AT524867B1 - Drive unit and molding machine with such - Google Patents

Abstract

Drive unit (1) for a shaping machine (2) comprising - a spindle (3) with at least one external thread (5), which at least one external thread (5) winds around the spindle (3) along a longitudinal axis (7) with a pitch, and - at least one spindle nut (4) with at least one internal thread (6), which at least one internal thread (6) extends along the longitudinal axis (7) with the same pitch as the at least one external thread (5) of the spindle (3), with between the at least one external thread (5) and the at least one internal thread (6) there is at least one ball channel (8) with balls (9) arranged therein for the transmission of force and/or movement between the spindle (3) and the at least one spindle nut (4). , wherein at least one supply device (10) for a fluid is provided in the area of one end (11) of the at least one ball channel (8), whereby the balls (9) in the area of the end (11) of the at least one ball channel (8) for liftingthe balls (9) can be flowed against by the fluid from the at least one external thread (5).

Description

description

The present invention relates to a drive unit for a molding machine with the features of claim 1, and a clamping unit, a plasticizing unit and a molding machine with such a drive unit.

[0002] Molding machines can be understood as meaning injection molding machines, transfer presses, presses and the like. Forming machines in which the plasticized mass is fed to an open mold are also entirely conceivable.

In the following, the prior art will be outlined using an injection molding machine. The same applies in general to shaping machines.

Generic drive units for molding machines include:

- a spindle with at least one external thread, which at least one external thread winds around the spindle along a longitudinal axis with a pitch, and

- at least one spindle nut with at least one internal thread, which at least one internal thread extends along the longitudinal axis with the same pitch as the at least one external thread of the spindle,

wherein between the at least one external thread and the at least one internal thread

at least one ball channel with balls arranged therein for force and/or movement transfer

transmission between the spindle and the at least one spindle nut.

It is known from the prior art to use drive units (also referred to as recirculating ball screws) in order to convert a rotational movement into a linear movement, for example in injection molding machines, with a spindle (usually mounted with linear movement and rotational or fixed) on a first component of the injection molding machine and a spindle nut (usually mounted fixedly or rotationally and linearly in a non-moving manner) is arranged on a second component of the injection molding machine that can be moved relative to the first component.

By forming a ball channel between the spindle and the spindle nut and balls arranged therein, a rotational movement can now be converted into a linear movement between the spindle and the spindle nut, whereby the first component moves linearly to the second component of the injection molding machine.

Such drive units (usually referred to as spindle drive and/or ball screw) are mostly used to convert a linear movement of a movable mold clamping plate to a fixed mold clamping plate of the clamping unit of an injection molding machine or also for the linear movement of a plasticizing unit of the injection molding machine.

During the movement between the spindle and the spindle nut, the balls in the ball channel are moved from the beginning of the ball channel towards the end of the ball channel or - more precisely: rolled - with balls continuously being removed from the end of the ball channel and having to be fed to the beginning of the ball channel It is common practice to implement a return device (usually a return channel) whereby the balls can be conveyed from the end of the ball channel to the beginning of the ball channel and a closed circuit of the balls is formed.

In order to remove or dissipate the balls at the end of the ball channel, it is known to perform so-called ball deflections, which deflect the balls from the ball channel at the end of the ball channel into the return device.

[0010] These ball deflections usually engage in the ball channel in the form of a finger in order to represent the smoothest possible deflection of the balls.

Such configurations are known, for example, from EP 3 809 013 A1, DE 10 2005 006697 A1 or DE 2805 141 A1.

Since very high loads are exerted on the balls in the ball channel, it is common

run these balls from a mostly very hard material, such as a hardened heat-treated steel.

The ball deflector is usually made of a plastic or a softer material than the balls themselves in order to avoid damage to the balls when they hit the ball deflector.

Damage to the balls, which serve as rolling bodies between the spindle and the spindle nut, can lead to uneven running, vibrations and/or damage between the spindle and the spindle nut.

