DE1453446A1 - Device for controlling the displacement of a liquid pump or a liquid motor - Google Patents

Description

Ρβ '<it

• vW> »,. Many a rter l / fe-20095 Münohen-lPullach, September 20, 1963

SRAKESHOB INTERJSATIOHAI SA, 21 Ohemin Terroux, Grand-Sacconex, Geneva, Soheia

Device for controlling the displacement of a liquid pump or a liquid motor

Dit invention "refers SiOH on Druckflüssigkeitsübertragungsvorriohtungen variable displacement! As Z ₀ as pumps and motors, which are equipped with devices which the liquid sverdrängung per stroke or per revolution of the device may change · You machine formed as a piston engine, having wings or For example, a piston pump with rotatable pistons can be equipped with a suspension ("hanger") for changing the stroke of the pistons The device for changing the delivery rate usually also contains a movable element, the position of which controls the • fluid displacement, for example by changing the angular position of a wobble plate attached to a suspension or by changing the eccentricity of a cam ring s determined.

Means for varying the displacement can be in two groups, in which are classified naoh one side and the working to both sides _e In the devices, the one side NaOH adjust out the amount of liquid can

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can be changed between zero and a maximum value. In the devices regulating to both sides, the displacement of a mean flow in one direction to zero and in the opposite direction adjusted to a maximum value will. The reference to the mean value in the identification of the two groups of adjustment devices results from the fact that the change in the displacement in the first group takes place in that the device causing this process is itself moved within a range of positions on either side of the axis or the center of the device while In the case mentioned in the second place, the adjustment device moves from one end of an adjustment range via the middle one Adjustment can be adjusted to the opposite side of the control range.

A liquid pump or a liquid motor or the like. Machine, which works with variable displacement, has a movable control element, the position of which determines the stroke length of the piston or of the corresponding machine part according to the invention, the position of the movable control element by a Piston is determined, which is set up for adjusting the control element and which is dependent on the fluid pressure moves in the cylinder, the liquid flow is controlled by a valve, the valve body on a Side is spring-loaded and acts on the opposite side of a fluid pressure that is equal or proportionate is the pressure generated by the pump or delivered to the engine, the piston with one to one Control thumb adjacent cam surface is equipped in such a way, that the control thumb moves with the movement of the piston and this movement provides the force by which the valve element against the present, to be controlled fluid pressure is held and this force acting on the valve element through the

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Seeks to balance the force exerted by the fluid pressure.

In this way the torque required to drive the pump can be achieved limited or regulated so that a preset value cannot be exceeded. Since the drive power for a pump for the product of the amount of liquid delivered and the pressure ratio is the same, if the pump runs at a constant speed, it is possible according to the .Erfindung the torque to limit or regulate when the pump is running at a constant speed. When applying the invention to a Liquid motor it is possible to adjust the output torque of the To keep the motor constant.

This is necessary because, for example, when a Pump is driven by a 10 HP electric boron and its operating speed is chosen so that it conveys a certain amount oei, for example, 2w3tf ifco square inches and the pump pQö ocial should generate a higher pressure, the operation of the pump with this higher pressure and the same volume displacement and speed can overload the motor driving the pump. According to the invention can the delivery rate of the pump can be adjusted to a lower value, so that the product of pressure and displacement on essentially remains the same value, which is a preset maximum torque and thus a certain power in horsepower so that the drive motor is not overloaded,

The pressure of the fluid acting on the valve is equal to or in proportion to the pressure in the fluid delivered by the pump Liquid or in the liquid supplied to the motor prevails. As soon as the fluid pressure begins to rise, there is the resilient device, preferably designed as a spring, and a force is exerted on the control thumb. Of the

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Control thumb is preferably set so that it increases or decreases the pressure of the spring. The valve body will therefore adjusted so that liquid enters the cylinder leading to the piston and the piston is actuated in such a way that the displacement adjusting device of the pump the displacement scaled down. The absorbed torque therefore remains essentially constant when the. Piston has moved enlarged the control thumb applies the spring pressure and closes the valve body again. When the pressure in the machine drops, the Resilient force acting on the valve body is greater than the pressure prevailing in the liquid and the valve body moves in such a way that the piston moves to the first v «& - it shifts in the opposite direction. The displacement of the This increases the machine and the torque absorbed remains essentially constant.

The displacement of the piston causes the control thumb to move in the direction in which the spring force is reduced. The valve therefore closes. From this it follows that the form the cam surface must be carefully calculated and preferably the torque curve of the pump, motor or the like. Machine corresponds. In many cases this is a hyperbolic curve.

Embodiments of the invention are given below with reference to Drawings explained in more detail.

It shows:

1 shows a section through a device for adjusting the displacement of a piston pump, which is equipped with a torque limiter, Fig. 2 is an enlarged partial view of the hydraulic Control mechanism for the torque limiter according to Fig. 1,

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Pig 3 through a sonity, a torque regulator,

which works in both adjustment directions and is attached to a pump or motor,

! ig. 4 a son through the pistol like him

is provided in the arrangement according to FIG. 3 and

Fig. 5 is a complete representation of a device operating with pressure fluid, in which a Regulating device of the type shown in Pig · 3, working in both directions of adjustment is provided.

The pump or motor is generally shown in Figs

21 marked · To simplify the illustration, the machine hereinafter referred to as the pump. It consists of a housing

22 with a chamber 23 located therein. Inside the chamber

23 is a bearing 24 for a cylinder liner 26 · The liner 26 is rotatable in the bearing 24 and at 30 non-rotatably connected to a drive shaft 27 by means of splines. In the cylinder liner are in Circular and parallel to one another parallel bores or cylinders 28 are provided, in which pistons 29 can be displaced.

