GB2066901A

GB2066901A - Rotary positive-displacement fluid-machines

Info

Publication number: GB2066901A
Application number: GB8040593A
Authority: GB
Original assignee: Tovarny Strojirenske Techniky
Current assignee: Tovarny Strojirenske Techniky
Priority date: 1979-12-21
Filing date: 1980-12-18
Publication date: 1981-07-15
Also published as: FR2472076A1; FR2472076B3; IT8026835A0; NL8006923A; DE3047422A1; JPS56129702A; CS215959B1; PL228602A2; SE8009022L; DD160839A3; GB2066901B; IT1134832B; BG41251A1

Abstract

In a motor unit of the oscillating- vane type a vane 5 oscillates between stops 7, 8 in an annular chamber containing a fixed partition 9, which is associated with working-fluid inlet and outlet openings 10, the upper stop 7 being movable along said chamber so as to vary the stroke length. Protuberances, or "roots", 6 co-operate with throttling grooves in the stops so as to cushion the vane at the end of each stroke. A plurality of such units may be disposed co-axially and the shafts thereof connected to one another end- to-end, Figures 4-6 (not shown). <IMAGE>

Description

SPECIFICATION Adjustable rotary vane drive controlled by a pressure medium The invention relates to an adjustable vane type rotary drive controlled by a pressure medium with an adjustable stroke and progressive damping of the approach to extreme positions.

Actually known rotary adjustable drives controlled by a pressure medium can be divided to three groups. The first group of drives includes the most extensively used designs. They have substantially a cylindrical body of the drive with a flange or supporting shoesforfixing, housing a rotorwith one, two or three vanes rotatably supported, where the working space is divided by the same number of partition walls, which act simultaneously as stops.

The operating angle of the rotor is here limited by the number of partition walls. These drives have no proper damping means and the working spaces, the rotor and the vanes are packed by inserts which reduce by their friction the resulting working torque.

A second group is represented by a rotary piston cylinderfora hydraulic and pneumatic drive. It consists of a cylinder which forms the body of the drive, with an inlet on each end, of a disc provided with lateral bolts and multi-threaded external threads with about 45" pitch angle, which are of opposite directions and which are supported by nuts. One nut is anchored not rotatably in the cover of the drive. The second nut forms one end of the rotor. The other end of the rotor is a bolt for transmission of the torque. By supply of pressure medium to one or the other inlet, the disc is by a helical motion shifted from one end of the cylinder to the other one.The rotary motion of the drive is thus derived from a helical motion of a disc by cooperation of a fixed nut in the cover firmly connected with the body of the drive, of the bolts of the disc and of the nut of the rotor. The rotor is radially and axially supported rollingly by the second cover of the drive so that it is able to perform a rotary motion only. The drive is supplied in addition to standard embodiments in different modifications. One of them comprises an adjustably arranged turning angle of the rotor - what is accomplished by axial shifting, by non-rotatable supporting of the nut in the drive cover, furthermore there is a selectable damping in extreme positions. The drive is of high technical level, but it requires by its design and solution a demanding technology and accuracy of manufacture.The threaded part of the drive is the most vulnerable part of the drive, where at a slightest lack of maintenance of accuracy or due to wear a resulting clearance shows unfavourably at an inertial load on a smooth and continuous operation.

The third group, which by its original solution belongs rather to the first group has an innovation regarding the selectability of the angle of turning of the rotor and by a final damping in the given range of turning. The given parameters are of high level.

However the range of adjustability of the angle of turning of the drive for sizes up to 750 Nm is only 1800 and is not extended by the innovation.

It is an object of this invention to provide a rotary vane type drive enabling by progressive damping a smooth starting and stopping without shock and with reasonable dimensions of the drive.

The rotary vane drive device controlled by a pressure medium with adjustable angular stroke and progressive damping of approach to extreme positions according to the present invention comprises at least one working section, said working section consisting of an annular body with side walls and a partition wall, determining a working space, a rotor provided with a vane rotatably supported within said side walls, inlet openings into the working space at both sides of said partition wall, one of said side walls being fixed relative the body, a stop fixed to the fixed side wall, limiting the angular stroke of the rotor, the other side wall being angularly adjustably connected to the body, a limiting stop fixed to the adjustable side wall, at least one throttling groove provided both in the stop connected to the fixed side wall and in the limiting stop connected to the adjustable side wall, and damping roots provided on the rotor of the working section provided with a vane.