Corresponding configurations of the ball deflector made of a softer material than the balls themselves, however, mean that the ball deflector is subject to wear over time, with the ball deflector wearing out until deflection is no longer possible without problems and jamming sometimes occurs of the balls at the end of the ball channel and blocking of the drive unit.

This wear of the ball deflection occurs on the one hand due to the continuous impact of the balls or rolling bodies on the ball deflection and on the other hand due to the high thermal loads that occur due to ongoing operation on the mostly filigree component of the ball deflection.

Especially when using quite large drive units, this has a negative effect on the maintenance work, with the entire drive unit usually being exchanged to change the ball deflection unit, which can usually only be dismantled and assembled with a great deal of effort due to their central arrangement can.

The object of the present invention is to provide a drive unit and a plasticizing unit, a clamping unit and/or a shaping machine with such a drive unit, in which the aforementioned disadvantages of the prior art are at least partially improved and/or the maintenance work is reduced and/or wear can be reduced and/or thermal stress can be reduced and/or smoother operation can be implemented.

This object is achieved according to the invention by a drive unit for a molding machine having the features of claim 1, a plasticizing or closing unit having the features of claim 13 and a molding machine having the features of claim 14.

[0020] According to the invention it is provided that a drive unit for a shaping machine

machine includes:

- a spindle with at least one external thread, which at least one external thread winds around the spindle along a longitudinal axis with a pitch, and

- at least one spindle nut with at least one internal thread, which at least one internal thread extends along the longitudinal axis with the same pitch as the at least one external thread of the spindle,

wherein between the at least one external thread and the at least one internal thread

at least one ball channel with balls arranged therein for force and/or movement transfer

transmission between the spindle and the at least one spindle nut consists, wherein at least

a supply device for a fluid in the region of one end of the at least one spherical channel

is provided, whereby the balls in the region of the end of the at least one ball channel

for lifting the ball from at least one external thread through which the fluid can flow.

By means of the supply device for a fluid, a ball can thus be lifted out of the ball channel in the region of the end of the ball channel and, for example, fed to a return device.

With a suitable design, it would even be conceivable for the balls to be lifted off simply by the flowing fluid as a result of the fluid flowing against them, without the balls coming into contact with a ball deflection device, for example, with the result that a resulting distortion

There is no wear on components to which the balls are fed in order to be lifted out of the ball channel.

[0023] However, embodiments with a ball deflection can be preferred.

Another advantage of the fluid flowing against the balls is that the balls can be lubricated on the one hand and cooled by the fluid on the other hand, which has an additional positive effect on wear of the drive unit (due to improved lubrication and/or cooling of the moving parts).

[0025] Thus, for example, an oil, a gaseous fluid (for example air, preferably compressed air) and/or a gaseous fluid loaded with oil can be used by the supply device.

The preamble of the present invention corresponding drive units can be referred to, for example, as a ball screw, ball screw, helical gear or ball screw drive.

[0027] Molding machines can be understood as meaning injection molding machines, transfer presses, presses and the like. Forming machines in which the plasticized mass is fed to an open mold are also entirely conceivable.

A device/drive unit according to the invention can be used in already known variants of the prior art, as already described in the introduction to the description, and can be installed later.

Measures and features that were described in the introduction in connection with the prior art can also be used within the scope of the invention.

Advantageous embodiments of the invention are defined in the dependent claims.

It can be provided that at least one return device is provided, which return device is designed to move the ball from the end of the at least one ball channel between the spindle and the at least one spindle nut to a start of the at least one ball channel between the spindle and the at least to guide a spindle nut.

[0032] Configurations are certainly conceivable in which the return channel is designed as a channel in or around the at least one spindle nut.

The at least one return device can preferably be designed as a channel which connects the end of the at least one ball channel with the beginning of the at least one ball channel by the shortest possible route in order to keep the distance to be covered by the balls through the return device as small as possible.

As mentioned, it can preferably be provided that at the end of the at least one ball channel, a ball deflection device - preferably made of a metallic material - is arranged, which ball deflection device is designed to deflect the balls from the at least one ball channel into at least one return device , Preferably wherein at least one feed device is arranged in the ball deflection.

