Sensor-bearing unit and apparatus comprising such an unit

Patent metadata

Field	Value
Publication number	US-9353796-B2
Application number	US-201214403286-A
Country	US
Kind code	B2
Filing date	May 22, 2012
Priority date	May 22, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A sensor-bearing unit, adapted for implementation in an oil lubricated environment and comprising: a bearing including at least one rotating ring movable in rotation around a central axis, and a detection device for tracking the rotation of the rotating ring. The detection device is locked to the bearing and includes at least one target and at least one sensor associated with the target. At least one axial side of the bearing includes a passage opened along an axial direction parallel to the central axis and allowing an oil flow through the bearing. The detection device includes an air gap defined radially to the central axis between a maximum outer radius of the target and a minimum inner radius of the sensor.

First claim

The invention claimed is:

1. An apparatus comprising a sensor-bearing unit adapted for implementation in an oil lubricated environment, comprising:
an apparatus housing defining a recess therein with a recess sidewall;
the sensor-bearing unit, comprising
a bearing having an inner ring and an outer ring positioned about a central axis and a plurality of rolling elements therebetween, the outer ring having an axially extending outer surface, the bearing is positioned within the recess of the apparatus housing such that the recess sidewall entirely covers and abuts the axially extending outer surface of the outer ring;
a bracket positioned along and contacting a radially extending axial side of the outer ring;
a sensor holder attached to a side of the bracket opposite from the radially extending axial side of the outer ring, the sensor holder not contacting the outer ring;
a sensor housing secured to the sensor holder and not contacting the outer ring, the sensor housing extending radially inwardly past the outer ring;
a detection cell disposed in and enclosed by the sensor housing;
a magnet secured to the inner ring;

wherein an axial side of the bearing adjacent the sensor housing comprises a passage opened along an axial direction parallel to the central axis and allowing an oil flow through the bearing, the passage including an air gap defined radially to the central axis between a maximum outer radius of the magnet and a minimum inner radius of the sensor housing.

2. The sensor-bearing unit according to claim 1 , wherein an opposite axial side of the bearing includes a second passage opened along the axial direction parallel to the central axis and allowing a second oil flow through the bearing.

3. The sensor-bearing unit according to claim 1 , wherein the passage comprises a first portion for oil entry inside the bearing and a second portion for oil outflow outside the bearing.

4. The sensor-bearing unit according to claim 1 , wherein a sealing member is located on the axial side of the bearing between the plurality of rolling elements and the passage.

5. The sensor-bearing unit according to claim 1 , wherein the minimum inner radius of the sensor housing extending towards the central axis is greater than the maximum outer radius of the magnet around the central axis.

6. The sensor-bearing unit according to claim 1 , wherein the magnet and a sensor form a detection device and the magnet guides the oil flow along the axial direction between the magnet and the sensor housing.

7. The sensor-bearing unit according to claim 1 , wherein the magnet and a sensor form a detection device with radial reading.

8. The sensor-bearing unit according to claim 1 , further comprising a sensor including an electronic card and the detection cell connected to the electronic card.

9. The sensor-bearing unit according to claim 1 , wherein the maximum outer radius of the magnet defined radially to the central axis is comprised between 95 % and 105 % of a maximum radius of the inner ring of the bearing.

10. The apparatus according to claim 1 , wherein the apparatus includes a rotating shaft and wherein the inner ring of the sensor-bearing unit is mounted on the shaft and the outer ring is mounted in the apparatus housing.

11. The apparatus according to claim 1 , wherein the apparatus is an electric motor comprising a rotor locked in rotation with a shaft and a stator fixed to the apparatus housing.

12. The apparatus according to claim 1 , wherein the apparatus includes an inner chamber at least partially filled with an oil bath.

13. The apparatus according to claim 1 , wherein the passage is free of any shield or seal between the air gap and at least one of the plurality of rolling elements and a cage configured to circumferentially space the plurality of rolling elements such that a particle traveling in the axial direction from the air gap towards the plurality of rolling elements will not contact any element before reaching the at least one of the plurality of rolling elements and the cage.

Assignees

• Blokland Susanne
• Maze Pierrick
• Sausset Vincent
• Skf Ab

Inventors

• Blokland Susanne
• Maze Pierrick
• Sausset Vincent

Classifications

• F16C41/007

  Encoders, e.g. parts with a plurality of alternating magnetic poles · CPC title

• F16C33/6685

  Details of collecting or draining, e.g. returning the liquid to a sump · CPC title

• G01D11/02

  Bearings or suspensions for moving parts · CPC title

• F16C33/6666

  from an oil bath in the bearing housing, e.g. by an oil ring or centrifugal disc · CPC title

• F16C19/06

  with a single row or balls · CPC title