Sensor bearing unit and assembly

Abstract

The sensor bearing unit includes: a bearing including an inner ring and an outer ring centered on an axis; and a pulse ring fixed to the outer ring, the pulse ring including a radial portion (64) protruding outward in a radial direction relative to the outer ring. A radial portion (64) of the pulse ring is provided with two spaced-apart tabs (74a, 74b) extending in the axial direction and facing each other in the circumferential direction.

Description

Technical Field

[0001] The present invention relates to a sensor bearing unit and a sensor bearing assembly. The sensor bearing unit comprises a bearing and an impulse ring. The sensor bearing assembly comprises the sensor bearing unit, a sensor device and a spacer shaft supporting the sensor device.

[0002] The present invention relates to a sensor bearing unit and a sensor bearing assembly, which are particularly suitable for a hub motor or an in-wheel motor that provides a driving torque for propelling a vehicle such as a motorcycle, bicycle, tricycle or quadricycle. Background Art

[0003] Today, sensor bearing assemblies and sensor bearing units are commonly used in a wide range of technical fields, for example in the automotive industry and aerospace. These assemblies and units provide high-quality signals and transmission while allowing integration in simpler and more compact devices.

[0004] A sensor bearing assembly generally comprises a bearing, an impulse ring fixed to a rotatable ring of the bearing, and a sensor unit or device for determining the angular position of the impulse ring relative to a fixed ring of the bearing.

[0005] Typically, the sensor unit is separately mounted on a stationary part of an associated motor.

[0006] Generally, assembly of the sensor unit in a wheel hub motor is difficult and great care must be taken to ensure accurate positioning for reliable measurements. Summary of the invention

[0007] An object of the present invention is to overcome these disadvantages.

[0008] The present invention relates to a sensor bearing unit, comprising: a bearing including an inner ring and an outer ring centered on an axis; and an impulse ring fixed to the outer ring of the bearing.

[0009] According to one general feature, the impulse ring comprises a radial portion projecting radially outwards relative to the outer ring.

[0010] According to another general feature, the radial portion of the impulse ring is provided with two spaced-apart tabs extending in the axial direction and facing each other in the circumferential direction.

[0011] Such a tab forms a reference element which facilitates the positioning of the impulse ring and its assembly with the stationary part of the hub motor.

[0012] In one embodiment, the radial portion of the impulse ring is provided with a plurality of openings spaced apart in the circumferential direction, and the tabs are offset radially inwardly relative to the openings.

[0013] This design helps prevent assembly errors during the manufacturing process.

[0014] For example, the radial portion of the impulse ring is provided with a through-aperture having two opposite lateral edges, each tab extending from one of the lateral edges.

[0015] Advantageously, the tab is integral with the impulse ring. Such an impulse ring is easy to manufacture, since no assembly with the tab is required.

[0016] Preferably, the tab is formed by partially cutting a radial portion of the impulse ring.

[0017] The manufacture of such an impulse ring is further simplified.

[0018] Advantageously, the radial portion of the impulse ring is axially offset relative to the bearing, and the tab extends axially on one side of the bearing.

[0019] This design further prevents assembly errors during the manufacturing process.

[0020] In one embodiment, the impulse ring includes an axial portion mounted on the outer surface of the outer ring, and the radial portion extends from the axial portion.

[0021] Preferably, the impulse ring further includes a rib extending radially inwardly from the axial portion and bearing against a lateral face of the outer ring in the axial direction.

[0022] Such ribs improve the fixation of the impulse ring to the outer ring of the bearing.

[0023] For example, the impulse ring is made of metal.

[0024] This feature facilitates fixing the impulse ring to the outer ring of the bearing, for example by press-fitting.

[0025] According to another aspect, the present invention relates to a sensor bearing assembly, which comprises a sensor bearing unit as specified above; and a sensor device for detecting a rotation parameter of the impulse ring, the sensor device comprising a sensor housing and at least one sensor element supported by the sensor housing and cooperating with the impulse ring.

[0026] The sensor-bearing assembly further comprises a spacer shaft to which the sensor housing of the sensor device and the inner ring of the bearing are fixed.