It would be entirely conceivable, for example, for the at least one feed device to be arranged in an area of the ball deflector in which the balls from the at least one ball channel impinge on the ball deflector, with fluid being fed into this area in a manner via the feed device could be fed, so that the balls do not impinge directly on the ball deflection, but are first lifted from the at least one ball channel and then create gently on the ball deflection.

[0036] A “hard” impact of the balls on the ball deflection device can be avoided by such a corresponding configuration, with the balls being guided gently towards the ball deflection device, as a result of which wear on the ball deflection device is significantly reduced

can.

Due to the softer application of the balls to the ball deflection, it is possible to form the ball deflection from a metallic material, which has a longer service life compared to a plastic (and is subject to less wear at the same loads). This possibility of configuring the ball deflector from a metallic material results from the reduced risk of damage to the balls, since the balls no longer hit the ball deflector “hard” with a corresponding design by the feed device.

It can be provided that the at least one feed device has at least one fluid channel for flowing against the balls.

By providing at least one fluid channel, a fluidically ideal supply can be implemented via the at least one supply device of the fluid to the ball channel and the balls arranged therein, so that the fluid flow can be influenced in terms of its direction, its pressure, its speed and/or its volume flow can.

It can be provided that the at least one fluid channel in the area of the fluid channel end in the direction of the balls and/or the ball channel is designed with a nozzle and/or in the form of a nozzle, with an additional fluid flow in orientation, speed and/or pressure can be specifically influenced.

It is preferably provided that the at least one fluid channel for flowing against the balls is directed onto the balls—preferably onto a region of the balls facing the at least one external thread.

Alternatively or additionally, a fluid channel can first impinge on the external thread and be guided by it into the area between the balls and the external thread.

It can be provided that the ball deflection has a finger-shaped extension extending in the direction of the center of the at least one ball channel, preferably wherein the at least one fluid channel is arranged in the finger-shaped extension and at a finger end facing the center of the at least one ball channel in the at least one ball channel opens.

By providing the at least one fluid channel in a finger-shaped extension of the ball deflection device, a tempering, preferably cooling, effect of the fluid flowing through the fluid channel can also be used to temper the finger-shaped extension, preferably to cool it.

As mentioned, it can be provided that the fluid is compressed air, lubricating oil and/or compressed air charged with lubricating oil.

As lubricating oils, for example, all common industrial lubricants (preferably oils or greases) can be used, which are used from the prior art—particularly preferably in the field of ball bearings.

It can preferably be provided that the at least one ball channel in a cross section normal to the longitudinal extension of the thread at least partially corresponds to an outer contour of the ball arranged in the at least one ball channel, possibly with the exception of a recess in the area of the thread base of the external thread and/or described below. or the internal thread.

It is preferably provided that the at least one external thread and/or the at least one internal thread has a recess in the region of the thread root, preferably which recess extends along the at least one internal thread and/or along the at least one external thread from a beginning of the at least one Ball channel extends to the end of at least one ball channel.

[0049] The at least one recess in the area of the thread root allows a contact surface between the balls and the internal thread and/or the external thread and

be broken, with a more favorable introduction of force and / or force distribution between the balls and the internal thread and / or the external thread can be implemented (two or more contact points instead of one contact point).

For example, a compressive force between the spindle and the at least one spindle nut can be introduced via the thread at a 45° angle, for example, if contact between the balls and the thread root is prevented by the at least one recess in the region of the thread root.

It can be provided that the recess has a variable cross-sectional area along the at least one ball channel, preferably which cross-sectional area is designed to oscillate along the at least one ball channel.

It can be provided that a lubricant, preferably lubricating oil, is guided through the recess through the internal thread and/or external thread in at least one ball channel.

By configuring the recess with a variable cross-sectional area along the longitudinal extent, a suction effect can be generated in the recess via the balls passing through the at least one ball channel, as a result of which a lubricant present in the recess, such as lubricating oil, can be conveyed along the recess.

