JPH08101004A - Angle potentiometer - Google Patents

Abstract

PURPOSE: To provide an angle potentiometer in which a resistor, etc., is not damaged even when a certain large load acts on its detecting shaft and which can detect the angle of rotation of an object to be detected with accuracy and can be used as a flush type angle potentiometer, etc. CONSTITUTION: A detecting shaft 1 is installed in a housing 2 with a plurality of pre-loaded bearings 5 and 6. The pre-load is given to the bearings 5 and 6 by putting the bearings 5 and 6 between an inner race locating snap ring put on the shaft 1 and outer race locating snap ring 12 fitted to the housing 2. The rings 11 and 12 are made of an elastic material. A brush 9 which slides on a resistor 13 on the bottom 3 of the housing 2 is fitted to the inner end of the shaft 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle potentiometer which is used in agricultural machines, industrial machines and the like and is capable of detecting a rotation angle while a load is applied to a detection shaft.

[0002]

2. Description of the Related Art A conventional recess-embedding type angle-detecting potentiometer is used with a housing 58 embedded in a recess 52 of a machine body 51, as shown in the schematic view of FIG. The internal structure of the potentiometer 50 is composed of a brush 54 that moves by the detection shaft 53 and a resistor 55 that is in contact with the brush 54, and angle detection is performed by extracting the resistance value that changes depending on the rotational position of the brush 54 as a voltage value. The detection shaft 53 is connected to the operating shaft 57 of the machine body 51 via a transmission component such as a coupling 56.

[0003]

The potentiometer 50 of the conventional type is supported only by the housing 58 and the machine body 51, and the housing 5 of the detection shaft 53.
8 is supported only by oil-impregnated metal or a small rolling bearing (not shown). Therefore, when a large load is applied to the operating shaft 57 or the detection shaft 53,
Brush 54 on resistor 55 inside potentiometer 50
Is strongly pressed, and these resistor 55 and brush 54 are
May be damaged. Therefore, potentiometer 5
0 has no original detection function. In order to prevent this, it is necessary to take measures such that a load other than rotation is not applied to the detection shaft 53 before use.

An object of the present invention is to provide an angle potentiometer which can accurately detect an angle without affecting the inside even if a load other than rotation is applied to the detection shaft.

[0005]

An angle potentiometer according to the present invention is provided with an inner end of a detection shaft protruding from a housing.
It is of a type in which a brush provided in sliding contact with a resistor provided at the bottom of the housing is provided. In this structure, the detection shaft is rotatably installed in the housing via a plurality of rolling bearings arranged in the axial direction. The bottom-side bearing engages the bottom-side width surface of the outer ring with the step portion of the housing, and the front-side bearing engages the front-side width surface with the step portion provided on the detection shaft. Further, these bearings include an inner ring retaining ring that is attached to the detection shaft and engages with the width surface of the inner ring of the bottom bearing, and an outer ring retaining ring that is attached to the housing and engages with the width surface of the outer ring of the front bearing. It is sandwiched in the preload state between.

[0006]

According to this structure, since the detection shaft is supported by the housing by the plurality of preloaded bearings, even if a load is applied to the detection shaft in the axial direction or the radial direction, the bearings should support this load. It does not damage the resistor, etc. Further, since the bearing is preloaded, the detection shaft does not rattle, and the rotation angle can be accurately detected even under a load condition.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. This potentiometer is an embedded type, and the housing 2 is composed of a cylindrical housing main body 2a and a housing bottom 3, and a mounting flange 2b is integrally formed on the outer periphery of the exposed side end which is the front side of the housing main body 2a. Has been formed. The mounting flange 2b has an insertion hole 19 for a bolt 21 to be mounted on the machine body 20. A resistor base 4 is provided on the inner surface of the housing bottom 3.

The detection shaft 1 is rotatably supported at the center of the housing 1 by two rolling bearings 5 and 6 fitted side by side in the housing 2 in the axial direction, and is attached to a brush holder 8 provided at the inner end thereof. A brush 9 which is in sliding contact with the resistor base 4 of the housing bottom 3 is attached. At the exposed end of the housing 2, a seal 7 such as an oil seal is provided between the outer periphery of the detection shaft 1 and the inner surface of the housing 2.

