DE102018217655B3 - Housing of an electrical machine with an integrated belt tensioning system - Google Patents

Abstract

The invention relates to a housing (18) of an electrical machine (10) with an integrated belt tensioning system (22), comprising a first lever arm (24) on the housing (18) and a first pivot point (26) of the first lever arm ( 24) at least partially pivotably mounted first tensioning roller (28), a second tensioning roller (30) arranged at a distance from the first tensioning roller (28) on the housing (18), the second tensioning roller (30) via a different from the first lever arm (24) second lever arm (38) is arranged on the housing (18) and is mounted on the housing (18) so as to be pivotable about a second pivot point (40) of the second lever arm (38) at least partially against the spring force of the spring element (34), and a spring element ( 34) that is arranged and / or designed such that at least the first tensioning roller (28) can be displaced against a spring force of the spring element (34), the first tensioning roller (28) and the second tensioning roller (30) are arranged and / or configured to one another in such a way that a belt (36) can be guided between the first tensioning roller (28) and the second tensioning roller (30) and can be looped around a pulley (16) of the electrical machine (10), and at least via the First tensioning roller (28) a tensioning force can be applied to the belt (36), the spring element being arranged on a side facing the housing (18) and / or on a side facing away from the housing (18) of the respective lever element (24, 38) / or is attached.

Description

The invention relates to a housing of an electrical machine with an integrated belt tensioning system, the belt tensioning system being arranged directly on the housing of the electric machine.

Belt tensioning systems for tensioning a belt of an electrical machine, such as the belt of a belt starter generator RSG, are generally known. A belt starter generator is usually also referred to as a "Belt Starter Generator" BSG. Known belt tensioning systems of a belt starter generator of this type generally have a base plate which is screwed onto the housing of the electrical machine. The base plate generally has a central opening through which the rotor shaft or the pulley fitted to the rotor shaft is guided. An at least semicircular annular spring is arranged in the circumferential direction around the pulley. The ring spring is operatively connected to a tensioning roller arranged at the respective end of the semicircular ring spring for tensioning a belt guided around the pulley. In the known belt tensioning system it is accordingly provided that the belt tensioning system is designed as a complete unit. This has the advantage that the belt tensioning system can be manufactured separately from the housing and can be screwed onto the housing as a whole system. A disadvantage of the known belt tensioning system, however, is that the belt tensioning system can have an increased weight and increased manufacturing costs due to the large number of parts.

A belt tensioner described above is for example from the DE 10 2014 203 952 A1 known.

The DE 10 2005 039 719 A1 describes an object according to the preamble of claim 1.

The DE 10 2015 211 157 A1 describes a method for determining the torque in a belt drive.

From the DE 100 44 645 A1 a device for regulating the tensioning means pre-tension according to need is known.

The WO 2015 167 602 A1 describes a belt tensioner

It is the object of the present invention to provide a housing of an electrical machine with an integrated belt tensioning system, which can be manufactured inexpensively and has a reduced installation space in the axial direction.

This object is achieved by the subject matter of patent claim 1. Preferred developments of the invention are specified in the following description, the subclaims and the drawings, each feature being able to represent an aspect of the invention both individually and in combination.

According to the invention, a housing of an electrical machine with an integrated belt tensioning system is provided, comprising a first tensioning roller arranged on the housing via a first lever arm and at least partially pivotable about a first pivot point of the first lever arm, a second tensioning roller arranged on the housing spaced apart from the first tensioning roller, and a spring element which is arranged and / or configured such that at least the first tensioning roller can be displaced against a spring force of the spring element, the first tensioning roller and the second tensioning roller being arranged and / or configured relative to one another such that between the first tensioning roller and the second belt a belt can be guided and looped around a pulley of the electrical machine, and at least a tension force can be applied to the belt via the first belt tensioner.

In other words, it is an aspect of the present invention that an electrical machine housing with an integrated belt tensioning system is provided. The electrical machine is preferably an electrical drive device, in particular a generator, of an at least partially electrically driven motor vehicle. The housing encloses and / or at least partially surrounds the electrical machine. The housing also includes an integrated belt tensioning system.