Such a design is comparable to plain bearings with a non-cylindrical lubricating gap, hydrostatic plain bearings and/or hydrodynamic sliding bearings, the flow of the lubricant being controlled and/or promoted by the geometric design between the moving and the non-moving body of the gap can.

The cross-sectional area can preferably vary in depth.

It can preferably be provided that the at least one feed device has at least one delivery device, preferably a pump, for delivering and/or pressurizing the fluid.

It can be provided that the balls are spaced apart by a spacer device, preferably a ball cage or spacer.

By providing a spacer device, the balls can be prevented from rubbing against each other, whereby abrasion of the balls can be significantly reduced. This spacing can be provided by conventional ball cages or spacers from the field of ball bearings.

[0059] If the drive unit has several ball channels with balls arranged therein, a feeding device according to the invention can preferably be provided for each of the ball channels.

Protection is also sought for a plasticizing or shooting unit with at least one drive unit according to the invention.

Protection is also sought for a shaping machine with such a plasticizing or closing unit and/or at least one drive unit according to the invention.

[0062] Further advantages and details of the invention result from the figures and the associated description of the figures. while showing

1 shows a first exemplary embodiment of a drive unit according to the invention,

2 shows a detailed view of an exemplary embodiment of a drive unit according to the invention,

3 shows a further detailed view of an exemplary embodiment of a drive unit according to the invention,

4 shows a sectional view of an exemplary embodiment of a drive unit according to the invention,

Figure 5 shows a detailed view of Figure 4, and Figure 6 shows a shaping machine.

1 shows a first exemplary embodiment of a drive unit 1 according to the invention for a shaping machine 2. The drive unit 1 has a spindle 3 which is rotatably mounted about the longitudinal axis 7.

The spindle 3 is connected to the first component 33 of a shaping machine 2 in a motion-locked manner in the longitudinal direction relative to the longitudinal axis 7 and can be driven in rotation about the longitudinal axis 7 .

Furthermore, the drive unit 1 has a spindle nut 4, which (linearly as well as rotationally) is connected to the second component 34 of the shaping machine in a non-moving manner.

Of course, the spindle 3 could also be fixed in relation to the first component 33 and/or the spindle nut 4 could be rotationally connected to the second component 34 and be rotationally drivable relative to the second component 34 .

The spindle 3 has an external thread 5, which external thread 5 winds around the spindle 3 along the longitudinal axis 7 with a pitch.

The spindle nut 4 has an internal thread 6 , which internal thread 6 extends along the longitudinal axis 7 with the same pitch as the external thread 5 of the spindle 3 .

A ball channel 8 is formed between the external thread 5 and the internal thread 6 as a result of the interaction of the external thread 5 and the internal thread 6.

The ball channel 8 extends from a start 32 along the longitudinal extent of the external thread 5 of the spindle 3 and the internal thread 6 of the spindle nut 4 to the end 11 of the ball channel 8, with balls 9 are arranged for power and / or movement transmission between the spindle 3 and the spindle nut 4.

A rotational movement of the spindle 3 about the longitudinal axis 7 thus necessarily results in a linear movement of the spindle nut 4 along the longitudinal axis 7 via the ball channel 8 and the balls 9 arranged therein, with the dependence of the rotational movement of the spindle 3 on the linear movement of the spindle nut 4 is defined by the pitch of the external thread 5 and the internal thread 6.

A return device 12 is also provided. This return device 12 is designed to guide the balls 9 from the end 11 of the ball channel 8 between the spindle 3 and the spindle nut 4 to a beginning 32 of the ball channel 8 between the spindle 3 and the spindle nut 4 .

The balls 9 in the ball channel 8 and the return device 12 of this exemplary embodiment can be spaced apart from one another by a spacing device, in which case embodiments with ball cages or spacers can be used.

The first component 33 of FIG. 1 could be designed, for example, as a machine frame 24 and/or end plate 20, whereas the second component 34 could be designed as a movable mold clamping plate 21, with a rapid lifting device for a clamping unit 18 of a molding machine being connected via the drive unit 1 2 could be provided.