[0027] This sensor bearing assembly design simplifies the manufacturing process by eliminating assembly errors and facilitates reliable measurement by ensuring proper positioning of assembled components. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention and its advantages will be better understood by studying the detailed description of particular embodiments given by way of non-limiting examples and illustrated by the accompanying drawings, in which:

[0029] - Figure 1 is a front view of a sensor bearing assembly according to an example of the present invention,

[0030] - Figure 2 It is along Figure 1 The section along the axis II-II,

[0031] - Figure 3 It is along Figure 1 The section along the axis III-III,

[0032] - Figure 4 yes Figures 1 to 3 A perspective view of the spacer shaft of the sensor bearing assembly,

[0033] - Figure 5 yes Figures 1 to 3 A front perspective view of the sensor housing of the sensor bearing assembly,

[0034] - Figure 6 yes Figure 5 A rear perspective view of the sensor housing,

[0035] - Figure 7 is fixed to Figure 4 Spacer shaft Figure 5 and Figure 6 A rear perspective view of the sensor housing,

[0036] - Figure 8 yes Figures 1 to 3 Rear perspective view of the impulse ring of the sensor bearing assembly,

[0037] - Fig. 9 Is installed in Figures 1 to 3 The sensor bearing assembly is on the bearing Figure 8 A front view of the impulse ring, and

[0038] - Fig.10 yes Figure 8 Front view of the impulse ring. DETAILED DESCRIPTION

[0039] Figure 1 The sensor bearing assembly 10 shown in FIG. 1 is particularly suitable for equipping a vehicle such as a motorcycle, bicycle, tricycle or quad. The sensor bearing assembly 10 has particularly interesting applications in electric motors and more generally anywhere encoding of speed, position and direction or any of these is required.

[0040] like Figures 1 to 3 As shown above, the sensor bearing assembly 10 includes a bearing 12 and an impulse ring 14 and a sensor device 16 mounted on the bearing. The bearing 12 and the impulse ring 14 form a sensor bearing unit.

[0041] The bearing 12 comprises an inner ring 18 and an outer ring 20. The inner ring 18 and the outer ring 20 are concentric and extend axially along a bearing rotation axis XX' extending in the axial direction. The outer ring 20 radially surrounds the inner ring 18. The inner ring 18 and the outer ring 20 are made of steel.

[0042] As will be described later, the sensor bearing assembly 10 further comprises a spacer shaft 22 extending in the axial direction along the bearing rotation axis XX′. The impulse ring 14 is fixed to the outer ring 20 of the bearing, and the sensor device 16 is fixed to the spacer shaft 22 .

[0043] In the example shown, the bearing 12 also comprises rows of rolling elements 23 , which are provided here in the form of balls, between raceways (not shown) formed on the inner ring 18 and the outer ring 20 .

[0044] The bearing 10 further includes a cage (not shown) for maintaining regular circumferential spacing of the rolling elements 23. The bearing 10 further includes seals 26, 28 radially arranged between the inner ring 18 and the outer ring 20 to define a closed space in which the rolling elements 23 are arranged.

[0045] The outer ring 20 is provided with a cylindrical inner surface or hole 20a and an outer cylindrical surface 20b radially opposite the hole 20a. In the example shown, an annular circular raceway for rolling elements 23 is formed by the hole 20a, the raceway pointing radially inwards. Two grooves (not shown) are also formed on the hole 20a, in which seals 26, 28 are fixed.

[0046] In this example, the outer ring 20 is also provided with two opposite radial lateral faces 20c, 20d delimiting axially the bore 20a and the outer surface 20b of said ring.

[0047] Like the outer ring 20, the inner ring 18 is provided with a cylindrical inner surface or bore 18a and an outer cylindrical surface 18b radially opposite the bore 18a. In the example shown, an annular circular raceway for the rolling elements 23 is formed by the outer surface 18b, said raceway pointing radially outwards.

[0048] The inner ring 18 is also provided with two opposite radial lateral faces 18c, 18d delimiting axially the hole 18a and the outer surface 18b of said ring. Two grooves (not indicated) are also formed on the outer surface 18b, in which the seals 26, 28 are fixed.

