EP0353427B1 - Burnishing unit - Google Patents

Description

The invention relates to a rolling unit with a rolling tool and at least one rolling element which can be placed and rotatably supported against a workpiece surface under rolling force, and with hydraulically actuated means for generating the rolling force and a device connected to the hydraulically actuated means for generating the desired pressure and volume flow of the means for generating the fluid acting on the rolling force.

Rolling units of the type described above are generally known and have proven themselves well in practical use. You will e.g. generally used on tip lathes for the smooth rolling of turned parts. Depending on requirements, such a tool is manually clamped on the machine support by the operator and removed again after use. To supply such a known rolling unit in addition to the rolling tool also has a hydraulic device which is connected to the tool via pipes or hoses and has its own pump-motor unit for generating the necessary pressure, so that a rolling unit is formed from a rolling tool, device for Generation of the necessary hydraulic pressure and connecting means between this device and the tool. Such hydraulically loaded tools are therefore not suitable for use on machines in which an automatic or manually controlled tool change takes place during the machining of a workpiece.

With the SU 1303 383 A, a rolling unit of the type described above has also become known. In this rolling unit, two rolling devices are provided, which are mounted on a separate bed slide. For these rolling machines there is a separate one that is outside the machine

Hydraulic device provided with control means and means for generating the necessary pressure. Such a rolling unit thus also has the above-described defects.

The invention is therefore based on the object of proposing a rolling unit of the type described at the outset, which can remain in the tool turret or in the tool carrier of the associated machine tool as an installed tool or can be switched between a conventional tool turret or tool carrier and a tool magazine assigned to the machine and not, as in the case of hydraulically operated known tools previously necessary, must be installed separately for each machining of the workpiece and must be dismantled each time the machining is completed.

According to the invention, this object is achieved in a rolling unit of the type described in the introduction in that the rolling tool and the device for generating the desired pressure are constructed as a structural unit and are rigidly connected to one another, the device for generating the desired pressure being designed as a pump and on the suction side for energy supply to the mentioned device to the lubricant circuit or coolant circuit of the machine tool on which the unit is used, connected or can be connected. The previously common external hydraulic station as a device for generating the necessary or desired pressure is thereby eliminated and becomes the tool's own device. In this way, the coolant circuit or lubricant circuit that is always present in such machine tools can be used at the same time for energy supply, which then simultaneously provides, if necessary, large volume flows for the tool, while the necessary high fluid pressure is generated by the in-tool device for generating the desired pressure is generated so that this device can be kept correspondingly small can, since it does not have to deal with larger volume flows. It is particularly advantageous here if both the rolling tool and the device for generating the desired pressure each have an independent housing which is rigidly connected to one another. This makes it easier to adjust the power of the tool and the printing device, and to replace worn components more easily.

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 via a cam or an eccentric disc, 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, which is also operated by the coolant circuit or lubricant circuit of the machine, which then not only supplies the hydraulic motor but also the volume flow required for the pump driven by the hydraulic motor, which provides the necessary pressure. At least when using a piston pump, it makes sense to connect a pressure accumulator between the tool and the piston pump in order to dampen the pressure surges of the piston pump.

The roller unit can have a separate clamping shaft for clamping. The clamping shank can preferably have standard dimensions, so that the entire rolling unit has such a clamping shank with standardized dimensions in the likewise standardized and customary receptacles of a tool magazine or a turret head from NC-controlled or CNC-controlled machine tools. 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 invention can be made 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 with a connecting channel.

The invention will now be described with reference to the embodiments shown in the drawings.

• Figur 1 Walzeinheit mit hydrostatisch gelagertem Walzelement im Schnitt
• Figur 2 Walzeinheit mit von einer Kolben-Zylinder-Einheit betätigtem Walzelement im Schnitt
• Figur 3 Hydraulikschaltplan
• Figur 4 Hydraulikschaltplan
• Figur 5 Ansicht in Richtung des Pfeiles X-X aus Figur 2
• Figur 6 Längsschnitt durch eine Bauvariante
• Figur 7 Schnitt I-I nach Figur 6

Show it:

