CN105742003A - Linear variable differential transformer (LVDT) secondary coil design method and space-winding process employing same - Google Patents

Abstract

The invention relates to a linear variable differential transformer (LVDT) secondary coil design method and a space-winding process employing the same. The method comprises the following steps of 1, obtaining direct proportion of density n2 to displacement Z of a secondary coil of a sensor; 2, obtaining C=2S1/a<2>; 3, obtaining 2k-1=2m-1 and S<k>=(2m-1)S1 when k=m-1; and 4, obtaining a conclusion, wherein the turns S<k> of each step is in arithmetic progression. By the method, LVDTs with different sensitivities can be calculated, the maximum stroke length ratio of 78% can be reached, LVDT accuracy with 0.1%/F.S can be reached, and the temperature coefficient full scale is superior to 0.01%/F.S/DEG C; and except differential measurement by an ordinary LVDT, namely a linear relation between (VA-VB) and a distance, scale factor output also can be used, an error caused by unstable Vin can be eliminated, and the comprehensive consistency is smaller than 0.5%/F.S.

Description

Winding technologe between a kind of LVDT secondary coil design method and application the method

Technical field

The present invention relates to displacement transducer technology field, be specifically related to a kind of LVDT secondary coil design method and Winding technologe between application the method.

Background technology

Existing wound LVDT is unable to reach stroke and the length ratio of excellence, when reaching to measure scope equally The length of sensor is long, it is impossible to meet the harsh installation dimension requirement of the industries such as Aero-Space.Enterprise both at home and abroad The stroke of product maximum is 53% with length ratio；Existing wound LVDT Product Precision is typically at 0.25%/F S, for requiring that higher application scenario cannot meet；Existing wound LVDT overall product concordance is little In 5%/F S.

Summary of the invention

In order to solve the deficiency in the presence of prior art, the present invention proposes a kind of LVDT secondary coil design side Winding technologe between method and application the method.

A kind of LVDT secondary coil design method, described method step is as follows:

Step one: by the design theory of secondary coil, i.e. when iron core moves in coil It is constant, to make V₂Being proportional to Z, following formula to be made is set up:

-A₁(∫n_2adz-∫n_2bDz)=k₁z (1)；

If order:

n_2a=cz, n_2b=-cz (2)；

Then at a length of l of iron core_cCorresponding district's domain integral:

$\&Integral;n_{2a}dz-\&Integral;n_{2b}dz={\&Integral;}_{z-\frac{l_c}{2}}^{z+\frac{l_c}{2}}czdz-{\&Integral;}_{z-\frac{l_c}{2}}^{z+\frac{l_c}{2}}(-cz)dz=2{\mathrm{cl}}_{c}z$

Above formula is substituted in formula (2) and obtains:

K₁=-2cl_cA₁

Then V₂=K₁Z；

K₁For sensor sensitivity factor:

$K_1=-2{\mathrm{cl}}_c{A}_1=-2{\mathrm{cl}}_c{\mathrm{\&mu;}}_0{n}_{1}S\frac{dI}{dt}f\left(x\right){\mathrm{\&mu;}}_r$

Density n of sensor secondary coil is concluded that by formula (2)₂It is directly proportional to displacement Z；

Further comprising the steps of:

Step 2: each group of total number of turns N of secondary coil₂:

$N_2={\&Integral;}_0^{l_2}{n}_{2}dZ={\&Integral;}_0^{l_2}CZdZ=1/2{\mathrm{CZ}}^2{|}_0^{l_2}=1/2{{\mathrm{Cl}}_2}^2---\left(3\right);$

From formula (2) dimension, n₂It is mm for circle/mm, Z, so C dimension is circle/mm²If, C=2 circle/mm², Then N₂=(l₁/mm)²The number of turn, is divided into m decile by secondary coil along axis, and m obtains the biggest, n₂Closer to ideal Value, as m → ∞, n in theory₂=cz sets up for each point, but m can not obtain excessive, no Then wire winding cannot realize, and the least error of m is big affects the linearity, if with a length of step of a mm, then l₂Mm long loop is segmented into m=l₂/ a step, if first step coil turn is S₁Circle:

$S_1={\&Integral;}_0^{a}CZdZ=1/2{\mathrm{Ca}}^2---\left(4\right);$

So:

C=2S₁/a²(5)；

Step 3:

The kth step number of turn is:

$\begin{array}{c}{S}_K={\&Integral;}_{(k-1)a}^{ka}CZdZ={\&Integral;}_{(k-1)a}^{ka}2S_1/a^{2}ZdZ=2S_1/a^2*1/2Z^2{|}_{(k-1)a}^{ka}\\ =S_1/a^2\&lsqb;{\left(ka\right)}^2-(k-1)a^2\&rsqb;=(2k-1)S_1\end{array}---\left(6\right);$

