CN111659916A

CN111659916A - Clamping device

Info

Publication number: CN111659916A
Application number: CN201910577243.4A
Authority: CN
Inventors: 卡尔·海斯坦德
Original assignee: Marcus Thomas Hestand
Current assignee: Marcus Thomas Hestand
Priority date: 2019-03-06
Filing date: 2019-06-28
Publication date: 2020-09-15
Also published as: DE102019105643A1

Abstract

Clamping device (4), in particular for a machine tool (9), which is provided, for example, with a power chuck (100) for clamping a workpiece (10) and whose clamping jaws (6) can be adjusted by means of the clamping device (4) via axially adjustable tie rods (7,7 ') as actuating elements, wherein the clamping device (4) has a switchable drive motor (8) which is connected to the clamping device (4) via two transmission chains (111,113) for triggering a clamping movement, a movement converter (102) for converting an adjusting movement of a rotor shaft (25) of the drive motor (8) into an axial adjusting movement of the tie rods (7, 7') which is necessary for actuating the clamping jaws (6), and a force accumulator for maintaining the clamping force, wherein the two transmission chains (111,113) are formed by a first and a second, in each case, by two belt pulleys (12,14 or 11,13) and a toothed belt or drive belt (37), 38) the belt transmission devices (121,123) are formed.

Description

Clamping device

Technical Field

The object of the invention is a clamping device, in particular for a machine tool, according to the preamble of patent claim 1.

Background

Such clamping devices are provided, for example, with a power chuck for clamping a workpiece, the clamping jaws of which can be adjusted by means of the clamping device via axially adjustable tie rods as actuating elements. For this purpose, the clamping device has a switchable drive motor which is connected to the clamping device via a transmission chain for triggering a clamping movement, and a movement converter for converting an actuating movement of a rotor shaft of the drive motor into an axial actuating movement of the tie rod which is necessary for actuating the clamping jaws. Additionally, an accumulator is used to maintain the clamping force.

EP 3127640 a1 discloses a clamping device, in particular for a clamping tool of a machine tool, which is provided with a power chuck for clamping a workpiece, the clamping jaws of which can be adjusted by means of the clamping device via axially adjustable tie rods as actuating elements.

For this purpose, the clamping device has a switchable drive motor connected to the clamping device via a transmission chain for triggering a clamping movement, a movement converter for converting an actuating movement of a rotor shaft of the drive motor into an axial actuating movement of a pull rod, which is necessary for actuating the clamping jaws, and an accumulator for maintaining the clamping force.

On the externally mounted servomotor, a first pulley on its rotor shaft with a rotor hub, a second pulley, a rotatable, planar coupling unit and a medium-actuated cylinder and a cylinder housing are supported.

The two drive chains are formed by a first and a second belt drive, each of which is formed by two belt pulleys and a toothed belt and a drive belt guided via these belt pulleys. These toothed belts or drive belts are connected in a rotationally fixed manner to the clamping tool of the spindle.

In the clamping position of the clamping device, the two belt discs arranged on the bearing hub can be coupled to each other by means of a servo device. Here, it is a medium-operated servo device for coupling two pulleys, whose cylinder and its cylinder housing are supported in a rotatable manner on a rotor hub of a rotor. In the decoupled state of the two pulleys, the first pulley, which is connected to the rotor shaft via the rotor hub, can be twisted relative to the second pulley, wherein the input pulley of the clamping tool is twisted and its clamping force is changed.

After the desired higher/lower clamping force of the clamping tool has been reached, the two pulleys are coupled again with the planar toothing and the clamping force reached by the clamping tool at a certain rotational speed is ensured by the mutual tensioning of their belts.

In the clamped operating state, the rotor shaft of the electric motor rotates together with the rotor hub, the first belt pulley connected in a rotationally fixed manner thereon, the coupled second belt pulley, and the coupling piece of the planar toothing rotates together with the spindle and the clamping tool, wherein the total weight and tensile forces of the two belts act on the rotor shaft and on the motor bearing.

