Method for detecting preload residual rate

Patent metadata

Field	Value
Publication number	US-9593987-B2
Application number	US-201414454344-A
Country	US
Kind code	B2
Filing date	Aug 7, 2014
Priority date	Jun 25, 2014
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A method for detecting a preload residual rate involves: a. installing a temperature sensor on one of two preloaded elements; b. making the two preloaded elements to move with respect to each other, and recording a time-related temperature variation sensed by the temperature sensor, so as to obtain an initial temperature-rising curve; c. making the two preloaded elements to move with respect to each other, and recording a time-related temperature variation sensed by the temperature sensor, so as to obtain a detected temperature-rising curve; and d. comparing the initial and detected temperature-rising curves, so as to obtain the preload residual rate between the two preloaded elements of the step c to the step b. The method detects a preload residual rate applied to an object when the object is operating while being advantageous in terms of cost, service life, response and accuracy.

First claim

What is claimed is:

1. A method for detecting a preload residual rate, the method comprising steps of:
a. installing a temperature sensor on one of two preloaded elements that are configured to move with respect to each other;
b. making the two preloaded elements to move with respect to each other, and simultaneously recording a time-related temperature variation sensed by the temperature sensor, so as to obtain an initial temperature-rising curve;
c. making the two preloaded elements to move with respect to each other, and simultaneously recording a time-related temperature variation sensed by the temperature sensor, so as to obtain a detected temperature-rising curve; and
d. comparing the initial temperature-rising curve with the detected temperature-rising curve, so as to obtain the preload residual rate between the two preloaded elements of the step c to the step b.

2. The method of claim 1 , wherein in the steps b and c the two preloaded elements move with respect to each other at an identical velocity.

3. The method of claim 1 , wherein the two preloaded elements are a screw and a nut of a ball screw device, and the steps a and b are performed at a manufacturer's side, while the steps c and d are performed at a user's side.

4. The method of claim 3 , wherein in the steps b and c the nut moves along the screw linearly at an identical velocity.

5. The method of claim 2 , wherein the step b further comprises deriving an initial temperature-rising rate from the initial temperature-rising curve, and the step c further comprises deriving a detected temperature-rising rate from the detected temperature-rising curve, in which the preload residual rates of the step d is a ratio between the detected temperature-rising rate and the initial temperature-rising rate.

6. The method of claim 5 , wherein each of the initial temperature-rising curve and the detected temperature-rising curve has an almost straight linear segment, in which the initial temperature-rising rate and the detected temperature-rising rate are slopes of the linear segments of the initial temperature-rising curve and the detected temperature-rising curve, respectively.

7. The method of claim 4 , wherein the step b further comprises deriving an initial temperature-rising rate from the initial temperature-rising curve, and the step c further comprises deriving a detected temperature-rising rate from the detected temperature-rising curve, in which the preload residual rates of the step d is a ratio between the detected temperature-rising rate and the initial temperature-rising rate.

8. The method of claim 7 , wherein each of the initial temperature-rising curve and the detected temperature-rising curve has an almost straight linear segment, in which the initial temperature-rising rate and the detected temperature-rising rate are slopes of the linear segments of the initial temperature-rising curve and the detected temperature-rising curve, respectively.

9. The method of claim 3 , wherein the nut has an outer periphery, and a receiving hole depressed from the outer periphery toward the screw for allowing the temperature sensor to be installed therein.

10. The method of claim 3 , wherein the nut has an end surface, and a receiving hole depressed from the end surface near the screw for allowing the temperature sensor to be installed therein.

11. The method of claim 1 , wherein the element on which the temperature sensor is installed has receiving hole for allowing the temperature sensor to be installed therein.

12. The method of claim 1 , wherein the temperature sensor is a thermocouple.

Assignees

• Hiwin Tech Corp

Inventors

• Tsai Meng-Shiun
• Hsieh Wen-Hsin
• Yang An-Shik
• Yuan Wei-Hsiang
• Huang Hong-Wei
• Liu Chung-Ching
• Hwang Yih-Chyun

Classifications

• F16H25/2204

  with balls · CPC title

• F16H25/2209

  with arrangements for taking up backlash · CPC title

• G01K3/10

  in respect of time, e.g. reacting only to a quick change of temperature · CPC title

• G01L1/00

  Measuring force or stress, in general (measuring force due to impact G01L5/00) · CPC title

• G01K13/08 Primary

  in rotary movement · CPC title