GB2489529A

GB2489529A - Power transmission having a controller which activates a ferrofluid

Info

Publication number: GB2489529A
Application number: GB201105597A
Authority: GB
Inventors: Keith Anthony Coleman
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-04-02
Filing date: 2011-04-02
Publication date: 2012-10-03
Also published as: GB201105597D0

Abstract

A power transmission comprises a plurality of inner gears 2 with an inner flexible tubular cavity 3 filled with ferrofluid and the inner gears 2 have double helical inner and outer teeth 5, 6. A plurality of pinion gears 14 mesh with teeth of 5, 6 of the inner gears 2 and outer gears 7. A controller (11, fig 1) takes input from position sensors and monitors a current output of a traversing permanent magnet. The controller (11) controls a plurality of switches (27) to allow or block current to electromagnetic coils (12) which activates the ferrofluid so that it undergoes a density change and becomes weighted on a portion of inner gears 2 and causes a centre of gravity to shift. Any changes due to friction losses can be monitored and the ferrorfluid is activated accordingly so as to counter-balance abrupt inertia differences. A method of controlling the power transmission is also claimed.

Description

A MONITORING SYSTEM TO ASSIST A POWER TRANM1SSION MECHANISM

USING FERROFLUID

FIELD OF THE INVENTION

The present invention relates to monitoring and assisting a power transmission apparatus, especially dealing with disturbances caused by friction losscs and further relating to a method for maximizing power transmission torque.

BACKGROUND OF THE INVENTION

In the engineering field such as mechanical power transmissions or gearing mechanisms, huge power inefficiencies occur due to friction. Chinese Patent N20 1330824 Y with the title of "Device for transforming pendulum force to axial rotating force" discloses a utility model, which tries to remedy these inefficiencies using a uncontrolled swinging disc and ratchet wheel. Obviously, using this set up in the real world without a controller is not efficient because it doesn't take into account friction losses and doesn't adapt to abrupt changes. Furthermore, using two gyrator moveable pins adds to manufacturing costs of creating such an exotic model and its geometry is solely intended for small applications. This invention provides a low-cost, practical alternative that is monitored by a controller to readily adapt to disruptions in the real

SUMMARY OF THE INVENTION

One of the objects of the present invention is to provide a monitoring device that's assists in balancing disturbances with an optimized model caused by friction losses. A controller is provided that changes the center of gravity of the device with ferrofluid.

Another object of the present invention is to provide a method for maximizing inertial swings in a transmission mechanism to be used with an external component.

To achieve the above-mentioned first object, a power transmission apparatus (23) of the present invention comprises, a housing (1), a plurality of inner gears (2) with an inner flexible tubular cavity (3) filled with ferrofluid (4) and the inner gears having both double helical inner teeth (5) and outer teeth (6), outer gears (7) without ferrofluid (4) with both double helical inner teeth (8) and outer teeth (9), a plurality of pinion gears (14) with double helical teeth (17) meshing with the double helical teeth (5 and 6) of the inner and outer gears (2 and 7), a shaft (15) traversing the pinion gears (14), a plurality of bearings (16) for all gears (2, 7, and 14),a position sensor (10) for both inner gears (2) and outer gears (7), a controller (ii), energy storage device (18), a plurality of permanent magnets (19) for each outer gear (7), a plurality of electromagnetic coils (12) for each inner gear (2) and coils (13) for each outer gear (7), a plurality of switches (27) configured to energize/dc-energize the plurality of electromagnetic coils (12) and coils (13).

