Sensor bearing assembly and associated sensor carrier and pulley unit

Abstract

The sensor bearing arrangement comprises a sensor body (11), a bearing (12) with an inner ring and an outer ring centered on an axis (X-X'), a pulse ring attached to the outer ring, and a sensor device (16) for detecting rotational parameters of the pulse ring, comprising at least one sensor element supported by the sensor body (11) and interacting with the pulse ring. The sensor body (11) is provided with an inner through-hole (26) having a non-circular cross-section (28).

Description

The present invention relates to a sensor bearing assembly comprising a bearing, a impulse ring, a sensor device and a sensor body supporting the sensor device.The present invention also relates to a sensor carrier and pulley unit connected to such a sensor bearing assembly.The present invention relates to a sensor storage arrangement, particularly suitable for lifting systems used for autonomous forklifts, for example.Autonomous forklifts are generally used for transporting loads by lifting them with a fork. The fork is driven by a motor, a pulley system and a flexible drive which transmits the power of the motor to the pulley.In general, autonomous forklifts measure the height of the fork with respect to the ground by means of at least one telemetry unit which is separately attached to a stationary part of the forklift.The installation of such a telemetry is delicate, since great care must be taken to ensure accurate positioning for reliable measurement. Moreover, the measurement accuracy may vary depending on the environmental operating conditions (such as bright light, dust particles, etc.), and the reliability of the measurement may be prone to errors if the carrier of the telemetry does not reflect well.Moreover, such a configuration does not allow a compact measuring device and the telemetry unit may be subject to accidental impacts.An object of the present invention is to overcome these disadvantages.The invention relates to a sensor bearing assembly comprising a sensor body, a bearing comprising an inner ring and an outer ring centered on an axis, the inner ring being fixed to the sensor body, a pulse ring fixed to the outer ring of the bearing, and a sensor device for detecting rotation parameters of the pulse ring comprising at least one sensor element supported by the sensor body and cooperating with the pulse ring.The sensor body is provided with an inner through hole having a non-circular cross section.Such a sensor bearing arrangement optimizes compactness and enables enhanced integration. The shape of the sensor body makes it possible to obtain an integrated anti-rotation means.For example, the sensor body includes a central ring that limits an axial length of the sensor body and a base that radially protrudes from the central ring, wherein the inner ring of the bearing axially abuts the base.Advantageously, the base and the central ring form a planar side surface of the sensor body. Such a configuration contributes to optimization of compactness.Preferably, the inner through hole of the sensor body comprises two opposing parallel flat surfaces. Such opposing parallel flat surfaces provide anti-rotation means for blocking rotation of the sensor body with respect to a support.For example, the impulse ring comprises a radial portion and an axial portion, the radial portion being fixed to the outer ring of the bearing and protruding radially inward with respect to the outer ring, the axial portion protruding axially into a chamber provided at the base of the sensor body. Such a configuration contributes to optimization of compactness.Preferably, the axial portion is provided with a plurality of detection targets.In an embodiment, the detection targets of the plurality of detection targets are evenly distributed over a perimeter of the axial portion.Advantageously, the sensor device is provided with a cable extending radially outwards with respect to the base and at a predetermined angle. Such a configuration reduces the risk of accidental shock to the cable.In another aspect, the invention relates to a sensor support comprising a support having two opposing arms and a sensor bearing arrangement as specified above. The sensor bearing assembly is mounted on the bracket with a pin inserted into the inner through hole of the sensor body and two opposing holes provided on each of the arms. The pin has a cross-section corresponding to the cross-section of the inner through-hole of the sensor body and the cross-section of each of the two opposing holes, respectively, to block relative rotation between the sensor bearing assembly and the carrier.In another aspect, the invention relates to a pulley unit comprising a sensor carrier as specified above, a pulley fixed to the outer ring of the bearing of the sensor bearing assembly, and a flexible drive fixed to the pulley.The present invention and its advantages will become more fully understood by a study of the detailed description of a specific embodiment, given by way of non-limiting example and illustrated by the accompanying drawings, in which:FIG. 1 is a perspective view of a sensor bearing assembly according to an example of the invention,FIG. 2 is a cross-section along the axis II-II of FIG. 1 ,FIG. 3 is a perspective view of a pulley unit according to an example of the invention including the sensor bearing assembly of FIG. 1 ; andFIG. 