Sensor arrangement having an angle sensor and a rolling bearing arrangement

Abstract

The invention relates to a sensor arrangement having an angle sensor for the measurement of rotations. The angle sensor is multipolar such that measurements are possible by means of n poles. First of all the angle sensor comprises a sensor ring surrounding an axis of rotation (04) and a material measure which is rotatable relative to said sensor ring. A transmitting coil (27) and a plurality of receiving coils (28) are disposed on the sensor ring. Between the transmitting coil (27) and the receiving coils (28) a magnetic circuit is formed which comprises the material measure and a pot core (17) having two branches (19). To this end the material measure forms a variable reluctance in the magnetic circuit. One of the two branches (19) of the pot core (17) is segment-like, such that said branch comprises ring segments (38). In each case the receiving coils (28) surround one of the ring segments (38). The ring segments (38) each form an arc of a circle having a mean radius (43, 46, 48, 51). According to the invention the mean radii (43, 46, 48, 51) of the circular arcs of two adjacent ring segments (42, 49; 44, 42; 47, 44; 49, 47) in each case have an angle (ε, ζ, η, θ) relative to one another which is simply the integral or a multiple of the nth fraction of the right angle. The invention further relates to a rolling bearing arrangement (1).

Claims

1. A sensor arrangement comprising: an angle sensor including a sensor ring surrounding a rotation axis and a material measure rotatable relative thereto; at least one transmitter coil and multiple receiver coils being situated on the sensor ring, a signal being transmittable between the transmitter coil and the receiver coils via a magnetic circuit, and the rotatable material measure forming a variable reluctance in the magnetic circuit; the transmitter coil being situated in an annular pot core forming one part of the magnetic circuit; the material measure being designed as a ring which closes the magnetic circuit between two annular legs of the pot core; the receiver coils each being situated partially within and partially outside the pot core, one of the annular legs of the pot core having a segmented design, so that the one annular leg includes ring segments, the receiver coils each surrounding at least one of the ring segments; and the ring segments each forming a circular arc with respect to the rotation axis and spaced apart in a circumferential direction, at least some of the ring segments being spaced apart unevenly in the circumferential direction, a center radius of the particular circular arc each forming an axis of symmetry of the particular circular arc; the angle sensor having a multipolar design for a measurement over n poles, the center radii of the circular arcs of two adjacent ring segments each having an angle with respect to each other, the angle being the integral or a multiple of the nth fraction of the right angle.

2. The sensor arrangement as recited in claim 1 wherein the center radius of the circular arc of a first of the ring segments has an angle (α) of (45°+a.Math.360°)/n with respect to a reference angle position, a being a natural number; the center radius of the circular arc of a second of the ring segments having an angle (β) of (225°+b.Math.360°)/n with respect to the reference angle position, b being a natural number; the center radius of the circular arc of a third of the ring segments having an angle (γ) of −(225°+c.Math.360°)/n with respect to the reference angle position, c being a natural number; and the center radius of the circular arc of a fourth of the ring segments having an angle (σ) of −(45°+d.Math.360°)/n with respect to the reference angle position, d being a natural number n being the number of n poles.

3. The sensor arrangement as recited in claim 2 wherein the center radius of the circular arc of the first ring segment is situated in a first quadrant with respect to the reference angle position; the center radius of the circular arc of the second ring segment being situated in a second quadrant with respect to the reference angle position; the center radius of the circular arc of the third ring segment being situated in a third quadrant with respect to the reference angle position; and the center radius of the circular arc of a fourth ring segment being situated in the fourth quadrant with respect to the reference angle position.

4. The sensor arrangement as recited in claim 1 wherein the receiver coils are formed by sine coils and cosine coils.

5. The sensor arrangement as recited in claim 4 wherein the sine coils are provided in pairs, each of the pairs of sine coils including a positive sine coil and a negative sine coil, signals measurable with the aid of the positive sine coils and signals measurable with the aid of the negative sine coil during the rotation of the material measure with respect to the sensor ring having an electrical period representing a rotation angle of 360°/n between the material measure and the sensor ring; the cosine coils furthermore also being provided in pairs, each of the pairs of cosine coils including a positive cosine coil and a negative cosine coil, signals measurable with the aid of the positive cosine coil and signals measurable with the aid of the negative cosine coil during the rotation of the material measure with respect to the sensor ring having an electrical period which represents a rotation angle of 360°/n between the material measure and the sensor ring.