The rotary vane drive according to this invention enables by its progressive damping, the stoppage and starting of the rotor to proceed smoothly without shock. It is of small dimensions and of compact shape, an efficient drive for a required angular working stroke with a small number of parts reducing or eliminating maintenance. The progressive damping and a return valve with a groove for starting are advantageously utilizing the internal spaces of the drive. The damping is effective for the given range of load torques, speed and unbalanced loading. The angular stroke of each working section is coarsely adjustable within distances of screws, continuously within the range of arcuate openings of the adjustable second side wall so that practically any angular stroke up to 270 is enabled.It enables arrangement to be formed with standard components consisting of two or more sections connected on one axis so that the angular stroke and angular speeds of turning of individual sections can be added or subtracted in selected cycles. The rotor formed with a vane and with damping roots enables to achieve higher dynamics and torques of the drive at small dimensions, utilizing higher pressures of the working medium. The inlet openings of each working section are front or radial, some of them can be blind, so that the remaining openings remain in operation according to the required assembly of the drive. When a maximum angular stroke of a working section is adjusted, its operation can be controlled by a servo slide valve for adjustment of further intermediate positions of the angular working stroke.The design of each working section is solved so that it contains a minimum of friction surfaces, which are two only, namely packings on the outlet bolts of the rotor. Due to this design a maximum sensitivity is achieved and mechanical losses of the drive are reduced to a minimum. By interconnection of both front packing surfaces of the drive by interconnection openings a hydraulic equilibrium is achieved. If the drive consists of two or more working stations a solution is proposed for supply of pressure medium supplying the taken along section either by a fixed supply by means of rotary distributors or supply bores in the rotor of the supporting working section or by way of mobile hoses. At thus designed drives the overall angular working stroke can be a multiple of the angle 270".

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a working section of a rotary vane drive device in a sectional view along a plane A - A indicated in Figure 2 according to one embodiment of the invention, Figure2 is a working section in a partly sectional elevation, the section taken along a plane B - B indicated in Figure 1 and partly in a view on the adjustable side wall in direction of the axis of the drive, Figure 3 is a detail of a section along a plane C - C indicated in Figure 1, the staggered section passing in the plane of the throttling groove and further in the plane of the return valve and supply of the pressure medium, Figure 4 shows in a second embodiment of the invention the connection of the working section when a taken along section is supplied by not shown mobile hoses, Figure 5 shows in a third embodiment of the invention the interconnection of two working sections whereby the feeding of the taken along section by a rotary distribution is indicated in partly section, Figure 6 shows in a fourth embodiment of the invention the interconnection of two working sections, whereby the feeding of the taken along section over bores in the bore rotor of the supporting working section is indicated in partly section.

Each working section 100 and supporting working section 101 consists of a body 1 provided with a fixed side wall 3 with a fixed stop 8 and a partition wall 9, to which body 1 an adjustable side wall 2 with a fixed limiting stop 7 for limiting adjustable extreme positions of the angular working stroke are angularly continually adjustably fixed. A rotor 4 of a working section 100 or a bored rotor 26 of a supporting working section 101 is rotatably supported in the side walls 2, 3. Each working section 100 and supporting working section 101 is provided with front inlet openings 11 and radial inlet openings 10 terminating at both sides of the partition wall 9 into the internal space of the drive.The rotor 4 of the working section 100 and the bored rotor 26 of the supporting working section 101 is designed as a unit with a vane 5 and with damping roots 6 so that the chamfered entering edges 14 of damping roots 6 together with throttling grooves 12 formed in the stops 7,8 together with the throttling grooves 12 determine a space narrowing in wedge fashion for progressive damping of the approach of the vane 5 towards the stops 7, 8.The stops 7,8 are provided with return valves 13 terminating in a gap 16 for enabling a continuous start of the vane 5 from stops 7 or 8, achieved in that pressure medium enters in the course of starting the vane 5 in the permeable direction over the return valve 13 into the gap 16 between stop 7 or 8 and the vane 5 and acts solely on a part of its radial surface so that the starting torque is determined by the ratio of the radial surface of the gap 16 to the radial surface of the vane 5 including the damping root 6. The gap can be made either by a planar recess of either the vane 5 or of the stops 7, 8.