[0049] A recess 30 is formed on the lateral surface 18c of the inner ring. The recess 30 extends inwardly from the lateral surface 18c in the axial direction. The recess 30 is oriented toward the sensor housing 42 in the axial direction. Fig. 9 As shown above, the recess 30 is provided with two side walls 30a, 30b that delimit the recess 30 in the circumferential direction. The side walls 30a, 30b extend in the axial direction. The side walls 30a, 30b are spaced apart from each other in the circumferential direction. In the example shown, the side walls 30a, 30b are opposite to each other in the circumferential direction. As another option, in the case of a recess with a larger circumferential length, the side walls 30a, 30b may not face each other in the circumferential direction.

[0050] The recess 30 further comprises a bottom 30c connected to the side walls 30a, 30b. The bottom 30c extends in the circumferential direction. The bottom 30c is offset inwardly in the axial direction relative to the lateral surface 18c of the inner ring.

[0051] In the example shown, the recess 30 opens radially on the bore 18a of the inner ring. Alternatively, the recess 30 may remain spaced apart from the bore 18a.

[0052] In the example shown, the inner ring 18 of the bearing and the sensor device 16 are fixed on the spacer shaft 22 .

[0053] Especially if Figure 2 and Figure 4 As shown above, the spacer shaft 22 has an annular form. The spacer shaft has a first portion 32 to which the inner ring 18 of the bearing is preferably fixed by press-fitting. The bore 18a of the inner ring is fixed to the outer diameter of the first portion 32.

[0054] In the example shown, the spacer shaft 22 is also provided with a second portion 34 having an outer diameter greater than that of the first portion 32. The sensor device 16 is fixed to the second portion 34. In an alternative embodiment, the spacer shaft 22 may include only the first portion 32 or the second portion 34 having a greater length.

[0055] The spacer shaft 22 is provided with an axial groove 36 formed on the outer surface of the spacer shaft. More precisely, the axial groove 36 is formed on the outer surface 38 of the second portion 34. The groove 36 extends on the outer surface 38 in the axial direction.

[0056] The groove 36 is oriented radially toward the sensor housing 42. The groove 36 is provided with two facing axial side walls 36a, 36b that delimit the axial groove 36 in the circumferential direction. The side walls 36a, 36b are spaced apart from each other in the circumferential direction. The groove 36 also includes a bottom 36c connected to the side walls 36a, 36b. The bottom 36c is offset radially inwardly relative to the outer surface 38.

[0057] Here, the bottom 36c is connected to each side wall 36a, 36b by a small radius fillet edge. Alternatively, the bottom 36c can be connected to the side walls 36a, 36b without any fillet edge. Here, the bottom 36c has a double slope profile that points radially inward. Alternatively, the bottom 36c can be flat.

[0058] In the example shown, the spacer shaft 22 is further provided with a circumferential groove 40 formed on its outer surface. The circumferential groove 40 is here formed on the outer surface 38 of the second portion 34. The circumferential groove 40 extends from the side wall 36a of the axial groove and joins the side wall 36b.

[0059] The groove 40 is oriented radially toward the sensor housing 42. The groove 40 is provided with two opposite radial side walls 40a, 40b that delimit the groove 40 in the axial direction. The side walls 40a, 40b are spaced apart from each other in the axial direction. The groove 40 also includes a bottom 40c connected to the side walls 40a, 40b. The bottom 40c is offset radially inwardly relative to the outer surface 38 and is offset radially outwardly relative to the bottom 36c. As another option, the bottom 40c can be flush with the bottom 36c in the radial direction.

[0060] Here, the bottom 40c is connected to each side wall 40a, 40b by a small radius rounded edge. As another option, the bottom 40c can be directly connected to the side walls 40a, 40b without any rounded edges.

[0061] The sensor device 16 includes a sensor body or housing 42 and a sensor element 41 supported by the sensor housing 42. The sensor device 16 also includes a printed circuit board 43 fixed to the sensor housing 42 and supporting the sensor element 41. As will be described later, the sensor device 16 also includes a cable 60 supported by the sensor housing 42 and including wires (not shown) connected to the printed circuit board 43.

[0062] The sensor housing 42 has an annular form. Figure 2 , Figure 5 and Figure 6 As shown above, the sensor housing 42 includes an annular inner axial mounting portion 44 fixed to the spacer shaft 22, an annular outer axial portion 46 radially surrounding the inner mounting portion 44, and a plurality of primary arms 48 spaced apart in the circumferential direction and extending radially between the inner axial portion 44 and the outer axial portion 46. Preferably, the sensor housing 42 is provided with at least three primary arms 48.