6. The sensor arrangement as recited in claim 5 wherein the positive sine coil surrounds a first ring segment; the negative sine coil surrounding second ring segment; the negative cosine coil surrounding a third ring segment; and the positive cosine coil surrounding a fourth ring segment and wherein the center radius of the circular arc of the first ring segment is situated in a first quadrant with respect to the reference angle position; the center radius of the circular arc of the second ring segment being situated in a second quadrant with respect to the reference angle position; the center radius of the circular arc of the third ring segment being situated in a third quadrant with respect to the reference angle position; and the center radius of the circular arc of a fourth ring segment being situated in the fourth quadrant with respect to the reference angle position.

7. The sensor arrangement as recited in claim 1 wherein the circular arcs of the ring segment each have a center point angle smaller or equal to the nth fraction of the right angle.

8. The sensor arrangement as recited in claim 1 wherein each of the receiver coils surrounds an m number of ring segments, where m≦max(1; |n/4|).

9. The sensor arrangement as recited in claim 1 wherein the material measure has an annular cross section perpendicular to the rotation axis, the material measure having n circumferential sections of equal length circumferentially along the annular shape, the size of a ring width within each of the n circumferential sections increasing from a minimum ring width to a maximum ring width and decreasing back to the minimum ring width.

10. A rolling bearing arrangement comprising: a rolling bearing including a first bearing ring and a second bearing ring rotatable with respect to the first bearing ring; and a sensor arrangement as recited in claim 1, the sensor ring being coupled with the first bearing ring, and the material measure being rotatably fixedly connected to the second bearing ring.

11. The sensor arrangement as recited in claim 1 wherein the material measure has an annular cross section perpendicular to the rotation axis, the material measure having at least two circumferential sections of equal length circumferentially along the annular shape, the size of a ring width within each of the circumferential sections having a maximum, the at least two circumferential sections meeting at a minimum of the right width.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: shows a p.c. board and four ring segments of one preferred specific embodiment of the sensor arrangement according to the present invention;

(2) FIG. 2: shows a perspective cross-sectional representation of a generic rolling bearing arrangement according to the prior art;

(3) FIG. 3: shows a cross-sectional representation of the rolling bearing arrangement illustrated in FIG. 2;

(4) FIG. 4: shows a detailed representation of a p.c. board illustrated in FIG. 2;

(5) FIG. 5: shows a p.c. board and four ring segments of one preferred specific embodiment of the sensor arrangement according to the present invention, including a quadripolar angle sensor;

(6) FIG. 6: shows a p.c. board and four ring segments of one preferred specific embodiment of the sensor arrangement according to the present invention, including an eight-pole angle sensor;

(7) FIG. 7: shows a p.c. board and eight ring segments of one preferred specific embodiment of the sensor arrangement according to the present invention, including a quadripolar angle sensor;

(8) FIG. 8: shows a p.c. board and four ring segments of a modified specific embodiment of the sensor arrangement according to the present invention, including an eight-pole angle sensor;

(9) FIG. 9: shows a material measure, which is known from the prior art for the rolling bearing arrangement illustrated in FIG. 2;

(10) FIG. 10: shows a detailed view of the material measure illustrated in FIG. 2;

(11) FIG. 11: shows a material measure of a preferred specific embodiment of the sensor arrangement according to the present invention; and

(12) FIG. 12: shows a material measure of a particularly preferred specific embodiment of the sensor arrangement according to the present invention.

DETAILED DESCRIPTION

(13) FIG. 1 shows p.c. board 26 and four ring segments 38 in one preferred specific embodiment of the sensor arrangement according to the present invention. This specific embodiment of the sensor arrangement according to the present invention is similar in structure to angle sensor 02 illustrated in FIGS. 2 through 4 and differs only in the design of material measure 14 and ring segments 38 (see FIG. 4). The sensor arrangement according to the present invention also preferably provides a rolling bearing arrangement together with rolling bearing 01 illustrated in FIG. 2.

(14) The embodiment of ring segments 38 illustrated in FIG. 1 results in the fact that the sensor arrangement represents a bipolar angle sensor in which n=2. The bipolar angle sensor is used for the absolute measurement of angles in the range from 0° to 360°/n; i.e., from 0° to 180°.

(15) The representation shown in FIG. 1 is comparable to the representation in FIG. 4, which shows p.c. board 26, including four ring segments 38, in a monopolar design according to the prior art. Transmitter coil 27 and four receiver coils 28 are therefore shown in the same manner.

