drive

Abstract

Drive, wherein the drive comprises a gearbox driven by an electric motor, wherein the gearbox comprises a gearbox housing (9) in which an output shaft is rotatably mounted, and a toothed part which is rotationally fixed to the output shaft, wherein the electric motor comprises a motor housing (5), wherein the motor housing (5) is connected to the gearbox housing (9) on the driving side of the gearbox housing and thus closes an opening (130) of the gearbox housing, wherein the opening (130) has a clear diameter which exceeds the largest diameter of the toothed part, a housing part (6) of the drive comprises a yoke section, a first housing section and a second housing section, wherein the first housing section is spaced apart from the second housing section and the yoke section is connected to the first housing section and is connected to the second housing section in such a manner,that the intermediate area arranged between the first and second housing sections opens into the ambient air, wherein the first housing section at least partially surrounds a fan (20) in a housing-forming manner, wherein the first housing section has a recess designed as an inlet opening (50) extending through the wall of the housing section and opening into the intermediate area, wherein the second housing section has cooling fins (17) which extend at least partially parallel to the incoming airflow drawn in by the fan (20) and / or which are arranged on the side opposite the first housing section, wherein a receiving part (1) is connected to the yoke section on the side of the yoke section facing away from the first and second housing sections, which receives signal electronics.

Description

The invention relates to a drive.It is generally known that a drive has an electric motor which drives a transmission and can be fed by electronics, in particular inverters.From DE 195 43 284 A1, a drive unit for a model aircraft is known as the closest prior art.US 2005 / 0 167 183 A1 discloses an electric power control device for an electric motor.US 2004 / 0 150 270 A1 discloses a fully enclosed engine with external fans.A compact drive is known from DE 103 61 748 A1.DE 595 650 A discloses an electric motor assembled with a reduction gear with a motor shaft mounted on one side in the gear housing.The invention is therefore based on the object of developing a drive, wherein the highest possible drive power is to be provided in the smallest possible installation space.According to the invention, the object is achieved in the drive according to the features specified in claim 1.Important features of the invention in the drive are that the drive has a transmission driven by an electric motor, wherein the transmission has a transmission housing in which a driving shaft is rotatably mounted, and a toothed part which is connected to the driving shaft in a rotationally fixed manner, in particular wherein the toothed part is arranged in the interior space surrounded by the transmission housing, wherein the electric motor has a motor housing, wherein the motor housing is connected to the transmission housing on the driving side of the transmission housing and thus closes an opening of the transmission housing, wherein the opening has a clear diameter value which exceeds the largest diameter value of the toothed part.It is advantageous here that the driving-in opening of the transmission is the assembly opening and can also be used as a centering device for the motor. Simple assembly is thus made possible and the assembly opening is closable in a sealed manner by means of the motor. A transmission cover which closes the mounting opening of the transmission is thus not necessary. The transmission housing can thus be configured as a single piece as a cast part.Since the gear cover can be saved, a small number of parts is necessary for the production of the drive and simple production is achieved from this point.In an advantageous embodiment, the opening is the mounting opening of the transmission, i.e., in particular, the toothed part is inserted through the opening during production. It is advantageous here that a gear cover can be dispensed with.In an advantageous embodiment, the transmission housing and the motor housing are connected in a sealed, in particular oil-tight manner, in particular wherein the rotor shaft of the motor is connected in a rotationally fixed manner to a driving toothed part and is configured so as to be sealed off from the motor housing by means of a shaft sealing ring, in particular wherein the rotor shaft is mounted in the motor housing. It is advantageous here that a direct attachment of the transmission to the engine is made possible.Thus, the rotor shaft of the motor is the driving shaft of the transmission and connected in a rotationally fixed manner to that toothed part of the transmission which is assigned to the first transmission stage, in particular to the driving transmission stage. This toothed part is connected to the rotor shaft in a rotationally fixed manner. The rotor shaft itself is in turn mounted in the motor housing. The centering of the motor housing relative to the transmission housing thus centers the driving toothed part relative to the toothed part of the driving transmission stage that is in engagement therewith.In an advantageous embodiment, the motor housing has a centering collar which is centered on the edge of the opening of the transmission housing. It is advantageous here that a simple centering