External load testing device

Abstract

The external load testing equipment includes: - a structure having at least three pillars (2) supporting a platform (3) configured to receive a podded electric propulsion motor (4) in a suspended position while allowing operation of the pod; - at least one test subsystem (5a, 5b) for applying forces to the pod to simulate a full-scale external load.

Description

Technical Field

[0001] This invention relates to a full-size test rig (or test equipment), particularly a test rig for conducting external load tests (especially ice load tests) on ship propeller pods. Background Technology

[0002] Thrust vectoring is becoming increasingly common to improve the steering of large ships. This vectoring allows the main propeller to be used for lateral or counter-lateral motion. To achieve this vectoring, the main propeller is mounted on a pod, which allows the transmission of engine power while permitting the propeller to rotate in either direction.

[0003] Strict regulations require that such pods be able to withstand the pressure of ice that may be encountered in the Arctic Ocean.

[0004] To date, compliance with these regulations has been achieved by combining design safety margins with scaled-down prototype testing within a statistical approach. Such testing is commonly referred to as ice load testing.

[0005] However, customers now typically require compliance guarantees for each pod. Therefore, individual testing of each pod is required. Testing is also mandated before assembly to prevent damage to the vessel.

[0006] Based on existing technology, the following documents are known.

[0007] Document WO2019-011927A1 discloses a method for determining the direction and magnitude of forces applied to a propulsion nacelle, including stress direction identification.

[0008] Document CN103913291 discloses a test device for a podded propulsion system, which includes devices for measuring the torque and thrust generated by the podded propulsion system.

[0009] There is no test bench capable of performing full-scale external load tests on propeller pods. Summary of the Invention

[0010] The object of the present invention is an external load testing device comprising: a structure having at least three supports, a support platform configured to receive a podded electric propulsion motor in a suspended position while allowing operation of the pod; and at least a testing subsystem for applying forces to the pod to simulate a full-scale external load.

[0011] The test subsystem may include a pod actuator interface, an actuator, and an actuator structure interface. The actuator structure interface includes a frame and devices designed to be removably fixed to the structure. The devices form a rotary joint with the actuator, such that the actuator is anchored to the structure while maintaining at least one degree of rotation. The actuator includes an actuator body and an actuator rod, which is configured such that the actuator rod extends from or retracts into the actuator body upon command.

[0012] The pod actuator interface may include a drilled hole on one side for mating with the pod output shaft, and an actuator rotary joint for the actuator rod on the opposite side.

[0013] The torque measuring device can be mounted on the test subsystem. The torque measuring device includes two links that connect the pod actuator interface to the structure and force sensors attached to each link. The torque is determined based on the force being measured, the size of the link, and the size of the test equipment.

[0014] This force can be applied in a direction different from the direction of the pod's output shaft.

[0015] The pod actuator interface may include a plate on one side, which is fitted with a pod shape compensation element that contacts the pod, and a rotary joint with the actuator rod on the opposite side.

[0016] The actuator structure interface may include a frame or beam for removably securing the test subsystem to the structure.

[0017] The test subsystem can apply force in a direction that is reasonably matched with the direction of the pod's output shaft.

[0018] The test subsystem can apply force in the vertical direction.

[0019] The actuator for the test subsystem can be a hydraulic jack, a magnetic actuator, or an Archimedes screw.

[0020] The pod can be rotatably fixed to the platform, and the rotation of the pod helps to apply force in different directions.

[0021] The test subsystem can be removably fixed to the structure.

[0022] The test equipment may include a command device for commanding the pod, at least one actuator, and (if applicable) a force sensor to rotate.

[0023] Command devices are capable of executing continuous, variable, or cyclic external loads.

[0024] This testing equipment can be used for ice load testing. Attached Figure Description

[0025] The invention will be better understood from the study of various embodiments, which are described in a completely non-limiting manner and by way of detailed description of the accompanying drawings, in which:

[0026] - Figure 1 An embodiment of the external load testing equipment is shown.

[0027] - Figure 2 An axial testing subsystem is shown.

[0028] - Figure 3 The lateral testing subsystem is shown, and

[0029] - Figure 4 An axial testing subsystem equipped with a torque measurement system is shown. Detailed Implementation

[0030] Ice load testing is a special case of external load testing, in which an external load is applied to a podded electric propulsion motor.

[0031] The external load testing equipment described in this paper exhibits the advantage of being self-supporting because it does not require complex civil engineering work before operation. It also does not require the civil engineering work to be resilient to the reaction forces involved in the test.

[0032] The external load testing equipment includes a structure with at least three struts supporting a platform that receives a podded electric propulsion motor (“pod”) and provides the auxiliary systems required to operate the pod, particularly hydraulic and electric power. Figure 1 The illustration shows a specific embodiment of an external load testing device 1 with four pillars 2.

[0033] More specifically, platform 3 includes a collar that mates with a complementary collar on pod 4, allowing for the securing and rotation of the pod. At least one of the collars includes a bearing that allows for sustained rotational capability. The mating can be achieved via bolted connections. Once secured to the platform, the propeller pod is suspended below the platform in a manner similar to its mounting on a ship. This arrangement is considered standard practice for mounting pods on the hull of a ship and is therefore not described further.

