阅读说明：本技术 离心分离机 (Centrifugal separator ) 是由 三木千季 于 2019-01-10 设计创作，主要内容包括：使用加速度传感器来防止由旋转轴的位移引起的破损。本发明的离心分离机具备转子、使转子旋转的驱动源、使转子与所述驱动源结合的旋转轴、加速度传感器以及控制部。加速度传感器至少输出表示与旋转轴的轴向垂直的两个不同方向的加速度的值。控制部求出位移换算值,该位移换算值与将与基于表示加速度传感器输出的加速度的值的加速度成比例的值除以与转子的角速度的平方成比例的值而得到的值对应,在该位移换算值满足表示预先确定的位移大的位移判定基准的情况下,控制部使转子的旋转停止。(An acceleration sensor is used to prevent breakage caused by displacement of the rotating shaft. A centrifugal separator includes a rotor, a drive source for rotating the rotor, a rotating shaft for coupling the rotor to the drive source, an acceleration sensor, and a control unit. The acceleration sensor outputs at least values indicating accelerations in two different directions perpendicular to the axial direction of the rotating shaft. The control unit determines a displacement conversion value corresponding to a value obtained by dividing a value proportional to acceleration based on a value indicating the acceleration output by the acceleration sensor by a value proportional to the square of the angular velocity of the rotor, and stops the rotation of the rotor when the displacement conversion value satisfies a displacement determination criterion indicating that the displacement is large.)

1. A centrifugal separator comprising a rotor, a drive source for rotating the rotor, and a rotating shaft for coupling the rotor to the drive source,

the centrifugal separator is provided with:

an acceleration sensor that outputs at least values representing accelerations in two different directions perpendicular to an axial direction of the rotating shaft; and

and a control unit that obtains a displacement conversion value corresponding to a value obtained by dividing a value proportional to an acceleration based on a value indicating the acceleration output by the acceleration sensor by a value proportional to a square of an angular velocity of the rotor, and stops rotation of the rotor when the displacement conversion value satisfies a displacement determination criterion indicating that a predetermined displacement is large.

2. A centrifugal separator according to claim 1,

a range of values corresponding to an angular velocity at which displacement of the rotation axis of the rotor increases due to resonance is defined as a resonance region,

the control unit obtains a displacement conversion value and confirms whether or not the displacement determination criterion is satisfied when a value corresponding to the angular velocity of the rotor falls within a range of values corresponding to predetermined angular velocities lower than the resonance region.

3. A centrifugal separator according to claim 2,

the displacement conversion value is included in a range that satisfies the displacement determination criterion when the displacement conversion value is smaller than the maximum value of the displacement conversion values in the resonance region at the time of the maximum allowable imbalance.

4. A centrifugal separator according to claim 2 or 3,

the control unit obtains an acceleration corresponding value corresponding to acceleration based on a value indicating acceleration output from the acceleration sensor, and stops rotation of the rotor when the acceleration corresponding value satisfies an acceleration determination criterion indicating that the predetermined acceleration is large.

5. A centrifugal separator according to claim 4,

the control unit checks whether or not the acceleration corresponding value satisfies the acceleration determination criterion when a value corresponding to the angular velocity of the rotor is higher than the resonance region.

6. A centrifugal separator according to any one of claims 1 to 5,

the acceleration sensor also outputs a value representing the acceleration in the axial direction of the rotating shaft.

Technical Field

The present invention relates to a centrifugal separator that detects an unbalanced state and controls rotation.

Background

Imbalance in balance (a state in which the center of gravity of the entire rotor including the sample is not on the rotation axis) occurs in the rotor in a state in which the sample is placed. If the imbalance is too large, the rotor, the rotary shaft, and the like vibrate too much, which causes a failure of the centrifugal separator. Patent document 1 and the like are known as a technique for detecting vibration caused by such imbalance.

Disclosure of Invention

Problems to be solved by the invention

The centrifugal separator of patent document 1 includes an acceleration sensor that outputs values indicating accelerations in two different directions perpendicular to the axial direction of the rotation shaft of the rotor. Then, an acceleration corresponding value is obtained from values indicating accelerations in two different directions, the acceleration corresponding value corresponding to an acceleration in a direction perpendicular to the axial direction of the rotating shaft, and when the acceleration corresponding value satisfies a determination criterion indicating that the predetermined acceleration is large, the rotation of the rotor is stopped.

In the case of the centrifugal separator of patent document 1, since the rotation of the rotor is stopped based on the force applied to the vibration isolation portion of the centrifugal separator or the like, it is possible to prevent damage due to stress. However, since the acceleration is proportional to the radius of vibration and proportional to the square of the angular velocity, the influence of the angular velocity is greater than the influence of the radius. Therefore, it is difficult to prevent damage that occurs when the rotor, the hopper, the rotary shaft, and the like contact the chamber and the like, which occurs when the rotational speed (angular velocity) is low but the displacement (radius of vibration) of the rotary shaft is large.

Further, if the centrifugal separator is further provided with a displacement sensor, displacement can be detected, but since both the acceleration sensor and the displacement sensor are provided and the signals thereof are processed, the centrifugal separator becomes expensive.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent damage due to displacement of a rotary shaft by using an acceleration sensor.

Means for solving the problems

A centrifugal separator includes a rotor, a drive source for rotating the rotor, a rotating shaft for coupling the rotor to the drive source, an acceleration sensor, and a control unit. The acceleration sensor outputs at least values indicating accelerations in two different directions perpendicular to the axial direction of the rotating shaft. The control unit determines a displacement conversion value corresponding to a value obtained by dividing a value proportional to acceleration based on a value indicating the acceleration output by the acceleration sensor by a value proportional to the square of the angular velocity of the rotor, and stops the rotation of the rotor when the displacement conversion value satisfies a displacement determination criterion indicating that the displacement is large.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the centrifugal separator of the present invention, the vibration due to imbalance can be detected using the value converted into displacement without using a displacement sensor. Therefore, the rotor, the hopper, the rotary shaft, and the like can be prevented from contacting the chamber and the like.

Drawings

FIG. 1 is a diagram showing a configuration example of a centrifugal separator according to the present invention.

Fig. 2 is a view showing the drive source 120, the rotary shaft 130, the acceleration sensor 140, and the vibration isolator 160 when the section is taken along line a-a of fig. 1.

Fig. 3A is a first diagram showing the state in which the drive source 120, the rotary shaft 130, the acceleration sensor 140, and the vibration isolation unit 160 vibrate.

Fig. 3B is a second diagram showing the state in which the drive source 120, the rotary shaft 130, the acceleration sensor 140, and the vibration isolation unit 160 vibrate.

Fig. 3C is a third diagram showing the state in which the drive source 120, the rotary shaft 130, the acceleration sensor 140, and the vibration isolation unit 160 vibrate.

Fig. 4 is a graph showing a relationship between the rotational speed and the acceleration for each imbalance in a certain centrifugal separator.

Fig. 5 is a graph showing a relationship between the rotational speed and the displacement for each imbalance in a centrifugal separator.

Fig. 6 is a diagram showing a flow of processing of the control unit.

Fig. 7 is a diagram showing a process flow when both the displacement determination criterion and the acceleration determination criterion are used.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail. The same reference numerals are given to the components having the same functions, and redundant description is omitted.