NO20161501A1

NO20161501A1 - Power-assisted operating mechanism for sliding doors

Info

Publication number: NO20161501A1
Application number: NO20161501A
Authority: NO
Inventors: Baard Nilsen
Original assignee: Ims Group As
Priority date: 2016-09-20
Filing date: 2016-09-20
Publication date: 2018-03-21
Also published as: WO2018056830A3; WO2018056830A2; WO2018056830A4

Abstract

An operating mechanism for a sliding door is disclosed. The sliding door is linearly actuated by a low-friction spindle/nut arrangement wherein a single, transmission-free, high-torque electrical motor comprising alternative stator windings for redundancy is arranged to drive said nut.An operating mechanism for a sliding door is disclosed. The sliding door is linearly actuated by a low-friction spindle/nut arrangement wherein a single, transmission-free, high-torque electrical motor comprising alternative stator windings for redundancy is arranged to drive said nut.

Description

Field

The present invention relates to means for operating sliding doors. More specifically, the invention relates to power-assisted, compact and redundant means to close and open heavy sliding doors.

Background

Watertight doors - or other heavy sliding doors - have traditionally been operated electrically or hydraulically. In hydraulically operated doors, a hydraulic cylinder is used to transfer the opening/closing force to the door leaf. Electric doors have opening/closing force transferred with a spindle (threaded rod, “screw”) or a gear rack (rack and pinion). Electrically operated doors are now preferred in many marine projects because it eliminates the hydraulic system and this entails cost benefits. The closing speed is relatively low and the doors close at between 20 and 40 seconds.

Opening speed is not specified in the regulations.

Conventional electrical motors operate at high rotational speeds and relatively low torques. It is therefore necessary to have a torque conversion in terms of mechanical transmissions and/or chain transfers to obtain suitable RPM and sufficient torque.

Watertight doors must be operable manually, i.e. by hand. The generated power that can be used to close the door is therefore limited. The closing time for the doors by manual operation is specified in regulatory requirements and must be within 90 seconds.

To achieve a redundant solution with electrically operated doors, two motors are needed. For a system with two individual motors to be redundant, they must either be connected with a differential gear or a gear/clutch solution. This is a system with many mechanical components and many sources to mechanical failure and also increases the noise level in operation.

Therefore, there exists a need for an improvement of the present state of the art in this field, to which the present invention will contribute.

Summary

This patent specification discloses an operating mechanism for sliding doors being linearly actuated by a low-friction spindle/nut arrangement. A single, transmission-free, direct-drive, high-torque electrical motor comprising at least 2 alternative stator windings for redundancy is arranged to drive the nut.

The spindle of said operating mechanism can be non-rotatably mounted inside the door leaf of the sliding door and the electrical motor contains said nut coaxially in its rotor.

A manually operable electrical generator as a part of the operating mechanism can in case of a power failure supply power to the electrical motor.

The operating mechanism can be used for a watertight bulkhead sliding door for marine applications.

Brief description of the drawings

Below the preferred embodiments of the invention will be described with reference to the attached drawing where

fig. 1 is an overview of a door and door frame showing spindle and motor, the motor being mounted to the wall,

fig. 2 is an overview of the inventive embodiment with a spindle penetrating a motor as a ‘virtual’ motor shaft, the spindle being mounted inside the door leaf,

fig. 3 shows a cross section of spindle and motor with coaxial nut, and

fig. 4 shows a cross section of spindle, motor and nut as used in fig. 1.

Detailed description

Fig. 1 shows a simplified version of the inventive slide door operation mechanism: a motor 5 mounted with a bracket 12 to a wall adjacent to the door frame 2 turns a spindle 4 passing through a nut 6 which is non-rotatably mounted to the door leaf 1. The rotating spindle 4 moves the door leaf by way of the nut 6. The door frame 2 holds the operating interface - a selector handle for opening, closing or idle/off and a crank handle for manually rotating an emergency generator 3 to provide power in case the externally supplied power fails.

Fig 2 gives a detailed view on another embodiment of the inventive sliding door. A spindle 4 is non-rotatable mounted horizontally in parallel to the moving direction of the door leaf 1 between the side panels of the door leaf. Threaded onto the spindle 4 is an electrical motor 5 which holds å low-friction nut 6 in the center of its rotational axis. Even the spindle 4 penetrates the motor 5 coaxially, it is actually not the motor shaft, but the nut 6 is. The motor 5 is also fixed (rotationally and laterally) to the door frame 2 in order to be able to exert a force onto the spindle 4 and thus the movable door leaf 1. As in fig. 1, the door frame 2 holds the operating interface as described above.

The door leaf 1 is necessarily at least partially open on the side being directed to the wall in order to slide and at the same time having the motor 5 fixed to the frame/wall 2. However, fig. 2 shows the door leaf without the water-tight panel on the opposite side in order to make motor 5 and spindle 4 visible to the viewer of fig. 2.

When power is supplied to the motor 5, a torque is generated onto the motor axis and thus the nut 6. A counter torque tries to rotate the motor 5 in opposite direction, which however is inhibited by the fixation to the door frame 2. This makes the nut 6 rotate and this in turn moves the spindle 4 - also mounted non-rotatable - which carries the door leaf 1 with it. By changing the rotating direction of the motor 5, the door leaf 1 can be opened or closed.

Fig. 3 shows a cross section of motor 5 and spindle 4. The spindle penetrates the motor 5 through the nut 6. The nut is part of the rotational shaft of the motor 5 and is connected to the motor housing 1 1 holding the stator windings 8, 9 by bearings 7.

Fig. 4 shows a cross section of motor 5 and spindle 4 as used in fig. 1 where the nut 6 is NOT located inside the motor 5. Instead, the nut 6 is mounted non-rotatably to door leaf 1 and the spindle 4 is non-rotatably mounted to the shaft of the motor 5. When the motor rotates, it rotates the spindle 4 which translates the rotation to a lateral force on the door leaf 1 by use of the non-rotatably mounted nut.

In all embodiments described above, preferably the spindle/nut combination 4, 6 is a low-friction arrangement, for inst. a so-called ball nut on a corresponding type of spindle, (https://en.wikipedia.org/wiki/Ball screw , viewed on 2016.09.13). Figs. 3 and 4 indicate no balls at the interface between nut and spindle (the indicated balls are parts of the bearings 7), thus showing a conventional nut/spindle mechanism which relies on lubrication only to avoid friction.

Reference numerals

1 Door leaf

2 Door frame

3 Manual generator 4 Low friction spindle 5 Direct drive motor 6 Nut

7 Frame bearings

8 Rotor

9 Stator winding

10 Stator winding

11 Motor housing

12 Motor bracket

Claims

Patent claims

1 An operating mechanism for a sliding door being linearly actuated by a lowfriction spindle (4)/nut (6) arrangement characterized in that a single, transmissionfree, high-torque electrical motor (5) comprising alternative stator windings (8, 9) for redundancy is arranged to drive said nut (6).

2 Operating mechanism according to claim 1, wherein said spindle (4) is non-rotatable mounted inside a door leaf (1) of said sliding door and said electrical motor (5) contains said nut (6) coaxially in its rotor (8).

3 Operating mechanism according to claim 1, wherein a manually operable electrical generator (3) in case of a power failure is arranged to supply power to said electrical motor (11).

4 Operating mechanism according to claim 1, wherein said sliding door is a watertight bulkhead door for marine applications.