Between the end of the cylinder liner 26 on the left in the drawing and the head 39 of the housing 22 is a valve plate 32 having a liquid inlet port 33 and a liquid outlet port 34 arranged. The inlet opening 33 is connected to the suction line of the pump 21 in the head 31. The suction opening is denoted by 36. A pipe 37 leads from the opening 36 to a fluid storage container, which is indicated by 38 in FIG is. The opening 34 in the valve plate 32 is aligned with the pump outlet side or the pressure-side opening 39 in connection, the is provided in the head piece 31. A pipe 41 leads from the opening 39 to the hydraulic system or machine (not shown), wherein a conventional pressure relief valve 42 is installed in the line

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is. The pressure relief valve 42 is provided with a relief line 43 which leads back the excess liquid to the container 38. The pipe 44 is also connected to the pipe 41 and thus to the pressure opening 39. The purpose of the line 44 is to will be explained in more detail later.

The cylinders 28 in the cylinder liner 26 have openings in connection, which in turn with rotation of the sleeve 26 successively with the inlet port 33 and the outlet port 34 in the Valve plate 32 come into connection. The pistons 29, which are movable back and forth in the cylinders 28, are movable on all sides Joints connected to shoes (in the figure reohts), which are supported on a swash plate 46. The swash plate 46 is connected to the device adjusting the displacement. This device consists of a suspension or fork 51 which is pivotable in pin (not shown) about an axis which - runs perpendicular to the plane of the drawing. This allows the angular position the plate 46 can be changed relative to the axis of the drive shaft 27 »

When the drive shaft 27 from a (not shown) drive motor is set in rotation, the pistons 29 go due to the action of the plate 46 in their cylinders 28 when the Sleeve 26 back and forth. In this case, liquid is sucked in from the storage container 38 via the line 37, which liquid passes through the opening 33 in the valve plate 32 enters the cylinder 28 »When the cylinder liner 26 rotates, the liquid is removed from the piston in turn displaced and ejected through the opening 34 when the piston, based on the drawing, to the left through the the plate 46 abutting shoes are moved.

The suspension 51 is provided with a central opening 52 and a rear cross arm 53 is provided. A holding part 54 is in the middle

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». 7 -

Opening 52 attaches and holds an upper wheel 56 on a dwell 57 and a lower wheel 58 on a transverse shaft b9. That Had. 56 protrudes near the top over the suspension 51 and the wheel 58 protrudes in a corresponding manner downwards over the suspension.

The suspension 51 is housed in a G-ehäuse 61 connected to the outer housing 52 of the device and at its right end duroh a lid 62 is closed ₀

When the suspension 51 is in its central or neutral position, i.e. when its center line is parallel to the axis of the shaft 27, the swash plate 46 is perpendicular to the shaft 27. In this position, the pistons 29 are not moved back and forth when the sleeve 26 is rotated and no liquid is conveyed. When the angular position of the plate 46 and the suspension 51 is changed in that the suspension 51 is moved from its zero position, the displacement of the piston takes with it the as * · increasing stroke movement of the pistons 29 during rotation the sleeve 26 too.

The greatest liquid displacement is determined by a stop 63 which is arranged on the cross arm 3 of the suspension. This stop comes to rest on the inside of the housing b1 and prevents the suspension!? 1 from moving further into the Displacement increasing. Moving direction. The! Pump 21 is only adjustable after a direction, i.e. the suspension t) 1 can be, starting from its middle position, only move in one direction

The suspension is pressed in the direction of adjustment, in which the displacement increases wildly, with the aid of a spring-loaded piston ba which presses against the lower roller 5U under suspension. The piston b6 consists of a vertically arranged plunger 67,

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at the end of an enlarged head 68 is attached, on which the oolle 58 when the suspension 51 is adjusted in its bearing pin unrolls. The shaft part 69 of the tappet 67, which is smaller in diameter, can be displaced in a bore 70 in a guide piece 71. At the lower end of the guide piece 71 is a cap 72 screwed on, which is attached to the side of the housing 61.

The guide piece 61 is provided with a transverse slot 73 running in the longitudinal direction, which intersects the bore 70. By A transverse pin 74, which engages in the slot 73, passes the plunger 67 and moves up and down in this when the plunger 67 moves in the bore 70 and one rotation of the plunger 67 prevented around its axis. A spring 67 surrounding the guide piece 71 pushes the plunger 67 upwards into contact with the roller 58, whereby the suspension 51 is pivoted in the direction corresponding to an increase in the displacement. The agility of the Suspension 51 in the opposite direction, i.e. towards the zero position, is limited by the fact that the head 68 of the ram 67 runs onto the upper end of the guide piece 71. This happens, when the suspension is in the neutral position. The suspension cannot move beyond the middle position.

A drainage bore 78 extends from the bore 70, so that no liquid is enclosed in the bore, if the plunger 67 moves downwards. The bore 70 is also in the axial direction with a smaller diameter bore 79 in Connection, which in turn merges into a larger axial bore 81, which is also provided in the guide piece 71. The hole 81 is square in cross-section and leads the square Shaft part 82 of an adjusting device 83. The adjusting device 83 has a square head 84 on the outside on, which protrudes outwardly from the pump and to which a cylindrical section 86 of enlarged diameter is connected,

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The cylindrical portion 86 fits into a bore in the cover 72 and is equipped with a groove 87 in which an O ~ ring is located as a liquid-tight seal against the cover 72. One The locking nut 88 is screwed onto the cover 72 from the outside and engages over the cylindrical section 86. The head 84 of the adjusting device 83 stands through the central opening of the nut outward. When the assembly is tightened, the inner surface of lock nut 88 abuts portion 86 and presses it against the cover 72 so that the adjusting device 83 cannot be rotated.

With the help of the adjustment device, it is possible to adjust the position in which the plunger head 68 strikes the top of the guide piece 71, to be regulated in such a way that the zero position of the suspension changes.

As has thus been described, the mechanism on one side, i.e. on the lower side of the pump 21, as shown in Fig is shown, a resilient elastic force that the suspension 51 seeks to move in the direction corresponding to an increase in displacement. A controlled force that controls the suspension seeks to adjust in the opposite direction to this force is supplied by a hydraulic control device, which is generally designated 91 and which is arranged on the opposite side of the pump from the device 66 is.

