Assembly assembly, method for producing assembly assembly, and electronically commutated motor having assembly assembly

Abstract

The 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 the housing block (16); the invention relates to a signal generator (40) for a rotor position sensor for electrically detecting the angle of rotation of a machine shaft (12), comprising a generator element (44) and a holding cup (42). An annular gap is present between the fastening section (46) of the retaining cup (42) and the circumference of the machine shaft (12), in which annular gap a fastening ring (52) is located, by means of which the signal generator (40) is fastened to the machine shaft (12) in a rotationally fixed and axially fixed manner. According to the invention, one end of the fastening ring (52) protrudes axially out of the retaining cup (42) and the protruding end is supported axially on the inner ring of the rolling bearing (20). The invention further relates to a method for assembling the assembly (10) and to an electronically commutated motor equipped with the assembly (10).

Description

Technical Field

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

[0002] Common assembly kits are known in the prior art. For example, document DE 10 2020 204831 A1 discloses an electronically commutated machine having such an assembly kit, which is provided as a drive device for a brake pressure generator of an electronically slip-controlled brake device of a motor vehicle.

[0003] In this known machine, a signal generator is anchored in a rotationally fixed manner at one of the ends of the machine shaft. The signal generator, which rotates with the machine shaft, together with a signal receiver arranged in a fixed manner on a housing block, forms a sensor system for detecting the rotational position of the machine shaft. The position signal is forwarded to an electronic control unit and evaluated there. For example, the position signal can be used for demand-optimized electrical control of the stator of the electric motor and / or for determining the actuation path of a piston of a pressure generator, which is driven by the machine shaft via a downstream gearbox, if necessary. The volume of brake fluid discharged into the connected brake circuit can be determined by the distance traveled by the piston, and the brake pressure to be expected in the brake circuit can be determined therefrom.

[0004] In order to connect a signal transmitter to a machine shaft in a rotationally fixed and axially fixed manner, document DE 102020 204831A1 proposes a non-positive shaft-hub connection using a clamping ring or tolerance ring. The tolerance ring is located in an annular gap between the outer circumference of the machine shaft and the inner circumference of a retaining cup of the signal transmitter, which is pushed onto the machine shaft. The latter carries a magnet as a transmitter element. Summary of the invention

[0005] The present invention further improves this known assembly in that a tolerance ring is used in addition to axially prestress the bearing rings of a rolling bearing, which is provided for supporting a machine shaft. According to the invention, for this purpose, a fastening ring or tolerance ring protrudes axially with one end from a fastening section of a retaining cup of a signal transmitter and is supported with the protruding end on the inner ring of the rolling bearing. The pressing force of the rolling bearing is generated by an elastic element, which is arranged on the opposite side of the rolling bearing and acts on the associated outer ring of the rolling bearing.

[0006] Since the support of the fastening ring or tolerance ring on the inner ring of the rolling bearing is provided, it is possible to dispense with axial support of the fastening ring or tolerance ring when installing the signal transmitter in order to prevent a movement relative to the machine shaft. The latter is particularly advantageous if the available installation space, as is common for components of motor vehicles, makes it difficult or even prevents the use of a supporting tool. The engagement of the signal transmitter can be carried out in a concealed manner, i.e. without taking measures to monitor such undesired relative movements between the tolerance ring and the machine shaft. In the assembled state, the rolling bearing is fixed in the direction of the longitudinal axis of the shaft, i.e. axially, between the fastening ring or tolerance ring and a shaft shoulder arranged on the machine shaft. Additional components, such as a retaining ring, are no longer necessary for this purpose.

