Mounted assembly, method for manufacturing the mounted assembly, and electronically commutated motor with the mounted assembly

Abstract

The present invention relates to an assembly (10) comprising a machine shaft (12), a second rolling bearing (20) having an inner ring (22) and an outer ring (24) for rotatably supporting the machine shaft (12) in a housing block (16), and a signal generator (40) of a rotor position sensor having a generator element (44) and a holding cup (42) for electrically detecting the rotation angle of the machine shaft (12). 【Means for solving the problem】 An annular gap exists between a fixed portion (46) of the holding cup (42) and the circumference of the machine shaft (12), and a fastening ring (52) is inserted into this annular gap. The signal generator (40) is attached to the machine shaft (12) by this fastening ring so as to be non-rotatable and axially immovable. According to the present invention, the fastening ring (52) projects axially from the holding cup (42) by an end of the fastening ring, and is axially supported by the inner ring of the rolling bearing (20) by this projecting end. The present invention further relates to a method of assembling the assembly (10) and an electronic rectifier motor equipped with the assembly (10).

Description

[Technical Field]

[0001] The invention relates to an assembly according to the features of the preamble of claim 1, to a method for manufacturing an assembly according to the features of the preamble of claim 7, and to an electronically commutated motor according to the features of the preamble of claim 8. [Background technology]

[0002] Attribute-corresponding mounting assemblies are known from the prior art, for example, US Pat. No. 5,629,999 discloses an electronically commutated machine with such a mounting assembly, which is provided as a drive unit for a brake pressure generator of an electronically slip-controllable braking system of a motor vehicle.

[0003] In this known machine, a signal generator is fixedly mounted on one end of the machine shaft so that it cannot rotate. The signal generator, which rotates with the machine shaft, together with a signal receiver, which is fixedly positioned in the housing block, form a sensor system for detecting the rotational position of the machine shaft. The position signal is transferred to an electronic control unit and evaluated there. For example, this position signal can be used for optimal electrical control of the stator of the electric machine and / or to determine the working distance of a piston of a pressure generator, which is driven by the machine shaft, possibly via a downstream transmission. From the distance traveled by the piston, the volume of brake fluid displaced into the connected brake circuit can be determined, from which the expected brake pressure in the brake circuit can be determined.

[0004] Patent document 1 proposes a force-locking shaft-hub connection using a clamping or tolerance ring to connect a signal generator to a machine shaft in a non-rotatable and axially immobile manner. The tolerance ring is inserted in an annular gap between the outer periphery of the machine shaft and the inner periphery of a retaining cup of the signal generator, which is fitted onto the machine shaft. The latter carries a magnet as a generator element. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] German Patent Application Publication No. 102020204831 Summary of the Invention

[0006] The present invention improves on this known assembly in that the tolerance ring is also used to axially urge the raceways of a rolling bearing, which is provided for supporting the machine shaft. To this end, the clamping ring or tolerance ring projects axially at one end from the clamping portion of the signal generator's retaining cup and is supported by this projecting end on the inner race of the rolling bearing. The clamping force of the rolling bearing is provided by a spring element that is arranged on the opposite side of the rolling bearing and applies a load to the assigned outer race of the rolling bearing.

[0007] The proposed support of the fastening ring or tolerance ring on the inner ring of the rolling bearing makes it possible to omit axial support of the fastening ring or tolerance ring to prevent movement relative to the machine shaft when assembling the signal generator. This is particularly advantageous when the available construction space makes the use of support tools difficult or even prohibits them, as is common in automotive components. The signal generator can be joined in a concealed state, i.e., without measures to monitor such undesirable relative movement between the tolerance ring and the machine shaft. In the assembled state, the rolling bearing is fixed in the longitudinal direction of the shaft, i.e., axially, between the fastening ring or tolerance ring and a shaft shoulder provided on the machine shaft. This eliminates the need for additional components, such as a snap ring.

[0008] Further advantages or advantageous developments of the invention emerge from the dependent claims or the following description. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a longitudinal cross-sectional view of the assembly. [Figure 2a] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2b] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2c] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2d] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2e] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2f] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2g] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2h] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2i] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2j] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. [Figure 2k] 1A-1C illustrate a method for manufacturing an assembled assembly by successive process steps. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the invention is illustrated in the drawing and explained in more detail in the following description, which includes a number of figures.

