DE8906866U1 - Rolling unit - Google Patents

Description

- 5 -roller unit

The innovation relates to a rolling unit with a rolling tool and at least one rolling element that can be placed against a workpiece surface under rolling force and is rotatably mounted, as well as with hydraulically operated means for generating the rolling force and a device connected to the hydraulically operated means for generating the desired pressure and volume flow of a fluid that acts on the means for generating the rolling force.

Rolling units of the type described above are generally known and have proven themselves well in practical use. For example, they are generally used on center-cut machines for the burnishing of turned parts. Depending on requirements, such a tool is clamped onto the machine support by the operator and removed again after use. For supply purposes, such a known rolling unit has a hydraulic device in addition to the rolling tool, which is connected to the tool via pipes or hoses and has its own pump-motor unit to generate the necessary pressure, so that a rolling unit is created consisting of a rolling tool, a device for generating the necessary hydraulic pressure and a connecting means between this device and the tool. Such hydraulically actuated tools are therefore not suitable for use on machines on which an automatic or manually controlled tool change takes place during the machining of a workpiece.

The innovation is therefore based on the task of proposing a rolling unit of the type described above, which can remain in the tool turret or in the tool carrier of the associated machine tool as an installed tool or can be changed between a conventional tool turret or tool carrier and a tool magazine assigned to the machine and not, as was previously necessary with hydraulically operated known tools, installed separately for each machining of the workpiece and after completion of the machining

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has to be removed each time.

According to the innovation, this task is solved in a rolling unit of the type described at the beginning in that the rolling tool and the device for generating the desired pressure are designed as a structural unit and are rigidly connected to one another, with connections for supplying energy to the device mentioned being provided, which are connected or can be connected to corresponding connections for supplying energy to a machine tool. The external hydraulic station that was previously used as a device for generating the necessary or desired pressure is thus eliminated and becomes the tool's own device. In this way, the coolant circuit or lubricant circuit that is always present on such machine tools can be used for energy supply at the same time, which then simultaneously provides large volume flows for the tool if necessary, while the necessary high fluid pressure is generated by the device inside the tool for generating the desired pressure, so that this device can be kept correspondingly small, since it does not have to handle large volume flows. It is particularly advantageous if both the rolling tool and the device for generating the desired pressure each have an independent housing that is rigidly connected to one another. This makes it easier to adjust the performance of the tool and printing device and to replace worn components.

Such a device for generating the desired pressure can be formed from a simple gear pump or vane pump or piston pump, the latter of which can be driven by a cam or an eccentric disk, which can be driven by an associated drive of the machine tool used via its own drive shaft. Such drive devices are often present, for example, in conventional NC lathes or CNC lathes. However, it is also conceivable to provide a further hydraulic motor connected to the pump as the drive, which is also operated by the coolant circuit or lubricant circuit of the machine.

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which then not only supplies the hydraulic motor, but also provides the necessary volume flow for the pump driven by the hydraulic motor, which ensures the required pressure. At least when using a piston pump, it is sensible to connect a pressure accumulator between the tool and the piston pump in order to dampen the pressure surges of the piston pump.

The rolling unit can have a separate clamping shaft for clamping. The clamping shaft can preferably have standard dimensions, so that the entire rolling unit fits into the also standardized and usual receptacles of a tool magazine or a turret head of NC-controlled or CNC-controlled machine tools via such a clamping shaft with standardized dimensions. In this case, the necessary drive shaft for the pump can advantageously be rotatably mounted in this clamping shaft.

The entire rolling unit according to the innovation can be built particularly small if the roller head is designed as a hydrostatic bearing for the rolling element, which is connected to the pressure side of the associated pump via a connecting channel.

The innovation will now be described in more detail using the embodiments shown in the drawings.