[0007] Further advantages or advantageous developments of the invention are revealed in the dependent claims or in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments of the present invention are shown in the drawings and explained in detail in the following description. To this end, the drawings include several diagrams, in which:

[0009] Figure 1 A longitudinal section view showing the assembled components; and

[0010] Figure 2a-2k A method for producing the assembly is shown using successive process steps. DETAILED DESCRIPTION

[0011] according to Figure 1 As shown, the assembly (10) according to the invention comprises a machine shaft (12) which is rotatably supported in an axial bore (14) of a housing block (16). The support is provided by at least two rolling bearings, Figure 1 Only one of the rolling bearings is shown, namely the so-called second rolling bearing (20). The second rolling bearing (20) is designed, for example, as a ball bearing sealed on both sides and has an inner ring (22), an outer ring (24) and balls (26) received between the rings in a raceway section. The second rolling bearing (20) is arranged in a cylindrical part of a bearing receptacle (30) of a housing block (16), which is open conically toward the end of the machine shaft (12). An electronic control unit (28) is mounted on the housing block (16), into which the end of the machine shaft (12) extends. In the electronic control unit (28), a signal receiver (38) is arranged in a fixed position opposite the opening of the shaft hole (14).

[0012] On the side opposite the opening, the bearing receptacle (30) ends in a support shoulder (32) perpendicular to the longitudinal axis of the shaft. The support shoulder (32) serves as a first axial support for an elastic element (34), which is designed, for example, as a wave spring washer. A second axial support for the elastic element (34) forms a side wall of the outer ring (24) of the second rolling bearing (20). In the assembled state, the elastic element (34) is arranged between the two supports under the effect of axial prestressing.

[0013] The outer diameter of the machine shaft (12) is stepped at a right angle and a corresponding shoulder (18) is formed. A first shaft section with a smaller outer diameter is formed at the end of the machine shaft (12). A second shaft diameter with a larger outer diameter, in contrast, passes through an annular elastic element (34) and extends further into the shaft hole (14). A second rolling bearing (20) with the inner diameter of its inner ring (22) is accommodated on the first shaft section with a smaller diameter. The side wall of the second rolling bearing (20) with its inner ring (22) rests on the shoulder (18). There is a clearance fit between the inner diameter of the inner ring (22) of the second rolling bearing (20) and the outer diameter of the machine shaft (12), just as there is a clearance fit between the outer diameter of the outer ring (24) of the second rolling bearing (20) and the inner diameter of the bearing receptacle (30). Therefore, the second rolling bearing (20) is arranged in the bearing receptacle (30), which second rolling bearing can be moved relative to the machine shaft (12) and the housing block (16).

[0014] The machine shaft (12) protrudes from the second rolling bearing (20) with its first shaft section with a smaller diameter in the direction of the opening of the shaft hole (14). The protruding shaft section of the machine shaft (12) forms a fastening section (36) for a signal generator (40) anchored on the machine shaft (12). For this purpose, the signal generator (40) comprises a sleeve-shaped retaining cup (42) protruding beyond the end of the machine shaft and a magnet (44) carried by the retaining cup (42) as a generator element. The signal generator (40) cooperates with a signal receiver (38) in the electronic controller (28) and forms a sensor system for detecting the rotation angle of the machine shaft (12).

[0015] The retaining cup (42) of the signal generator (40) is a sleeve-shaped, open-on-both-side structural element, which is divided into a fixing section (46) at the end of the retaining cup on the rolling bearing side and a generator receptacle (48) for a magnet (44) at the end of the retaining cup on the controller side opposite the fixing section. The retaining cup (42) has a smaller inner diameter in the region of the fixing section (46) than in the region of the generator receptacle (48), so that the magnet (44) carried by the generator receptacle (48) protrudes radially beyond the end face of the machine shaft (12). The magnet (44) is directly opposite a signal receiver (38) in an electronic controller (38).

[0016] At the rolling bearing-side end, a clamping collar (50) is integrally formed on the fixing section (36) of the retaining cup (42), which protrudes outward at a right angle from the retaining cup (42). In the illustrated end position of the retaining cup (42), there is a predetermined axial distance between the clamping collar (50) and the facing side wall of the second rolling bearing (20), i.e. the retaining cup (42) and the second rolling bearing (20) do not contact each other.

[0017] The signal generator (40) is anchored to the machine shaft (12) by means of a fastening ring (52). The fastening ring (52) is located in an annular gap between the outer diameter of a first shaft section with a smaller diameter of the machine shaft (12) and the inner diameter of a fixing section (46) of a retaining cup (42). The fastening ring (52) is also known as a tolerance ring and can be a closed ring or an open ring or a slotted ring.

