DE2226722A1 - SPEED CONTROLLER FOR A FLUID MOTOR - Google Patents

Description

Patent attorneys Dipl.-Ing. F. Weickmann, '

Dipl.-Ing. H.Weickmann, Dipl.-Phys.Dr.K.Fincke Dipl.-Ing. F. A. Weιckmann, Dipl.-Chem. B. Huber

, g MUNICH 86, DEN

PO Box 860 820

MÖHLSTRASSE 22, NUMBER 48 39 21/22 HOLLYMATIC CORPORATION <98 39 2l / 22>

bO North Street

Park Forest, Illinois, V.St, A.

Speed controller for a fluid motor

The invention relates to a speed controller for a fluid motor.

Such a speed controller has the task of controlling the speed of the fluid motor, which drives a tool, for example, to be kept roughly constant even with different loads.

According to the invention, this object is in the case of a hydraulic one Speed controller for a fluid motor solved by a fluid inlet with an inlet valve, consisting of a Valve seat, a valve that can be moved away from and towards the valve seat to regulate the flow rate of the fluid, a chamber formed on the side of the valve facing away from the valve seat and connecting paths for supply of pressurized fluid to this chamber, which exerts a pressure on the valve in the direction of the valve seat, a Outlet device for the controlled discharge of the pressure fluid

209886/073 / *

-Z-

out of the chamber, as well as through, one on centrifugal forces appealing device, which, with increasing speed, the outflow of the pressure fluid through the outlet device and thereby the control pressure in the chamber and thus at the same time on the valve as a puncture this speed increases.

The invention thus provides an improved fluid motor available in which the influx of the pressurized fluid to a rotor is controlled by a valve, which reacts to pressure changes in one of the valve seat surfaces of the Valve oppositely arranged chamber responds. For this purpose, devices are provided through which the fluid pressure in this chamber is increased with increasing speed, so that duroh the pressure build-up in this chamber shifted the valve in the direction of its closed position and thereby reducing the flow of pressurized fluid to the rotor so that its speed is controlled.

An embodiment of the invention is shown in the drawing and described in more detail below. Show it}

1 shows a partial longitudinal section through a fluid motor with a speed controller;

FIG. 2 shows, in an enlarged representation, a cross section in the area of the speed controller in a fully open view Position;

3 shows an illustration according to FIG. 2, in which the speed controller occupies an intermediate control position;

FIG. K shows, on an enlarged scale, details of the devices responding to the centrifugal forces; FIG.

209886/07 3 / *

£ 226722

- 3 - 5 shows a cross section along the line 5-5 in Figure 4;...

Fig. 6 is a cross-section along the line 6-6 in Fig. 2;

The pressurized fluid driven motor 10 shown in the drawings comprises a housing 11, in which a shaft 12 is rotatably mounted. In the illustrated embodiment, this shaft carries on her outer end a small grinding wheel 13.

At the rear end of the housing 11 an axial tube extension lh is formed, which is combined with a cover 15 to form an integral component and extends from this to the rear. The end 16 of a flexible compressed air hose is connected to this pipe extension 14. ,

The inner surface of the lid 15 is in the area which the inlet opening for the fluid or the passage 18 for the compressed air surrounds, formed flat, as shown at 17.

The rear end of the housing 11 is expanded and has a circular cross-section so that it forms a chamber 19. This chamber contains a rotor 20, which on the threaded rear end 21 of the shaft 12 is attached. The shaft 12 is within the Housing rotatably supported by two ball bearings 22, which are arranged at the two opposite ends of shaft 12 and only one of which is shown.

Compressed air or some other pressurized fluid flows through the passage 18 and a further passage 23, which in its central region is in communication with the interior 2k of the rotor 20, into the latter

V. 0 9 8 8 e / Ο 7 3 / <

Interior, the fluid flowing through the rotor transmits a torque to it. It is ejected from the rotor again through two outlet openings 25, which are arranged diametrically opposite on the rotor 20 having a circular cross-section, and of which in Pig. 1 only one is shown. From the outlet openings 25 from the air flowing through the chamber 19 in. The direction of the lid 15 to and from there through a plurality of openings 26 which are formed in the lid 15 _r outwardly "

The fluid passage 10, around which the rotor 20 rotates, surrounds a freely mounted sealing ring 27, which with a rear sealing surface 28 seals against the surface 17 of the lid 15 applies, and the front surface 29 of which is acted upon by the air pressure that is in the pressure chamber 30 prevails.