Show it:

Figure 1 Rolling unit with hydrostatically mounted rolling element in section

Figure 2 Rolling unit with rolling element actuated by a piston-cylinder unit in section

Figure 3 Hydraulic circuit diagram

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Figure 4 Hydraulic circuit diagram

Figure 5 View in the direction of arrow X-X in Figure 2

Figure 6 Longitudinal section through a construction variant

Figure 7 Section I-I according to Figure 6

Figure 1 shows a rolling unit with a rolling tool 1 with a hydrostatically mounted rolling element 2, which is held and guided in the housing 1'. This rolling unit shown in Figure 1 is composed of the functional groups A to E, with the functional group A forming the rolling tool 1. The functional group B comprises a piston pump 3, which is accommodated in an associated pump housing 3', with this piston pump 3 acting with its pressure side λ on the pressure chamber 5 of the rolling tool 1. For this purpose, the housing Γ lies directly with a corresponding flat surface on an associated flat surface of the pump housing 3'. No pipes or hoses are required between the two functional groups.

The pressure chamber 5 of the rolling tool 1 also serves as a pressure accumulator 29, which in the embodiment is designed as a spring pressure accumulator. For this purpose, the interior of this spring pressure accumulator 29 (not further specified) has a piston 28 acted upon by the pressure medium, which is supported by a spring 5k on a cover ^5. The pressure behavior of the pressure accumulator is determined by the characteristic curve of the spring 5*. A seal 49, which can be designed as an O-ring, for example, can ensure the necessary tightness in the area of the pressure connection between the functional groups A and B. However, other types of seals are also possible here.

In the pump housing 3* of the piston pump 3, a drive shaft 6 is rotatably mounted in a manner known per se, on which an eccentric 19 is arranged in a rotationally fixed but axially immovable manner. A piston 23 rests on the peripheral surface of the eccentric 19, which is always in

of this system. A pump chamber 22 is connected to the cylinder 27 on the suction side of the piston pump 3 via a check valve 2k . In a reverse piston stroke, the suction side becomes the pressure side and thus closes the check valve 2k , but opens a check valve 26, whereby pressure oil is made available on the pressure side of the piston pump 3 to supply the pressure chamber 5 of the rolling tool 1. The structure of such a pump is generally known, so that it does not need to be discussed further here.

The drive shaft 6 of the piston pump 3 extends into the housing 52* of an intermediate piece 52 and is connected there via a coupling 7 to an output shaft 8 of a hydraulic motor 9, which is housed in an associated housing 9'. The intermediate piece 52 and the hydraulic motor 9 form the functional groups C and D. Both functional groups rest against each other via corresponding flat surfaces, with the functional group C resting with another corresponding flat surface on an associated flat surface of the piston pump 3 as functional group B. Surface seals 51 can ensure the necessary tightness.

The entire unit is completed by the functional group E, which forms the cover 10. The cover 10 essentially forms a housing 10', on which the clamping shaft 11' with preferably standardized dimensions is provided. The housing 10' also has an oil connection 12, which is led to the pump chamber 22 via a channel 21. Another channel 15, which is also connected to the oil connection 12, is led to the opening 16 of the hydraulic motor 9 and, if a fluid flow H is provided, drives it. Such hydraulic motors and the necessary guidance of the fluid flow are known, so that a more detailed description of the structure and function is omitted here.

The necessary hydraulic circuit diagram for the rolling unit shown in Figure 1 is shown in Figure 3. It should be noted that the necessary safety valve 30 for protecting the piston pump 3 in the

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Example of an embodiment according to Figure 1 is provided on the rolling tool. This simultaneously represents a sensible protection of the hydrostatically operating rolling tool, so that this tool can be protected independently of the pump. This safety valve 30 can then also take over the pump protection at the same time. However, a similar separate protection against overpressure can also be provided on the piston pump 3. In this case, of course, this pump protection can also take over the protection of the hydrostatic tool. It should also be pointed out that |( in Figure 3 the pressure accumulator 29 is designed as a so-called bladder accumulator.

was shown, while in the embodiment according to Figure i the pressure accumulator is a spring pressure accumulator. This is to indicate that of course different pressure accumulators can be used and the device is not limited to a specific pressure accumulator design.

