DE102020212704B4 - Actuator with intermediate plate, which holds a rotary bearing - Google Patents

Abstract

An actuator (10; 10') having a housing (20), a cantilever (30) and a lead screw (41), said housing (20) comprising a first end block (21) and a housing main body (80), said lead screw ( 41) in the region of the first end block (21) by means of a rotary bearing (24) so as to be rotatable with respect to an axis of rotation (11), the housing main body (80) extending with a substantially constant cross-sectional shape along the axis of rotation (11), the cantilever (30) in the direction of the axis of rotation (11) displaceably protrudes from the housing (20), being in screwed engagement with the threaded spindle (41), characterized in that a separate intermediate plate (50; 50') in the direction of the axis of rotation (11 ) is arranged between the housing main body (80) and the first end block (21), wherein at least one fastening screw (61) is provided which fastens the first end block (21) and the intermediate plate (50; 50') in the direction of the axis of rotation (11) interspersed with being screwed into the housing main body (80), the pivot bearing (24) being interposed by a clamping force of the at least one fastening screw (61) between the first end block (21) and the intermediate plate (50; 50') is clamped.

Description

The invention relates to an actuator according to the preamble of claim 1.

From the DE 10 2013 214 733 A1 an actuator is known which is designed in the manner of an electric cylinder. The actuator has a housing from which a cantilever protrudes in a displaceable manner in the direction of an axis of rotation. The cantilever is driven by means of a threaded spindle which is mounted in a first end block of the housing by means of a pivot bearing so as to be rotatable with respect to the axis of rotation. This pivot bearing is attached to the first end block by means of a ring nut. This ring nut transmits the axial force of the screw drive. In particular, if a planetary screw drive is used as the screw drive, which can transmit very high axial forces, the ring nut must be tightened with an extremely high torque. This makes assembly of the actuator considerably more difficult. It has also been shown that, in the event of a repair, it is sometimes impossible to disassemble the ring nut again without causing significant damage to the actuator. Note also the intermediate plate with the pivot pins, which is arranged on the opposite side of the first end block from the housing main body.

One advantage of the actuator according to the invention is that the ring nut, which is difficult to assemble, for fastening the pivot bearing can be dispensed with entirely. This considerably simplifies the assembly and disassembly of the actuator. Furthermore, fluid channels and/or pivot pins can be provided inexpensively with the comparatively compact intermediate plate. These are only required for some of the possible variants of the actuator. The larger parts such as the housing main body and the first end block can be made the same for all variants of the actuator. A large variety of variants of the actuator can thus be provided at low cost.

According to claim 1, it is proposed that a separate intermediate plate is arranged in the direction of the axis of rotation between the housing main body and the first end block, wherein at least one fastening screw is provided which penetrates the first end block and the intermediate plate in the direction of the axis of rotation, being screwed into the housing main body is, wherein the pivot bearing is clamped by a clamping force of the at least one fastening screw between the first end block and the intermediate plate. The housing may include a second end block, the first and second end blocks being disposed at opposite ends of the housing main body in the direction of the axis of rotation. Preferably four mounting screws are provided, most preferably arranged to define the corners of a square.

Advantageous developments and improvements of the invention are specified in the dependent claims.

It can be provided that the intermediate plate has at least one fluid channel, which connects an outer peripheral surface of the intermediate plate with respect to the axis of rotation with an end face of the intermediate plate pointing towards the main body of the housing in the direction of the axis of rotation. Lubricating oil can be filled into the interior of the housing via the fluid channel in order to lubricate and cool the screw drive. In particular, when a planetary screw drive is used as the screw drive, it is advantageous to fill the volume of the interior space mentioned, for example up to 80%, with lubricating oil in order to dissipate the frictional heat generated in the screw drive. This can be safely dissipated via the lubricating oil. Such a lubricating oil filling is only required for some variants of the actuator. The corresponding special machining is particularly easy to carry out on the intermediate plate. On the outer peripheral surface, the fluid channel is preferably provided with an internal thread into which a screw plug or a connection fitting can be screwed in a fluid-tight manner.

