ROBOT KR 350. Description. Manipulator. Ro/Me/02/ en. 1of 16

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1 ROBOT KR 50 Description Manipulator of 6

2 e Copyright KUKA Roboter GmbH This documentation or excerpts therefrom may not be reproduced or disclosed to third parties without the express permission of the publishers. Other functions not described in this documentation may be operable in the controller. The user has no claim to these functions, however, in the case of a replacement or service work. We have checked the content of this documentation for conformity with the hardware and software described. Nevertheless, discrepancies cannot be precluded, for which reason we are not able to guarantee total conformity. The information in this documentation is checked on a regular basis, however, and necessary corrections will be incorporated in subsequent editions. Subject to technical alterations without an effect on the function. PD Interleaf of 6

3 Contents General... 5 Description Wrist Arm Wrist axis motor units A 4 to A Link arm Main axis motor units A to A Rotating column....5 Base frame....6 Hydropneumatic counterbalancing system Functional principle Gearing... 6 Accessories Working range limitation for A to A Working range monitoring for A to A... 6 of 6

4 Description 4of 6

5 General Valid for KR 50/ KR 50 L80/ KR 50 L40/ General The robot system consists of the manipulator (= robot), control cabinet and connecting cables (Fig. ). The manipulator is dealt with in this Doc. Module. The control cabinet and connecting cables are described in other Doc. Modules. In the following description, only the KR 50 will be depicted in the illustrations. The information in the description applies to all robot variants, however. Exceptions to this will be clearly marked. Manipulator Control cabinet Connecting cables Fig. Robot system KR 50/ 5of 6

6 Description Description This section is subdivided in accordance with the breakdown of the manipulator into its main subassemblies.. Wrist The robot is equipped with a triple--axis in--line wrist (Fig. ) for a payload of 50, 80 or 40 kg, depending on the type. The wrist is fastened onto the arm or the arm extension via the flange (4). The axes 5, 6 and 4 are driven by shafts (,, ). An end effector can be attached to the mounting flange (5) of axis 6. Each axis has a measuring device (6), through which the mechanical zero of the respective axis can be checked by means of an electronic probe (accessory) and transferred to the controller. For the directions of rotation, angles of rotation and speeds of the axes see robot Doc. Module Technical Data. The structure and functional principle are described in the robot Doc. Module Description, In--line Wrist 50 kg. 4 5 Z View Z Shaft Shaft Shaft 4 Flange 5 Mounting flange 6 Measuring device 6 Fig. In--line wrist 6of 6

7 Description (continued). Arm The arm assembly (Fig. /) embodies the driven element of axis of the robot. The arm is flange--mounted to the side of the link arm (6) through a gear unit with integrated bearings and is driven by main axis motor unit A (5). The effective software swivel range extends from +60 to --84, referred to the mechanical zero position of axis, which is given when there is an angle of 90 between the longitudinal axes of the arm and link arm (as shown in Fig. ). The swivel range is limited by mechanical limit stops with a buffer function in addition to the software limit switches. Attached to the rear of the arm housing are the motor units for wrist axes 4 to 6. The arm housing consists -- as do the housings of the link arm and rotating column -- of a light alloy construction optimized by means of CAD and FEM. Mounted on the side of the arm is the counterweight (7) for the counterbalancing of masses about axis. Mounted on the front end of the arm via a standardized interface is the in--line wrist (), which is driven by the servomotors () through push--on shafts (4) located inside the arm Servomotors 5 Main axis drive unit A Arm 6 Link arm In--line wrist 7 Counterweight 4 Shafts Fig. Arm with turning range 7of 6

