CN1004112B - Electromachine using iron band, which combined both electric and magnetic effect (two-layer windinghead) - Google Patents
Electromachine using iron band, which combined both electric and magnetic effect (two-layer windinghead) Download PDFInfo
- Publication number
- CN1004112B CN1004112B CN86100239.3A CN86100239A CN1004112B CN 1004112 B CN1004112 B CN 1004112B CN 86100239 A CN86100239 A CN 86100239A CN 1004112 B CN1004112 B CN 1004112B
- Authority
- CN
- China
- Prior art keywords
- winding
- stator
- rotor
- motor
- band steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Images
Landscapes
- Iron Core Of Rotating Electric Machines (AREA)
- Windings For Motors And Generators (AREA)
Abstract
The present invention discloses an electromagnetic integrative electric machine made of strip steel, which comprises a motor and a generator. The electric machine has the key point that a stator of the electric machine (if the electric machine is a motor, the electric machine comprises a rotor) is cast by a pure electrician iron sheet with insulation lacquer; the stator is not only a conductive winding of the electric machine but also a magnetic conductive iron core of the electric machine. Compared with the traditional motors, the present invention has the characteristics of small volume, large capacity, high efficiency, strong short-time overload capability, prolonged service life, etc., and also eliminates the defects of additional moment, noise, Carter 's coefficients of air gaps, especially a series of defects of stray copper iron loss, etc. which are formed because of tooth harmonics in the traditional motors. The present invention does not consume copper materials.
Description
The invention belongs to machine field.
Conventional motors is from the existing till now last 100 years history of invention, before invention is made, no matter be motor or generator, its common feature is that conductive winding and conducting magnet core adhere to two bodies separately, the result is that circle must be slotted to place winding in the stator, and end winding also invalid (can not participate in acting) part causes whole stator inner headed face long-pending (comprising the end winding length) can be used to produce the part of effective air gap magnetic field (participating in acting), generally is no more than 1/4th.This has just limited the performance of conventional motors function greatly, and efficient is also on the low side.
Purpose of the present invention, be at and overcome the above-mentioned significant deficiency of conventional motors, belt steel motor mechanism according to circuit and magnetic circuit unification, make and a kind ofly make the whole inner and outer round surface slotless of its stator and rotor, and comprise that the whole air gap area of end winding length all can produce the small size in effective air gap magnetic field, big capacity, high efficiency belt steel motor.
When belt steel motor was motor (belong to induction motor category), main points of the present invention were that its stator and rotor adopt a kind of electrical pure iron band coiled of surperficial tape insulation lacquer, and it is the conductive winding of motor, is the conducting magnet core of motor again.Realize the concrete grammar of these main points, existing by being with steel stator winding and band steel rotor two large divisions to be described below.
Belt steel motor (comprising motor and the generator) stator of double-deck end is the half turn band steel coil of some shapes and size basically identical, be close to a face of cylinder at the bottom of its sheet and be arranged in order and repeatedly install and load onto the location garter spring, solidify the hollow cylinder of the smooth slotless of inner surface that forms again by the epoxy resin casting.Accompanying drawing 1 is for being about the structure and series connection (welding) schematic diagram of two half turn bilayer zones of stator winding steel coil of a pole span apart.Accompanying drawing 4 is a stator winding actual assembled schematic diagram.The straight line portion (1) of every half turn band steel coil is an individual layer, and the end is double-deck (respectively being oval camber line in face of cylinder bending), the head of the upper strata of end (2), lower floor (3) also has a triangular piece (4), and this triangular piece bends towards along the straight line portion with the rotating shaft radial direction and coincides.The middle part of this head triangular piece has a narrow pure iron welding thin slice (5), it will be about the upper and lower layer end of each half turn band steel coil of a pole span apart and connect welding (preferably repeatedly welding with ultrasonic wave) successively mutually to form three phase windings of entire belt steel stator, and its winding diagram as shown in Figure 2.The straight line portion center top of each half turn band steel disc has a groove, is used to install guarantee that straight line portion is close to periphery and carries out the location garter spring that epoxy is cast into cylinder, and the extraction location of double as three phase terminals.In addition, between the upper and lower layer at both ends, also respectively be with a thin insulating sleeve, it plays the isolated insulation effect between the winding of upper and lower layer end on the one hand, and prior one side also is to be used to guarantee that the lower floor end is close to periphery and carries out the location garter spring that epoxy is cast into cylinder.These location garter springs are to guarantee belt steel motor master air gap, thereby also are to guarantee the well behaved key of its whole service.Location garter spring and insulating sleeve all use insulating material (preferably plastic barrel) to make.Band steel stator piece is assembled into cylinder should the high as far as possible coefficient (comprising enamelled coating) of repeatedly pressing.
