阅读说明：本技术 一种无刷式旋转变压器 (Brushless rotary transformer ) 是由 王宏超 于 2020-12-16 设计创作，主要内容包括：本发明属于旋转变压器领域,涉及一种无刷式旋转变压器；包括环形定子铁芯(15)及环形定子铁芯绕组(13)、环形转子铁芯(25)及环形转子铁芯绕组(23)、定子铁芯(14)及定子铁芯绕组(11)以及转子铁芯(24)及转子铁芯绕组(21)；与转子绕组平行放置着一个附加的环形转子铁芯绕组(23),该绕组(23)绕制在转子铁芯(24)上,并且其匝数相对较少,由此形成一种低通滤波的效果,可以通过输入电压和输出电压之间屏蔽一些特定频率的干扰信号；本发明所涉及的旋转变压器具有抗干扰能力强的特点,可广泛运用于恶劣环境下。(The invention belongs to the field of rotary transformers, and relates to a brushless rotary transformer; the stator comprises an annular stator core (15), an annular stator core winding (13), an annular rotor core (25), an annular rotor core winding (23), a stator core (14), a stator core winding (11), a rotor core (24) and a rotor core winding (21); an additional annular rotor core winding (23) is arranged in parallel with the rotor winding, the winding (23) is wound on the rotor core (24) and has relatively few turns, so that a low-pass filtering effect is formed, and interference signals with specific frequencies can be shielded between input voltage and output voltage; the rotary transformer has the characteristic of strong anti-interference capability, and can be widely applied to severe environments.)

1. A brushless rotary transformer is characterized by comprising an annular stator core (15), an annular stator core winding (13), an annular rotor core (25), an annular rotor core winding (23), a stator core (14), a stator core winding (11), a rotor core (24) and a rotor core winding (21); in addition, an annular rotor core winding (23) is arranged on the rotor core (24) in parallel with the rotor core winding (21), wherein the annular rotor core winding (23) forms a low-pass filter compensation working frequency.

2. The brushless resolver according to claim 1, wherein the number of turns of the annular rotor core winding (23) is greater than 1 turn and less than 1/4 of the number of turns of the rotor core winding (21).

3. The brushless resolver according to claim 1, wherein the diameter and number of turns of the annular rotor core winding (23) compensate for the phase shift, which is between 0 ° and 10 °.

4. The brushless-type rotary transformer according to claim 1, wherein the annular rotor core winding (23) has the same wire diameter as the rotor core winding (21).

5. The brushless resolver according to claim 1, wherein the annular stator winding (13) and the annular rotor winding (23) are made to maintain their functional relationship in a relatively constant state by matching the number of turns.

6. The brushless-type rotary transformer according to claim 1, wherein the annular rotor core windings (23) are wound with the same wire diameter as the rotor windings (21) or with a wire diameter corresponding to a desired phase shift.

7. The brushless-type rotary transformer according to claim 1, wherein the number of turns of the annular rotor core winding (23) is greater than 1 and less than the number of turns of the transformer rotor winding (21).

8. The brushless resolver according to claim 1, wherein the annular rotor core winding (23) modifies the corner frequency by modifying L and R by changing the number of turns or R by changing the wire cross section, thereby changing the influence of the low pass filter on the phase shift.

Technical Field

The present invention relates to a brushless resolver having a stator and a rotor. More specifically, the resolver has at least two stator windings and one rotor winding. The rotary transformer stator and the rotary transformer rotor are axially arranged. The annular stator and the annular rotor have respective windings. In addition, an additional short-circuit winding is added to the rotor.

Background

The brushless rotary transformer is composed of two groups of induction elements of an annular stator and an annular rotor. For a stator and a rotor, the mechanical rotation angle between the stator and the rotor is determined by measuring the output voltage as an angular function of the sine and cosine. The annular stator and annular rotor portions provide an input voltage to the rotor. The rotary transformers have to be operated at an alternating voltage, their transmission behavior depending on the frequency of the excitation voltage.

In a certain frequency range, the phase shift between the output voltage and the input voltage is strongly dependent on the excitation frequency. The frequency response of the phase shift has a large monotonic decrease from low to high frequencies and passes through a zero at the top of the standard operating region. Since the resolver has a signal rectifying function, the phase shift and the phase relation of the excitation signal are considered. If they are in phase, corresponds to a positive value; if they are inverted, it corresponds to a negative value. Typically, the electronics can only tolerate small additional phase shifts. Phase shifting can present some particular problems if the resolver is to operate at low frequencies.

Previously, this phase shift problem has been solved by using RC elements to generate a phase corrected reference signal from the excitation voltage. The resolvers used in the evaluation electronics are replaced by resolvers with different phase shifts, so that the phase correction elements of the evaluation electronics are modified according to their data.

According to the patent (EP0593351a1), a resolver is known in which between the stator and the ring-shaped stator, a short-circuit winding in the form of a disc or a ring is arranged to shield the ring-shaped stator from the stray magnetic flux. However, this measurement method has no effect on the phase shift between the input voltage and the output voltage.