Of course, further intermediate components can also be arranged between the first component 33 and the second component 34 and the spindle 3 or the spindle nut 4, which transmit the corresponding movements and/or forces.

2 shows a detailed view of an embodiment of a drive unit 1 according to the invention in a cross section perpendicular to the longitudinal axis 7, the balls 9 of the drive unit 1 at the end 11 of a ball channel 8 being visible.

The balls 9 run on an external thread 5 of the spindle 3 in a ball channel 8.

The internal thread 6 of a corresponding spindle nut 4 forming the ball channel 8 with the external thread 5 is not shown in this representation in order to ensure a better overview.

The ball deflection device 13 is provided at the end 11 of the ball channel 8 .

This ball deflector 13 is designed to deflect the balls from the ball channel 8 into a return device 12, it being evident how the balls 9 can roll on the surface of the ball deflector 13.

This ball deflection 13 has a finger-shaped extension 15 extending in the direction of the center of the ball channel 8 .

Furthermore, a supply device 10 for fluid is provided in the area of the end 11 of the spherical channel 8 .

This feed device 10 is designed to flow a fluid onto the balls 9 in the region of the end 11 of the ball channel 8 , as a result of which the balls 9 can be lifted off the external thread 5 .

As can be seen, as a result of the fluid flowing against the balls 9, the balls 9 are lifted off the external thread 5 of the spindle 3 before they reach the ball deflection device 13, so that the balls 9 do not hit the ball deflection device 12, more precisely: the finger-shaped extension 15, hit suddenly, whereby the wear of the ball deflection 13 and the balls 9 can be reduced.

By preventing the balls 9 from "impacting" on the ball deflection device 13 and by the balls 9 gently resting on the surface of the ball deflection device 13, it is also no longer necessary to form the ball deflection device 13 with a material that is significantly less hard than the balls 9, since the balls 9 are no longer at risk of being damaged by the impact.

Thus, the ball deflection device 13, more precisely: the finger-shaped extension 15, can be made of a metallic material.

In certain embodiments, it can of course still be provided to use a ball deflection device 13 made of plastic.

The delivery device 10 of this exemplary embodiment has a fluid channel 14 .

This fluid channel 14 for flowing against the balls 9 is directed towards an area of the balls 9 facing the external thread 5 in order to lift the balls 9 off the external thread 5 .

The fluid channel 14 is arranged in the finger-shaped extension 15 and opens out at a finger end facing the center of the ball channel 8, whereby the fluid flows through the finger end (the tip of the finger) between the external thread 5 of the spindle 3 and the balls 9 into the Ball channel 8 can be introduced, whereby the balls 9 can be lifted from the spindle surface.

By providing the at least one fluid channel 14 in a finger-shaped extension 15 of the ball deflection device 13, a temperature-controlling, preferably cooling, effect of the fluid flowing through the fluid channel 14 can also be used to temperature-control the finger-shaped extension 15. preferably to cool.

3 shows a detailed view of an exemplary embodiment of a drive unit 1 according to the invention in a section along the longitudinal axis 7 of a spindle 3 and a spindle nut 4.

[0099] This FIG. 3 shows very clearly how the external thread 5 of the spindle 3 and the internal thread 6 of the spindle nut 4 have a curve due to the versions with the same pitch.

form gel channel 8, wherein the balls 9 are arranged.

The ball channel 8 at least partially has a cross-sectional geometry corresponding to the balls 9, seen in a cross section normal to the longitudinal extent of the external thread 5 and/or the internal thread 6.

The external thread 5 of the spindle 3 has, in the region of the thread root, a recess 16 which extends along the external thread 5 and which is formed from a beginning 32 of the ball channel 8 to an end 11 of the ball channel 8 .

With the help of this recess 16, the area in which the balls 9 roll is interrupted on the external thread 5, which is favorable for power transmission between the spindle 3 and the spindle nut 4.