Provision can be made for the intermediate plate to have two fluid channels which are arranged diametrically opposite one another with respect to the axis of rotation. One fluid channel can thus be used to drain the lubricating oil, while the other is used to supply the lubricating oil. Both fluid channels are preferably equipped with the same internal thread, so that their function can be exchanged at will.

Provision can be made for a cross-sectional profile of the housing main body to be designed in such a way that it does not completely cover an outlet opening of the at least one fluid channel on the end face of the intermediate plate. This is the only way to ensure that lubricating oil can be filled into the interior of the housing via the fluid channel. Preferably, the mouth opening is not covered at all by the cross-sectional profile of the main body.

Provision can be made for two circular-cylindrical pivot pins to be fixedly arranged on the intermediate plate, which together define a pivot axis which is aligned perpendicularly to the axis of rotation. Such pivot pins are only present in individual variants of the actuator seen. They too can be provided particularly inexpensively on the intermediate plate according to the invention. It is also ensured there that they can transmit the forces occurring during operation. A thickness of the intermediate plate in the direction of the axis of rotation is preferably designed to be greater than a diameter of the pivot pins. The ones from the DE 10 2013 214 733 A1 known, comparatively thin intermediate plate is very flexible. Preferably, the pivot axis intersects the axis of rotation.

Provision can be made for the two fluid channels and the two pivot pins to be offset from one another by 90° with respect to the axis of rotation. This means that both the pivot pins and the fluid channels are easily accessible.

It can be provided that a sealing ring is accommodated in the intermediate plate, which is in sealing engagement with a sealing surface on the threaded spindle, with an interior space of the housing delimited in sections by the main body of the housing being at least 20% filled with lubricating oil. This ensures that the lubricating oil remains in the interior. The seal that may be provided on the pivot bearing does not have to be matched to the lubricating oil in the interior and can be chosen to be the same for all variants of the actuator. The sealing surface is preferably circular-cylindrical with respect to the axis of rotation. It is preferably formed by a separate component which is firmly connected to the threaded spindle. Said component is preferably designed in the form of a circular-cylindrical sleeve.

At least one connecting screw can be provided, which passes through the intermediate plate, being screwed into the first end block. The first end block, the pivot bearing and the intermediate plate form a pre-assemblable assembly which is fastened as a whole to the main body by means of the fastening screws. In addition, the at least one connecting screw simplifies the assembly of the pivot bearing in the first end block. The connecting screw preferably has a head which is countersunk in a depression in the intermediate plate.

Provision can be made for the intermediate plate to be provided with a centering extension which is circular-cylindrical with respect to the axis of rotation and which rests on the end face of the pivot bearing. The pivot bearing is preferably clamped between the centering extension and the first end block. An outside diameter of the centering extension and an outside diameter of the pivot bearing are preferably the same.

A second end block can be provided, with the first and second end blocks being arranged at opposite ends of the housing main body in the direction of the axis of rotation, with the main housing body being penetrated by an oil return channel in the direction of the axis of rotation, the oil return channel being connected via deflection channels in the second end block and in the intermediate plate is connected to an interior of the housing, in which the cantilever is arranged in sections. The extension arm is preferably in screwed engagement with the threaded spindle via a nut, the nut being arranged in the interior. The interior space is preferably at least partially filled with lubricating oil. The lubricating oil displaced by the nut as it moves can flow with little resistance to the opposite side of the nut via the oil return channel. At this time, it is cooled in the oil return passage from the case main body. A similar oil return is from the DE 10 2015 221 712 A1 known. In the housing main body, the oil return channel is preferably arranged completely separately from the inner space.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

• 1 eine perspektivische Ansicht eines Aktuators gemäß einer ersten Ausführungsform der Erfindung;
• 2. einen Längsschnitt eines Aktuators gemäß einer zweiten Ausführungsform der Erfindung;
• 3 einen vergrößerten Abschnitt von 2 im Bereich der Zwischenplatte;
• 4 eine perspektivische Ansicht der Zwischenplatte nach 2 vom Gehäusehauptkörper her;
• 5 eine perspektivische Ansicht der Zwischenplatte nach 2 vom ersten Endblock her;
• 6 einen Querschnitt des Hauptkörpers.

