JP2001132744A - Method and mechanism for shaft supporting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate rattling of a shaft without using an expensive component. SOLUTION: This supporting method of a shaft 11 is applied, when a lever 3 is rotatably supported on a main body 2 via a bearing 10 and the shaft 11. The shaft 11 is energized and supported from a lever 3 side where the bearing 10 is mounted, to one direction perpendicular to the axial direction of the shaft 11. As a supporting mechanism executing this method, an energizing means 25 mounted at the lever 3 side and energizing the shaft 11 in the direction perpendicular to the axial direction of the shaft 11 is used. When the shaft 11 is energized in one direction by the energizing means 25, the shaft 11 is held by the energizing means 25 and the bearing 10 from both sides and supported, whereby the rattling is eliminated. A flat spring 26 is used as the energizing means 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supporting a shaft which is suitable for use in a shaft which needs to be supported with high precision with no backlash, such as a shaft used in a hardness tester. It relates to a support mechanism.

[0002]

2. Description of the Related Art For example, in a hardness tester, a lever for measuring hardness is supported on the apparatus main body side via a bearing. That is, a bearing is mounted on the lever, a shaft is inserted into the bearing, and the shaft is mounted on the apparatus main body, whereby the lever is rotatably supported on the apparatus main body side.

[0003] An indenter is attached to the tip of the lever. The lever rotates about the shaft, and the indenter at the tip of the lever is pressed against the test piece to perform a hardness test.

By the way, there is always play between the bearing and the shaft. However, in a hardness tester having a structure in which the load by the lever acts on the shaft only in one direction, the play between the bearing and the shaft is not so problematic and can be ignored.

On the other hand, in a hardness tester having a structure in which a load applied by a lever acts on a shaft in multiple directions, play between the bearing and the shaft becomes a problem. Conventionally, high precision bearings or cross springs have been used to eliminate this play.

[0006]

However, when a high-precision bearing or cruciform spring is used to eliminate backlash between the bearing and the shaft, the bearing or cruciform spring itself is expensive. However, the cost of the apparatus has been increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a shaft supporting method and a supporting mechanism which can eliminate backlash of the shaft without using expensive parts. I do.

[0008]

According to a first aspect of the present invention, there is provided a method of supporting a shaft, the method comprising the steps of: In the supporting method, from the side of the main body or the rotating body to which the bearing is attached,
The shaft is supported by being urged in one direction perpendicular to the axial direction.

According to the above configuration, when the shaft is urged and supported in one direction orthogonal to the axial direction, the shaft is stabilized. That is, in a situation where loads are applied to the shaft from multiple directions by the original function of the device, if the shaft is urged in one direction with a force larger than these loads, the multidirectional load is canceled and only the urging force in one direction is applied. Can be left. When the shaft is urged in one direction by the remaining urging force, the bearing urges the shaft in the opposite direction due to the reaction. As a result, the shaft is sandwiched and supported from both sides. As a result, even if there is play between the bearing and the shaft, the play is completely eliminated.

A shaft support mechanism according to a second aspect of the present invention includes:
A shaft support mechanism that rotatably supports a rotating body via a bearing and a shaft on a main body, wherein the shaft is attached to a side of the main body or the rotating body on which the bearing is mounted, and the shaft is allowed to rotate. And a biasing means for biasing in one direction orthogonal to the axial direction.

With the above structure, when the shaft is urged in one direction by the urging means, the load in multiple directions is canceled by the same action as described above, and only the urging force in one direction can be left. That is, the force acting on the shaft can be limited to only the urging force in one direction by the urging means. As a result, the shaft is sandwiched and supported by the biasing means and the bearing from both sides. Thereby, even if there is a play between the bearing and the shaft, the play is completely eliminated.

[0012] A shaft support mechanism according to a third aspect of the present invention includes:
In the shaft support mechanism according to a second aspect of the present invention, the urging means urges the shaft in one direction orthogonal to the axial direction by abutting a distal end of the urging means with the base end fixed. It is characterized by being constituted by a leaf spring.

With the above configuration, when the shaft is urged in one direction by the tip of the leaf spring, the load in multiple directions is canceled by the same action as described above, and only the urging force in one direction can be left. That is, the force acting on the shaft can be only the urging force in one direction by the leaf spring. As a result, the shaft is sandwiched and supported by the leaf spring and the bearing from both sides. Thereby, even if there is a play between the bearing and the shaft, the play is completely eliminated.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a lever of the hardness tester according to the present embodiment, FIG. 2 is a side view showing the lever of the hardness tester according to the present embodiment, and FIG. FIG. 4 is a front view showing a hardness tester according to the present embodiment.