By k=1,2,3 ... ..., m-1 substitutes in formula (6) respectively:

During k=1,2k-1=1, S_k=S₁；

During k=2,2k-1=3, S_k=3S₁；

During k=3,2k-1=5, S_k=5S₁；

During k=4,2k-1=7, S_k=7S₁；

During k=5,2k-1=9, S_k=9S₁；

During k=6,2k-1=11, S_k=11S₁；

………

During k=m-1,2k-1=2m-1, S_k=(2m-1) S₁；

Step 4: conclude that

Number of turn Sk:S of the most each step₁, 3S₁, 5S₁, 7S₁, 9S₁, 11S₁……(2m-1)S₁, Secondary coil is made up of m step, and each step number of turn is arithmetic series, and first term is S₁Tolerance d is 2S₁I.e. oblique The item number of rate is m, S₁Determining secondary voltage size, tolerance d determines level of sensitivity, and arithmetic series sum is:

$N_2=\underset{k=1}{\overset{m}{\&Sigma;}}{N}_k=\underset{k=1}{\overset{m}{\&Sigma;}}(2m-1)S_1=S_1{m}^2---\left(7\right).$

A kind of applying winding technologe between described LVDT secondary coil design method, described spaced winding processing step is such as Under:

The first step: secondary coil is divided into m section, every segment length is that amm, m and a can arbitrarily be arranged, Can meet the needs of different LVDT, every section of number of turns is arithmetic series；

Second step: m item arithmetic series sum, is secondary number of total coils N₂；

C=1, N₂Be one layer close around the number of turns；

C=3, N₂Be three layers close around the number of turns；

The design requirement of different sensitivity LVDT can be met；

3rd step: select coefficient C, determine that coil arranges.

In described 3rd step, when selecting C=1, spooling step is as follows:

(1) primary close around 7 layers, every layer 735 circle, spacing 0.204mm, 33#SPT enamel-covered wire, nominal diameter 0.198mm；

(2) from midpoint, i.e. 75mm starts the closeest around one layer of 1057.5 circle secondary I, spacing 0.070mm, and second Layer be spaced winding A, from right to left coiling, every 5mm is one section, spaced winding feature be every certain distance be change, with The number of turns to increase, spacing is reducing, and the second layer, around complete, pulls out a line to center, with left half of the Three interlayers around A start line in external connection；

(3) secondary II is also from the beginning of midpoint, the closeest around one layer of 1057.5 circle, spacing 0.07mm, second Layer is spaced winding B, from left to right coiling, and every 5mm is one section, behind midpoint, is attached directly to right one side of something around the Three layers of coiling B, from left to right until secondary II tail, terminate secondary II coiling；

(4) left one side of something of third layer, starts the A of coiling coiling to the left from midpoint, until secondary I tail end, terminates Secondary I coiling；

(5) left half of third layer A is close with right half of ground floor around, second layer spaced winding A composition secondary I；

(6) spaced winding A is 15 sections, and every section of 5mm presses arithmetic series arrangement, first term a₁=2.4, tolerance d=4.7, Until the 15th a₁₅=68.2, the right is close is also divided into 15 sections by every section of 5mm around 75mm；

(7) how to be connected into, around being connected, the key that arithmetic series is design with spaced winding encryption from spaced winding, specifically Operation is:

a₁₅=68.2；

a₁₆=68.2+4.7=72.9；

a₁₆It is that spaced winding 2.4 processes the close number of turns around 5mm；

a₁₆-2.4=72.9 2.4=70.5 encloses, and is the close number of turns around 5mm, close around 75mm, altogether 70.5x15 =1057.5 circles；

Whole one group of secondary coil takes hop count i.e. arithmetic series item number m=30, every segment length a=5mm；

Ground floor is spaced winding a₁、a₂………a15；

From 16 start be an interlayer around add last layer close around, both sums are arithmetic series value, as follows:

16th, the number of turns is 2.4+70.5=72.9；

17th, the number of turns is 7.1+70.5=77.6；

18th, the number of turns is 11.8+70.5=82.3；

19th, the number of turns is 70.5+16.5=87；

………

30th, the number of turns is 68.2+70.5=138.7；

Secondary 43#SPT enamel-covered wire, nominal diameter is 0.062mm, is 0.066mm to the maximum, close around spacing setting For 0.07mm ＞ 0.066mm.

