A MOVEMENT SIMULATOR

Abstract

The invention is directed to a movement simulator (1) comprising of a moveable support (2) having three translational degrees of freedom connected to a base (3) by means of three actuators (4), wherein each actuator (4) comprises a rotating shaft (5) having two outer ends (6,7) and comprising two spaced apart cranks (10,11), an electric motor (21) comprising a rotor (22) and a stator (23), a support structure (8,9) comprising bearings (26,27) for the rotating shaft (5). The support structure is connected to the base (3), a pair of links (12,13) connecting the cranks (10,11) of shaft (5) to the moveable support (2). One crank (10) is positioned at one outer end (6) of the shaft (5) and the other crank (11) is positioned at the opposite outer end (7) of the shaft (5). Part of the rotating shaft (5) is the rotor (22) of the electric motor (21).

Claims

1. A movement simulator comprising of a moveable support having three translational degrees of freedom connected to a base by means of three actuators, wherein each actuator comprises a rotating shaft having two outer ends and comprising two spaced apart cranks, an electric motor comprising a rotor and a stator, a support structure comprising bearings for the rotating shaft, which support structure is connected to the base, and a pair of links connecting the cranks of shaft to the moveable support, wherein one crank is positioned at one outer end of the shaft and wherein the other crank is positioned at the opposite outer end of the shaft and wherein part of the rotating shaft is the rotor of the electric motor.

2. A movement simulator according to claim 1, wherein the support arrangement comprises two spaced apart supports defining a part of the shaft between the two supports and two parts the shaft including the two ends of the shaft extending axially outwardly from the supports.

3. A movement simulator according to claim 2, wherein the part of the rotating shaft which is the rotor of the electric motor is positioned between the supports.

4. A movement simulator according to claim 3, wherein the stator of the electric motor is connected to one or both of the two spaced apart supports.

5. A movement simulator according to claim 1, wherein the two links are connected to the cranks by means of at least 2 degree of freedom joints.

6. A movement simulator according to claim 1, wherein the crank is an excenter.

7. A movement simulator according to claim 5, wherein the two links are connected to the cranks by means of an inverted ball joint.

8. A movement simulator according to claim 1, wherein each link comprises a push pull rod and a flex plate, and the flex plates of the links are connected to the cranks by means of preloaded bearings.

9. A movement simulator according to claim 1, wherein the radial distance (y) between the axis of rotation (x) of the shaft and the joint center of the joint connecting the crank and the link is between 5 and 20 mm.

10. Use of a movement simulator according to claim 9 as a shaker as part of a helicopter movement simulator.

11. A movement simulator comprising of a moveable support having three translational degrees of freedom connected to a base by means of three torque devises comprising a rotating shaft having an excenter at its two outer end, a support structure comprising bearings for the rotating shaft, which support structure is connected to the base, and a pair of parallel oriented links connecting the excenters of the shaft to the moveable support and wherein the links are comprised of push pull rods and flex plates, wherein the push pull rods of the links are connected to the moveable support by means of an universal joint and wherein the flex plates are connected to the excenter by a 1DOF joint and wherein the movement simulator is provided with at least three actuators.

12. A movement simulator according to claim 11, wherein the actuator is an electric motor connected via a push pull rod to a driving crank positioned on the shaft of the torque device and wherein the driving crank is positioned between the two excenters of the rotating shaft and wherein the other end of the push pull rod is connected to an excenter on the rotating shaft of the electric motor.

13. A movement simulator according to claim 11, wherein the actuator is an electric motor provided with a rotating shaft and directly connected to the moveable platform by means of a push pull rod, wherein the push pull rod is connected at one end to an excenter or crank on the rotating shaft and at its other end to the moveable support via a joint.

Description

[0021] The invention will be illustrated using FIGS. 1-8.

[0022] FIG. 1 shows a movement simulator (1) according to the invention and FIG. 2 shows a cross-sectional view along the axis of rotation X of the shaft (5) of one of the actuators (4) of the movement simulator (1) of FIG. 1. The simulator (1) is provided with a moveable support (2) connected to a base (3) by means of three identical actuators (4). Each actuator (4) has a rotating shaft (5) having two outer ends (6,7). Two spaced apart supports (8,9) are shown at the end (6,7) of shaft (5). The support structures (8,9) are provided with double pre-loaded bearings (26,27) supporting the rotating shaft (5). At the two outer ends (6,7) of the shaft (5) a crank having the shape of an excenter (10,11) are present. Excenter (10) is aligned with excenter (11) having the same radius and angle with the shaft (5). Excenter (10) is connected to one link (12) and the other excenter (11) is connected to the other link (13). The links (12,13) are comprised of push pull rods (18, 19) and flex plates (17). The parallel oriented push pull rods (18, 19) of the links (12,13) are connected to the moveable support (2) by an universal joint (14,15). The flex plates (17) of the links (12,13) are connected to the excenter (10,11) by a 1DOF joint (16), using two preloaded bearings (16a). A part (5a) of the shaft (5) is shown between the two supports (8,9) and two parts (5b,5c) of the shaft (5) including the two ends (6,7) of the shaft (5) extend axially outwardly from the supports (8,9). In this Figure an electrical motor (21) is provided with a hollow shaft rotor (21). The rotor (22) of this motor (21) is fixed to part (5a) of the shaft (5) such that it rotates around axis (x) of rotation with the shaft (5). In this way the shaft (5) or at least a part of the shaft is in effect the rotor (22) of the electric motor (21). The stator (23) is connected to support (8). A non-load-bearing tube (24) added between both supports (8,9) covers the motor (21) and optional sensors.

