Bearing arrangement with absolute rotary sensor

Abstract

A bearing device (1) with an absolute rotary sensor includes a bearing (3) and a detected member (5) having a detected portion (19) fixed to a rotation-side raceway ring of the bearing (3) and having two rows of magnetic tracks provided across a circumference of a ring-shaped core (17). The bearing device (1) with the absolute rotary sensor is provided with a rotary sensor unit (7) having a rotary sensor (21) fixed to a fixed-side raceway ring of the bearing (3) and detecting rotation of the detected portion (19) in a non-contact manner, a sensor substrate (23) on which the rotary sensor (21) is mounted, and a sensor housing (25) covering the sensor substrate (23) and in which the sensor substrate (23) is installed.

Description

[0001] Related applications

[0002] This application claims priority to JP Patent Application 2021-051481, filed on March 25, 2021, which is incorporated herein by reference in its entirety as part of this application. Technical Field

[0003] This invention relates to a bearing device with an absolute rotation sensor. Background Technology

[0004] As bearings that rotatably support joints and other components of industrial robots, bearing devices including absolute rotation sensors capable of high-precision control are used. For example, a bearing device with an absolute rotation sensor has been proposed (see, for example, Patent Document 1).

[0005] The bearing assembly requires a total of three sensors, cables connected to these sensors, and other components. It also requires positioning the two absolute angle detection units with a 90° phase difference between them, making the assembly process complex.

[0006] Therefore, as an absolute rotation sensor combined with a bearing, a double-track rotation sensor can be considered. This double-track rotation sensor includes two rows of magnetic tracks on the circumference of the toroidal core iron: a magnetic track for angle detection (main track) and a magnetic track for phase difference detection (secondary track). Thus, it is possible to detect rotation angle, rotation speed, rotation direction, etc. with high precision using only one sensor.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: JP Patent No. 4587656 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] Therefore, by combining a double-track rotary sensor with a bearing, it is expected that a bearing device with an absolute rotary sensor can be realized that has fewer parts and is easier to assemble. However, no specific structure for combining a double-track rotary sensor with a bearing has been proposed.

[0012] Therefore, the object of the present invention is to provide a bearing device with an absolute rotation sensor, which simplifies the structure with fewer parts and is easy to assemble by combining a double-row track-type rotation sensor with the bearing.

[0013] Technical solutions for solving the problem

[0014] To achieve the above objectives, the bearing device with an absolute rotation sensor of the present invention includes:

[0015] The bearing has a rotating side raceway, a fixed side raceway opposite to the rotating side raceway, and rolling elements between the rotating side raceway and the fixed side raceway.

[0016] The component to be tested is ring-shaped and fixed on the rotating side raceway of the bearing. It has an annular core and a tested part having two rows of magnetic tracks arranged circumferentially across the core.

[0017] A rotation sensor unit, which is fixed to the fixed side raceway of the bearing, includes: a rotation sensor that detects the rotation of the detected part in a non-contact manner; a sensor substrate on which the rotation sensor is mounted; and a sensor housing that covers the sensor substrate and on which the sensor substrate is mounted.

[0018] According to this structure, since the detected part of the rotary sensor is set as a double-row track type, and the rotary sensor is mounted on the sensor housing while mounted on the sensor substrate, the structure of the bearing device can be simplified with fewer parts, and the assembly operation becomes easier.

[0019] In one embodiment of the invention, a mounting groove may be formed on the sensor housing for inserting the sensor substrate, thereby positioning the sensor substrate in both the axial and radial directions. With this structure, the positioning of the rotating sensor and the detected part can be achieved simply by inserting the sensor substrate into the mounting groove, ensuring the sensor gap. Therefore, a bearing device capable of high-precision rotational detection can be assembled with a simple operation.

[0020] In one embodiment of the present invention, the sensor substrate may be positioned with the end of the detected component as a reference. With this structure, the positioning of the rotating sensor can be easily performed by using the end of the detected component as a reference.

[0021] In one embodiment of the invention, the protrusion provided on the sensor housing may have a guide surface that guides the component externally fitted into the protrusion in a direction orthogonal to the axial direction. With this structure, during the assembly process of the bearing assembly, a pushing operation in a direction orthogonal to the axial direction can be easily and reliably performed using the guide surface of the protrusion on the sensor housing. This allows for positioning that minimizes the sensor position offset caused by the gap between the rolling elements and raceways within the bearing. Therefore, a bearing assembly capable of high-precision rotation detection can be assembled with simple operations.