[0011] According to FIG. 1, the assembly 10 of the present invention comprises a machine shaft 12 rotatably supported in a shaft bore 14 of a housing block 16. The support is provided by at least two rolling bearings, of which only one, the so-called second rolling bearing 20, is shown in FIG. 1. This second rolling bearing 20 is illustratively formed as a double-sealed ball bearing with an inner ring 22, an outer ring 24, and balls 26 housed in the raceway between the rings. The second rolling bearing 20 is arranged in a cylindrical portion of a bearing receptacle 30 of the housing block 16, which opens conically toward the end of the machine shaft 12. An electronic control unit 28 is attached to the housing block 16, and the end of the machine shaft 12 extends into this electronic control unit. A signal receiver (38) is fixedly positioned on the electronic control unit (28) opposite the opening of the shaft hole (14).

[0012] The bearing receptacle 30 terminates on the opposite side of the opening with a support shoulder 32 formed perpendicular to the longitudinal axis of the shaft. This support shoulder 32 serves as a first axial support for a spring element 34, exemplarily formed as a wave spring washer. A second axial support for the spring element 34 forms the side surface of the outer ring 24 of the second rolling bearing 20. In the assembled state, the spring element 34 is arranged between the two aforementioned supports with an axial bias.

[0013] The machine shaft 12 is initially stepped at a right angle on its outer diameter, forming a shaft shoulder 18 accordingly. A first shaft section with a smaller outer diameter is formed at the end of the machine shaft 12. A second shaft section with a larger outer diameter extends through a ring-shaped spring element 34 and further into the shaft bore 14. A second rolling bearing 20 is accommodated in the first shaft section with a smaller diameter by the inner diameter of its inner ring 22. The second rolling bearing 20 abuts against the shaft shoulder 18 with the lateral surface of its inner ring 22. A loose fit exists between the outer diameter of the outer ring 24 of the second rolling bearing 20 and the inner diameter of the bearing receptacle 30, as well as between the inner diameter of the inner ring 22 of the second rolling bearing 20 and the outer diameter of the machine shaft 12. The second rolling bearing 20 is therefore arranged in the bearing receptacle 30 so as to be displaceable relative to the machine shaft 12 and relative to the housing block 16.

[0014] The machine shaft 12 projects from the second rolling bearing 20 with its first, smaller-diameter shaft portion toward the opening of the shaft bore 14. This projecting shaft portion of the machine shaft 12 forms a fastening part 36 for a signal generator 40 fixed to the machine shaft 12. To this end, the signal generator 40 is sleeve-shaped and comprises a retaining cup 42 that projects beyond the end of the machine shaft and a magnet 44 as a generator element carried by the retaining cup 42. The signal generator 40, in cooperation with a signal receiver 38 in the electronic control device 28, forms a sensor system for detecting the rotation angle of the machine shaft 12.

[0015] The signal generator 40 has a retaining cup 42, which is sleeve-shaped and open on both sides and is divided into a fixed part 46 at its end facing the rolling bearing and a generator receptacle 48 for the magnet 44 at the opposite end of the retaining cup 42 facing the control device. The retaining cup 42 has a smaller inner diameter in the region of the fixed part 46 than in the region of the generator receptacle 48, so that the magnet 44 carried by the generator receptacle 48 projects radially beyond the end face of the machine shaft 12. The magnet 44 directly faces the signal receiver 38 in the electronic control device 38.

[0016] A push-in collar 50 is integrally formed on the end of the fixed part 36 of the retaining cup 42 facing the rolling bearing, and projects perpendicularly from the retaining cup 42. In the end position of the retaining cup 42 shown in the drawing, there is a predetermined axial distance between this push-in collar 50 and the facing side of the second rolling bearing 20, i.e., the retaining cup 42 and the second rolling bearing 20 do not come into contact with each other.

[0017] The signal generator 40 is secured to the machine shaft 12 using a clamping ring 52. The clamping ring 52 fits into the annular gap between the outer diameter of the first, smaller diameter shaft section of the machine shaft 12 and the inner diameter of the fixed portion 46 of the retaining cup 42. The clamping ring 52 is also known as a tolerance ring and is available as a closed, open, or slotted ring.

[0018] According to the present invention, the fastening ring (52) protrudes axially from the fixed portion (46) of the retaining cup (42) with its end facing the second rolling bearing (20) and is axially supported on the side surface of the inner ring (22) of the second rolling bearing (20).