can be carried out, which centers the motor housing with respect to the transmission housing and thus also the driving toothed part, which is connected to the rotor shaft in a rotationally fixed manner, with respect to the toothed part of the first, i.e. driving, transmission stage that is in engagement therewith.In an advantageous embodiment, the drive has signal electronics and power electronics, wherein the electric motor has a rotor to which a fan is connected in a rotationally fixed manner, wherein the air stream drawn in by the fan at least also cools the power electronics, in particular in the suction region.It is advantageous here that all three drive components, such as transmission, motor and electronics, can be heated by an air flow. In particular, the electronics can be cooled by the air flow drawn in, and the motor can be cooled by the air flow conveyed by the fan, and the transmission can be cooled by the air flow ejected. In this way, effective cooling can be achieved.In an advantageous embodiment, the electric motor is arranged between the transmission and the power electronics, in particular the motor housing of the electric motor between the transmission housing and a housing part of the power electronics, wherein the sucked-in air flow runs at least in sections in the transverse direction to the connecting direction of the transmission and the power electronics along cooling ribs, in particular along the extension direction of cooling ribs, which are formed on the housing section of a housing part surrounding the line electronics at least partially forming a housing. It is advantageous in this case that a very compact arrangement can be achieved and the sucked-in air stream can be sucked in from the transverse direction through a slot, wherein the slot can be designed as an air inflow opening which is bounded towards the housing part of the power electronics by means of cooling ribs formed on this housing part. In this way, the sucked-in air already absorbs heat from the electronics and the conveyed air are important features in the drive according to Claim 3, that the drive has a transmission driven by an electric motor, signal electronics and power electronics, wherein the electric motor has a rotor to which a fan is connected in a rotationally fixed manner, wherein a housing part of the drive has a yoke section, a first housing section and a second housing section, wherein the first housing section is spaced apart from the second housing section and the yoke section is connected to the first housing section and is connected to the second housing section in such a way that the intermediate region arranged between the first and second housing sections opens into the ambient air, in particular wherein the housing part comprising the yoke section, the first and the second housing section is embodied in one piece, in particular in one piece, wherein the first housing section surrounds a fan at least partially forming a housing, wherein the first housing section has a recess formed as an inflow opening, in particular for an axial air flow sucked in by the fan, which recess runs through the wall of the housing section and opens into the intermediate region.It is advantageous here that the first housing section at least partially delimits the fan chamber region, i.e. also the fan, and the second housing section at least partially delimits the power electronics. Due to the spacing, thermal interaction is also avoided or at least reduced. The connecting yoke section makes it possible to attach the connection region for supply lines in the transverse direction to the connecting line of the transmission and power electronics using small installation space. This is because a receiving part with received signal electronics can be received on the yoke section. Thus, a suction of the air in the transverse direction to the connection direction of the power electronics and the transmission can be carried out and thus a very compact arrangement can be achieved, since the cooling of the geared motor together with the electronics can be carried out by means of the cooling channel.In an advantageous embodiment, the air flow drawn in by the fan cools at least the power electronics. It is advantageous here that the intake region of the air flow absorbs heat of the electronics. Thus, the air pressure is not increased here for absorbing heat, but tends to be lowered. In this way, the housing part can also be made with a smaller wall thickness or a higher leakage. In addition, a secure removal of the heat is achievable. This is because vortices which occur in quaisstationary fashion can be avoided in a simple manner and thus an effective heat removal can be achieved.In an advantageous embodiment, the second housing section has cooling ribs which extend at least in sections parallel to the incoming air flow sucked in by the fan and / or which are arranged on the side arranged opposite the first housing section. This has the advantage that an effective heat dissipation can be achieved.In an advantageous embodiment, the yoke section has one, two or more continuous recesses opening into the intermediate region. It is advantageous in this case that not only the air supply to the fan can be improved, but also a dewatering can be achieved for each mounting direction.In an advantageous embodiment, on the side of the yoke section facing away from the first and second housing sections, a receiving part is connected to the yoke section, which