The belt tensioning system has a first tensioning roller, which is arranged on the housing via a first lever arm and is at least partially pivotable about a first pivot point of the lever arm. This means that the first tensioning roller is connected directly to the housing via the first lever arm in such a way that the first lever arm can be pivoted about the first pivot point. The first pivot point can preferably be designed as a screw, bolt and / or rivet connection in order to arrange the first lever arm on the housing so that it is designed to be pivotable about the first pivot point. The first tensioning roller is mounted in the first lever arm such that it can be rotated about an axis of rotation of the first tensioning roller.

Furthermore, the belt tensioning system comprises a second tensioning roller arranged at a distance from the first tensioning roller on the housing. The second tension roller is rotatable and its axis of rotation is formed. In addition, a spring element is provided, which is arranged and / or designed such that at least the first tensioning roller can be displaced against a spring force of the spring element. The first tensioning roller and the second tensioning roller are arranged and / or configured with respect to one another such that a belt can be guided between the first tensioning roller and the second tensioning roller and can be looped around a pulley of the electrical machine. At least one tensioning force can be applied to the belt via the first tensioning roller so that it can be tensioned.

It is accordingly provided that the first tensioning roller is arranged directly on the housing of the electrical machine via the first lever arm. The second tensioning roller can be arranged directly or indirectly on the housing of the electrical machine. The second tensioning roller is arranged directly on the housing if the second tensioning roller is arranged directly on the housing, the second tensioning roller being mounted on the housing so as to be rotatable about an axis of rotation. There is an indirect arrangement of the second tensioning roller on the housing when the second tensioning roller is arranged on the housing via a corresponding lever arm.

For the integrated belt tensioning system, at least no separate carrier plate is required for fastening the belt tensioning system on the housing of the electrical machine. The number of parts of the belt tensioning system can thus be reduced. In addition, the weight and costs can be reduced.

For example, the second tensioning roller can be designed as a deflection roller. Accordingly, the second tensioning roller is arranged directly on the housing. The second tensioning roller then only serves to guide or deflect the belt guided around the pulley.

According to the invention, the second tensioning roller is arranged on the housing via a second lever arm that differs from the first lever arm and is mounted on the housing so as to be pivotable at least partially against the spring force of the spring element about a second pivot point. This means that the second tensioning roller is attached indirectly to the housing of the electrical machine via the second lever arm. The second pivot point can preferably be designed as a screw, bolt and / or rivet connection in order to arrange the second lever arm on the housing so that it is designed to be pivotable about the second pivot point.

In principle, it can be provided that the length of the first lever arm is equal to the length of the second lever arm. In this way, the clamping force applied via the spring force via the first lever arm can be equal to the clamping force of the second lever arm.

Alternatively, a preferred development of the invention is that the length of the first lever arm is different from the length of the second lever arm. In this way, the tensioning force applied to the belt can be varied over the length of the respective lever arm.

Basically it is provided that the spring element is designed and / or arranged such that at least the first tensioning roller is designed to be displaceable against the spring force of the spring element.

A preferred development of the invention is that the spring element is arranged and / or tensioned between the first lever element and the second lever element. In this way, the first lever element and the second lever element are connected to one another via the spring element. Both the first tensioning roller and the second tensioning roller can thus be displaced against the spring element. Accordingly, a tensioning force can be exerted on the belt both via the first tensioning roller and via the second tensioning roller.

According to the invention, the spring element is arranged and / or fastened on a side facing the housing and / or on a side of the respective lever element facing away from the housing. It can thus preferably be provided that the spring element is arranged on a side of the first lever element and the second lever element facing the housing. This has the advantage that in a first step both the first lever element and the second lever element are arranged on the housing of the electrical machine. In a second step, the spring element is tensioned between the first lever element and the second lever element on the side of the respective lever element facing the housing. The belt can then be guided between the first tensioning pulley and the second tensioning pulley and placed around the pulley.

In order to reduce and / or avoid spring force-related tilting moments of the first lever arm and / or the second lever arm, it is provided that, in addition to the side of the lever elements facing the housing, also on the side of the housing opposite side of the lever elements, the spring element is arranged.

The invention also relates to an electrical machine for a motor vehicle, comprising a rotor shaft rotatably mounted about a rotor shaft axis with a pulley mounted on a shaft end of the rotor shaft, a housing according to the invention surrounding the electrical machine at least in sections, with a rotor shaft opening through which the rotor shaft is guided, and a belt that runs at least between the first tensioning roller and the second tensioning roller and that wraps around the pulley at least in sections.