The hydraulic control device 91 consists of a displacement controlling piston or a torque-limiting piston 92, which is coaxial with the plunger 67 on the opposite Side of the pump is arranged. The piston 92 is hydraulically operated to drive the displacement changing device of the pump 21, i.e. around the angular position of the suspension 51 in relation to and in inverse proportion to that of the pump 21

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- ίο -

to adjust or change the pressure delivered to the opening 39, so that the torque absorbed by the pump is reduced to a predetermined value Maximum value "remains limited. In detail, this means that when the pressure delivered by the pump 21 tends to do so or begins to increase while the device is at the stop

63 is present, uich. also the product of printing and

confused
and the pump draws more power from the engine. When the predetermined maximum value has been reached, the piston 92 moves automatically downwards by means to be described later, so that the suspension 51 is adjusted in the direction corresponding to a reduction in the displacement and thereby the volume of the liquid delivered by the pump decreases, with Simultaneously and proportionally, reduce both the input torque and the drive power consumed if it is assumed that the pump is operated at constant speed of repression

A block-shaped housing 93 is on the side of the housing 61 over a Opening 94 attached. The lower end of the housing 93 protrudes into the opening 94. This block-like housing 93 is with a horizontally extending bore 96 equipped, in which a cylindrical Bush 97 is fitted. A sealing ring 100 arranged between the two housings ensures a liquid-tight seal Termination at the junction.

In the bush 97, a piston 92 is guided coaxially with the plunger 67. The piston, the top of which is designated by 98, is provided with thread 99 at its lower end. One with a corresponding Externally threaded rod 101, which at its end forms a relatively large flat head 102, is in the

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screwed in lower opening 99 of the piston and through a lock nut 103 additionally fortified

The piston 92 is cut out on one side to form a corner surface 105. The aspects to be observed when shaping this cam surface 105 will be explained in detail below. A horizontal transverse bore 106 is provided in the housing 93. It goes through the sleeve 97 and opens into the bore in which the piston 92 slides at a point opposite the curl surface 105 _{or the like}

A substantially L-shaped housing part 107 is attached to the side of the housing 93 and forms on its inner side a cylindrical extension 108 which fits into the bore 106, iline horizontal bore 111 is provided in the part 107, which is aligned with the bore 106 and with this is in connection _β iüin. Einschnitt 112 cuts the bore 111 in part 107 and an outwardly protruding projection 113 above the cutout 112 forms a pivot bearing for a pivotable lever, as will be explained c

A cam-controlled piston 114 is movable in the bore 111 of the part 107. This piston 114 is equipped at its inner end with two eyelets 117 arranged at a distance from one another, between which a roller 118 is rotatably mounted. The ttolle abuts the side of the piston 92 at the h ockenflache 105th The piston 114 is equipped with a vertically arranged pin 119 which engages in the cutout 112 and thereby holds the axis about which the roller 118 rotates in a horizontal position. An internal thread is provided on the outer end of the piston 114, into which an adjusting screw 121 engages. The screw has a flat enlarged head 122. The screw 121 is fixed in the longitudinal direction on the piston 114 with the aid of a locking nut 123.

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A pivot lever 126 is mounted about a transverse axis 127 on a projection 113 on the part 107. The pivot lever 126 is provided with a rotatable roller 128 at its lower end and a rotatable roller 129 at its upper end. The roller 128 rests on the head 122 of the adjusting screw 121, which in turn is fastened to the cylinder 114. From FIG. 1 it follows that when the control piston 92 moves downwards from the position shown, the trowel 118 and the tappet 114 due to the inclination of the corner surface 10b outwards from the bore 111, d _o h _o based on the drawing is slid to the left. When this occurs, the pivot lever 126 rotates clockwise about its pivot bearing 127, whereby the roller 129 at the upper end of the pivot lever, again based on the drawing, shifted to the right

An actuating or control mechanism is accommodated in an upper housing part 131 on the flat surface of the housing part 93. The upper housing part 131 has a horizontal bore 132, whose right is lying ünde .angeschlossen to the line 44, which in turn irijt ^r ier output port 39 of the pump 21 is in communication. The Bohruig 132 in the upper part 131 is offset. The larger diameter part 133 is located at the left end of the bore. A bushing 13, which is shown enlarged in FIG. 2, is guided in the bore 132 with a tight seal.

The sleeve 135 is cylindrical and has shoulders _o An axial boning 1 ^ b starts from its end located on the right in the drawing and leads to an axial bore 137 with a narrower diameter. On the left Jäade 138, the sleeve is reduced in diameter. A .Nut 140 extends circumferentially around the sleeve 135 "Kadial arranged openings 141 provide a connection between the groove 140 and the inner bore of the sleeve 135 in I36 h.er ₉ A as Ü ^ ing formed sealing ring I3y's

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Proposed near the bottom of the sleeve 155 lying on the ground. One .Spring clamp 142 encompasses the bushing 155 to the left of the groove 140. The spring clip 142 rests on the shoulder in hole 1 ^ 2 in the tfehäueeteil 151 (see Fig. 1) ', i.e., where the in diameter larger part 155 of the hole in the smaller one in diameter Part 132 passes over. A radio bore 145 in the rifle 155 connects the inner bore 156 to the enlarged diameter part 153 of the bore in the upper housing part 151.

Its substantially cylindrical guide 146 is partially in the enlarged bracket 155 screwed in. It forms one Inner chamber 147. The inner end of the guide 146 is located on the outer shoulder 148 of the sleeve 155 (see Fig. 2) and stops 4 with the spring clip 142 on the shoulder in the bore 152.

As Bioh best shows from Pig, 2, is a slide valve 151 in the bore 156 of the Büohse 155 slidably guided Sin Kopfetüok 152, whose dimension in the axial direction is the width of the openings 141 corresponds to is at the right-hand end of the piston sole upper 151 formed by attaching a circumferential groove 155 © A Groove 154 running in the longitudinal direction is provided on the end part 155 of the piston slide 151 arranged on the left. The openings 145 of the Büohse 135 stand with the space 156, which is at the groove 155 is formed, in connection,

A piston 158 is sealing and slidable in a bore 159 of a guide piece 156 guided coaxially to the piston valve 151. The roller 129 of the pivot lever 126 rests on the outer surface of the piston 158. A spring 160 surrounds the one on the right End of the piston 158 and is supported with its other end on a centering piece 161 mounted on a ball, which is shown in the chamber 147 of the guide piece 146 is movable. the piece 162 is in its right-hand end face with a

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concave cavity and rests on a ball 162, which in turn is supported on the end of the piston valve 151.