• Figure 1 rolling unit with hydrostatically mounted rolling element in section
• Figure 2 Rolling unit with the rolling element actuated by a piston-cylinder unit in section
• Figure 3 Hydraulic circuit diagram
• Figure 4 Hydraulic circuit diagram
• FIG. 5 view in the direction of arrow XX from FIG. 2
• Figure 6 longitudinal section through a construction variant
• FIG. 7 section II according to FIG. 6

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 FIG. 1 is composed of the functional groups A to E, the functional group A forming the rolling tool 1. The function group B comprises a piston pump 3, which is accommodated in an associated pump housing 3 ', this piston pump 3 acting on the pressure chamber 5 of the rolling tool 1 with its pressure side 4. For this purpose, the housing 1 'lies directly with a corresponding flat surface on an assigned 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 is designed as a spring pressure accumulator in the exemplary embodiment. For this purpose, the interior of this spring pressure accumulator 29, not designated in any more detail, has a piston 28 which is acted upon by the pressure medium and which is supported on a cover 45 via a spring 54. The pressure behavior of the pressure accumulator is determined here by the characteristic curve of the spring 54. A seal 49, e.g. can be designed as an O-ring, 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 a cam 19 is arranged in a rotationally fixed but axially immovable manner. On the circumferential surface of the eccentric 19 is a piston 23, which is always in by a spring 25 this facility is held. A pump chamber 22 is connected to the cylinder 27 on the suction side of the piston pump 3 via a check valve 24. In a reverse piston stroke, the suction side becomes the pressure side and thus blocks the check valve 24, but opens a check valve 26, whereby pressure oil is provided 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 there is no need to go into further detail here.

The drive shaft 6 of the piston pump 3 projects 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 lie against one another via corresponding flat surfaces, the functional group C with a further corresponding flat surface being in contact with an assigned flat surface of the piston pump 3 as the functional group B. Flat 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' is provided with preferably standardized dimensions. Furthermore, the housing 10 'has an oil connection 12 which is guided via a channel 21 to the pump chamber 22. Another channel 15, which is also connected to the oil connection 12, is guided to the opening 16 of the hydraulic motor 9 and, if a fluid stream 14 is provided accordingly, ensures its drive. Such hydraulic motors and the necessary guidance of the fluid flow are known, so that here too a detailed description of the structure and the mode of operation can be dispensed with.

The necessary hydraulic circuit diagram for the rolling unit shown in FIG. 1 is shown in FIG. 3. It should be noted that the necessary safety valve 30 for protecting the piston pump 3 in the Embodiment of Figure 1 is provided on the rolling tool. At the same time, this represents a sensible safeguard for the hydrostatically operating rolling tool, so that this tool can be safeguarded independently of the pump. This safety valve 30 can then simultaneously take over the pump protection. However, a similar separate protection against overpressure can also be provided on the piston pump 3. Conversely, this pump protection can of course also take over the protection of the hydrostatic tool. It should also be pointed out that the pressure accumulator 29 in FIG. Bladder accumulator was shown schematically, while in the embodiment of Figure 1, the pressure accumulator is a spring pressure accumulator. This is intended to indicate that, of course, different pressure reservoirs can be used and that the device is not restricted to a specific type of pressure reservoir.

The embodiment according to FIG. 2 shows a roller head 44 which is 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 the latter. 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 displaceably in a cylinder space 40 in the usual and known manner. On the side facing away from the piston rod 42, the cylinder chamber 40 is closed by a cover 45 with a seal 46, which is 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 space 40.

On the piston rod side, a spring 43 is also provided in the cylinder chamber in the usual way, which force constantly moves the piston 41 and thus wants to retract the piston rod 42. An extension movement of the piston rod 42 with the necessary force is ensured by pressurizing the part of the cylinder chamber 40 facing away from the piston rod, so that the piston rod-free side of the piston 41 is pressurized with corresponding pressure oil and thus the piston rod 42 with the roller head 44 in the direction of the workpiece 13 moves. The tool in the embodiment according to FIG. 2 is thus able to bridge a larger space between the workpiece and the tool than the tool in the embodiment according to FIG. 1.