A preferred development of the invention is that in the tensioned state of the belt, the smallest distance a between an outer circumference of the first tensioning roller and an outer circumference of the second tensioning roller is equal to or less than the outer diameter d of the pulley. In the tensioned state of the belt, the spring element therefore exerts a tensioning force on the belt at least via the first tensioning roller. In this state, the smallest distance a between the outer circumference of the first tensioning roller and the outer circumference of the second tensioning roller is less than or equal to the outer diameter d of the pulley. The belt is thus arranged in a substantially horseshoe shape around the pulley and is guided between the first tensioning roller and the second tensioning roller.

In an advantageous development of the invention it is provided that the rotor shaft axis, the first pivot point and the second pivot point are arranged and / or configured with respect to one another in such a way that they form an isosceles triangle. It is provided that the distance between the rotor shaft axis and the first pivot point is equal to the distance between the rotor shaft axis and the second pivot point. In this context, if the length of the first lever arm is equal to the length of the second lever arm, the same pretensioning force can preferably be applied to the belt via the first tensioning roller and the second tensioning roller.

A preferred development of the invention provides that the electrical machine has at least one deflection sensor for detecting a deflection of the first lever arm and / or the second lever arm. The deflection of the first lever arm and / or the second lever arm can provide information and / or information about the tension of the belt guided around the pulley. This information is preferably forwarded to a control of the electrical machine in order to take precautions and / or measures to reduce the power loss of the electrical machine.

The invention also relates to a motor vehicle with at least a partially electric drive, comprising the electric machine according to the invention.

Further features and advantages of the present invention result from the subclaims and from the following exemplary embodiments. The exemplary embodiments are not restrictive, but rather are to be understood as exemplary. They are intended to enable the person skilled in the art to carry out the invention. The applicant reserves the right to make one or more of the features disclosed in the exemplary embodiments the subject of patent claims or to include such features in the existing claims. The exemplary embodiments are explained in more detail with reference to drawings.

• 1 eine Aufsicht auf das Gehäuse der elektrischen Maschine mit einer über einen ersten Hebelarm auf dem Gehäuse angeordneten ersten Spannrolle und einer auf dem Gehäuse angeordneten zweiten Spannrolle, gemäß einem ersten bevorzugten Ausführungsbeispiel der Erfindung,
• 2 eine Aufsicht auf das Gehäuse der elektrischen Maschine, wobei die erste Spannrolle und die zweite Spannrolle jeweils über einen Hebelarm auf dem Gehäuse der elektrischen Maschine verschwenkbar gelagert sind, gemäß einem zweiten Ausführungsbeispiel der Erfindung,
• 3 die Aufsicht auf das Gehäuse der elektrischen Maschine, wobei der jeweilige Hebelarm der ersten Spannrolle und der zweiten Spannrolle unterschiedliche Längen aufweist, gemäß einem dritten Ausführungsbeispiel der Erfindung,
• 4 eine Detailansicht der Anordnung des Federelements zwischen dem ersten Hebelelement und dem zweiten Hebelelement.

In these show:

• 1 2 shows a plan view of the housing of the electrical machine with a first tensioning roller arranged on the housing via a first lever arm and a second tensioning roller arranged on the housing, according to a first preferred exemplary embodiment of the invention,
• 2nd 2 shows a top view of the housing of the electrical machine, the first tensioning roller and the second tensioning roller each being pivotably mounted on the housing of the electrical machine via a lever arm, according to a second exemplary embodiment of the invention,
• 3rd the supervision of the housing of the electrical machine, the respective lever arm of the first tensioning roller and the second tensioning roller having different lengths, according to a third embodiment of the invention,
• 4th a detailed view of the arrangement of the spring element between the first lever element and the second lever element.

In 1 is an electrical machine 10th shown for an at least partially electrically operated motor vehicle, the electrical machine being set up to drive the at least partially electrically operated motor vehicle. The electrical machine 10th has at least one around a rotor shaft axis 12th rotatably mounted rotor shaft 14 on, on one shaft end of the rotor shaft 14 a pulley 16 is arranged.