Disclosure of Invention

The purpose of the invention is:

the object of the present invention is to provide a brushless resolver which compensates for the phase shift of the resolver itself by a simple measure which is simple in construction and does not require a large expenditure, making an external phase corrector in the evaluation electronics superfluous.

The technical scheme of the invention is as follows:

a brushless resolver, comprising: annular stator core 15 and annular stator core winding 13, annular rotor core 25 and annular rotor core winding 23, stator core 14 and stator core winding 11, and rotor core 24 and rotor core winding 21; in addition, an annular rotor core winding 23 is disposed on rotor core 24 in parallel with rotor core winding 21, wherein annular rotor core winding 23 forms a low pass filter compensating operating frequency.

The number of turns of the annular rotor core winding 23 is more than 1 turn and less than 1/4 of the number of turns of the rotor core winding 21.

The diameter and number of turns of the annular rotor core winding 23 compensate for the phase shift, which is between 0 ° and 10 °.

The annular rotor core winding 23 has the same wire diameter as the rotor core winding 21.

The number of turns of the annular stator winding 13 and the annular rotor winding 23 are matched such that their functional relationship remains relatively constant.

The annular rotor core winding 23 may be wound with the same wire diameter as the rotor winding 21 or other wire diameters corresponding to the desired phase shift may be used.

The number of turns of the toroidal rotor core winding 23 is greater than 1, but much less than the number of turns of the transformer rotor winding 21.

The annular rotor core winding 23 modifies L and R by changing the number of turns or modifies R by changing the cross section of a lead wire, modifies corner frequency, and changes the influence of a low-pass filter on phase displacement.

The invention has the advantages that:

the short-circuit winding of the rotary transformer is arranged on the rotor core and is parallel to the rotor winding. The number of turns and the wire diameter of the short-circuit winding are selected, so that the phase shift of the rotary transformer under the working frequency can be partially offset, the anti-interference capability of the rotary transformer is improved, and the rotary transformer can work under the severe environment.

Description of the drawings:

fig. 1 is a schematic diagram of an embodiment of a resolver having a shorted winding of the present invention.

Fig. 2 is a schematic cross-sectional view of the mechanical structure of an embodiment of the resolver of the present invention.

Fig. 3 is a graphical representation of the frequency phase shift curve of a resolver without a shorted winding versus the phase shift of the resolver of the invention.

FIG. 4 is a graphical representation of the circular stator-rotor function of the resolver of the present invention as a function of operating frequency.

The specific implementation scheme is as follows:

the power consumption of the toroidal rotor core winding 23 in the present invention, together with its impedance L and resistance R, has a first order low pass filtering effect on the transfer function of the rotary transformer. The corner frequency can be modified by changing the number of turns to modify L and R or changing the cross section of the wire to modify R, thereby changing the influence of the low-pass filter on the phase displacement.

The low-pass filtering is performed by a low-pass transform, the compensation by changing the relation of the number of turns does not substantially affect the phase shift, and the frequency response of the transmission relation is approximately constant. Therefore, the phase correction method is only suitable for a limited frequency range.

The toroidal rotor core winding 23 of the present invention may be wound with the same wire diameter as the rotor winding 21 or may use other wire diameters corresponding to the desired phase shift. The number of turns of annular rotor core winding 23 is greater than 1, but much less than the number of turns of transformer rotor winding 21. In standard construction of rotary transformers, the number of turns used is about 5% to 10% of the transformer rotor winding. The invention is explained in more detail below by means of exemplary embodiments with reference to the drawing.

The resolver shown in fig. 1 has two stator windings 11 and 12 arranged at a displacement of 90 ° from each other. The rotor circuit 2 is provided in the stator circuit 1 to rotate coaxially, and has a rotor winding 21 and a ring-shaped rotor winding 22. The stator windings 11 and 12 and the rotor winding 21 constitute a resolver part 3 of the resolver, and the ring-shaped stator winding 13 and the ring-shaped rotor winding 22 form a resolver part 4.

The above structure is a general structure of the resolver. Will input voltage U₀To the annular stator winding 13. This voltage is applied to the rotor winding 21 via the annular rotor winding 22, so that a corresponding output voltage is generated in the stator windings 11 and 12. Therefore, in the statorAn output voltage U is generated at the winding 11_sinGenerating an output voltage U at the stator winding 12_cos. These output voltages depend on the angular position α of the rotor winding 21 according to the following equation:

U_sin＝U₀sinα·U_cos＝U₀cosα

the factor t represents the transformation relationship of the resolver, and represents the relationship between the maximum value of the output voltage and the maximum value of the input voltage. Thus, the rotor rotation angle α can be determined by the output voltage U_sinAnd U_cosAnd (4) calculating.

In order to compensate for the phase shift between the output voltage and the input voltage due to the operating frequency, a ring-shaped rotor core winding 23 is added to the transformer 4, which is parallel to the transformer rotor winding 22. The winding can act as a low pass filter due to its impedance L and its resistance R. The windings compensate for the phase shift given the corresponding number of turns and wire cross-sectional dimensions.