The adjustable side wall 2 is fixed to the body 1 by screws 20 passing through arcuate grooves 19 arranged so as to secure a continuous angular adjustment of the working stroke of each section 100 and of the supporting working section 101. Each working section 100 and the supporting working section 101 enable a continuous adjustable angular stroke of the rotor up to about 270". The adjustment of the required angular stroke is accomplished so that the adjustable side wall 2 is approximately adjustable for a multiple of distances apart of screws 20, further within the angular distance of arcuate grooves 19 there is a possibility of continuous adjustment of the required angular stroke.

Each working section 100 and the supporting working section 101 have the front packing surfaces 21 of the rotor 4 or of the bored rotor 26 provided with at least one interconnecting opening 15 for hydraulic balancing.

If a drive device is to be assembled with two equal working sections 100 as shown in Figure 4, a taking along hub 22 is fixed on the rotor 4 of the taking along working section 100, by means of which the taken along working section 100 is fixed. It is thereby possible to provide the stable taking along working section 100 fixed on the frame 25 with not shown stable supply means of pressure medium terminating according to need to front inlet openings 11 orto radial inlet openings 10, whereas the mobile taken along working section 100 has to be provided with not shown mobile supply means of pressure medium, for instance with pressure hoses terminating in radial inlet openings 10 or front inlet openings 11.

In another alternative arrangement as shown in Figure 5 with two equal working sections 100, a distributing hub 23 is fixed on the rotor4 of the taking along working section 100, on which hub 23 a body 24 for a rotary distributor is rotatably supported and to which the taken along working section 100 is fixed, in which hub 23 a distributing channel system 30 is formed connected to distributing recesses 29, to which inlet openings 28 of the body 24 for rotary distribution are terminating. This channel system 30 terminates on the other side to front inlet openings 11 of the taken along working section 100. The distributing recesses 29 can be thereby made either in the internal cylindrical surface of the body 24 for a rotary distribution between the packings 31 or in the external cylindrical surface of the distributing hub 23. This alternative enables a maximum number of assembled working sections 100 as the bodies 24 for rotary distribution can be always fixed to the frame 25 so that all supplies of pressure medium can be stable.

In a further alternative one individual working section 100 and one supporting working section 101 are assembled as shown in Figure 6. The fixed supporting working section 101 is provided with a bored rotor 26, on which a supply hub 27 is fixed, to which the working section 100 is fixed and in which hub 27 a supply channel system 34 is formed, connected to inlet bores 33 of the bored rotor 26 of the supporting working section 101 and terminating to front inlet openings 11 of the working section 100.

The supply of pressure medium to the supporting working section 101 can be fixed, whereas for the working section 100 it has to be made by not shown mobile hoses terminating to a supply block 32 connected to inlet bores 33 of the bored rotor 26. An advantage of this arrangement is that no friction losses and no losses of pressure medium are experienced in comparison with the application of a rotary distribution 23, 24. This arrangement enables furthermore equally an assembling of the drive from several working sections 100 taken along by a supporting working section 101, of course with the application of a rotary distributor 23, 24 for each further working section 100.

In the course of operation of the drive the rotor 4 or the bored rotor 26 performs a reciprocal motion within the working space determined by stops 7,8 with an automatic progressive damping prior to reaching both extreme positions. The partition wall 9 separates in co-operation with the rotor 4 or with the bored rotor 26 and the vane 5 and damping roots 6 the working space to two chambers namely a pressure part and a part connected with the waste and vice versa (alternately according to the direction of motion of the drive). The working stroke of the drive is damped prior to reaching the extreme position by stop 7 or 8 which are arranged so that the approach (start) of the rotor is smooth and without shocks.The damping is achieved in that the volume of pressure medium enclosed between the vane 5, root 6, adjustable side wall 2 and stable side wall 3 and the body 1 is throttled over the throttling grooves 12 and the stop 7 or 8 which is at this moment operating. A possible axial unbalance due to hydraulic action is prevented by hydraulic interconnecting openings 15 of both front packing surfaces 21 of the rotor 4 or of the bored rotor 26. The maximum sensitivity and minimum mechanical losses of the drive are obtained by reduction of friction surfaces to a minimum namely by packing rings 17 situated in the cover 18. The feeding of the drive composed of several working sections 100 and possibly also one supporting working section 101 can be achieved either by means of not shown mobile hoses or by means of bodies 24 for rotary distribution and possibly by means of a bored rotor 26.The coaxial connection of these sections can be in that case achieved either by taken along hubs 22 or by distribution hubs 23, possibly by a supply hub 27. Each taken along working section 100 mobile with respect to the frame 25 can be supplied over radial inlet openings 10 orfront inlet openings 11 by means of mobile hoses or by fixed supplies of pressure medium by way of inlet openings 28 of the body 24 for rotary distribution, each of which terminates into one of distributions recesses 29, furthermore to the distributing channel system 30 in the distributing hub 23 terminating in front inlet openings 11. The body 24 for rotary distribution can be secured against turning for instance by not shown means for fixing to the frame 25. The body 24 for rotary distribution is secured against leakage of pressure medium by a packing 31.If the drive is assembled from one supporting working section 101 and at least one working section 100, the bored rotor 26 of the supporting working section 101 fixed on the frame 25 serves for supply of pressure medium without losses to the first taken along working section 100. The pressure medium is in that case supplied from not shown mobile hoses through a supply block 32, inlet bores 33 in the bored rotor 26 of the supporting working section 101 to the supply channel system 34 in the supply hub 27 and thus to the front inlet openings 11 of the taken along working section 100. Possible further taken along working sections can be fed by above mentioned means.

