Absolute value encoder and encoding method

Abstract

This application discloses an absolute value encoder and encoding method. The absolute value encoder includes: an input shaft, one end of which is connected to an external input; a reducer, including a high-speed end and a low-speed end, the high-speed end being connected to the other end of the input shaft; a rotor connected to the low-speed end of the reducer and provided with a rotor winding; a stator provided with a stator winding, the stator winding and the rotor winding being arranged opposite each other; and a cable electrically connected to the stator winding for outputting the induced voltage generated by the stator winding. This application utilizes electromagnetic induction, which not only greatly improves the environmental adaptability of the absolute value encoder but also eliminates the need for continuous power supply.

Description

Technical Field

[0001] The present application relates to the technical field of encoders, and in particular to an absolute value encoder and an encoding method. Background Art

[0002] Currently, multi-turn absolute encoders are primarily based on photoelectric principles, using photoelectric elements and counters to record the angle and number of rotations to achieve multi-turn absolute position values. However, these elements and counters have high environmental requirements and are not suitable for operating in extremely high or low temperatures (below -25°C or above 55°C). Furthermore, they require an uninterrupted power supply to maintain the counter's ability to record the angle and number of rotations over a long period of time. Summary of the Invention

[0003] The embodiments of the present application provide an absolute encoder and an encoding method to solve the problem in the prior art that multi-turn absolute encoders have high requirements for ambient temperature and require uninterrupted power supply.

[0004] In one aspect, an embodiment of the present application provides an absolute value encoder, comprising:

[0005] Input shaft, one end of which is connected to the external input;

[0006] A reducer, comprising a high-speed end and a low-speed end, wherein the high-speed end is connected to the other end of the input shaft;

[0007] A rotor connected to the low-speed end, and provided with a rotor winding;

[0008] The stator is provided with a stator winding, and the stator winding and the rotor winding are arranged opposite to each other;

[0009] The cable is electrically connected to the stator winding and is used to output the induced voltage generated by the stator winding. The cable also provides AC power to the rotor winding.

[0010] On the other hand, an embodiment of the present application further provides an absolute value encoding method, including:

[0011] Use a reducer to decelerate the external input;

[0012] The rotor is driven by the reducer to rotate, and the rotor winding provided on the rotor is connected to an AC power supply;

[0013] The stator winding provided on the stator is arranged opposite to the rotor winding, and the stator winding generates an induced voltage;

[0014] The induced voltage is output through the cable.

[0015] An absolute value encoder and encoding method in this application have the following advantages:

[0016] 1. High environmental adaptability. Traditional absolute encoders are not suitable for continuous operation in high or low temperature environments due to the high environmental requirements of their photoelectric components and counter devices. However, the device structure of the absolute encoder in this application has low ambient temperature requirements, meeting the needs of absolute encoder use under different temperature conditions.

[0017] 2. Power-off data retention. Traditional incremental encoders rely on accumulated pulses for positioning, which causes data to be reset after a power outage. Furthermore, traditional absolute encoders require a separate battery, which resets the data when the battery loses power, and the position information before the power outage is not retained. The absolute encoder in this application can retain data long-term after a power outage, and the position information before the power outage can be directly read upon powering up again. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A schematic diagram of the internal structure of an absolute value encoder provided in an embodiment of the present application.

[0020] Explanation of the accompanying numbers: 100-input shaft, 200-machine body, 300-cable, 1-reducer, 11-high-speed end, 12-low-speed end, 2-coupling, 3-rotor winding, 4-rotor, 5-stator, 6-stator winding, 7-housing. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] Figure 1 This is a schematic diagram of the internal structure of an absolute value encoder provided in an embodiment of the present application. This embodiment of the present application provides an absolute value encoder, comprising:

[0023] Input shaft 100, one end of which is connected to the external input;

[0024] The speed reducer 1 includes a high-speed end 11 and a low-speed end 12 , wherein the high-speed end 11 is connected to the other end of the input shaft 100 ;

[0025] The rotor 4 is connected to the low-speed end 12 and is provided with a rotor winding 3;

[0026] The stator 5 is provided with a stator winding 6, and the stator winding 6 and the rotor winding 3 are arranged opposite to each other;

[0027] The cable 300 is electrically connected to the stator winding 6 and is used to output the induced voltage generated by the stator winding 6 . The cable 300 also provides AC power to the rotor winding 3 .

[0028] Exemplarily, the absolute encoder of the present application mainly includes an input shaft 100, a body 200 and a cable 300. The body 200 includes a shell 7 and a reducer 1, a rotor 4 and a stator 5 arranged inside the shell 7. The input shaft 100 passes through one end of the shell 7, and the cable 300 passes through the side of the shell 7.

[0029] A plurality of gears of different sizes and meshing with each other can be provided inside the reducer 1, and the rotation speed of the external input can be greatly reduced by single-stage or multi-stage reduction, so that the rotor 4 can reflect the rotation of the external input as many circles as possible within a certain angle range, such as 90°, 180° or 360°.

[0030] In an embodiment of the present application, the cable 300 is a collection of multiple wires, which can be divided into two insulated parts. One part is used to output the induced voltage generated by the stator winding 6, and the other part provides AC power to the rotor winding 3 through a brush during the rotation of the rotor 4. Under the supply of AC power, the rotor winding 3 can generate an alternating magnetic field, and the stator winding 6 generates magnetic flux under the action of the alternating magnetic field, thereby generating an induced voltage at both ends of the stator winding 6. There is a mathematical relationship between the induced voltage and the rotation angle of the rotor 4, and there is also a mathematical relationship between the rotation angle of the rotor 4 and the rotation angle of the external input. Therefore, the angle of the external input can be determined by analyzing the induced voltage.