In the case of all further known actuating devices, the electric motor is permanently rotated at a certain rotational speed and with a torque which is inactive for the clamping tool and requires and consumes electrical energy in order to obtain the clamping force of the clamping tool.

In this clamping device, it is disadvantageous that the motor rotor of the externally mounted adjustable servomotor must be permanently driven synchronously with the spindle speed by the energy input and therefore consumes energy. If the servomotor is in turn driven by the spindle of the machine, it generates an electric current, wherein the torque for generating the electric current has to be applied by the spindle motor of the machine. The resulting currents of the servo motors have to be offset in a complex manner, since no input into the power grid is possible.

On the permanently rotating rotor shaft, all parts of the switching unit are cantilevered and wear-resistant on the motor bearing by the weight and tension of the two belts clamped against each other.

A stop of the motor rotor in the case of the rotational speed of the spindle is not possible, since the first belt pulley is connected in a rotationally fixed manner via a belt to a pulley of the rotating clamping tool and the motor rotor rotates at the same rotational speed.

Adjustment of the two belt pulleys relative to one another is not possible without disengagement of the planar toothing.

Disclosure of Invention

The object of the invention is therefore to design a clamping device of the type mentioned above in such a way that the control and construction costs can be kept extremely low, whereby the susceptibility to interference should be reduced to a minimum, so that reliable energy-free operation of the clamping device is ensured over a long period of time.

The object on which the invention is based is achieved by the features of the independent patent claim 1, while advantageous embodiments and refinements of the invention are evident from the dependent claims.

According to the invention, the machine tool is screwed to a distributor housing, with the housing side wall of which the rotor shaft projects into the interior of the distributor housing and drives the output pulley of the first belt drive via at least one toothing for triggering a clamping movement relative to the connecting pulley of the second belt drive.

The first pulley for adjusting the clamping force of the clamping tool can thus be separated from the motor shaft, i.e. the rotor shaft of the motor can be separated in the coupled state of the two pulleys. Thus, a large locking force no longer acts on the axial support of the electric machine in the coupled state via the flat toothing of the two toothed pulleys.

A drive flange is arranged on the rotor shaft of the drive motor in a rotationally fixed manner, which drives an output pulley of the first belt drive via a gear for triggering the clamping movement.

An input shaft is likewise rotatably supported on the rotor shaft, on which the output pulley of the first belt drive is rotatably supported and the connecting pulley of the second belt drive is supported in a rotationally fixed manner.

The drive flange is rotatably supported in an opening of a side wall housing of the distributor housing and is connected in a rotationally fixed manner to a rotor shaft of the drive motor.

The drive flange shaft has a bolt which is offset parallel to the rotational axis and on which a coupling gear wheel is rotatably supported, which meshes with an intermediate gear wheel which is rotatably supported on the input shaft of the transmission and meshes with a further double gear wheel which is rotatably supported on the bolt of the side housing wall and which in turn meshes with a toothing of the connecting hub, which toothing is connected in a rotationally fixed manner to the output pulley.

The double gear has two different diameters with correspondingly different toothing, wherein the larger diameter toothing meshes with the toothing at the outer periphery of the input shaft.

The other double gearwheel, which is rotatably supported on the bolts of the side wall housing, likewise has two different diameters with correspondingly different toothing, wherein the smaller-diameter toothing meshes with the toothing of the intermediate gearwheel and the larger-diameter toothing meshes with the toothing of the connecting hub.

A further feature of a preferred embodiment of the invention is that the rotor shaft is connected in a rotationally fixed manner to a flange which can be coupled in a form-fitting manner to the output pulley by means of a pressure cylinder via an axially displaceable coupling disk.

The flange has teeth in the direction of the coupling disk, which can be positively connected to the teeth of the coupling disk.

The pressure cylinder is formed by a piston which is inserted into the cylinder and is acted upon on one side by a pressure medium, wherein the axially displaceable piston rests on the coupling disk in the pressure-loaded state.

In the case of a pressure-loaded release, the piston returns into the rest position with a spring return force, and the coupling disk likewise returns into the rest position with a return force of the further spring.

