rotary transformer

Abstract

A resolver for measuring a voltage of a second coil with high precision. The resolver is provided with: a first magnetic core that is fixed; a first coil that is wound around the first magnetic core; a second magnetic core that has a shaft portion and a protruding portion, the shaft portion being rotatably arranged on a radially outer side of the first magnetic core in a diametrically opposite manner to the first magnetic core and extending in a rotational axis direction, the protruding portion protruding toward a radially inner side; and a second coil that is wound around the second magnetic core, the resolver being provided with a voltage sensor that is mounted to an outer peripheral surface of the first magnetic core and has a sensor protruding portion that protrudes toward a corner portion formed by the shaft portion and the protruding portion of the second magnetic core.

Description

Technical Field

[0001] This utility model relates to a rotary transformer. Background Technology

[0002] Previously, a transformer was proposed that includes a first magnetic core (inner magnetic core), a first coil (winding) wound around the first magnetic core, a second magnetic core (outer magnetic core) arranged radially outside the first magnetic core opposite to the first magnetic core, and a second coil (winding) wound around the second magnetic core (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2001-76947 Utility Model Content

[0004] However, in rotary transformers where the second coil rotates together with the second magnetic core, accurately measuring the voltage of the second coil is considered an important issue. One method for measuring the voltage of the second coil is to mount a voltage sensor on the second magnetic core. However, in this method, it is difficult to route a signal line from the voltage sensor because the second magnetic core rotates. Alternatively, a method could be considered that does not mount a voltage sensor on the second magnetic core but uses a slip ring or radio waves to measure the voltage of the second coil. However, this method cannot measure the voltage of the second coil with high accuracy.

[0005] The main purpose of this rotary transformer is to measure the voltage of the second coil with high precision.

[0006] To achieve the aforementioned main objectives, the rotary transformer of this invention employs the following method.

[0007] The key features of this rotary transformer are:

[0008] The first magnetic core is fixed;

[0009] The first coil is wound on the first magnetic core;

[0010] A second magnetic core has a shaft and a protrusion. The shaft is rotatably disposed radially outward of the first magnetic core, opposite to it, and extends along the axis of rotation. The protrusion protrudes radially inward.

[0011] The second coil is wound around the second magnetic core and rotates together with the second magnetic core.

[0012] The rotary transformer includes a voltage sensor mounted on the outer peripheral surface of the first magnetic core, and has a sensor protrusion that protrudes towards the angle formed by the shaft and the protrusion of the second magnetic core.

[0013] The rotary transformer of this invention includes a voltage sensor mounted on the outer peripheral surface of a first magnetic core. The voltage sensor has a sensor protrusion that protrudes towards the angle formed by the shaft and the protrusion of a second magnetic core. By detecting leakage flux in the angle formed by the shaft and the protrusion, the voltage sensor can measure the voltage of the second coil. Thus, by using the voltage sensor, the voltage of the second coil can be measured with high accuracy. Attached Figure Description

[0014] Figure 1 This is a schematic structural diagram of a rotary transformer according to an embodiment of the present invention.

[0015] Figure 2 This is a schematic diagram of the main parts of a rotary transformer. Detailed Implementation

[0016] The embodiments of this utility model will be described with reference to the accompanying drawings. Figure 1 This is a schematic structural diagram of a rotary transformer according to an embodiment of the present invention. As shown, the rotary transformer 10 is configured to include a first magnetic core 20, a first coil 26, a second magnetic core 30, a second coil 36, and a voltage sensor 40, wherein the first magnetic core 20 is fixed and the second magnetic core 30 rotates. The rotary transformer 10 is used in a wound-rotor excitation motor. Furthermore, the rotation axis direction and radial direction of the second magnetic core 30 are as follows... Figure 2 As shown.

[0017] The first magnetic core 20 is formed as a magnetic body on the primary side of the rotary transformer 10 and is fixed with the stator of a wound excitation motor. The first magnetic core 20 includes: a first shaft portion 22, which is generally cylindrical in shape and extends along the rotation axis direction; and a first protrusion 24, which is continuous with the first shaft portion 22 and protrudes radially outward at one end of the first shaft portion 22 in the rotation axis direction and is in the shape of a flange.

[0018] The first coil 26 is formed as the primary coil of the rotary transformer 10 and is wound multiple times on the outer peripheral surface of the first shaft portion 22 of the first magnetic core 20. The first coil 26 is connected to the wiring from the power supply, i.e., the first line L1.

[0019] The second magnetic core 30 is rotatably disposed opposite to the radially outer side of the first magnetic core 20, and is formed as a magnetic body on the secondary side of the rotary transformer 10. The second magnetic core 30 includes: a second shaft portion (shaft portion) 32, which extends in a generally cylindrical shape along the rotation axis direction; and a second protrusion (protrusion portion) 34, which is continuous with the second shaft portion 32 and protrudes radially inward in a flange shape from the end of the second shaft portion 32 on the side opposite to the first shaft portion 22 in the rotation axis direction. The second magnetic core 30 is disposed in a position that allows it to rotate without contacting the first magnetic core 20, the first coil 26, and the voltage sensor 40.

