Wheel bearing unit for mounting vehicle wheel

Abstract

The invention relates to a wheel bearing unit (1) for mounting a vehicle wheel, comprising a wheel hub (2) and a rolling contact bearing unit (3), the rolling contact bearing unit (3) comprising at least two rows of rolling contact bodies (4), which are arranged between an outer ring (5) and the wheel hub (2) or an inner ring (6), the outer ring (5) has at least two fixing points (7) for fixing the outer ring (5) to the wheel carrier (8), and wherein a measuring device (9) is axially arranged between the outer ring (5) and the wheel carrier (8).

Description

Technical Field

[0001] The present invention relates to a wheel bearing unit for mounting a vehicle wheel, the wheel bearing unit having a wheel hub and a rolling contact bearing unit, wherein the rolling contact bearing unit includes at least two rows of rolling contact bodies disposed between an outer ring and a wheel hub or an inner ring, wherein the outer ring has at least two fixing points for fixing the outer ring to a wheel carrier. Background Technology

[0002] Currently, various systems for autonomous driving are being developed for commercial vehicles such as trucks, trailers, and buses. Distance sensors such as radar, lasers, ultrasonic sensors, and cameras are primarily used to control these systems. In this context, the demand for additional sensor data is expected to increase even further in the future. Wheel forces are of particular interest, but vibration and temperature should also be measured.

[0003] In particular, for autonomous driving, it will be necessary to determine the forces acting on the wheel bearings as accurately as possible, as close as possible to the vehicle's wheels. Currently, known systems in the prior art cannot provide very precise data due to their layout and design.

[0004] Publication DE 10 2018 111 841 A1 describes a wheel hub for mounting a vehicle wheel on an axle, wherein a measuring ring is provided for measuring forces on the wheel bearing. The measuring ring is axially mounted in front of an inner ring and has at least one measuring device for strain and / or compression measurements. Summary of the Invention

[0005] The object of this invention is to provide a wheel bearing unit that can measure the wheel forces acting on a wheel as accurately and cost-effectively as possible. Furthermore, the object of this invention is to provide a wheel bearing with a long service life and low friction.

[0006] According to the present invention, this objective is achieved by a wheel bearing unit having the features of claim 1. Preferred embodiments of the invention are specifically described in the dependent claims and the following description, and each of the preferred embodiments may individually or in combination present an aspect of the invention.

[0007] The wheel bearing unit for mounting a wheel according to the present invention comprises a wheel hub and a rolling contact bearing unit, wherein the rolling contact bearing unit includes at least two rows of rolling contact bodies disposed between an outer ring and a wheel hub or an inner ring, wherein the outer ring has at least two fixing points for fixing the outer ring to a wheel carrier. A measuring device is also axially disposed between the outer ring and the wheel carrier.

[0008] This measuring device can measure the actual force at a point due to the axial arrangement between the outer ring and the wheel bearing. This allows for very precise measurement of the forces present in the wheel bearing.

[0009] Preferably, the measuring device is designed as an annular disk with at least two fixed points. Therefore, the measuring device comprises an annular disk with an annular surface and at least two fixed points. Preferably, the profile of the measuring device corresponds to the profile of the contact surface on the outer ring. The measuring device is preferably rested on the fixed points of the outer ring only at its fixed points (particularly in a planar manner).

[0010] In one embodiment, the measuring device and the outer ring each have multiple fixing points, particularly four fixing points each. Therefore, both the measuring device and the outer ring specifically have four fixing points, for example, in the form of holes, as screw-in points. In this respect, the fixing points can be distributed around the circumference at regular or irregular intervals. However, it is particularly preferred that the fixing points are spaced differently from each other.

[0011] In a preferred embodiment, the measuring device has at least one measuring point, and more preferably, multiple measuring points. The measuring points can be arranged in a circular distribution around the annular disk of the measuring device at regular or irregular intervals. Preferably, at least one measuring point is arranged between a pair of fixed points, and more preferably, two measuring points are arranged.

[0012] Regarding the manufacturing of the measuring device, the annular surface of the disc is exposed first. At this point, the mounting points of the measuring device have a greater thickness than the annular surface. This allows the measuring points to be applied within the annular area. After the measuring points have been attached, the exposed annular surface is completely sealed with a substrate to form a complete annular surface. This helps protect the measuring points and seals the contact surfaces between the wheel bearing and the wheel load-bearing components to prevent the ingress of dust and water. The measuring device is also connected to an electronic system that converts the measured signals into vehicle-specific force values ​​and feeds them to the vehicle's ECU.

[0013] The measurement point can be, for example, a coating such as a Sensortect. Using this thin-film sensor technology, the function of the strain gauge is realized as a direct coating on the corresponding component.

[0014] Alternatively, the measuring point can be designed as a strain gauge. A strain gauge is a measuring device used to detect tensile and compressive deformation. The resistance of a strain gauge changes even with slight deformation, and it is therefore used as a strain sensor. Generally, they are glued to the component that deforms least under load using a special adhesive. This deformation (strain) then causes a change in the resistance of the strain gauge.