receiving part receives signal electronics, which are arranged in particular in a plastic housing. It is advantageous here that as close as possible to the power electronics but at a different temperature level, in particular due to the heat transfer resistance brought about by means of the receiving part and the plastic housing of the signal electronics.In an advantageous embodiment, the motor housing has at least one cooling channel, in particular which passes from the fan chamber region to the transmission, wherein the cooling channel is bounded at least in sections by a cover part. It is advantageous here that mass and weight can be saved. This is because the cover part can be produced from plastic and is also capable of delimiting an air-filled cooling region, so that no steel is necessary for this purpose.In an advantageous embodiment, the motor housing is made of metal and the cover part is made of plastic, in particular wherein the cover part is clipped to the motor housing. It is advantageous here that simple production can be carried out.In an advantageous embodiment, the cooling channel leads through a flange section of the motor housing axially into a cooling region, in particular into a cooling pocket which is bounded by the cover part, wherein the flange section is connected, in particular screw-connected, to a corresponding flange section of the first housing section. It is advantageous here that the flange section can be produced with an improved connection with respect to stability.In an advantageous embodiment, the cooling channel leads through a further flange section of the motor housing, in particular in the axial direction, wherein the air flow emerging from the cooling channel is directed onto the outer surface of the transmission, wherein the further flange section of the motor housing is connected, in particular screw-connected, to a corresponding flange section of the transmission housing, wherein the cooling channel is in particular guided axially through the corresponding flange section of the transmission housing. This has the advantage that more effective cooling can be achieved.In an advantageous embodiment, the receiving part is clipped to the yoke section, wherein the receiving part is made of metal and the yoke section is made of metal. It is advantageous here that two metallic parts can be connected in a simple manner and thus simple production is made possible. In addition, the heat can be spread out and the heat dissipation by means of the receiving part can thus be improved.In an advantageous embodiment, a heat spreading plate is arranged on the inner side of the second housing section, on which a power semiconductor is arranged. It is advantageous here that the peak temperature can be lowered by the heat being expandable by means of the heat expansion plate.In an advantageous embodiment, the yoke section and the receiving part are formed in one piece. It is advantageous in this case that the number of parts can be reduced and thus the production can be simplified.In an advantageous embodiment, a reinforcing rib and a cable guide are formed on the receiving part and / or a recess for the passage of electrical lines to the stator winding of the stator of the electric motor. It is advantageous here that an increased stability can be achieved in a simple manner with little outlay and a shaped cable guide can be provided in the cast part and thus without additional outlay, wherein material can be saved. In addition, the lines to the stator can also be passed through the material-saving recess.Further advantages are evident from the dependent claims. The invention is not limited to the combination of features of the claims. The skilled person will be familiar with further meaningful combination possibilities of claims and / or individual claim features and / or features of the description and / or of the figures, in particular from the task and / or the task which arises by comparison with the prior art.The invention will now be explained in more detail with reference to the drawings:FIG. 1 shows a cross section through a drive according to the invention, which has a gear driven by an electric motor, wherein the electric motor is fed by an inverter, wherein the inverter has power electronics and signal electronics, wherein the signal electronics are accommodated in a receiving part 1 of the drive, which is preferably embodied as metallic.FIG. 2 shows an oblique view of the drive, wherein the cooling region 18 is not covered.FIG. 3 shows a plan view of the receiving part 1 with the signal electronics removed.FIG. 4 shows an oblique view of the receiving part 1 with the signal electronics removed.FIG. 5 shows an air duct 8 which leads from the fan space region 19 into the cooling region 18 on the outside of the motor housing 5.FIG. 6 shows a plan view from the fan side onto the motor housing 5.FIG. 7 again shows the air duct 8 which leads from the fan space region 19 into the cooling region 18 on the outer side of the motor housing 5, the stator laminated core 12 and the stator windings 11 being shown.FIG. 8 shows a plan view of the part of the housing part 6 surrounding the power electronics in a housing-forming manner, wherein the invisible air inlet opening 7 lies in front of the cooling ribs 17, that is to say in front of the cooling ribs 17 in the viewing direction, and the part of the housing part 6 surrounding the fan space region 19 in a housing-forming manner is cut out.FIG. 9 shows a cover