EP1777068A2 - Direct drive of a printing machine - Google Patents

Abstract

u The device comprises an electro-motor (3) whose rotor (14) is arranged coaxially to the cylinder (1) and is firmly connected with it. It has a stator (15) and a frame construction (2) in which the cylinder is axially, slidably mounted and held. The rotor and the stator are dimensioned in such a way with the cylinder and coupled relative to the frame construction. The stator is fixed to receiving housing (9) of the electro-motor on an outer ring (7) of the bearing of the cylinder in the frame construction~s roller bearing (5). There may be a linear guide (8) that is slidable in the bearing of the cylinder~s roller bearing perpendicular to the rotation axis (A) of the cylinder.

Description

Field of the invention

The invention relates to a device for driving a cylinder of a printing press, with an electric motor whose rotor is arranged coaxially to the cylinder of the printing press and rotatably connected thereto, and whose stator is held on a frame structure in which the cylinder is mounted axially displaceable. Such a device is for example from the DE 102 19 903 A1 known.

Background of the invention

Another, from the EP 1 277 575 B1 known printing machine drive is part of an offset printing machine, which has at least one printing unit with at least one form and a transfer cylinder, wherein a lateral displacement of the forme cylinder can be provided. Since the rotor of the forme cylinder directly driving electric motor is rigidly connected to the forme cylinder and thus in its lateral, ie axial displacement is shifted with the stator of the motor is stationary, a change in the performance of the electric motor is to be assumed in an axial displacement of the forme cylinder.

Object of the invention

The invention has for its object to provide an electric direct drive for a cylinder of a printing press, in which there is at most a slight dependence between the axial position of the cylinder and the properties of the electric drive.

Summary of the invention

This object is achieved by a device for driving a cylinder of a printing press with the features of claim 1. In this device is an electric direct drive with an electric motor, the rotor is arranged relative to the cylinder of the printing press not rotatable and coaxial therewith , The stator of the electric motor is held on a frame construction of the printing press, wherein the cylinder is mounted axially displaceable in the frame structure. The gap space formed between the rotor and the stator is constant with respect to both the gap width and the length measured in the axial direction of the cylinder at each possible position of the cylinder during normal operation of the printing press. This is achieved by the geometry of the stator and rotor and / or by the way the rotor is coupled to the cylinder and the stator to the frame construction. As a gap between the stator and rotor is generally understood that volume range between the stator and the rotor, in the exact radial direction, based on the axis of rotation of the cylinder of the printing press and the rotor, on the one hand by the rotor and on the other hand by the stator provided for direct electrical drive of the cylinder Motors is limited. In the simplest case have stator and rotor of the electric motor a different length measured in the axial direction, so that each axis of rotation of the cylinder intersecting, arranged perpendicular to this axis straight line which intersects the axially shorter of the two parts stator and rotor, in each operating state of the electric motor, ie in any possible axial positioning of the Cylinder, even in the axial direction longer of the parts stator and rotor cuts. Other ways to keep the gap between the stator and rotor constant, are by a variability of the axial position of the rotor or the stator relative to a rotor or the stator bearing member, ie relative to the rotatable cylinder or relative to the frame structure connected Housing of the electric motor, given. The housing of the electric motor accommodating the stator is fastened to an outer ring of a roller bearing serving to mount the cylinder in the frame construction.

In all cases, performance data of the electric direct drive such as torque and angular acceleration are not dependent on the displacement of the cylinder in the direction of its axis of rotation. This also applies to designs in which the cylinder is displaceable by means of a linear guide perpendicular to its axis of rotation in the frame construction.

According to a first embodiment, the rotor of the cylinder directly driving electric motor is guided axially displaceable relative to the cylinder of the printing press. The stator is also fixedly arranged in the housing of the electric motor, which is connected directly or indirectly, in particular via a linear guide, which allows an adjustment of the cylinder perpendicular to its axis to the frame construction of the printing press. Preferably, the rotor of the electric motor in the radially inner region of a particular made of non-ferrous metal bushing, which is mounted axially displaceably on the cylinder or a pin fixedly connected thereto. Such a bushing, in particular non-ferrous metal bush, may also be provided in embodiments in which the rotor is held immovably on the cylinder or a component firmly connected thereto. Irrespective of the extent to which an axial displaceability of the rotor relative to the cylinder is provided is, the bearing of the rotor is designed such that no or only a negligible small rotation of the rotor relative to the cylinder is possible.