(16) To illustrate the different angle positions of ring segments 38, a reference angle position 41 is marked to be able to indicate angles with respect to rotation axis 04. In the illustrated specific embodiment, reference angle position 41 is situated symmetrically between receiver coils 28, so that reference angle position 41 simultaneously represents a reference position for the angle measurement using the sensor arrangement according to the present invention. As a result, reference angle position 41 corresponds to measured value 0° of the sensor arrangement. However, the reference angle position may also be selected at a different angle position. In particular the reference angle position may differ from reference angle position 0° of the sensor arrangement.

(17) A first ring segment 42 of four ring segments 38 includes a center radius 43, which has an angle α with respect to reference angle position 41. A second ring segment 44 of four ring segments 38 includes a center radius 46, which has an angle β with respect to reference angle position 41. A third ring segment 47 of four ring segments 38 includes a center radius 48, which has an angle γ with respect to reference angle position 41. A fourth ring segment 49 of four ring segments 38 includes a center radius 51, which has an angle δ with respect to reference angle position 41.

(18) According to the present invention, angle α has the size (45°+a.Math.360°)/n, where n=2 applies to the illustrated bipolar sensor. According to the present invention, angle β equals (225°+b.Math.360°)/n. According to the present invention, angle γ equals −(225°+c.Math.360°)/n. According to the present invention, angle δ equals −(45°+d.Math.360°)/n. Factors a, b, c and d are natural numbers and are greater than or equal to zero.

(19) An angle ε stretches between center radius 43 of first ring segment 42 and center radius 51 of fourth ring segment 49. An angle ζ stretches between center radius 46 of second ring segment 44 and center radius 43 of first ring segment 42. An angle η stretches between center radius 48 of third ring segment 47 and center radius 46 of second ring segment 44. An angle θ stretches between center radius 51 of fourth ring segment 49 and center radius 48 of third ring segment 47. Angles ε, ζ, η and θ are each equal to an integral or a multiple of the nth fraction of the right angle, n=2 applying to the illustrated bipolar sensor.

(20) Four ring segments 38 each have the shape of a circular arc. Circular arcs each have a center point angle λ, which is illustrated on the basis of the example of second ring segment 44. Center point angle λ may be up to 90°/n in size. In the practical embodiment, the center point angle of ring segments 38 is reduced in many cases, in particular due to the extension of receiver coils 28.

(21) Receiver coil 28 surrounding first ring segment 42 is a positive sine coil. Receiver coil 28 surrounding second ring segment 44 is a negative sine coil. Receiver coil 28 surrounding third ring segment 47 is a negative cosine coil. Receiver coil 28 surrounding fourth ring segment 49 is a positive cosine coil.

(22) The illustrated embodiment of p.c. board 26, including four ring segments 38, for providing a bipolar angle sensor of the sensor arrangement according to the present invention interacts with material measure 14, as illustrated in different embodiments in FIGS. 11 and 12.

(23) FIG. 5 shows p.c. board 26 and four ring segments 38 in one preferred specific embodiment of the sensor arrangement according to the present invention, including a quadripolar angle sensor. This embodiment is similar to the embodiment illustrated in FIG. 1, with the provision that n=4. Incidentally, other values may be selected for factors a, b, c and d.

(24) FIG. 6 shows p.c. board 26 and four ring segments 38 in another preferred specific embodiment of the sensor arrangement according to the present invention, including an eight-pole angle sensor. This embodiment is similar to the embodiment illustrated in FIG. 1, with the provision that n=8. Incidentally, other values may be selected for factors a, b, c and d.

(25) FIG. 7 shows p.c. board 26 and eight ring segments 38 in another preferred specific embodiment of the sensor arrangement according to the present invention, including a quadripolar angle sensor. This specific embodiment includes eight of receiver coils 28 and eight of ring segments 38. Consequently, this specific embodiment includes, in addition to ring segments 42, 44, 47, 49 illustrated in FIG. 1, a fifth ring segment 53 of ring segments 38, which has a center radius 54. A sixth ring segment 56 of ring segments 38 has a center radius 57. A seventh ring segment 58 of ring segments 38 has a center radius 59. An eighth ring segment 61 of ring segments 38 has a center radius 62. The arrangement of first four ring segments 42, 44, 47, 49 is similar to the arrangement illustrated in FIG. 1, with the provision that n=4, factors a, b, c and d being selected accordingly. Fifth ring segment 53 is offset 180° with respect to first ring segment 42. Sixth ring segment 56 is offset 180° with respect to second ring segment 44. Seventh ring segment 58 is offset 180° with respect to third ring segment 47. Eighth ring segment 61 is offset 180° with respect to fourth ring segment 49.

