Description:TECHNICAL FIELD
[0001] The present invention generally relates to a bearing assembly. More particularly, the invention describes an encoder assembly for the bearing assembly.
BACKGROUND OF THE INVENTION
[0002] A bearing encoder detects the movement of the rotating shaft on which it is mounted in particular to detect the speed of the motor or the shaft, or the position or the direction of rotation of a motor. Measuring these latter parameters allows the motor to be controlled in position or speed.
[0003] The European patent EP2682758 discloses a sensor unit for measuring the angular position of a rotating element relative to a stationary element. The sensor unit comprises an encoder element attached to the rotating element that generates a magnetic field that varies depending on its angular position, and a sensing element attached to the stationary element that detects the magnetic field variations. The sensing element is supported by a sensor body that is mounted in a shielding casing attached to the stationary element. The shielding casing comprises at least one flux concentrator that deflects interfering magnetic fields away from the sensing element.
[0004] Another patent application EP2153076A1 discloses about mechanical indexing means for instrumented bearing block for precise adjustment of the relative angular position of the sensor element(s) relative to the phases of the motor stator. Even though there are many bearing encoder assembly exists, many of them have to deal with alignment issues in the following scenarios such as while assembling the sensors mechanically apart in a fixed angle or misalignment of the sensor element with continuous usage and also disturbance due to electromagnetic interference.
[0005] Therefore, there is a need for a bearing encoder assembly that can overcome the drawbacks discussed.

SUMMARY OF THE INVENTION
[0006] An object of the present invention is to provide a bearing encoder assembly. The bearing encoder assembly includes a housing that includes an encoder being rotatable with respect to an adapter to generate rotational parameter signals. The adapter includes a sensor assembly and a printed circuit board, wherein the sensor assembly includes at least three sensors that are electrically separated to sense the rotational parameter signals. The printed circuit board process the rotational parameter signals from the sensor assembly.
[0007] These and other objects of the invention herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The embodiments of the invention are illustrated in the accompanying drawings, throughout which the reference letters indicate corresponding part in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0009] Figure 1 illustrates a cross sectional view of bearing encoder assembly, in accordance with an embodiment of the invention.
[0010] Figure 2 illustrates the cross sectional view of the sensor assembly coupled to the adapter inside the housing, in accordance with an embodiment of the invention.
[0011] Figure 3 illustrates the cross section view 300 of encoder coupled to a bearing, in accordance with an embodiment of the invention.
[0012] Figure 4 illustrates the exploded view 400 of bearing encoder assembly, in accordance with an embodiment of the invention.
[0013] Figure 5 illustrates the uvw signal generated from the three hall sensors, in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.
[0015] In the specification and the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:
[0016] The singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. “Substantially” means a range of values that is known in the art to refer to a range of values that are close to, but not necessarily equal to a certain value.
[0017] Other than in the examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as modified in all instances by the term “about.” In some aspects of the current disclosure, the terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the terms are defined to be within 10%, alternatively within 5%, alternatively within 1%, or alternatively within 0.5%.
[0018] As used herein, the term “substantially” and its variations are defined as being largely but not necessarily wholly what is specified as understood by one of ordinary skill in the art, and in one non-limiting aspect substantially refers to ranges within 10%, within 5%, within 1%, or within 0.5%.
[0019] As used herein, “combinations thereof” is inclusive of one or more of the recited elements, optionally together with a like element not recited, e.g., inclusive of a combination of one or more of the named components, optionally with one or more other components not specifically named that have essentially the same function. As used herein, the term “combination” is inclusive of blends, mixtures, alloys, reaction products, and the like.
[0020] The present invention discloses a bearing encoder assembly. The bearing encoder assembly includes a housing. The housing includes an encoder being rotatable with respect to an adapter to generate rotational parameter signals. The adapter includes a sensor assembly and a printed circuit board, wherein the sensor assembly includes at least three sensors that are electrically separated to sense the rotational parameter signals. The printed circuit board is configured to process the rotational parameter signals from the sensor assembly. The encoder is engaged to a moving element and the adapter housing the sensor assembly is enclosed in the housing which is stationary and is attached to the outer ring of the bearing.