[0034] Structures 2 and 3 can be equipped with different subsystems 5a and 5b for external load testing, particularly the axial test subsystem 5a and / or the lateral test subsystem 5b. Due to the collar and auxiliary systems, the pod can operate and rotate as it would on a ship. The rotation of the pod, combined with the placement of the different test subsystems 5a and 5b, allows for external load testing of the pod in different directions. External loads can also be applied to the pod's propeller.

[0035] Figure 2The axial test subsystem 5a is illustrated as an exploded diagram. It includes a pod actuator interface 6a, an actuator 7a, and an actuator structure interface 8a.

[0036] The pod actuator interface 6a is mounted on the pod output shaft, on which the propeller is designated for mounting. On one side, the pod actuator interface 6a therefore includes a drilled hole similar to that present on the propeller, allowing the pod actuator interface to be fastened to the pod shaft. On the opposite side, the pod shaft actuator interface 6a includes a rotary joint with the actuator. Figure 2 In the rotary joint, there are two pin holes 61a, which are designed to cooperate with the corresponding drill holes 70a and pins 60a that enter the actuator rod.

[0037] Actuator 7a includes actuator body 71a and actuator rod 72a, which extends or retracts from actuator body according to command. The actuator includes a bore 70a located at the free end of the actuator rod and two gudgeons 73a located away from actuator body 71a. The distance between the bore and the gudgeons increases as the actuator extends. The gudgeons are part of a second rotary joint that interfaces with actuator structure 8a. External load testing equipment is not limited to, for example... Figure 2 The trunnion connector is used in the second rotary connector as shown in the diagram.

[0038] The actuator structure interface 8a enables the actuator body 71a to be anchored to the external load test equipment structures 2 and 3, so that a force is generated on the pod output shaft when the actuator rod is extending.

[0039] For this purpose, the actuator structural interface 8a includes a frame 80a designed for removable attachment to structures 2 and 3, and two semi-cylinders 81a connected to the frame via support members 82a. The semi-cylinders and two pins on the actuator body form trunnion bearings (or trunnion joints). Other forms of rotary joints can be used to replace the trunnion bearings. Due to the trunnion joints, the actuator is capable of rotating about an axis extending through the pins and semi-cylinders. This rotation allows the axial testing subsystem to accommodate different angles between the pod output shaft and the platform.

[0040] In a particular embodiment, the structure includes multiple anchor points for the actuator structure interface, allowing it to be mounted at different distances relative to the platform. This enables the test subsystem to accommodate pods of different sizes.

[0041] Figure 3 The diagram shows an exploded view of the lateral testing subsystem 5b. The lateral testing subsystem includes the pod actuator interface 6b, the actuator 7b, and the structural actuator interface 8b, and is therefore similar to the axial ice load subsystem 5a.

[0042] On one side, the pod actuator interface includes two pin holes 60b, which are designed to engage with corresponding drill holes 70b and pins 61b entering the actuator end. This arrangement allows for securing the connection between the pod actuator interface and the actuator while allowing for a degree of rotation. As previously described, this arrangement is an example of a rotary joint that can be used in a test subsystem. Other rotary joints may also be considered, provided they can withstand the relevant forces.

[0043] The opposite side of the pod actuator interface includes a plate 62b and a pod shape compensation element 63b stacked above the plate, such that the actuator applies a force to the plate, the plate applies a force to the pod shape compensation element, and the pod shape compensation element in turn applies a force to the pod shell. Depending on the shape of the pod shell, the pod shape compensation element 63b can have a complex shape to match both the shape of the shell and the orientation of the plate. It can also be made of a compressible or deformable material, so that its shape can be changed under pressure to match the shape of the shell.

[0044] Actuator 7b includes actuator body 71b and actuator rod 72b, which extends or retracts from actuator body 71b upon command. Actuator 7b includes a bore 70b located at the free end of actuator rod and two pins 73b away from actuator body. When the actuator is extending, the distance between the bore and the pins increases.

[0045] The actuator structure interface 8b includes a frame 80b designed for removable attachment to the structure and two semi-cylinders 81b connected to the frame via support members. The semi-cylinders and the actuator's two pins form trunnion bearings. A rotary joint, different from the trunnion bearings, may be considered.

[0046] Depending on the number and placement of the structural supports 2, the actuator structural interface 8b includes a beam 83b, which acts as an arm connecting the frame 80b to the support member 82b. In a particular embodiment, the beam 83b is removably fixed to the frame 80b, allowing the distance between the actuator and the platform 2 to be adjusted. This enables the lateral testing subsystem to accommodate pods of different sizes.