Two vertical bores intersect the bores 132 and 133 in the upper part 131. One of these bores, which is denoted by 164, is connected to the groove 140 on the sleeve 135 and, at its lower part, leads into the interior of the sleeve 97. gen housing part 93. the other of these bores is indicated by 165, is from the openings 145 in the BÜchße 135 and passes through the housing part 93 to the transverse bore 106. another bore 166 communicates the bore 106 with the chamber 23 in the housing 61 the pump. This chamber 63 is in turn connected to an outlet opening 168 in the pump housing 22 leading to the storage container. A line 169 leads from the outlet opening to the storage container 38.

It is now the mode of action in one direction in your Displacement adjustable pump with torque limitation on the basis of FIGS. 1 and 2 explained. The pump is through line 37 fed with liquid from the container 38 and conveys liquid under pressure into the line 41 · At every angular position of the The suspension 51 and the plate 46 is the volume of liquid displaced by the piston 29 in a single revolution of the sleeve 26 essentially constant. At a constant speed and with a constant setting of the suspension as well as at a given one The starting point of the pump is thus essentially constant on the drive shaft 27 to which the motor is connected Torque required. However, if the pressure in line 41 changes due to a change in pump load, seek to change the absorbed torque proportionally. The hydraulic control device 91 provides such pressure changes firmly and responds to them immediately in such a way that the pump displacement displaces in the opposite sense to the pressure change.

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is, so that the product of pressure and displacement in the is kept essentially constant.

It should first be assumed that the pump is operated "with the setting of the suspension Ά ^{shown in FIG. 1} Ig. 1" and that the pressure in the line 41 begins to rise " is large that the pressure relief valve 42 responds, so no superfluous liquid flows off at the valve 42.

under these conditions the pressure is reflected in the line 44 the fluid pressure in ctur line 41, since the two lines are connected to each other. The pressure acts via the line 44 in the bore 132 of the upper housing part 131 of the hyi ^ riulischen Control device 91 off. The pressure passes through the hole 137 with a small diameter into the hole 136 and strikes the right end face 157 of the oil control piston 151. The piston is displaced to the left by the force of the spring 160 and opens the normally closed openings 141 for the liquid located in the bore 136. Hydraulic fluid in the Bore 132 thus flows through the .bohrung 137 and 136 through the Openings 141 to the annular groove 140 and through the bore 164 to Chamber 171, which is above the upper end face 98 of the control piston 92 lies. The pressure of this fluid is enough to handle all of the Movement of the suspension including the force of the mechanism 66 to overcome opposing forces and the control piston 92 moves down in the sleeve 97, the suspension 51 and the swash plate 46 in the sense of reducing the displacement adjusted. The delivery rate ddr pump is thus reduced.

When the control piston 92 moves down, the hell rolls 118 on the cam surface 105 of the control piston 92. Vie according to FIG. 1

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As can be seen, the inclination or curvature of the Itfockehflache 105 during the downward movement of the piston 92 from the position shown causes the plunger 114 to be displaced outwards, ie to the left in relation to the drawing. As a result, the hollow 128 on the pivot lever 126, which rests on the screw 121, is moved outward, so that the hollow 129 on the other linden of the pivot lever 126 is displaced to the right. The hollow 129 rests on the outer unde of the piston 150, which moves in the bore 159 of the guide piece 146. When the roller 129 pushes the piston 158 to the right, the compression of the spring 160 is increased so that the spring force directed to the right on the piston slide 151, which works against the fluid pressure acting on the right end face 157, is increased. When the spring force balances the fluid pressure and when the head piece 152 is about to close the openings 151 in the sleeve i'-j'j, v / ie shown in FIG. 2, the flow of fluid through the bore 164 to the chamber 171 above oteuerkolbens 92 and the control piston 32 remains in its siöien position. As a result, the suspension 5I no longer changes its position and the amount of liquid delivered per revolution by the pump remains constant until the pressure changes again ₀

nenn the liquid pressure in line 4I drops »decreases aie act on the right end face 15 / of the spool 15I Force in relation to the force of the spring 160 and the spring moves the slide to the right, with the openings I4I open to chamber 156 surrounding i \ iut 153. This results in a connection between the openings 145 and I4I. the Openings 145 are above the stanchions 153, 165 »106 and 166 and the opening 94 with the chamber 23 in the housing 61 in communication. the As previously mentioned, the chamber is connected to the container 58 via the line 1b9. i) s is therefore the one above piston 92 Pressure fluid through the bore 164, the hat 140, the uff-

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BAD ORfQiNAL

mangle 141 and through chamber 156 to chamber 23 to the container derived. The force of the spring 76 of the device 66 presses the suspension 51 in the direction increasing the displacement. While moving the suspension in this direction, the Piston 92 pushed close to the top, especially since the pressure fluid acting downwards on piston 92 to the reservoir, as described is relieved.

When the piston 92 has been moved up, it shifts the roller 118 near the right and follows the cam surface 105 on the ground the force of the spring 160 acting on it. When the cylinder 114 moved near to the right, the compression of the spring decreases from, so that the acting on the piston valve 151 to the right Spring force also reduced. Liquid is drained from the chamber 71 above the piston 92 and the piston 92 continues its Movement near the top continues until the spring force on the piston valve 151 by the hydraulic force on his right Jiside I57 acts, balance each other and the head piece 152 the openings 141 locks. Under these conditions is the one above of the piston 92 located liquid. completed and the Control piston 92 remains in its position. The pump therefore delivers a constant amount of liquid per revolution, when there is another change in the pump pressure.