The embodiment according to Figure 2 shows a roller head 44 constructed in the usual way, in contrast to the hydrostatic roller head 44', in which a rolling element 2 rests on a support roller 20 and is supported by it. The rolling element 2 is guided in a manner known per se by a cage 18.

The roller head 44 is attached to the free end of a piston rod 42, at the other end of which a piston 41 is arranged, which is arranged in a conventional and known manner so as to be displaceable in a cylinder chamber 40. On the side facing away from the piston rod 42, the cylinder chamber 40 is closed by a cover 45 with a seal 46, preferably designed as an O-ring. A locking ring 47 holds the cover 45 in its position. A throttle valve 61 is installed in the cover 45.

The piston 41 also has a seal 48 in the usual and known manner, with which the piston 41 is sealed against the wall of the cylinder chamber 40.

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On the piston rod side, a spring 43 is also provided in the cylinder chamber in the usual way, which uses its force to constantly move the piston 41 and thus retract the piston rod 42. An extension movement of the piston rod 42 with the necessary force is ensured by applying pressure to the part of the cylinder chamber 40 facing the piston rod, so that the side of the piston 41 that is free of the piston rod is pressurized with the appropriate pressure oil and thus moves the piston rod 42 with the roller head 44 in the direction of the workpiece 13. The tool in the embodiment according to Figure 2 is thus able to bridge a larger gap between the workpiece and the tool than the tool in the embodiment according to Figure 1. |>

&Idigr; The rolling tool 1 in the embodiment according to Figure 2, which there has the fs

Functional group F is followed by functional group G in the form of a gear pump 34 with pump housing 34'. If such a gear pump 34 is used, the throttle valve can be completely closed or omitted. The pump housing 34' is then followed by the housing 59 of the cover 10", whereby this housing 59 also has the clamping shaft 11 for a tool holder 57. The tool holder 57 is the machine tool |

assigned to which the tool is used. g

i The drive shaft 32 for the gears f is rotatable in the clamping shaft 11

39 and 39' stored in warehouses 38 and 38'. The necessary !*!

Tightness between the functional groups is restored by '-■

the flat seals 51 and, if necessary, by sealing rings 49. In the housing 59, an oil connection 35 leading to the outside is also provided, to which the corresponding supply line of the associated || machine tool is connected. A channel 36 leads the <j fluid flow 14 via the channel 37 to the gear pump 34, which ensures the necessary pressure of the fluid flow 14 and leads the fluid flow under pressure on the pressure side 4 into the cylinder chamber 40 of the ,; rolling tool 1. A safety valve 30 is led outwards from the pressure side 4 and protects the gear pump 34 against overload. The course of the channels 35, 36 and 37 as well as 4 is shown in Figure 5. "'"

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To drive the variant according to Figure 2, the drive shaft 32 can be connected to a drive shaft 60 of an electric motor 58 via the coupling 33. This electric motor 58 is already present in the associated machine tool as a drive device. The same applies to the drive shaft 60. Such known CNC-controlled machines usually have not only a drive for the main spindle but also additional spindles derived from the drive of the main spindle or driven separately, with which appropriate tools, such as a tool according to Figure 2 _, can be driven if required.

The hydraulic circuit diagram of the embodiment according to Figure 2 is shown in Figure *.

For both embodiments, the clamping shaft 11 or IV can correspond in its dimensions to DIN 69880, for example. When used on a machine tool, the clamping shaft 11 or 11' is brought into operative connection with the tool holder 57 of a machine tool and is firmly clamped. In the case of the embodiment according to Figure 1, the oil connection 12 is simultaneously tightly connected to the lubricant circuit of this machine when the tool is clamped in a tool carrier or in a tool holder 57. For this purpose, connections of a lubricant circuit that can be used can already be present in the area of the tool holder of such a machine in a known manner.