[0021] Figure 1 illustrates a cross sectional view 100 of bearing encoder assembly, in accordance with an embodiment of the invention. The bearing encoder assembly includes a housing 102. The housing 102 includes an encoder 104, wherein the encoder 104 is rotatable with respect to an adapter 106 to generate rotational parameter signals. The adapter 106 includes a sensor assembly 108 and a printed circuit board (not disclosed in the figure). The sensor assembly 108 includes at least three sensors that are electrically separated to sense the rotational parameter signals. The printed circuit board is configured to process the rotational parameter signals from the sensor assembly. The bearing encoder assembly is coupled to a bearing. The bearing includes an inner ring 110 adapted to be attached to a rotating element (not shown in the figure). The bearing also includes an outer ring 112 stationary with respect to the inner ring 110. The bearing further includes rolling elements 114 rolling interposed between the inner ring 110 and the outer ring 112. The bearing further includes a rolling element cage 116 for retaining the rolling elements 114. The rolling element cage 116 along with the rolling elements 114 is in a spaced relation between the inner ring 110 an outer ring 112. The encoder 104 is a moving member coupled to the inner ring 110 of a bearing. The encoder 104 is coupled to the inner ring 110 of the bearing to generate signals corresponding to the rotational parameters of the rotating element of the machine. The adapter 106 and the housing 102 is coupled to the outer ring 112 of the bearing. The inner ring 110 is mounted on the rotating element of the machine. In an embodiment of the present invention, the machine is a motor or a generator. According to an embodiment of the present invention, the rotating element of the machine is a shaft of the motor or the generator.
[0022] Figure 2 illustrates the cross sectional view 200 of adapter and the sensor assembly coupled to the housing, in accordance with an embodiment of the invention. The housing 202 is coupled to an adapter 204. The adapter 204 includes a sensor assembly 208. The housing 202 along with the adapter is coupled to an outer ring of the bearing.
[0023] Figure 3 illustrates the cross section view 300 of encoder coupled to a bearing. The encoder 304 is coupled to the inner ring 310 of the bearing.
[0024] Figure 4 illustrates the exploded view 400 of bearing encoder assembly, in accordance with an embodiment of the invention. The bearing encoder assembly includes a housing 402. The housing 402 includes the adapter 406 and a sensor assembly 408, the sensor assembly includes three sensors, wherein the three sensors are electrically separated by about 120 degrees. The encoder 404 is coupled to the inner ring 410 of a bearing and the housing 402 along with the adapter 406 and the sensor assembly 408 is coupled to the outer ring 412 of the bearing. The rolling elements 414 coupled to the rolling element cage 416 are interposed between the inner ring 410 and the outer ring 412. The bearing encoder assembly further includes a sealing 418 to prevent contamination by external elements such as dust, dirt, moisture and other particles that could damage the bearing and reduce its efficiency. The sealing 418 for the bearing may be one of a rubber seals, metal shields, magnetic seals or any other suitable sealing.
[0025] According to an embodiment of the present invention, the sensor assembly 108 is configured on a pole pair of the encoder. According to another embodiment of the present invention, the housing of the bearing encoder assembly is made of plastic. In yet another embodiment of the present invention, the sensor assembly is isolated from the electromagnetic interference using epoxy.
[0026] In an embodiment of the present invention, the encoder is may be made up of magnetic rubber elastomer. In an embodiment of the present invention, may be made of Hydrogenated Nitrile Butadiene Rubber (HNBR) plus sheet metal. It can be of hydrogenating nitrile butadiene rubber (NBR) plus metal or it can be any magnetic rubber elastomer.
[0027] According to an embodiment of the present invention, the number of encoder pole pairs depend on the number of pole pairs of the motor/generator pole pair. As the number of encoder pole pairs increases the resolution of data or data point increases resulting in an accurate measurement. According to an embodiment of the present invention, during the design phase of a system which uses the present invention, the number of pole pairs of the motor/generator is determined. The number of pole pairs of the motor/generator is intern determined based on the accuracy required for the measurement of rotational parameters, as the number of pole pairs on the encoder determines accuracy in measurement.
[0028] In an embodiment of the present invention, the adapter may concentrically surround the encoder and houses sensor assembly. According to an embodiment of the present invention, the sensor assembly includes three hall sensors. In an embodiment of the present invention, the three hall sensors of the sensor assembly are electrically separated by about 120 degrees apart and the sensors are mechanically placed according to the number of encoder pole pairs.
[0029] In an embodiment of the present invention, the adapter facilitates the positioning of the three hall sensors on the inner wall of the adapter which are aligned about 120 degrees from the top plane of the bearing to generate an output signal and connected with a wire for the output. According to an embodiment of the present invention, the three hall sensors are placed such that the angle between the respective output from the hall sensors is about 120 degrees electrically offset from each other. The output angle is referred to as the electrical angle which is the same as the electrical output. However, the mechanical angle between the three hall sensors may differ respective to magnetic encoder pole pairs.
[0030] Figure 5 illustrates the U V and W signal generated from the three hall sensors, in accordance with an embodiment of the invention. It illustrates that the signal U V and W are about 120 degrees apart, where the hall sensors hall 1, hall 2 and hall 3 provides the U V W signals and the three hall sensors are electrically 120 degrees apart and the three sensors need not be mechanically 120 degrees apart.