In order to simultaneously allow axial displacement of the rotor in such a rotationally fixed bearing of the rotor on the cylinder or a component rigidly connected thereto, a roller bearing of the rotor is provided in an advantageous embodiment, as it can in principle also be used in conventional linear technology products. Likewise, however, a sliding bearing is feasible, which allows an adjustability of the rotor relative to the cylinder only in the axial direction. In each of the aforementioned cases, a bearing is provided according to an advantageous development, which defines the axial position of the rotor relative to the housing of the electric motor, regardless of the axial positioning of the cylinder. This bearing is preferably a deep groove ball bearing whose bearing rings are fixedly connected to the rotor or to the stator of the electric motor.

According to an alternative embodiment, the rotor of the electric motor is connected by means of at least one axially compliant, at the same time rigid in the circumferential direction connecting element with the cylinder or a rigidly attached to this part. In this case, the connecting element is in its, relative to the axis of rotation of the cylinder, axially outer region with the rotor and in the axially inner region with the cylinder or rigidly attached to this part, in particular pin connected. The resilient connecting element between the cylinder and the rotor preferably has a spring action in the axial direction. The forces acting thereon in the axial direction on the rotor are less than the electromagnetic forces which likewise act in the axial direction and which occur during operation of the electric motor. In this way, with an axial displacement of the cylinder, the rotor is centered at least approximately relative to the stator. Under no circumstances is the rotor displaceable beyond the stator in the axial direction. In manufacturing technology advantageously, the connecting element by laser welding to the rotor and / or with the cylinder or a rigidly attached to this part connected. Likewise, laser welding process can be used in the manufacture of the connecting element itself.

Particularly vibration-damping properties of the connecting element can be achieved by this is made of a composite material, in particular a sandwich composite of sheet metal and plastic.

A further embodiment of the invention provides that the stator is guided axially displaceable relative to a housing of the electric motor connected to the frame construction of the printing press. The rotor is in this case rigidly connected to the cylinder of the printing press. Between the end faces of the longitudinally displaceable in the housing of the electric motor mounted stator and these opposite inner faces of the housing are preferably elements with resilient properties, in particular in each case an O-ring arranged. As long as the electric direct drive is not actuated, thus centering the stator within the available displacement path. By contrast, when the electric motor is running, the axial position of the stator is determined mainly by the forces acting between the stator and the rotor. In this case, the stator always aligns so relative to the rotor that the geometry of the gap formed between the stator and rotor is independent of the axial position of the cylinder. In order to position the stator particularly precisely relative to the rotor, an axial bearing can be provided which keeps the stator always in an axially unchangeable position relative to the rotor, independently of the operation of the electric motor. A particularly easy displacement of the stator in the longitudinal direction, i. in the axial direction, is given in the case of a rolling bearing of the stator in the housing of the electric motor. Corresponding linear guide elements preferably have an adjustable bias, so that the compliance of the leadership of the stator can be minimized in the circumferential direction.

According to a further embodiment which can be combined with the above-described exemplary embodiments, the electric direct drive of the printing machine cylinder has an intrinsically safe brake, ie, in the event of a power failure. interacting Friction linings of this brake are fastened on the one hand to the rotor and on the other hand to the housing of the electric motor. If the brake, in particular by means of compressed air, solved, the rotor is moved in the housing of the electric motor in the axial direction. A displacement of the rotor in the opposite direction and thus a closing of the brake is preferably effected by means of spring force.

Several embodiments of the invention will be explained in more detail with reference to a drawing. Herein show:

Short description of the drawing

FIG. 1

A first embodiment of an electric direct drive of a printing press cylinder,

FIG. 2

A second embodiment of an electric direct drive of a printing press cylinder,

Figure 3 a and b

Details of the direct electrical drive of a printing press cylinder according to FIG. 2,

Figure 4 a and 4

Details of a third embodiment of an electric direct drive of a printing machine cylinder in views analogous to Figure 3 a and b,

FIG. 5

A fourth embodiment of an electric direct drive of a printing press cylinder,

FIG. 6

A fifth embodiment of an electric direct drive of a printing press cylinder,

Figure 7 a and b

a sixth embodiment of an electrical Direct drive of a printing press cylinder,

FIG. 8

a seventh embodiment of an electric direct drive of a printing press cylinder, and

Figure 9 a and b

an eighth embodiment of an electric direct drive of a printing press cylinder.