If the rolling tool 1 is now to carry out rolling processing on a rotating workpiece 13, the rolling tool 1 is brought into the working position in the tool holder 57 via the machine control system and the rolling element 2 is positioned in relation to the workpiece 13 in such a way that there is loose contact between the rolling element 2 and the workpiece 13, but no significant forces occur between the rolling element 2 and the workpiece 13. The lubricant circuit of the machine tool is then activated and a fluid flow 14 flows through the oil connection 12 into the channel 15 of the hydraulic motor 9. The

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Fluid flow 14 enters the gear housing 9' through the opening 16 and acts on the gears 17 and 17', which then convert the flow energy of the fluid flow 14 into rotational energy. The shaft 8 of the gear 17 then drives the drive shaft 6 of the piston pump 3, which has the eccentric 19, via the coupling 7. The fluid flow 14 flowing in through the oil connection 12 flows through the channel 15 and the channel 21 into the pump chamber 22, which then contains the eccentric 19 and the piston 23. The fluid flow 1* thus reaches the check valve 24 or suction valve of the piston pump 3. If the drive shaft 6 of the piston pump 3 is driven by the hydraulic motor 9 , the valve ₅ moves back and forth on the piston 23 under the spring pressure of the spring 25 on the eccentric 19, held in the cylinder 27. During the suction stroke of the piston 23, the suction valve 24 opens and fluid is sucked in. During the pressure stroke of the piston 23, the suction valve 2h closes and the pressure valve 26 opens and releases the pump outlet 4. Both valves, suction valve 24 and pressure valve 26, can be designed in their simplest form as conventional check valves. The fluid now enters the pressure chamber 5 of the rolling tool 1. The fluid, now translated to a much higher pressure than from the lubricant circuit of the machine tool, acts on the hydrostatically mounted rolling element 2 and generates the desired rolling force. The rolling element 2 is applied to the workpiece 13 under rolling force. When the fluid flows into the pressure chamber 5 of the rolling tool 1, the piston 28 of the pressure accumulator 29 is displaced against the spring force of the spring 54 and thus stores the fluid under pressure in order to compensate for pressure irregularities resulting from the design of the piston pump. If a gear pump is used instead of the piston pump, the pressure accumulator could be omitted. As already described, the spring 54, which resiliently supports the piston 28, is in turn supported on the free side by the cover 45, which, as also already described, is held in the housing by the locking ring 47. The entire structural unit shown in Figure 1 can be held together rigidly in the form of through-bolts designed as tie rods and only indicated by lines 50, 50'. All functional groups A to E are thus pressed tightly and closely together and form a rigid, solid block that is quite small.

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In the embodiment according to Figure 2, the pump drive is connected to a standard tool drive of the associated machine tool. The tool drive of the machine tool is shown in Figure 2 by the drive shaft 60 and the electric motor 58. Here too, the oil connection 35 is simultaneously connected to the lubricant circuit of the associated machine tool when the entire unit is clamped in the tool holder. In order to machine the workpiece 13, the rolling tool is in the tool carrier

or held in the tool holder 57 and brought into the working position controlled by the machine control system, so that the rolling element 2 is a small distance from the surface of the workpiece 13 to be machined. The lubricant circuit of the machine tool is then activated and a fluid flow 14 flows through the oil connection 35 into the channel 36 of the gear pump 34 and enters the channel 37, which is formed by the interior of the pump housing 34'. The inflowing fluid is brought to a pressure suitable for operating the rolling tool 1 by the gear wheels 39, 39' driven by the drive shaft 32 and flows through the pressure side 4 into the cylinder chamber 40, whereby the piston 41 with the piston rod 42 is displaced against the spring force of the spring 43. As a result, the rolling element 2, which is carried by the roller head 44, is pressed against the rotating workpiece 13, whereby the required rolling force is built up. The vent hole 53 ensures that no undesirable counterpressure is created in the installation space 55 for the spring 43.

