JPH1189164A - Thrust bearing of concentric biaxial simultaneous rotary device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce friction on the contact surface of a thrust bearing and to reduce the costs of equipment where the thrust bearing is applied by creating the thrust ball of the thrust bearing with a specific material and forming a concave curved surface with a specific radius of curvature at the center part of the thrust surface of an inner shaft. SOLUTION: A thrust ball 9'a of a thrust bearing 9' is created by using hard materials such as a ceramic material, a hardened and tempered carbon tool steel, and 18% Ni malaging steel being subjected to aging curing treatment. Then, the center part of a thrust surface S1 a of an inner shaft S1 is a concave curved surface S1 b with a radius of curvature of R that is approximately 1.5 to 10 times larger than the diameter of a thrust ball 9'a. Therefore, since a contact area increases and a thrust load per unit area decreases, friction decreases and the deterioration of a lubricant such as molybdenum disulfide is reduced for improved retention.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a thrust bearing, and more particularly to a thrust bearing of a concentric two-axis simultaneous rotating device used in a spinning machine or the like.

[0002]

2. Description of the Related Art A concentric two-axis simultaneous rotating device used in a conventional spinning machine will be described with reference to FIG. On the inside of the cylindrical outer shaft S ₀ is inserted the inner shaft S _1, the inner shaft S ₁ is supported via a pair of bearings 1a, 1b arranged at both ends of the outer shaft S ₀ I have. The outer shaft S ₀ is driven and rotated by a belt 3 partially wound around the outer peripheral surface thereof while being horizontally supported by a pair of support rollers 2. On the other hand, the inner shaft S
₁ at one end is protruded largely from the end portion of the outer shaft S ₀ (part of the bearing 1a), the permanent magnet is the protruding end portions constituting the rotor of the motor control rotational speed (permanent magnet synchronous motor) M 4 is mounted coaxially. A stator 6 is provided inside a casing 5 of the rotation speed control motor M. Further, the distal end of the outer shaft S ₀ and the inner shaft S ₁ is die 7,8 for spinning each integrally mounted thereon. 3 and 4 9 includes a thrust ball 9a provided at the tip of the protrusion 11a in the axial direction inwardly of the base plate 11 securing the casing 5 of the synchronous motor M, the inner shaft S ₁ This is a thrust bearing that receives a thrust load.

The outer shaft S ₀ is driven and rotated by the belt 3, and the inner shaft S ₁ is driven and rotated by the synchronous motor M. The rotations of the outer shaft S ₀ and the inner shaft S ₁ are detected by the first and second sensors 12 and 13, respectively, and when the rotation speed of the outer shaft S ₀ fluctuates according to a load or the like, this inner shaft S both axes S ₀ by changing the rotational speed of ₁ by the synchronous motor M in response to, S ₁
Is controlled so that the rotation speed difference becomes the set rotation speed.
FIG. 5 shows a prior invention of the applicant and is disclosed in Japanese Patent Application No. Hei 8-6929.
Which was filed as No. 5, a concentric two-axis simultaneous rotation apparatus at the time of applicant not yet published, by inserting the permanent magnets on the inner peripheral surface of the outer shaft S _0, the outer circumference of the inner shaft S ₁ such as copper By generating an induction torque on the inner shaft S ₁ by using the secondary conductor of the above, and using the induction torque as a part of the driving torque required for the inner shaft S ₁ , the rotation speed control motor M can be controlled. Although the size was reduced and the time for starting and stopping was shortened, the thrust bearing was the same as that shown in FIGS. Was left. In the concentric two-shaft simultaneous rotation device shown in FIGS. 3, 4, and 5, all the thrust bearings use molybdenum disulfide or a diluent lubricant.

[0004]

Referring to FIG. 3 and FIGS. 4 and 5, which are enlarged views of the portion A, FIG. 5 shows a thrust ball receiving hole provided in a protruding portion 11a of a motor housing. The ball 9a is housed and held by the caulking portion 11c (it does not normally rotate), and the inner shaft S
Constitute a thrust bearing 9 in contact ₁ of the smooth end face S ₁ a and the point and the inner shaft S ₁ and the thrust ball, unduly wear because it is a normal steel, therefore the oil as a lubricant, grease, Two It is a problem that molybdenum sulfide and the like are easily deteriorated and the frequency of replenishment (about once a month) is high, and it has been demanded to solve this problem.