[0023] FIG. 3 shows an alternative actuator (30) for the actuator (1) of FIGS. 1 and 2. The difference is that a bolted on crank (10) is connected to one link (12) by means of a ball joint (28) and a bolted on crank (11) is connected to the other link (13) by means of a ball joint (29). Such a configuration is referred to as an inverted ball joint. The links (12,13) are connected to the moveable support (2) by an universal joint (14,15). The ball of the ball joint is part of the link. The ball is received in a spherical liner which is part of the crank. The link (12,13) is provided with a curve such that a sufficient clearance is achieved between the link (12,13) and the crank (10,11). The advantage of such a design is that, in case the shaft is making full rotations, the moveable support (2) consequently makes large translations in its three degrees of freedom and the link can be shaped to prevent collisions within the systems full envelope of movement. Another advantage is that the axial distance between the shaft bearings (27) and the ball joint (29), and hence the bending loads in the shaft (5) are minimized

[0024] FIG. 4 is a three-dimensional view of the actuator (30) of FIG. 3 except that the tube (24) between the supports is not shown.

[0025] FIG. 5 shows an alternative actuator for the actuator (1) of FIGS. 1 and 2. A difference is that the electrical motor (21) is not positioned between the supports (8,9) as in FIG. 2 but in part (5b) of the shaft (5) as shown. In this figure also an excenter (32,33) is shown which is a machined end of the shaft (5). The flex plates (36, 37) of the links (12,13) are connected to these excenters (32,33) by means of a 1 degree of freedom joint (34, 35). The 1 degree of freedom joints (34, 35) are provided with bearings to provide the rotational degree of freedom relative to the excenters (32,33). An advantage of positioning the electric motor (21) at the exterior end of the shaft (5) is that the electrical motor can then be simply removed to be, for example, replaced of repaired without having to remove the shaft (5) from its supports (8,9).

[0026] FIG. 6 is a three dimensional view the actuator of FIG. 5.

[0027] FIG. 7 shows an alternative actuator for the actuator (31) as shown in FIGS. 5 and 6. The actuator is provided with a support structure (38) as comprised in one housing (39) in which two bearings (40,41) are present to support the shaft (5).

[0028] FIG. 8 shows a detail of an end (7) of a shaft (5) provided with a bolted-on crank (11). This figure illustrates the crank radius as radial distance (y) between the axis of rotation (x) of the shaft (5) and the joint centre (42) of the joint (43) connecting the crank (11) and the link (13).

[0029] It has been found that the use of a flex plate as described above may also be advantageous in movement simulator comprising of a moveable support and having three translational degrees of freedom provided with any type of actuator. This because the use of a flex plate simplifies the design by eliminating the use of a multiple degree of freedom connection to the crank. For this reason the invention is also directed to a movement simulator comprising of a moveable support having three translational degrees of freedom connected to a base by means of three torque devises comprising a rotating shaft having an excenter at its two outer end, a support structure comprising bearings for the rotating shaft, which support structure is connected to the base, and a pair of parallel oriented links connecting the excenters of the shaft to the moveable support and wherein the links are comprised of push pull rods and flex plates, wherein the push pull rods of the links are connected to the moveable support by means of an universal joint, a spherical joint or another flex plate or flex plates and wherein the flex plates are connected to the excenter by a 1DOF joint and wherein the movement simulator is provided with three actuators.

[0030] The torque devices may be as shown in FIGS. 1, 2, 5, 6, 7 and 8. Instead of the preferred electromotor (21) shown in these figures as the actuator another actuator may alternatively be used as described below. The three actuators may directly move the moveable support, for example by means of three linear actuators connected to the base and the moveable support as for example shown in Youtube video titled DTE 3-DOF Vibration System Running a Simulated Earthquake Test (https://www.youtube.com/watch?v=vLDGccz1PgU&t=2s). The actuators may also drive the shaft of the torque device as described in the aforementioned WO2013/050626 or as shown in Youtube video titled “Kollmorgen Cartridge DDR Motor used in Earthquake simulator built by ANCO Engineers” or according to the present invention.

[0031] The actuator may be an electric motor connected to the shaft of the torque device via a push pull rod. The electric motor is connected to the base. The push pull rod is connected at one end to an excenter or crank on the rotating shaft of the electric motor and at its other end to a driving crank positioned between the two excenters of the rotating shaft. The oscillating rotation of the rotor of the electric motor will result in an oscillating movement of the shaft and thus achieve the movement of the moveable platform in the three translational directions. Such an actuator is described in WO2013/050626.

[0032] The actuator may also be an electric motor connected to the shaft of the torque device via a push pull rod. The electric motor is connected to the base. The push pull rod is connected at one end to an excenter or crank on the rotating shaft of the electric motor and at its other end to the moveable support via a joint as described above. The oscillating rotation of the rotor of the electric motor will result in an oscillating movement of the platform in the three translational directions. The three rotating actuators directly move the moveable support.