In described 3rd step, when selecting C=3, spooling step is as follows:

(1) primary coiling: 33#SPT enamel-covered wire, nominal line footpath 0.198mm, close around four layers, every layer 450 circle, Spacing is 0.2mm；

(2) secondary rolling thread:

A) coiling is from the beginning of at midpoint i.e. 45mm, and secondary I is the closeest around three layers, and every layer 608 circle, spacing is 0.074mm, the 4th layer be close around 405.4 circle, spacing is 0.074mm, the 5th interlayer around A, close around 202.7 circle, Spacing is 0.074mm, and layer 6 is that spaced winding A pulls out a lead-out wire, with left half of 7th layer of initial in outside Connect；

B) secondary II the closeest around three layers from midpoint, every layer 608 circle, spacing 0.074mm, the 4th layer be close around, 405.4 circles, spacing is 0.074mm, and the 5th interlayer is around B, and the closeest around 202.7 circles, spacing is 0.074mm, 6th layer is spaced winding B, and subsequently around right half of layer 7, close around 405.4 circles, spacing is 0.074mm, spaced winding B, 8th interlayer is around B, and close around 202.7 circles, spacing is 0.074mm, and the 9th interlayer, around B, terminates as secondary II tail；

C) left one side of something is from the beginning of the 7th layer of midpoint, and the closeest around 405.4 circles, spacing is 0.074mm, spaced winding A, 8th interlayer is around A, and close around 202.7 circles, spacing is 0.074mm, and the 9th interlayer, around A, terminates as secondary I tail；

D) left half of 7th, 8,9 layers form secondary I whole lines with right half of 1st, 2,3,4,5,6 layers Circle；

(3) it is 90mm around linear distance, takes hop count m=30, every segment length a=3mm and divide six major parts, every part 5, Composition item number is the arithmetic series of 30；

A) spaced winding A mono-layer:

When for a₁Time, the number of turns is 4；

When for a₂Time, the number of turns is 12.1；

When for a₃Time, the number of turns is 20.2；

When for a₄Time, the number of turns is 28.3；

When for a₅Time, the number of turns is 36.5；

B) spaced winding A is close around one layer plus 15mm, altogether two-layer:

When for a₆Time, the number of turns is 44.6；

When for a₇Time, the number of turns is 52.7；

When for a₈Time, the number of turns is 60.8；

When for a₉Time, the number of turns is 68.9；

When for a₁₀Time, the number of turns is 77；

C) to add 15mm close around two-layer for spaced winding A, totally three layers:

When for a₁₁Time, the number of turns is 85.1；

When for a₁₂Time, the number of turns is 93.2；

When for a₁₃Time, the number of turns is 101.4；

When for a₁₄Time, the number of turns is 109.4；

When for a₁₅Time, the number of turns is 117.6；

D) to add 15mm close around three layers for spaced winding A, totally four layers:

When for a₁₆Time, the number of turns is 125.7；

When for a₁₇Time, the number of turns is 133.8；

When for a₁₈Time, the number of turns is 141.9；

When for a₁₉Time, the number of turns is 150；

When for a₂₀Time, the number of turns is 158.1；

E) to add 15mm close around four layers for spaced winding A, totally five layers:

When for a₂₁Time, the number of turns is 166.2；

When for a₂₂Time, the number of turns is 174.3；

When for a₂₃Time, the number of turns is 182.4；

When for a₂₄Time, the number of turns is 190.5；

When for a₂₅Time, the number of turns is 198.6；

F) to add 15mm close around five layers for spaced winding A, totally six layers:

When for a₂₆Time, the number of turns is 206.7；

When for a₂₇Time, the number of turns is 214.9；

When for a₂₈Time, the number of turns is 223；

When for a₂₉Time, the number of turns is 231.1；

When for a₃₀Time, the number of turns is 239.2.

The invention has the beneficial effects as follows: the present invention fully meets the demand of the high-end sector applications such as Aero-Space, Can be designed that the LVDT of different sensitivity, the haul distance ratio of maximum 78%, the LVDT of 0.1%/F S can be reached Precision, temperature coefficient full scale is better than 0.01%/F S/ DEG C, carries out variate i.e. except general LVDT simultaneously VA-VB with outside linear, it is also possible to scale factor export, i.e. Va-Vb/Va+Vb and distance Linear, so can eliminate and cause error because Vin is unstable, global consistency is less than 0.5%/F S. The present invention is used to can be designed that high accuracy, high stable, high concordance LVDT.

Accompanying drawing explanation

The present invention is further described with embodiment below in conjunction with the accompanying drawings.

Fig. 1 is the winding displacement schematic diagram during C=1 of the present invention；

Fig. 2 is that the arrangement of the spaced winding A during C=1 of the present invention represents intention；

Fig. 3 is that the arrangement of the spaced winding B during C=1 of the present invention represents intention；

Fig. 4 is the winding displacement schematic diagram during C=3 of the present invention；

The winding displacement schematic diagram of primary coiling when Fig. 5 is the C=3 of the present invention；

Fig. 6 is that the arrangement of the spaced winding A during C=3 of the present invention represents intention；

Fig. 7 is that the arrangement of the spaced winding B during C=3 of the present invention represents intention.

