IL36171A - Vibrator driven by compressed air - Google Patents

Description

Vibrator driven by compressed air 98 The present invention concerns a vibrator of the type comprising an eccentric body enclosed in a the eccentric body being arranged to be set in motion in an eccentric and rolling movement inside the under the influence of the static pressure of the medium passing through the The pressurized medium in hitherto know vibrators of thi type is usually The static pressure is obtained by means of a valve device located in the air flow path and the valve device is affected by the eccentric body its rolling motion in such a manner that the valve device is alternately causea to ana close the inlet passage for the air flowing through the vibrator and by this mean eccentric body is affected by the pulsating air The aisadvantage of this design is primarily the wear to which the valve device is exposed and the risk that dust and impurities will enter sliding or bearing surfaces of the thus causing maloperatio In valve device represents a part which introduces a complication from manufacturing as well as operating Compressea air vibrators in the dynamic energy of the air is without the above mentioned device have also been such vibrators require higher flow and a higher air flow velocity through the viorator order to attain a performance comparable with that valve The purpose of the present invention is to eliminate these disadvantages and for this comprises a hollow cylinder within which a cylinuer of a smaller diameter is one of the cylinders being rotatable in to the other The characteristic feature of the invention is that the cylinder with the smaller meter is provided with screw threads on its periphery which engage with screw threads provided on the inside of the enveloping the number of starts of the thread in the enveloping cylinder being one more than the number of starts of the thread in the internal The threads in the bore of the larger cylinder may present some manufacturing especially on small long A further aim of the invention is fore to these internal threads in separate rical bushes in axial are equal to or shorter than the threaded portion on the cylinder inside the The minimum total length of these bushes should be equal to one pitch of order to prevent the pressurized medium from flowing directly through the without the static pressure of the medium being the bushes are of size that their largest bore is one height of thread greater than the outside diameter of the smaller The number of starts of the screw thread the bushes is one more than the number of starts of the thread on the The bushes are designed to be entered into the vibrator casing and to be placed axially in relation to each thus enclosing the threaded section of the smaller simplification can be carried a stage further by making the bushes from a simpler and more easily machined material than that of the remainder of the which is normally made of The aim of the invention is to make this possible b providing the rotating cylinder or rotor with special tracks which will operate in conjunction with tracks provided on the of the These tracks are designed to carry all the centrifugal force generated by the rotor during its eccentric rolling thus taking up all the load which would otherwise be carried by the threaded sections of the rotor and making the bushes in relatively small lengths in accordance with the the execution of the internal threads is simplified As mentioned the material of the bushes can be the same as that of the remainder of the casing since the centrifugal force generated by the rotor is absorbed entirely by the tracks of the rotor it is also possible to make the sleeve of plastic or similar easily machinable The invention will be described in more detail in the with reference the drawings where shows a longitudinal section through variant of the invention designed for being driven by means of compressed air and intended for the compaction of concrete and 2 shows a transverse section of the vibrator across line in 1 and to a somewhat larger Item 1 designates the casing of the in which rotor 2 is Threads 3 are formed in the internal surface of the casing and in the example these threads are formed in three separate bushes located inside the and arranged axiallv in relation to each These threads with threads on the periphery of the rotor and each end of rotor 2 side the threads is provided with a plain section these sections being in contact with tracks 7 arranged on the of the A channel is provided centrally inside the rotor 2 arid this with the air inlet 9 which is in the form of a hose A compressed air hose 10 is threaded onto the hose coupling and in the variant the hose is enclosed in a tubular case At the opposite the casing is closed by means of an end piece 12 to the casing and formed in such a manner that air can flow from channel into the space between the portions of the rotor and As shown in threaded portion of the rotor is designed in such a manner that when the crest of a thread on the rotor is against the root of the thread in the the diametrally opposed of the rotor thread is against the crest of thread in The relationship between the of the rotor and casing tracks is such that the radial centrifugal force generated during tne eccentric rolling motion the rotor absorbed entirely by the In tne example the vibrator operates in the following Compressed air is supplied through hose through the air inlet 9 on the vibrator and channel 8 in rotor 2 up to the sections of the rotor and A torque is thus applied to the rotor and the rolling motion of the rotor along the tracks 7 of the casing is thus Each thread on the rotor forms a space in conjunction with corresponding thread in the casing and this space is Owing to tne different number of starts of the threads the rotor and the this space will move along the wnole of the threaded section as a result of the rolling movement of the The space thus has the shape of a spiral loop around the tne length of the loop corresponding to the pitch of the After the air has been back and thus carried out its driving is directed to the exhaust opening 13 of the 6 insufficientOCRQuality

Claims (1)

1. CLAIMS le Vibrator driven by pressurized medium and consisting of a hollow cylinder and a cylinder of smaller diameter eccentric-alfcrarrattged inside the hollow cylinder as well as inlet and outlet openings for the pressurised medium, one of the cylinders being rotatable and adapted to be brought into a vibration-generating rolling movement in relation to the other cylinder by the aid of a flow of pressurized medium passing through the vibrator, wherein the cylinder of smaller diameter is provided with screw threads on at least the most part of the axial length of its envelope surface, these threads engaging with threads being provided on the inside of the surrounding cylinder the number of starts in the thread of the surrounding cylinder being one more than the number of starts of the threads of the smaller cylinder, each thread on the smaller cylinder forming a space in conjunction with corresponding thread of the surrounding cylinder, said space thus enclosed having the shape of a spiral loop the length of which corresponding to the pitch of the thread, 2» Vibrator according to Claim 1 wherein the threads of the surrounding cylinder are formed in separate cylindrical bushes which are arranged axially in relation to each other inside the surrounding cylinder. 3· Vibrator according to Claim 1, wherein the threads of the surrounding cylinder are formed in separate cylindrical bushes, which are arranged axially in relation to each other inside the larger cylinder and which are axially equal to or shorter than the threaded section of the smaller cylinder, the total minimum length of the bushes being equal to one pitch of thread* 36171/2 - - 7 - cylinder is provided with a plain cylindrical section at each end, these sections being in contact with tracks arranged on the inside of the enveloping cylinder and the diameter relationship between the plain sections and the corresponding tracks being selected in such a manner that the centrifugal force generated by the eccentric rolling movement of the smaller cylinder is taken up entirely by the tracks* 5« Vibrator according to Claim 4 wherein the bushes are desig ed so that their outside diameters are equal to the inside diameter of the surrounding cylinder and that their largest inside diameter is one height of thread larger than the outside diameter of the smaller cylinder* 6· A vibrator substantially as hereinbefore described by way of example and with reference to the accompanying draw** lngs# for the Applicants DR. REINHQLD COM AND PARTNERS By*