The use of a gear pump in a unit design according to Figure 2 makes it possible to dispense with a pressure accumulator. The use of such a gear pump is not, however, mandatory. A piston pump could also be used. In this case, the throttle valve must be opened slightly so that, when the piston pump is at a standstill, the pressure in the cylinder chamber 40 can be reduced, which, when a gear pump is used, occurs via the leakage of the gear pump. If the throttle is opened further, it can serve as a pressure control unit in conjunction with the pump speed.

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because the flow rate through the throttle depends to a large extent on the pressure drop at the throttle. For example, with a piston pump, the full pump pressure is generated when the throttle is closed, even at low speed. If the throttle is now opened, the pressure drops, depending on the opening cross-section. It can then be increased again by increasing the pump speed.

Figure 6 now shows an embodiment in longitudinal section, in which the rolling tool 1 is connected to a receiving shaft 62, which is designed for a mounting in the work spindle or main spindle of a machine tool, for example a milling machine. The ^receiving shaft 62 can be designed in the usual way. On the end of the receiving shaft 62 facing away from the machine spindle 71, an intermediate region 64 is provided between the rolling tool 1 and the said end of the receiving shaft 62 and is firmly connected to the receiving shaft 62, which rotates with the receiving shaft and has a piston pump 65. For this purpose, a radial bore 72 can simply be provided in the said intermediate region 64, for example, into which a piston 73 is inserted. The piston 73 is under the preload of a spring 74, which is supported on the one hand on the said intermediate region 64 and on the other hand on a collar 75 of the piston 73. ,

The radial bore 72 is connected on the suction side via a check valve 76 to a supply line 78, via which the necessary fluid is supplied, for example, from the circuit of the machine tool.

On the pressure side, as is usual with piston pumps, a further check valve 77 is provided through which the pressure oil is supplied to the rolling tool 1, which in the illustrated embodiment according to Figure 6 is designed as a roller head with a hydrostatically mounted roller % . The pressure line 79 leading to the roller head is connected via a connecting line 80 to a pressure accumulator 70, which is also arranged in the intermediate region 64 and therefore rotates together with the rolling tool 1 and the machine spindle 71. The pressure accumulator 70 can be designed as a spring pressure accumulator, g

as already described in Figure 1. fe,

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The intermediate area 64 is surrounded over part of its length or width by a ring 67 which is rotatably mounted in this intermediate area 64, for example via roller bearings 81. Collars 82 and 83 ensure axial immovability. The ring 67 has an inner curved track 68 on its inside, against which the actuating cam 66 of the piston 73 rests and is held in place by the spring 74. On its outside, the ring 67 has a so-called torque support 69 which is supported on any holding part 84 of the machine tool 63. If the machine spindle 71 is now set in rotation, the entire structure described, with the exception of the ring 67, rotates with it. As a result, the actuating cam 66 of the piston 73 of the piston pump 65 runs along the inner curved path 68 of the ring 67 and is thereby set into a radial oscillating movement, i.e. into the necessary pumping movement. The necessary fluid is supplied through the supply line 78 and brought to the necessary pressure for the rolling tool 1 by the piston pump 65. The pressure fluctuations that always occur with a piston pump are absorbed by the pressure accumulator 70. The rolling tool 1 can now be guided with its rolling element 2, for example, against the flat surface 85 of an unspecified workpiece and carry out a smooth rolling process there. The rolling element 2 describes a circle on the flat surface 85 due to its eccentric position to the axis of rotation 86. A linear feed movement of the tool in the direction of arrow 87 by corresponding displacement of the machine spindle 71 ensures that these circles are superimposed, so that with such a tool a flat surface of a workpiece can be rolled smooth, path by path.

In the present embodiment according to Figure 6, it is entirely possible not to guide the supply line 78 centrally through the machine spindle 71 and the receiving shaft 62, but instead to connect it externally to the torque support 69, which is then correspondingly hollow and is guided back to the pump 65 via a line 88 shown in dash-dotted lines through a gap 89.