The invention is explained in more detail below with reference to the accompanying drawings. It shows:

• 1 a perspective view of an actuator according to a first embodiment of the invention;
• 2 . a longitudinal section of an actuator according to a second embodiment of the invention;
• 3 an enlarged section of 2 in the area of the intermediate plate;
• 4 a perspective view of the intermediate plate 2 from the case main body;
• 5 a perspective view of the intermediate plate 2 from the first end block;
• 6 a cross section of the main body.

1 12 shows a perspective view of an actuator 10 according to a first embodiment of the invention. The actuator 10 includes a housing 20 which is elongated along an axis of rotation 11 . A cantilever 30 protrudes from the housing 20 in the direction of the axis of rotation 11 and can be moved along the axis of rotation 11 by means of the drive motor 25 . The drive Motor 25 is preferably an electric motor which is in rotary drive connection with the threaded spindle, for example by means of a toothed belt or directly via a clutch. The arrangement of the drive motor 25 in 1 on housing 20 is one of several possible variants.

The case 20 includes a case main body 80 made of, for example, aluminum by extrusion. The housing main body 80 is formed into a tubular shape extending along the rotation axis 11 with a constant cross-sectional shape. Housing 20 includes first and second end blocks 21; 22 which are fixed in the direction of the rotation axis 11 at opposite ends of the housing main body 80 by means of fixing screws (#61 in 4 ). The second end block 22 forms a linear slide bearing for the boom 30, namely for its tubular section 31, which is designed here as a circular-cylindrical tube. An end head 32 is arranged at the free end of the tubular section 31, which in the present case is designed as an articulated head, with further variants being possible.

In the present case, two blowers 70 are provided on the outside of the housing main body 80 and are fixed to the housing main body 80 opposite to one another. These suck in air from the environment by means of an electrically driven fan wheel and press it into the cooling channels (No. 82 in 6 ) in the main housing body 80. In the intermediate plate 50 and/or in the second end block 22, curved deflection channels are provided, which each connect two cooling channels in the main housing body 80 to one another. Further, air outlets 71 are provided on the case main body 80, each connected to an associated cooling duct. There, the air conveyed into the cooling ducts by the fans 70 can exit the cooling ducts again.

A separate intermediate plate 50 is arranged between the housing main body 80 and the first end block 21 . This is provided with two pivot pins 63 which are fixedly arranged on opposite sides of the intermediate plate 50 . The pivot pins 50 each have a circular-cylindrical outer peripheral surface, defining a common pivot axis 64 . In the present case, the pivot axis 64 is arranged perpendicularly to the axis of rotation 11 , intersecting the axis of rotation 11 . Both pivot pins 63 are each pivotally received in an associated bearing block 13 .

In the first embodiment of the invention, the intermediate plate 50 has three functions, namely supporting the pivot bearing (No. 24 in 2 ), providing the fluid channels (No. 53 in 3 ) and the inclusion of the pivot pins 63.

2 shows a longitudinal section of an actuator 10' according to a second embodiment of the invention 1. The second embodiment differs from the first embodiment only in that the pivot pins (no. 63 in 1 ) are omitted, with the intermediate plate 50' being made correspondingly thinner. All other comments on 1 thus also apply to the second embodiment. All comments on the 2 until 6 apply in a corresponding manner to the first embodiment. In the 1 until 6 Identical or corresponding parts are marked with the same reference numbers.

Inside the housing 20 there is a threaded spindle 41 which extends along the axis of rotation 11 . The threaded spindle 41 is rotatably mounted in the first end block 21 with respect to the axis of rotation 11 . The corresponding rotary bearing 24 in the present case comprises two angular contact ball bearings, with more individual bearings being able to be provided depending on the desired axial force. At the end facing away from the pivot bearing 24 , the threaded spindle 42 protrudes into the tubular section 31 of the boom 30 , passing through a nut 50 which is firmly connected to one end of the boom 30 . The nut 50 and the threaded spindle 42 together form a screw drive 40, which is designed here as a planetary screw drive.