[0005]

According to the present invention, a thrust ball is formed by using a hard material such as a ceramic material, a quenched and tempered carbon tool steel, and an age hardened 18% Ni maraging steel. The contact surface, which is fixed by caulking or the like (usually does not rotate) and serves as a sliding surface facing the thrust ball, has a diameter of about 1.5 to
The problem was solved by forming a concave surface having a curvature of 10 times.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

1) First Embodiment Referring to FIGS. 1 and 2 which are longitudinal cross-sectional views of a concentric two-axis simultaneous rotation device used in a spinning machine according to the present invention, and FIGS. 4 are denoted by the same reference numerals, and only the differences will be described. The thrust ball 9'a of the thrust bearing 9 'is made of ceramic material, quenched and tempered carbon tool steel, and 18% It made using rigid materials such as Ni maraging steel, the center of the thrust surface S ₁ a of the inner shaft S ₁ is the radius of curvature R of about 1.5 to 10 times the diameter of the thrust ball 9'a they become concave curved surface S ₁ b having, in the contact area is increased, is reduced wear since the thrust load is reduced per unit area, the two degradation of a lubricant such as molybdenum disulfide is reduced retention becomes good . 2) Second Embodiment A second embodiment of the present invention relates to a concentric 2
The shaft simultaneous rotation apparatus is an improvement of the one described in Japanese Patent Application No. 8-69295, which has been described with reference to FIG. The differs from the first embodiment, the permanent magnet is inserted into the inner peripheral surface of the outer shaft S _0, by placing the secondary conductor such as copper on the outer periphery of the inner shaft S _1, the inner shaft S ₁ induced rotational force is generated, but that was downsized electric motor by utilizing the induced rotational force as part of the driving rotational force required for the inner shaft S ₁ is different, the thrust surface S ₁ of the inner shaft S ₁ Since a and the thrust ball 9'a are completely the same as those in the first embodiment, description and illustration are omitted.

[0007]

According to the present invention, in the thrust bearing having the above structure, the wear on the contact surface is greatly reduced, and the frequency of replenishment of molybdenum disulfide and the diluent lubricant can be reduced to about once every several months. Since the service life of the two-shaft simultaneous rotation device is greatly extended and maintenance management is remarkably improved, there is an excellent effect that it is possible to contribute to cost reduction of equipment to which the thrust bearing of the present invention is applied.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a concentric two-axis simultaneous rotation device used in a spinning machine according to the present invention.

FIG. 2 is an enlarged view of a portion B in FIG.

FIG. 3 is a longitudinal sectional view of a concentric two-axis simultaneous rotation device used in a conventional spinning machine.

FIG. 4 is an enlarged view of a portion A in FIG. 3;

FIG. 5 is a longitudinal sectional view of a concentric two-axis simultaneous rotation device used in another conventional spinning machine.

[Explanation of symbols]

3: Belt 4: permanent magnet 9 ': thrust bearing 9'a: Thrust ball 11: Base plate 11a: protruding portion 11b: Hole 11c: caulking portion 22: secondary conductor M: permanent magnet synchronous motor S _0: Outer shaft S ₁ : inner shaft S ₁ a: thrust surface of inner shaft S ₁ b: concave curved surface R: radius of curvature

Claims (3)

[Claims] The motor has a portion which is coaxially mounted on a rotor of a rotation speed control motor and which protrudes outward beyond a casing of the control motor. An inner shaft that is axially supported via a thrust bearing having a thrust ball between a portion that protrudes inward in the axial direction from the casing inside;
An outer shaft which is coaxial with the outer periphery of a portion of the inner shaft protruding outward, is mounted via a radial bearing, and is driven by a belt hung on a part of the outer shaft. Concentric 2 that changes the rotation speed of the inner shaft to control the difference between the rotation speeds of both shafts to a set value
In the shaft simultaneous rotation device, the thrust ball is made of a hard material such as a ceramic material, a quenched and tempered carbon tool steel or an age hardened 18% Ni maraging steel, and is in contact with the thrust ball of the inner shaft. A thrust bearing for a concentric two-axis simultaneous rotation device, wherein the inner end surface is a concave surface having a radius of curvature of 1.5 to 10 times the diameter of the thrust ball. 2. A casing which is coaxially attached to a rotor of a rotational speed control motor and has a portion protruding outward beyond a casing of the control motor, and an inner end in the axial direction is flattened, and An inner shaft axially supported via a thrust bearing having a thrust ball between a member protruding inward from an inner surface of the casing axial end portion inside the casing, and an inner shaft protruding outward from the inner shaft. An outer shaft which is coaxially mounted on the outer periphery of the part via a radial bearing, and is driven by a belt hung on a part thereof;
A permanent magnet inserted into the inner peripheral surface of the outer shaft and having an arc-shaped cross section; and a secondary conductor provided on the outer peripheral surface of the inner shaft for flowing an induced current. An induced current flows through the secondary conductor due to a rotating magnetic field, and a part of a driving torque required for rotation of the inner shaft is supplied to enable a reduction in the size of the rotation speed control motor. In the apparatus, the thrust ball of the inner shaft is made of a hard material such as a ceramic material, a quenched and tempered carbon tool steel or an age-hardened 18% Ni maraging steel, and the thrust ball of the inner shaft is brought into contact with the thrust ball. A thrust bearing for a concentric two-axis simultaneous rotation device, wherein an inner end surface is a concave curved surface having a radius of curvature of 1.5 to 10 times the diameter of the thrust ball. 3. The thrust bearing according to claim 1, wherein the high-hardness material is a ceramic material.