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

[0019] Since raceway sections for rolling elements / balls (26) are formed on both the inner ring (22) and the outer ring (24) of the second rolling bearing (20), the two bearing rings are coupled to each other in a form-fitting manner via the balls (26) and are axially movable due to the bearing play that is unavoidable for manufacturing reasons. The elastic element (34) applies a preload to the outer ring (24) of the rolling bearing (20), thereby pressing the two bearing rings of the rolling bearing (20) against each other. By pressing the machine shaft (12) in the housing block (16), a particularly quiet and wear-resistant operation of the machine equipped with the machine shaft is achieved.

[0020] When manufacturing the assembly unit, a supporting tool can be omitted, which fixes the position of the fastening ring or tolerance ring (52) on the machine shaft (12) during the assembly of the signal generator (40). The retaining cup (42) of the signal generator (40) can be pushed onto the fastening ring (52) in a concealed manner, because since the fastening ring (52) abuts axially against the inner ring (22) of the second rolling bearing (20), no relative movement between the fastening ring (52) and the machine shaft (12) in the axial direction or in the direction of the longitudinal axis of the shaft is possible.

[0021] FIG. 2 shows the manufacture of an electric motor equipped with an assembly (10) according to the invention. Figure 2a-2k The various assembly steps that follow one another are shown in a schematically simplified manner. Figure 1 2 , components corresponding to one another are uniformly provided with identical reference numerals.

[0022] Figure 2a The initial state at the beginning of the assembly process is shown. In this initial state, a housing block (16) is provided, on which an axial hole (14) is formed that passes through the housing block (16). An electric machine (in this example, an electric motor) having a stator housing (60) is fastened to one of the outer sides of the housing block (16), for example by a screw connection (not shown). A stator (62) and a rotor (64) rotatably accommodated inside the stator (62) are arranged in the stator housing (60). The rotor (64) is firmly connected to a machine shaft (12) extending into the axial hole (14). On the side opposite to the rotor, the machine shaft (12) protrudes from the housing block (16). This side of the housing block (16) is provided for fixing an electronic controller (position 28; Figure 1 ).

[0023] A first rolling bearing or ball bearing (66) is provided for rotatably supporting a machine shaft (12) or a rotor (64) firmly connected thereto in a housing block (16). The inner ring (68) of the 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 a portion of its end facing the rotor (64) on the circumference in a first bearing receptacle (72) on a housing cover (74), which covers the stator housing (60) and is also firmly pressed with a portion of its end facing away from the rotor (64) on the outside of the housing block (16) on the circumference in a second bearing receptacle (76).

[0024] A portion of the machine shaft (12) located inside the shaft bore (14) is provided with a driven element (78). This can be a spindle nut, a gear, an eccentric, a cam, etc. The driven element (78) and the machine shaft (12) can be manufactured in one piece or alternatively can be separate components that are firmly connected to each other.

[0025] The end of the shaft hole (14) of the machine housing opposite to the stator housing (60) has a supporting shoulder (32) pointing toward the opening of the shaft hole (14).

[0026] according to Figure 2b As shown, an annular elastic element (34) surrounding the machine shaft (12) has been inserted into the shaft hole (14). In the assembled state, the elastic element (34) rests on a supporting shoulder (32) formed inside the shaft hole (14).

[0027] Figure 2c A second roller or ball bearing (20) is shown which is pushed with its inner ring (22) onto the machine shaft (12) until it is aligned according to Figure 2d The second rolling bearing (20) is shown with its outer ring (24) protruding side wall resting against the elastic element (34). On the circumferential side, the second rolling bearing (20) rests against the wall of the bearing receptacle (30). Figure 2c , 2d The first clearance fit between the inner ring (22) of the second rolling bearing (20) and the machine shaft (12) or the second clearance fit between the outer ring (24) of the second rolling bearing (20) and the wall of the bearing receptacle (30) is not visible.

[0028] In accordance with Figure 2e In the step shown, a fastening ring or tolerance ring (52) is mounted on a machine shaft (12). To this end, the fastening ring (52) is first placed on the free end of the machine shaft (12) and then moved along the circumference of the shaft until the protruding end contacts the inner ring (22) of the second rolling bearing (20). To this end, a very small axial force must be applied in the direction of the longitudinal axis of the shaft, because the fit between the fastening ring (52) and the machine shaft (12) is designed as a clearance fit or transition fit.