4 is an exploded view of the pulley unit of FIG. 3.The sensor storage arrangement 10 illustrated in FIG. 1 is configured to equip an autonomous forklift.As shown in FIGS. 1 and 2, the sensor bearing assembly 10 includes a sensor body 11, a bearing 12, and a pulse ring 14 (visible in FIG. 2 ), and a sensor device 16 supported by the sensor body 11. The bearing 12 and the impulse ring 14 form a sensor bearing unit. The sensor device 16 detects rotation parameters of the impulse ring 14 and comprises at least one sensor element 17 which is carried by the sensor body 11 and interacts with the impulse ring 14.The bearing 12 includes an inner ring 18 and an outer ring 20. The outer ring 20 radially surrounds the inner ring 18. The inner and outer rings 18, 20 are made of steel.The impulse ring 14 is fastened to the outer ring 20 of the bearing 12 and the sensor device 16 is fastened to the sensor body 11.In the example shown, the bearing 12 also includes two rows of rolling elements 22, provided here in the form of balls, arranged between raceways (not numbered) formed on the inner and outer rings 18, 20.The bearing 12 also includes a cage (not numbered) to maintain the uniform circumferential spacing of the rollers 22. The bearing 12 further includes a seal 23 radially disposed between the inner and outer rings 18, 20 to define a closed space in which the rolling elements 22 are disposed.The outer ring 20 is provided with an inner cylindrical surface or bore 20a and an outer cylindrical surface 20b radially facing the bore 20a. In the example shown, toroidal circular raceways for the rolling elements 22 are formed from the bore 20a, the raceways being directed radially inwardly. A groove (not numbered) is also formed on the bore 20a in which the seal 23 is fixed.In this example, the outer ring 20 is also provided with two opposite radial side surfaces 20 c, 20 d, which axially delimit the outer surface 20 bof the ring.The outer ring 20 is provided with a recess 24 that extends axially inward from the side surface 20 c. The recess 24 and the side surface 20d delimit the bore 20a of the ring. The recess 24 is provided with a groove 24a.Similar to the outer ring 20, the inner ring 18 is provided with an inner cylindrical surface or bore 18a and an outer cylindrical surface 18b radially facing the bore 18a. In the example shown, toroidal circular raceways for the rolling bodies 22 are formed from the outer surface 18 b, the raceway being directed radially outwards.The inner ring 18 is also provided with two opposite radial lateral surfaces 18c, 18d which axially delimit the bore 18a and the outer surface 18b of the ring.As clearly seen in FIG. 1, the sensor body 11 is provided with an inner through hole 26 having a non-circular cross section 28. The through hole 26 includes two opposed parallel flat surfaces 28a, 28b and two opposed concave surfaces 28c, 28d connected to the flat surfaces 28a, 28b.The sensor body 11 includes a central ring 30 and a base 32, and the base 32 and the central ring 30 form a planar side surface 11 bof the sensor body 11.The central ring 30 extends axially and defines the axial length of the sensor body 11. the central ring 30 is provided with an inner surface or bore 30a and a cylindrical outer surface 30b radially opposite the bore 30a. The bore 30a forms the through hole 26 of the sensor body 11.The base 32 projects radially from the central ring 30, forming a shoulder 34.The inner ring 18 is fixed on the sensor body 11. Preferably, bore 18a is secured to outer cylindrical surface 30b and side surface 18c axially abuts shoulder 34.As mentioned above, in the disclosed example, the impulse ring 14 is fixed to the outer ring 20. The impulse ring 14 comprises a radial section 14 aand an axial section 14 b. The radial portion 14 ais fixed to the outer ring 20, for example, by press-fitting in the recess 24 and the groove 24 a. The radial portion 14 aprotrudes radially inward with respect to the outer ring 20. The axial portion 14b axially protrudes into a chamber 36 provided on the base 32 of the sensor body 11.The axial portion 14 bof the impulse ring 14 is provided with a plurality of detection targets 14 cradially facing the sensor elements 17. Preferably, the detection targets 14 cof the plurality of detection targets 14 care uniformly distributed over a circumference of the axial portion 14 b.The impulse ring 14 and the sensor elements 17 may use any suitable technology, such as induction technology, optical technology or magnetic technology. In the case of magnetic technology, the impulse ring 14 may comprise alternating north and south poles and the sensor elements 17 may comprise Hall effect sensors.Preferably, the sensor device 16 comprises a sensor housing 16 athat supports and protects the sensor elements 17. The sensor device 16 further includes a cable 16b supported by the sensor housing 16a and including electrical wires (not shown). The cable 16b extends radially outward with respect to the base 32 and at a predetermined angle.As shown in FIG. 3, the sensor bearing assembly 10 is particularly adapted for use in a pulley unit 36, and more generally in a sensor carrier 38.Here, the sensor support 38 includes a support 40 having two opposing arms 42 a, 42 band a sensor bearing assembly 10 as previously described.The sensor bearing assembly 10 is fixed to the bracket 40 with a pin 44 inserted into the through hole 26 of the sensor body 11 and two opposing holes 43 a, 43 bprovided on each of the arms 42 a, 42 b(FIG. 4 ). The cross section 43 cof each of the two holes 43 a, 43 bcorresponds to the cross section 28 of the through hole 26 of the sensor body 11.The pin 44 has a cross section 44 athat respectively corresponds to the cross section 28 of the through hole of the sensor body 11 and the cross section 43 cof each of the two holes 43 a, 43 bto block relative rotation between the sensor bearing assembly 10 and the carrier 40.In the illustrated example, the pulley unit 36 includes the sensor carrier 38, a pulley 46, and a flexible drive 48. The pulley 46 is driven by a flexible drive 48 mounted on the pulley 46. Here, the flexible drive 48 is a chain drive. Alternatively, the flexible drive 48 may be a belt, cable, or cable.In the illustrated examples, the sensor bearing assembly is provided with a rolling bearing that includes two rows of rolling elements. Alternatively, the rolling bearing can comprise a different number of rows, for example one or at least three rows of rolling bodies. In the examples shown, the rolling elements are balls. Alternatively, the rolling bearing may comprise other types of rolling elements, for example rollers. In another variant, the rolling bearing can also be provided with a plain bearing which has no rolling bodies.