A resultant force between the spindle 3 and the spindle nut 4 is always transmitted via the balls 9 at an angle of approximately 45°, resulting in optimal force introductions in terms of strength.

shows a detailed view of an embodiment of a drive unit 1 according to the invention in a cross section transverse to the longitudinal axis 7, a spindle 3 and a spindle nut 4, the section being selected parallel to the pitch of the internal thread 6 and the external thread 5.

This section shows the recess 16, as already shown in FIG. 3, along the thread root of the external thread 5 of the spindle 3.

FIG. 5 shows the detailed view X of the detail X marked in FIG. 4, wherein a variable cross-sectional shape of the recess 16 can be seen in the enlargement.

This variable cross-sectional shape of the recess 16 varies along the longitudinal extent of the recess 16 in an oscillating manner, with recurring, continuously transitioning cross-sectional shapes of the recess 16 occurring.

Due to this variable cross-sectional area of the recess 16, it can be implemented that a lubricant (e.g. lubricating oil) present in the recess 16 is conveyed via the recess 16 by the movement of the balls 9, whereby the continuous movement of the balls 9 in the external thread 5 of the spindle 3 creates a suction effect in the recess 16, the lubricant being promoted by this suction effect.

The molding machine 2 shown by way of example in FIG. 6 is an injection molding machine and has an injection unit 19 and a clamping unit 18 which are arranged together on a machine frame 24 . Alternatively, the machine frame 24 could also be designed in several parts.

The clamping unit 18 has a stationary mold mounting plate 25, a movable mold mounting plate 21 and a face plate 20.

The movable platen 21 can be moved relative to the machine frame 24 via a closing drive 22 shown symbolically. The closing drive 22 can be designed according to one of the previously described embodiments of a drive unit 1 .

The drive unit 1 according to the invention can be driven particularly preferably by means of an electric motor.

Mold halves of a mold 23 can be clamped or mounted on the fixed platen 25 and the movable platen 21 (shown in phantom).

The fixed mold mounting plate 25, the movable mold mounting plate 21 and the end plate 20 are supported and guided relative to one another by the bars 26.

The molding tool 23 shown closed in FIG. 6 has at least one cavity. An injection channel leads to the cavity, via which a plasticized mass of the plasticizing

gregates 17 can be supplied.

The injection unit 18 of this exemplary embodiment has an injection cylinder 27 and an injection screw arranged in the injection cylinder 27 . This injection screw can be rotated about its longitudinal axis and can be moved axially along the longitudinal axis in the conveying direction.

These movements are driven by a drive unit shown schematically. This drive unit preferably comprises a rotary drive for the rotary movement and a linear drive for the axial injection movement, it being possible for the drive for the axial injection movement to be implemented according to an exemplary embodiment of a drive unit 1 according to the invention.

6 shows a shaping machine 2 with an injection unit 19, the injection unit 18 shown in this exemplary embodiment having an injection screw, which is also used for plasticizing a material to be plasticized.

The injection screw is mounted in the injection cylinder 27 so that it can be displaced axially along a longitudinal axis.

The plasticizing unit 17 (and thus the injection unit 19) is connected to a control or regulating unit 28 in terms of signals. The control or regulating unit 28 outputs control commands, for example to the plasticizing unit 17 (for example to the linear drive 1 of the plasticizing unit 17 or the closing drive 22 of the closing unit 18).

The control or regulation unit 28 can be connected to an operating unit 30 and/or a display device 31 via a signal-conducting connection 29 or can be an integral part of such an operating unit 30 .