part 90, which is preferably made of plastic and on the inside of which turbulators 91 are formed, which covers the cooling region 18 and thus provides a cooling duct between the motor housing 5 and the cover part 90, wherein the turbulators 91 bring about an increase in the turbulence and thus an overall lower heat transfer resistance between the stator and ambient air.In FIG. 10, an alternatively conceivable cover part 90 is shown, which is embodied without turbulators.The drive is shown in an oblique view in FIG. 11, wherein air outlet openings formed in the motor housing, which are designated by reference numeral 120 in FIG. 12, are also shown, from which an air stream directed toward the transmission housing 9 respectively exits and thus brings about cooling.In FIG. 12, the drive is shown in an oblique view, with the cover parts 90 being hidden.In FIG. 13, only the transmission housing 9 is shown in an oblique view, shafts and toothed parts of the transmission and its lubricating oil not being shown.As shown in the figures, the drive has a transmission with transmission housing 9, in which bearings are accommodated, which support shafts that are connected to toothed parts in a rotationally fixed manner. The driving-in stage of the transmission is driven by a toothed part, in particular a pinion, which is connected in a rotationally fixed manner to the rotor 10 of an electric motor. The rotor 10 is mounted in the motor housing 5 via a bearing 13 and in the housing part 6 via a bearing 3, wherein the transmission housing 9 is connected to the motor housing 5 and the motor housing 5 is connected to the housing part 6.The motor housing 5 accommodates the stator laminated core 12 into which the stator winding 11 is drawn. At the end region of the rotor 10 facing away from the gear, a fan 20 is connected to the rotor 10 in a rotationally fixed manner. This fan 20 draws an air flow from an air inlet opening 7 through a round opening 50.In this case, the fan 20 covers a greater radial distance range in the radial direction starting from the rotor axis than the round opening 50. the round opening 50 is formed as a recess in the wall of the housing part 6 and extends at least ten times more in the radial direction than in the axial direction at all circumferential angles. Thus, the sucked-in air flow enters the fan space region 19 substantially axially from the air inlet opening 7.The air inlet opening 7 is shaped such that the air flow enters substantially in one or more circumferential angle regions spaced apart from one another from the radial direction.The air inlet opening 7 is slot-like, so that the air flow enters from below in FIG. 1 and flows along the cooling ribs 17, which are arranged on that region of the housing part 6 which surrounds the power electronics.The spatial area covered by the power electronics overlaps with the spatial area covered by the fan 20.The housing part 6 has a first housing section which surrounds the fan space region 19 in a housing-forming manner.The housing part 6 has a second housing section which surrounds the power electronics in a housing-forming manner.The first and second housing portions are connected by means of a yoke portion on which a receiving portion is placed.The yoke section, the first housing section and the second housing section are embodied in one piece, i.e. in one piece. The housing part 6 is preferably made of metal, such as aluminum or steel.The first and second housing portions are axially spaced apart from each other so as to form the air inlet opening 7. Cooling ribs 17 are formed on the side of the second housing section facing the first housing section and / or on the side of the second housing section facing the air inlet opening 7, so that the air flowing in from the outside through the air inlet opening 7 must flow along the cooling ribs 17 and thus cools the power electronics.On the inner side of the second housing section, a heat spreading plate 15 is arranged, which is connected to the second housing section in a heat-conducting manner, on the side of the heat spreading plate 15 facing away from the connection region between the heat spreading plate 15 and the second housing section, at least one power semiconductor 14 is connected in a heat-conducting manner. The heat of the power electronics is thus dissipated to the cooling ribs 17.The yoke section has two recesses 2 which open into the air inlet opening 7, so that, on the one hand, air also flows in from the side opposite the air inlet opening 7 and thus drainage also takes place in each design, since the air inlet opening 7 opens into the environment opposite the recesses 2.The motor housing 5 is screw-connected to the housing part 6 by means of screws 4.A substantially axially extending air duct 8 connects the fan space region 19 to the cooling region 18, so that the air flow conveyed by the fan 20 flows through the air duct into the fan space region 19, flows along the motor housing 5 there through an air outlet opening 120 and impinges on the outer surface of the gearbox housing 9, so that the air flow absorbs heat generated by the power electronics from the cooling ribs 17, absorbs heat generated by the stator and finally also absorbs heat generated by the gearbox and then escapes into the environment.Preferably, the air outlet openings 120 are shaped like nozzles, i.e. are designed with a narrowed cross section in the flow direction, so that a more rapidly emerging air flow can be generated.On the side