The rolling tool 1 in the embodiment according to FIG. 2, which represents the functional group F there, is in turn followed by the functional group G in the form of a gear pump 34 with the pump housing 34 '. If such a gear pump 34 is used, the throttle valve can be completely closed or can be omitted. The pump housing 34 'now connects again to the housing 59 of the cover 10˝, this housing 59 also having the clamping shaft 11 for a tool holder 57. The tool holder 57 is assigned to the machine tool on which the tool is used.
In the clamping shaft 11, the drive shaft 32 for the gears 39 and 39 'is rotatably mounted in the bearings 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 there is also an outwardly directed oil connection 35 to which the corresponding supply line of the associated machine tool is connected. A channel 36 feeds the 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 pressurized fluid flow on the pressure side 4 into the cylinder space 40 of the rolling tool 1. A safety valve 30 is guided to the outside from the pressure side 4 and secures the gear pump 34 against overload. The course of the channels 35, 36 and 37 and 4 is shown in Figure 5.

For driving the construction variant according to FIG. 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 as a drive device in the associated machine tool. The same applies to the drive shaft 60. Such known CNC-controlled machines usually not only have a drive for the main spindle but also further spindles derived from or separately driven by the drive of the main spindle, with which, if necessary, appropriately used tools, such as a tool according to the figure 2, can be driven.

The hydraulic circuit diagram of the embodiment according to FIG. 2 is shown in FIG. 4.

For both embodiments, the clamping shaft 11 or 11 'in its dimensions e.g. comply with DIN 69880. When working 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 firmly clamped. In the case of the embodiment according to FIG. 1, the oil connection 12 is also tightly connected to the lubricant circuit of this machine when the tool is clamped in a tool holder or in a tool holder 57. For this purpose, connections of a lubricant circuit, which 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 be rolled on a rotating workpiece 13, then the rolling tool 1 is brought into the working position in the tool holder 57, controlled by the machine control, and the rolling element 2 is positioned in relation to the workpiece 13 such that there is loose contact between the rolling element 2 and the workpiece 13 is present, but no significant forces occur between the rolling element 2 and 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 Fluid stream 14 enters through the opening 16 in the gear housing 9 'and acts on the gears 17 and 17', which then convert the flow energy of the fluid stream 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 clutch 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 envelops the eccentric 19 and the piston 23. The fluid flow 14 thus reaches the check valve 24 or the 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 piston 23 moves back and forth under 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 24 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 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 rests against 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 whole assembly shown in Figure 1 can be rigidly held together in the form of trained as a tie rod and only indicated by lines 50, 50 ', through screws. All function groups A to E are pressed tightly and tightly against one another and form a rigid, solid block that is quite small.

In the embodiment according to FIG. 2, the pump drive is connected to a conventional tool drive of the assigned machine tool. The tool drive of the machine tool is shown in FIG. 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 carry out machining of the workpiece 13, the rolling tool is held in the tool carrier or in the tool holder 57 and brought into the working position controlled by the machine control so that the rolling element 2 is at a short distance from the surface of the workpiece 13 to be machined. The lubricant circuit of the machine tool is then activated and a fluid stream 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 '. Through the drive shaft 32 driven gears 39, 39 ', the inflowing fluid is brought to a pressure suitable for operating the rolling tool 1 and flows through the pressure side 4 into the cylinder chamber 40, whereby the piston 41 with the piston rod 42 against the spring force of the Spring 43 is moved. As a result, the rolling element 2, which is carried by the roller head 44, is pressed against the rotating workpiece 13, as a result of which the required rolling force is built up. The vent hole 53 ensures that there is no undesirable back pressure in the installation space 55 for the spring 43.

The use of a gear pump in the construction of the unit according to FIG. 2 makes it possible to dispense with a pressure accumulator there. However, the use of such a gear pump is not mandatory. A piston pump could also be used. In this case, the throttle valve must be opened slightly so that a pressure reduction can take place in the cylinder chamber 40 when the piston pump is at a standstill, which occurs when a gear pump is used via the leakage of the gear pump. If the throttle is opened further, this can serve as a pressure control unit in cooperation with the pump speed. since the throughput through the throttle is largely dependent on the pressure drop across the throttle. With a piston pump, for example, the full pump pressure is created 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 now be increased again by increasing the pump speed.