[0047] In a particular embodiment, the actuator includes a second pair of pins 74b, each pin being located away from the actuator body, and the actuator structural interface includes a second pair of hemi-pillars 85b. In such an embodiment, two trunnion bearings are thus formed between the actuator 7b and the actuator structural interface 8b, thereby locking the angle of the actuator relative to the platform. In yet another embodiment, the actuator structural interface includes a plurality of first pairs of hemi-pillars and / or a plurality of second pairs of hemi-pillars, such that each pair of actuator pins can engage two pairs of hemi-pillars located at different distances relative to the platform. This arrangement allows different angles between the platform and the actuator to be achieved using a single lateral testing subsystem based on the spacing between the pairs of pins and the distance between the pairs of hemi-pillars.

[0048] Each test subsystem can be equipped with a torque measurement system comprising two rigid links extending between the pod actuator interface and the structure. At least a force sensor (such as a strain gauge or deformation gauge) is attached to each link, preferably at equidistant points at the ends of the links. The torque can then be determined based on the dimensions of the links, the pod actuator interface, and the structure, as well as the measured forces. Figure 4 The diagram shows an axial test subsystem equipped with a torque measurement system, which includes two rigid connecting rods 90a and 91a.

[0049] Another embodiment of the test subsystem is connected to the structure such that the actuator is positioned below the pod to apply forces reasonably vertically. In such an embodiment, the frame preferably serves as the interface for the structural actuator.

[0050] The embodiments described above relate to using actuators to apply pressure to a pod. However, different actuators can be used, particularly hydraulic, magnetic, or mechanical actuators. An example of a hydraulic actuator is a jack. An example of a mechanical actuator involves using a ring screw or Archimedes screw to apply force to a pod jack interface.

[0051] The external load testing equipment includes a command system for commanding the pod, actuators, and (if applicable) force sensors to rotate. It allows for open-loop or closed-loop operation of the external load testing equipment. Operation can be supervised or autonomous. Continuous, variable, or cyclic external loads can be applied.

[0052] External load testing equipment allows for the application of a wide range of forces, from a few N to a few MN.

[0053] The external load testing equipment described above does not require complex civil engineering work because it is self-supporting. However, in some embodiments, the vertical testing subsystem may be anchored to the civil engineering work below the external load testing equipment, rather than being fixed to the structure.

[0054] Finally, when multiple test subsystems are included, the external load test equipment can simultaneously combine forces applied to the pod and / or its propeller in multiple directions for more complex test scenarios.

Claims

1. An external load testing device, comprising: - A structure having at least three pillars (2) supporting a platform (3), the platform being configured to receive a podded electric propulsion motor (4) in a suspended position, while allowing operation of the pod. - At least test subsystems (5a, 5b) to apply forces to the pod or pod propeller to simulate full-scale external loads; The test subsystem (5a, 5b) includes a pod actuator interface (6a, 6b), an actuator (7a, 7b), and an actuator structure interface (8a, 8b). The actuator structure interface (8a, 8b) includes a frame and devices designed to be removably fixed to the structure. The devices form a rotary joint with the actuator (7a, 7b) such that the actuator (7a, 7b) is anchored to the structure while maintaining at least one degree of rotation. The actuator (7a, 7b) includes an actuator body (71a, 71b) and an actuator rod (72a, 72b). The actuator rod (72a, 72b) is configured such that it extends from or retracts into the actuator body (71a, 71b) upon command. The pod actuator interface (6a, 6b) includes a drilled hole on one side for engaging with the pod output shaft, and an actuator rotary joint on the opposite side for engaging with the actuator rod. The torque measuring device is mounted on the test subsystem and includes two links and a force sensor attached to each link. The two links connect the pod actuator interface (6a, 6b) to the structure. The torque is determined based on the force being measured, the dimensions of the links, and the dimensions of the test equipment.

2. The external load testing device according to claim 1, wherein, The force is applied in a direction different from the direction of the pod's output shaft.

3. The external load testing device according to claim 1, wherein, The pod actuator interface (6a, 6b) includes a plate on one side, the plate being fitted with a pod shape compensation element that contacts the pod, and a rotary joint with the actuator rod on the opposite side.

4. The external load testing device according to any one of claims 1 to 3, wherein, The actuator structure interface (8a, 8b) includes a frame or beam for removably securing the test subsystem to the structure.

5. The external load testing device according to any one of claims 1 to 3, wherein, The test subsystem applies the force in a direction that is reasonably matched with the direction of the pod's output shaft.

6. The external load testing device according to any one of claims 1 to 3, wherein, The test subsystem applies the force in the vertical direction.

7. The external load testing device according to any one of claims 1 to 3, wherein, The actuator of the test subsystem is a hydraulic jack, a magnetic actuator, or an Archimedes screw.

8. The external load testing device according to any one of claims 1 to 3, wherein, The pod is rotatably fixed to the platform, and the rotation of the pod helps to apply the force in different directions.

9. The external load testing device according to any one of claims 1 to 3, wherein, The test subsystem is removably fixed to the structure.

10. The external load testing device according to any one of claims 1 to 3, comprising a command device for commanding the pod, the at least one actuator (7a, 7b), and, if applicable, the force sensor to rotate.

11. The external load testing device according to claim 10, wherein, The command device is capable of executing continuous, variable, or cyclic external loads.

12. The external load testing device according to any one of claims 1 to 3, wherein, The testing equipment was used for ice load testing.

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