DE1810184A1 - Hydraulic machine - Google Patents

Description

DR. ING / F. WUE ^- STHOFF ^% 8 MUNICH 00 DIPL. ING. G. PULSE eonWEIOEHSTHATE a DR.E.T.PEOHMANN. 'ncurox 22 00 81 DR. ING. D. BEHRENS 4 Θ- 1 ft 1 Θ / τ «ΜβηΑ« «Α» ΒΒββ »ι

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1-35 416

Description of the patent application

COUSIGKDIO MZIOITAIE DEILE RIOHERCHB, Rome, Italy

concerning
Hydraulic machine.

This invention relates to dynamic hydraulic machines and, more particularly, relates to hydraulic motors designed to operate smoothly at low speeds. More particularly, the invention relates to hydraulic motors commonly, but not exclusively, used in machine tools ₀ B. serve Z ', a controlled movement of a carriage, a working table, a rotatable turret or the like to bring about. "

Since längerei · time, it is common practice to place m of electric motors hydraulic motors to be used to machine tools various movements to create "Such hydraulic motors used v / in connection with a servo grounded; Apart from the fact that these motors work very smoothly at high speeds, they respond quickly and they work with a high dynamic stability, which is due to the high value of the ratio between the drive torque generated by them and the I / Iassenträgneit driven devices is due to ο

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However, to common Now hydraulic motors include relatively movable components that communicate with each other in frictional contact ₀ The re therebetween · * tively to each other movable components occurring friction "resistance increases" when the relative speed decreases until at very low speeds, the resistance a Assumes a value comparable to the value of the generated torque · Under these circumstances, changes in the frictional resistance, the occurrence of which cannot be avoided, become of considerable importance, since they lead to corresponding changes in the speed of the motor · These speed fluctuations that occur when a hydraulic motor is operated at a low speed, make it impossible to provide a direct coupling between the motor and the device to be driven

The only way to avoid these difficulties is to have a reduction gear train between the motor and provides the device to be driven so that the hydraulic motor can also be operated at relatively high speeds can, if a relatively low output speed is required · However, such reduction gears also work an undesirable dead gear, their use leads to an increase in the total inertia of the drive arrangement, and also the drive assembly responds more slowly to changing operating conditions · When the device to be driven is to be operated within a large speed range, which also includes low speeds, can also the speed of the hydraulic motor becomes too high at a high speed of the device to be driven5 this applies in particular for the Pail that the gear train works with a high gear ratio.

The object of the invention is now to provide a hydraulic motor which is designed so that the above-mentioned disadvantages do not occur even when the engine is operated at a low speed.

More specifically, the invention provides a dynamic hydraulic line Machine, e.g. a hydraulic motor, which has several right

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Includes cylinder, which is opposite to the rotatable output shaft Extending in the radial direction, as well as pistons which can slide in the cylinders and a non-rotatable piston with the output shaft connected, centrally located cams; the hydraulic motor according to the invention is characterized in that the cylinders are arranged in the form of several sets, and that the cam Has elevations, the number of which corresponds to the number of sets of cylinders! here every elevation of the cam has a symmetrical profile, and it includes a parabolic recess, so that, during operation, the combined instantaneous piston speeds for each set of cylinders and the combined instantaneous flow velocities of the hydraulic medium constant and equal to the maximum The piston speed or the maximum flow speed in a cylinder are «

Further, the invention provides a hydraulic motor comprising a centrally arranged cam which is connected to a rotatable drive shaft is _v-rotatably connected, and a plurality of pistons which are guided slidably in the associated cylinders, with the axes of the cylinders relative to the drive shaft in radial This hydraulic motor according to the invention is characterized in that the cylinders are arranged in the form of two sets and that the squat has two elevations which have a symmetrical profile and have parabolic sections, so that during operation of the engine the combined instantaneous values of the piston speeds in each set of cylinders and the combined instantaneous values of the flow speeds of the hydraulic medium are constant and equal to the maximum piston speed and the maximum flow speed in a cylinder, respectively ·

