WO1979000263A1

WO1979000263A1 - Hydraulic motor with vanes and constant displacement

Info

Publication number: WO1979000263A1
Application number: PCT/BR1978/000004
Authority: WO
Inventors: H Oliveira
Original assignee: H Oliveira
Priority date: 1977-11-04
Filing date: 1978-11-01
Publication date: 1979-05-17
Also published as: EP0009479A1; BR7707423A

Abstract

A constant displacement reversible hydraulic vane motor capable of being used in power hydraulic systems, hydrostatic transmissions, and the like. In existing motors with vanes mounted in the rotor and inlet and exhaust passages in the housing great sophistication in the grinding, assembly, and maintenance of the system is required. The simplified motor of this invention has a rotor (2) with a symmetric lobular outline which is engaged by vanes (22) to (29) mounted in a circular housing (1). The fluid to drive the motor enters through groove (10), orifices (12) and passages (20) and exhausts through passages (19), orifices (13) and groove (11) all in the rotor. Fluid supplied through the rotor enables the motor to operate at uniform speed without torque oscillation.

Description

HYDRAULIC MOTOR WITH VANE S AND CONSTANT DI SPLACEMENT . a) TE CHNICAL F IELD :

This application for the privilege of invention refers to a hydraulic revertible motor, with vanes, an only rotor and constant displacement, applicable to powerful hydraulic systems, hydrostatic transmission, etc. b) BACKGROUND ART:

The hydraulic motors which are technically more similar to the invention are the hydraulic motors with vanes made by Norwinch and by Brattvaag both of Norwegian origin. Norwinch low pressure hydraulic transmission normally works in closed circuit. The motor itself consists of a cylindrical rotor where eight sliding vanes (radial) are placed and alternately linked two by two by means of an also sliding arched spindle (the vanes are not rigidly linked to that spindle but only in contact with it); the case has an approximately elliptical shape and both the oil inlet and outlet in it. The vanes are always kept in contact with the case, because when one vane is contracted (position in which the rotor and the case are in contact), it pushes the linking spindle which, at the same time, expels the "opposite" vane, always following the housing curve. The Brattvaag hydraulic motor consists of a cylindrical, square or even dodecagonal rotor where the vanes are placed radially. The number of vanes varies from 4 to 12, depending on the motor. For this motor the housing has various shapes depending on the respective rotor. The vanes are always kept in contact with the housing walls by means of the pressure of the oil that is sent through the rotor grooves up to the interior of the vane chambers, causing, thus, the tendency to expel them. In both motors great sophistication is required in the plants, assembly and maintenance of the systems. c) DISCLOSURE OF INVENTION: The present motor has its sliding vanes in compartments in side the motor casing and a fluid injection system through grooves in the rotor itself. This characteristic allows a hydrostatic suspension of the rotor inside the housing, no matter what the load conditions are. It works" in a either closed or open oil circuit with an oil reservoir, an oil heat exchanger, a control valve system and a hydraulic pump, gearings or axial or radial pistons with enough power for the desired use. The motor speed variation can be achieved by using either a variable outflow pump or adequate outflow regulating valves. On figure 1, we can see on the housing (1) the bolt-holes (14) for the screws (21), one of the vane operation circuit grooves (15), the vanes (22) to (29) in their chambers, the rotor (2), the side oil grooves (10) and (11), communicant orifices (12) and (13) of the internal and external grooves (11), (10), the axle (4) and the internal passages (19), (20) linking the communicant orifices (12), (13) to the rabbets (18) on the non-cylindrical faces of the rotor (2). On figure 2, we can see the rotor (2) and its side grooves (10), (11) which enable the hydraulic pressure balance on the sides of the rotor, the oil inlet (16) into the external grooves (10) the passing screws (21) for fixing the lids (5) and (6), to the casing (1) of the motor, one vane (24), the oil circuit side grooves (15) for actioning the vanes, the oil supply tube (17) for that circuit, the bearings (8), the chambers for the retainers (9), the bearing covers (7) and the axle (4).