The coupling disk has a toothing which, in the rest position of the coupling disk, interacts with a toothing of a connecting cam, which is connected to the connecting pulley in a rotationally fixed manner.

The inventive object of the invention is to be found not only in the object of the individual patent claims but also in the combination of the individual patent claims with one another.

All the matters and features disclosed in the attached claims, including the abstract, particularly the spatial arrangements shown in the drawings, are to be protected as important for the invention, insofar as they are novel individually or in any combination with respect to the prior art.

Drawings

The invention is further illustrated below by means of the attached drawings showing various implementation approaches. Further features and advantages of the invention which are essential to the invention are apparent from the drawing and its description.

If individual objects are referred to as "important" or "important" for the present invention, this does not mean that the objects must form the objects of the independent claims. This is only to be determined by the correspondingly adapted text of the independent patent claims.

Wherein:

FIG. 1: a cross-sectional illustration of the clamping device is shown,

FIG. 2: showing a cross-sectional representation of the dispenser housing (variant 1)

FIG. 3: showing a cross-sectional representation of the dispenser housing (variant 2)

FIG. 4: showing a cross-sectional representation of the dispenser housing (variant 2)

FIG. 5: schematic illustrations of a dispenser housing according to variants 1 and 2 are shown.

Detailed Description

The clamping device 4 shown in fig. 1 and designated by 4 is used to actuate a power chuck 100 arranged on a machine tool 9, in which power chuck 100 a workpiece 10 to be processed is clamped by means of its radially adjustable clamping jaws 6. The clamping jaws 6 of the power chuck 100 can be actuated by an axially adjustable two-part linkage 7, 7' via a deflection lever 101, which is in driving connection with a switchable drive motor 8 via a motion converter 102. By means of the motion converter 102, the rotary adjusting motion of the drive motor 8 is converted into an axial feed motion of the tie rods 7, 7'.

The motor 104 acts on the machine spindle 103, by means of which the machine tool 9 can be driven.

The clamping device 4 has a housing 107 in which the motion converter 102 and a not shown accumulator are arranged.

On the side facing the machine tool 9, the housing 107 is provided with projecting tabs 116, at which flanges 119 are fixed by means of screws 117. By means of a further screw 118, a flange 119 is mounted at a further flange 120 molded at the machine spindle 103.

The motion converter 102 is supplied with drive energy via a double gear 109 which is in driving connection with the nut 40. By means of the nut 40 of the accumulator 106, to which the spring set, not shown, acts during the clamping process, the introduced rotational movement of the double gear 109 is transmitted to the spindle nut 108, which is displaced in the axial direction and which transmits this movement to the tie rod 7' connected thereto, which converts this movement in the rotational direction into an axial feed movement.

An externally arranged drive and distributor housing 1, 1' is screwed in a stationary manner on the headstock of the machine tool 9. A plurality of

gears

32,33,34 which mesh with one another are supported in the distributor housing 1, and a drive flange with an intermediate opening 80, in which the rotor shaft 25 of the drive motor 8 can be moved in a rotationally fixed manner, is supported in the region of the side wall housing 23.

The motor rotor shaft 25 is stopped in this operating state when no electrical energy is available.

The drive motor 8 in the dispenser housing 1 is in driving connection with the gripping device 4 via two

drive chains

111, 113. An input shaft 35 is arranged rotatably on the rotor shaft 25 of the drive motor 8 and is placed on a sleeve 76 of the drive flange 30 by means of a bearing 51. On the input shaft 35, the output pulley 12 and the connecting pulley 14 of the two belt drives 121,123 are arranged, which are formed together with the drive chains 111,113, the spindle pulley 13, the input pulley 11 and the belt drives 121,123 formed by the toothed belts or

drive belts

37,38 guided via the same. One of the pulleys, i.e. the connecting pulley 14, is in turn connected in a rotationally fixed manner to the input shaft 35 by means of a spline connection 48. In contrast, the output pulley 12 is rotatably supported on the input shaft 35.