[0019] By forming raceways for the rolling elements / balls 26 on both the inner ring 22 and the outer ring 24 of the second rolling bearing 20, the two rings are connected to one another in a positive manner via the balls 26 and in an axially displaceable manner due to the unavoidable bearing clearance caused by manufacturing. A spring element 34 exerts a biasing force on the outer ring 24 of the rolling bearing 20, thereby clamping the two rings of the rolling bearing 20 together. The clamped support of the machine shaft 12 in the housing block 16 ensures particularly quiet and wear-resistant operation of the machine equipped therewith.

[0020] When manufacturing the assembled unit, it is possible to dispense with a support tool for securely fixing the position of the clamping ring or tolerance ring 52 on the machine shaft 12 during assembly of the signal generator 40. The clamping ring 52 abuts axially against the inner ring 22 of the second rolling bearing 20, preventing any relative movement between the clamping ring 52 and the machine shaft 12 in the axial direction or in the longitudinal direction of the shaft, allowing the retaining cup 42 of the signal generator 40 to be fitted onto the clamping ring 52 in a concealed manner.

[0021] Figure 2 shows the manufacture of an electric motor equipped with an assembly assembly (10) according to the invention. The individual sub-figures 2a to 2k show the individual successive assembly steps in a simplified schematic manner. Corresponding parts in the sub-figures of Figures 1 and 2 are consistently given the same reference numerals.

[0022] Figure 2a shows the initial state at the start of the assembly method. In this initial state, a housing block 16 is provided, which has a shaft bore 14 extending therethrough. An electric machine, in this example an electric motor, with a stator housing 60 is attached to one of the outer surfaces of the housing block 16, for example by a screw connection (not shown). The stator housing 60 houses a stator 62 and a rotor 64 rotatably accommodated within the stator 62. The rotor 64 is rigidly connected to the machine shaft 12, which extends into the shaft bore 14. The machine shaft 12 protrudes from the housing block 16 on the opposite side of the rotor. This side of the housing block 16 is provided for mounting an electronic control unit (reference numeral 28; Figure 1).

[0023] A first rolling or ball bearing 66 is provided for rotatably supporting the machine shaft 12 or a rotor 64 firmly connected thereto in the housing block 16. The inner ring 68 of this first rolling bearing 66 is firmly pressed against the machine shaft 12, while the outer ring 70 of the first rolling bearing 66 is firmly pressed, with its end facing the rotor 64, circumferentially into a first bearing seat 72 in a housing cover 74 that covers the stator housing 60, and, with its end opposite the rotor 64, also circumferentially into a second bearing seat 76 on the outside of the housing block 16.

[0024] An output element 78 is attached to the part of the machine shaft 12 journalled inside the shaft bore 14. In this case, this may be a spindle nut, a gear, an eccentric, a cam, etc. The output element 78 and the machine shaft 12 may be made in one piece or alternatively may be separate parts rigidly connected to each other.

[0025] The end of the shaft bore (14) of the machine housing facing the stator housing (69) has a support shoulder (32) facing in the direction of the opening of this shaft bore (14).

[0026] According to Figure 2b, a spring element 34, which is ring-shaped and surrounds the machine shaft 12, is placed in the shaft bore 14. In the assembled state, this spring element 34 rests on a support shoulder 32 formed inside the shaft bore 14.

[0027] Figure 2c shows a second rolling or ball bearing (20), which is fitted onto the machine shaft (12) by its inner ring (22) or, according to Figure 2d, by the leading flank of its outer ring (24) until it rests on the spring element (32). The second rolling bearing (20) rests on its circumferential side against the wall of the bearing receptacle (30). Not visible in Figures 2c and 2d is a first clearance fit between the inner ring (22) of the second rolling bearing (20) and the machine shaft (12), or a second clearance fit between the outer ring (24) of the second rolling bearing (20) and the wall of the bearing receptacle (30).

[0028] 2e, the clamping ring or tolerance ring 52 is assembled onto the machine shaft 12. For this purpose, the clamping ring 52 is first threaded onto the free end of the machine shaft 12 and then displaced along the shaft circumference until its leading end contacts the inner ring 22 of the second rolling bearing 20. For this purpose, a slight axial force must be applied in the direction of the longitudinal axis of the shaft, since the fit between the clamping ring 52 and the machine shaft 12 is designed as a loose or transition fit.