Fig. 2 is a mechanical structure sectional view of the resolver of fig. 1. The spindle 20 is mounted on the housing 19 in a manner not shown. In this case, there is a hollow shaft which can be connected to the machine shaft whose angle of rotation is to be measured. The housing 10, the windings 11, 12, 13, i.e. the stator 1, is present therein. The rotor 2 is formed by a rotor shaft 20 with windings 21, 22, 23. As mentioned before, the windings are axially displaced, whereby the stator windings 11 and the windings 12 are arranged in the laminated stator core 14 so as to pass through an angle of 90 ° with the resolver component 3, while the rotor windings 21 are also arranged on the rotor core 24. The stator core 14 and the rotor core 24 are placed opposite each other to form an air gap 5. There is an axial displacement between the ring transition part 4 and the spin transition part 3. The annular segment 4 also has an annular stator core 15 on the stator, wherein the annular stator winding 13 is arranged in the annular stator core 15. Annular rotor winding 23 is on annular rotor core 25 and annular rotor winding 22 is on annular rotor core 25. The core also winds additional annular rotor core windings 23 below the rotor windings 22. Annular stator core 15 and annular rotor core 25 also form air gap 6. The housing 10 and the rotation shaft 20 are made of a non-magnetic metal, such as high-grade steel. Furthermore, connecting wires, i.e.A pair of conductors 16 for supplying an input voltage U₀And two pairs of wires 17 and 18 are passed through the housing 10 for taking the output voltage at the stator windings 11 and 12. Internally, the secondary voltage of the ring segment 4 is connected to the rotor winding 21 via a secondary voltage from the ring-shaped rotor winding 22.

Fig. 3 shows a typical curve of the phase shift of a resolver. Dashed line Ph1 represents the phase shift curve without the annular rotor core winding 23. It can be seen that this phase shift has a zero crossing at a frequency of about 5 KHz. Thus, at this frequency, almost no phase shift occurs, whereas as the frequency decreases, a positive phase shift occurs, and as the frequency increases, a negative phase shift increases.

With the annular rotor core winding 23 of the present invention having a low pass effect, the curve is shifted to achieve the curve shown by the solid line pH2 assuming a particular size of the annular rotor core winding 23. This curve has a zero crossing at 2 KHz. Thus, if the operating frequency of the resolver is 2KHz, the initial phase shift is compensated from about 15 ° to about 0 ° by the short-circuited winding.

Fig. 4 is a frequency response of the ring transition section 4. The broken line T1 indicates the relationship when no annular rotor core winding 23 is present. According to which the frequency response of the transform relation runs at an almost constant value, i.e. the specified transform relation, over a certain frequency range, i.e. above about 1 kHz. This frequency region is the standard operating region of the resolver. However, the transformation relationship is reduced by the low pass filter behavior of the toroidal rotor core winding 23 of the present invention. Therefore, the solid curve t2 is effective, and it maintains the maximum transformation relation only in a short region. Thus, the resolver can only operate with the compensated toroidal rotor core windings 23 over a relatively narrow frequency range. However, this may not be disadvantageous because the resolver is compensated for in phase displacement at a particular frequency. Some examples of actual dimensioning of the present invention are provided below.

The six-pole hollow shaft rotary transformer with the size of 21 has the working frequency of 3.3kHz, the rotor winding of the transformer has 200 turns, and various short-circuit windings are matched. Table 1 lists the following different phase shift Ph values and the different transformations resulting therefrom.

TABLE 1 conductor cross-section phase difference transformation relationship without short-circuit winding

Number of turns of coil	Coil cross section	Phase shift	Transforming the relation t
				Non-short circuit winding	/	+31°	/
6	0.0254	﹢21°	-10％
				6	0.0508	+14°	-21％
12	0.0254	+10°	-24％
				12	0.0508	-2°	-43％

As can be seen from Table 1, the cross-sectional area of the 12 turns is 0.0254mm²The phase displacement compensation of the lead wire is +10 degrees, and the cross section of 12 turns is 0.0508mm²Is overcompensated to-2. The modified transformation relation t can be additionally compensated by modifying the remaining number of turns.

Another example is a 15 size two pole hollow shaft rotary transformer with 180 turns transformer rotor winding with 3.4kHz operating frequency, equipped with a short circuit winding. The transformation relationship is kept constant by matching the annular rotor windings. The following values were generated. Without the shorted winding, the phase shift is +26 °. When the short-circuit winding has 18 turns, if the wire diameter is 0.125mm, which corresponds to the wire of the rotor winding, the phase shift is reduced to +5 °, which is sufficient for most applications.

The contents described in the above drawings should be understood as exemplary, and the present invention should not be limited to these examples, and although an exemplary example of a winding fixing structure applied to a resolver is given in the present specification, those skilled in the art may modify or equally substitute the same on the basis of the present invention. It is to be understood that such modifications and substitutions are intended to be included within the scope of the present invention.