[0015] In a preferred embodiment, in addition to the measurement points, the measuring device is also equipped with a sensor, which is preferably an acceleration sensor and / or a temperature sensor. Attached Figure Description

[0016] In the following description, the invention will be illustrated by way of example using preferred exemplary embodiments with reference to the accompanying drawings, wherein the features presented below may individually or in combination represent aspects of the invention. In the drawings: Figure 1 A three-dimensional view of the wheel bearing unit is shown. Figure 2 A cross-sectional view of the measuring device according to the present invention is shown. Figure 3 It shows that it has the following characteristics: Figure 2 The cross-sectional view of the wheel bearing unit of the measuring device is shown in the figure. Detailed Implementation

[0017] Figure 1 A three-dimensional view of the main components of wheel bearing unit 1 is shown. Wheel bearing unit 1 has a wheel hub 2 and an outer ring 5. A rolling contact bearing unit 3 with a rolling contact body 4 is disposed between the wheel hub 2 and the outer ring 5. The wheel hub 2 has a flange with a screw-in point for installation. Figure 1 In the embodiment shown, the wheel bearing unit 1 has spur teeth that are axially applied at the ends to the roller rivet collar of the wheel hub 2. The spur teeth can engage with complementary spur teeth of the joint bell-shaped cover (not shown). However, in principle, radial teeth or non-driven wheel bearing units are also conceivable.

[0018] The outer ring 5 has at least two, preferably four, fixing points 7. Figure 1 The shaded area on the outer ring shown represents the surface that typically contacts the wheel bearing element (not shown here). The wheel bearing unit 1 or outer ring 5 is secured to the wheel bearing element via fixing point 7. Fixing point 7 is typically designed as a screw-in point in the form of a hole.

[0019] Figure 2A measuring device 9 according to the invention is shown. The measuring device 9 is designed as an annular disk and has at least two, but preferably multiple, fixing points 9a. The fixing points 9a of the measuring device 9 have holes for fixing to a wheel bearing (not shown). The fixing points 9a protrude radially R relative to the annular surface. The annular disk of the measuring device 9 is provided with at least one, preferably multiple measuring points 10. The measuring points 10 can be a coating, such as a Sensortect coating, or a strain gauge. The measuring points 10 are arranged in a circumferential distribution around the measuring device 9. The measuring points 10 are located on the surface facing the wheel bearing, i.e., facing the outer ring 5, in the installed state. Therefore, the measuring points 10 are axially positioned between the outer ring 5 and the wheel bearing 8. Particularly preferably, the measuring points 10 are symmetrically arranged about the central axis M of the measuring device 9. Furthermore, an additional sensor 11, designed as, for example, an acceleration sensor and / or a temperature sensor, can be provided radially outward from the annular surface of the measuring device 9.

[0020] Figure 3 A wheel bearing unit 1 with a built-in measuring device 9 is shown. An inner ring 6 is pressed against a wheel hub 2. Preferably, at least two rows of rolling contact bodies 4 of the rolling contact bearing unit 3 extend between the wheel hub 2 and the outer ring 5, or between the inner ring 6 and the outer ring 5. The measuring device 9 rests axially against the outer ring 5 in a planar manner on the wheel side. The measuring device 9 rests axially against the wheel carrier 8 in a planar manner on the drive side, at least in the region of the fixed point 9a. Particularly preferably, the measuring device 9 rests against the wheel carrier 8 only in at least a portion of the region of the fixed point 9a. Therefore, the surface of the annular disc of the measuring device 9 rests neither against the outer ring 5 nor against the wheel carrier 8. Compared to the prior art, the significantly smaller contact surface greatly further reduces the friction of the wheel bearing.

[0021] List of reference numerals 1 Wheel bearing unit 2. Wheel hub 3 Rolling contact bearing unit 4. Rolling contact body 5 Outer ring 6 Inner Circle 7 Fixed points 8-wheel load-bearing components 9. Measuring device 9a Fixed point 10 Measurement Points 11 Sensors Axial direction R represents the radial direction.

Claims

1. A wheel bearing unit (1) for mounting a vehicle wheel, the wheel bearing unit having a wheel hub (2) and a rolling contact bearing unit (3), wherein, The rolling contact bearing unit (3) includes at least two rows of rolling contact bodies (4), which are disposed between the outer ring (5) and the wheel hub (2) or the inner ring (6). The outer ring (5) has at least two fixing points (7) for fixing the outer ring (5) to the wheel bearing member (8). The outer ring (5) is characterized in that a measuring device (9) is axially disposed between the outer ring (5) and the wheel bearing member (8).

2. The wheel bearing unit (1) according to claim 1, characterized in that, The measuring device (9) is designed as an annular disk with at least two fixed points (9a).

3. The wheel bearing unit (1) according to claim 2, characterized in that, The measuring device (9) and the outer ring (5) each have multiple fixed points (7, 9a), and in particular, each has four fixed points (7, 9a).

4. The wheel bearing unit (1) according to any one of the preceding claims, characterized in that, The measuring device (9) has at least one measuring point (10), and particularly preferably has multiple measuring points (10).

5. The wheel bearing unit (1) according to claim 4, characterized in that, The at least one measurement point (10) is formed by a coating, particularly a Sensotect coating.

6. The wheel bearing unit (1) according to claim 4, characterized in that, The at least one measurement point (10) is formed by a strain gauge.

7. The wheel bearing unit (1) according to any one of claims 4 to 6, characterized in that, In addition to the measurement point (10), the measuring device (9) also has a sensor (11), which is preferably an acceleration sensor and / or a temperature sensor.

8. The wheel bearing unit (1) according to any one of claims 4 to 7, characterized in that, The surface of the measuring device (9) on which the measuring point (10) is formed is sealed.

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