[0020] The second coil 36 is formed as a coil on the secondary side of the rotary transformer 10, and is wound multiple times on the inner circumferential surface of the second shaft portion 32 of the second magnetic core 30. The second coil 36 is connected to the second line L2, which is the wiring from the wound excitation motor side. The second coil 36 is positioned to rotate together with the second magnetic core 30, but this position does not contact the first magnetic core 20, the first coil 26, or the voltage sensor 40. The second coil 36 is connected to the second line L2, which is the wiring from the wound excitation motor.

[0021] A voltage sensor 40 is mounted on the outer peripheral surface of the first magnetic core 20, facing the second magnetic core 30 radially outward from the first magnetic core 20. The voltage sensor 40 includes: a sensor shaft portion 42 extending in a generally cylindrical shape along the direction of rotation; and a sensor protrusion 44 protruding towards the angle 38 formed by the second shaft portion 32 and the second protrusion 34 of the second magnetic core 30, without contacting the second protrusion 34. The sensor protrusion 44 includes a sensor coil 46, partially exposed and partially embedded, serving as a winding. The sensor coil 46 is connected to wiring from the wound excitation motor side, i.e., sensor line Ls.

[0022] In the rotary transformer 10 configured in this way, the second magnetic core 30 and the first coil 26 rotate while the voltage of the alternating current applied via the first line L1 changes and is supplied to the second coil 36.

[0023] Next, the operation of the voltage sensor 40 installed in the rotary transformer 10 configured in this embodiment will be explained.

[0024] Figure 2 This is a schematic diagram of the main components of a rotary transformer. In the diagram, the thick arrow indicates an example of the direction of magnetic flux through the second magnetic core. (See diagram below.) Figure 2As shown, a portion of the magnetic flux passing through the second magnetic core 30 leaks out towards the inner periphery at the corner 38, cutting across the sensor coil 46 of the voltage sensor 40 and generating an induced current in the sensor coil 46. The voltage sensor 40 detects this induced current as a voltage and uses a predetermined conversion factor to detect the voltage of the second coil 36. Thus, by mounting the voltage sensor 40 on the outer peripheral surface of the first magnetic core 20 and having the sensor coil 46 at the sensor protrusion 44 protruding towards the corner 38, the voltage of the second coil 36 can be measured with high precision.

[0025] According to the rotary transformer 10 of the present embodiment described above, by providing a voltage sensor 40, the voltage of the second coil 36 can be measured with high precision. The voltage sensor 40 has a sensor protrusion 44 that is mounted on the outer peripheral surface of the first magnetic core 20 and protrudes toward the corner 38 formed by the second shaft portion 32 and the second protrusion 34 of the second magnetic core 30.

[0026] In the above embodiments, the rotary transformer 10 is used for a wound field motor, but the application of the rotary transformer 10 is not limited to wound field motors and can be used in other devices.

[0027] The correspondence between the main elements of the implementation method and the main elements of the utility model described in the "Means for Solving the Problem" column will be explained. In the implementation method, the first magnetic core 20 is equivalent to "first magnetic core", the first coil 26 is equivalent to "first coil", the second shaft 32 is equivalent to "shaft", the second protrusion 34 is equivalent to "protrusion", the second coil 36 is equivalent to "second coil", the sensor protrusion 44 is equivalent to "sensor protrusion", and the voltage sensor 40 is equivalent to "voltage sensor".

[0028] Furthermore, the correspondence between the main elements of the implementation method and the main elements of the utility model described in the "Means for Solving the Problem" column is merely an example of how the implementation method is used to specifically explain the utility model described in the "Means for Solving the Problem" column, and therefore does not limit the elements of the utility model described in the "Means for Solving the Problem" column. That is, the interpretation of the utility model described in the "Means for Solving the Problem" column should be based on the description in that column, and the implementation method is merely a specific example of the utility model described in the "Means for Solving the Problem" column.

[0029] The above describes the methods for implementing this utility model using the embodiments, but this utility model is not limited to such embodiments, and can of course be implemented in various ways without departing from the spirit of this utility model.

[0030] Industrial availability

[0031] This invention can be applied to industries such as the manufacturing of rotary transformers.

[0032] Symbol Explanation

[0033] 10-Resolver, 20-First magnetic core, 22-First shaft, 24-First protrusion, 26-First coil, 30-Second magnetic core, 32-Second shaft, 34-Second protrusion, 36-Second coil, 38-Corner, 40-Voltage sensor, 42-Sensor shaft, 44-Sensor protrusion, 46-Sensor coil, L1-First line, L2-Second line, Ls-Sensor line.

Claims

1. A rotary transformer, characterized in that, have: The first magnetic core is fixed; The first coil is wound on the first magnetic core; A second magnetic core has a shaft and a protrusion. The shaft is rotatably disposed radially outward of the first magnetic core, facing away from it, and extends along the axis of rotation. The protrusion protrudes radially inward. The second coil is wound around the second magnetic core and rotates together with the second magnetic core. The rotary transformer includes a voltage sensor mounted on the outer peripheral surface of the first magnetic core, and has a sensor protrusion that protrudes towards the angle formed by the shaft and the protrusion of the second magnetic core.

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