(26) Receiver coil 28 surrounding fifth ring segment 53 is formed by a positive sine coil. Receiver coil 28 surrounding sixth ring segment 56 is formed by a negative sine coil. Receiver coil 28 surrounding seventh ring segment 58 is formed by a negative cosine coil. Receiver coil 28 surrounding eighth ring segment 61 is formed by a positive cosine coil.

(27) FIG. 8 shows p.c. board 26 and four ring segments 38 in a modified specific embodiment of the sensor arrangement according to the present invention, including an eight-pole angle sensor. The arrangement of four ring segments 38 with respect to reference angle position 41 is similar to the representation shown in FIG. 1, with the provision that n=8. Another difference is that reference angle position 41 does not coincide with a line of symmetry of p.c. board 26 but has an offset angle σ thereto. Offset angle σ is irrelevant for the function of the sensor arrangement according to the present invention.

(28) FIG. 11 shows material measure 14 in one particularly preferred specific embodiment of the sensor arrangement according to the present invention. Material measure 14 is a material measure of a bipolar angle sensor. The view in FIG. 11 is similar to the views in FIGS. 9 and 10, which show material measures 14 according to the prior art.

(29) Material measure 14 has an eccentric design, a ring width of annular material measure 14 having two minima and two maxima along its circumference. One of the maxima and one of the minima are each situated in a circumferential section of 180°.

(30) The material measure in specific embodiments of the sensor arrangement according to the present invention for other numbers of poles n correspondingly have n of the maxima and n of the minima of the ring width, one of the maxima and one of the minima being each situated in a circumferential section of 360°/n.

(31) FIG. 12 shows material measure 14 in one particularly preferred specific embodiment of the sensor arrangement according to the present invention. Material measure 14 illustrated in FIG. 12 differs from the material measure illustrated in FIG. 11 in that it has a double eccentric design. While the eccentricity of the material measure illustrated in FIG. 11 is effectuated only by varying the outer radius of annular material measure 14, in the material measure illustrated in FIG. 12, the eccentricity is effectuated by varying the outer radius as well as by varying the inner radius of the annular shape of material measure 14.

LIST OF REFERENCE NUMERALS

(32) 01 rolling bearing

(33) 02 angle sensor

(34) 03 inner ring

(35) 04 rotation axis

(36) 05 -

(37) 06 outer ring

(38) 07 rolling element

(39) 08 cage

(40) 09 sealing washer

(41) 10 -

(42) 11 sensor ring

(43) 12 holding element

(44) 13 circumferential groove in outer ring

(45) 14 material measure

(46) 15 -

(47) 16 circumferential groove in inner ring

(48) 17 U-shaped pot core

(49) 18 inner U-leg

(50) 19 outer U-leg

(51) 20 -

(52) 21 U-base

(53) 22 inner supporting ring

(54) 23 outer supporting ring

(55) 24 annular space

(56) 25 -

(57) 26 p.c. board

(58) 27 transmitter coil

(59) 28 receiver coils

(60) 29 cable

(61) 30 -

(62) 31 cable holder

(63) 32 recess in outer supporting ring

(64) 33 -

(65) 34 -

(66) 35 -

(67) 36 printed conductors

(68) 37 openings in p.c. board

(69) 38 ring segments

(70) 39 -

(71) 40 -

(72) 41 reference angle position

(73) 42 first ring segment

(74) 43 center radius of first ring segment

(75) 44 second ring segment

(76) 45 -

(77) 46 center radius of second ring segment

(78) 47 third ring segment

(79) 48 center radius of third ring segment

(80) 49 fourth ring segment

(81) 50 -

(82) 51 center radius of fourth ring segment

(83) 52 -

(84) 53 fifth ring segment

(85) 54 center radius of fifth ring segment

(86) 55 -

(87) 56 sixth ring segment

(88) 57 center radius of sixth ring segment

(89) 58 seventh ring segment

(90) 59 center radius of seventh ring segment

(91) 60 -

(92) 61 eighth ring segment

(93) 62 center radius of eighth ring segment