8 Description.. Wrist axis motor units A 4 to A 6 The wrist axes are driven by three servomotors. These motor units are screwed to the arm (Fig. 4/) via a common baseplate. The servomotors (, ) for axes 4, 5 and 6 are of the same design. Wrist axes 4 and 5 are driven by universal shafts (4). Wrist axis 6 is driven directly by servomotor A 6 () through a push--on shaft (5). Each servomotor for the wrist axis drives consists of a brushless AC motor with a permanent--magnet single--disk brake and a hollow--shaft resolver (both integrated into the servomotor). The permanent--magnet single--disk brake performs a holding function when the servomotors are at rest and contributes to the braking of the respective axis in an EMERGENCY STOP. The EMERGENCY STOP function must therefore not be used to stop the robot under normal circumstances. The permanent--magnet single--disk brakes are not safety brakes. A4 A6 A5 4 Servomotor A 4, A 5 Servomotor A 6 Arm 4 Universal shaft 5 Push--on shaft 5 Fig. 4 Wrist axis motor units A 4 to A 6 8of 6

9 Description (continued). Link arm The link arm (Fig. 5/) is the driven element of axis. It pivots about rotational axis () through an effective software range of +0 to --40, referred to the mechanical zero position of axis, which corresponds to the vertical position of the link arm in Fig. 5. The effective software swivel range is limited by mechanical limit stops with a buffer function in addition to the software limit switches Link arm Main axis drive unit A Rotational axis Fig. 5 Link arm with turning range The link arm (Fig. 6/6) contains the gear unit A (5) at its upper end, and the gear unit A () at its lower end. The gear units (5, ) are used both as drive elements and to support the arm (4) and link arm (6). Reference notches (, ) are provided to define the mechanical zero position of axes and. The cables for energy supply and signal transmission are routed in the interior of the link arm housing from the rotating column to the arm (see robot Doc. Module Description, Electrical Installations ). 9of 6

10 Description Gear unit A 5 Gear unit A Reference notch A 6 Link arm Reference notch A 7 Rotational axis 4 Arm Fig. 6 Structure of link arm.. Main axis motor units A to A The robot axes, and are driven by servomotors as shown in Fig. 7. Each servomotor for the main axis drives consists of a brushless AC motor () with a permanent--magnet single--disk brake () and hollow--shaft resolver (), both integrated. The servomotors for axes, and are of the same design, but have different power ratings. The permanent--magnet single--disk brake performs a holding function when the servomotors are at rest and contributes to the braking of the respective axis in an EMERGENCY STOP. The EMERGENCY STOP function must therefore not be used to stop the robot under normal circumstances. The permanent--magnet single--disk brakes are not safety brakes. Servomotor Permanent--magnet single--disk brake Hollow--shaft resolver Fig. 7 Servomotor for main axis drives 0 of 6

11 Description (continued).4 Rotating column The rotating column (Fig. 8/) is the assembly located between the link arm and the base frame. Screwed to the base frame (4) through a special reduction gear unit (), which allows it to rotate, it performs movements about rotational axis (). It has an effective software turning range of 85 in both the (+) and (--) directions, measured from the mechanical zero position of axis (6). This range is limited by mechanical limit stops with a buffer function in addition to the software limit switches. This limit stop system operates with a trailing stop acting on both sides, which is installed in the base frame and mechanically limits the large turning range of 85 in both directions Rotational axis Rotating column Special reduction gear unit 4 Base frame 5 Main axis drive unit A 6 Zero position A Fig. 8 Rotating column with turning range of 6

12 Description Installed in the rotating column is the servomotor for axis (Fig. 9/), together with the special reduction gear unit (). The servomotor for axis () and the associated special reduction gear unit (4) are mounted to the side. The complete electrical installations of the robot are routed within the rotating column (see robot Doc. Module Description, Electrical Installations ). 4 Servomotor A Servomotor A Special reduction gear unit A 4 Special reduction gear unit A Fig. 9 Structure of rotating column.5 Base frame The base frame (Fig. 0) is the stationary part of the robot, on which the rotating column turns with the link arm, the arm and the wrist. Its base flange (7) features through--holes (6) for holding the robot down, and two locating boreholes (8), with which the robot can be placed on two locating pins (accessories, see also robot Doc. Module, Installation, Connection, Exchange ). Attached to the flange (5) in the base frame housing () is the special reduction gear unit (4) of axis. Also integrated into this flange (5) is the double--acting trailing stop, which together with a stop block on the rotating column mechanically safeguards the software--limited movement range of 70 about rotational axis. In the base frame, the installation cables leading to the rotating column are routed stress-- free about rotational axis of the robot in a flexible tube. If an energy supply system is used, these supply lines are also routed through the base frame in a second flexible tube of the same type. The space between the rotating column and the base frame is coated with cable grease and is provided with a detachable, one--piece cover (). The sockets for the connecting cables from the robot to the control cabinet are located on the three junction boxes (). of 6