[0063] As mentioned above, the inner mounting portion 44 is fixedly secured to the spacer shaft 22. Preferably, the sensor housing 42 is overmoulded on the spacer shaft 22. The sensor housing 42 is made as a single piece. The sensor housing 42 is made of a synthetic material. For example, the sensor body 42 may be made of PA6.6 or PBT.

[0064] The inner mounting portion 44 is provided with at least a first protrusion 56 ( Figure 2 The first protrusion 56 abuts against the side walls 30a, 30b of the recess 30 in the circumferential direction.

[0065] The inner mounting portion 44 is provided with a second protrusion 58 extending inside the axial groove 36 of the spacer shaft 22. The first protrusion 56 extends from one end of the second protrusion 58 in the axial direction.

[0066] Preferably, the second protrusion 58 protrudes outward in the axial direction relative to the spacer shaft 22 on the side opposite to the first protrusion 56 in the axial direction. The second protrusion 58 protrudes outward in the axial direction relative to the main arm 48 and the mask portion 50.

[0067] The second protrusion 58 abuts against the side walls 36 a , 36 b of the axial groove 36 of the spacer shaft 22 in the circumferential direction.

[0068] The inner mounting portion 44 of the sensor housing is also provided with a third protrusion 59 extending inside the circumferential groove 40 formed on the outer surface of the spacer shaft 22. Alternatively, the inner mounting portion 44 may not be provided with the third protrusion.

[0069] The third protrusion 59 abuts against the side walls 40 a , 40 b of the circumferential groove 40 of the spacer shaft 22 in the axial direction.

[0070] Protrusions 56 , 58 , and 59 are formed during molding of sensor housing 42 .

[0071] In the example shown, the sensor housing 42 also comprises a shielding portion 50 , which is a radial portion extending circumferentially between two consecutive main arms 48 and connected to the outer axial portion 46 .

[0072] Here, the sensor housing 42 also includes at least one secondary arm 52 extending radially between the inner mounting portion 44 and the inner edge 54 of the shielding portion 50. The sensor housing 42 is also provided with a rib 53, which extends from the shielding portion 50 in the axial direction and extends between two consecutive main arms 48 in the circumferential direction. The secondary arms 52 are regularly spaced between two consecutive main arms 48. As another option, the secondary arms 52 may be irregularly spaced between two consecutive main arms 48. In another embodiment not shown in the figure, a plurality of secondary arms 52 may be regularly or irregularly spaced between two consecutive main arms 48.

[0073] A primary opening 49 is delimited in the circumferential direction by two consecutive primary arms 48 and in the radial direction by the inner axial mounting portion 44 and the outer axial portion 46. In the example shown, the housing 42 is provided with six primary openings 49.

[0074] A secondary opening 51 is defined between two consecutive main arms 48 in the circumferential direction and is defined in the radial direction by the inner axial mounting portion 44 and the inner edge 54 of the shielding portion 50. Here, the secondary opening 51 is divided into two by the secondary arm 52.

[0075] The shield part 50 of the sensor housing supports the printed circuit board 43, which is fixed to the shield part 50 by any suitable means, here by screwing. The printed circuit board 43 is radially centered between the outer axial part 46 of the sensor housing and the rib 53.

[0076] The printed circuit board 43 has two opposite inner and outer faces defining its thickness. The inner face of the printed circuit board 43 faces the shielding portion 50 and is completely covered by the shielding portion 50. The inner face of the printed circuit board 43 is kept away from the shielding portion 50 in the axial direction. The outer face of the printed circuit board 43 is oriented toward the impulse ring 14 in the axial direction.

[0077] The shielding part 50 of the sensor housing and the printed circuit board 43 together define a chamber 62 in the axial direction for accommodating the wires of the cable 60. The chamber 62 is axially bounded by the shielding part 50 and the inner face of the printed circuit board 43. The chamber 62 is radially bounded by the outer axial part 46 of the sensor housing and the ribs 53. The sensor 41 is mounted on the inner face of the printed circuit board 43. Therefore, the sensor 41 is located inside the chamber 62.