The electrical machine 10th is at least partially from a housing 18th surrounded, the housing 18th one coaxial to Rotor shaft axis 12th arranged rotor shaft opening 20th through which the rotor shaft 14 is led. The pulley 16 is therefore outside the case 18th arranged. The housing 18th also features an integrated belt tensioning system 22 on.

The belt tensioning system 22 includes one over a first lever arm 24th on the case 18th around a first pivot 26 at least partially pivotably mounted first tensioning roller 28 . The belt tensioning system also includes 22 one to the first idler 28 different second tension pulley 30th that are directly on the housing 18th is arranged. The first idler 28 and the second idler 30th are each parallel to the axis of the rotor shaft 12th extending axis of rotation 32 rotatably mounted. The distance between the rotor shaft axis 12th and the axis of rotation 32 the first tension pulley 28 is equal to the distance of the rotor shaft axis 12th and the axis of rotation 32 the second tension pulley 30th . Between the first tension pulley 28 and the second tension pulley 30th is a spring element 34 arranged and / or designed such that at least the first tensioning roller 28 against a spring force of the spring element 34 is relocatable. The first lever arm swings 24th around the first pivot 26 . The first pivot 26 can preferably be designed as a screw connection around the first lever arm 24th on the case 18th to be pivoted. This can be done in the housing 18th a corresponding fastening device for receiving the screw connection may be formed.

The first idler 28 and the second idler 30th are arranged to each other in such a way that between the first tensioning roller 28 and the second tension pulley 30th a strap 36 feasible and around the pulley 16 is loopable, the first tensioning roller 28 a tension on the belt 36 exercises. It is therefore provided that the belt tensioning system 22 directly on the housing 18th of the electrical machine 10th is arranged. The belt tensioning system 22 thus has no separate housing and also no separate carrier plate around the belt tensioning system on the housing 18th of the electrical machine 10th to fix. Because there is no separate housing or separate support plate for the belt tensioning system 22 the weight of the belt tensioning system 22 be reduced. It can also reduce the cost of the electrical machine 10th be reduced.

The 2nd shows a second embodiment of the electrical machine 10th . Unlike the one from 1 known electrical machine 10th points the electrical machine 10th according to the second embodiment, an integrated belt tensioning system 22 on, with the second idler pulley 30th over one of the first lever arm 24th different second lever arm 38 on the case 18th arranged and over a second pivot point 40 of the second lever arm 38 at least partially against the spring force of the spring element 34 pivotable on the housing 18th is stored. Accordingly, it is provided that the first tensioning roller 28 over the first lever element 24th around the first pivot 26 is rotatably mounted, and the second tensioning roller 30th via the second lever arm 38 around the second pivot 40 . The holder for attaching the first lever arm 24th around the first pivot 26 is directly in the housing 18th educated. This also applies to the formation of the connection of the second lever arm 38 around the second pivot 40 . The spring element 34 is between the first tension pulley 28 and the second tension pulley 30th arranged. It can preferably be provided that the spring element 34 on the first lever arm 24th and the second lever arm 38 attached and / or anchored.

In the second embodiment of the invention, the length of the first lever arm 24th equal to the length of the second lever arm 38 . In addition, the distance between the rotor shaft axis 12th and the first pivot 26 equal to the distance of the rotor shaft axis 12th to the second pivot point 40 . The rotor shaft axis, the first pivot point 26 and the second pivot 40 are thus arranged to each other in such a way that they form an isosceles triangle. Thus, the first tension pulley 28 and the second idler 30th an even tension on the belt 36 be applied. It can also be seen that in the tensioned state of the belt 36 the smallest distance a between the outer circumference of the first tension pulley 28 and an outer periphery of the second idler 30th smaller the outer diameter d of the pulley 16 is.

3rd shows the electrical machine 10th according to a third embodiment of the invention. Unlike the one in 2nd electrical machine shown 10th indicates the in 3rd electrical machine shown 10th a first lever arm 24th on whose length is different from the length of the second lever arm 38 is. The first lever arm is specific 24th opposite the second lever arm 38 shortened. The distance between the rotor shaft axis 12th and the axis of rotation 32 the first tension pulley 28 is equal to the distance of the rotor shaft axis 12th and the axis of rotation 32 the second tension pulley 30th . Over the lengths of the respective lever arms 24th , 38 and the arrangement of the pivot points 26 , 40 of the respective lever arms 24th , 38 , can from the first tension pulley 28 and / or second tension pulley 30th applied spring force can be adjusted and / or varied.