Claims

Sensor bearing assembly (10) comprising: - a sensor body (11), - a bearing (12) comprising an inner ring (18) and an outer ring (20) centered on an axis (X-X'), said inner ring (18) being fixed to said sensor body (11), - a pulse ring (14) fixed to said outer ring (20) of said bearing (12), and - a sensor device (16) for detecting rotation parameters of said pulse ring (14) comprising at least one sensor element (17) carried by said sensor body (11) and cooperating with said pulse ring (14), characterized in that said sensor body (11) is provided with an inner through hole (26) having a non-circular cross section (28).The sensor bearing assembly of claim 1, wherein the sensor body (11) comprises a central ring (30) limiting an axial length of the sensor body (11) and a base (32) radially protruding from the central ring (30), wherein the inner ring (18) of the bearing axially abuts the base (32).The sensor bearing assembly according to claim 2, wherein the base (32) and the central ring (30) form a planar side surface (11b) of the sensor body (11).The sensor bearing assembly according to any one of claims 1 to 3, wherein the inner through hole (26) of the sensor body (11) comprises two opposing parallel flat surfaces (28a, 28b).Sensor bearing assembly according to any one of claims 1 to 4, wherein the impulse ring (14) comprises a radial portion (14a) and an axial portion (14b), the radial portion (14a) being fixed to the outer ring (20) of the bearing (12) and protruding radially inward with respect to the outer ring (20), the axial portion (14b) protruding axially into a chamber (36) provided on the base (32) of the sensor body (11).The sensor bearing assembly according to claim 5, wherein the axial portion (14b) is provided with a plurality of detection targets (14c).The sensor bearing assembly of claim 6, wherein the detection targets (14c) of the plurality of detection targets (14c) are evenly spaced around a perimeter of the axial portion (14b).A sensor bearing assembly according to any one of claims 1 to 7, wherein the sensor device (16) is provided with a cable (16b) extending radially outwards with respect to the base (32) and at a predetermined angle.A sensor carrier (38) comprising: - a carrier (40) having two opposing arms (42a, 42b), and - a sensor bearing assembly (10) according to any one of claims 1 to 8, characterized in that the sensor bearing assembly (10) is attached to the carrier (40) with a pin (44) inserted into the inner through hole (26) of the sensor body (11) and into two opposing holes (43a, 43b) provided on each of the arms (42a, 42b), the pin (44) having a cross section (44a) corresponding respectively to the cross section (28) of the inner through hole (26) of the sensor body (11) and the cross section (43c) of each of the two opposing holes (43a, 43b) to block relative rotation between the sensor bearing assembly (10) and the carrier (40).Pulley unit (36) comprising: - a sensor support (38) according to claim 9, - a pulley (46) fixed on the outer ring (20) of the bearing (12) of the sensor bearing assembly (10), and - a flexible drive (48) fixed on the pulley (46).

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