The hydraulic motor according to the invention can be connected directly to a device to be driven without it is necessary to provide a connecting device, e.g. a gearbox, between the motor and the device

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When the hydraulic motor the hydraulic pressure medium supplied with an exactly constant throughput rate the motor also works within each complete revolution with an exactly constant speed of rotation « Furthermore, the torque generated by the motor is within a wide range of angular velocities at a constant speed of the supply of the hydraulic pressure medium essentially constant

The cam is preferably profiled so that each elevation of the cam comprises parabolic sections, the number of which is equal to the number of cylinders of each set of cylinders * These parabolic sections are preferably connected to one another by arcs of a circle, which coincide with the axis of rotation of the cam are arranged concentrically and in the areas within which the cam has its largest or "its smallest radius" hatj in the middle of the flanks of the nook profile can be the parabolic sections by essentially straight sections be connected with each other «As a result, sights have lines through which the change in linear velocity each piston is shown in the preferred embodiment a trapezoidal shape "

In order to reduce the friction losses, each piston is preferably provided with a boll that is pressed against the cam. Each of these roles is preferably on one Axis arranged, which is mounted in a shoe or slider; between the slider and the associated piston is a Ball joint provided »Forces by which a piston is loaded transversely to its axis of movement are preferably of associated stationary guides added, in which rotatably mounted at the ends of the axis carrying the associated role are. With this construction, the motor responds quickly when its speed is to be changed.

The invention and advantageous details of the invention are shown below with reference to sohematic drawings on a Embodiment explained in more detail.

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Pig. 1 shows a "preferred embodiment of a hydraulic Motor according to the invention partly in a side view and partly in longitudinal section

Fig. 2 shows an end face of the engine according to Fig. 1 and. is a partial section along the line II-II in Pig. 1 drawn

Mg. 5 is an enlarged partial section along the length of the line III-III in Fig. 2.

Fig. 4 shows schematically the hydraulic connections between some of the cylinders of the hydraulic motor.

Fig. 5 illustrates in a polar diagram the change in the linear velocities of two pistons of the engine during operation.

Fig. 6 shows schematically the developed profile of a Increase in the motor cam, which causes the changes in piston speed shown in FIG. 5 to be brought about be o

1 to 4, the hydraulic motor comprises a total of Housing designated by 1 with two parallel disk-shaped end walls 2 and 3 separated by a distance, between which an annular component 4 is arranged.

The annular component 4 is provided with a plurality of radial cylindrical bores, each of which is a cylindrical Contains socket 5, in which an associated piston 6 is mounted such that it can be moved radially back and forth.

Each socket 5 is provided with annular channels 7, 8, 9 and, which in connection with tangential channels 11, 12, 15 and 14 are the pistons 6 move during their Working stroke one after the other past channels 7 "8, 9 and 10", Cedar piston 6 is provided between its ends with an annular groove 6a extending over its entire circumference, which establishes connections between certain channels of the socket 5 in a manner still to be explained «

ι ο

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ORIGINAL INSPECTED

The pistons 6 work with a centrally arranged Cam 15 together with a rotatable drive shaft 16 is wedged, which is coaxial with d®m ring part 4 in the housing 1 of the motor is mounted »'"

Each piston 6 cooperates with the cam 15 via a cam roller 17, which serves to apply a compressive force to the associated piston 6 or to be transmitted from this piston by means of a coupling comprising a slider 18 which is supported by the associated bushing and is connected to the piston 6 by a ball joint 19. The slide 18 carries a rotatable shaft 20 with which the associated cam roller 17 is keyed.

The axis 20 is provided at its ends with freely rotatable roller bearings 21 on matching guide surfaces 22, which are formed on the ring part 4 · The guides 22 take the lateral or the transverse direction acting components of the reaction forces between the pistons and the cam 15 during operation of the engine.

