HYDRAULIC DIFFERENTIAL IN AN ELECTRICAL MOTOR

Abstract: The device consists of two hydraulic pumps/motors with adjustable displacement (1 and 2) connected in a closed hydraulic system. The system includes oil accumulators on each side of the hydraulic pumps/motors with adjustable displacement. There are 'pumps', valves and check valves to compensate for leakage of oil. In the system there is a valve (8) to change the inlet and outlet of the hydraulic pumps/motors with adjustable displacement. The hydraulic pumps/motors with adjustable displacement are 'flanged' to the rotor of an electrical motor in such a way that their shafts (3 and 4) are the 'shaft' of the rotor (6). The device forms within the rotor of an electrical motor a power unit (device), which consists of an electrical motor, a differential and facilities for changing the direction of rotation of the shafts. The device can be used for instance by a vehicle.

Description: HYDRAULIC DIFFERENTIAL IN AN ELECTRICAL MOTOR The field of applications for the invention is as powerunit( evice) in i.e vehicles.The device uses the technic of a pair of hydraulic pumps/motors with adjustable displacemen ,fluidly connected in a closed system with a valve (solenoid directional controls), nd two accumulators within a rotor in an electrical motor where the valve will be able to change the inlet and outlet of of the two hydraulic pumps/motors with adjustable displacement.Accumulators and check valves are used to compensate for the leakacre of oil within the system. what one achieve when one compare the state of the art today is: -In a vehicle it creates a very favorable concentrated centre of gravity and by that less total weight and cost -Together with a transmission of drive belts(cogged) it enables a high efficiency in comparison with a conventionel mechanical transmission -The manoevrebilaty will be good because the two shafts of the rotor may rotate at different εpeed and direction -As an electrical gauge it can indicate relative movement between the two shafts.The rotational speed had to be compared with a reference rotational speed at one shaft The device includes a pair of hydraulic pumps/motors with adjustable displacement which are fluidly and mechanically connected.When.they have the same torque on the shafts they act as one rigid shaft.The rigid shaft iε the 'shaft' of the rotor of an electrical motor.The hydraulic system is totaly internal within the rotor.By practical reasons there will be a valve(solenoid directional controls) ,check valves and accumulators in the system.There is a valve in the system which makes it possible to change the fluid flow in the system. hat makes it possible to get different rotational εpeed and even different direction of the rotation.A further explanation to the invention will be below by referring to the accompanying drawings wherein: Fig.l ilustrates schematically the 'shaft' in the rotor of the powerunit(device) . Fig.2 ilustrates the fluidchart out of functional symbols Fig.3 ilustrates an eκempel of application in an electrical forklift-truck or autocarrier. Each of the hydraulic pumps/motors with adjustable displacement (1) and (2) ,the accumulators (6) and (7) and the valve,solenoid directional controls, (8) are fluidly connected in a closed hydraulic system within the rotor (5) of an electrical motor.The hydraulic pumps/motors with adjustable displacement are 'flanged' to the rotor.When the torque iε equal of the two different shafts of the rotor the hydraulic pumps/motorε with adjustable displacement pump towards each other with equal preassure.That the torque of the rotor is transformed,equal, (0,5) to the different εhaftε (3) and (4) of the two hydraulic pumps/motors with adjustable displacement,compare the conventional differential.If the torque iε greater in one end of the 'shaft' of the rotor (M2) than the other end of the 'shaft' of the rotor (Ml) the torque of the rotor will pump the fluid from the 3 . hydraulic pump/motor with adjustable displacement ' (2) to the other hydraulic pump/motor with adjustable displacement (1) ,for instance 25 litres/min if the right one stands still (4).The hydraulic pump/motor (1) with adjustable displacement will rotate shaft (3) in the same relative rotation backwards per revolution of the rotor aε the hydraulic pump/motor with adjustable displacement rotatates relative the rotor forwards. ith one shaft 'locked' the other will rotate at the double speed of rotation of the rotor.Persu e the torque of the motor=Mm and angualar velocity=wm. Mm*wm=Ml*wm+M2*wm and if wm=0 for for the shaft with M2 Mm=2*Ml*wm If one change the direction of the flow of the fluid and a flow is created by means of 'slipring' one of the two hydraulic pumps/motors with adjuεtable diεplace ent and the adjuεtable diεplacement is smaller for the other hydraulic pump/motor with adjustable displacement,the later one will rotate backwards relative the rotor.To be able to in a simple way control the valve,and the adjustable displacement of the hydraulic pumps/motors the shafts of the driving device will be electrically insulated from each other.That means they can be electrically controlled by different polarity of voltage at different end of the shafts of the powerunit( " device) . The centre-line of the slide of the valve (solenoid directional controls) shall be in line or parallel with the centre-line of the rotor to avoid unbalance when altering the slide into different positions.To manoevre the flow in the hydaulic pumps/motors with adjustable- displacement one use an electrical linear ' actuators',a servo or small electrical motors where the electrical power are turned off at the end of the movement

Claims: I claim as new : l.A hydraulic differential within an electrical motor characterizid by Two hydraulic pumps/motors with adjustable displacement are mechanically connected by their housing to the rotor within the stator of an electrical motor and fluidly connected in such a way that if one lock the rotor to a fixed position and rotate the shaft of one of the hydraulic pumps/motors with adjustabl displacement the other hydraulic pump/motor with adjustable displacement rotateε in the opoεite direction and there is a valve in the system in εuch a way that if one change the direction of the flow to the other hydraulic pump/motor with adjuεtable displacement and the capacity per revolution is adjustable different rotation speed and direction of rotation of the shafts will be achieved. 2.A device according to claim 1 characterized by In the hydraulic system there are oil accumalators separated by the hydraulic pump/motor with adjustable displacement to make an elastic start possible of the rotation of the shafts. 3.A device according to claim 1 characterized by There are two pumps,valves and checkvalves in the hydraulic system to compensate for leakage of oil 4.A device according to claim 1 characterized by There are accumulators and checkvalves in the hydraulic system to compensate for leakage of oil 5.A device according to claim 1 characterized by The two hydraulic pumps/motors with adjustable displacement are electrically insulated from each other in such a way that controlling the direction of the flow within the rotor is possible and to adjust the displacement of the hydraulic pumps/motors by means of different electric polarity on the shafts and electrically controlled at the end of the movement by the way that the power is turned off 6.A device according to claim 1 characterized by The valve for changing the direction of the flow has its centre-line situated in line or parallel with the axle of the rotor in such a way that no unbalance will appaer when one change the direction of the flow.

Inventors: THORELL CHRISTER, THORELL, CHRISTER
Applicants: THORELL CHRISTER, THORELL, CHRISTER
Application year: 1991
Main classification: F16H39
IPC codes: B60K17, F16H39