The rolling bearings 5 and 6 are deep groove ball bearings with seals, and the outer ring spacer 1 is provided between the outer rings of both bearings 5 and 6.
0 is sandwiched. Of these bearings 5 and 6, the bottom-side width surface of the outer ring of the bottom side bearing 5 is engaged with the step portion 2c formed by the flange portion projecting to the inner circumference of the housing 2, and the front side of the front side bearing 6 is With respect to the width surface, the detection shaft 1 is formed as a stepped shaft having a narrow inner diameter and is engaged with the stepped portion 1a. Both bearings 5 and 6 are sandwiched in a preloaded state between elastic inner ring stop ring 11 and outer ring stop ring 12 which are attached to detection shaft 1 and housing 2, respectively. As a material for the inner ring stop ring 11 and the outer ring stop ring 12, an elastic material such as spring steel is preferable, but the elastic material is not necessarily required. The inner ring stop ring 11 is fitted and mounted in the stop ring groove of the rotary shaft 1 and engages with the bottom-side width surface of the inner ring of the bottom bearing 5. The outer ring retaining ring 12 is fitted into a retaining ring groove on the inner peripheral surface of the housing 2 and engages with the front side width surface of the outer ring of the front bearing 6.

The resistor base 4 of the housing bottom 3 has a resistor 13 and an electric contact piece 14, and the brush 9 of the detection shaft 1 contacts the resistor 13 and the electric contact piece 14. Make both electrically conductive. The resistor 13 is made of a conductive resin, for example, and is formed in a ring shape with a part cut off as shown in FIG. The electrical contact piece 14 is formed in a ring shape. Terminals 13a, 13b, 14a are provided on both ends of the resistor 13 and a part of the electrical contact piece 14, and the lead wire 15 (FIG. 1) connected to each terminal is led out from the hole 3a of the housing bottom 3. .

FIG. 2 shows an example of electric wiring when the angle is detected by this potentiometer. In this example, a constant voltage is applied to the resistor 13 between the terminals 13a and 13b at both ends by a DC power supply 16, and one terminal 13a and the electrical contact piece 14 are applied.
The voltmeter 17 is connected to the terminal 14a of the. By wiring in this way, the terminals 13 on both ends of the resistor 13 are
The voltage divided by the brush 9 with respect to the applied voltage between a and 13b is detected by the voltmeter 17. Therefore, the rotational position of the brush 9, that is, the rotational angle B of the detection shaft 1 from the reference point O is detected from this voltage value. A indicates the maximum detectable angle.

According to the angle potentiometer having this structure, the detection shaft 1 is supported on the housing 2 by a plurality of preloaded bearings 5 and 6, and the bearings 5 and 6 are arranged in a fitted state on the inner circumference of the housing 2. Therefore, even if a load is applied to the detection shaft 1 in the axial direction or the radial direction, the load can be supported by the bearings 5 and 6, and the brush 9 is not affected. No damage. Further, since the bearings 5 and 6 are preloaded, there is no wobbling in the axial direction of the detection shaft 1, and the rotation angle can be accurately detected even when a load is applied. This preload is applied to the elastic retaining ring 1.
Since the bearings 1 and 12 are sandwiched and applied, the bearings 5 and 6 can be easily assembled in the preloaded state.

[0013]

In the angle potentiometer of the present invention, the detection shaft is installed in the housing by a plurality of preloaded bearings. Therefore, even if a large load is applied to the detection shaft, there is no problem of damage and the load is in a loaded state. The rotation angle can be detected accurately.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram in which a plan view showing the resistor and the brush and an electric circuit diagram are combined.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

1 ... Detecting shaft, 1a ... Step, 2 ... Housing, 2b ... Flange, 2c ... Step, 3 ... Housing bottom, 4 ... Resistor base, 5, 6 ... Rolling bearing, 9 ... Brush, 10 ... Outer ring spacer , 11 ... Inner ring retaining ring, 12 ... Outer ring retaining ring, 13 ... Resistor, 20 ... Machine body

Claims (1)

[Claims] 1. A brush, which is in sliding contact with a resistor provided at the bottom of the housing, is provided at the inner end of the detection shaft protruding from the housing, and the detection shaft is provided through a plurality of rolling bearings arranged in the axial direction. It is rotatably installed in the housing, the bottom width surface of the outer ring of the bottom bearing is engaged with the step portion of the housing, and the front width surface of the front bearing is engaged with the step portion provided on the detection shaft. An inner ring retaining ring that is attached to the detection shaft and engages with the width surface of the inner ring of the bottom bearing, and an outer ring stopper that is attached to the housing and engages with the width surface of the outer ring of the front bearing. An angle potentiometer sandwiched in a preloaded state with the ring.