FIG. 6 now shows an exemplary embodiment in longitudinal section, in which the rolling tool 1 is connected to a holding shaft 62, which is designed for holding in the work spindle or main spindle of a machine tool, for example a milling machine. The receiving shaft 62 can be designed in a conventional manner. On the end of the holding shaft 62 facing away from the machine spindle 71, an intermediate region 64 is provided between the rolling tool 1 and said end of the holding shaft 62 and is fixedly connected to the holding shaft 62, which rotates with the holding shaft and which has a piston pump 65. For this purpose, a radial bore 72, in which a piston 73 is inserted, can simply be provided in the intermediate region 64 mentioned. The piston 73 is preloaded by a spring 74, which is supported on the one hand at the intermediate region 64 mentioned 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 exemplary embodiment shown in FIG. 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, as has already been described for FIG. 1.

The intermediate area 64 is covered over part of its longitudinal extent 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 on its inside an inner cam track 68, against which the actuating cam 66 of the piston 73 abuts and is held in contact by the spring 74. On the outside of 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 rotated, the entire structure described, with the exception of the ring 67, also rotates. As a result, the actuating cam 66 of the piston 73 of the piston pump 65 runs along the inner cam track 68 of the ring 67 and is thereby set into a radial oscillating movement, that is to say 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 a workpiece, which is not described in more detail, and can perform smooth rolling machining there. Due to its eccentric position to the axis of rotation 86, the rolling element 2 describes a circle on the flat surface 85. A linear feed movement of the tool in the direction of arrow 87 by a corresponding displacement of the machine spindle 71 ensures that these circles are superimposed, so that a flat surface of a workpiece can be rolled smooth path by path with such a tool.

In the present exemplary embodiment according to FIG. 6, it is entirely possible not to lead 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 which is shown by a line 88 shown in broken lines is passed through an intermediate space 89 back to the pump 65.

With the object of the invention it has been possible for the first time to design a rolling unit such that hydraulic actuation of the tool is possible, the entire unit being kept small enough 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 with any separate non-machine additional units is no longer required.

List of the reference symbols used

1

Rolling tool

1'

casing

2nd

Rolling element

3rd

Piston pump

3 ′

Pump housing

4th

Printed page

5

Pressure room

6

drive shaft

7

clutch

8th

Output shaft

9

Hydraulic motor

9 ′

casing

10th

cover

10 ′

casing

10˝

cover

11

Fixture

11 ′

Relaxation

12

Oil connection

13

workpiece

14

Fluid flow

15

channel

16

opening

17th

gear

17 ′

gear

18th

Cage

19th

eccentric

20th

Support roller

21

channel

22

Pump room

23

piston

24th

check valve

25th

feather

26

check valve

27th

cylinder

28

piston

29

Pressure accumulator

30th

Safety valve

31

unused

32

drive shaft

33

clutch

34

Gear pump

34 ′

Pump housing

35

Oil connection

36

channel

37

channel

38

warehouse

38 ′

warehouse

39

gear

39 ′

gear

40

Cylinder space

41

piston

42

Piston rod

43

feather

44

Roller head

44 ′

Roller head

45

cover

46

poetry

47

Circlip

48

poetry

49

poetry

50

line

50 ′

line

51

Flat gasket

52

Spacer

52 ′

casing

53

Vent hole

54

feather

55

Installation space

56

unused

57

Tool holder

58

Electric motor

59

casing

60

Output shaft

61

Throttle valve

62

Receiving shaft

63

Machine tool

64

Intermediate area

65

Piston pump

66

Actuating cams

67

ring

68

inner cam track

69

Torque arm

70

Pressure accumulator

71

Machine spindle

72

Radial bore

73

piston

74

feather

75

collar

76

check valve

77

check valve

78

supply line

79

Pressure line

80

Connecting line

81

roller bearing

82

collar

83

collar

84

Holding part

85

Flat area

86

Axis of rotation

87

arrow

88

management

89

Space

Claims (19)