[0029] 2f, the magnet 44 of the signal generator 40 is then inserted into the generator receptacle 48 of the retaining cup 42 provided for this purpose and attached, for example, by gluing or crimping, to the retaining cup 42. The pre-assembled retaining cup 42-magnet 44 unit is then centered on the outer periphery of the clamping ring 52 and at least partially pressed against the clamping or tolerance ring 52 using a pressing tool 80 (FIG. 2g). For this purpose, the pressing tool 80 acts on the back surface of the pressing collar 50, which projects radially from the retaining cup 42 when viewed in the pressing direction.

[0030] As the retaining cup 42 and the clamping ring 52 begin to overlap, the pressing force increases, causing the clamping ring 52 to move relative to the machine shaft 12 toward the inside of the shaft bore 14, and in so doing, the spring element 34, located between the support shoulder 32 of the housing block 16 and the outer ring 24 of the second rolling bearing 20, is biased to move the abutting second rolling bearing 20 forward. The side of the inner ring 22 of this second rolling bearing 20 mechanically abuts against the shaft shoulder 18 of the machine shaft 12, causing the second rolling bearing 20 to reach its end position (Figure 2h).

[0031] 2i, the retaining cup 42 and magnet 44 unit is then moved further relative to the clamping ring 52 by the continuing pressing force until maximum overlap between the retaining cup 42 and the clamping ring 52 is achieved, thereby completing the pressing process of the signal generator 40. The clamping ring 52 is then radially biased by the retaining cup 42 and is firmly secured to the machine shaft 12 due to this bias.

[0032] When the signal generator 40 is pressed against the clamping ring 52, a pressing force acts on the inner ring 22 of the second rolling bearing 20 via the clamping ring 52. In the opposite axial direction, a force is then applied to the assigned outer ring 24 of the second rolling bearing 20 by a spring element 34 supported on a support shoulder 32 of the housing block 16. These opposing forces on the respective raceways of the second rolling bearing 20 clamp the raceways together, thereby reducing the initial bearing clearance, i.e., the clearance between the rolling elements or balls 26 in the raceways of the inner ring 22 or outer ring 24, to at least approximately zero. The inner ring 22 of the second rolling bearing 20 then projects further into the shaft bore 14 than the outer ring 24.

[0033] 2k, the pressing process of the signal generator 40 onto the clamping ring 52 is completed. The pressing tool 80 is unloaded and removed from the retaining cup 42. The biased spring element 34, which applies a load to the outer ring 24 of the second rolling bearing 20, then relaxes. The outer ring 24 of the second rolling bearing 20 thus moves in the assigned bearing receptacle 30 toward the opening of the shaft bore 14, thereby moving the assigned inner ring 22 along with it while maintaining the mutual clamping of the bearing rings.

[0034] The latter is tightly sandwiched between the clamping ring (52) and the shaft shoulder (18) of the machine shaft (12), thereby transmitting the above-mentioned axial movement of the outer ring (24) ultimately to the entire machine shaft (20).

[0035] As described above, the inner ring (68) of the first rolling bearing (66) arranged on the rotor side is firmly pressed against the machine shaft (12), so that this inner ring (68) also follows the axial movement of the machine shaft (12) and thereby moves relative to the outer ring (70), which is also firmly accommodated in the bearing seats (72, 74).

[0036] The result is thus a bearing of the machine shaft 12 in which the races 22, 24; 68, 70 of the two rolling bearings 20; 66 are clamped against each other. Such a biased bearing of the machine shaft 12 in the housing block 16 is particularly characterized by low noise and wear resistance of the machine equipped with this assembly unit 10.

[0037] Naturally, modifications and additions can be made to the above-described embodiment without departing from the spirit of the invention as claimed in the independent claims.

[0038] In this connection, it is to be mentioned that the invention is not limited to application in vehicle braking systems, but can be implemented in general in any kind of machine, motor or generator. As is known, in the case of a motor, the electrical energy supplied to the stator (62) can be converted into a mechanical torque which can drive a consumer by means of the machine shaft (12) via the output element (78), while in the case of a generator, the rotational motion imposed on the machine shaft (12) is used to generate electrical energy. [Explanation of symbols]

[0039] 10 Assembly 12 Machine Shaft 14 Shaft hole 16 Housing Block 18 Shaft Shoulder 20 Second rolling bearing 22 Inner Circle 24 outer ring 26 balls 28 Control Device 30 Bearing housing 32 Support Shoulder 34 Spring elements 36 Fastening part 38 Signal Receiver 40 Signal Generator 42 Retaining Cup 44 Magnet, generator element 46 Fixed part 48 Generator housing 50 Closet brim 52 Fastening ring, tolerance ring 60 Stator housing 62 Stator 64 rotors 66 First rolling bearing 68 Inner Circle 70 outer ring 72 First bearing seat 74 Housing cover 76 Second bearing seat 78 Output Elements 80 Pressing tool