The

belt pulley

12 or 14 is in driving connection with the

belt pulley

11 or 13 via a toothed belt or

drive belt

37 or 38, which is coupled to a drive element of the clamping device 4.

The output pulley 11 is rotatably supported on a hollow shaft 110 by means of a rolling bearing 105, which meshes with a double gear 109, which has a toothing 73 at this location, via a toothing 114 provided at a projection 112. The double gear 109 has two different diameters with correspondingly two different toothing 73, 74. On its side facing the clamping device, the double gear has a further toothing 74, which engages into the toothing 99 of the spindle nut 108.

In contrast, the belt pulley 13 is firmly mounted on the hollow shaft 110 by means of screws 115.

Here, the output pulley 12 acts as an adjustment wheel for the adjustment movement of the jaws of the power chuck 100. The rotor shaft 25 of the drive motor 8, which is fastened to the distributor housing 1, projects into the distributor housing 1 through an opening 80 in the housing side wall 23. In the region of the opening 80, in the interior of the distributor housing 1, the rotor shaft 25 is surrounded by a drive flange 30, which is formed by a sleeve 76 and a disk 77 extending in the circumferential direction thereof, which is integrally connected to the sleeve 76. The end of the sleeve 76 facing the drive motor 8 projects into an opening 80 of the motor-side housing side wall 23 and is supported against the opening 80 via a roller bearing 79.

The drive flange 30 is connected in a rotationally fixed manner to the rotor shaft 25 via a spline connection 70.

In order to brake the drive flange 30 when the drive motor 8 is switched off, the drive flange 30 can be automatically locked by a recess 46 which is machined into the drive flange and a plurality of spring-loaded compression bolts 45 which are distributed over the circumference and into which blind holes 69 which are arranged in the housing inner wall 23 are inserted. In the case of switching off the drive motor, the pressure bolt 45 is therefore pressed into the recess 46 by an axial movement to the right (triggered by the force of the spring), so that the drive flange 30 is braked and secured against twisting.

The operating position of the clamping device 4 in the operating process is therefore first explained with reference to fig. 1, in which the workpiece 10 clamped in the power chuck 100 can be processed according to the regulations and the drive motor, which is designed as an ac or dc motor, is stopped and no energy is supplied or discharged.

If the adjustment of the gripper jaws 6 is to be carried out in order to release the workpiece 10 and, if appropriate, to grip another workpiece, the output pulley 12 is twisted relative to the connecting pulley 14 by means of the drive motor 8. The belt drive 121 via the clamping device 4 is thus supplied with energy by means of the drive motor 8. In this case, the belt pulley 12 is twisted and via the input pulley 11 connected thereto the double gear 109 is twisted, which drives the nut 40, so that the tie rod 7' is axially displaced by this nut and the clamping jaws 6 are adjusted inward or outward. Thus, a workpiece may be removed or another workpiece may be inserted. After the end of the operating process, the drive motor is switched off again.

In order to introduce or change the clamping force of the clamping jaws 6, the torque of the drive motor 8 is thus transmitted. In this case, the drive flange 30 is twisted together with the double gear 32, whereby likewise the intermediate gear 34, the double gear 33 and the connecting hub 15 are twisted together with the output pulley 12. The connecting hub 15 is connected in a rotationally fixed manner to the output pulley 12 and is supported in an opening 81 of the belt-side wall housing 28 via a rolling bearing 49. Thereby, the output pulley 12 is twisted with respect to the connecting pulley 14.

In the case of a movement of the drive flange 30, the pressure bolt 45 is likewise pressed out of the recess 46.

In the event of reaching the set torque for increasing or decreasing the clamping force of the clamping tool 6,100, the drive motor 8 is switched off again and the drive flange 30 is stopped, wherein the hold-down bolt 45 locks again in the recess 46 and holds the drive flange against further twisting.

In this operating state, the two belt pulleys 12 and 14 are again rotated synchronously with one another and the clamping device 1 is locked, so that the treatment process can be carried out.