REFERENCE LIST:

1 drive unit

2 shaping machine

3 spindle

4 spindle nut

5 external threads

6 internal threads

7 longitudinal axis

8 ball channel

9 ball

10 feeding device

11 End of ball channel

12 return device

13 ball deflection

14 fluid channel

15 finger-shaped process

16 recess

17 plasticizing unit

18 locking unit

19 injection unit

20 face plate

21 moveable platen 22 closing drive

23 forming tool

24 machine frames

25 fixed platen 26 bar

27 injection cylinder

28 control or regulation unit 29 signal-conducting connection 30 operating unit

31 display device

32 beginning of the ball channel 33 first component

34 second component

Claims (14)

patent claims A drive unit (1) for a molding machine (2) comprising - a spindle (3) with at least one external thread (5), which at least one external thread (5) winds around the spindle (3) along a longitudinal axis (7) with a pitch, and - at least one spindle nut (4) with at least one internal thread (6), which at least one internal thread (6) extends along the longitudinal axis (7) with the same pitch as the at least one external thread (5) of the spindle (3), between the at least one external thread (5) and the at least one internal thread (6) there is at least one ball channel (8) with balls (9) arranged therein for the transmission of force and/or movement between the spindle (3) and the at least one spindle nut (4). , characterized in that at least one supply device (10) for a fluid is provided in the region of one end (11) of the at least one ball channel (8), whereby the balls (9) in the region of the end (11) of the at least one ball channel (8) to lift the balls (9) from the at least one external thread (5) through which the fluid can flow. 2. Drive unit according to claim 1, wherein at least one return device (12) is provided, which at least one return device (12) is designed to move the balls (9) from the end (11) of the at least one ball channel (8) between the spindle (3 ) and the at least one spindle nut (4) to a beginning (32) of the at least one ball channel (8) between the spindle (3) and the at least one spindle nut (4). 3. Drive unit according to one of the preceding claims, wherein at the end (11) of the at least one ball channel (8) a - preferably formed from a metallic material - ball deflection (13) is arranged, which ball deflection (13) is designed to the balls ( 9) from the at least one ball channel (8) into the at least one return device (12), preferably wherein the at least one feed device (10) is arranged in the ball deflection (13). 4. Drive unit according to at least one of the preceding claims, wherein the at least one feed device (12) has at least one fluid channel (14) for flowing against the balls (9). 5. Drive unit according to claim 4, wherein the at least one fluid channel (14) for flowing against the balls (9) onto the balls (9) - preferably onto a region of the balls (9) facing the at least one external thread (5) - is directed. 6. Drive unit according to at least one of claims 3 to 5, preferably 4 or 5, wherein the ball deflection device (13) has a finger-shaped extension (15) extending in the direction of a center of the at least one ball channel (8), preferably wherein the at least one fluid channel (14) is arranged in the finger-shaped extension (15) and opens out into the at least one ball channel (8) at a finger end facing the center of the at least one ball channel (8). 7. Drive unit according to at least one of the preceding claims, wherein the fluid is compressed air, lubricating oil and/or compressed air charged with lubricating oil. 8. Drive unit according to at least one of the preceding claims, wherein the at least one ball channel (8) in a cross section normal to the longitudinal extent of the thread (5, 6) corresponds at least partially to an outer contour of the balls (9) arranged in the at least one ball channel (8). 9. Drive unit according to at least one of the preceding claims, wherein the at least one external thread (5) and/or the at least one internal thread (6) has a recess (16) in the area of the thread root, preferably which recess (16) extends along the at least one Internal thread (6) and / or along the at least an external thread (5) from a beginning (32) of the at least one ball channel (8) to the end (11) of the at least one ball channel (8). 10. Drive unit according to claim 9, wherein the recess (16) along the at least one ball channel (8) has a variable cross-sectional area, preferably which cross-sectional area is designed to oscillate along the at least one ball channel (8). 11. Drive unit according to at least one of the preceding claims, wherein the at least one feed device (10) has at least one conveying device, preferably a pump, for conveying and/or for pressurizing the fluid. 12. Drive unit according to at least one of the preceding claims, wherein the balls (9) are spaced apart by a spacer device, preferably at least one ball cage or at least one spacer. 13. Plasticizing or closing unit with at least one drive unit (1) according to at least one of claims 1 to 12. 14. Shaping machine with at least one plasticizing (17) or closing unit (18) according to claim 13 and/or at least one drive unit (1) according to at least one of claims 1 to 12. 4 sheets of drawings