Wheel bearing with sensor

Patent metadata

Field	Value
Publication number	US-9518609-B2
Application number	US-201113821772-A
Country	US
Kind code	B2
Filing date	Sep 2, 2011
Priority date	Sep 10, 2010
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A sensor equipped wheel support bearing assembly, in which a continuous estimated load can be obtained depending on various inputted load conditions is provided. The sensor equipped wheel support bearing assembly includes a sensor unit provided in a stationary member, and a load estimating unit. The load estimating unit includes a load estimation calculating section for calculating the load using an estimation calculating equation, an evaluation value calculation section for calculating an evaluation value, which provides a parameter switching index in the estimation calculating equation, from sensor output signals, and a parameter switching section for switching the parameter based on a comparison result of the evaluation value with a threshold value. The load estimation calculating section includes a calculation correcting block for correcting the calculation result on both sides of the threshold value within a predetermined evaluation value region containing the threshold value.

First claim

What is claimed:

1. A sensor equipped wheel support bearing assembly comprising:
a wheel support bearing for rotatably supporting a vehicle wheel relative to a vehicle body structure, the bearing comprising an outer member having an inner periphery formed with a plurality of rolling surfaces, an inner member having an outer periphery formed with rolling surfaces that face the respective rolling surfaces in the outer member, and a plurality of rows of rolling elements interposed between the rolling surfaces in the outer member and the rolling surfaces in the inner member;
a plurality of load detecting sensor units provided in one of the outer member and the inner member that serves as a stationary member, each of the sensor units including a strain generating member, having two or more contact fixing segments to be fixed to the stationary member in contact therewith, and one or more sensors fitted to the strain generating member for detecting a strain occurring in the strain generating member, the sensor units including upper, lower, right and left sensor units disposed at upper, lower, right and left surface areas of the outer diametric surface of the stationary member, respectively, which correspond respectively to top, bottom, right surface and left surface locations relative to a tire tread surface, in 90° phase difference relative to each other and in equidistantly spaced relation to each other;
a load estimating unit including a processor configured to estimate a load acting on the vehicle wheel from an output signal of the sensor in each of the sensor units,
the load estimating unit including a load estimation calculating section for calculating the load acting on the wheel support bearing by applying the output of the sensor in each of the sensor units to an estimation calculating equation, an evaluation value calculation section for calculating one or more evaluation value to be used as an index for switching a parameter in the estimation calculating equation, from the output signal of the sensor in each of the sensor units, and a parameter switching section for comparing the evaluation value with a predetermined threshold value to switch the parameter in the estimation calculating equation in dependence on a result of such comparison;
the load estimation calculating section including a calculation correcting block for correcting a result of calculation by combining two load estimation results calculated by the estimation calculating equation with the use of the parameters within respective evaluation value regions on both sides of the threshold value in the event that the evaluation value is within a predetermined region containing the threshold value,
wherein the evaluation value calculation section calculates as the evaluation value a combination of two or more evaluation values, the two or more evaluation values indicative of a travelling speed of an automotive vehicle, a difference between amplitude values of output signals of the upper and lower sensor units, and a difference between amplitude values of output signals of the right and left sensor units.

2. The sensor equipped wheel support bearing assembly as claimed in claim 1 , wherein the load estimating unit is operable to estimate loads in three directions, including two radially acting loads acting in a vertical direction and a bilateral direction, which loads acts on the wheel support bearing, and one axially acting load acting in an axial direction, from output signals of the sensor units.

3. The sensor equipped wheel support bearing assembly as claimed in claim 1 , wherein the load estimating unit further includes a direction determining section for determining the direction of the axially acting load by utilizing the difference between amplitude values of the respective output signals of sensors of the sensor units disposed at top and bottom positions relative to the tire tread surface in face to face relation to each other and in which the parameter switching section includes a direction correspondent command block for switching the parameter of the estimation calculating equation in the load estimation calculating unit in dependence on the result of determination performed by the direction determining section.

4. The sensor equipped wheel support bearing assembly as claimed in claim 1 , wherein the load estimating unit includes a preprocessing section for calculating the average value and the amplitude value of the output signal of each of the sensors in each of the sensor units within a predetermined length of time and the estimation calculating equation in the load estimation calculating section calculates and processes the load with the use of one of only the average value and the amplitude value or with the use of both of the average value and the amplitude value.

5. The sensor equipped wheel support bearing assembly as claimed in claim 4 , wherein each of the sensor units includes three or more contact fixing segments and two sensors, the sensors being fitted between the neighboring first and second contact fixing segments and between the neighboring second and third contact fixing segments, and wherein the distance of spacing between the neighboring contact fixing segments or the neighboring sensors in a direction circumferentially of the stationary member is chosen to ½+n times of a pitch of arrangement of the rolling elements, where n represents an integer, and the load estimating unit makes use of the sum of the output signals of the two sensors as an average value.

6. A sensor equipped wheel support bearing assembly comprising:
a wheel support bearing for rotatably supporting a vehicle wheel relative to a vehicle body structure, the bearing comprising an outer member having an inner periphery formed with a plurality of rolling surfaces, an inner member having an outer periphery formed with rolling surfaces that faces the respective rolling surfaces in the outer member, and a plurality of rows of rolling elements interposed between the rolling surfaces in the outer member and the rolling surfaces in the inner member;
a plurality of load detecting sensor units provided in one of the outer member and the inner member that serves as a stationary member, each of the sensor units including a strain generating member, having two or more contact fixing segments to be fixed to the stationary member in contact therewith, and one or more sensors fitted to the strain generating member for detecting a strain occurring in the strain generating member, the sensor units including upper, lower, right and left sensor units disposed at upper, lower, right and left surface areas of the outer diametric surface of the stationary member, respectively, which correspond respectively to top, bottom, right surface and left surface locations relative to a tire tread surface, in 90° phase difference relative to each other and in equidistantly spaced relation to each other;
a load estimating unit including a processor configured to estimate a load acting on the vehicle wheel from an output signal of the sensor in each of the sensor units,
the load estimating unit including a load estimation calculating section for calculating the load acting on the wheel support bearing by applying the output of the sensor in each of the sensor units to an estimation calculating equation, an evaluation value output section for outputting one or more evaluation value to be used as an index for switching a parameter in the estimation calculating equation, and a parameter switching section for comparing the evaluation value with a predetermined threshold value to switch the parameter in the estimation calculating equation in dependence on a result of such comparison, the threshold value having a hysteresis set thereto,
wherein the evaluation value output section calculates a

Assignees

• Akiyama Ayumi
• Takahashi Toru
• Nishikawa Kentarou
• Norimatsu Takayuki
• Ntn Toyo Bearing Co Ltd

Inventors

• Akiyama Ayumi
• Takahashi Toru
• Nishikawa Kentarou
• Norimatsu Takayuki

Classifications

• F16C41/00 Primary

  Other accessories, {e.g. devices integrated in the bearing not relating to the bearing function as such} · CPC title

• F16C19/186

  with three raceways provided integrally on parts other than race rings, e.g. third generation hubs · CPC title

• G01L5/0019

  by using strain gages, piezoelectric, piezo-resistive or other ohmic-resistance based sensors · CPC title

• F16C19/525

  related to temperature and heat, e.g. insulation · CPC title

• F16C2326/02

  Wheel hubs or castors · CPC title