The rotary vane drive according to this invention has as a driving unit a rather wide application. It can be used for manipulators and feeding means of different types, for different applications for manipulation with material, tools or workpieces for machine tools and other related branches. A drive composed of two or more working sections enables furthermore an increase of the overall stroke according to the number of used sections in multiples of the angular stroke of one section of 270 .

Claims

1. Rotary vane drive device controlled by a pressure medium with adjustable angular stroke and progressive damping of approach to extreme positions comprising at least one working section, said working section consisting of an annular body with side walls and a partition wall, determining a working space, a rotor provided with a vane rotatably supported within said side walls, inlet openings into the working space at both sides of said partition wall, one of said side walls being fixed relative the body, a stop fixed to the fixed side wall, limiting the angular stroke of the rotor, the other side wall being angularly adjustably connected to the body, a limiting stop fixed to the adjustable side wall, at least one throttling groove provided both in the stop connected to the fixed side wall and in the limiting stop connected to the adjustable side wall, and damping roots provided on the rotor of the working section provided with a vane.

2. A device according to Claim 1 wherein a plurality of working sections are provided and which are mutually connected coaxially.

3. A device as claimed in Claim 1 or 2 wherein the damping roots of the rotor are provided with chamfered entering edges forming together with throttling grooves of side walls of the drive a narrowing space for progressive damping of the approach of the vane to the stop.

4. A device as claimed in any one of Claims 1 to 3 wherein a gap is provided between a part of the surface of the vane of the rotor and the co-operating stop on one of the side walls, return valves terminating into this gap, enabling a smooth removal of the vane from the stop.

5. A device as claimed in any one of Claims 1 to 4 wherein at least two arcuate grooves are provided in the angularly adjustable side wall for adjustable fixing of the adjustable side wall to the body of the drive.

6. A device as claimed in any one of Claims 1 to 5, comprising at least two similar working sections, one of which being a taking along section, the other a taken along section, a take along hub fixed to the rotor of the taking along section, the other section fixed to said take along hub.

7. A device as claimed in any one of Claims 1 to 5 comprising at least two similar working sections, one of which being a taking along section, the other a taken along section, a distributing hub fixed to the rotor of the taking along section, a body for rotary distribution of pressure medium rotatably supported on this hub, the taken along section fixed to said hub, a distributing channel system provided in this hub, distributing recesses provided between the hub and the body for rotary distribution, these recesses connected to the distributing channel system, inlet openings of the body for rotary distribution terminating into these recesses, front inlet openings provided in the taken along section, the distributing channel system terminating into these front inlet openings.

8. A device as claimed in any one of Claims 1 to 5, comprising at least one working section and one supporting working mutually coaxially connected, the supporting working section provided with a bored rotor, a supply hub connected to said bored rotor, the working section fixed to said supply hub, a supply channel system formed in the supply hub, supply bores provided in the rotor of the supporting working section and connected with said supply channel system, front inlet openings provided in the working section, the supply channel system terminating into these front inlet openings.

9. A device as claimed in any one of Claims 1 to 8, the front packing surfaces between the body of the drive and both side walls provided with at least one interconnecting opening for hydraulic balancing.

10. Rotary vane drive device controlled by a pressure medium with adjustable angular stroke and progressive damping of approach to extreme positions substantially as described, with reference to any one or more of the attached drawings.