To control the rotational speed of the rotor 20 and thus the shaft 12 and the grinding wheel 13, a controller is provided. This regulator comprises a valve seat ring 31 made of metal, which is arranged with a press fit inside the cylindrical inner surface 32 which is concentric to the axis of rotation and also contains the free sealing ring 27 in its front region. This valve seat is essentially cylindrical like the sealing ring 27 and has a central passage opening 33 which is superimposed on the central passage opening Jk of the sealing ring 27. The valve seat ring 31 forms in this way the inside of the pressure chamber 30, diametrically through the valve seat ring runs ^v a metal pin 351 which is to prevent that small foreign bodies which are carried along by the fluid 37 'of the narrow bore 55 Controller penetrate. It also serves to hold the valve seat ring in place. The bore 55 is very narrow, in one embodiment, for. B. only 0.3 ^ mm in diameter.

209886/0734

With the surface 36 of the valve seat ring 31 'which forms the actual valve seat, an elongated, essentially cylindrically shaped valve 3 &' cooperates so that the flow rate of the pressurized fluid 37 through the passage 18 and the passage openings 3k and 33 which are concentric therewith can be controlled. The valve 38 is coaxial with the axis of rotation of the shaft 12. The essentially cylindrical valve Jü is movably mounted in an axial chamber 39 formed in the shaft 12. At its rear end it has a flat surface 40 which interacts with the valve seat surface 3 ° and completely shuts off the pressurized fluid when the valve is closed, as shown in FIG. The surface 4o has a circular shape and a diameter which is slightly larger than the diameter of the central passage opening 33 of the valve seat ring 31, with which it is concentric.

At the front end of the axial, cylindrical chamber 39, a circular step 4i is provided on which a circular flange 42 rests when da3 valve occupies its foremost position. This position corresponds to the maximum flow rate of the pressurized Fluid in the interior 24 of the rotor ,,

The valve 38 is in the cylindrical, axial chamber 39 movably supported by means of two ball bearings 43 arranged at a distance from one another. These ball bearings run during the movement of valve 3 & between its two End positions shown in Figures 1 and 2 on the inner surface of the chamber 39

By leakage of the fluid 37 ° ^v of the dos the interior rotor 24 through opening 23 leading n forward in the chamber ¹ 39 as well as to prevent from the chamber 53 to the rear, near the rear is Endos dos VEN

209006/07 3 4

BAD OFiIGJNAL

tiles 3Ö a ring seal is provided. In the illustrated Embodiment, this ring seal consists of two leather discs 44, which in an annular groove 45 of the valve attached and held by a fixed spacer washer 46 at a distance.

The structure of the valve 3 & consists essentially of a central, metal pestle 47 »the thickened one End carries the flange 42, and its forward adjoining area with a rigid plastic sleeve 48 is provided, in which two rings of radial openings 49 distributed on the circumference for receiving the ball bearings 43 are formed. In the front end of the Plunger 47 is a metal insert 50 with a circular splash 51, against which one side a pretensioned compression coil spring is provided. This coil spring is pretensioned so that it fixes the valve 3 & as shown in FIG presses against the ring 31 when the flow motor is not is under pressure.

The axial chamber 39t in which the valve 30 is arranged, forms at its front end a chamber 531 in which the preloaded coil spring 52 is located. To for that Both the plunger 47 and the insert 50 are used to ensure a flow of fluid to this chamber 53 each provided with longitudinally extending axial passage openings 54, which the narrowed, rear Inlet bore 55 in the area of the valve seat 36 with the insert piece 50 which forms the front end and which in turn is in communication with the chamber 53 associate. The passage bore 55 of the entire passage opening 54 is narrowed so far that it is from the Through opening 23 in the chamber 53 branched off fluid quantity certainly.

BATH ORIGINAL

Ί 0 9 8 8 6/0 7 :) A

The chamber 53 serving as a valve control chamber is located on the side or at the end of the valve 3O ₁ which is opposite the valve seat 36. The pressurized fluid in the chamber 53 acts in conjunction with the helical spring 52 in the sense that the valve 3 & is displaced into its closed position shown in FIG. 1 or to the right, as FIGS. 2 and 3 show on an enlarged scale .