Claims

1. a machine shaft (12) drivable for rotational movement; at least one rolling bearing (20) for rotatably supporting the machine shaft (12) in a housing block (16), the rolling bearing having an inner ring (22) carrying the machine shaft (12) and an outer ring (24) assigned to the inner ring and accommodated in a bearing receptacle (30) of the housing block (16); a signal generator (40) of a position detection sensor system for detecting a rotation angle of the machine shaft (12), the signal generator having a retaining cup (42) and a generator element (44) arranged in the retaining cup (42); a fastening ring (52) disposed in an annular gap between an inner periphery of the retaining cup (42) and an outer periphery of the machine shaft (12), for fixing the signal generator (40) to the tip end of the machine shaft (12) so as to be non-rotatable and axially immovable, The fastening ring (52) has one end that protrudes axially from the retaining cup (42) of the signal generator (40), and is axially supported by the protruding end on a side surface of the inner ring (22) of the rolling bearing (20).

2. 2. The assembly according to claim 1, wherein the bearing accommodating portion (30) of the housing block (16) is located on the opposite side of the opening of the shaft hole (14) and forms a support shoulder (32) on which a spring element (34) is axially supported, the spring element (34) applying an axial force to the outer ring (24) of the rolling bearing (20) in a direction opposite to the support force with which the fastening ring (52) is supported on the side surface of the inner ring (22) of the rolling bearing (20).

3. 3. The mounting assembly according to claim 2, wherein said spring element (34) is a wave spring washer.

4. 3. The assembly according to claim 1, wherein the retaining cup (42) is a sleeve-like, open-ended member divided into a fixed portion (46) at the tip and a generator housing portion (48) for the generator element (44) at the tip, the generator housing portion (48) being located on the opposite side of the tip, and wherein the retaining cup (42) has a smaller inner diameter in the region of the fixed portion (46) than in the region of the generator housing portion (48).

5. 5. The assembly of claim 4, wherein the generator element (44) includes a magnet, the magnet axially abutting the transition from the generator housing portion (48) to the fixed portion (46) inside the retaining cup (42).

6. The inner ring (22) of a second rolling bearing (20) of the at least one rolling bearing is arranged on the machine shaft (12) by a clearance fit; 4. The assembly according to claim 2 or 3, characterized in that the outer ring (24) of the rolling bearing (20) is accommodated in the assigned bearing accommodating portion (30) of the housing block (16) with a loose fit.

7. A method for manufacturing a mounting assembly according to any one of the features of claim 1 or 2, comprising the steps of: providing a housing block (16) having a shaft bore (14), a bearing receptacle (30), and an electric machine mounted in the housing block (16) and having a machine shaft (12) protruding into the shaft bore (14) of the housing block (16); assembling a ring-shaped spring element (34) into the bearing receptacle (30) of the housing block (16) until the spring element (34) rests on a support shoulder (32) formed on the housing block (16); a step of fitting a rolling bearing (20) onto the machine shaft (12) by means of an inner ring (22), and a step of inserting a second rolling bearing (20) of the at least one rolling bearing into the bearing receiving portion (30) of the housing block (16) until the second rolling bearing (20) abuts the spring element (34) by means of a side surface of the outer ring (24); fitting the fastening ring (52) onto the machine shaft (12) until the leading end of the fastening ring (52) abuts axially against the inner ring (22) of the rolling bearing (20); applying an axial force to the signal generator (40) to press the signal generator (40) against the circumference of the fastening ring (52), so that the fastening ring (52) together with the second rolling bearing (20) is displaced along the machine shaft (12) and the spring element (34) is biased in the axial direction, and the rolling bearing (20) abuts against a shaft shoulder (18) formed on the machine shaft (12); and displacing the signal generator (40) relative to the fastening ring (52) to an end position where maximum overlap between the signal generator (40) and the fastening ring (52) is achieved and the fastening ring (52) is supported on the inner ring (22) of the second rolling bearing (20) by an end of the signal generator (40) protruding from the retaining cup (42).

8. 3. An electronically commutated motor, in particular for a controllable drive of a brake pressure generator of an electronically slip-controllable braking system of a motor vehicle, characterized in that the electronically commutated motor comprises an assembly (10) according to claim 1 or 2.

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