Detailed description of the invention

For the technological means making the present invention realize, creation characteristic, reach purpose and be easy to understand with effect, Below the present invention is expanded on further.

As shown in Figures 1 to 7, a kind of LVDT secondary coil design method, described method step is as follows:

Step one: by the design theory of secondary coil, i.e. when iron core moves in coil It is constant, to make V₂Being proportional to Z, following formula to be made is set up:

-A₁(∫n_2adz-∫n_2bDz)=k₁z (1)；

If order:

n_2a=cz, n_2b=-cz (2)；

Then at a length of l of iron core_cCorresponding district's domain integral:

$\&Integral;n_{2a}dz-\&Integral;n_{2b}dz={\&Integral;}_{z-\frac{l_c}{2}}^{z+\frac{l_c}{2}}czdz-{\&Integral;}_{z-\frac{l_c}{2}}^{z+\frac{l_c}{2}}(-cz)dz=2{\mathrm{cl}}_{c}z$

Above formula is substituted in formula (2) and obtains:

K₁=-2cl_cA₁；

Then V₂=K₁Z；

K₁For sensor sensitivity factor:

$K_1=-2{\mathrm{cl}}_c{A}_1=-2{\mathrm{cl}}_c{\mathrm{\&mu;}}_0{n}_{1}S\frac{dI}{dt}f\left(x\right){\mathrm{\&mu;}}_r$

Density n of sensor secondary coil is concluded that by formula (2)₂It is directly proportional to displacement Z；

Further comprising the steps of:

Step 2: each group of total number of turns N of secondary coil₂:

$N_2={\&Integral;}_0^{l_2}{n}_{2}dZ={\&Integral;}_0^{l_2}CZdZ=1/2{\mathrm{CZ}}^2{|}_0^{l_2}=1/2{{\mathrm{Cl}}_2}^2---\left(3\right);$

From formula (2) dimension, n₂It is mm for circle/mm, Z, so C dimension is circle/mm²If, C=2 circle/mm², Then N₂=(l₁/mm)²The number of turn, is divided into m decile by secondary coil along axis, and m obtains the biggest, n₂Closer to ideal Value, as m → ∞, n in theory₂=cz sets up for each point, but m can not obtain excessive, no Then wire winding cannot realize, and the least error of m is big affects the linearity, if with a length of step of a mm, then l₂Mm long loop is segmented into m=l₂/ a step, if first step coil turn is S₁Circle:

$S_1={\&Integral;}_0^{a}CZdZ=1/2{\mathrm{Ca}}^2---\left(4\right);$

So:

C=2S₁/a²(5)；

Step 3:

The kth step number of turn is:

$\begin{array}{c}{S}_K={\&Integral;}_{(k-1)a}^{ka}CZdZ={\&Integral;}_{(k-1)a}^{ka}2S_1/a^{2}ZdZ=2S_1/a^2*1/2Z^2{|}_{(k-1)a}^{ka}\\ =S_1/a^2\&lsqb;{\left(ka\right)}^2-(k-1)a^2\&rsqb;=(2k-1)S_1\end{array}---\left(6\right);$

By k=1,2,3 ... ..., m-1 substitutes in formula (6) respectively:

During k=1,2k-1=1, S_k=S₁；

During k=2,2k-1=3, S_k=3S₁；

During k=3,2k-1=5, S_k=5S₁；

During k=4,2k-1=7, S_k=7S₁；

During k=5,2k-1=9, S_k=9S₁；

During k=6,2k-1=11, S_k=11S₁；

………

During k=m-1,2k-1=2m-1, S_k=(2m-1) S₁；

Step 4: conclude that

Number of turn Sk:S of the most each step₁, 3S₁, 5S₁, 7S₁, 9S₁, 11S₁……(2m-1)S₁, Secondary coil is made up of m step, and each step number of turn is arithmetic series, and first term is S₁Tolerance d is 2S₁I.e. oblique The item number of rate is m, S₁Determining secondary voltage size, tolerance d determines level of sensitivity, and arithmetic series sum is:

$N_2=\underset{k=1}{\overset{m}{\&Sigma;}}{N}_k=\underset{k=1}{\overset{m}{\&Sigma;}}(2m-1)S_1=S_1{m}^2---\left(7\right).$

A kind of applying winding technologe between described LVDT secondary coil design method, described spaced winding processing step is such as Under:

The first step: secondary coil is divided into m section, every segment length is that amm, m and a can arbitrarily be arranged, Can meet the needs of different LVDT, every section of number of turns is arithmetic series；

Second step: m item arithmetic series sum, is secondary number of total coils N₂；

C=1, N₂Be one layer close around the number of turns；

C=3, N₂Be three layers close around the number of turns；

The design requirement of different sensitivity LVDT can be met；

3rd step: select coefficient C, determine that coil arranges.