Half turn band steel coil each several part cross section all must be the trapezoid cross section according to the desired shape of cross section compression molding in position of forming stator cylinder separately, and each several part iron circuit area of section also must can pass through to guarantee main flux smoothly through checking computations.Half turn band steel coil should carry out a magnetic annealing (vacuum or protective gas) and handle before above-mentioned assembling, carried out electrophoresis plating lacquer then.
The circuit of the belt steel motor three-phase stator winding of whole double-deck end connects as shown in Figure 2, it can roughly be considered as the method for attachment of the double-deck rod-type winding of conventional motors stator, unique difference is that its straight line portion is an integral body (and rod-type two layer winding straight line portion is be separated into mutual insulating upper and lower two-layer, and each is connected with own corresponding upper and lower layer end).Arbitrary equivalent circuit can find out that its difference is in analysis conventional motors and the belt steel motor three-phase, the former upper and lower layer winding respectively forms two separate branches that do not correlate mutually, and is equivalent to that many bonding wires are arranged between two branch roads that the latter forms (being to be connected by straight line portion between upper and lower layer two circuit that form of every half turn band steel coil).
Though the resistivity of electrical pure iron is bigger 7～8 times than copper, because its conduction cross-sectional area increases greatly, its power frequency phase resistance value is compared with copper cash, differs and not quite.But what should note a bit is because its power frequency kelvin effect is big more than copper cash, so its effective resistance coefficient must be rethought.The data that obtain from the actual measurement of simulation band steel model machine are about 1.8.However, be to get owing to the belt steel motor capacity improves greatly by improving air-gap field (being equivalent to improve voltage in fact), so comparatively speaking, the total copper loss of its stator and rotor is low more than the conventional motors with capacity still.
The core of belt steel motor is magnetic Circuit Design, and its stator magnetic circuit schematic diagram as shown in Figure 3.The band steel coil main magnetic circuit that analysis is made up of the mutual series connection of three half turns that are about a pole span apart, owing to all have lower floor's end winding of other adjacent current-carrying band steel coil to pass below its end, upper strata winding, former according to the right-hand rule: middle half turn band steel coil main magnetic circuit should be to be the first half and the symmetrical a pair of parallel circuits of latter half (following all by this forward and backward naming) of boundary with the straight line portion center line, so an analysis with its first half is that example gets final product.After the straight line of middle half turn first half and the main flux of lower floor end pass main air gap and enter the band steel rotor, divide left and right two-way to stride across a pole span and pass main air gap again, enter the straight line and the lower floor end of the left half turn and the right half turn first half of stator respectively.Its upper strata end coil is passed from the straight line and the lower floor end of left half turn first half again in wherein left road, the lower floor end of half turn first half and straight line portion in the middle of continuing to enter and form a closed main magnetic circuit.Wherein right wing again from the straight line of right half turn first half and lower floor end pass its lower floor's end coil enter in the middle of the upper strata end coil of half turn first half, the straight line of half turn first half and lower floor's end coil in the middle of continuing again to enter and form a closed main magnetic circuit.
Rational deployment according to the whole iron circuit of the band steel stator of double-deck end, each several part all must satisfy following main magnetic circuit design philosophy and a corresponding with it Analysis of Nested Design formula carries out the magnetic circuit checking computations, thereby can guarantee to provide rational main flux ferromagnetic path for it.