Different sensors are provided for monitoring the respective operating state. The tie rod 7 thus functions together with a sensor 20, by means of which its adjustment distance can be controlled. Likewise, the motion converter 102 is equipped with a sensor 19 in order to control the adjustment distance of the nut 40.

Figure 2 shows a detailed view of the dispenser housing 1. The disks 77 of the drive flange 30 have bolts 31, which project parallel to the rotor shaft 25 in the direction of the

pulleys

12,14, offset axially with respect to the rotational axis 56. On this bolt, the double gear 32 is rotatably supported. The double gear 32 has two different diameters with correspondingly two

different toothing

52, 53. Here, the larger-diameter toothed portion 52 meshes with the toothed portion 82 of the input shaft 35. The smaller-diameter toothing 53 meshes with a toothing 84 of the intermediate gear 34, which is rotatably supported via a rolling bearing 83 on the input shaft 35 of the transmission, which extends concentrically thereto, and rotates about the rotational axis 56.

The other double gear 33 is rotatably supported on the bolt 36 at the fixed side housing wall 28 with its shaft offset parallel to the rotational axis 56 and has a smaller diameter in the direction of the intermediate gear 34 and a larger diameter in the direction of the connecting hub 15. The smaller diameter has a toothing 56 with which the double gear 33 meshes with a toothing 84 of the intermediate gear 34. The larger diameter has a toothing 54 with which the double gear 33 meshes with the toothing 39 of the connecting hub 15.

The connecting hub 15 is drivingly connected with the output pulley 12 via screws 55. The output pulley 12 is connected via a belt 37 with the input pulley 11 of the clamping tool arranged on the spindle and its nut 40.

The pulley 12 of the belt drive 111 is rotatably supported on the input shaft 35 via the connecting hub 15 and by means of the rolling bearing 49.

The connecting pulley 14 is connected to the main shaft pulley 13 via a belt 38 and rotates together with the main shaft.

In the initial state, the output pulley 12 and the connecting pulley 14 rotate at the same speed, wherein the motor shaft 25 is stopped and the two

pulleys

12,14 rotate synchronously.

In this operating state, the motor shaft 25 is in a stationary state, wherein the drive flange 30 connected to it in a rotationally fixed manner via the splined connection 70 and the bolts 31, which are machined into the drive flange 30 at a radial distance from the rotor shaft 25, are likewise in a stationary state.

On the bolt 31, which is parallel to the rotor shaft 25, the double gear 32 is rotatably supported via a bearing 72. Despite the stationary state of the bolt 31, the double gear 32 rotates together with the drive flange 30 with the intermediate gear 34 due to the movement of the input shaft. The reason is the toothing 84 of the input shaft 35, which meshes with the toothing 53 of the double gear 32. The rotational movement of the double gear 32 is decoupled from the bolt 31 by the bearing 72.

Further, the input shaft 35 is supported on the sleeve 76 via a bearing 51. No or only very little transmission of rotation between the

parts

30 and 35 takes place here.

If a setting movement of the headstock should occur at this time, a rotational movement is transmitted via the servomotor 8 to the rotor shaft 25, which in turn drives the drive flange 30.

Thus, the output gear 12 can be moved relative to the connecting pulley 14.

Here, an upshift gear is present at the

toothing

52,82 and a downshift gear is present at the

toothing

53,84, which in turn is compensated by the

toothing

56,84, thereby in turn forming a downshift gear. It is thus possible to build a so-called synchronous transmission in which the rotary motion of the rotor shaft 25 is converted directly into the rotary motion of the output gear 12 and no speed increase occurs.

Fig. 3 shows an embodiment of the distributor housing 1' in which the double and intermediate gears 34 are not installed. In this case, the rotor shaft 25 of the drive motor 8 again projects into the distributor housing 1', which in the example shown according to fig. 3 is stopped and in which the double disk 29 is not in contact with the motor shaft 25.