[0022] In one embodiment of the invention, the sensor housing may be configured such that the sensor substrate can be inserted into the mounting groove from the side opposite to the bearing. With this configuration, the sensor substrate can be easily mounted from the opposite side of the bearing during the bearing assembly process, thus enabling the assembly of a bearing device capable of high-precision rotation detection with simpler operations.

[0023] In one embodiment of the present invention, the receiving portion of the sensor housing that accommodates the sensor substrate may include a resin material filling the space between the inner wall surface of the receiving portion and the sensor substrate, and a cover member covering the end of the receiving portion opposite to the bearing. With this structure, a rotary sensor and a sensor substrate can be reliably fixed and mounted on the sensor housing.

[0024] One embodiment of the bearing device of the present invention can also be mounted on an electric vertical takeoff and landing (EVTOL) aircraft, which includes a plurality of drive units having rotor blades and motors for rotating the rotor blades, and flying by rotating the rotor blades. The bearing device includes a bearing that rotatably supports the rotating shaft of the drive unit. With this structure, even when the bearing device is applied to an EVTOL aircraft (so-called flying car) intended as a means of transportation to replace automobiles, the aforementioned advantages can be obtained.

[0025] Any combination of at least two structures disclosed in the claims and / or description and / or drawings is also included in this invention. In particular, any combination of two or more of the claims in the claims is also included in this invention. Attached Figure Description

[0026] The invention will become clearer from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to limit the scope of the invention. The scope of the invention is defined by the claims. In the drawings, the same reference numerals in the plurality of figures denote the same or equivalent parts.

[0027] Figure 1 This is a longitudinal sectional view illustrating the general structure of a bearing device with an absolute rotation sensor according to one embodiment of the present invention.

[0028] Figure 2 To indicate in Figure 1 A longitudinal sectional view of the component under test used in the bearing assembly;

[0029] Figure 3 To indicate in Figure 1 A top view of the component being inspected used in the bearing assembly;

[0030] Figure 4 To indicate in Figure 1 A front view of the sensor unit used in the bearing assembly;

[0031] Figure 5A To illustrate Figure 1 A cross-sectional view of the radial internal clearance of the bearing used in the bearing assembly;

[0032] Figure 5B To illustrate Figure 1 A cross-sectional view of the axial internal clearance of the bearing used in the bearing assembly.

[0033] Figure 5C To illustrate Figure 1 A cross-sectional view of the axial internal clearance of the bearing used in the bearing assembly.

[0034] Figure 6 To indicate Figure 1 A schematic diagram illustrating an example of the assembly method for a bearing assembly;

[0035] Figure 7 To indicate in Figure 6 The front view of the push-fit component and base used in the assembly method;

[0036] Figure 8 To indicate in Figure 1 A schematic diagram of an example of the alignment method for the sensor unit used in the bearing assembly;

[0037] Figure 9 A longitudinal sectional view illustrating the general structure of a bearing device with an absolute rotation sensor according to another embodiment of the present invention;

[0038] Figure 10 To indicate Figure 9 A schematic diagram illustrating an example of the assembly method for a bearing assembly;

[0039] Figure 11 A perspective view of an electric vertical take-off and landing machine with a bearing device having an absolute rotation sensor, according to one embodiment of the present invention.

[0040] Figure 12 To indicate Figure 11 A longitudinal sectional view of a portion of the motor in the drive unit of an electric vertical take-off and landing machine. Detailed Implementation

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

[0042] exist Figure 1 The diagram shows a bearing device 1 (hereinafter referred to as "bearing device") with an absolute rotation sensor according to one embodiment of the present invention. The bearing device 1 includes a bearing 3, an annular detection component 5 which is the object of rotation detection, and a rotation sensor unit 7.

[0043] The bearing in this embodiment is configured as a ball bearing 3, which includes an inner ring 11, an outer ring 13 arranged opposite to the inner ring 11, and balls serving as rolling elements 15 sandwiched between the inner ring 11 and the outer ring 13. In this example, the bearing 3 is configured as an inner ring rotation type. That is, the inner ring 11 is configured as a rotating side raceway ring, and the outer ring 13 is configured as a fixed side raceway ring.