First, a hardness tester 1 will be described as an example of an apparatus using the shaft support method and the support mechanism of the present invention. As shown in FIG. 1, the hardness tester 1 mainly includes a main body 2, a lever 3, a load generating device 4, a dead weight canceller 5, and a lifting device 6.

The main body 2 is for supporting each member such as the lever 3 and the like. A lever 3 is rotatably attached to the upper end of the main body 2. A load generating device 4 is provided near the lower center of the main body 2 and is connected to the lever 3. A self-weight canceller 5 is provided near the base end of the lever 3. An elevating device 6 is provided at a position on the distal end side of the lever 3 in the main body 2.

The lever 3 is, as shown in FIGS.
It is a member for supporting an indenter (not shown) at its tip. The base end of the lever 3 is rotatably supported by the main body 2 via a bearing 10 and a shaft 11. At the base end of the lever 3, a bearing support 3A is formed. The bearing support portion 3A is a member for inserting and supporting the bearing 10 therein, and includes a lever 3A.
Are provided at two places on the left and right sides at the base end of the. A bearing 10 is attached to each bearing support 3A, and a shaft 11 is passed through each bearing 10.
Are fixed to the main body 2 side, so that the lever 3 is rotatably supported by the main body 2. An indenter (not shown) of a type corresponding to the test content is attached to the tip of the lever 3. A lamp 12 for illuminating an indenter or a test piece (not shown) is provided on the lower surface of the distal end of the lever 3 as necessary.

The load generating device 4 is a device for pulling down the lever 3 as shown in FIG. When the lever 3 is pulled down by the load generating device 4, a constant load is applied to the test piece by an indenter provided at the tip of the lever 3, and a hardness test is performed. Load generator 4
Are mainly a servo motor 14, a screw rod 15, and a lifting piece 1
6 is provided. The screw rod 15 is connected to the servomotor 14 and is controlled to rotate at an accurate angle. A screw hole (not shown) is provided in the lifting piece 16, and the screw rod 15 is provided.
Is screwed. As a result, the rotation of the screw rod 15 is accurately controlled by the servomotor 14, so that the lifting and lowering piece 16 screwed to the screw rod 15 moves up and down accurately. The lifting piece 16 is connected to the lever 3 via a connecting plate 17. Thus, by accurately controlling the rotation of the servomotor 14, the lifting piece 16 moves up and down accurately, and a set load can be accurately applied to the indenter at the tip of the lever 3. Reference numeral 18 denotes an amplifier of the servomotor 14, 19 denotes an operation board, and 20 denotes a power supply board.

The self-weight canceller 5 is a device for supporting the lever 3 from below, thereby canceling the influence of the self-weight of the lever 3 during a hardness test. The self-weight canceller 5 is constituted by a spring. The self-weight canceller 5 has a lower end supported by the support portion 22 on the main body 2 side, and an upper end abuts on a lower side of the lever 3 to elastically support the lever 3. Thereby, the self-weight canceller 5 supports the self-weight of the lever 3 and eliminates the influence of the self-weight of the lever 3 during the hardness test. That is, when the load generating device 4 pulls down the lever 3 and presses the indenter against the test piece with the set load, the self-weight of the lever 3 is prevented from being affected.

The lifting device 6 supports the test piece and
This is a device for facing the indenter at the tip of. The lifting device 6 mainly includes a lifting shaft 23 and a lifting mechanism 24. The elevating shaft 23 is formed by a square screw,
It is screwed to the elevating mechanism 24 while being supported so as not to rotate. The lifting mechanism 24 includes a nut 24 </ b> A that is screwed to the lifting shaft 23. This nut part 2
4A is rotatably supported by the main body 2 side. The nut portion 24A is provided with a handle 24B. By turning the nut portion 24A while holding the handle 24B, the elevating shaft 23 can be moved up and down an exact distance. A mounting hole 23A is provided at the upper end of the elevating shaft 23, and a table-shaped anvil (not shown) for mounting a test piece is mounted in the mounting hole 23A.

[Shaft Supporting Method] Next, the shaft supporting method of the present invention applied to the hardness tester 1 having the above-described configuration will be described.

The method for supporting the shaft 11 according to the present embodiment is a method for supporting the shaft 11 by urging the shaft 11 in one direction perpendicular to the axial direction. That is, the bearing 1 is attached to the main body 2.
This is a supporting method of the shaft 11 when the lever 3 as a rotating body is rotatably supported via the shaft 0 and the shaft 11, and the shaft 11 is moved from the side of the main body 2 or the lever 3 where the bearing 10 is attached, This is a method of supporting in a direction that is orthogonal to the axial direction.

