JPH0242242A - Fluid transmission - Google Patents

Abstract

PURPOSE:To eliminate necessity for provision of any oil storing trough and construct in a small size by varying the current value in a coil, thereby varying the kinetic energy of magnetic fluid in a fluid joint, and by controlling the torque value on the output shaft. CONSTITUTION:Material with a low relative magnetic permeability is used to a pump impeller 2, turbine impeller 4, and casing 6. When current is supplied to a coil 5, a magnetic circuit passing magnetic fluid is formed. Change of the current value in the coil 5 will vary the kinetic energy of the magnetic fluid in fluid joint to serve controlling the output shaft torque or the revolving speed of the output shaft. This eliminates any oil storing trough and makes the construction in smaller size.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a transmission using fluid used in industrial machinery and transportation.

[Conventional technology]

Conventional variable speed fluid couplings control the rotation speed of the output shaft arbitrarily by keeping the rotation speed of the input shaft constant and adjusting the flow rate of the hydraulic fluid in the fluid coupling circuit to change the torque value of the output shaft. there was.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention is that, as mentioned above, conventional variable speed fluid couplings require an oil storage tank because the flow rate of the working fluid is adjusted to change the output shaft torque value. The disadvantage was that it became larger.

[Means for solving problems]

The present invention aims to solve the above problems.

Using a magnetic fluid as the working fluid of a fluid coupling, winding a conductive coil around the outer periphery of the fluid coupling, or arranging a yoke wrapped around the conductive coil around the outer periphery to energize the conductive coil, or arranging a permanent magnet around the outer periphery. This creates a magnetic field, and a magnetic circuit is configured to connect to the magnetic fluid within the fluid coupling.

In this case, in order to make it easier for the magnetic circuit to reach the magnetic fluid in the fluid coupling, the turbine impeller and pump impeller are made of materials with low relative magnetic permeability, and the materials of other components are also Appropriate material is selected so that the magnetic circuit can be easily attached to the fluid.

In general, fluid couplings have an input shaft rotation speed of N1. Output shaft rotation speed Nx
, input shaft torque T1. If the outer diameter of the two impellers is under the output shaft torque, it is expressed as 2 f T, M'rz =, -N, -D.

K is the density and velocity ratio of the structure 2 working fluid in the circuit (N+/
Nz).

Other things being equal, is proportional to the density of the working fluid.

Therefore, in order to change the output shaft torque, it is sufficient to change K and K from the above equation.

By the way, when magnetic fluid is magnetized, it has the property of increasing the density of its brushing.

Therefore, by changing the current value of the conductive coil or changing the distance between the permanent magnet and the outer circumference of the fluid coupling, the apparent density of the magnetic fluid in the magnetic circuit will change, and the striking output shaft torque T2 will change. be able to.

In this way, by controlling the current value of the conductive coil or changing the distance between the permanent magnet and the outer circumference of the fluid coupling, the output shaft torque T2 can be controlled and the rotation speed of the output shaft can be adjusted to $II.
m.

〔Example〕

FIG. 1 is an axial sectional view showing an example of the present invention, in which 1 is an input shaft, and 2 is a pump impeller fixed to the input shaft 1. In FIG.

3 is an output shaft, and 4 is a turbine impeller fixed to the output shaft 3.

The above structure is no different from commonly used known fluid couplings, but uses a magnetic fluid as one working fluid.

5 is a conductive coil, which is wound along the outer periphery of the fixed casing 6.

7 is a yoke.

Uses magnetic fluid as the working fluid.

Pump impeller 2. Turbine impeller 4 and casing 6
Uses materials with low relative magnetic permeability.

When electricity is applied to the coil 5, a magnetic circuit is formed which conducts magnetic fluid as shown by the dotted line in the figure.

By changing the current value of the conductive coil 5, the apparent density of the magnetic fluid changes, and therefore.

As explained in the section [Means for solving the problem], the output shaft torque T2 can be controlled by $.

FIG. 2 shows an example in which a conductive coil is wound around the yoke and arranged around the yoke.

Split yokes 8 around which conductive coils 5 are wound are arranged around the outer periphery.

As in the example shown in FIG. 1, when the conductive coil 5 is energized, a magnetic circuit is formed as shown by the dotted line.

By changing the current value of the conductive coil 5, the apparent density of the magnetic fluid changes, and therefore.

In other words, the output shaft torque T2 can be controlled as explained in the section [Means for solving the problem].

Although an example of a method of configuring a magnetic circuit using permanent magnets and magnetizing the magnetic fluid in the fluid coupling is not shown, the structure is similar to that of the second example.
Since it is almost the same as the figure, it will be explained with reference to FIG.

In FIG. 2, except for the conductive coil 5, the one-segment yoke 8 is assumed to be a permanent magnet, and is arranged in two parts or in an annular shape around the outer periphery.

When controlling the output shaft torque Tz, the @ field is changed by moving a permanent magnet in the outer circumferential direction or in the axial direction.

〔Effect of the invention〕

The present invention has the following effects.

(1) The two output shaft torques can be controlled by controlling the current value of the conductive coil or by changing the distance between the permanent magnet and the outer periphery of the fluid coupling, so an oil storage tank is not required.

(2) By increasing the current value of the conductive coil or moving the permanent magnet closer to the outer periphery of the fluid coupling, the output shaft torque can be increased and the size can be reduced.

(3) Drag torque (a condition in which the input shaft rotates and the output shaft stops), which is a problem with conventional variable speed fluid couplings, can be prevented from becoming excessive by making it smaller, and is necessary at any rotation speed. A suitable output shaft torque can be obtained by increasing the current value of the conductive coil or by bringing the permanent magnet closer to the outer periphery of the fluid coupling.

[Brief explanation of the drawing]

FIG. 1 is an axial cross-sectional view showing an embodiment of the fluid transmission of the present invention in which a coil is wound around the outer periphery. FIG. 2 is an axial cross-sectional view showing an embodiment of the fluid transmission of the present invention in which a yoke having a conductive coil wound around its outer periphery is arranged. Code table 1...-Input shaft 2...Pump impeller 3...Output shaft 4...Turbine impeller 5--Conducting coil 6...Casing 7...Yoke 8...Split yoke drawing

Claims (2)

[Claims] (1) A conductive coil is wound around the outer circumference of a fluid coupling consisting of a pump impeller attached to the input shaft and a turbine impeller attached to the output shaft, or a yoke with a conductive coil wound around the outer circumference is arranged, and the fluid coupling is operated. When a magnetic fluid is used as the fluid and the conductive coil is energized, a magnetic circuit is configured to connect to the magnetic fluid in the fluid coupling, and by changing the current value of the conductive coil, the magnetic property in the fluid coupling is reduced. A fluid transmission characterized by controlling the output shaft rotation speed by changing the apparent density of the fluid and controlling the torque value of the output shaft. (2) A permanent magnet is placed around the outer periphery of a fluid coupling consisting of a pump impeller attached to the input shaft and a turbine impeller attached to the output shaft, and a magnetic fluid is used as the working fluid. By configuring the magnetic fluid to have a magnetic circuit and changing the distance between the permanent magnet and the outer periphery of the fluid coupling, the apparent density of the magnetic fluid within the fluid coupling is changed, and the torque value of the output shaft can be changed. A fluid transmission characterized in that the output shaft rotation speed is controlled by controlling the rotation speed of the output shaft.