In order to control the pressure acting in the closing direction on the valve fluid pressure in the chamber 53, an outlet means is provided through which this chamber is relieved in response to a centrifugal force * These outlet means comprises a closure member 561 which is pressed into the front end of the axial chamber. 39 This metal closure piece 5 ° is provided with an outlet path. This outlet path comprises a side passage 57 on the underside of the closure piece, a passage 5 &quot; leading radially inward into an inner chamber 59 and a forward passage 60 "which opens into an anterior chamber 61. The anterior chamber is circular through a radial passage 62 Fluid passage 63 connected, which is located between the shaft 12 and the housing 11.

The front end of the closure piece 56 carries a seal 64 in an annular groove 65, which seals against the inner surface of the chamber 39 ^a n its front end.

In the inner chamber 59 of the closure piece 56 there is a stopper 66 which is not guided all the way to the end of the inner chamber in the area of the radial passage 5 and so that a connection between the passages 5 and 60 remains. This end of the plug 66 facing the passage 5 ^ has an incorporated chamber 6? which extends substantially radially and is connected to a PaHKHfJO 'jri, which is substantially

>'Γ) B -fl 8 6 AO 7 3 U

BAD OftlßiNAL

runs parallel to passage 60 and also opens into chamber 61. In the chamber 67 there is a metal ball 69 which can rest against the inner edge 70 of the radial passage 58 when it is pressed outward by the centrifugal force of the rotating shaft 12. In this way, the ball 69 controls the pressure relief of the chamber 531 by opening a path for the fluid from the chamber 53 via the passages 57, 58, 60 and 62 to an area under normal atmospheric pressure. To ensure that behind the ball 69 there is no pressure even at the changing speeds of the motor, the area behind the ball or - as shown in the drawing - above the ball via the passage 68 is also connected to the chamber 6t. In this way, the ball 69, together with the arrangement described, is a device responsive to the centrifugal force, with which the outflow of the fluid controlling the valve through the passages 58 to 62 is reduced with increasing speed, so that at the same time the pressure of the control fluid in the Chamber 53 rises. Any increase in the control pressure in this chamber naturally causes, in conjunction with the force of the spring 52, a displacement of the valve to the rear or - in the illustrated embodiment - to the right. The inlet of the fluid 37 into the interior Zk of the rotor 20 is controlled by the valve together with the valve seat 36. In those cases in which the fluid pressure in the interior space 2k of the rotor is relatively low compared to the fluid pressure in the inlet 71, the helical spring 52 is not required per se.

The axial chamber 39 in the shaft 12, in which the axially movable valve 38 and the associated components is concentric with the axis of rotation of the rotor, with the valve, the valve seat 311, the diaphragm ring 27

209886/0734

- 9 -.
and the passage 18 for the pressurized PIuId ₀

The operation of the regulator is as follows: When the fluid motor is at rest and there is no fluid pressure in the inlet 10, the valve 33 assumes its closed position under the action of the helical spring 52, as FIG. 1 shows. In this position, the sealing surface kO of the valve lies on the valve seat ^{surface 36 a} n »As soon as a pressurized fluid 371, for example compressed air, is supplied through the passage 18, the valve 30 moves completely to the left under the effect of this pressure, as shown in FIG 2 shows so that the annular flange k2 rests against the annular step 41, which serves as a stop for the movement of the valve. During this short time, fluid already flows from the inlet 71 through the passage 5k of the valve 38 into the chamber 53 and through the passages 57 to 62. At the same time, the fluid pressure in the interior 2k of the rotor causes the rotor, and thus the shaft 12, to rotate begins, which is connected to the rotor. The resulting centrifugal force presses the ball 69, which is thereby loaded, outwards against the seat 70. The closing of the outlet path from the chamber 43 in conjunction with the force of the spring 52 results in a movement of the valve 38 from the position shown in FIG. 2 to the right , since a certain dynamic pressure builds up in the chamber 53. The speed of the rotating rotor and the shaft connected to it are set to a controlled value. The valve 38 and the associated ones are at this speed. Parts in the middle position shown in Fig. 3,