of the yoke section facing away from the first and second housing sections, the receiving part 1 is connected to the yoke section. The receiving part 1 is also metallic. On the side of the receiving part 1 facing away from the yoke section and the first and the second housing section, a housing part 16, which is preferably designed as a plastic housing part, and surrounds signal electronics at least partially forming a housing.Thus, an operating part can be placed on the receiving part 1, with which the power electronics can be controlled.A cable guide 30 for supply lines is formed in the receiving part 1 and a cable channel 31 which enables lines to be passed through to the stator winding. Reinforcing ribs 32 are also formed on the receiving part 1.The cover parts 90 are preferably made of plastic as plastic injection molded parts. As shown in FIG. 9, the turbulators 91 formed on the inner side of the cover members 90 protrude into the cooling portion 18, thus improving heat dissipation from the stator to the outside.Alternatively, however, cover parts 100 without such turbulators can also be used.Both kinds of cover parts (90, 100) are clipped to the motor housing 5.Thus, cooling areas 18 which can be flowed through by the air flow and are surrounded at least partially forming the housing by the respective cover part (90, 100) are provided as channels.As shown in the figures, such cooling regions are regularly spaced apart from one another in the circumferential direction.The transmission, motor and power electronics are substantially coaxial, that is to say arranged in a line, wherein the motor is arranged axially between the transmission and the power electronics. The air intake takes place in the transverse direction to this axial direction, namely via the air inlet opening 7 and the recesses 2.As shown in FIG. 6, eight air passages 8 are arranged in the circumferential direction. In each of the corner regions, which are arranged between the corners of the cuboidal motor housing 5 and the largest radial spacing of the stator laminated core 12, two air ducts 8 spaced apart from one another in the circumferential direction are formed.The gear housing 9 has a flange region projecting stepwise outwards, in which the screw connection to the motor housing 5 is carried out.The air outlet openings 120 pass through these step regions in the axial direction.The metallic receiving part 1 is connected by means of a clip connection 80 to the housing part 6, which is likewise metallic.The recesses 2 open on both sides of the housing part 16 of the signal electronics. They are therefore spaced apart from one another in the transverse direction by means of the signal electronics. The signal electronics are designed as an operating part, i.e. with input means and output means.For connecting the housing part 6 to the motor housing 5, both have a flange section, through which screw parts can be passed. The motor housing 5 and the transmission housing 9 likewise have flange sections of corresponding design. Moreover, said flange portions are formed with axially through recesses which are parts of the cooling channel from the fan space portion 19 through the cooling portions.As shown in FIG. 13, the transmission case 9 has an opening 130 on the driving side and an opening 131 on the driven side.The motor housing 5 covers the opening 130 when connected to the gear housing 9. This is because the motor housing 5 is connected to the transmission housing 9 on the driving-in side thereof. On the driven side, the driven shaft of the transmission protrudes to the outside through the opening 131.For mounting the transmission, at least the driving-off toothed part of the transmission, i.e. the toothed part with the largest diameter, is introduced through the opening 130 into the interior of the transmission housing 9. The other gear parts and the shafts of the transmission are inserted either through the opening 130 or through the opening 131 into the interior of the transmission.Therefore, the largest diameter of the aperture 130 exceeds the largest outer diameter of the largest spline portion of the transmission. In the finished transmission, this largest toothed part is connected in a rotationally fixed manner to the driving-off shaft.The connection between the transmission housing 9 and the motor housing 5 is oil-tight.Furthermore, the motor housing 5 is centered on the edge of the opening 130 by means of a centering collar.List of reference characters1 Receiving part 2 Recess, in particular suction opening and drainage opening 3 Bearing in the housing part 6 4 Screw 5 Motor housing 6 Housing part for fan and power electronics 7 Air inlet opening, in particular slot-like air inlet opening 8 Air duct 9 Transmission housing 10 Rotor 11 Stator winding 12 Stator laminated core 13 Bearing in the motor housing 5 14 Power semiconductor 15 Heat spreading plate 16 Housing part, in particular plastic housing part for signal electronics 17 Cooling ribs 18 Cooling region 19 Fan space region 20 Fan 30 Cable guide 31 Cable duct 32 Reinforcing rib 50 Opening, in particular bore, on inclined surface as inflow opening for fan air flow 80 Clip connection 90 Cover part 91 Turbulators 100 Cover part 120 Air outlet opening 130 Opening on the driving-in side 131 Opening on the driving-out side

Claims

