Device for detecting the state of a machine element

Patent metadata

Field	Value
Publication number	US-9470589-B2
Application number	US-201514590221-A
Country	US
Kind code	B2
Filing date	Jan 6, 2015
Priority date	Jan 8, 2014
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A device for detecting a mechanical state of a machine element rotates about an axis, such as a shaft is formed with an actuator disposed on the machine element so as to be axially movable, an arrangement for converting a torsion of the machine element into an axial displacement of the actuator and a sensor disposed so as to be stationary relative to the machine element for detecting the axial displacement of the actuator. A mark is assigned to the actuator for detection by the sensor in order to detect the axial displacement of the actuator. A speed (n) of the machine element can be determined from the number of marks that are detected per unit of time.

First claim

What is claimed is:

1. A device for detecting the mechanical state of a machine element that rotates about an axis, comprising:
an actuator disposed on the machine element so as to be axially movable;
means for converting a torsion of the machine element into an axial displacement of the actuator; and
a sensor disposed so as to be stationary relative to the machine element for detecting the axial displacement of the actuator;
wherein a mark is provided on the actuator and detected by the sensor to detect the axial displacement of the actuator; and
wherein a speed (n) of the machine element is determined from a number of mark detections per unit of time by the sensor.

2. The device according to claim 1 , wherein mark is designed such that the axial displacement of the actuator as well as the speed (n) of the machine element is determined from measurement signals generated by the sensor.

3. The device according to claim 1 , wherein a plurality of marks are provided on and distributed over a circumference of the actuator.

4. The device according to claim 1 , where the mark is formed by a feature that is provided on the actuator for detection by the sensor in a form of an optically detectable surface design, by a magnetization of the actuator that is detectable at least in some regions or by any other type of physically detectable properties of the actuator.

5. The device according to claim 4 , wherein the feature is formed on a circumferential surface of the actuator and has a circumferential extension (I) that tapers with respect to an axial direction (z) such that a time duration of a measurement signal generated by the sensor provides information about the axial displacement of the actuator.

6. The device according to claim 5 , wherein the feature has a shape such that the time duration of the measurement signal is approximately proportional to a torsion of the machine element.

7. The device according to claim 2 , further comprising a computer device that determines a torsional moment (MT) acting on the machine element from one of the measurement signals.

8. The device according to claim 7 , wherein the computer device determines the torsional moment (MT) acting on the machine element from one of the measurement signals representing a time duration of the torsional moment (MT).

9. The device according to claim 2 , further comprising a computer device that determines the speed (n) of the machine element from the a number of the measurement signals that are detected per unit of time.

10. The device according to claim 7 , wherein the computer device determines a mechanical power transmitted by the machine element via multiplication of the torsional moment (MT) and the speed (n) of the machine element.

11. The device according to claim 1 , wherein the actuator is designed as a hollow shaft body, an annular body or both, through which the machine element is guided; and wherein the actuator is connected to the machine element by an elastic helical structure.

12. The device according to claim 11 , wherein the actuator and the elastic helical structure are designed as a common hollow body.

13. The device according to claim 1 , wherein the actuator is connected, in a first axial direction (z), to the machine element via a left-handed elastic helical structure and is connected to the machine element, in a second axial direction (-z), which is opposed to the first axial direction, via a right-handed elastic helical structure.

14. An agricultural working a vehicle comprising a device according to claim 1 .

15. An agricultural working attachment comprising a device according to claim 1 .

16. An agricultural harvesting machine comprising a device according to claim 1 .

Assignees

• Claas Selbstfahrende Erntemaschinen Gmbh

Inventors

• Ellermann Klaus
• Daehne Goetz

Classifications

• G01L3/06

  involving mechanical means for indicating · CPC title

• G01P3/36

  Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light (G01P3/68 takes precedence; gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams G01C19/64) · CPC title

• G01L3/08 Primary

  involving optical means for indicating · CPC title

• G01L5/0061

  Force sensors associated with industrial machines or actuators (for the specific machine or actuator involved see relevant class, e.g. F01, F04, F16, B66, E21) · CPC title

• G01L3/04 Primary

  wherein the torque-transmitting element comprises a torsionally-flexible shaft · CPC title