[0044] The component 5 being tested is mounted on the inner ring 11, which serves as the rotating side raceway. For example... Figure 2 As shown, the component to be tested 5 includes an annular core 17 and a test portion 19 having two rows of magnetic tracks arranged across the circumference of the core 17. More specifically, the core 17 has a cylindrical portion 17a and a mounting portion 17b with a diameter smaller than that of the cylindrical portion 17a, and the test portion 19 is formed on the outer circumferential surface of the cylindrical portion 17a.

[0045] Specifically, the component to be tested 5 in this embodiment is formed by magnetizing the surface of the unmagnetized magnetic component with multiple rows (two rows in this example) of magnetic tracks with different numbers of magnetizing pole pairs after forming an annular unmagnetized magnetic component including a core iron 17. The multiple rows of magnetic tracks constitute the tested section 19. The unmagnetized magnetic component is formed, for example, by placing a rubber material in which magnetic powder is mixed with the outer peripheral surface of the core iron 17, which is made of a metal ring, into a mold and vulcanizing and bonding it together with the core iron 17, or by integrally molding a material mixed with plastic material and magnetic powder with the core iron 17. The core iron 17 is formed, for example, by stamping an iron-based rolled steel sheet.

[0046] A detection portion 19 is formed on the outer peripheral surface of the cylindrical portion 17a of the core iron 17. For example... Figure 3As shown, by making the magnetization patterns different for the two rows of magnetic tracks of the detection part 19, and by utilizing, for example, the difference between pole pairs generated after one revolution, the absolute angle of the rotation axis can be detected. By using such a multi-row magnetized track as the detection part 5, high-precision rotation detection can be performed using only a single rotation sensor.

[0047] like Figure 1 As shown, the rotation sensor unit 7 is mounted on the fixed side raceway ring of the bearing 3, i.e., the outer ring 13. The rotation sensor unit 7 includes: a rotation sensor 21 that detects the rotation of the detected part 19 in a non-contact manner; a sensor substrate 23 on which the rotation sensor 21 is mounted; and a sensor housing 25 that covers the sensor substrate 23 and mounts the sensor substrate 23.

[0048] A rotation sensor 21 is mounted on the radially inward side of a sensor substrate 23 facing the bearing 3, opposite to the detected component 5. In the following description, the surface of the sensor substrate 23 on which the rotation sensor 21 is mounted is referred to as surface 23a, and the opposite surface is referred to as back surface 23b. In this example, a magnetic sensor that generates an output signal corresponding to the magnetic flux density is used as the rotation sensor 21. A connector 27 is mounted on the back surface 23b of the sensor substrate 23, through which a cable 29 is connected to the rotation sensor 21. This cable 29 is used for outputting a signal from the rotation sensor 21 to the outside and for supplying power to the rotation sensor 21.

[0049] like Figure 4 As shown, the sensor housing 25 has a bearing 3 ( Figure 1 The sensor substrate 23 has a concentrically arranged arc-shaped portion 31 and a receiving portion 33 that protrudes radially outward from the arc-shaped portion 31. The receiving portion 33 is formed in such a way that it constitutes a protrusion protruding from the arc-shaped portion 31. A mounting groove 35 is formed on the inner wall surface of the receiving portion 33 for inserting the sensor substrate 23 and positioning the sensor substrate 23 in the axial direction and radial direction.

[0050] The outer sidewall of the receiving portion 33 is formed to constitute a guide surface 37, which guides the component externally fitted onto the receiving portion 33 in a direction orthogonal to the axial direction. More specifically, as... Figure 4 As shown, the portion of the receiving portion 33 of the sensor housing 25 that protrudes from the arc-shaped portion 31 is formed in a generally square shape, having a top wall 33a covering the radially outer side and a front wall 33b extending from one side (bearing 3 side) of the top wall 33a in the axial direction in a direction orthogonal to the top wall 33a. Figure 1The receiving portion 33 has two side walls 33c extending from each end of the top wall 33a in a direction orthogonal to the top wall 33a. That is, the two side walls of the receiving portion 33 have outward side wall surfaces extending perpendicularly and parallel to each other from each end of the front wall to the side opposite to the bearing 3. These two side wall surfaces function as guide surfaces 37 for guiding components externally fitted onto the receiving portion 33 in a direction orthogonal to the axial direction.