The cylinders of the engine are located on their radially outer side Ends closed with the aid of plug parts 23 which are supported by springs 24 which act on the pistons 6 in order to bias the pistons radially inward | be here the cam rollers 17 in contact with the cam 15 and the Sliders 18 held in contact with the associated piston 6

In the illustrated embodiment, the engine comprises eight similar, radially arranged cylinders, which the Motor shaft 16 symmetrically surrounded and two sets of four Form cylinders; the two sets of cylinders work with two similar elevations of the cam assigned to them together, the two cylinder sets are hydraulically connected in parallel.

According to FIG. 2, the cam 15 comprises two elevations, and according to the invention, each of the two forms sets of four Cylinders a drive unit with two pairs of cylinders,

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dl arranged symmetrically around the motor shaft 16 and extending radially outwardly with respect to the motor shaft When the motor is connected to a source for a hydraulic medium under constant pressure · With each revolution of the shaft 16, each piston 6 therefore performs a complete stroke movement twice ·

As each piston 6 comes into operation only during two quarters of a revolution of the shaft, it is ensured _t that the scalar sum of the flow rates, of the two pistons, which are each in a specific time to effect, constant and equal to the maximum value of the output of each Piston is "

This condition is met when the pistons of each working pair move at speeds equal to that of Pig. 5 illustrates the instantaneous velocities YI and Ύ2 of the two pistons of the one pair mentioned. The scalar sum V of the velocities V1 and V2 remains constant over time and is proportional to the resulting speed with which the two pistons move through their cubic capacity «

Fig «6 shows schematically the development of the profile of the Cam 15 and reveals the stroke that is caused by each of the two similar elevations of the cam, the each extend over an angular range of 180 ° «

According to Fig. 6, each elevation of the cam can be viewed as if it were divided into several sections, as indicated in Fig. 6 with dashed lines «Inside of each section within which the piston speeds V1 and V2 vary linearly, as shown in FIG is, the profile of the cam 15 has a parabolic shape. The shape of each of these parabolic sections can be defined by the

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OfHGtNAL INSPECTED

general quadratic equation. ''"""'"

j = oC x ² '

to be expressed; in this equation, χ and y denote the Cartesian coordinates along axes running at right angles to one another for one lying on the circumference of the cam Point, and ^ is one determined by the height of the cam profile Constant.

In order to improve the distribution of the hydraulic pressure medium to the cylinders, the individual parabolic, sections of each elevation of the cam where the radius is a maximum or a minimum, ie at the highest and lowest points, quickly merge into one another, and they are duroh connected substantially circular arc-shaped profile sections, corresponding to the piston speed to zero ₀ in the embodiment described here, each of these circular portions extending over an angular range of about 8 · of the cam profile. .

In addition, and in order to ensure the aforementioned constant resulting space sweeping speed V, are the individual parabolic sections in the areas of greatest steepness of the cam, i.e. in the middle between neighboring ones Flanks of each elevation, separated by straight sections that correspond to the maximum piston speed « These rectilinear sections, which are conveniently the polar projections of sections of an Archimedean Spiral, each extend over an angular range of about 8 ° of the Npckenprofil,

The parabolic ,, rectilinear and arcuate portions of the cam profile are in Fig. 6 shown in the form of a polar projection. With this representation, which applies to a single cam increase, i.e. for an angular range of the cam profile of 180 °, one recognizes the parabolic sections Pt, P2, P3 and P4, the extend over an angular range from 4 ° to 41 ° or 49 ° to or 94 ° to 131 ° or 139 ° to 176 °; at R1 and R2 the straight sections are shown, which the

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connect parabolic sections with one another and extend over an angular range of 41 ° to 49 ° or 131 ° to 139 °; at r1, r2, r3 and r4 are the circular connecting sections shown, which extend over an angle range from 0 ° to 4 ° or 86 ° to 90 °, or 90 ° to 94 ° or 176 ° extend up to 180 °; the neighboring sections r1 and r4 or r2 and r3 merge quickly with one another «

The second cam part cooperating with the second set of four pistons is similar to that shown in Figure 6 symmetrically, so that the two elevations extend over the entire angular range of 360 ° of the cam.