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The subject of the innovation is the first time that a rolling unit has been designed in such a way that hydraulic actuation of the tool is possible, while at the same time the entire unit can be kept so small that it can be used as a tool on machine tools, such as CNC-controlled automatic lathes, and can be held there in the usual tool holders or tool magazines. A connection to any separate additional units external to the machine is no longer necessary.

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List of reference symbols used

1 rolling tool &Ggr; Housing 2 Rolling element 3 Piston pump 3' Pump housing * Print page 5 Printing room 6 drive shaft 7 coupling G Output shaft 9 Hydraulic motor 9' Housing 10 cover 10' Housing 10" cover 11 Clamping shaft 11' Enspannschaft 12 Oil connection 13 workpiece 1* Fluid5trom 15 channel 16 opening 17 gear 17' gear 18 Cage 19 eccentric 20 Support roller 21 channel 22 Pump room

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23 pistons

24 Check valve

25 Spring

26 Check valve

27 cylinders

28 pistons

29 Pressure accumulator

30 Safety valve

31 unused

}2 drive shaft

33 Clutch

34 Gear pump 34' Pump housing

35 oil connection

36 Channel

37 Channel

38 camps 38' camps

39 Gear 39 ¹ Gear

40 Cylinder chamber

41 pistons

42 Piston rod

43 Spring

44 roller head 44' roller head

45 lids

46 Seal

47 Retaining ring

48 Seal

49 Seal

50 Line 50" Line

51 Flat gasket

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Intermediate piece - 20 - &bull; t ··*· < %m ·· * &lgr;*
t I · ■ Housing &bull; * ··· * &bull; 1 · · Vent hole 52 Feather 52' Installation space 53 unused 5* Tool holder 55 Electric motor 56 Housing 57 Abbot fever wave 58 throttle valve'. 59 On nourishment 60 Machine tool 61 Intermediate area 62 Piston pump 63 64 65

66 actuating cams

67 Rings

68 inner curve track

69 Torque support

70 pressure accumulators

71 Machine spindle

72 Radial bore

73 pistons
7k spring

75 collar

76 Check valve

77 Check valve

78 Supply line

79 Pressure line

80 connecting cable

81 rolling bearings

82 collar

83 Collar

84 Holding part

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85 Plane area

86 Rotation axis

87 Arrow

88 Line

89 Space

Claims (1)