If there is a tendency for the speed to increase, the ball 69 rests closer to its seat 70, so that a higher back pressure builds up in chamber 53 and the valve is moved further to the right, so that the inflow to the rotor is more restricted and on

2 098 86/0734

in this way its speed is reduced. If, on the other hand, the speed threatens to drop, for example because the grinding wheel 13 is more heavily loaded, the centrifugal force acting on the ball 6 ° is also reduced. The ball is lifted from its seat 70 under the influence of the fluid so that more air can flow out of the pressure chamber 53, the valve 38 shifts to the left again, and the influx of the pressurized fluid 37 to the interior Zh of the rotor again increases.

In a typical embodiment, the ball 69 has a diameter of about 1.6 mm and weighs about 0.016 g, At 80,000 rpm, the center of the sphere is approximately 0.71 mm from the axis of rotation. At this speed of rotation the distance of the ball from its seat 70 is about 0.025 mm.

When the valve 3 # assumes its closed position - FIG. 1 shows this position in which the valve is not acted upon by any pressure fluid - the surface 40 completely covers the passage opening 33, which is determined by the inner surface of the valve seat ring 31. When pressurized fluid 37 flows in through inlet 10, it exerts a pressure on the surface 40 of the valve and lifts it off the valve seat 6. This immediately results in the pressure of the fluid on a larger area of the valve becomes effective when it represents the sealing surface kO alone, because now the fluid 37 can ^{flow around} the circular flange h2 and press on the seal kk , which protrudes circularly downstream of the sealing surface kO, as best shown in FIGS. 2 and 3 This means that the total force which acts on the valve and this from its position shown in FIG

209886/07

into the completely shifted position according to FIG. 2 shifts is larger because the surface area under pressure is larger.

The incoming pressure fluid 37 first moves the valve 38 over its entire free path to the left, as shown in FIG. 2, until the flange kZ rests against the shoulder 41. As a result, most of the fluid is directed radially outward into the interior Zk of the rotor 20, so that it begins to rotate. At the same time, however, a small part of flows of the fluid through the passages 55 and 5k in the chamber 53 1 in which a traffic jam or Scjiließdruck builds up, which on the front or, left-hand end of the valve kö acts and the fluid pressure on the rear end or the surface kO of the valve is opposite. This dynamic pressure in the chamber 53 in conjunction with the action of the spring 52 tries to move the valve 38 back or in the closing direction. In a specific position, which depends on the speed of the rotor 20 and the associated shaft 12 to the ¹ arranged thereon components, taking the valve kö a mean regulating position between the fully open and the fully closed position a, such as in Fig. 3 is shown.

In the speed controller shown, the forces acting on the valve are balanced, so that the operation of the valve is very gentle and it reacts immediately to changes in the load or the speed. Accordingly, when the valve 38 moves to the right in the closing direction, the fluid pressure acting on the surface kO increases, since less fluid can flow into the interior 2k between the surface kO of the valve and the ring 31 due to the reduced distance. This reduced fluid flow into the interior Zk of the rotor

209886/07.? / <

extends the pressure in this interior space and at the same time also the fluid pressure acting on the annular surface of the seal kh. At the same time, the force of the pretensioned spring 62 acting in the closing direction is also smaller, since the spring relaxes when the valve is moved in the closing direction. The result of all these forces is deiaxb that the decreasing forces do not completely outweigh the above-described force on the surface 40, which increases with a closing movement of the valve, so that with a closing movement of the valve the overall forces acting on the valve increase slightly that the operation of the valve is very gentle during a closing movement and that an equilibrium position is established, as shown in FIG. The speed difference of the rotor and thus of the shaft 12 under different loads is very small. For example, at an operating speed of 50,000 rpm, the speed difference between low and heavy load was only about 50 rpm.

From the above you can see that the regulator by regulating the fluid supply from the passage opening 18 to the rotor 20 becomes effective. The regulator is therefore applicable to any device operated by a pressurized fluid, in which a gaseous or liquid Fluid is used to drive an engine.