In the motor according to the invention, the supply of the hydraulic pressure medium to each cylinder is through the controlled piston operating in an adjacent cylinder; (0 each piston works like a slide valve to supply the hydraulic medium to the neighboring one To regulate cylinder and to determine that part of the work cycle during which this adjacent cylinder to Effect is brought about.

For this purpose, the ring-shaped component 4 of the motor housing is provided over its entire circumference with two channels 25 and 26, which are in direct connection with the aforementioned tangential channels 12 and 14 and each come into effect as a pressure medium supply channel or as a pressure medium discharge channel when the Wave 16 in the in]? Ig. 4 indicated direction of rotation is to be driven; if the shaft is to be rotated in the opposite direction, channels 25 and 26 are used in the opposite sense. this applies equally to both directions of rotation _{or the like}

In the annular housing part 4 or the end wall 3, a further channel 27 is formed, nder the tgcngentialen Channel 13 of each cylinder connects to the tangential channel 11 of the cylinder next to it in the clockwise direction, so that

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each piston alternates on its upstroke and its downstroke the adjacent cylinder with the pressure medium supply channel 25 or the outlet channel 26 connects.

If one designates the successive pistons and cylinders according to FIG. 4 in a clockwise direction with I, II, III, etc. VIII, the mode of operation of the motor in the event that the shaft 16 rotates counterclockwise can be described as follows.

At its bottom dead center position, which is the circular Corresponds to section r2 of the cam profile, connects the

T T

Piston I via the associated tangential channels 13 and 14 and the pilot channel 27 the tree above the neighboring one Piston II with the outlet channel 26 · The piston II overdeokt its own tangential channels 12 and 14, so that the Pressure medium supply duct 25 and the outlet duct 26 opposite the tangential duct 13 of the piston II and the pilot duct 27 shut off and therefore the connection to the piston III adjacent to the piston II is interrupted.

Since the piston III is offset by 90 ° with respect to the piston I and is in its top dead center position on the circular profile section r4 of the cam, this piston establishes a connection between its own tangential channels 12 ¹¹¹ and 13 ¹¹¹ .

Therefore, the hydraulic pressure medium is via the tangential channel 12 of the cylinder III, the pilot line

IV
27 and the tangential channel 11 fed to the upper or outer end of the cylinder IV above the associated piston IV, so that the piston IV in the cylinder IV is pressed radially near the inside.

The description given with regard to cylinders I to IV also applies mutatis mutandis to those that come into effect one after the other Cylinders V, VI, VII and VIII.

The piston VIII controls the first cylinder I, and in Pig. 4 it is located opposite the R1 section of the cam,

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so that it closes its tangential channels '12 and 14, the pilot line 27 shuts off and a connection of the cylinder I with the pressure medium supply channel 25 and the outlet channel 26 prevented

During the above-described part of the working cycle the two working pistons are formed by pistons IV and VIII, which generate the drive torque, the size of which depends on the pressure of the supplied hydraulic Pressure medium aligns. If the shaft of the motor continues to turn, two in a row come diametrically opposite each other opposite pistons for the Y / effect.

If the supply and outlet channels 25 and 26 are interchanged, for example with the aid of an electrically operated valve, the direction of rotation of the motor shaft 16 can be reversed.