[0051] Furthermore, mounting grooves 35 extending parallel to the axial direction are formed on the inner wall surfaces of the two side walls 33c of the receiving portion 33. For example... Figure 1 As shown, the opening on the side opposite to the bearing 3 of the sensor housing 25 also includes a receiving portion 33, which is formed separately from the sensor housing 25 and is covered by a cover member 39 that is detachably mounted on the sensor housing 25.

[0052] In this embodiment, the sensor housing 25 is mounted on the fixed-side component of the bearing 3, i.e., the outer ring 13, via the outer ring component 41. Specifically, the outer ring component 41 has a cylindrical large-diameter portion that fits into the outer peripheral surface of the arcuate portion 31 of the sensor housing 25 and a cylindrical small-diameter portion that fits into the inner peripheral surface of the outer ring 13. On the other hand, the detected component 5 is mounted on the inner ring 11, which is the rotating-side component of the bearing 3, via the annular adapter component 43. The coupling component 43 has a cylindrical small-diameter portion that fits into the inner peripheral surface of the mounting portion 17b of the core iron 17 of the detected component 5 and a cylindrical large-diameter portion that fits into the outer peripheral surface of the inner ring 11. Furthermore, the sensor housing 25 may also be directly mounted on the fixed-side component of the bearing 3 (in this example, the outer ring 13), and the detected component 5 may also be directly mounted on the rotating-side component of the bearing 3 (in this example, the inner ring 11).

[0053] By forming the receiving portion 33 of the sensor housing 25 as described above, the accurate positioning of the rotating sensor 21 and the detected portion 19 becomes easier during the assembly process of the bearing device 1 described later.

[0054] like Figures 5A to 5C As shown, in the ball bearing 3, the rolling elements 15 are generally assembled such that there are radial internal clearances δ and axial internal clearances δ1 and δ2 between the inner ring 11 and the outer ring 13. Furthermore, the radial internal clearances δ, axial internal clearances δ1 and δ2 refer to the amount of movement required to fix either the inner ring 11 or the outer ring 13 and allow the other to move in the radial or axial direction. Generally, the axial internal clearances δ1 and δ2 are 8 to 10 times the size of the radial internal clearance δ. By forming the axial internal clearances δ1 and δ2, for example, when the outer ring 13 of the ball bearing 3 is fixed, the inner ring 11 can move only the same amount in the axial direction around the bottom of the raceway grooves of the inner ring 11 and the outer ring 13.

[0055] Therefore, with the bearing 3 set in a state where the centers of the raceway grooves of the inner ring 11 and the outer ring 13 are aligned, when... Figure 1 When the rotation sensor 21 is mounted on the sensor housing 25 fixed to the outer ring 13 side of the bearing 3, the axial movement of the detected component 5 is controlled within 4 to 5 times the radial internal clearance δ, centered on the bottom of the raceway groove. However, when the centers of the grooves of the inner ring 11 and outer ring 13 of the bearing 3 are not aligned, the rotation sensor 21 is sometimes assembled with the inner ring 11 biased in one axial direction. In this case, if the bearing 3 moves in the opposite direction, it is possible to move a maximum distance of 8 to 10 times the radial internal clearance δ in the axial direction. As a result, the center of the rotation sensor 21 is significantly offset from the center of the two rows of tracks of the detected part 19, which may result in the rotation sensor 21 failing to detect the rotation of the detected part 19.

[0056] To avoid such adverse conditions, the bearing device 1 of this embodiment, during the assembly process, such as... Figure 6 As shown, the axial orientation is determined using the method described below. Furthermore, in Figure 6 In the diagram, a top view is shown at the top of each step, and a longitudinal sectional view is shown at the bottom.

[0057] With the sensor housing 25 and the detected component 5 assembled on the bearing 3, the inner ring 11 of the bearing 3 is engaged with a temporary positioning shaft 47 mounted vertically on the base 45. At this time, the temporary shaft 47 is inserted with the bearing 3 below and the sensor housing 25 and the detected component 5 above. A guide groove 49 is formed on the upper surface of the base 45, which, when viewed from above, passes through the center of the receiving portion 33 of the sensor housing 25 and extends radially along the bearing 3. A generally square-shaped pushing member 51 is provided at the position of the guide groove 49 on the base 45. Figure 7 As shown, a guide protrusion 53 with a shape that engages with the guide groove 49 is provided on the bottom surface of the pressing member 51, and the pressing member 51 is set in such a way that the guide protrusion 53 engages with the guide groove 49 (step A).