(1) the air gap flux density B δ close B of magnetic in accordance with regulations of turnover bottom (tooth)
ObPass the bottom turnover and assemble mouthful (the high h in this place undetermined of place
a).
(2) mouthful place's magnetic flux close B of magnetic is in accordance with regulations assembled in the turnover upper end on straight line portion
Ob(this place undetermined is long l axially to pass this place
o).
(3) the magnetic flux close B of magnetic in accordance with regulations of turnover upper end (yoke)
b(B
b=B
Ob) pass (the high h in this place undetermined of this place
b).
Make B
δ, B
Ao, B
b=B
ObAnd band steel stator design internal diameter R
Il, repeatedly press COEFFICIENT K between stator piece
Fel, main flux wave amplitude coefficient F
SDecide parameter before the design Deng being, an Analysis of Nested Design formula (summary is behind abbreviation) that then can meet premises design philosophy is:
＝（2R
il+h
a）·h
a·2F
S·K
Fel·B
ao……①
〔
+
（R
il+h
a+h
b+2）〕·R
il·B
δ
＝（R
il+h
a）·
·2F
S·K
Fel·B
ob……②
＝（2R
il+2h
a+h
b+4）·h
b……③
When belt steel motor was motor, its band steel rotor structural representation as shown in Figure 5.The yoke part (9) of rotor is to be penetrated repeatedly to press in the rotating shaft by the thin pure iron sheet that is washed into annular (there is shaft hole at the center) to form, the cylinder ring cylindrical again with certain altitude, cross section is trapezoidal rectangular pure iron sheet (10) direct-axis to arranging and repeatedly circle welding mutually (employing soldering in the hollow cylinder that forms of dress (should have high as far as possible repeatedly press coefficient) along the circumferential direction, but the magnetic conductivity of soldering opening material should be close with former pure iron sheet), the both ends of the cylinder that trapezoidal strip sheet changes, be two end ring (8) with copper melting welding with its common melting welding again, to be with steel rotor integral body to carry out vacuum epoxy casting cured then, after lathe became desired size with its cylindrical finish turning, outer round surface carries out electrophoresis plating lacquer again to be handled.The axial live part length overall of band steel motor rotor is consistent with its stator winding length overall (comprising the end winding), and also equates along main air gap between the stator and rotor in this length overall scope is long.
Each several part areas of section such as rectangular trapezoidal of rotor and yoke sheet also must have enough conductions and magnetic property to guarantee it through checking computations.In addition, rotor electrical pure iron sheet also must carry out a magnetic bright annealing and handle before carrying out above assembling.
When belt steel motor is generator, its rotor employing novel rare-earth cobalt magnetic pole (permanent magnet poles) rotor, Rare-Earth Cobalt pole wheel axial length length overall, also consistent with the length overall of its stator winding (comprising the end winding), and also identical along the distribution situation of whole main air gap between this length overall scope internal stator, rotor.
Compare with conventional motors, the belt steel motor of electromagnetism unification is except that having above-mentioned small size, big capacity (both identical iron core builds that comprise the end winding length compare), high efficiency great characteristics, also because the outer round surface of the internal circular surfaces of its stator and rotor is close to shiny surface, thereby the additional moment that forms owing to slot ripples in the conventional motors, noise, air gap Carter, particularly spuious copper, iron loss a series of disadvantages such as (this are that formation the present invention has one of high efficiency big factors) have been eliminated.Belt steel motor also has the advantage that does not consume copper material.And, because stator band steel disc coil radiating surface is big more than traditional stator copper coil radiating surface, but the heat load of its conduction aspect is little more than copper coil, so the belt steel motor load-bearing capacity of electromagnetism unification also has certain potentiality, its short-time overload capacity is strong more than conventional motors, and its useful life is also more than the traditional electrical captain.