Detailed description of the drawing

Figures 1 to 9a, 9b each show a schematic view of various embodiments of an electric direct drive of a printing press. This has a rotatable about an axis A cylinder 1, which is mounted in a frame structure 2 of the press not shown and directly driven by an electric motor 3. The cylinder 1 is repeatedly stepped to the front side 4 with decreasing diameter, wherein a rotation about the axis A enabling rolling bearing 5 is arranged on an annular portion 6 of the cylinder 1. The outer ring 7 of the rolling bearing 5, namely cylindrical roller bearing is not directly attached to the frame structure 2, but connected to this via a linear guide 8, which allows an adjustment of the cylinder 1 perpendicular to the axis of rotation A. On the outer ring 7, the housing 9 of the electric motor 3 is further attached. With each adjustment of the cylinder 1 perpendicular to the axis of rotation A thus the electric motor 3 is automatically adjusted with. Separate facilities for tracking the electric motor 3 are not required.

Adjacent to the end face 4 of the cylinder 1 is a pin 11, also referred to as a shaft journal extension, whose axis of rotation is identical to the axis A of the cylinder 1. In order to hold the pin 11 rigidly on the cylinder 1, an edge 12 of the pin 11 engages around an annular portion 10 of the cylinder 1 bordering the end face 4. The pin 11, which is fixed on the cylinder 1 by means of a tensioning device 13, carries the rotor 14 the electric motor 3.

In contrast, the stator 15 of the electric motor 3 designed as a torque motor is connected to the outer ring 7 of the roller bearing 5 via the housing 9. The entire composite comprising the cylinder 1, the pin 11 and the rotor 14 is displaceable along the axis of rotation A.

This axial displacement is given by the nature of the rolling bearing 5. A separate linear guide for the displacement of the cylinder 1 along the axis A, however, is not provided.

As can be seen from FIG. 1, the axial length L _{R of} the rotor 14 is less than the length L _{S of} the stator 15 measured in the same direction. The lengths L _R , L _{S of} the parts 14, 15 of the electric motor 3 are dimensioned such that no possible operating state of the rotor 14 projects beyond the stator 15 in the axial direction. Thus, a gap formed between the rotor 14 and stator 15 16 remains constant under all possible conditions of normal operation of the electric motor 1. All relevant characteristics of the electric motor 3, such as the speed-dependent relationship between power consumption and torque, are thus independent of the axial positioning of the cylinder 1. The gap width of the gap space 16 is denoted by s; the length of the gap space 16 is identical to the length L _{R of} the rotor 14.

The rotor 14 has an inner part 17 directly surrounding the pin 11 and an outer part 18, which are connected to one another by means of a tensioning device 19. The tensioning device 19, which fixes the rotor 14 rigidly on the pin 11, comprises a number of screws 20 and wedges 21, wherein the screws 20 can be actuated through openings 22 of the housing 9.

The embodiment of Figure 2 also includes a permanent magnet excited synchronous motor as an electric motor 3. The rotor 14 of this electric motor 3 is not fixed rigidly on the pin 11, but mounted displaceably by means of a guide 23 in the direction of the axis of rotation A. The guide 23 comprises a fastened by means of a screw 24 on the pin 11 Sliding nut 25 on which a made of brass, a part of the rotor 14 forming bushing 26 slides. The rotor 14 is thus rotationally fixed despite axial displacement on the pin 11, and thus also rotatably relative to the cylinder 1 gefü h rt.

The forces occurring during operation of the electric motor 3 direct the rotor 14 in the axial direction always centric to the stator 15, as shown in Figure 2, from. If an axial displacement movement of the cylinder 1, also referred to as Seitenregisterverstellung performed, the rotor 14 moves relative to the cylinder 1, while maintaining its absolute position, i. the position relative to the frame structure 2, at least approximately at.