The control piston 92 moves under stable operating conditions a displacement that maintains a fluid pressure just sufficient to force the header 152 into the openings 141 in a closed position, so that the liquid neither enters the chamber 171 above the control piston 92 still flows out of it when the pressure differs from that which is required to hold the head piece 152 in the indicated position, the head piece 152 moves in one or the opposite charge either under the effect

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the fluid pressure. The head piece also changes the position of the control piston 52 and the suspension 51 at the same time, so that the pump displacement is adjusted in the opposite direction and the pump continues to run with constant torque absorption O -

From the above it follows that the displacement the pump is controlled by the piston 92 and that the piston 92 in turn regulates the compression of the spring 160, which in turn determines the fluid pressure in line 44, which is used to change the position of the suspension 51. The shape of the squatting surface 105 determines the fluid pressure j that for moving the spool 151 at any specified suspension setting continued * = i4cÄ, -Jjst. Form, the ÜTockenflache 105 is determined mathematically and is similar to one rectangular hyperbola: each through the cam surface 105-. horizontal plane that goes through corresponds to a different displacement and corresponds to every vertical plane that goes through the flat surface a different fluid pressure. The iTock surface is shaped so that the product of the displacement that results from the "perpendicular" Coordinate of a point on the cam surface, and the pressure yields that of the horizontal coordinates of the same point, represents a constant that is proportional to the pump output and therefore also proportionally the same as the pump input is β - .. = ■■

The head 102 on the stop 101 of the control piston 92 is vertical Direction to the piston adjustable, so that "the height position of the ITockenf lache -105 compared to the suspension 51 can be changed can. With the help of this adjustment, the specific torque limit, which is maintained by the torque limiting device can be changed within a certain range. The screw 121 can also in relation to

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Cam surface 105 can be adjusted, so that the pressure at the "I ^l eder 160" can be adjusted for the best adaptation to the respective pump in which the control device 91 is installed.

Tests have shown that the with the inventive Control-equipped pump required torque largely approximating the specified v / ert remains. the Deviations from this specified value do not change noticeably when the torque changes »One with a constant Speed running pump can, for example, with a corner surface 105 specifically designed for, for example, 40 horsepower is provided. Nevertheless, the control device can be essentially equally effective at values between 20 and 50 horsepower can be set.

The Pig. 1 and 2 explain the principle of the invention on the basis of a The pump can only be adjusted on one side. 3, 4 and 5 show a mechanism according to another embodiment of the invention, in which the required torque at an in both adjustment directions adjustable pump is kept at a constant value.

In the case of the pump according to FIG. 1, which can only be adjusted to one side, the movement of the suspension 51 in the direction reducing the displacement is limited by a stop, so that the suspension cannot move beyond the central position, in which essentially no i ''Liquid is conveyed by the pump and in which the plane of the wobble plate 46 is perpendicular to the axis of the shaft 27. With pumps of the so-called type that can be regulated on both sides, the mobility of the suspension is not limited to one side, starting from the central position, but the suspension can move from one side of the fluid position to one position on the other page

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ORIGINAL

If this takes place, the direction of flow in the pump changes, although the direction of flow on the shaft 27 remains the same.

Pumps which can be regulated beyond the middle position are known per se and do not need to be explained in more detail «,

In FIG. 3, the device 51 'controlling the displacement is shown. Similar to the suspension 51 in the example of FIG. 1, the suspension 51 'with an upper hollow 56 =' and a lower holle 58 'equipped. The suspension 51 is in Housed inside a housing 61 ', only parts of which are shown sindo The other details of about the middle position adjustable pumps can be conventional.

At diametrically opposite ends of the housing 61 ' are hydraulically operating control devices .. 176 and 177

the ^:

seen / limit the torque absorbed. The facilities 17o and 177 are designed and controlled in agreement with one another the suspension 51 'on each side, based on the middle position. Since the two devices 176 and 177 are designed the same it is sufficient to describe the upper mechanism 177 in detail to explain »

The device 177 consists of a hollow cylinder block 178 which is fastened to the housing 61 'and is sealed against it is. The cylinder block 178 projects into the chamber 23 'through an opening in the housing. Inside the cylinder block 178 is one large upper bore 179 in diameter and an equiaxed, Lower bore 180 smaller in diameter is provided. A Piston 183 is slidable and sealed in bore 180 of block 178. The piston 183 lies with its lower Front side 184 on the upper hulk 56 'of the suspension 51 on "Eine

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Opening 185 goes through block 178 and is in line with the Hole 179 in connection «A conduit 186 is connected to the opening 185 connected

Attached to the top of block 178 is a device 188 which in several respects is similar to the hydraulic control 91 of the pump shown in Pig * 1. The essential difference between the device 188 according to Mg ₀ 3 and the device 91 according to Mg ₀ 1 consists in the different design of the covers 189 and 131.

The device 188 consists of a cylindrical part 191 » in which a control piston or a piston to limit the absorbed Torque 192 is performed. An adjustable stop 193 is screwed into the bottom of the control piston 192. The stop 193 has a head 195 which is inserted into the bore 179 of block 178 protrudes. The position of the head 195 can be adjusted by means of the stop 193 in relation to the piston 192 » On the control piston 192 there is a cam surface 196 on one side Side provided that the squatting surface 105 of the piston 92 in ! ig. 1 was similar to a RoUe 199 lying on the cam surface mounted on a plunger 220 displaceable in a horizontal direction ·

A collector 201 at one end of a pivot lever 202 rests on the iäide of the plunger 200 and pivots the pivot arm 202 about a joint 203 under the influence of the movement of the plunger 20O ₀

The upper housing part 189 is shown separately in FIG. 4 Upper housing part 189 consists of a body 206 through which a horizontal bore 207 passes. The hole 207 is on one end-into a smaller diameter hole, 208 across, A sleeve 209 is arranged axially fixed in the bore 207. the

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Sleeve 209 is provided with an axial bore 210 and has three circumferential grooves 211, 212 and 213 on the outside, which are in axial Distances next to each other. Jtiadialöffnungse-n 215 connect the hat 211 with the axial bore 210, further openings 216 provide a connection between the groove 212 and the bore

210 and other openings 217 lead from the hat 213 into the bore 210o. O-ring seals are on both sides of hats 211 and 212 provided a vertical hole 220 passes through the housing part 206 and connects the cap 212 of the sleeve 209 with the chamber 221 in the cylindrical part 191 above the piston 192. The openings 224 and 225 go through the housing part 206 to the grooves 211 and 21-3o