The inventor had once made a simulation band steel model machine, correctness to the mechanism of above-mentioned belt steel motor is carried out verification experimental verification, because process conditions restriction at that time, the stator half-turn coil of this belt steel motor is individual layer (finger ends) band steel winding, thereby the half-turn coil of its whole stator system is made of two kinds of shapes, and wherein half is for having only end, upper strata (not having the lower floor end).Second half then has only lower floor end (not having the end, upper strata).The stator wiring schematic diagram as shown in Figure 6.Though the stator half-turn coil of this simulation band steel model machine is to adopt single belt steel winding, but with regard to its essence that produces main flux, be similar with formal band steel model machine of the present invention then, the scope that only formal model machine produces effective air gap magnetic field is to have enlarged greatly than the former that (the finger ends winding also can produce effective air gap magnetic field.And this point only needs can determine according to the well-known right-hand rule, must not prove with test).
During test, do a common cast-in aluminum squirrel cage formula rotor, also done a not rotor of cast aluminium (usefulness as the ferromagnetic circuit of stator main magnetic circuit only is provided) in addition.The axial length of two rotors is all the same with conventional motors.
This simulation belt steel motor is basic with reference to traditional JO
2-41-4 type motor designs, each coil part be by 44 circle band steel coil coileds, whenever is made up of 6 coil parts.The stator core internal diameter is φ 146.08mm, and external diameter is φ 233mm, and the axial length of whole stator is 300mm, and the length of rotor and live part is 102mm.
This simulation belt steel motor is tested, for ease of comparing, the test parameter unification is expressed with per unit value, is adopting the iron core of cast aluminium not (only provide rotor aspect ferromagnetic path) to the every 220V phase voltage of importing respectively mutually of the wiring schematic diagram shown in the accompanying drawing 6, to record exciting curent I
0About=0,47, look into standard value and should be I
0=0,27, the higher reason of measured value be since the main air gap (on average be about 0,5mm) that the steel model machine is with in this simulation than standard air gap (should be 0,35mm) cause bigger than normal.The empirical data of the middle-size and small-size induction motor of tradition test shows, actual air gap is more higher 30% than standard value, then exciting curent I
0Improve and to be about about 1 times, in view of the above, can be sure of that formally the main magnetic circuit with the steel model machine is unobstructed.
Secondly, the stator of this simulation band steel model machine is marked leakage reactance X
1The result of numerical value test be: the X that is folded to the one phase by its single hollow arbor braid steel coil test value again
1=0.05, in addition, by extracting the X that rotor method (stator is hollow) directly records the one phase out
1=0.053, look into standard value and should be X
1=0.062, thus confirm that formal band steel model machine main flux passes main air gap the samely and entered into rotor with conventional motors.
In addition, survey to such an extent that simulation is with the power frequency effective resistance coefficient value of steel model machine to be about about 1.7～1.8, this compares the multiple that increases with capacity conventional motors copper conductor conductive cross-sectional area with the band steel coil of formal band steel model machine, and its influence to the high efficiency of formal band steel model machine and good aspects such as temperature rise heat dispersion still is not enough to form and hinders greatly.
Through above actual test to simulation band steel model machine, each parameter r in the T type equivalent circuit diagram of the formal band of feasible expression steel model machine
1, X
1, r
m, X
n, r
2', X
2' etc., remove X
2' still do not have outside the measured value and (according to the magnetic structure of band steel rotor, can affirm X
2Not can with X
1Have and exceed to differ unexpectedly.X in addition
2' to the motor X that is far from
1Such importance), all the other all are to be based upon on the true basis, thereby can be sure of that its mechanism is reliably correct.
On the basis of having carried out above-mentioned verification experimental verification, the inventor manufactures and designs a formal band steel model machine by the following concrete technical scheme of the present invention.The stator of this machine is a three-phase and quadrupole, 4 △ (parallel branch number
=4) connection winding, whole stator circumference has 36 bilayer zone steel coil component outlines, each coil part limit has 44 half turn bilayer zone steel coils and forms, coefficient about about 0.8 (comprising enamelled coating) are repeatedly pressed in coil assembling, every trapezoidal cross-section of straight line portion of half turn bilayer zone steel coil is of a size of: go up bottom width 0.476mm, following bottom width 0.216mm, the high 82mm of sheet.Respectively be with a plastic insulation tube about thick approximately 2mm between the upper and lower layer in both ends, the every trapezoidal cross-section in end, upper strata is of a size of bottom width 0.337mm, following bottom width 0.247mm, the high 40mm of sheet; The every trapezoidal cross-section in lower floor end is of a size of bottom width 0.243mm, following bottom width 0.153mm, the high 40mm of sheet.