[0058] In this state, such as Figure 6As shown, the upper portion of the pressing member 51 faces the receiving portion 33 of the sensor housing 25. A guide recess 55 is formed on the upper portion of the pressing member 51; this guide recess 55 is a recess with a shape corresponding to the outer shape of the receiving portion 33 of the sensor housing 25. The pressing member 51 with this structure is pressed into the guide groove 49 towards the center of the bearing 3 such that the guide recess 55 is pressed along the guide surface 37 of the receiving portion 33 (step B). Thus, the planar pressing portion 57 formed below the guide recess 55 of the pressing member 51 presses against the outer peripheral surface of the outer ring 13 of the bearing 3, and the rolling element 15 abuts against the bottoms 11a and 13a of the raceway grooves of the inner ring 11 and outer ring 13 of the bearing 3. Therefore, the inner ring 11 and outer ring 13 of the bearing 3 are aligned with the bottoms 11a and 13a of the raceway grooves as a reference (step C).

[0059] In this way, by providing a guide surface 37 in the receiving portion 33 of the sensor housing 25 to guide the pushing member 51, the operation of pushing the pushing member 51 in a direction orthogonal to the axial direction can be easily and reliably performed using the guide surface 37. This allows for positioning, minimizing sensor position deviation caused by the gap between the rolling element 15 and the raceways 11, 13 within the bearing 3. Therefore, a bearing device 1 capable of high-precision rotation detection can be assembled through simple operations.

[0060] Next, the method for positioning the rotation sensor 21 of the rotation sensor unit 7 relative to the bearing 3 and the detected component 5, which are positioned as described above, in the axial direction will be explained. In this example, the sensor substrate 23 is positioned with the end of the detected component 5 as a reference. Specifically, as follows... Figure 2 As shown, the width dimension of each of the two rows of tracks of the inspected part 19 of the inspected component 5 is set to be the same L. Furthermore, as... Figure 8 As shown, the sensor substrate 23 is prepared by setting the width dimension (axial dimension of bearing 3) of the sensor substrate 23 to 2L, which is the same as the overall width dimension of the detected part 19, and mounting the sensor 21 such that the distance from the center position M of the rotary sensor 21 to the end face of the sensor substrate 23 is L. The sensor substrate 23 thus fabricated is then inserted into... Figure 6 The mounting groove 35 of the sensor housing 25 of the bearing 3, as shown in the positioned state, aligns the positions of the end faces of the detected part 19 and the sensor substrate 23 on the opposite side of the bearing 3. This allows the boundary line between the two rows of tracks of the annular detected part 19 to be aligned with the central position M of the rotary sensor 21, using the bottom 11a and 13a of the raceway groove of the bearing 3 as a reference. In particular, by using the end of the detected component 5 as a reference, the rotary sensor 21 can be easily positioned.

[0061] Furthermore, in this embodiment, the internal dimension of the mounting groove 35 in the axial direction is set to a length equal to the width of the sensor substrate 23, starting from the end face of the receiving portion 33 opposite to the bearing 3. Therefore, the positioning of the detected portion 19 and the rotation sensor 21 can be easily achieved simply by inserting the sensor substrate 23 into the mounting groove 35 and pressing it into the end face of the bearing 3.

[0062] Furthermore, the receiving portion 33 of the sensor housing 25 is configured such that the sensor substrate 23 can be inserted into the mounting groove 35 from the side opposite to the bearing 3. Specifically, as Figure 1 As shown, the sensor housing 25 has an end opening on the side opposite to the bearing 3, including the receiving portion 33. The sensor housing 25 has a cover member 39 that is detachably mounted to this end and covers the opening. Therefore, during the positioning stage described above, by removing the cover member 39 of the sensor housing 25 beforehand, the sensor substrate 23 can be inserted into the mounting groove 35 from the side of the receiving portion 33 opposite to the bearing 3.