[0031] According to an embodiment of the present invention, the sensor assembly is configured based on the motor pole pair. In an embodiment of the present invention, the mechanical separation of sensors is a function of pole configuration of the encoder, which is directly dependent on the motor pole pair. In an example embodiment the pole configuration relationship is calculated using the following formula:
2/(Number of poles)×120°
[0032] The advantage of this invention is that the sensors need not be placed 120 degrees mechanically apart thus indexing means are not required to match the encoder with pole of motor/generator. As the encoder receives 120 degrees apart signals without the need to place the sensors mechanically 120 degrees apart helps in reducing the alignment issues of the encoder. The sensor assembly is connected to a PCB having processing circuit to retrieve data sensed from the sensors.
[0033] According to an embodiment of the present invention, the encoder along with the housing having the adapter and the sensor assembly may be integrated with any bearings without any modification on bearing level. Only the plastic housing along with the adapter needs to be developed for the sensor placement. In yet another embodiment of the present invention, the encoder along with the housing having the adapter and the sensor assembly may be retrofitted with the bearing.
[0034] In an embodiment of the present invention, the bearing is a ball bearing.
[0035] According to an embodiment of the present invention, when the shaft connected to the inner ring of bearing rotates the encoder coupled to the inner ring also rotates, this change in magnetic field generated by rotation of encoder is captured by the hall sensors that are positioned 120 degree electrically apart, The hall sensor in turn generates a U, V, W signal that can be processed by the processing circuit connected to printed circuit board (PCB) to retrieve the rotational parameters of the machine like speed, position etc.
[0036] In an example embodiment, suppose there are 16 magnet poles (8 north poles and 8 south poles) in a system. To obtain about 120 electrical degrees separation between the Hall Sensors from the 16-pole encoder, the Hall sensor's position can be placed so that they are mechanically ±15 degrees.
(2/16(poles)) *120=±15 degrees (Mechanically)
[0037] According to an embodiment, the present invention may be implemented for any rotating electrical machine having a motor and/or generator operating mode, such as for example a motor vehicle alternator in starter mode. The sensor bearing could in particular be associated with an electric motor used in an electric or hybrid vehicle, or even be used to power any load, which needs position information to be taken from a rotating shaft independent of it.
ADVANTAGES
[0038] The technical advantages brought in by the present invention are as follows;
1. The first advantage of the is that the present invention acts as a commutation system for the motor directly and there is no misalignment and failure on the sensor due to electromagnetic compatibility (EMC)/Electromagnetic interference (EMI). But in this electromagnetic compatibility (EMC)/electromagnetic interference (EMI) will not directly hit the sensor because the sensor is inside the bearings with epoxy.
2. At very high motor speeds, it is difficult to differentiate the different transitions when back electromotive force is used. Using the present invention if the motor moves at very high speeds to alleviate this issue.
3. Rotational driver units have a simple protocol with simplified UVW protocol which can be used to drive the motor
4. The encoder assembly is having high efficiency, reliability and long lifetime along with compact size so that it can support a wide range of motors
[0039] While considerable emphasis has been placed herein on the components and component parts of the various embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the embodiments without departing from the scope and spirit of the invention. These and other changes in the various embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
, C , C , Claims:
CLAIMS
We claim:
1. A bearing encoder assembly comprises:
? a housing 102 comprising:
? an encoder 104 being rotatable with respect to an adapter 106 to generate rotational parameter signals;
? the adapter 106 comprising a sensor assembly 108 and a printed circuit board, wherein the sensor assembly 108 comprising at least three sensors that are electrically separated to sense the rotational parameter signals and the printed circuit board is configured to process the rotational parameter signals from the sensor assembly.
2. The bearing encoder assembly as of claim 1 wherein the encoder 104 is coupled to an outer ring of a bearing assembly 112.
3. The bearing encoder assembly as of claim 1 wherein the sensor assembly 108 is configured on a pole pair of the encoder 104.
4. The bearing encoder assembly as of claim 1 wherein the housing 102 is made of plastic.
5. The bearing encoder assembly as of claim 1 wherein the sensor assembly 108 is isolated from the electromagnetic interference using epoxy.
Dated this 1st day of December 2023
Signature:
Athira Ashaletha
Patent Agent (INPA/2423)
TekIP® Knowledge Consulting Pvt. Ltd.,
No. 89, HL216/2, Zareen Heights,
Nagavarapalya, C.V.Raman Nagar PO,
Bangalore - 560093, India
Email: docketing@tekip.com