In described 3rd step, when selecting C=1, spooling step is as follows:

(1) primary close around 7 layers, every layer 735 circle, spacing 0.204mm, 33#SPT enamel-covered wire, nominal diameter 0.198mm；

(2) from midpoint, i.e. 75mm starts the closeest around one layer of 1057.5 circle secondary I, spacing 0.070mm, and second Layer is spaced winding A, from right to left coiling, and every 5mm is one section, and every section of number of turns and spacing are shown in that Fig. 2, spaced winding feature are Every certain distance is change, and along with the number of turns increases, spacing is reducing, and the second layer, around complete, draws to center Go out a line, with left half of third layer spaced winding A start line in external connection；

(3) secondary II is also from the beginning of midpoint, the closeest around one layer of 1057.5 circle, spacing 0.07mm, second Layer is spaced winding B, from left to right coiling, and every 5mm is one section, and every section of number of turns and spacing are shown in Fig. 3, behind midpoint, It is attached directly to right one side of something around third layer coiling B, from left to right until secondary II tail, terminates secondary II coiling；

(4) left one side of something of third layer, starts the A of coiling coiling to the left from midpoint, until secondary I tail end, terminates Secondary I coiling；

(5) left half of third layer A is close with right half of ground floor around, second layer spaced winding A composition secondary I；

(6) spaced winding A is 15 sections, and every section of 5mm presses arithmetic series arrangement, first term a₁=2.4, tolerance d=4.7, Until the 15th a₁₅=68.2, the right is close is also divided into 15 sections by every section of 5mm around 75mm；

(7) how to be connected into, around being connected, the key that arithmetic series is design with spaced winding encryption from spaced winding, specifically Operation is:

a₁₅=68.2；

a₁₆=68.2+4.7=72.9；

a₁₆It is that spaced winding 2.4 processes the close number of turns around 5mm；

a₁₆-2.4=72.9 2.4=70.5 encloses, and is the close number of turns around 5mm, close around 75mm, altogether 70.5x15 =1057.5 circles；

Whole one group of secondary coil takes hop count i.e. arithmetic series item number m=30, every segment length a=5mm；

Ground floor is spaced winding a₁、a₂………a15；

From 16 start be an interlayer around add last layer close around, both sums are arithmetic series value, as follows:

16th, the number of turns is 2.4+70.5=72.9；

17th, the number of turns is 7.1+70.5=77.6；

18th, the number of turns is 11.8+70.5=82.3；

19th, the number of turns is 70.5+16.5=87；

………

30th, the number of turns is 68.2+70.5=138.7；

Secondary 43#SPT enamel-covered wire, nominal diameter is 0.062mm, is 0.066mm to the maximum, close around spacing setting For 0.07mm ＞ 0.066mm.

In described 3rd step, when selecting C=3, spooling step is as follows:

(1) primary coiling: 33#SPT enamel-covered wire, nominal line footpath 0.198mm, close around four layers, every layer 450 circle, Spacing is 0.2mm；

(2) secondary rolling thread:

A) coiling is from the beginning of at midpoint i.e. 45mm, and secondary I is the closeest around three layers, and every layer 608 circle, spacing is 0.074mm, direction of winding as shown by the arrows in Figure 4, the 4th layer be close around 405.4 circle, spacing is 0.074mm, Spaced winding A is shown in Fig. 6, and the 5th interlayer is around A, and close around 202.7 circles, spacing is 0.074mm, and layer 6 is spaced winding A pull-out A piece lead-out wire, with left half of 7th layer of initial in external connection；

B) secondary II the closeest around three layers from midpoint, every layer 608 circle, spacing 0.074mm, the 4th layer be close around, 405.4 circles, spacing is 0.074mm, and spaced winding B is shown in Fig. 7, and the 5th interlayer is around B, the closeest around 202.7 circles, spacing For 0.074mm, the 6th layer is spaced winding B, and subsequently around right half of layer 7, close around 405.4 circles, spacing is 0.074mm, spaced winding B, the 8th interlayer around B, close around 202.7 circle, spacing is 0.074mm, the 9th interlayer around B, Terminate as secondary II tail；

C) left one side of something is from the beginning of the 7th layer of midpoint, and the closeest around 405.4 circles, spacing is 0.074mm, spaced winding A, 8th interlayer is around A, and close around 202.7 circles, spacing is 0.074mm, and the 9th interlayer, around A, terminates as secondary I tail；

D) left half of 7th, 8,9 layers form secondary I whole lines with right half of 1st, 2,3,4,5,6 layers Circle；