The motor shaft 25 is supported in a rotationally fixed manner in the cylindrical bore 24 of the flange 90, wherein the flange 90 is located in the opening 89 of the housing side wall 23 and is supported by means of the bearing 47 relative to the housing side wall 23. In addition, the housing side wall 23 has a sleeve-like projection 64 which projects into the interior of the dispenser housing 1' and which receives a likewise sleeve-like collar 90. The bearing 47 is located on the front side of the projection 64, wherein the flange 90 is radially enlarged in this region and has a disk-shaped widening 26, which rests on the rear side on the bearing 47.

Between the outer periphery of the flange 90 and the inner wall of the opening 89 there is a sealing element 43.

The drive flange 90 has, at the radially outer edge of the disk-shaped widening 26, a toothing 88 at the end face oriented in the direction of the double disk, which in the operating state according to fig. 3 has a spacing from the oppositely oriented toothing 57 of the coupling disk 29.

The coupling disk 29 has teeth 58 in the opposite direction, which engage with teeth 87 of the connecting cams 85. The connecting cam 85 is connected to the belt pulley 14 in a rotationally fixed manner.

The coupling disk 29 is connected to the hollow drive shaft 27 via screws 59. For this purpose, the screw 59 is supported in a movement-proof manner in a blind hole 92 of the hollow drive shaft 27 and in a movable manner in a blind hole 93 of the coupling disk 29. The coupling disk 29 is thus displaced relative to the screw 59, which, however, is always in contact with the coupling disk 29 and drives it about the axis of rotation 56.

The connecting cam 85 is supported on the hollow drive shaft 27 via the rolling bearing 67.

The drive sleeve 27 is connected in a rotationally fixed manner to the output pulley 12 via a spline 60. In the operating state shown according to fig. 3, the

pulleys

12 and 14 rotate synchronously.

Below the splines 60, the drive hollow shaft 27 is supported on a projection 64 of the housing side wall 23 via a rolling bearing 44.

Fig. 4 shows an operating state in which the drive motor 8 is switched on in order to bring about an adjusting movement of the clamping jaws 6. To this end, the rotor shaft 25 rotates and the drive flange 90 rotates about the axis of rotation 56.

The drive flange 90 with the toothing 88 at its end face oriented in the direction of the coupling disk of the widened portion is brought into engagement with the toothing 57 of the coupling disk 29.

The actuation of the coupling disc 29 uses the pressure cylinder 2, which is supplied with pressure medium via the pressure connection 18. This pressure medium is introduced into the cylinder chamber 91 and pressed against a pressure surface 94 of an axially movable piston 92 inserted in the pressure cylinder. By means of the control valve, the cylinder chamber 91 can be supplied with pressure medium via the pressure connection 18 for feeding to the cylinder in the direction of the arrow 95, i.e. in the direction of the coupling disc 29.

Perpendicular to the longitudinal axis of the cylinder 92, a bolt 96 is brought in the cylinder. At each of the two ends of the screw 96, which project from the cylinder 92, there is a roller bearing 62a, b, which is rotatably supported on the screw.

If the cylinder 92 is now conveyed in the direction of the arrow 95 as a result of the pressure application, the bearings 62a, b likewise move together with the cylinder until they come into contact with the contact surfaces 63 of the coupling disk 29 and the coupling disk likewise moves in the direction of the arrow 95 until the teeth 57 of the coupling disk 29 engage the teeth 88 of the drive flange 90.

In this case, the connection between the toothing 58 of the coupling disk 29 and the toothing 87 of the connecting cam 85 is opened, so that the connection between the output pulley 12 and the connecting pulley 14 is no longer present.

Thus, the rotationally driven drive flange 90 can transmit its rotational movement about the axis 56 to the coupling disk 29.

The coupling disk 29, which is in turn connected to the hollow drive shaft 27 via the screw 59, transmits the rotational movement to the hollow drive shaft 27 and thus likewise to the output pulley 12 connected thereto.

It is therefore possible to move the output pulley 12 relative to the connecting pulley 14 in order to thereby bring about an adjusting movement at the headstock.