[0029] according to Figure 2f As shown, the magnet (44) of the signal generator (40) is then inserted into the generator receptacle (48) provided for this purpose of the retaining cup (42) and secured to the retaining cup (42) by, for example, bonding or caulking. The preassembled unit consisting of the retaining cup (42) and the magnet (44) is then centered on the outer circumference of the fastening ring (52) and at least partially pressed onto the fastening ring or tolerance ring (52) using a pressing tool (80). Figure 2gFor this purpose, the pressing tool (80) engages on the rear side of the pressing collar (50) viewed in the pressing direction, which protrudes radially from the retaining cup (42).

[0030] When the retaining cup (42) begins to overlap the securing ring (52), the pressure increases and the elastic element (34) between the supporting shoulder (32) of the housing block (16) and the outer ring (24) of the second rolling bearing (20) is prestressed, because due to the pressure, the securing ring (52) moves relative to the machine shaft (12) toward the interior of the shaft bore (14) and in the process drives the abutting second rolling bearing (20) forward. The second rolling bearing (20) has reached its final position ( 18 ) by mechanical contact of the side wall of the inner ring (22) of the second rolling bearing (20) with the shaft shoulder (18) of the machine shaft (12). Figure 2h ).

[0031] according to Figure 2i As shown, the unit consisting of the retaining cup (42) and the magnet (44) is now moved further relative to the fastening ring (52) by the continuously acting pressure until a maximum overlap is reached between the retaining cup (42) and the fastening ring (52). This ends the pressing process of the signal generator (40). The fastening ring (52) is now radially prestressed by the retaining cup (42) and is firmly anchored to the machine shaft (12) due to this prestressing.

[0032] During the process of pressing the signal transmitter (40) onto the fastening ring (52), pressure acts on the inner ring (22) of the second rolling bearing (20) via the fastening ring (52). The outer ring (24) of the second rolling bearing (20) is subjected to force in the opposite axial direction by the elastic element (34) supported on the support shoulder (32) of the housing block (16). These forces acting in opposite directions on the corresponding bearing rings of the second rolling bearing (20) press the bearing rings against each other, thereby reducing the initially existing bearing clearance, i.e. the clearance of the rolling elements or balls (26) in their raceway sections on the inner ring (22) or outer ring (24) to at least almost zero. The inner ring (22) of the second rolling bearing (20) projects further into the interior of the shaft bore (14) relative to the outer ring (24).

[0033] exist Figure 2kIn the steps shown, the process of pressing the signal generator (40) onto the fastening ring (52) is completed. The pressing tool (80) is loosened and removed from the retaining cup (42). The pre-tensioned elastic element (34) loading the outer ring (24) of the second rolling bearing (20) relaxes. As a result, the outer ring (24) of the second rolling bearing (20) moves inside the associated bearing receptacle (30) in the direction of the opening of the shaft hole (14) and drives the associated inner ring (22) to move together while maintaining the existing mutual tension of the bearing rings.

[0034] The latter is clamped securely between a securing ring (52) and a shaft shoulder (18) on the machine shaft (12), so that the explained axial movement of the outer ring (24) is ultimately transmitted to the entire machine shaft (20).

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

[0036] As a result, a support is provided for the machine shaft (12), wherein the bearing rings (22, 24; 68, 70) of the two rolling bearings (20; 66) are respectively pressed against one another. This press-fit mounting of the machine shaft (12) in the housing block (16) is characterized in particular by low operating noise and high wear resistance of a machine equipped with the assembly unit (10).

[0037] Of course, modifications or additions to the explained embodiments are conceivable without departing from the basic idea of ​​the invention as claimed in the independent claims.

[0038] It should be noted in this context that the invention is not limited to application in vehicle braking devices, but can generally be implemented in any type of machine, motor or generator. While in the case of a motor it is known that electrical energy supplied to a stator (62) can be converted into a mechanical torque with which a load can be driven by a machine shaft (12) via a driven element (78), in the case of a generator the rotational motion imparted to the machine shaft (12) is used to generate electrical energy.