(3) it is 90mm around linear distance, takes hop count m=30, every segment length a=3mm and divide six major parts, every part 5, Composition item number is the arithmetic series of 30；

A) spaced winding A mono-layer:

When for a₁Time, the number of turns is 4；

When for a₂Time, the number of turns is 12.1；

When for a₃Time, the number of turns is 20.2；

When for a₄Time, the number of turns is 28.3；

When for a₅Time, the number of turns is 36.5；

B) spaced winding A is close around one layer plus 15mm, altogether two-layer:

When for a₆Time, the number of turns is 44.6；

When for a₇Time, the number of turns is 52.7；

When for a₈Time, the number of turns is 60.8；

When for a₉Time, the number of turns is 68.9；

When for a₁₀Time, the number of turns is 77；

C) to add 15mm close around two-layer for spaced winding A, totally three layers:

When for a₁₁Time, the number of turns is 85.1；

When for a₁₂Time, the number of turns is 93.2；

When for a₁₃Time, the number of turns is 101.4；

When for a₁₄Time, the number of turns is 109.4；

When for a₁₅Time, the number of turns is 117.6；

D) to add 15mm close around three layers for spaced winding A, totally four layers:

When for a₁₆Time, the number of turns is 125.7；

When for a₁₇Time, the number of turns is 133.8；

When for a₁₈Time, the number of turns is 141.9；

When for a₁₉Time, the number of turns is 150；

When for a₂₀Time, the number of turns is 158.1；

E) to add 15mm close around four layers for spaced winding A, totally five layers:

When for a₂₁Time, the number of turns is 166.2；

When for a₂₂Time, the number of turns is 174.3；

When for a₂₃Time, the number of turns is 182.4；

When for a₂₄Time, the number of turns is 190.5；

When for a₂₅Time, the number of turns is 198.6；

F) to add 15mm close around five layers for spaced winding A, totally six layers:

When for a₂₆Time, the number of turns is 206.7；

When for a₂₇Time, the number of turns is 214.9；

When for a₂₈Time, the number of turns is 223；

When for a₂₉Time, the number of turns is 231.1；

When for a₃₀Time, the number of turns is 239.2.

The present invention is according to taking different C values, and the LVDT that can meet different sensitivity designs requirement, compensate for existing Between having, wound LVDT cannot arrive stroke and the length ratio of excellence, thus it is harsh to meet the industries such as Aero-Space Installation dimension requirement, applied widely.

The ultimate principle of the present invention, principal character and advantages of the present invention have more than been shown and described.The industry Skilled person will appreciate that, the present invention is not restricted to the described embodiments, in above-described embodiment and description The principle of the simply present invention described, without departing from the spirit and scope of the present invention, the present invention also can Having various changes and modifications, these changes and improvements both fall within scope of the claimed invention.The present invention Claimed scope is defined by appending claims and equivalent thereof.

Claims (4)

1. a LVDT secondary coil design method, described method step is as follows:

Step one: by the design theory of secondary coil, i.e. when iron core moves in coilμ_r It is constant, to make V₂Being proportional to Z, following formula to be made is set up:

-A₁(∫n_2adz-∫n_2bDz)=k₁z (1)；

If order:

n_2a=cz, n_2b=-cz (2)；

Then at a length of l of iron core_cCorresponding district's domain integral:

$\&Integral;n_{2a}dz-\&Integral;n_{2b}dz={\&Integral;}_{z-\frac{l_c}{2}}^{z+\frac{l_c}{2}}czdz-{\&Integral;}_{z-\frac{l_c}{2}}^{z+\frac{l_c}{2}}(-cz)dz=2{\mathrm{cl}}_{c}z$

Above formula substitutes into formula (2) obtain:

K₁=-2cl_cA₁

Then V₂=K₁Z；

K₁For sensor sensitivity factor:

$K_1=-2{\mathrm{cl}}_c{A}_1=-2{\mathrm{cl}}_c{\mathrm{\&mu;}}_0{n}_{1}S\frac{dI}{dt}f\left(x\right){\mathrm{\&mu;}}_r$

It is characterized in that: concluded that density n of sensor secondary coil by formula (2)₂It is directly proportional to displacement Z；

Further comprising the steps of:

Step 2: each group of total number of turns N of secondary coil₂:

$N_2={\&Integral;}_0^{l_2}{n}_{2}dZ={\&Integral;}_0^{l_2}CZdZ=1/2{\mathrm{CZ}}^2{|}_0^{l_2}=1/2{{\mathrm{Cl}}_2}^2---\left(3\right);$