The piston slide 227 is sealed and slidable in the bore 210 of the sleeve 209. The piston valve 227 has three sections 228, 229 '230, in which it has full diameter _o of the central portion 229 has an inner diameter which corresponds to the axial spacing of the openings 216 "A hat 231 separating the sections 228 and 229 from each other and another hat 232 lies between sections 229 and 230. A threaded connection 233 is provided at the right end of the bore 210

The piston 234 is arranged displaceably and guided in a sealed manner in the bore 208 of the upper housing part 206. A spring 235 is urged by the piston 234 against a shoulder provided at the left end of the slide 227. The piston is located in a wool 236 on the upper junction of the pivot lever 202 on _e

The housing part 178 of the upper part 177 is between the bores 179 and 180 equipped with a shoulder 237. Above this shoulder 237 there is an annular disc 238 in the bore moveable. The disk 238 is raised in the middle 239, two diagonally extending bores 240 a fluid connection

90 983 8/02 54

through disk 238 to bore 179 and 1ξ} 0 ". One or several springs 242 presses on an inner shoulder 243 on the one below Surface of the cylindrical · part 191 "and presses the disc 238 down against the lower shoulder 237ο

i'ig. b shows a diagram of the hydraulic system from one of the coat position on both sides is adjustable pump with the control device according to the invention according to i'ig · 3 and 4 equipped istc In Pig. 5 the pump is indicated with 245. the The pump has a pressure opening 246 on one side and a further opening 247 on the opposite side. Depending on the position of the suspension 51 'on the pump 245 is one of the openings 246 and 247 »a constant direction of rotation Pump drive shaft provided the inlet ports, while the other port forms the pressure port. When the suspension 51 * is adjusted beyond the middle position, the direction of flow of the medium 245 to be pumped is reversed.

The port 246 of the pump 245 is connected to a line 248 which is in communication with the hydraulic system (not shown) and which is intended to be driven by the pump. A two Y / ege pressure relief valve 249 is also connected to one side of the control device . The two mega- or double-acting pressure relief valve 249 can be of conventional design and has two openings and a valve body between these openings, which opens in the event of excessive pressure at one of the two openings and thereby allows excess liquid to flow to the other opening.

The other port 247 of the pump 245 is connected to a line 250, that of the hydraulic machine to be driven by the pump (not shown) goes. The line 250 is also connected to the second opening of the two-way overload valve 249.

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When the pump 245 is operating, pressure fluid is passed through, provided that the opening 246 is the output side on the pressure side, the line 248 promoted to the work machine. The excess pressure fluid, which is discharged at the pressure relief valve 249, is brought to line 250 via valve 249 and returns from there to inlet port 247 via line 250 Line 247 represents the pressure opening, the excess liquid is discharged from the overload valve 249 to line 248 and comes to the pump opening 246, which under these conditions represents the suction opening.

As explained in more detail below, the torque limiter uses according to Pig »3 a separate pressure fluid source during operation and thus differs from the devices according to the Pig. 1 and 3 «In the system according to FIG Working pressure fluid conveyed by a small pump 253 from a '^ ank 254 and via a pressure relief valve 255 into the line 256 given. Excess fluid is returned to reservoir 254 in valve 255

The line 256 is connected to the opening 225 on the upper part of the housing of the upper control device 177 via a line 257. Similarly, line 256 of pump 253 and port 225-0 of lower controller 176 are via one Line 258 connected. The opening 224 of the upper control device 177 communicates with the opening 224-0 of the lower control device 126 and the container 254 via lines 259 and 260 in connection.

Am electromagnetically actuated, in the middle position by spring force The four-way valve held is graphically entered at 252. The valve 252 has four ports 261, 262, 263 and 264 and a valve body with three different positions

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can take. All of them are in the middle position of the valve body four connections 261 "to 264 in connection with one another. In the The position in which the valve body is shown diagrammatically in FIG. 5 is the connection 262 with the connection 263 and the Terminal 264 connected to terminal 2b1. In the third position of the valve body, the connection 262 is with the connection 264 and the connection 263 with the connection 261 in connection. The position of the valve body is controlled by electromagnets 278 and 279 controlled at the opposite ends. Such four-way valves are "known and do not need to be described further to become"

The connection 262 of the four-way valve 252 is connected to the line 257 via a line 265. The connection 263 of the Valve 25.2 is connected to line 186, which in turn led to opening 185 in upper control device 177 Connection 264 is via a line 26b with the opening 185-0 the lower control device for limiting the torque 176 in connection. The connection 261 is to the storage tank leading line 260 connected ,, *

The opening 246 of the pump 245 is through a line 267 to the opening 263 of the upper housing part 189 of the overhead control mechanism 177 connected. Similarly, a conduit 268 connects the corresponding port 233x0 to the port on the opposite side of the pump 245.

Supplementary fluid tangled: the main pump system from the line 256 supplied to the auxiliary pump 253 through a pressure reducing valve 270, which is in communication with line 256 through line 271. The pressure reducing valve 270 may be of a known suitable type Be construction. The liquid goes through the pressure reducing valve 270 to a line 272 in which the valve 270 a

909838/0254

maintains slightly increased pressure, for example 15 pounds per square inch above atmospheric pressure. The pressure reducing valve 270 is equipped with a line 273 leading to the container, which is connected to line 260 «

The line 273 coming from the pressure reducing valve is via a check valve 275, which allows liquid to pass in the direction of valve 270, is connected to line 250. Line 272 is via a second check valve 276 with the line 248 in connection. The check valve 276 lets liquid off the line 272 to line 248, but not in the opposite direction.