Description of the behaviour principle of the hydraulic moto at issue: Based on figure 1, suppose that the external grooves (10) of the rotor (2) are connected to the hydraulic pump of the system. Obviously, the internal grooves (11) of the rotor (2) will be in communication with the motor outlet. No matter the angular position of the rotor (2), the vanes (22) to (29) will be leaning on the sliding surface of the rotor (2). The communicant orifices (12) of the external grooves (10) are connected to the rotor (2) rabbets by means of internal passages (20). The oil coming from the pump passes through the external grooves (10), communicant orifices (12) and internal passages (20). In this way the flow is retained by the vanes (22) and (26) and the resultant pres sure acting on the faces of the rotor (2) will cause its clockwise revolving movement, until the vanes (23) and (27) lean on the internal circumferential trail of the rotor (2). At that moment these ones will prevent the oil flow, assuring the continuity of the rotor movement. Because of the movement of the rotor (2), the dammed up oil which is between the vanes (22) to (29) forces its way-out by the internal passages (19) through the internal grooves (11) communicant ori fices (13), towards the motor outlet. To achieve the gear reversion of the motor it is enough to invert the outlet and inlet by means of a directional valve inserted in the hydraulic circuit of the system. The contact between the vanes and the sliding trail of the rotor is provided by the vane operation oil circuit along the side grooves (15). This circuit is pressurized by the motor itself. The completely hydraulic circuit allows the vanes and rotor wastage without affecting the total capacity of the motor, thus increasing the endurance of the equipment. The fluid inj ection system through the side grooves of the rotor keeps the same diameter grooves under the same pressure on both sides of the rotor so that, no matter the load conditions, the rotor will be hydraulically balanced axlewise, reducing the wastage By mechanical friction and increasing the efficiency of the motor. We have thus, a hydraulic motor of extremely smooth operation, completely uniform speed and without any torque fluctuation whatsoever.

As in the present motor the areas under the same hydraulic pressure are always opposite as far as the longitudinal axle is concerned, there is no radial tension on the traction axle. d) BRIEF DESCRIPTION OF DRAWINGS

The descriptive figures below show constructive details of this invention and are component parts of this privilege ap plication.

Figure n. 1 shows the motor axlewise without the side lid and with the vanes and the rotor.

Figure n. 2 shows a longitudinal cut of the motor. e) BEST MODE OF CARRYING OUT THE INVENTION

The invention must be performed so that there be a minimum vane and rotor wastage without affecting the total efficiency of the motor. Therefore the contact surface of the rotor vanes must have the same radio so as to make the finishing easy by means of face grinding as well as its ulterior assembly. On the other hand, the geometric configuration of the rotor, the rabbets on its non-cylindrical surfaces, and the vane arrangement in the case must enable the alternation of the vanes in restraining the oil flow to be carried out in a uniform and smooth way. f) INDUSTRIAL APPLICABILITY

The present invention provides a new hydraulic vane motor, extremely simple and with exceptional operational characteristics in any duty conditions, especially adequate for equipment that demand wide speed range without the least torque oscilation.

It is advisable in equipment that needs smooth actioning at high speed and accuracy in reply, high degree of reliability and system denseness. Apart from that, it permits great plan flexibility, as for example in sugar cane grinding equipment cranes, etc.

Thus, this invention solves the problems for all the uses where high torque and low rotation are need which have up to the moment been solved through extremely sophisticated imported equipment as previously described or by complex mechanical systems which are far from being reliable and safe.

Claims

1 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, characterized by the fact of having an only symetrical lobular outline rotor (2), assembled in a circular case (1) with chambers for the vanes (22) to (29) and oil supply systems through the rotor (2) allowing the operating under a perfectly uniform speed regime without torque oscilation.

2 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, according to claim 1, characterized by the fact that the ro- tor (2) has oil side grooves (10) and (11) , on both sides to enable the hydrostatic suspension of the rotor (2) at the most different duty conditions, assuring correct self-location of the rotor (2) between the two covers (5) and (6) with the least mechanical wastage. 3 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, according to claims 1 and 2, characterized by having rabbets (18) on the non-cylindrical surfaces of the rotor, which enable the alternation of the vanes in retaining the oil flow without damaging the continuity of the traction torque. 4 - A HYDRAULIC MOTOR WITH VANES AND CONSTANT DISPLACEMENT, according to claims 1, 2 and 3, characterized by having a hydraulic circuit for vane operation (22) to (29) as the only operation means, pressurized by the very inlet line of the motor, constituted by two grooves (15), one on each side of the casing (1) imediately above the vanes (22) to (29) and linking all the vane chambers.