The intermediate plate 50 ′ is arranged between the housing main body 80 and the first end block 21 as in the first embodiment.

The housing main body 80 is provided with an oil return passage 86 which is in a constant circular cross-sectional shape (see FIG 6 ) extends over the entire length of the housing main body 80. A deflection channel 72 is provided in the second end block 22 and in the intermediate plate 50 ′, which channel connects an associated end of the oil return channel 86 to the interior 12 of the housing 20 . The free cross section of the interior is essentially completely filled by the nut 50 . Thus, a movement of the nut 50 is accompanied by a movement of the lubricating oil, which is located in the interior. Preferably about 80% of the volume of the interior space is filled with lubricating oil. The lubricating oil can flow essentially unhindered from one side to the other side of the nut via the oil return channel 86 . At the same time, it is particularly well cooled in the oil return channel 86 by the housing main body 80 .

3 shows an enlarged portion of 2 in the area of the intermediate plate 50'. The win The spindle 41 is also provided with an external thread in the area of the rotary bearing 24, via which it can be connected to the nut (No. 50 in 2 ) is in screw engagement. This is to ensure that the threaded spindle 41 is not weakened by the pivot bearing 24 . A bearing carrier 45 is screwed onto said external thread, which bears the pivot bearing 24 with a circular-cylindrical outer peripheral surface with respect to the axis of rotation 11 , which bearing comprises two angular contact ball bearings in the present case. The rotary bearing 24 is firmly clamped to the threaded spindle 41 and the bearing bracket 45 by means of a ring nut 46 .

A separate sealing sleeve 44 is firmly mounted with a press fit on the outer peripheral surface of the bearing bracket 45 . The sealing sleeve 44 forms a circular-cylindrical sealing surface 43 with respect to the axis of rotation 11, on which a separate sealing ring 60 runs. In the present case, the sealing ring 60 is designed as a radial shaft sealing ring. The sealing ring 60 is firmly accommodated in an adapted recess of the intermediate plate 50'. The sealing ring 60 is intended to ensure that the lubricating oil located in the interior 12 of the housing 20 does not escape from the housing 20 via the pivot bearing 24 . The sealing ring 60 is installed in such a way that the overpressure that may be present in the interior increases the sealing effect of the sealing ring 60 .

The intermediate plate 50 ′ has a centering extension 58 which is circular-cylindrical with respect to the axis of rotation 11 and whose outer diameter is equal to the outer diameter of the pivot bearing 24 . The pivot bearing 24 is braced against the first end block 21 with the centering extension 58 , it being accommodated in a circular-cylindrical recess of the first end block 21 . Using the connecting screws (#62 in 4 ) passing through the intermediate plate 50' while being screwed into the first end block 21, the pivot bearing 24 is pushed into the first end block 21. As a result, the first end block 21 forms a pre-mountable assembly with the intermediate plate 50', which is mountable to the case main body 80 as a whole. Mounting screws (#61 in 4 ) are used, which pass through the first end block 21 and the intermediate plate 50', being screwed into an associated screw channel (No. 81 in 1 ) of the case main body 80 are screwed. The fastening screws are designed in such a way that the axial forces occurring during operation can be safely transmitted. The connecting screws are essentially not involved in the transmission of the axial force and only have the function explained above as part of the assembly.