1. Rolling unit comprising a rolling tool with at least one rotatably mounted rolling element adapted to be brought forcibly into contact with a workpiece surface, hydraulically actuated means for producing the rolling force, and a device connected to the hydraulically actuated means for producing the desired pressure and volumetric flow of a fluid which actuates the means for producing the rolling force, characterised in that the rolling tool (1) and the device (B-E; G, H) for producing the desired pressure are formed as a structural unit and are connected rigidly to each other, wherein the device for producing the desired pressure is formed as a pump (3,34) and on the suction side for the energy supply the said device is connected to or is connectable to the lubrication circuit or cooling circuit of the machine tool on which the unit is adapted to be used.
2. Rolling unit according to claim 1, characterised in that the rolling tool (1) and the device (B-E; G, H) for producing the desired pressure are disposed each within an independent housing (1′;3′,52′,9′,10′;34′,59), with the housings being rigidly connected to each other.
3. Rolling unit according to one of claims 1 and 2, characterised in that the pump (3,34) is connected to or is connectable to a drive motor (9,58).
4. Rolling unit according to claim 3, characterised in that the pump (3,34) includes a drive shaft (6,32) for connection to the drive motor (9,58), said drive shaft being connectable to or connected to a corresponding take-off shaft (8,60) of the drive motor.
5. Rolling unit according to claim 4, characterised in that the drive motor is a hydraulic motor (9) and for the energy supply is connected to or is connectable to the cooling circuit or lubrication circuit of the machine on which the unit is adapted to be used.
6. Rolling unit according to one of claims 1 to 5, characterised in that the device for producing the desired pressure comprises a hydraulic pump (3) and a hydraulic motor (9), wherein pump and motor are arranged in a common housing (B,C,D) or in separate housings (3′,52′,9′) which are connected rigidly to each other.
7. Rolling unit according to claim 6, characterised in that the device additionally includes a pressure reservoir (29).
8. Rolling unit according to one of claims 1 to 7, characterised in that the rolling unit is divided into functional groups (A-H), wherein each functional group has its own housing (1′,3′,52′,9′,10′, 34′,59) with at least one plane contact surface, and wherein, for the production of the rolling unit, all housings of the functional groups (A-E; F-H) are functionally positioned in contact with each other by means of the plane contact surfaces and are rigidly connected to each other.
9. Rolling unit according to one of claims 1 to 8, characterised in that the pump (3) is a piston pump.
10. Rolling unit according to claim 9, characterised in that the piston (23) of the piston pump (3) is displaced by means of a rotationally driven or rotationally drivable cam or eccentric (19).
11. Rolling unit according to claim 4, characterised in that the drive motor (58) is an electric motor.
12. Rolling unit according to one of claims 1 to 8, characterised in that the pump (34) is a geared pump.
13. Rolling unit according to one of claims 1 to 12, characterised in that the rolling unit comprises a clamping shaft (11,11′) arranged to be mounted on a tool magazine, on a turret head or in some other tool receiver (57) of the machine on which the unit is adapted to be used.
14. Rolling unit according to claim 13, characterised 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 by means of a coupling (33).
15. Rolling unit according to claim 7, characterised in that the pressure reservoir (29) is a spring pressure reservoir.
16. Rolling unit according to one of claims 1 to 15, characterised in that each rolling element (2) is guided, supported and rotatably mounted in a roller head (44′), wherein the roller head (44′) is formed as a hydrostatic bearing for the rolling element (2), and wherein the roller head is connected to or can be connected to a communication channel at the pressure side (4) of the pump (3).
17. Rolling unit according to one of claims 1 to 16, characterised in that each rolling element (2) is guided, supported and rotatably mounted in a roller head (44), wherein the roller head (44) is arranged at the free end of a piston rod (42) of a piston-cylinder unit (41,42,45) whose cylinder chamber (40) on the side of the piston (41) remote from the piston rod (42) can be connected to or is connected to the pressure side (4) of the pump (34).
18. Rolling unit according to claim 1, characterised in that the rolling tool (1) is connected to a locating shaft (62) for a working spindle of a machine tool (63), wherein at least one piston pump (65) with an actuating cam (66) is provided in the intermediate zone (64) between tool (1) and locating shaft (62), wherein said at least one piston pump is connected on the pressure side to the hydraulically actuated means for producing the rolling force and on the suction side to fluid supply means, wherein the intermediate zone (64) with the actuating cam (66) is surrounded by a ring (67) which is mounted rotatably in this intermediate zone (64) and which has an internal curved track (68) for the actuation of the actuating cam (66), and wherein the ring (67) is prevented from involuntary rotation by means of a torque pin (69).
19. Rolling unit according to claim 18, characterised in that a pressure reservoir (70) is provided connected to the pressure side of the pump (65) and circulating with the rolling tool (1).

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