To control the power transmission apparatus, a method is provided to comprise the steps of: Monitoring the current (c) caused by the permanent magnets traversing through the coils outside the outer gears; Using the current (c) caused by the swinging permanent magnet through the coils to calculate the speed (s); Comparing the initial position (Pininaipermenantmagnet) of the permanent magnet with the current produced to calculate the final position (PfiflapermentmagneJ; Subtracting out losses due to friction from final position (Pfjnap&tnenantag); Matching the final position (Pfina1permenan1mant) with the corresponding position of electromagnetic coils (Pinitiaiciectromagnct) parallel to the position of the permanent magnet; Choosing an adjusted position (APinitiaieiectromagnet) that is higher or lower that is dependent upon (Pflnalpertncnantinagnet); Energizing the corresponding electromagnetic coils to increase the density of the ferrofluid in that part of the cavity inside the inner gear to create an inertial difference; Driving the shafts of the power transmission apparatus via the pinion gears in an opposite direction due to the new inertial change caused by the inner gears and gravity; Rotating a component connected to a one-way clutch via the driving shaft; Dc-Energizing the coils by a plurality of switches once the permanent magnets has changed direction and allowing the swelling to return to its original state in the inner gears; Repeating the same steps in the new direction.

Because of the density change caused by the electromagnetic coils, the power transmission apparatus becomes weighted on a portion of the inner gears and causes the center of gravity to shift. Any changes due to friction losses can be monitored and the apparatus can be adjusted accordingly to counter-balance the abrupt inertia differences.

Furthermore, the method can be used to drive other components such as a small generator (20) or turbine (21) with a one-way clutch (22), which the total output of the device would depend on the weight of the permanent magnet, the diameter of the outer and inner gears, the number of coils traversed by the permanent magnet, the power needed for the switches, and the number loops of each coils.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a power transmission apparatus in accordance with a preferred embodiment of the present invention; FIG. 2 is a perspective view of the power transmission apparatus of F1G. 1 disclosing the outer gear with the permanent magnets and coils; FiG. 3 is a perspective view of the power transmission apparatus of FiG. 1 disclosing the inner gear with the ferrofluid and electromagnetic coils; FiG. 4 is a perspective view of the shaft member and pinion gear as seen in FiG. 1;

HG. 5 is a perspective view of a component connected to the preferred embodiment in FIG. 1.

DETAiLED DESCRiPTION OF THE PREFERRED EMBODiMENT

FIG. 1-5 illustrate one preferred embodiment of the present invention, illustrated as power transmission apparatus 23. The power transmission apparatus 23 comprises a housing 1 with both outer gears and inner gears having double helical teeth. The plurality of inner gears 2 have an inner flexible cavity 3 filled with ferrofluid 4 to change the center gravity caused by an increase in ferrofluid density.

The outer gears 7 are preferably without ferrofluid 4 and have both double helical inner 8 and outer teeth 9 that mesh with plurality of pinion gears 14.

A plurality of shafts 15 traverse the pinion gears 14 and through the helical gears keeps the outer and inner gears in place as shown in Figure 1. To reduce friction losses, a plurality of bearings 16 are used for all gears 2, 7, and 14 and the ends of the shafts embedded in the housing.

The controller 11 takes input from a plurality of position sensors 10 located on the outside or inside of gears 2 and 7 and monitors the current output of the traversing permanent magnet. The controller also controls the plurality of switches 27 to allow or block current flow to the electromagnetic coils 12. if the current output doesn't match the output position, the power transmission apparatus can be reset manually by rotating the shafts by hand or automatically by the controller via inducing current into the outside coils 13 and setting the switches 27 in the off position. As discussed previously, the controller II can monitor the current output through an energy storage device 18 and the controller can be powered by the same 18 or different externally charged energy storage devices 24. Furthermore, additional parameters corresponding to the output of a small generator 20 or the speed of a turbine 2! with a one-way clutch 22 will be monitored to optimize the plurality of shafts output and torque.

Other configurations may be used to monitor the power transmission apparatus's direction and speed. Depending on the output needed to actuate the switching mechanisms, the apparatus may need more than one external energy source.

The present invention is not intended to be limited to the above-mentioned embodiment. It is easily understood for those ordinary skilled in the art that there are various modifications or alternatives without departing the conception and principle of the present invention. The scope of the present invention is defined by the appended claims.