The four-way valve 252 can be operated manually or automatically in order to move the suspension 51 ′ past the center position of the pump 245. In the position of the suspension 51 'shown in FIG. 3, it should be assumed that the pump 245 conveys pressure fluid to the opening 247 and that the opening 246 forms the pump inlet. Under these conditions, the "four-way valve 252 is operated so that the line connections manner shown 5 are made as shown in Fig.. The hydraulic fluid supplied by the Hirsch pump 253 to the line 256 is therefore through the four-way valve 252 from line 275 to line 186 and brought through the opening 185 into the bore 179 under the control piston 192. Pressure fluid from the line 257 is also conveyed to the opening 225 on the upper part 189 of the upper control device 177. This fluid enters the hat 213 and passes through the openings 217 into the room in the bore 210, which surrounds the groove 232 of the slide 227. Since the opening 246 forms the pump inlet opening under these conditions, the pressure in the line 267 is low, and this low pressure is also expressed

909838/025 A

at the opening 253 and in the bore 210 and to the right of the full-diameter part 230 of the slide 227.

Under these conditions, hydraulic fluid also comes from the line 256 and line 258 to the opening 225-0 of the lower, the torque limiting control device 176. The in the The fluid pressure present in line 258 acts on the space through the to the right of the full diameter part 230-0! Line 268 "The opening 185-0 of the assembly 176 is via the Four-way valve 252 and lines 266 and 260 with the container 254 connected.

The pressure supplied by the pump 254 flows through the line 268 to the right-hand end face 277-C of the piston valve 227-0 in the lower control device 17C '.che 19C-C and the articulated lever arrangement cooperating with the pivot lever bertim:.: t wircL For example, if the pressure supplied by the pump 245 begins to increase, the piston valve 227-C moves to the left and the openings 21G-O are from the full DruciimesEer a υ.Γ; ν iron part 229-0 released DruckfiüPfcd & keit then flies from the opening 225-C i.nr/äer line 2.Z ^ uui-cL. uie ^ chrung 223 in the ii ^ urc. 221-0 uirfcc:. El oil »piston 192-C. You before. 1: r Druu :: f l '.' Scigkeit developed force outweighs the lesser force which the pressure in the Ichi-ari ^ 1QC ar, Selben 133 produces, v / eil the Bchrang in the cross scarf Ά ^V 2 one never of the Holten 13 - C is. ', "As the piston 132-0 moves upwards under the effect of the equalized forces, the connector 193-0 ge {: en the disk 238-0, which in turn moves the piston 1" ^: 3-C according to cbc :. lacks. This will

909838 / 025A

BAD ORiQiNAL

the suspension 51 ¹ in. Adjusted the delivery rate reducing sense. The upward movement of the piston 192-0 continues until the force exerted by the spring 235-0 is exactly balanced by the force exerted by the fluid pressure on the surface 277-0 of the slide 227-0, and the thickened slide part 229 -0 covers the openings 216-0. The shape of the jib surface 196-0 is "selected * as has already been described above, that the process mentioned takes place with a set displacement in which the product of displacement and pressure is that required by the pump Liquid is essentially at a constant value. As with the torque setting, which can only be adjusted in one direction, the torque maintained by the mechanism described can be adjusted by changing the stops 193, 193-0 and by adjusting the pistons 200 and 200-0, which, if this is desired, are also in their Length can be adjustable, be set ^ It is pointed out ^ that the last described embodiment can be set to different torques on the two sides of the middle position. .

We & n with the suspension 51 '»in the lower position as this is indicated in FIG. 3, the pressure of the output from the pump If the liquid sinks and the torque required to drive the pump is therefore also smaller, the pressure on the surface increases 277-0 from the hydraulic force acting on the piston valve 227-0 and the spring '237-0 "moves the valve 227-0 to the right * This creates a line connection between the chamber 221-0 the basket 192-Ö and the storage container 254 through the opening -0 established, · 'When this happens> moves the pressure acting on the opposite or top surface of piston 192-0, the. is generated by the auxiliary pump 253 through the port 185-0, the Piston 192-0 down. "This reduces the compression

BATH ORIGINAL

the! spring 235-0, until the force exerted by the pe is just off the hydraulic force acting on the slide surface 277-0 is balanced and the one with a thicker cross-section Part 229-0 of the slide closes the openings 216-0.

In Fig. 4, the balanced pressure state is shown in which the openings 216 are closed and the pressure of the liquid is exactly balanced on the surface 277 by the force of the spring 235. The liquid flows under these conditions neither in nor out of chamber 221 and piston 192 retains his position at.

As already explained above, the flow direction of the Liquid can be reversed by the pump 245 by adjusting the suspension 51 * beyond its center position, i.e. by Adjustment from the position appearing in Fig. 3 to the other Side of the center line. In the hydraulic shown in FIG This can be done by adjusting the four-way valve 252 in such a way that the connections to the lines 186 and 266 are interchanged, in the case of the electromagnetically actuated Valve, as it is shown in Fig. 5, the valve 252 or its electromagnet 258 on the left side of the assembly is energized and the electromagnet 279 on the right side remains unenergized. If, on the other hand, the electromagnet 279 is energized and the electromagnet 278 is de-energized, that which is present in the opening 262 acts Pressure expands at port 264 and propagates through line 266 to port 185-0 of lower controller 176, while the line 186 with the opening 261 of the storage container is connected. The operation of the electromagnet. 278 and 279 or the circuit of equivalent switching devices can either carried out manually or automatically according to a programmed sequence will.

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■ - 30 -;

If the torque limiter in the ELg. 3 location shown stands and the four-way valve 252 is operated so that the connections to openings 263 and 264 are reversed compared to the illustration port 185-0 is the lower controller 176 connected to the auxiliary pump 253 and the seal downwards "Fluid pressure acting on piston 183 is relieved, The piston 183 then moves under the action of that acting on the opposite piston 183-0 through the opening 185-0 Pressure down. The suspension 51 'moves here up or counterclockwise across the centerline of the pump 245. When this occurs, the through direction of flow of the pump and the hydraulic fluid occurs at the Port 246 from pump 245 out.