Patent claims:

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Claims (9)

Claims Hydraulic machine with several extending in the radial direction with respect to a rotatable shaft Cylinders in which pistons are axially displaceable and with a centrally connected to the shaft in a rotationally fixed manner orderly crouching, because of the fact that the cylinders (5) are arranged in the form of a number of sets such that the cam (15) has a number of elevations, the number of which is equal to the number of sets of cylinders, and that every elevation of the squat arena is symmetrical and one parabolic Section Covers so that the combined instantaneous piston speeds at each set of cylinders and the combined instantaneous flow rates of the hydraulic fluid constant and equal to the maximum piston speed or the maximum flow rate in a cylinder are. 2. Hydraulic motor according to claim 1, characterized g e mark egg without knowing that the cylinder (5) in the form of two sets are arranged so that the cam (15) has two elevations with a symmetrical profile, the parabolic Sections (P1 to P4) includes, so that during the .Betriebs the combined instantaneous piston speeds at each set of cylinders and the combined instantaneous flow rates of the hydraulic _ 2 .- ■ 909 82 9/106 5 / 12 Ί8Ί0184 Pressure means constant! And equal to the maximum Kolbengesehwindigkeit or _e to the maximum flow rate is a cylinder · 3. · Hydraulic motor according to claim 2, characterized in that each set of cylinders has one Forms drive unit, and that the inlet ducts (12) and the outlet ducts (H) of the cylinders of each drive unit so with each other connected so that they are hydraulically connected in parallel 4 · Hydraulic motor according to claim 2 or 3 »characterized- that each cylinder (5) is provided with a Yorsteuerkanal (13) which through a pilot line (27) with the space above the KoHßens (6) in a tank adjacent cylinder is connected, that the piston in each cylinder acts as a slide valve, and that each piston optionally veraohlloses the Yorsteuerkanal (13) and connects the pilot line (27) with the inlet channel (12.) or the outlet channel (H) of the cylinder so as to control the supply of the hydraulic pressure medium to the adjacent cylinder. ' 5 · Hydraulic motor according to claim 4, characterized in that each piston (6) is provided with an annular groove (6a) between its ends, and that the pilot channel (13) of the relevant cylinder when the piston is positioned over the annular groove with the the relevant inlet channel äk (12) and, if the piston is in a different position, it is connected to the relevant outlet channel (14), 6, hydraulic motor according to one of claims 2 to 5, characterized in that the profile of the Cam includes parabolic sections (P1 to P4) within each elevation, the number of which is equal to the number of cylinders of every set of cylinders is 7. Hydraulic motor according to claim 6, characterized in that the parabolic sections (P1 to P4) of the cam are connected by sections (r1 to r #), 909829/1065 which are formed by circular arcs concentric with the axis of rotation of the cam and are arranged where the cam is has its largest or its smallest radius «, ^ 8 «Hydraulic motor according to claim β or 7, dadureh characterized in that the parabolic sections (P1 to P4) of the cam in the middle of the flanks of the Npokenprofils by essentially straight sections (R.1, R2) are connected# 9 · Hydraulic motor according to claim 8, characterized in that the profile of each straight cam section (H1, R2) comprises the polar projection of an Archimedean spiral and extends over an angular range which is twice as large _? like the angular range over which each of the circular profile sections (r1 to r4) extends, 10 »A hydraulic motor according to one of claims 2 to 9 _g dadureh gekennz eichnet that is supported by each piston (6) a Roll® (1?) And pressed against the cam (15) © 11 »Hydraulic motor according to claim 10, characterized in that each roller (17) on an axis (20) is arranged, which is mounted in a slider (18) which is connected to the associated piston by a ball joint (19) connected is" 12 · Hydraulic. Motor according to claim 11, characterized in that at the ends of each one Roller bearing axles (20) bearings (21) are provided, which in associated stationary guides (22) run, which are formed in an annular component (4) which is also connected to the the bores forming the cylinder are provided. 13 · Hydraulic motor according to claim 12, characterized in that g e- that the annular component (4) between-i see two parallel disk-shaped end walls (2, 3) arranged in which the shaft (16) of the motor is supported » 9 0982 9/1065 Empty soap