Every cross sectional dimensions of rectangular trapezoidal part of band steel rotor is: going up bottom width is 1mm, and following bottom width is 0.578mm, and the high 28.6mm of sheet, yoke sheet portion size are external diameter φ 78mm, and internal diameter is φ 48mm, the thick 1mm of sheet.Coefficient about about 0.9 is repeatedly pressed in the assembling of band steel rotor sheet.
Air-gap long (monolateral) is 0.4mm between stator and the rotor.
The rated capacity of this formal band steel model machine is 32～35KW, stator rated line voltage U
1=380V, rated current I
1=60.3～64.9A.Its build size and traditional JO
2The contrast of-61-4 type motor body molded dimension is listed as follows:
This formal band steel model machine and conventional motors (JO with capacity
2-72-4 type) contrast of various loss value is listed as follows:
Through entrust Shanghai branch office of Patent Office of the People's Republic of China to the United States Patent (USP) in 1964 to 1973 and 1974 world patents index to nineteen eighty-three (WPI) in the patent of relevant major country retrieve, find no the record identical with the present invention.
This Figure of description is described as follows:
Accompanying drawing 4 is formal band steel model machine stator winding actual assembled schematic diagram.
Accompanying drawing 5 is formal band steel model machine band steel rotor structural representation.(8) are band steel rotor two ends end ring (copper melting welding forms) among the figure.(9) yoke for the band steel rotor approaches the pure iron sheet.(10) for being with the trapezoidal rectangular pure iron sheet of steel rotor.
Accompanying drawing 6 is simulation band steel model machine stator wiring schematic diagram.
Accompanying drawing 7 is the half turn band steel coil schematic diagram of the double-deck end of model machine example.(11) are the main flux route signal on the half turn band steel coil among the figure.
Claims (8)
1, a kind ofly constituted and stator winding is that electrical pure iron strap coiled with surperficial tape insulation lacquer is the conductive winding of motor, is that the electromagnetism of the conducting magnet core of motor closes-the Shi belt steel motor again by stator, rotor, it is characterized in that: the straight line portion of all half turn band steel coils of stator winding is that individual layer, end are bilayer, size and dimension basically identical; Rotor structure be conventional or also be with the electrical pure iron strap coiled that surperficial tape insulation coats with lacquer be conductive winding be again that the electromagnetism of conducting magnet core closes-structure.
2, the described motor of claim 1 is characterized in that stator winding has following structure:
A, winding are the whole internal circular surfaces slotlesses that is formed along circumferential array and through resin solidification by half turn band steel coil and comprise the equal winding that can produce effective magnetic field of end winding length;
The half turn band steel coil each several part cross section of b, winding is determined by the position of forming cylinder, the end levels respectively is the both direction bending to the left and right on the face of cylinder of oval camber line, its head has a triangular piece, be bent to the axle radial direction straight line portion coincide, the middle part of triangular piece has a narrow pure iron welding thin slice, and each upper and lower layer end that is about the half-turn coil of a pole span apart is welded to each other the winding of forming the entire belt steel motor successively by the narrow pure iron welding thin slice in the middle part of the triangular piece;
C. the top in the middle of each half turn band steel coil straight line portion has the groove that is used to that the location garter spring of winding is installed and draws each phase lead-out wire;
D, between the upper and lower layer of winding overhang, a thin plastic insulation tube that upper and lower layer end winding is played isolated insulation effect and double as location garter spring is respectively arranged.
3, the described belt steel motor of claim 1, when it is that motor is when (belonging to the induction motor category), it is characterized in that being equipped with in the rotating shaft of rotor and repeatedly press the yoke that forms by annular electrical pure iron thin slice, it is trapezoidal rectangular pure iron sheet that the outer round surface upper edge circumferential array of yoke has the cross section, the cylinder that these pure iron sheets are formed, its internal circular surfaces is connected by soldering with the yoke outer round surface, the end ring that two end has the molten weldering of a good conducting metal of usefulness to form respectively makes and realizes between each sheet being electrically connected; Rotor axial live part length overall is consistent with its stator winding length overall (comprising the end winding), and also equates along main air gap between the stator in this length overall scope, rotor is long.