As can be seen from FIG. 5, this pressure acts via the line 267 at the opening 233 on the upper housing part 189 and acts against the raft of the spring 235. At the same time, the previously sinks onto the end face 277-0 of the piston valve 227-0 of the lower control device 176, pressure acts approximately on the tank pressure and the spring 235-0 moves the piston slide 227-0 to the right, whereby a line connection between the chamber 221-0 under the control piston 192-0 and the container through the opening 224-0 is generated. The lower control piston 192-0 is thereby moved in its bore down due to the forces acting on its upper surface ¹⁰ IUssigkeitsdrucks. This pressure is supplied through the opening 185-0. The piston 192-0 is no longer effective for adjusting the suspension. At the same time, the upper piston 192 takes over the adjustment of the suspension, since the pressure on the end face 277 of the upper piston valve 227 rises. The torque absorbed by the pump is thus kept at a constant value, as has been explained above. Under these terms

9098 38/0254

There is a stop connection between the lower one At the end of 195 of the attack 193Y the one with the tax collector 192 over the disk 238 is connected to the piston 183 »

To compensate for leakage losses in the system, for example can occur in the downstream hydraulic machine in the Pig arrangement. 5 ensures that additional! Liquid enters the main pump circuit regardless of the flow, direction can be fed by the pump 245. This supplement An initial liquid is fed in through a pressure reducing valve 277 ', which maintains a low pressure in line 272. This pressure is lower than the pump outlet pressure in the line 248 or 250, but it is greater than the pressure in the pump suction line. Therefore, if the line 248 is the pressure line represents, replenishment liquid is in the suction line 250 sucked in through the check valve 275 while the check valve 276 prevents the liquid from escaping from the Line 24T to escape · If the line 250 is the pressure line forms, the supplementary liquid is fed through the check valve 276.

It should be noted that the over the middle position in both Directional adjustable torque limitation from an auxiliary pump 253 is supplied with working pressure, as shown in the circuit diagram in Pig. 5 is to be removed, while the rule is only on one side. control device by the pump itself to be regulated delivered pressure is actuated. The pump 253 and the associated The control circuit is designed in such a way that the working pressure controls the pistons 192 tiTid 1-92-0 moved when the output from the pump 245 Pressure not Uuii-roicht ,. to bring about or. to adjust Achievement of the required mode of action is too low, like this

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OWQINAL

-52 - ■■ .. ^: ".

for example, the Pall can be when the. Suspension aioto. moved across the center line or if the pump is put into operation. , -.

All details described and shown are essential to the invention.

909 8 38/02

Claims (1)

PATENT CLAIMS J / Jlüseigkeitspuape or -motor with variable displacement "dl" is determined by "adjustable control element" which "regulates the piston stroke, characterized in that the position of the control element is influenced by an expensive piston, which is influenced by the in / Ien is acted druok _f $ ate the fluid flow through a valve g "r" g "according to whose valve body is spring-loaded on one side and is on the other side under liquid pressure produced the sound of the pump · - pistons leading cylinders ruling Flüssigkelt ·? or the fluid pressure supplied to the motor is equal to or equal to the ratio, the piston being equipped with a nose surface which rests on a control thumb, in such a way that the control thumb moves during the piston movement, this movement transmits the force which the valve body in the direction against the Keeping the fluid pressure changing and keeping the valve body in equilibrium with the pressure on it. 2 »Device according to claim 1, characterized in that the The valve body moves in the same direction as the pressure increases in which the piston moves through in the sense of a stroke adjustment the control element or a reduction in engine power is adjusted. 3 · Device according to claim 1 or 2, characterized in that dl · Nookenflacht on the piston one of the torque curve of the pump » of the motor or the like according to "has shape" 909838/0254 4 · Device according to claim 3, because it is known that the Let the cam surface on the piston be hyperbolic. 5 * Device according to the preceding claims, daduroh gekennseiohnetf that it contains a resilient βlastische binrichtung, which keeps the control element in contact with the piston . 6 · device according to the preceding claims, characterized in that the valve comprises a displaceable valve body demonstration ¹ normally located in a middle position "in de] of the piston leading cylinder is shut off, wherein the Ventilkäper by two Kiohtungen depending on" whether the fluid pressure to be regulated is greater or less than set "is movable and the valve body, when moved in one direction from its central position, brings the fluid pressure to the piston in the cylinder and the piston shifts in one direction" while moving of the valve body in the other direction, the same cylinder is relieved from its central position, so that the piston guided in it moves in the opposite direction mentioned above. , 7. Device naoh the preceding claims, characterized in that the resilient elastic bin direction consists of a spring, and that the control periods exerted by the peder · Force increased or decreased 8. Device naoh the preceding claims, characterized in that the fluid pressure acting on the valve body is used to move the piston iu _β * enh the valve body is in the opening position. 909838 / 025Λ BATH: -OWQlNAl. 9 «Torriohtung according to the previous claims, characterized in that devices are provided which differentiate the stroke length of the piston over the division ^ 'c. ^ S? Torques cu allow change « 10. Control device for use with an adjustable Displacement working liquid pump, a liquid motor or the like, in which a movable member is provided, which determines the displacement of the device by its position, characterized in that it enters the housing of the control device Piston is displaceably arranged, which is also displaced depending on the pressure device exit bearing on it and the device which adjusts the displacement, as well as being characterized in that a nook surface is arranged on the device and that a valve can be moved into a position in which liquid under bridging reaches the adjusting cylinder and the piston with the control thumb, which is resiliently resilient rests against the bottom surface of the piston, moves and exerts an elastic force on the valve body, which the valve in a Seeks to adjust the direction that is opposite to the fluid pressure, the shape of the cam surface is chosen so that the force exerted by the control thumb on the valve in Meaning an approximation of the value with which the liquid changes presses on the valve when the piston changes. 11. Liquid pump or motor or the like. With control working in both directions, old two Ansohluüöffnungen and one the displacement changing ^ lled, which is movable to change the displacement and the liquid flow between the openings, characterized in that it is equipped with a open control device according to claim 10, which are opposed to one another. 9098 38/0 25 U 14Nf448 opposite sides dee the displacement ver a dividing Gliedee arranged and connected so that "eowie characterized by means direct the liquid to the pressure prevailing at the openings * pressure to the" movable members of the control device, bo that verifiable as "movable member d in response to sound The pressure difference at the openings is also euoht. 909838 / 025A Blank page