Both in the embodiment of Figure 1 and in the embodiment of Figure 2 is an end face plate 27 of the housing 9 at the same time as an assembly aid in the assembly of the electric motor 3. If necessary, it is also possible to replace the stator 15 and / or the rotor 14 of the electric motor 3 Without completely removing the electric motor 3 from the printing press.

Details of the electric motor 3 of Figure 2, which are relevant to the assembly, are shown in Figures 3 a and 3 b. An assembly pin 28 can be inserted through a bore 29 of the front plate 27 into a blind hole 30 of the rotor 14, so that the rotor 14 is positioned in the circumferential direction exactly relative to the pin 11. The sliding block 25 of Figure 3 b is constructed in two parts, with two wedge pieces 31, 32 by means of a screw 33, which is actuated through a bore 34 in the front panel 27, against each other can be moved. Thus, the game of the rotor 14 in the circumferential direction and the friction of the sliding block 25 in a groove 35 of the stator 14 is adjustable.

FIGS. 4 a and 4 b show a further developed variant of the bearing of the rotor 14 on the journal 11. In this case, each of the wedge pieces 31, 32 of the sliding block 25 is equipped with rolling elements 36, namely needles, whereby a so-called needle shoe 37 is formed , As the sliding block 25 in the embodiment According to the figures 3 a, b and the needle shoe 37 is arbitrarily biased. Due to the rolling bearing of the rotor 14, both a clearance-free in the circumferential direction and a low-friction and hysteresis-free storage in the axial direction is given.

Any axial displacement of the rotor 14 relative to the frame structure 2 is prevented by a deep groove ball bearing 38 whose bearing rings 39, 40 are firmly connected on the one hand to the front plate 27 and on the other hand to the rotor 14.

In the embodiment of Figure 5, the rotor 14 is not held directly on the pin 11, but coupled thereto by means of a flexible connecting element 41, which is connected on the one hand with the rotor 14 and on the other hand with a hub fixedly arranged on the pin 11 hub 42. The connecting element 41 comprises a plurality, in the axially front and in the axially rear region of the rotor 14 and the pin 11 held on the pin 11 by a play-free hub 42 arranged composite sheets 43. Each composite sheet 43 is constructed as a sheet metal / plastic / sheet sandwich component and per Laser welding with both the rotor 14, which surrounds the connecting element 41, and with the hub 42, which is arranged radially within the connecting element 41, materially connected. The connecting element 41 has elastically yielding properties exclusively in the direction of the axis of rotation A, so that the rotor 14 is rigidly mounted in the circumferential direction by means of the connecting element 41, but is resiliently mounted in the axial direction. Similar to the rotor 14 of FIG. 2 displaceably mounted by means of the bushing 26, the spring-mounted rotor 14 of FIG. 5 also positions itself automatically, solely on account of the electromagnetic forces occurring during operation of the electric motor 3, relative to the stator 15.

The embodiment of Figure 6 differs from the above-described embodiments substantially in that the stator 15 is mounted displaceably in the axial direction in the housing 9 of the electric motor 3, while the rotor 14 is rigidly connected to the pin 11 and thus also with the cylinder 1, for example, a plate, rubber, printing or transfer cylinder is connected. In order to center the stator 15 with the electric motor 3 switched off within the available displacement path, an O-ring 45 is disposed on both end faces 44 of the stator 15, which abuts against an inner end face 46 of the housing 9. Instead of an O-ring 45, for example, a coil spring or a leaf spring may be provided. The compliance of the O-rings 45 is sufficient to move in a side register adjustment, ie an axial displacement of the cylinder 1 and thus also of the rotor 14, the stator 15 by the electromagnetic forces occurring with. A rotation of the stator 15 relative to the housing 9 is prevented by a screwed into the stator 15 pin 47, which dips into a bore 48 in the housing 9. Although in contrast to the embodiments according to FIGS. 1 and 2, the stator length L _S and the rotor length L _{R are} identical, the gap space 16 between rotor 14 and stator 15 thus remains constant in each operating state in the exemplary embodiment according to FIG.