[0078] As mentioned above, a cable 60 is supported by the sensor housing 42. The cable 60 is arranged on the side opposite to the printed circuit board 43 in the axial direction relative to the shielding portion 50. The shielding portion 50 has an opening 55 extending through the thickness thereof, and the wires of the cable 60 extend through the opening 55 to be connected to the printed circuit board 43.

[0079] In the example shown, in order to install the cable 60, the sensor housing 42 is also provided with a channel 61, in which the cable 60 is clamped and routed. The opening 55 opens into the channel 61. The channel 61 extends radially along the shielding portion 50. Here, the channel 61 protrudes radially outward relative to the outer axial portion 46. The channel 61 opens outward in the axial direction for clamping the cable and properly routing the cable. Here, the channel 61 is open along its entire length in the axial direction to facilitate the introduction of the cable 60 by axial pushing. For example, the channel 61 has a C-shaped or U-shaped cross-section. The cable 60 protrudes radially outward relative to the channel 61.

[0080] In the disclosed example, the sensor device 16 is provided with a connection cable 60 for transmitting the sensed data. As another option, in the case of a wireless sensor element, the sensor device 16 may be free of such a connection cable. In this case, the sensor housing 42 does not comprise the channel 61 .

[0081] As previously mentioned, in the disclosed example, the sensor housing 42 includes a main arm 48 extending radially between the inner axial portion 44 and the outer axial portion 46. Alternatively, instead of the arm 48 or instead of the arm 48 and the shielding portion 50, the sensor housing 42 may include an annular radial portion 48 extending radially between the inner axial portion 44 and the outer axial portion 46.

[0082] As mentioned previously, the impulse ring 14 is fixed to the outer race 18 of the bearing. The impulse ring 14 is fixed to the outer surface 20b of the outer race.

[0083] like Figure 2 , Figure 8 and Fig. 9 As shown above, the impulse ring 14 includes an annular axial portion 66, which is mounted on the outer surface 20b of the outer ring 20, and a radial portion 64 extends from the annular axial portion 66. The radial portion 64 protrudes radially outward relative to the axial portion 66 and the outer ring 20. The axial portion 66 of the impulse ring 14 is preferably fixed to the outer surface 20b of the outer ring 20 by press fitting ( / press fitting).

[0084] The radial portion 64 of the impulse ring axially faces the printed circuit board 43 and the arms 48, 52 of the sensor housing. The radial portion 64 extends radially towards the outer axial portion 46 of the sensor housing while remaining away from said outer axial portion.

[0085] Here, the impulse ring 14 also comprises an annular rib 68 which extends radially inwardly from the axial portion 66 and which is axially bearing against the lateral face 20 d of the outer ring 20 .

[0086] In the example shown, the impulse ring 14 is provided with a plurality of through openings 70 formed on the radial portion 64. The openings 70 extend through the axial thickness of the radial portion 64. The openings 70 are spaced apart in the circumferential direction, here the openings 70 are regularly spaced apart in the circumferential direction. The openings 70 are identical to each other here. A tooth 72 is provided between each pair of consecutive openings 70. Thus, the impulse ring 14 is provided with alternating teeth 72 and openings 70. In the example shown, twenty-four openings 70 and twenty-four teeth 72 are provided. As another alternative, a different number of openings 70 and teeth 72 can be foreseen.

[0087] As mentioned above, each sensor element 41 is mounted on the printed circuit board 43 on one side in the axial direction of the shielding portion 50 of the housing inside the cavity 62 .

[0088] Each sensor element 41 cooperates with the impulse ring 14 via a printed circuit board 43. Each sensor element 41 is aligned radially with one of the teeth 72 or openings 70 of the impulse ring 14. The sensor elements 41 are regularly ( / equally) spaced apart in the circumferential direction. For example, the sensor device 16 may include three sensor elements 41. As another option, a different number of sensor elements 41 may be foreseen, such as one or two sensor elements or at least four sensor elements.

[0089] Preferably, the sensor elements 41 use inductive technology. Each sensor element 41 may include an inductive switch sensor, such as a sensing coil. The switch of each sensor element is triggered by a pulse ring 14 made of metal. The teeth 72 and openings 70 of the pulse ring are used as differential inductance field references.