Claims

1. An assembly component (10), comprising: a machine shaft (12) which can be driven to perform rotational motion; 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 associated outer ring (24) received in a bearing receptacle (30) of the housing block (16); a signal generator (40) of a position detection sensor system for detecting the rotation angle of the machine shaft (12), the signal generator having a retaining cup (42) and a generator element (44) arranged at the retaining cup (42); and a fastening ring (52) which is located in an annular gap between the inner circumference of the retaining cup (42) and the outer circumference of the machine shaft (12) and is used to anchor the signal generator (40) at the end of the machine shaft (12) in a rotationally fixed and axially fixed manner, It is characterized in that The fastening ring (52) protrudes axially with one end thereof from the retaining cup (42) of the signal transmitter (40), and is axially supported with the protruding end on the side wall of the inner ring (22) of the rolling bearing (20).

2. The assembly according to claim 1, characterized in that: The bearing receptacle (30) of the housing block (16) forms a support shoulder (32) which is opposite the opening of the shaft hole (14) and on which the elastic element (34) is axially supported. The elastic element (34) applies an axial force to the outer ring (24) of the rolling bearing (20), wherein the axial force is directed in the opposite direction to the supporting force, and the fastening ring (52) is supported on the side wall of the inner ring (22) of the rolling bearing (20) by means of the supporting force.

3. The assembly according to claim 1 or 2, characterized in that: The elastic elastic element (34) is a wave elastic washer.

4. The assembly according to any one of claims 1 to 3, It is characterized in that The retaining cup (42) is a sleeve-shaped structural element open on both sides, which is divided into a fixing section (46) at one end and a generator receptacle (48) for the generator element (44) at the end opposite the fixing section. The retaining cup (42) has a smaller inner diameter in the region of the fastening section (46) than in the region of the generator receptacle (48).

5. The assembly according to claim 4, It is characterized in that The generator element (44) comprises a magnet which abuts axially within the retaining cup (42) at the transition from the generator receptacle (48) to the fastening section (46).

6. The assembly according to any one of claims 2 to 5, It is characterized in that The inner ring (22) of the second rolling bearing (20) is arranged on the machine shaft (12) by means of a clearance fit, and The outer ring (24) of the rolling bearing (20) is received in an associated bearing receptacle (30) of the housing block (16) with a clearance fit.

7. A method for producing an assembly component according to any one of claims 1 to 6, characterized in that: The method has the following steps: A housing block (16) is provided, the housing block having an axial hole (14), a bearing receiving portion (30), and a motor fixed to the housing block (16), the motor having a machine shaft (12) extending into the axial hole (14) of the housing block (16); Installing an annular elastic element (34) into a bearing receptacle (30) of the housing block (16) until the elastic element (34) abuts against a supporting shoulder (32) formed on the housing block (16); Pushing a rolling bearing (20) with an inner ring (22) onto the machine shaft (12) and inserting the second rolling bearing (20) into the bearing receptacle (30) of the housing block (16) until the side wall of the outer ring (24) of the second rolling bearing (20) abuts against the elastic element (34); Engaging a fastening ring (52) onto the machine shaft (12) until the fastening ring (52) rests axially with its forward end against the inner ring (22) of the rolling bearing (20); By applying an axial force to the signal transmitter (40), the signal transmitter (40) is pressed onto the circumference of the fastening ring (52), so that the fastening ring (52) is moved along the machine shaft (12) together with the second rolling bearing (20) and the elastic element (34) is axially prestressed until the rolling bearing (20) abuts against a shaft shoulder (18) formed on the machine shaft (12); The signal transmitter (40) is moved relative to the fastening ring (52) into an end position in which a maximum overlap of the signal transmitter (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) with the end protruding from the retaining cup (42) of the signal transmitter (40).

8. An electronically commutated motor, in particular a controllable drive device for a brake pressure generator of an electronically slip-controlled brake system of a motor vehicle, characterized in that: The electronically commutated motor has a mounting assembly (10) according to any one of claims 1 to 6.

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