In 4th is a detailed view of the arrangement of the spring element 34 on the first lever arm 24th and on the second lever arm 38 shown. Accordingly, the spring element 34 a first lever arm 24th and on the second lever arm 38 attached. In the present embodiment, the spring element 34 on one of the housing 18th facing side and on one of the housing 18th opposite side of the respective lever element 24th , 38 arranged. In this way, tension-related tilting forces can be exerted on the first lever arm 24th and / or the second lever arm 38 work, be reduced. In principle, however, it is also conceivable that preferably only one spring element 34 it is provided that on the the housing 18th facing side of the first lever element 24th and the second lever element 38 , or on the case 18th opposite side of the respective lever arm 24th , 38 is arranged. Due to the fact that the spring element 34 directly, i.e. the shortest way between the first lever element 24th and the second lever element 38 is arranged, there is no need to deflect the spring force in the circumferential direction around the pulley 16 .

Reference list

10th

Electrical machine

12th

Rotor shaft axis

14

Rotor shaft

16

Pulley

18th

casing

20th

Rotor shaft opening

22

Belt tensioning system

24th

First lever arm

26

First pivot point

28

First tension pulley

30th

Second tension pulley

32

Axis of rotation

34

Spring element

36

belt

38

Second lever arm

40

Second pivot point

Claims (9)

Housing (18) of an electrical machine (10) with an integrated belt tensioning system (22), comprising - at least a first lever arm (24) arranged on the housing (18) and around a first pivot point (26) of the first lever arm (24) partially pivotably mounted first tensioning roller (28), - a second tensioning roller (30) arranged at a distance from the first tensioning roller (28) on the housing (18), the second tensioning roller (30) via a second lever arm which is different from the first lever arm (24) (38) is arranged on the housing (18) and is mounted on the housing (18) so as to be pivotable about a second pivot point (40) of the second lever arm (38) at least partially against the spring force of the spring element (34), and - a spring element (34 ) that is arranged and / or designed such that at least the first tensioning roller (28) can be displaced against a spring force of the spring element (34), wherein - the first tensioning roller (28) and the second tensioning roller (30) are arranged in relation to one another in this way are arranged and / or designed such that a belt (36) can be guided between the first tensioning roller (28) and the second tensioning roller (30) and can be looped around a pulley (16) of the electrical machine (10), and at least via the first tensioning roller (28) a tension force can be applied to the belt (36), characterized in that the spring element is arranged on a side of the respective lever element (24, 38) facing the housing (18) and / or on a side facing away from the housing (18) and / or is attached. Housing after Claim 1 , characterized in that the length of the first lever arm (24) is equal to the length of the second lever arm (38). Housing after Claim 1 , characterized in that the length of the first lever arm (24) is different from the length of the second lever arm (38). Housing according to one of the Claims 1 to 3rd , characterized in that the spring element (34) is arranged and / or tensioned between the first lever element (24) and the second lever element (38). Electrical machine (10) for a motor vehicle, comprising - a rotor shaft (14) rotatably mounted about a rotor shaft axis (12) with a pulley (16) arranged on a shaft end of the rotor shaft (14), - an electrical machine (10) at least in sections surrounding housing (18) according to one of the Claims 1 to 4th , with a rotor shaft opening (20) through which the rotor shaft (14) is guided, and a belt (36) which runs at least between the first tensioning roller (28) and the second tensioning roller (30) and the pulley (16) at least in sections wraps around. Electrical machine after Claim 5 , characterized in that in the tensioned state of the belt (36), the smallest distance (a) between an outer circumference of the first tensioning roller (28) and an outer circumference of the second tensioning roller (30) is equal to or less than the outer diameter (d) of the pulley. Electrical machine according to one of the Claims 5 or 6 , characterized in that the rotor shaft axis (12), the first pivot point (26) and the second pivot point (40) are arranged and / or configured with respect to one another in such a way that they form an isosceles triangle. Electrical machine according to one of the Claims 5 to 7 , comprising at least one deflection sensor for detecting a deflection of the first lever arm (24) and / or the second lever arm (38). Motor vehicle with at least one partially electric drive, comprising an electric machine (10) according to one of the Claims 5 to 8th .

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