From formula (2) dimension, n₂It is mm for circle/mm, Z, so C dimension is circle/mm²If, C=2 circle/mm², Then N₂=(l₁/mm)²The number of turn, is divided into m decile by secondary coil along axis, and m obtains the biggest, n₂Closer to ideal Value, as m → ∞, n in theory₂=cz sets up for each point, but m can not obtain excessive, no Then wire winding cannot realize, and the least error of m is big affects the linearity, if with a length of step of a mm, then l₂Mm long loop is segmented into m=l₂/ a step, if first step coil turn is S₁Circle:

$S_1={\&Integral;}_0^{a}CZdZ=1/2{\mathrm{Ca}}^2---\left(4\right);$

So:

C=2S₁/a²(5)；

Step 3:

The kth step number of turn is:

$\begin{array}{c}{S}_K={\&Integral;}_{(k-1)a}^{ka}CZdZ={\&Integral;}_{(k-1)a}^{ka}2S_1/a^{2}ZdZ=2S_1/a^2*1/2Z^2{|}_{(k-1)a}^{ka}\\ =S_1/a^2\&lsqb;{\left(ka\right)}^2-(k-1)a^2\&rsqb;=(2k-1)S_1\end{array}---\left(6\right);$

By k=1,2,3 ... ..., m-1 substitutes in formula (6) respectively:

During k=1,2k-1=1, S_k=S₁；

During k=2,2k-1=3, S_k=3S₁；

During k=3,2k-1=5, S_k=5S₁；

During k=4,2k-1=7, S_k=7S₁；

During k=5,2k-1=9, S_k=9S₁；

During k=6,2k-1=11, S_k=11S₁；

………

During k=m-1,2k-1=2m-1, S_k=(2m-1) S₁；

Step 4: conclude that

Number of turn Sk:S of the most each step₁, 3S₁, 5S₁, 7S₁, 9S₁, 11S₁……(2m-1)S₁, Secondary coil is made up of m step, and each step number of turn is arithmetic series, and first term is S₁Tolerance d is 2S₁I.e. oblique The item number of rate is m, S₁Determining secondary voltage size, tolerance d determines level of sensitivity, and arithmetic series sum is:

$N_2=\underset{k=1}{\overset{m}{\&Sigma;}}{N}_k=\underset{k=1}{\overset{m}{\&Sigma;}}(2m-1)S_1=S_1{m}^2---\left(7\right).$

2. applying a winding technologe between the described LVDT secondary coil design method of claim 1, it is special Levy and be: described spaced winding processing step is as follows:

The first step: secondary coil is divided into m section, every segment length is that amm, m and a can arbitrarily be arranged, Can meet the needs of different LVDT, every section of number of turns is arithmetic series；

Second step: m item arithmetic series sum, is secondary number of total coils N₂；

C=1, N₂Be one layer close around the number of turns；

C=3, N₂Be three layers close around the number of turns；

The design requirement of different sensitivity LVDT can be met；

3rd step: select coefficient C, determine that coil arranges.

The most according to claim 2 a kind of apply winding technologe between LVDT secondary coil design method, its Being characterised by: in described 3rd step, when selecting C=1, spooling step is as follows:

(1) primary close around 7 layers, every layer 735 circle, spacing 0.204mm, 33#SPT enamel-covered wire, nominal diameter 0.198mm；

(2) from midpoint, i.e. 75mm starts the closeest around one layer of 1057.5 circle secondary I, spacing 0.070mm, and second Layer be spaced winding A, from right to left coiling, every 5mm is one section, spaced winding feature be every certain distance be change, with The number of turns to increase, spacing is reducing, and the second layer, around complete, pulls out a line to center, with left half of the Three interlayers around A start line in external connection；

(3) secondary II is also from the beginning of midpoint, the closeest around one layer of 1057.5 circle, spacing 0.07mm, second Layer is spaced winding B, from left to right coiling, and every 5mm is one section, behind midpoint, is attached directly to right one side of something around the Three layers of coiling B, from left to right until secondary II tail, terminate secondary II coiling；

(4) left one side of something of third layer, starts the A of coiling coiling to the left from midpoint, until secondary I tail end, terminates Secondary I coiling；

(5) left half of third layer A is close with right half of ground floor around, second layer spaced winding A composition secondary I；

(6) spaced winding A is 15 sections, and every section of 5mm presses arithmetic series arrangement, first term a₁=2.4, tolerance d=4.7, Until the 15th a₁₅=68.2, the right is close is also divided into 15 sections by every section of 5mm around 75mm；

(7) how to be connected into, around being connected, the key that arithmetic series is design with spaced winding encryption from spaced winding, specifically Operation is:

a₁₅=68.2；

a₁₆=68.2+4.7=72.9；

a₁₆It is that spaced winding 2.4 processes the close number of turns around 5mm；

a₁₆-2.4=72.9 2.4=70.5 encloses, and is the close number of turns around 5mm, close around 75mm, altogether 70.5x15 =1057.5 circles；