The valve 3 ^ works as a throttle valve, which the Fluid flow throttles if necessary. Part of the pressurized fluid flowing into the machine is branched off and serves to in cooperation with a pretensioned spring a Exert closing force on the valve. This branched off fluid is either drained into the open as required, thereby reducing its effect, or preventing this outflow, whereby the outflow is controlled takes place via the centrifugal forces, which on a by the centrifugal loaded ball 69 act.

20988fi / G7 _3/4

Claims (1)

PATENT CLAIMS 1, j speed controller for a fluid motor, characterized by a fluid inlet (18) with an inlet valve, consisting of a valve seat (36), a valve (3 * 0 which can be moved away from the valve seat and towards it) for regulating the flow rate of the fluid (37 ) »A chamber (53) formed on the side of the valve facing away from the valve seat, as well as connecting _{paths (55 f} 5 * 0 for supplying pressurized fluid to this chamber, which exerts pressure on the valve in the direction of the valve seat, an outlet device for controlled Discharge of the pressurized fluid from the chamber, as well as a centrifugal-responsive device (69 »70), which with increasing speed reduces the outflow of the pressure fluid through the outlet device and thereby increases the control pressure in the chamber and thus simultaneously on the valve as a function of this speed . 2. Speed controller according to claim 1, characterized in that the connection paths for. the pressurized fluid to the chamber (53) comprises a passage leading through the valve and facing from the one facing the valve seat (36) End to the chamber (53) facing end of the valve (30). 3. Speed controller according to one of claims 1 and 2, characterized marked j that before the leading through the valve (3 * 0 Passage (55 | 5 ^) © is provided in the obstacle, keeps soft foreign bodies away from this passage, k. Speed regulator according to one of Claims 1 to 3 »characterized in that the fluid motor is essentially formed by a rotor (20) which is fastened on a shaft (12) rotatable about its axis, that the solid has a central longitudinal bore (39) , in which 209886/0734 the valve (3 &), the chamber (53) and the device (69, 70) responding to centrifugal forces are arranged, the valve being movable in the bore and being sealed against the inner walls of the bore by a seal (kk). 5. Speed controller according to one of claims 1 to 4, characterized in that the valve (3 ^) within the bore (39) can be moved towards and away from the valve seat in the longitudinal direction, and that the shaft (12), the valve, the valve seat (36), the bore (39), the connecting paths (55,54) and the axis of rotation of the rotor (20) and the shaft (12) are coaxial with one another. 6. Speed controller according to one of claims 1 to 5 »thereby characterized in that the fluid inlet (iö) is concentric is arranged to the axis of rotation of the rotor (20) and the shaft (12). 7. Speed controller according to one of claims 1 to 6, characterized in that the connecting paths (55 _t 5h) to the chamber (53) arranged in the shaft (12) have an inlet (55) in the region of the fluid inlet (iü) as well as having an outlet opening into the chamber, ti. Speed controller according to one of Claims 1 to 7 »characterized characterized in that the outlet means for the chamber (53) has a substantially radially extending passage (5ü), which is provided with a valve seat (70) is, and that the responsive to the centrifugal forces Device has a thereby loaded valve part, which upon rotation of the rotor (20) or the shaft (24) is pressed against the valve seat. 209886 / 07Ή Speed controller according to one of Claims 1 to 8, characterized
characterized in that the valve part is represented by a ball {69) movable in the radial direction, which
by their movement towards the valve seat (70)
limited to the flow rate through the outlet device. 10 «speed controller according to one of claims 1 to 9, characterized in that the valve part is in a chamber (67)
is arranged movably under the action of centrifugal force, and that the end of the chamber opposite the valve seat (? 0) has a relief line (68) connected to the outlet device. 11. Speed controller according to one of claims 1 to TO, characterized in that the valve (38) by spring means in
Direction on the valve seat surface (36) is to be loaded
and thereby, in addition to the action of the pressure fluid located in the chamber (53), a valve that closes the valve
Exerts force. 12. Speed controller according to one of claims 1 to 11, characterized in that the spring means by one in the
Chamber (53) arranged spring (52) are formed, which
presses on the side of the valve (38) which is opposite to the valve seat surface (36). _: 13 · Speed regulator according to one of Claims T to 12, characterized in that the spring (52) acts as the axis of rotation
the rotor (20), the shaft (24) and to the valve (38)
is formed coaxially arranged coil spring. 20 9 a8-.fi-Aft-T