Figures 7 a and 7 b show a further development of the embodiment of Figure 6, wherein the stator 15 is guided longitudinally displaceable in the housing 9 by means of an adjustable needle shoe 49. Comparable with the embodiment of Figure 4a, b also has the needle shoe 49 of Figure 7 a, b two mutually displaceable wedge pieces 50, 51, so that the game of the stator 15 is adjustable in the circumferential direction. In particular, a bearing of the stator 15 is adjustable with bias. Even with completely assembled electric motor 3, the bias of the needle shoe 49 by means of a tool, not shown, changeable, which can be recognized through a bore 52 in the housing 9 to the needle shoe 49. Further, in a manner not shown, a bearing, in particular a rolling bearing, be provided between the rotor 14 and the stator 15, by means of which, similar to the embodiment of Figure 4 a, the axial position of the stator 15 is fixed relative to the rotor 14 unchangeable.

To dissipate the heat generated during operation of the electric motor 3, are located at the periphery of the stator 15 of a cooling medium, in particular water, through-flowable cooling channels 63 which are directly adjacent to the housing 9, wherein seals 64 are provided to seal against the housing 9. The cooling medium is passed through a bore 65 in the housing 9 into the cooling channels 63.

FIG. 8 shows a development of an electric direct drive in a printing machine, wherein an intrinsically safe brake 53 is integrated into the electric motor 3. The rotor 14 of the electric motor 3 is similar to the embodiment of Figure 2 by means of a sliding bearing slidably mounted on the pin 11 connected to the cylinder 1. On the side facing away from the cylinder 1 front side of the rotor 14 is a first brake pad 54, which cooperates with a second, attached to the inside of the front panel 27 brake pad 55. Without energy supply, the brake pads 54, 55 are pressed together by means of a helical spring designed as a compression spring 56 which surrounds the pin 11. Notwithstanding the representation, the compression spring 56 may be formed, for example, as a plate spring. In order to transmit a force from the compression spring 56 to the rotor 14 and thus to the brake pads 54, 55, one of the rotary decoupling rolling bearing 57 is disposed between the compression spring 56 and the rotor 14, wherein the arranged on the side of the compression spring 56 bearing ring 58th of the rolling bearing 57 is axially displaceable, but not rotatably mounted in the housing 9.

Another rolling bearing 59 transmits a force upon release of the brake 53 and is disposed between the front plate 27 of the housing 9 and the rotor 14. Here, arranged on the side of the front panel 27 bearing shell 60 of the rolling bearing 59 is not rigidly connected to the front panel 27, but coupled to a feed element 61 of an actuator 62 acting in the axial direction. The actuator 62 is in the illustrated embodiment, a compressed air actuated actuator, but may for example be designed as an electrically actuated or hydraulic actuator. In any case, a release of the brake 53 is only possible when energized to the actuator 62.

Figures 9 a and 9 b show an electric direct drive of a printing press, wherein the stator 15 of the electric motor 3 is fixedly disposed in the housing 9, while the rotor 14 by means of a compensating coupling 66 rotatably, but axially displaceable on the connected to the cylinder 1 Pin 11 is guided. For supporting the rotor 14 on the pin 11, a sliding bush 67 is provided. The axial position of the rotor 14 relative to the housing 9 is always constant even with an axial displacement, that is traversing movement of the pin 11. The compensating coupling 66 is disposed between the rotor 14 and a clamping set 68 mounted on the pin 11.

By means of a further compensating element 69, which is located on the front side of the pin 11, the rotational movement of the pin 11 is transferred with decoupling of axial movement components to an angle encoder 70, which is arranged outside of the housing 9. The angle sensor 70 is connected via a housing cap 71 with the rest of the housing 9.

LIST OF REFERENCE NUMBERS

1

cylinder

2

frame construction

3

electric motor

4

front

5

roller bearing

6

section

7

outer ring

8th

linear guide

9

casing

10

section

11

spigot

12

edge

13

jig

14

rotor

15

stator

16

gap

17

inner part

18

outer part

19

jig

20

screw

21

wedge

22

opening

23

guide

24

screw

25

sliding block

26

Rifle

27

front panel

28

mounting pin

29

drilling

30

blind

31

wedge

32

wedge

33

screw

34

drilling

35

groove

36

rolling elements

37

needle shoe

38

Deep groove ball bearings

39

bearing ring

40

bearing ring

41

connecting element

42

hub

43

composite sheet

44

front

45

O-ring

46

inner face

47

pen

48

drilling

49

needle shoe

50

wedge

51

wedge

52

drilling

53

brake

54

brake lining

55

brake lining

56

compression spring

57

roller bearing

58

bearing ring

59

roller bearing

60

bearing shell

61

feed element

62

actuator

63

cooling channel

64

poetry

65

drilling

66

Flexible coupling

67

bush

68

clamping set

69

compensation element

70

angle encoder

71

housing cap

A

axis

L _R

Length of the rotor

ls

Length of the stator

s

gap width

Claims (20)

