the sheath can tightly hold the short shaft,

in this embodiment there is provided an electric machine, preferably a permanent magnet machine, comprising the above-described rotor structure.

The rotor structure comprises two short shafts, magnetic steel 4 and a motor rotor protective sleeve. The magnetic steel 4 is arranged between the two short shafts, the micro driver is embedded in the rotor sheath, and the telescopic part of the rotor sheath is made of a material with a thermal expansion coefficient far smaller than that of the short shafts; the two short shafts, the magnetic steel 4 and the telescopic rotor sheath at the outer side are in interference fit.

When the rotor is in low rotational speed, motor rotor sheath 3 produces the vortex, and this part eddy current is absorbed by charge-discharge circuit, and the driver charges this moment, and motor rotor sheath 3 is in initial condition, and 3 axial effective length of motor rotor sheath diminish this moment, and the vortex loss reduces, and the rotor side calorific capacity reduces, and the recess that forms between motor rotor sheath 3 that does not stretch out and draw back and minor axis has increased cooling area, does benefit to the cooling of rotor side, and the motor performance rises.

When the rotor is at a high rotating speed, the driver discharges electricity to push the first telescopic part 31 and the second telescopic part 33 to move and extend out of the sheath shell 32, so that the rotor shaft is effectively covered, and the first telescopic part 31 and the second telescopic part 33 are in a holding state with the short shaft due to the fact that the thermal expansion coefficient is far smaller than that of the short shaft, so that stable operation of the rotor at a high speed is effectively guaranteed.

When the rotating speed of the motor is reduced to a low rotating speed, the micro driver is charged again, the telescopic part sheath and the short shaft are not held tightly along with the reduction of the loss of the rotor side and the reduction of the temperature under the low frequency, and the micro driver pushes the sheath back to the initial state. Along with the contraction of the length of the alloy sheath, the eddy current loss is reduced, and the performance of the motor is effectively improved.

Exemplary embodiments of the present disclosure are specifically illustrated and described above. It is to be understood that the present disclosure is not limited to the precise arrangements, instrumentalities, or instrumentalities described herein; on the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.