Furthermore, reference should be made to the two fluid channels 53 in the intermediate plate 50 ′, which are each composed of a plurality of circular-cylindrical bores which run parallel or perpendicular to the axis of rotation 11 . About the in 3 Upper fluid channel 53 can be supplied to the interior 12 lubricating oil. For this purpose, a connection fitting 66 is screwed into an internal thread 54 of the fluid channel 53, which is located on an outer peripheral surface 51 of the intermediate plate 50'. The fluid channel 53 leads in each case to an orifice 55 which is arranged on an end face 52 of the intermediate plate 50'. So that the orifice opening 55 is not covered by the main housing body 80 and thus closed, a recess adapted to the orifice opening 55 (No. 83 in 6 ) intended.

the inside 3 The lower fluid channel is closed with a screw plug 65 in the present case. At the same time, it forms the deflection channel 72, via which the lubricating oil can flow from the interior space 12 into the oil return channel 86 and vice versa. Depending on the selected installation position of the actuator 10', the connection fitting 66 can also be screwed in there.

4 Figure 12 shows a perspective view of the intermediate plate 50' 2 from the case main body.

5 Figure 12 shows a perspective view of the intermediate plate 50' 2 from the first end block. The intermediate plate 50' is essentially in the form of a flat plate with a constant thickness. The cross-sectional shape of the outer peripheral surface is square with rounded corners, and the outer peripheral surface 51 is continuous with the case main body. The intermediate plate 50' has four first openings 73 in the corners for the fastening screws 61 explained above, which transmit the axial forces of the screw drive. The circular-cylindrical first openings 73 are each aligned with a screw channel (No. 81 in 6 ) arranged. Adjacent to the first openings 73 there is a second opening 74 for the connecting screws 62 explained above. The second openings 74 are each provided with a countersink on the side of the housing main body, so that the head of the connecting screw 62 does not protrude beyond the intermediate plate 50'.

In 4 A fluid channel 53 can be seen, which opens out with an internal thread 54 on the outer peripheral surface 51, it opening out with an orifice opening 55 on the end face 52 of the intermediate plate 50'.

In 5 the above-mentioned centering projection 58 can be seen, on the inside of which there is a recess for the seal (No. 60 in 3 ) is arranged.

The intermediate plate according to the first embodiment is different from that in 4 and 5 illustrated intermediate plate 50 'according to the second embodiment thicker only in the direction of the axis of rotation 11, wherein on the outer peripheral surface 51 the separate pivot pins (No. 63 in 1 ) are firmly attached.

6 12 shows a cross section of the case main body 80. The case main body 80 is preferably made of aluminum by extrusion, and the cross-sectional shape is optimized according to this manufacturing method. In the 6 The cross-sectional shape shown is constant over the entire length of the case main body 80 . The outer shape of the case main body 80 is square with rounded corners. A screw channel 81 is provided at each of the four corners, into which an internal thread is cut in order to fasten the first or second end block there with a fastening screw (No. 61 in 4 ) to screw. The two T-slots 85 on the outside of the housing main body 80 serve, among other things, to accommodate sensors or limit switches with which the position of the boom or the nut can be detected.

The inner shape is circular with respect to the axis of rotation 11, with four trapezoidal slideways 84 being provided for slide rails on the nut, which prevent the nut from rotating relative to the housing.

In addition, a total of eight cooling channels 82 are provided, which are provided with cooling ribs on their inside in order to increase the heat-transferring surface. Any two cooling ducts 82 are connected to each other via curved ducts in the intermediate plate and/or in the second end block, with the fans (No. 70 in 1 ) Ambient air can be blown into the cooling channels 82.

The recess 83 ensures that the housing main body 80 has the orifice openings (No. 55 in 4 ) of the fluid channel is not covered, so that they are free for the passage of lubricating oil.

Next is in 6 the above-mentioned oil return channel 86 can be seen, which in the present case has a circular cross-sectional shape.