Apparatus for driving a cylinder (1) of a printing machine, comprising an electric motor (3), the rotor (14) of which is arranged coaxially with the cylinder (1) and non-rotatably connected thereto, and whose stator (15) is fixed to a frame construction (2), in which the cylinder (1) is mounted axially displaceably, is held, wherein the rotor (14) and the stator (15) are dimensioned and coupled to the cylinder (1) or the frame structure (2) that at each during operation the printing machine possible axial displacement of the cylinder (1) between the stator (15) and rotor (14) formed gap space (16) both in gap width (s) and in terms of length remains constant, characterized in that the stator (15) receiving the housing (9) of the electric motor (3) is attached to an outer ring (7) of a bearing of the cylinder (1) in the frame construction (2) serving rolling bearing (5). Apparatus according to claim 1, characterized by a linear guide (8), by means of which the bearing of the cylinder (1) serving rolling bearing (5) perpendicular to the axis of rotation (A) of the cylinder (1) in the frame construction (2) is displaceable. Apparatus according to claim 1 or 2, characterized in that the rotor (14) relative to the cylinder (1) is guided axially displaceable. Apparatus according to claim 3, characterized in that the rotor (14) in the radially inner region of a bushing (26) which is mounted axially displaceably on the cylinder (1) or a permanently connected thereto pin (11). Apparatus according to claim 4, characterized in that the bush (26) is made of non-ferrous metal. Device according to one of claims 3 to 5, characterized in that the rotor (14) by means of a rolling bearing (36) relative to the cylinder (1) is guided longitudinally displaceable. Device according to one of claims 3 to 6, characterized by a bearing (38) which determines the axial position of the rotor (14) relative to a housing (9) of the electric motor (3) independently of the axial positioning of the cylinder (1). Apparatus according to claim 7, characterized in that as bearing (38) is provided a deep groove ball bearing whose bearing rings (39,40) with the rotor (14) or with the stator (15) of the electric motor (3) are firmly connected. Device according to one of claims 3 to 8, characterized in that the rotor (14) by means of at least one axially compliant, at the same time stiff in the circumferential direction connecting element (41), on the one hand, in a radially inner region, with the cylinder (1) or a rigidly connected to this fixed part (11,42) is connected, and on the other hand, in a radially outer region, with the rotor (14) is connected to the cylinder (1) is articulated. Apparatus according to claim 9, characterized in that the connecting element (41) is resilient in the axial direction. Apparatus according to claim 9 or 10, characterized in that the connecting element (41) made by laser welding and / or with the rotor (14) and / or with the cylinder (1) or a rigidly attached to this part (11,42) is. Device according to one of claims 9 to 11, characterized in that the connecting element (41) is made of a composite material. Apparatus according to claim 12, characterized in that the composite material of the connecting element (41) comprises a metallic material and a polymer material. Apparatus according to claim 1 or 2, characterized in that the stator (15) is guided axially displaceably relative to the housing (9) of the electric motor (3) connected to the frame structure (2). Apparatus according to claim 14, characterized in that between an end face (44) of the stator (15) and an inner end face (46) of the housing (9) an O-ring seal (45) is arranged. Apparatus according to claim 14 or 15, characterized by an axial bearing which holds the stator (15) in an axially unchangeable position relative to the rotor (14). Device according to one of claims 14 to 16, characterized in that the stator (15) is secured against rotation in the housing (9) is mounted. Apparatus according to claim 17, characterized in that the stator (15) by means of an adjustable sliding block (49) with a circumferentially of the stator (15) adjustable clearance or with bias in the housing (9) is mounted. Device according to one of claims 14 to 18, characterized in that the stator (15) has a housing (9) sealed to the cooling channel (63). Device according to one of claims 2 to 19, characterized by an intrinsically safe brake (53) for braking the composite of cylinder (1) and rotor (14).

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