In the hardness tester 1 having the above structure, since the bearing 10 is mounted on the lever 3 side, the shaft 11 is urged and supported from the lever 3 side in one direction orthogonal to the axial direction. I do.

As described above, by urging the shaft 11 from the lever 3 side to which the bearing 10 is attached, the force acting on the shaft 11 can be urged only in one direction. That is, the self-weight canceller 5 and the lifting device 6
In a situation where loads are applied to the shaft 11 from multiple directions due to, for example, the shaft 11 has a larger force than these loads.
Is biased in one direction, the loads in multiple directions are canceled, and only the biasing force in one direction can be left. When the shaft is urged in one direction by the remaining urging force, the reaction causes the bearing 10 to urge the shaft 11 in the opposite direction. As a result, the shaft 11 is sandwiched and supported from both sides. Thereby, even if there is a play between the bearing 10 and the shaft 11, the play can be completely eliminated.

[Shaft Support Mechanism] Next, a shaft support mechanism for realizing the above-described shaft support method will be described.

In the hardness tester 1 having the above-described configuration, a portion of the bearing 10 and the shaft 11 that rotatably supports the lever 3 on the main body 2 is provided with an urging means 2 shown in FIGS.
5 are provided. The urging means 25 is attached to the lever 3 side to which the bearing 10 is attached, and urges the shaft 11 in one direction orthogonal to the axial direction while allowing the rotation thereof. The urging means 25 is specifically constituted by a leaf spring 26. This leaf spring 26
It is made of a flat band-shaped spring material, and its tip is bent toward the shaft 11 in a U-shape. The leaf spring 26 has elasticity as a whole, and elastically supports the shaft 11 by the flat plate portion 26A and the U-shaped bent portion 26B. Elastic force of plate spring 26 (force pressing shaft 11)
Is a force greater than the load applied to the shaft 11 from multiple directions by the dead weight canceller 5, the lifting device 6, etc.
The strength is set to be able to cancel these multidirectional loads.

The bent portion 26B of the leaf spring 26 comes into direct contact with the shaft 11 to generate friction. However, since the surfaces of the shaft 11 and the leaf spring 26 are hard, the frictional resistance is small. Therefore, the shaft 11 does not stop rotating due to friction with the leaf spring 26.

The urging means 25 configured as described above
The base end is fixed to the lower surface of the lever 3 with bolts 27, and the bent portion 26B at the tip abuts on the shaft 11, and attaches the shaft 11 in one direction (direction of arrow A) orthogonal to the axial direction. I'm going.

[Operation] The hardness tester 1 having the above configuration operates as follows.

First, the test piece is placed on an anvil attached to the upper end of the elevating shaft 23 of the elevating device 6, and the lever 3
Is raised toward the indenter attached to the tip of the. Next, the lever 3 is pulled down by the load generating device 4, and the indenter at the tip of the lever 3 is brought into contact with the test piece on the anvil to apply a set load. Thereafter, the lever 3 is returned to the original state, and the hardness of the test piece is measured based on the state of the depression of the test piece recessed by the indenter.

In the above hardness test, the lever 3 is accurately supported on the main body 2 by the bearing 10 and the shaft 11, and the indenter at the tip thereof is accurately brought into contact with the test piece on the anvil.

At this time, at the base end of the lever 3, the force of the load generating device 4, the force of the dead weight canceller 5, the force received from the test piece when the indenter contacts the test piece, and the like are complicatedly affected. As a result, the bearing 10 and the shaft 1
Forces in various directions are acting between them.

The forces in the various directions are canceled by the urging force of the urging means 25, and only this urging force remains.
Since the urging force of the urging means 25 urges the shaft 11 from the lever 3 side in one direction orthogonal to the axial direction, the bearing 10 urges the shaft 11 in the opposite direction due to the reaction. As a result, the shaft 11 is sandwiched and supported by the urging means 25 and the bearing 10 from both sides. As a result, even if there is play between the bearing 10 and the shaft 11, the play is substantially eliminated, and the lever 3 swings stably and accurately. Even if forces in various directions act between the bearing 10 and the shaft 11, the lever 3 does not rattle, and the indenter accurately contacts the test piece.

[Effect] As described above, since the shaft 11 is urged and supported by the urging means 25 in one direction orthogonal to the axial direction, the bearing 10 and the shaft 1 are supported.
In the case where there is play between the camera 1 and the camera 1, the play can be eliminated, and the play can be reliably prevented from occurring even after long-term use. As a result, the shaft 11 can be stably and accurately supported, and an accurate hardness test can be performed.