Reference List

10

Actuator (first embodiment)

10'

Actuator (Second Embodiment)

11

axis of rotation

12

inner space

13

bearing block

20

Housing

21

first end block

22

second end block

24

pivot bearing

25

drive motor

30

boom

31

tubular section

32

end head

40

screw drive

41

lead screw

42

Mother

43

Sealing surface on the threaded spindle

44

sealing sleeve

45

bearing carrier

46

ring nut

50

Intermediate Plate (First Embodiment)

50'

Intermediate Plate (Second Embodiment)

51

Outer peripheral surface of the intermediate plate

52

face of the intermediate plate

53

fluid channel

54

Internal thread of the fluid channel

55

Orifice of the fluid channel

58

centering extension

60

sealing ring

61

mounting screw

62

connecting screw

63

trunnion

64

pivot axis

65

Screw

66

connection fitting

70

fan

71

air outlet

72

deflection channel

73

first breakthrough

74

second breakthrough

80

case main body

81

Screw channel with internal thread for fastening screw

82

cooling channel

83

Recess for muzzle opening

84

slideway

85

T-slot

86

oil return channel

Claims (10)

An actuator (10; 10') having a housing (20), a cantilever (30) and a lead screw (41), said housing (20) comprising a first end block (21) and a housing main body (80), said lead screw ( 41) in the region of the first end block (21) by means of a rotary bearing (24) so as to be rotatable with respect to an axis of rotation (11), the housing main body (80) extending with a substantially constant cross-sectional shape along the axis of rotation (11), the cantilever (30) in the direction of the axis of rotation (11) displaceably protrudes from the housing (20), being in screwed engagement with the threaded spindle (41), characterized in that a separate intermediate plate (50; 50') in the direction of the axis of rotation (11 ) is arranged between the housing main body (80) and the first end block (21), wherein at least one fastening screw (61) is provided which fastens the first end block (21) and the intermediate plate (50; 50') in the direction of the axis of rotation (11) interspersed with being screwed into the housing main body (80), the pivot bearing (24) being interposed by a clamping force of the at least one fastening screw (61) between the first end block (21) and the intermediate plate (50; 50') is clamped. actuator (10; 10'). claim 1 , wherein the intermediate plate (50; 50') has at least one fluid channel (53) which has an outer peripheral surface (51) of the intermediate plate (50; 50') with respect to the axis of rotation (11) with a direction of the axis of rotation (11) to the housing main body ( 80) pointing end face (52) of the intermediate plate (50; 50). actuator (10; 10'). claim 2 , wherein the intermediate plate (50; 50') has two fluid channels (53) which are arranged diametrically opposite one another with respect to the axis of rotation (11). actuator (10; 10'). claim 2 or 3 A cross-sectional profile of the housing main body (80) is designed such that it does not completely cover an orifice (55) of the at least one fluid channel (53) on the end face (52) of the intermediate plate (50; 50'). Actuator (10) according to one of the preceding claims, wherein two circular-cylindrical pivot pins (63) are fixedly arranged on the intermediate plate (50), which together define a pivot axis (64) which is aligned perpendicularly to the axis of rotation (11). Actuator (10) after claim 5 , referring back to claim 3 , wherein the two fluid channels (53) and the two pivot pins (63) are arranged offset from one another by 90° with respect to the axis of rotation (11). Actuator (10; 10') according to one of the preceding claims, wherein a sealing ring (60) is accommodated in the intermediate plate (50; 50'), which is in sealing engagement with a sealing surface (43) on the threaded spindle (41), wherein a the interior (12) of the housing (20), which is delimited in sections by the main body (80) of the housing, is at least 20% filled with lubricating oil. Actuator (10; 10') according to any one of the preceding claims, wherein at least one connecting screw (62) is provided, which passes through the intermediate plate (50; 50'), being screwed into the first end block (21). Actuator (10; 10') according to one of the preceding claims, wherein the intermediate plate (10; 10') is provided with a centering extension (58) which is circular-cylindrical with respect to the axis of rotation (11) and bears on the end face of the pivot bearing (24). An actuator (10; 10') according to any one of the preceding claims, wherein a second end block (22) is provided, the first and second end blocks (21; 22) being at opposite ends of the housing main body (80) in the direction of the axis of rotation (11). are arranged, wherein the main housing body (80) has an oil return channel (86) passing through it in the direction of the axis of rotation (11), the oil return channel (86) being connected via deflection channels (72) in the second end block (22) and in the intermediate plate (50; 50 ') is connected to an interior space (12) of the housing (20), in which the cantilever (30) is arranged in sections.

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