[0090] As another option, the pulse ring 14 and the sensor element 41 may use any other suitable technology instead of inductive technology. For example, optical technology or magnetic technology may be implemented. In the case of magnetic technology, the pulse ring 14 may include alternating north and south poles, and the sensor element may include a Hall effect sensor.

[0091] like Figures 8 to 10 As shown in FIG. 1 , the radial portion 64 of the impulse ring is provided with two spaced tabs 74a, 74b extending in the axial direction and facing each other in the circumferential direction. The tabs 74a, 74b are spaced apart in the circumferential direction. The tabs 74a, 74b extend axially on one side of the axial portion 66 and the bearing 12. The tabs 74a, 74b extend axially on the side opposite to the sensor housing 42. The tabs 74a, 74b are offset radially inward relative to the opening 70.

[0092] Here, the radial portion 64 of the impulse ring is provided with a through-aperture 76 having two opposite lateral edges 76a, 76b, each tab 74a, 74b extending from one of the lateral edges 76a, 76b.

[0093] In this example, the tabs are formed by partially cutting the radial portion 64 of the impulse ring 14. Alternatively, the tabs may be formed by any other suitable method, such as stamping. In this case, the tabs 74a, 74b are integral with the impulse ring 14. Alternatively, the tabs 74a, 74b may be separate parts fixed to the radial portion 64 of the impulse ring by any suitable means.

[0094] In the example shown, the sensor bearing assembly is provided with a rolling bearing comprising one row of rolling elements. As another option, the rolling bearing may comprise at least two rows of rolling elements. In the example shown, the rolling elements are balls. As another option, the rolling bearing may comprise other types of rolling elements, such as rollers. In another variant, the rolling bearing may also be provided with a sliding bearing without rolling elements.

Claims

1. A sensor bearing unit, comprising: - a bearing (12) comprising an inner ring (18) and an outer ring (20) centered on the axis (XX'), and an impulse ring (14) fixed to the outer ring (20) of the bearing, the impulse ring comprising a radial portion (64) protruding radially outwards relative to the outer ring (20), Characterized in that the radial portion (64) of the impulse ring is provided with two spaced-apart tabs (74a, 74b) extending in the axial direction and facing each other in the circumferential direction.

2. The sensor bearing unit according to claim 1, characterized in that: The radial portion (64) of the impulse ring is provided with a plurality of openings (70) spaced apart in the circumferential direction, the tabs (74a, 74b) being radially inwardly offset relative to the openings.

3. The sensor bearing unit according to claim 1 or 2, characterized in that: The radial portion (64) of the impulse ring is provided with a through aperture (76) having two opposite lateral edges (76a, 76b), each tab (74a, 74b) extending from one of the lateral edges.

4. The sensor-bearing unit according to any one of the preceding claims, characterized in that The tabs (74a, 74b) are integral with the impulse ring (14).

5. The sensor bearing unit according to claim 4, characterized in that: The tabs (74a, 74b) are formed by partially cutting a radial portion (64) of the impulse ring (14).

6. The sensor-bearing unit according to any of the preceding claims, characterized in that The radial portion (64) of the impulse ring (14) is axially offset relative to the bearing (12), and the tabs (74a, 74b) extend axially on one side of the bearing (12).

7. The sensor-bearing unit according to any of the preceding claims, characterized in that The impulse ring (14) includes an axial portion (66) mounted on the outer surface (20b) of the outer ring (20), and the radial portion (64) extends from the axial portion (66).

8. The sensor bearing unit according to claim 7, characterized in that: The impulse ring (14) further comprises a rib (68) which extends radially inward from the axial portion (66) and bears axially against a lateral surface (20d) of the outer ring (20).

9. The sensor-bearing unit according to any of the preceding claims, characterized in that The impulse ring (14) is made of metal.

10. A sensor bearing assembly, comprising: - a sensor-bearing unit according to any of the preceding claims, and - a sensor device (16) for detecting a rotation parameter of the impulse ring, the sensor device (16) comprising a sensor housing (42) and at least one sensor element (41) supported by the sensor housing (42) and cooperating with the impulse ring (14), and A spacer shaft (22) to which the sensor housing (42) of the sensor device (16) and the inner ring (18) of the bearing (12) are fixed.

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