13 Description (continued) Junction boxes (x) 5 Flange Base frame housing 6 Through--holes (8x) Cover 7 Base flange 4 Special reduction gear unit 8 Locating boreholes (x) Fig. 0 Structure of base frame of 6

14 Description.6 Hydropneumatic counterbalancing system The robot is equipped with a closed hydropneumatic counterbalancing system for compensating the load moment of axis. The robot is provided with the appropriate system variant depending on whether it is mounted on the floor or on the ceiling (Fig. ). The system is installed between the rotating column (0) and the link arm (). The principal components of the counterbalancing system are the counterbalancing cylinder (5), the articulated head (7), the bladder accumulator (4) and the pin (9). The fittings (6) installed on the counterbalancing cylinder (5) are used for the maintenance and monitoring of the counterbalancing system. Improper handling of the counterbalancing system can lead to injury, as the diaphragm accumulator is pressurized..6. Functional principle The starting position for the following functional description is the mechanical zero position of axis, i.e. the link arm () is vertical and the pivot points bearing, rotating column () and bearing, link arm () and the rotational axis of axis () all lie on a straight line. In this position, the piston of the counterbalancing cylinder (5) is in the rearmost position and the oil pressure displayed on the pressure gage (8) corresponds to the set pressure. If the link arm is now moved forwards, the piston is also drawn forwards and the oil in the rod chamber is forced into the diaphragm accumulator against the nitrogen pressure. As a result, as the stroke increases, so a corresponding counterpressure, and thus a counterforce, is built up. This stroke--dependent counterforce counteracts the weight forces about axis. If the link arm is moved backwards again, the volume of the rod chamber increases and the oil can flow back into the counterbalancing cylinder (5) under the pressure in the diaphragm accumulator (4). The pressure decreases and the counterforce diminishes until the link arm reaches the vertical position again. The functional sequence is the same if the link arm is moved backwards from the zero position. With the counterbalancing system for ceiling--mounted robots, the sequence is comparable but differs in that pressure is built up at the opposite end of the counterbalancing cylinder. 4 of 6

15 Description (continued) Bearing, link arm Link arm Rotational axis 4 Diaphragm accumulator 5 Counterbalancing cylinder 6 Fittings 7 Articulated head 8 Pressure gage 9 Pin 0 Rotating column Bearing, rotating column 9 8 Fig. Hydropneumatic counterbalancing system for floor--mounted robots 5 of 6

16 Description.7 Gearing The robot is driven in the main and wrist axes through special planetary gears. The multi-- stage gear units of all axes are identical in function, but differ in size. In the main axes, the servomotors engage directly with the gear unit, whereas in the wrist axes, universal shafts and spur gear stages, toothed belts or bevel gears intervene. Accessories. Working range limitation for A to A Mechanical stops for task--related limitation of the respective working range for axes to can be supplied as the Working range limitation accessory (see robot Doc. Module, Working Range Limitation ).. Working range monitoring for A to A Axes to can be equipped with position switches and slotted rings as accessories to which adjustable cams are attached (see robot Doc. Module, Working Range Monitoring ). This allows the position of the robot to be continuously monitored. Up to three sectors can be monitored on A and A, and up to two sectors on A. If axes and are equipped with working range monitoring, an energy supply system with an additional control cable is required. 6 of 6