[0063] Next, the method for ensuring the radial gap (hereinafter referred to as "sensor gap") ΔT between the rotation sensor 21 and the detected part 19 will be described. Figure 4 As shown, when the distance from the center of the sensor housing 25 to the bottom surface of the mounting groove 35 is set to T1, the radius of the outer peripheral surface of the detected part 19 of the detected component 5 is set to T2, and the distance from the surface 23a of the sensor substrate 23 after sensor installation to the sensor surface (the surface opposite to the detected part 19) is set to T3, the position of the mounting groove 35, the rotation sensor 21, and the size of the sensor substrate 23 are preset in such a way as to satisfy the following formula.

[0064] ΔT=T1-T2-T3

[0065] Therefore, through and Figure 6 When the bearing 3 is positioned in the axial direction by the method described above, the sensor gap ΔT can be maintained simply by inserting the sensor substrate 23 into the mounting groove 35 of the receiving portion 33 of the sensor housing 25.

[0066] In addition, such as Figure 1As shown, the receiving portion 33 has a resin material 61 filling the space between the inner wall surface of the receiving portion 33 and the sensor substrate 23. The resin material 61 also covers the rotary sensor 21 mounted on the sensor substrate 23. As a method of filling the resin material 61, for example, a cable 29 is inserted into the connector 27, a resin material partition plate (not shown in the figure) is inserted between the rotary sensor 21 and the detected component 5, and the inside of the receiving portion 33 of the sensor housing 25 is fixed with the resin material 61. In this case, in order to prevent the resin material 61 from penetrating into the connector 27, a sealant may also be applied to the connector 27. After removing the resin material partition plate, a cover component 39 covering the sensor housing 25 is installed. In this way, by filling the space with resin material 61, the rotary sensor 21 and the sensor substrate 23 mounted on the sensor housing 25 can be reliably fixed.

[0067] Furthermore, in the above embodiments, an example of bearing 3 being configured as an inner ring rotating type was described, but as... Figure 9 As shown in other embodiments, the present invention can be applied even if the bearing 3 is of the outer ring rotating type. Furthermore, in the following description, for bearings with the same... Figures 1 to 8 The commonalities of the implementation methods described together are omitted.

[0068] In this embodiment, the bearing 3 is configured as an outer ring rotating type. That is, the inner ring 11 is configured as a fixed-side raceway ring, and the outer ring 13 is configured as a rotating-side raceway ring. In addition, in this embodiment, the detection component 5 is mounted on the outer ring 13, which is a rotating-side raceway ring, and the rotation sensor unit 7 is mounted on the inner ring 11, which is a fixed-side raceway ring.

[0069] In this embodiment, the rotation sensor 21 is also mounted on the sensor housing 25 by inserting the sensor substrate 23 on which the rotation sensor 21 is mounted into the mounting groove 35 provided in the sensor housing 25.

[0070] Additionally, a generally square guide portion 63 protrudes in the axial direction from the side opposite to the bearing 3 on the sensor housing 25. The guide portion 63 is formed as a protrusion on the sensor housing 25. The side surface of the guide portion 63 is configured to guide components externally fitted onto the sensor housing 25 in a direction orthogonal to the axial direction. Figure 10 The guide surface 37 of the push member 51 shown. By configuring the structure in such a way, as... Figure 10As shown, the bearing 3 can be easily and reliably pushed in a direction orthogonal to the axial direction using the guide surface 37. This allows for positioning, minimizing sensor position deviation caused by the gap between the rolling elements 15 and raceway rings 11 and 13 within the bearing 3. Therefore, a bearing device 1 capable of high-precision rotation detection can be assembled through simple operations.

[0071] According to the embodiments described above, the bearing device 1 with an absolute rotation sensor can simplify the structure of the bearing device 1 with fewer parts and make the assembly operation easier by setting the detection part 19 of the rotation sensor 21 to a double-row track type and mounting the rotation sensor 21 on the sensor housing 25 while it is mounted on the sensor substrate 23.

[0072] Next, an application example of the bearing device 1 according to the above-described embodiment will be described. The application of this bearing device 1 is not particularly limited; for example, it can be used in… Figure 11 The electric vertical take-off and landing machine 71 shown is shown.

[0073] In recent years, flying cars, or so-called flying cars, have attracted attention as an alternative to automobiles. Flying cars hold the promise of solving social problems and have potential applications in various situations, including intra-regional and inter-regional travel, sightseeing and leisure, emergency medical care, and disaster relief.