The shaft 11 is moved by the urging means 25 having a simple structure.
Can be accurately supported, so that it is not necessary to use a high-precision bearing or a cross spring, and the manufacturing cost of the hardness tester 1 can be reduced.

Further, since the urging means 25 has a simple structure constituted by the leaf spring 26, it can be easily mounted, can be easily applied to various existing hardness testing machines 1, and has general versatility. .

[Modifications] (1) In the above embodiment, the main body 2 and the lever 3 of the hardness tester 1 have been described as examples of the main body and the rotating body in the shaft supporting method and the supporting mechanism of the present invention. The present invention is not limited to this, and can be applied to all devices that need to accurately support a shaft. The present invention can be applied to all devices having a structure in which a rotating part is supported by a bearing and a shaft, such as a precision work machine and a precision work robot arm, in addition to the measurement device in general.

(2) In the above embodiment, the urging means 25
The leaf spring 26 is bent in a U-shape to urge it in the direction of arrow A in FIG. 3, but as shown in FIG.
You may make it urge in the direction of arrow B. Shaft 1
As long as the direction is orthogonal to the first axial direction, the same operation and effect as the above embodiment can be obtained.

(3) In the above embodiment, the urging means 25
Although the leaf spring 26 was used as the above, the present invention is not limited to this,
Any means capable of biasing the shaft 11 in one direction perpendicular to its axial direction can be used. For example, an urging means such as a coil spring or a torsion bar spring may be used instead of the leaf spring. An air suspension using air pressure, a hydraulic cylinder that elastically urges using gas pressure in an accumulator, or the like may be used. Further, an elastic member such as rubber may be used. In these cases, the same operation and effect as the above embodiment can be obtained.

(4) In the above embodiment, the urging means 25
6, the bearing 31 is attached to the shaft 11, and the leaf spring 2 is inserted through the bearing 31 as shown in FIG.
6 may be brought into contact with the shaft 11. Thereby, friction between the shaft 11 and the leaf spring 26 can be eliminated.

[0041]

As described above, according to the present invention, the following effects can be obtained.

(1) Since the shaft is urged and supported in one direction perpendicular to the axial direction, if there is play between the bearing and the shaft, the play can be eliminated. Also, it is possible to reliably prevent the occurrence of play even after long-term use.

As a result, the shaft can be stably and accurately supported, and the rotating body can be accurately rotated with respect to the main body.

(2) Since the shaft can be accurately supported by the urging means having a simple structure, it is not necessary to use a high-precision bearing or a cross spring, and the manufacturing cost of the apparatus can be reduced.

(3) Since the urging means has a simple structure, it can be easily mounted, can be easily applied to various existing devices, and is versatile.

(4) In particular, when the biasing means is constituted by a leaf spring, the structure is extremely simple and low cost, so that the play between the bearing and the shaft can be eliminated, and the manufacturing of the apparatus can be reduced. The cost can be greatly reduced, and it can be applied very easily to various existing devices.

[Brief description of the drawings]

FIG. 1 is a front view showing a lever of a hardness tester according to an embodiment of the present invention.

FIG. 2 is a side view showing a lever of the hardness tester according to the embodiment of the present invention.

FIG. 3 is a side view showing an urging unit according to the embodiment of the present invention.

FIG. 4 is a front view showing a hardness tester according to the embodiment of the present invention.

FIG. 5 is a side view showing a first modification.

FIG. 6 is a front view showing a second modification.

[Explanation of symbols]

1: Hardness tester, 2: Main body, 3: Lever, 4: Load generating device, 5: Self-weight canceller, 6: Lifting device, 10: Bearing, 11: Shaft, 12: Ramp, 14: Servo motor, 15: Screw bar, 16: lifting piece, 18: support,
19: lifting shaft, 20: lifting mechanism, 25: biasing means, 2
6: leaf spring.

Claims (3)

[Claims] 1. A method of supporting a shaft when a rotating body is rotatably supported on a main body via a bearing and a shaft, wherein the shaft is mounted on a side of the main body or the rotating body on which the bearing is mounted. A method of supporting a shaft, wherein the shaft is supported by being urged in one direction perpendicular to the axial direction. 2. A shaft support mechanism for rotatably supporting a rotating body on a main body via a bearing and a shaft, wherein the shaft is mounted on a side of the main body or the rotating body on which the bearing is mounted, and the shaft is mounted on the body. A shaft support mechanism, comprising: urging means for urging in one direction orthogonal to the axial direction thereof while allowing rotation. 3. The shaft support mechanism according to claim 2, wherein the biasing means abuts a distal end portion on the shaft with the base end portion being fixed, and makes the shaft orthogonal to its axial direction. A shaft support mechanism comprising a leaf spring biasing in one direction.