1. Rolling unit with a rolling tool with at least one rolling element that can be placed against a workpiece surface under rolling force and is rotatably mounted, as well as with hydraulically operated means for generating the rolling force and a device connected to the hydraulically operated means for generating the desired pressure and volume flow of a fluid acting on the means for generating the rolling force, characterized in that the rolling tool (1) and the device (B-E; G, H) for generating the desired pressure are designed as a structural unit and are rigidly connected to one another, with connections being provided for supplying energy to the said device, Il «Ml ·· ·· t · ·· which are or can be connected to corresponding connections for supplying energy to a machine tool. 2. Rolling unit according to claim 1, characterized in that the rolling tool (1) and the device (B-E; G, H) for generating the desired pressure each have an independent housing (l'j 3', 52', 9', 10'; 34', 59) which are rigidly connected to one another. 3. Rolling unit according to one of claims 1 and 2, characterized in that the device for generating the desired pressure is designed as a pump (3, 34) and is connected or can be connected on the suction side to the lubricant circuit or coolant circuit of the machine on which the unit is used. 4. Rolling unit according to one of claims 1 to 3, characterized in that the pump (3,34) is connected or connectable to a drive motor (9,58). 5. Rolling unit according to claim 4, characterized in that the pump (3,34) for connection to the drive motor (9,58) has a drive shaft (6,32) which can be connected or is connected to a corresponding output shaft (8,60) of the drive motor. 6. rolling unit according to claim 3, characterized in that the drive motor is designed as a hydraulic motor (9) and is connected or can be connected to the coolant circuit or lubricant circuit of the machine on which the unit is used for the energy supply. 7. Rolling unit according to one of claims 1 to 6, characterized in that the device for generating the desired pressure comprises a hydraulic pump (3) and a hydraulic motor (9), the pump and motor being arranged in a common housing (B, C, D) or in separate but rigidly connected housings (3', 52', 9 ¹ ). f* · &diams; * 4 ft ·· f &PSgr; · · 8. Rolling unit according to claim 7, characterized in that the device further comprises a pressure accumulator (29). 9. Rolling unit according to one of claims 1 to 8, characterized in that the rolling unit is divided into functional groups (AH), each functional group having its own housing (U', ^3' , 52', 9', 10', 34', 59) with at least one flat contact surface and wherein, to produce the rolling unit, all housings of the intended functional groups (AE; FH) are placed one next to the other in a functionally correct manner via the flat contact surfaces and are rigidly connected to one another. 10. Rolling unit according to one of claims 1 to 9, characterized in that the pump (3) is designed as a piston pump. 11. Rolling unit according to claim 10, characterized in that the piston (23) of the piston pump (3) is moved by means of a rotatingly driven or drivable cam or eccentric (19). 12. Rolling unit according to claim 5, characterized in that the drive motor (58) is an electric motor. &igr; ^ «vf_i :_i &igr;&lgr;. t_ _ : -&igr; A .·&iacgr;_ I &igr; l-: &mdash; r» -l_ -1..--L. &igr; J. nai^ciiiiicii iim~ii a ucr &pgr;&igr;&igr;&ogr;&mgr;&igr; u<_iic &igr; uis 7, uouuiui net that the pump (34) is a gear pump. l*f. Rolling unit according to one of claims 1 to 13, characterized in that the rolling unit has a clamping shaft (11, H ¹ ) for receiving in a tool magazine, a turret head or in another tool holder (57) of the machine on which the unit is used. 15. Rolling unit according to claim 14, characterized in that the drive shaft (32) for the pump (34) is rotatably mounted in the clamping shaft (11) and can be coupled to a drive shaft of the machine via a coupling (33). &bull; * I t I t Il ·· »I *· III lit I # t I I ···· t I J I · II» I I · ··· Ii «al »III «&bull;It« · · · · · · ti 16. Rolling unit according to claim 8, characterized in that the pressure accumulator (29) is a spring pressure accumulator. 17. Rolling unit according to one of claims 1 to 16, characterized in that each rolling element (2) is guided, supported and rotatably mounted in a roller head (44'), the roller head (44 ¹ ) being designed as a hydrostatic bearing for the rolling element (2) and being connected or connectable to the pressure side (4) of the pump (3) by means of a connecting channel. 18. Rolling unit according to one of claims 1 to 17, characterized in that each rolling element (2) is guided, supported and rotatably mounted in a roller head (44), the roller head (44) being arranged at the free end of a piston rod (42) of a piston-cylinder unit (41, 42, 45, ), the cylinder chamber (40) of which is connected or connectable to the pressure side (4) of the pump (34) on the side of the piston (41) facing away from the piston rod (42). 19. Rolling unit according to claim 1, characterized in that the rolling tool (1) is connected to a receiving shaft (62) for a work spindle of a machine tool (63), wherein in the intermediate area (64) between the tool (1) and the receiving shaft (62) at least one piston pump \65/ with a locking ring \66/ is provided, which is connected on the pressure side to the hydraulically actuated means for generating the rolling force and on the suction side to fluid supply means, wherein the intermediate area (64) with the actuating cam (66) is surrounded by a ring (67) rotatably mounted on this intermediate area (64) with an inner curved track (68) for actuating the actuating cam (66) and wherein the ring (67) is prevented from unintentionally rotating by means of a torque support (69). 20. Rolling unit according to claim 19, characterized in that a pressure accumulator (70) is provided which rotates with the rolling tool (1) and is connected to the pressure side of the pump (65).