[0074] As flying vehicles, vertical take-off and landing (VTOL) aircraft, as shown in the image, have attracted attention. VTOL aircraft can take off and land vertically from the air and landing platform, thus eliminating the need for a runway and offering excellent convenience. In particular, in recent years, due to societal demands for CO2 reduction, electric vertical take-off and landing (eVTOL) aircraft, which utilize batteries and motors for flight, have become the mainstream of development.

[0075] Figure 11 The electric vertical takeoff and landing (EVTOL) aircraft 71 shown is a multi-rotor helicopter with a main body 73 located in the center of the fuselage and four drive units 75 arranged in the front, rear, left, and right directions. The drive units 75 are devices that generate lift and propulsion for the EVTOL aircraft 71, which flies by being driven by the drive units 75. In the EVTOL aircraft 71, there can be multiple drive units 75, and it is not limited to four.

[0076] The main body 73 has a living space for passengers (e.g., about 1 to 2 people). This living space is equipped with an operating system for determining direction of travel, altitude, etc., and instruments for displaying altitude, speed, flight position, etc. Four arms 77 extend from the main body 73, and a drive unit 75 is provided at the front end of each arm 77. In the illustrated example, to protect the rotor 79, an annular portion 81 covering the rotation periphery of the rotor 79 is integrally provided on the arm 77. Furthermore, a landing gear 83 for supporting the fuselage during landing is provided at the lower part of the main body 73.

[0077] The drive unit 75 has a rotating blade 79 and a motor 85 that rotates the rotating blade 79. In the drive unit 75, a pair of rotating blades 79 are arranged on both sides of the motor 85. Each rotating blade 79 has two blades extending radially outward.

[0078] A battery (not shown in the figure) and a control device (not shown in the figure) are provided in the main body 73. The control device is also called a flight controller. The control of the electric vertical takeoff and landing aircraft 71 is implemented by the control device as follows: The control device outputs a speed change command to the motor 85, which should adjust the lift according to the difference between the current attitude and the target attitude. Based on the command, the inverter of the motor 85 adjusts the electrical force supplied from the battery to the motor 85 to change the speed of the motor 85 (and the rotor 79). In addition, the speed adjustment of the motor 85 is performed simultaneously on multiple motors 85, thereby determining the attitude of the aircraft.

[0079] Figure 12 A partial cross-sectional view of the motor 85 in the drive unit 75 is shown. The aforementioned rotating vane 79 is mounted on one end (top of the figure) of the rotating shaft 87 of the motor 85, and a rotor is mounted on the other end (bottom of the figure). The rotor is configured opposite to the stator fixed to the housing 89 and is capable of rotating relative to the stator. Furthermore, the motor 85 can be a brushless motor 85 with an external rotor or a brushless motor 85 with an internal rotor.

[0080] The motor 85 includes a housing (device housing) 89, a rotor (not shown in the figure), a stator (not shown in the figure), an inverter (not shown in the figure), and two bearings 3. In this example, the bearings 3 are inner ring rotating type rolling bearings 3 (more specifically, deep groove ball bearings).

[0081] The outer casing 89 has an outer cylinder 89a and an inner cylinder 89b, with a cooling medium flow path 89c provided between them. By allowing the cooling medium to flow in this cooling medium flow path 89c, excessive temperature rise can be prevented. The material of the outer casing 89 is not particularly limited; for example, ferrous materials, CFRP (carbon fiber reinforced plastic), etc., can be used.

[0082] Bearing 3 rotatably supports rotating shaft 87 within housing 89. Figure 12 In this bearing, the outer diameter of the outer ring 13 of the bearing 3 is the same as the fitting part of the inner circumference of the housing 89, and it is directly fitted onto the housing 89 without passing through the bearing 3 housing or the like. An inner ring spacer 91 and an outer ring spacer 93 are inserted between the two bearings 3, and a preload is applied.

[0083] Furthermore, the structure of the bearing 3 in the drive unit 75 is not limited to Figure 12 Examples. In Figure 12 The example shown is that the rotation shaft 87 of the motor 85 and the rotation shaft of the rotor 79 are set to the same rotation shaft 87, but the rotation shaft 87 of the motor 85 and the rotation shaft of the rotor 79 can also be connected via a transmission mechanism.

[0084] In this case, the bearing 3 of the rotating shaft 87 in the drive unit 75 can be the bearing 3 of the rotating shaft 87 that supports the motor 85, or it can be the bearing 3 of the rotating shaft that supports the rotating blade 79.