Whole one group of secondary coil takes hop count i.e. arithmetic series item number m=30, every segment length a=5mm；

Ground floor is spaced winding a₁、a₂………a15；

From 16 start be an interlayer around add last layer close around, both sums are arithmetic series value, as follows:

16th, the number of turns is 2.4+70.5=72.9；

17th, the number of turns is 7.1+70.5=77.6；

18th, the number of turns is 11.8+70.5=82.3；

19th, the number of turns is 70.5+16.5=87；

………

30th, the number of turns is 68.2+70.5=138.7；

Secondary 43#SPT enamel-covered wire, nominal diameter is 0.062mm, is 0.066mm to the maximum, close around spacing setting For 0.07mm ＞ 0.066mm.

The most according to claim 2 a kind of apply winding technologe between LVDT secondary coil design method, its Being characterised by: in described 3rd step, when selecting C=3, spooling step is as follows:

(1) primary coiling: 33#SPT enamel-covered wire, nominal line footpath 0.198mm, close around four layers, every layer 450 circle, Spacing is 0.2mm；

(2) secondary rolling thread:

A) coiling is from the beginning of at midpoint i.e. 45mm, and secondary I is the closeest around three layers, and every layer 608 circle, spacing is 0.074mm, the 4th layer be close around 405.4 circle, spacing is 0.074mm, the 5th interlayer around A, close around 202.7 circle, Spacing is 0.074mm, and layer 6 is that spaced winding A pulls out a lead-out wire, with left half of 7th layer of initial in outside Connect；

B) secondary II the closeest around three layers from midpoint, every layer 608 circle, spacing 0.074mm, the 4th layer be close around, 405.4 circles, spacing is 0.074mm, and the 5th interlayer is around B, and the closeest around 202.7 circles, spacing is 0.074mm, 6th layer is spaced winding B, and subsequently around right half of layer 7, close around 405.4 circles, spacing is 0.074mm, spaced winding B, 8th interlayer is around B, and close around 202.7 circles, spacing is 0.074mm, and the 9th interlayer, around B, terminates as secondary II tail；

C) left one side of something is from the beginning of the 7th layer of midpoint, and the closeest around 405.4 circles, spacing is 0.074mm, spaced winding A, 8th interlayer is around A, and close around 202.7 circles, spacing is 0.074mm, and the 9th interlayer, around A, terminates as secondary I tail；

D) left half of 7th, 8,9 layers form secondary I whole lines with right half of 1st, 2,3,4,5,6 layers Circle；

(3) it is 90mm around linear distance, takes hop count m=30, every segment length a=3mm and divide six major parts, every part 5, Composition item number is the arithmetic series of 30；

A) spaced winding A mono-layer:

When for a₁Time, the number of turns is 4；

When for a₂Time, the number of turns is 12.1；

When for a₃Time, the number of turns is 20.2；

When for a₄Time, the number of turns is 28.3；

When for a₅Time, the number of turns is 36.5；

B) spaced winding A is close around one layer plus 15mm, altogether two-layer:

When for a₆Time, the number of turns is 44.6；

When for a₇Time, the number of turns is 52.7；

When for a₈Time, the number of turns is 60.8；

When for a₉Time, the number of turns is 68.9；

When for a₁₀Time, the number of turns is 77；

C) to add 15mm close around two-layer for spaced winding A, totally three layers:

When for a₁₁Time, the number of turns is 85.1；

When for a₁₂Time, the number of turns is 93.2；

When for a₁₃Time, the number of turns is 101.4；

When for a₁₄Time, the number of turns is 109.4；

When for a₁₅Time, the number of turns is 117.6；

D) to add 15mm close around three layers for spaced winding A, totally four layers:

When for a₁₆Time, the number of turns is 125.7；

When for a₁₇Time, the number of turns is 133.8；

When for a₁₈Time, the number of turns is 141.9；

When for a₁₉Time, the number of turns is 150；

When for a₂₀Time, the number of turns is 158.1；

E) to add 15mm close around four layers for spaced winding A, totally five layers:

When for a₂₁Time, the number of turns is 166.2；

When for a₂₂Time, the number of turns is 174.3；

When for a₂₃Time, the number of turns is 182.4；

When for a₂₄Time, the number of turns is 190.5；

When for a₂₅Time, the number of turns is 198.6；

F) to add 15mm close around five layers for spaced winding A, totally six layers:

When for a₂₆Time, the number of turns is 206.7；

When for a₂₇Time, the number of turns is 214.9；

When for a₂₈Time, the number of turns is 223；

When for a₂₉Time, the number of turns is 231.1；

When for a₃₀Time, the number of turns is 239.2.