If pressure is no longer applied to the cylinder 92, the cylinder is returned to the initial position by the spring force of the spring 65 between the side wall housing 97 and the cylinder.

Likewise, spring 61 acts on coupling disc 29, which moves coupling disc 29 counter to arrow direction 95, wherein

teeth

57,88 are disengaged again and

teeth

58,87 are engaged with each other and thus the two

pulleys

12,14 are again connected to each other and rotate synchronously.

Fig. 5a shows a schematic representation of a dispenser housing according to variant 1 with a mounted transmission.

Fig. 5b shows a schematic representation of a distributor housing according to variant 2 with a pressure cylinder 2 at which pressure medium can be supplied via a pressure connection 18. In this case, the individual processes can be monitored by the sensors 16.

List of reference numerals

1. Distributor housing 1'

2. Pressure cylinder

3. Adjusting unit

4. Clamping device

5. Motion converter

6. Clamping jaw

7. Pull rod 7'

8. Driving motor

9. Machine tool

10. Workpiece

11. Input belt pulley

12. Output belt pulley

13. Main shaft belt pulley

14. Connecting belt pulley

15. Connecting hub

16. Sensor with a sensor element

17. Twist stop

18. Pressure joint

19. Force sensor

20. Displacement sensor

21. Spindle nut

22. Intermediate element

23. Outer cover side wall (Motor side)

24. Drilling holes

25. Rotor shaft

26. Widening part

27. Drive hollow shaft

28. Side shell wall (Belt side)

29. Coupling disc

30. Drive flange

31. Bolt

32. Double planetary gears connected with 30

33. Planetary double gear

34. Intermediate gear (central gear) meshing with 32 and 33

35. Input shaft

36. Bolt

37. Leather belt

38. Leather belt

39. Toothed section

40. Nut

41. Sealing element

42. Sealing element

43. Sealing element

44. Rolling bearing

45. Pressing bolt

46. Groove

Bearing of (90)

48. Spline connection

49. Rolling bearing

50. Rolling bearing

51. Bearing assembly

52. (31) teeth

53. Toothed section

54. Toothed section

55. Screw connection

56. Axis of rotation

57. Plane tooth part

58. Plane tooth part

59. Bolt

60. Spline

61. Spring

62. Bearing a, b

63. Contact surface

Projection of (23)

65. Spring

66. Spline connection

67. Rolling bearing

68. Sliding bearing

69. Blind hole

70. Spline connection

71. Rolling bearing

72. Bearing assembly

73. (of 109)

Tooth portion of (109)

Side of (15)

76. Sleeve pipe

77. Disc with a circular groove

78. Rolling bearing

79. Rolling bearing

80. Opening of the container

81. Opening of the container

82. (of 35)

83. Rolling bearing

84. (of 34) teeth

85. Connecting projection

86. Screw nail

87. (85) teeth

88. (of 26)

89. Opening of the container

90. Flange

91. Volume of cylinder

92. Piston

93. Blind hole

94. Blind hole

95. Direction of arrow

96. Bolt

97. Side housing wall

100. Power chuck

101. Deflection rod

102. Motion converter

103. Machine main shaft

104. Electric machine

105. Rolling bearing

106. Power accumulator

107. Outer casing

108. Spindle nut

109. Double gear

110. Hollow shaft

111. Transmission chain

Claims

1. Clamping device (4), in particular for a machine tool (9), which is provided, for example, with a power chuck (100) for clamping a workpiece (10) and whose clamping jaws (6) can be adjusted by means of the clamping device (4) via axially adjustable tie rods (7,7 ') as actuating elements, wherein the clamping device (4) has a switchable drive motor (8) which is connected to the clamping device (4) via two transmission chains (111,113) for triggering a clamping movement, a movement converter (102) for converting an actuating movement of a rotor shaft (25) of the drive motor (8) into an axial actuating movement of the tie rods (7, 7') which is necessary for actuating the clamping jaws (6), and a force accumulator for maintaining the clamping force, wherein the two transmission chains (111,113) are formed from a first and a second, in each case, by two belt pulleys (12,14 or 11,13) and a belt drive (121,123) which is formed by toothed belts or drive belts (37,38) guided via these belt pulleys, characterized in that a distributor housing (1,1 ') is screwed on the headstock of the machine tool (9), through the housing side wall (23) of which the rotor shaft (25) projects into the interior of the distributor housing (1, 1') and at which the output pulley (12) of the first belt drive (121) is driven via at least one toothing (39,52,54,56,84,82) for triggering a clamping movement of the connecting pulley (14) relative to the second belt drive (123).