4, the described belt steel motor of claim 1, when it is generator, it is characterized in that the rotor of being joined is Rare-Earth Cobalt magnetic pole (permanent magnet poles) rotor, the axial length overall of Rare-Earth Cobalt pole wheel is also consistent with its stator winding (comprising the end winding) length overall, and also identical along the distribution situation of main air gap between the stator in this length overall scope, rotor.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN86100239.3A CN1004112B (en) | 1986-01-08 | 1986-01-08 | Electromachine using iron band, which combined both electric and magnetic effect (two-layer windinghead) |
| EP87100119A EP0233451A3 (en) | 1986-01-08 | 1987-01-07 | Strip steel electric machine with an electric circuit and a magnetic circuit mixed as a whole |
| AU67419/87A AU577490B2 (en) | 1986-01-08 | 1987-01-08 | Electric machine with mixed electric and magnetic circuits |
| JP256187A JPS62290331A (en) | 1986-01-08 | 1987-01-08 | Electric machine with conductive magnetic steel belt |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN86100239.3A CN1004112B (en) | 1986-01-08 | 1986-01-08 | Electromachine using iron band, which combined both electric and magnetic effect (two-layer windinghead) |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN86100239A CN86100239A (en) | 1986-07-30 |
| CN1004112B true CN1004112B (en) | 1989-05-03 |
Family
ID=4800932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN86100239.3A Expired CN1004112B (en) | 1986-01-08 | 1986-01-08 | Electromachine using iron band, which combined both electric and magnetic effect (two-layer windinghead) |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS62290331A (en) |
| CN (1) | CN1004112B (en) |
-
1986
- 1986-01-08 CN CN86100239.3A patent/CN1004112B/en not_active Expired
-
1987
- 1987-01-08 JP JP256187A patent/JPS62290331A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| CN86100239A (en) | 1986-07-30 |
| JPS62290331A (en) | 1987-12-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1289097A3 (en) | Electric machine with toroidal coils | |
| US3943391A (en) | Electromagnetic coupler having an electromagnetic winding | |
| CN1004112B (en) | Electromachine using iron band, which combined both electric and magnetic effect (two-layer windinghead) | |
| Kikuchi et al. | An interesting method for obtaining parametric motors with excellent performance | |
| SE8107665L (en) | BURLINDAD ROTOR ELECTRICAL ASYNCHRONOUS MACHINE | |
| JPS6430816U (en) | ||
| CN1003970B (en) | The belt steel motor of electromagnetism unification | |
| RU2112306C1 (en) | Plane-mounted induction motor | |
| EP0233451A2 (en) | Strip steel electric machine with an electric circuit and a magnetic circuit mixed as a whole | |
| JP2003270272A (en) | Current measuring instrument | |
| CN216721130U (en) | Capstan after DC brush motor excitation coil and armature improve | |
| SU1644301A1 (en) | Direct current machine | |
| CN221079809U (en) | Capacity-adjustable current transformer | |
| SU1642550A1 (en) | Stator of dc commutator motor | |
| CN117976377A (en) | Transformer coil with half-turn structure, winding method and transformer | |
| RU2074498C1 (en) | Three phases starting induction resistor | |
| SU1198652A1 (en) | Magnetic circuit of salient-pole stator of electric machine | |
| SU1488884A1 (en) | Inductor for thermomagnetic processing and magnetization of multiple rotor magnets | |
| CA1142567A (en) | Motor stator structure | |
| JPH0367414U (en) | ||
| SU705604A1 (en) | Rotor for inducting motor | |
| GB653758A (en) | Improvements in and relating to electric brakes | |
| JPS6235344B2 (en) | ||
| JPH04101275U (en) | DC machine armature | |
| JPS5778332A (en) | Armature |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C13 | Decision | ||
| GR02 | Examined patent application | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |