JPH0335819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary transformer, particularly a laminated rotary transformer and a method for manufacturing the same.

In general, a non-contact type rotary transformer using electromagnetic contact is used as a device to transmit signals generated in a rotating body to a fixed part, and conversely to supply signals from a fixed part to a rotating body.
It is widely used in

Rotary transformers can be divided into two types depending on their structure. One type is a flat plate in which the rotor R fixed to the rotating shaft and the stator S fixed to the non-rotating part are disc-shaped, and a flat gap is formed between the facing surfaces of both discs. Yes (Figure 1), other 1
One is the coaxial type, in which the rotor R attached to the rotating shaft and the stator S non-rotatably arranged around the rotor R are each made of a cylindrical body, with a cylindrical gap formed between them (Figure 2). . In either type, windings (for example windings 1 R , 2 _R and 1 _S , 2 _S for the first and second channels) are provided in grooves formed in the rotor R and the stator _S. Figure 3 shows the circuit connection when a rotary transformer is applied to a VTR. Magnetic heads H ₁ and H ₂ fixed to the rotating shaft have rotor windings 1 _R and
Stator windings 1 _S and 2 _S , which are connected to VTR 2R and fixed to the deck of the VTR _, are connected to the electric circuit of the VTR.

This type of rotary transformer has windings, which makes it difficult and time-consuming to manufacture.Especially for the stator S shown in Fig. 2, the windings must be placed inside the recess, which is very time-consuming. Ta. To solve this problem, a rotor and a stator are provided in which magnetic layers and conductor layers with a winding pattern are alternately laminated, and the conductors are electrically connected through holes in the magnetic material to form coils. A laminated rotary transformer has been proposed, but the manufacturing difficulties have not yet been fully resolved. Furthermore, the device obtained by this method has the disadvantage that the magnetic flux path formed is a closed magnetic path, resulting in insufficient magnetic coupling between the rotor and the stator.

The present invention aims to improve the conventional laminated rotary transformer of this type and its manufacturing method.
The rotor and stator are formed by printing a conductive paste containing metal powder and a binder on the magnetic layer to form a conductive layer with a coil pattern, and on the conductive layer, almost the entire surface of the magnetic layer is insulated with inorganic non-magnetic material. It is manufactured by forming the body layer by printing and firing the formed laminate. The thus obtained rotor is fixed to a rotating shaft such that both inorganic non-magnetic insulating layers face the stator which is disposed opposite to each other. in this way,
According to the method of the invention, the rotor and stator of a laminated rotary transformer are formed only by printing. Further, according to the configuration of the laminated rotary transformer of the present invention, the magnetic flux path formed is an open magnetic path,
Since the diffusion of magnetic lines of force to the outside is increased, sufficient magnetic coupling is obtained between the rotor and stator, and the environmental resistance such as oxidation prevention and moisture resistance of the conductor layer is improved. The nonmagnetic insulator layer is ZnO−Bi ₂ O ₃
- Can be made from a paste made from CuO-based ceramic material, glass or other inorganic insulating material powder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of the rotary transformer of the present invention will be described below along with its manufacturing process with reference to the drawings.

In FIG. 4, a circular magnetic substrate such as ferrite is prepared by printing (FIG. 4A), and conductive layers 2 (S ₁ F ₁ for the first channel and the second for channel
S ₂ F ₂ ) (Figure 4B). The conductor layer for the coil pattern is printed using a conductive paste made by mixing a binder with a metal powder, particularly a heat-resistant metal powder such as Pd, Ag-Pd (75:25 to 50:50). Next, a nonmagnetic layer 4 is printed using a paste in which ZnO-Bi ₂ O ₃ -CuO ceramic material, glass, or other inorganic insulating material powder is mixed with a binder and a solvent, leaving connection holes 3. (Figure 4C). Then, using the above-mentioned conductive paste, a leader line pattern 5 is printed from the connection hole 3 toward the periphery (FIG. 4D). After the printing process is finished,
A center hole 6 is punched out using a press machine (FIG. 4F). After drilling the shaft hole, the disk is placed in a furnace and fired,
Finished as a stator or rotor member. In the above manufacturing process, the conductor part is formed in a layer of approximately 20μ in two passes, and the insulator part is formed in a layer of approximately 20μ in thickness.
A layer of about 25 μm is formed by a diversion pass.

FIG. 5 shows a cross-sectional view of a rotary transformer assembled using the rotor and stator manufactured in this manner. Since non-magnetic layers are formed on the opposing surfaces of the rotor and stator of this rotary transformer, the magnetic flux path formed by the current flowing through the coil becomes an open magnetic path, and the lines of magnetic force are diffused to the outside, and the rotor - Magnetic coupling between stators is increased.

In the above specific example, manufacturing of one member was explained, but in actual production, a large number of members can be manufactured simultaneously by printing.

As explained in detail above, the rotary transformer of the present invention does not require time-consuming winding work, has significantly improved magnetic coupling between the rotor and stator, and is extremely suitable for mass production. , the present invention has been applied to the electronic industry, and its effects are extremely great.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views of conventional disc-shaped and coaxial rotary transformers, respectively;
The figure is a schematic connection diagram when a rotary transformer is used in a VTR, FIG. 4 is a plan view showing one specific example of the rotary transformer of the present invention in the order of manufacturing steps, and FIG.
The figure is a sectional view of one specific example of the rotary transformer of the present invention. 1: Magnetic substrate, 2: Conductor layer of coil pattern, 3: Connection hole, 4: Non-magnetic insulating layer, 5: Lead line pattern, 6: Shaft hole.

Claims (1)

[Claims] 1. A conductive layer with a coil pattern is formed on the magnetic layer by printing a conductive paste containing metal powder mixed with a binder, and an inorganic non-magnetic insulating layer is formed on the conductive layer over almost the entire surface of the magnetic layer. 1. A method for manufacturing a rotary transformer, comprising forming a body layer by printing and firing the formed laminate to form a rotor and a stator, respectively. 2. A conductor layer with a coil pattern formed by printing a conductive paste containing metal powder mixed with a binder on the magnetic layer, and an inorganic non-magnetic insulator formed on the conductor layer over almost the entire surface of the magnetic layer. It is characterized by comprising a rotor and a stator formed by firing a laminate containing the rotor, and the rotor is fixed to a rotating shaft such that the inorganic nonmagnetic insulating layers of both of the rotors face the stator. Laminated rotary transformer.