2. The clamping device (4) as claimed in claim 1, characterized in that a drive flange (30) is arranged on the rotor shaft (25) of the drive motor (8) in a rotationally fixed manner, which drives an output pulley (12) of the first belt drive (121) via a transmission (15,32,33,34) for triggering the clamping movement.

3. Clamping device according to claim 1 or 2, characterized in that an input shaft (35) on which the output pulley (12) of the first belt drive (121) is rotatably supported and on which the connecting pulley (14) of the second belt drive (123) is supported non-rotatably is supported on the rotor shaft (25).

4. The clamping device (4) as claimed in one of claims 1 to 3, characterized in that the drive flange (30) is rotatably supported in an opening (80) of a side wall housing (23) of the distributor housing (1) and is connected in a rotationally fixed manner to a rotor shaft (25) of the drive motor (8).

5. Clamping device (4) according to one of claims 1 to 4, characterised in that the drive flange (30) has a bolt (31) which is offset in an axially parallel manner with respect to the rotational axis (56), on which bolt a double gear wheel (32) is rotatably supported which meshes with an intermediate gear wheel (34) which is rotatably supported on an input shaft (35) of the transmission and meshes with a further double gear wheel (33) which is rotatably supported on a bolt (36) of the side housing wall (28) and which in turn meshes with a toothing (39) of the connecting hub (15) which is connected rotationally fixed to the output pulley (12).

6. The clamping device (4) as claimed in one of claims 1 to 5, characterized in that the double gear (32) has two different diameters with correspondingly different toothing (52,53), and the toothing (52) of the larger diameter meshes with the toothing (82) at the outer circumference of the input shaft (35).

7. Clamping device (4) according to one of the claims 1 to 6, characterized in that the double gear (33) has two different diameters with respective different toothing (56,54), with the smaller diameter toothing (56) meshing with the toothing (84) of the intermediate gear (34) and the larger diameter toothing (54) meshing with the toothing (39) of the connecting hub (15).

8. Clamping device (4) according to claim 1, characterised in that the rotor shaft (25) is connected in a rotationally fixed manner to the flange (90), which can be coupled in a form-fitting manner to the output pulley (12) by means of a pressure cylinder (2) via an axially displaceable coupling disk (29).

9. The clamping device (4) according to claim 1 or 8, characterised in that the flange (90) has the toothing (88) in the direction of the coupling disk (29), which can be positively connected with the toothing (57) of the coupling disk (29).

10. The clamping device (4) according to one of claims 1,8 or 9, characterised in that the pressure cylinder (2) is formed by a piston (92) which is inserted in the cylinder and can be acted on one side by a pressure medium.

11. The clamping device (4) according to one of claims 1,8 to 10, characterized in that an axially movable piston (92) rests at 63 at the coupling disc (29) via the ball bearings 62a/b in the case of pressure loading.

12. The clamping device (4) according to one of claims 1,8 to 11, characterized in that the piston returns into the rest position in the case of a return force of the spring (65) in the case of a pressure-relieved loading.

13. The clamping device (4) according to one of claims 1,8 to 12, characterised in that the coupling disk (29) returns into the rest position in the event of a return force of the spring (61) in the event of a pressure-relieved loading.

14. The clamping device (4) as claimed in one of claims 1,8 to 12, characterized in that the coupling disk (29) has a toothing (58), which in the rest position of the coupling disk (29) interacts with a toothing (87) of a connecting lug (85), which is connected in a rotationally fixed manner to the connecting pulley (14).