Drive, wherein the drive has a transmission driven by an electric motor, wherein the transmission has a transmission housing (9) in which a driving shaft is rotatably mounted, and a toothed part which is connected to the driving shaft in a rotationally fixed manner, wherein the electric motor has a motor housing (5), wherein the motor housing (5) is connected to the transmission housing (9) on the driving side of the transmission housing and thus closes an opening (130) of the transmission housing, wherein the opening (130) has a clear diameter value which exceeds the largest diameter value of the toothed part, a housing part (6) of the drive has a yoke section, a first housing section and a second housing section, wherein the first housing section is spaced apart from the second housing section and the yoke section is connected to the first housing section and is connected to the second housing section in such a way that the intermediate region arranged between the first and second housing sections opens into the ambient air, wherein the first housing section surrounds a fan (20) at least partially forming the housing, wherein the first housing section has a recess formed as an inflow opening (50), which runs through the wall of the housing section and opens into the intermediate region, wherein the second housing section has cooling ribs (17), which extend at least in sections parallel to the inflowing air stream sucked in by the fan (20) and / or which are arranged on the side arranged opposite the first housing section, wherein a receiving part (1) is connected to the yoke section on the side of the yoke section facing away from the first and second housing sections, wherein a receiving part (1) is connected to the yoke section, which accommodates signal electronics.Drive according to Claim 1, characterized in that the opening (130) is the installation opening of the gearbox, that is to say the toothed part is inserted through the opening (130) during production.Drive according to at least one of the preceding claims, characterized in that the transmission housing (9) and the motor housing (5) are tightly connected.Drive according to at least one of the preceding claims, characterized in that the motor housing (5) has a centring collar which is centred on the edge of the opening (130) of the gearbox housing.Drive according to at least one of the preceding claims, characterized in that the drive has the signal electronics and power electronics, wherein a fan (20) is connected to the rotor shaft in a rotationally fixed manner, wherein the air stream drawn in by the fan (20) at least also cools the power electronics.Drive according to Claim 5, characterized in that the electric motor is arranged between the gearbox and the power electronics, wherein the air flow drawn in runs at least in sections in the transverse direction to the connecting direction of the gearbox and the power electronics along cooling ribs (17).Drive according to at least one of the preceding claims, characterized in that the housing part (6), comprising the yoke section, the first and the second housing section, is embodied in one piece and in one piece.Drive according to Claim 5 or 6, characterized in that the air stream sucked in by the fan (20) cools at least the power electronics.Drive according to at least one of the preceding claims, characterized in that the yoke section has one, two or more continuous recesses (2) opening into the intermediate region.Drive according to at least one of the preceding claims, characterized in that the motor housing (5) has at least one cooling duct, wherein the cooling duct is bounded at least in sections by a cover part (90).Drive according to Claim 10, characterized in that the motor housing (5) is produced from metal and the cover part (90) is produced from plastic, the cover part (90) being clipped to the motor housing (5).Drive according to the preceding claim, characterized in that the cooling duct passes from the fan chamber region (19) to the gearboxDrive according to Claim 10 or 11, characterized in that the cooling duct leads axially through a flange section of the motor housing (5) into a cooling region (18), that is to say into a cooling pocket which is bounded by the cover part (90), wherein the flange section is connected to a corresponding flange section of the first housing section.Drive according to one of Claims 10 to 13, characterized in that the cooling duct leads through a further flange section of the motor housing (5), wherein the air stream emerging from the cooling duct is directed onto the outer surface of the transmission, wherein the further flange section of the motor housing (5) is connected to a corresponding flange section of the transmission housing (9), wherein the cooling duct is in particular guided axially through the corresponding flange section of the transmission housing (9).Drive according to at least one of the preceding claims, characterized in that the receiving part (1) is clipped to the yoke section, wherein the receiving part (1) is made of metal and the yoke section is made of metal.Drive according to at least one of the preceding claims, characterized in that a heat spreading plate (15) is arranged on the inner side of the second housing section, on which a power semiconductor (14) is arranged.Drive according to one of Claims 1 to 14, characterized in that the yoke section and the receiving part (1) are formed in one piece.Drive according to at least one of the preceding claims, characterized in that a reinforcing rib (32) and a cable guide (30) are formed on the receiving part (1).

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