[0031] Furthermore, in the present application, rotor windings 3 are provided at both ends of the rotor 4, and the low-speed end 12 of the reducer 1 is connected to the rotor 4 via a coupling 2, and the output end of the coupling 2 is vertically fixedly connected to the middle of the rotor 4. The stator 5 is an annular structure, and the stator windings 6 are evenly distributed on the four equally divided points of the stator 5, wherein two stator windings 6 arranged opposite to each other form a group, and the two stator windings 6 in a group are connected end to end to form a winding, and the axis of the rotor 4 when rotating coincides with the axis of the stator 5. When the voltage V R After the sinusoidal AC power supply is applied, the induced voltages generated by the two sets of stator windings 6 are V S and V C , the induced voltage V can be obtained by Faraday's law of electromagnetic induction S and V CAnd the relationship between the rotation angle θ of the rotor 4 is as follows:

[0032] V S =sinθ×V R ×n

[0033] V C =cosθ×V R ×n

[0034]

[0035] In the above formula, n is the turns ratio of the stator winding 6 to the rotor winding 3. The above formula can be used to calculate the rotation angle of the rotor 4. The external input rotation angle can then be determined based on the reduction ratio m of the reducer 1. It should be noted that the rotor 4 must be reset before it begins to rotate. In this application, the initial position of the rotor 4 is when the rotor winding 3 is facing the stator winding 6.

[0036] With the absolute value encoder of the above structure, when power is turned off, the rotor 4 will continue to be in its current position, and when power is turned on again, the stator winding 6 can again generate the same induced voltage as before the power was turned off. After deceleration by the reducer 1, as long as the rotation angle of the rotor 4 does not exceed one cycle, which is 180° in this application, the rotation angle of the rotor 4 can still be correctly calculated when power is turned on again after power is turned off, and the rotation angle of the external input can be determined accordingly. Moreover, based on the induction form of the rotor winding 3 and the stator winding 6, the influence of the external ambient temperature will be very limited. Therefore, the absolute value encoder of this application also has strong environmental adaptability.

[0037] Based on the structure of the above absolute value encoder, an embodiment of the present application further provides an absolute value encoding method, which includes the following steps:

[0038] Use reducer 1 to reduce the speed of external input;

[0039] The reducer 1 drives the rotor 4 to rotate, and the rotor winding 3 provided on the rotor 4 is connected to an AC power supply;

[0040] The stator winding 6 provided on the stator 5 is arranged opposite to the rotor winding 3, and the stator winding 6 generates an induced voltage;

[0041] The induced voltage is output through the cable 300 .

[0042] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0043] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. An absolute value encoder, characterized in that: include: An input shaft (100), one end of which is connected to an external input; A speed reducer (1) includes a high-speed end (11) and a low-speed end (12), wherein the high-speed end (11) is connected to the other end of the input shaft (100); A rotor (4) connected to the low-speed end (12), wherein a rotor winding (3) is provided on the rotor (4); The stator (5) is provided with a stator winding (6), wherein the stator winding (6) and the rotor winding (3) are arranged opposite to each other; a cable (300) electrically connected to the stator winding (6) and used to output the induced voltage generated by the stator winding (6); the cable (300) provides AC power to the rotor winding (3) through brushes; The stator (5) is an annular structure, and the stator windings (6) are evenly distributed on four equally divided points of the stator (5), wherein two stator windings (6) arranged opposite to each other form a group, and the two stator windings (6) in a group are connected end to end to form a winding. After deceleration by the reducer (1), as long as the rotation angle of the rotor (4) does not exceed 180°, the rotation angle of the rotor (4) can still be correctly calculated after power is turned off and then on again, and the rotation angle of the external input is determined accordingly. When the voltage V R After the sinusoidal AC power supply is applied, the induced voltages generated by the two groups of stator windings (6) are V S and V C , the induced voltage V is obtained by Faraday's law of electromagnetic induction S and V C And the relationship between the rotation angle θ of the rotor (4) is as follows: In S =sinθ×V R ×n In C =cosθ×V R ×n θ=arctan( ) In the above formula, n is the coil turns ratio of the stator winding (6) and the rotor winding (3); the rotation angle of the rotor (4) is calculated by solving the above formula, and then the rotation angle of the external input is determined according to the reduction ratio m of the reducer (1).

2. An absolute value encoder according to claim 1, characterized in that: Also includes: The housing (7) is provided, wherein the reducer (1), the rotor (4) and the stator (5) are all arranged inside the housing (7), the input shaft (100) passes through one end of the housing (7), and the cable (300) passes through a side surface of the housing (7).

3. An absolute value encoder according to claim 1, characterized in that: Also includes: A coupling (2) is connected between the low-speed end (12) and the rotor (4).

4. An absolute value encoding method applied to the absolute value encoder according to claim 1, characterized in that: include: A speed reducer (1) is used to reduce the speed of the external input; The reducer (1) drives the rotor (4) to rotate, and the rotor winding (3) provided on the rotor (4) is connected to an AC power supply; A stator winding (6) provided on the stator (5) is arranged opposite to the rotor winding (3), and the stator winding (6) generates an induced voltage; The induced voltage is output through a cable (300).

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