[0085] In this embodiment, a bearing device 1 is provided on the bearing 3. The bearing device 1 is equipped with a detection component 5 having the structure described above and a rotation sensor unit 7, which can perform high-precision rotation detection.

[0086] Furthermore, in this embodiment, the bearing 3 is not limited to the deep groove ball bearing listed; for example, an angular contact ball bearing may also be used.

[0087] As described above, preferred embodiments of the present invention have been illustrated with reference to the accompanying drawings. However, various additions, modifications, and deletions can be made without departing from the spirit of the invention. Therefore, such technical solutions are also included within the scope of the present invention.

[0088] Explanation of the labels:

[0089] The number 1 indicates a bearing assembly with an absolute rotation sensor;

[0090] The designation 3 indicates a bearing;

[0091] The number 5 indicates the component being tested;

[0092] The number 7 indicates a sensor unit;

[0093] The designation 11 indicates the inner ring (rotating side raceway ring);

[0094] The designation 13 indicates the outer ring (fixed side raceway ring);

[0095] The designation 15 indicates a rolling element;

[0096] The designation 17 indicates the core iron;

[0097] The number 19 indicates the department being tested;

[0098] The designation 21 indicates a rotary sensor;

[0099] The number 23 indicates the sensor substrate;

[0100] The designation 25 indicates the sensor housing;

[0101] The number 35 indicates the mounting slot;

[0102] The number 37 indicates the guiding surface;

[0103] The designation 61 indicates a resin material;

[0104] The designation 71 indicates an electric vertical take-off and landing (EVTOL) aircraft.

Claims

1. A bearing assembly with an absolute rotation sensor, the bearing assembly with an absolute rotation sensor comprising: The bearing has a rotating side raceway, a fixed side raceway opposite to the rotating side raceway, and rolling elements between the rotating side raceway and the fixed side raceway. The component to be tested is ring-shaped and fixed on the rotating side raceway of the bearing. It has an annular core and a tested part having two rows of magnetic tracks arranged circumferentially across the core. A rotation sensor unit, fixed to the fixed-side raceway ring of the bearing, comprises: a rotation sensor that detects the rotation of the detected part in a non-contact manner; a sensor substrate on which the rotation sensor is mounted; and a sensor housing that covers and mounts the sensor substrate. The aforementioned sensor housing includes a receiving portion for accommodating the aforementioned sensor substrate, comprising a resin material filling the space between the inner wall surface of the receiving portion and the aforementioned sensor substrate, and a cover component covering the end of the receiving portion opposite to the aforementioned bearing, the cover component being detachably mounted to the end of the aforementioned sensor housing.

2. The bearing device with an absolute rotation sensor according to claim 1, wherein, A mounting groove is formed on the sensor housing for inserting the sensor substrate and positioning the sensor substrate in the axial direction and radial direction.

3. The bearing device with an absolute rotation sensor according to claim 1 or 2, wherein, The sensor substrate is positioned with reference to the end of the component being detected.

4. The bearing device with an absolute rotation sensor according to claim 1 or 2, wherein, The protrusion provided on the sensor housing has a guide surface that can guide the component embedded in the protrusion in a direction orthogonal to the axial direction.

5. The bearing device with an absolute rotation sensor according to claim 1 or 2, wherein, The sensor housing is configured such that the sensor substrate can be inserted into the mounting groove from the side opposite to the bearing.

6. The bearing device with an absolute rotation sensor according to claim 1 or 2, wherein, The bearing assembly is mounted on an electric vertical takeoff and landing (EVTOL) aircraft, which includes multiple drive units with rotor blades and motors that rotate the rotor blades, and flies by rotating the rotor blades. The bearing assembly includes a bearing that supports the rotating shaft of the drive unit in a rotatable manner.

7. The bearing device with an absolute rotation sensor according to claim 1 or 2, wherein, With the centers of the raceway grooves of the rotating side raceway and the fixed side raceway aligned, the rotation sensor is mounted on the sensor housing.

8. The bearing device with an absolute rotation sensor according to claim 7, wherein, The axial movement of the aforementioned tested component is controlled to be less than 5 times the radial internal clearance, centered on the bottom of the groove of the aforementioned raceway ring.

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