DE2338736A1 - HYDRAULIC MOTOR FOR THE ROTARY DRIVE OF AN EXCAVATOR GRAB - Google Patents

Description

PATENT ADVOCATE

ORESDNER BANK AO TELEPHONE: (0711) 3 * 3701/2 STUTTGART NO. 1OOOS3 *

TELESRAM: mentor 7 STUTTaARTI, PISCHEKSTR. 19 Post check STST. 35200-709

A 11 486

13 «July 1973

f - kt

Company Heinz T h u m m

7013 Oeffingen »Benzstrasse 9

Hydraulic motor for the rotary drive of an excavator gripper

The invention relates to a hydraulic motor for the rotary drive a gripper connected to the boom of an excavator or the like with one that can be connected to the boom Stator and one that can be connected to the gripper the stator rotatably mounted rotor, a plurality of either in the stator or in the rotor arranged radially, each accommodating a piston with a spherical ball, pressure cylinders open on the ball side and one on intended for the other part (rotor or stator),

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A 11 486

July 13 iy73

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serving as a rolling surface for the balls, in the radial direction wavy inner rim surface and one with this part rotatably connected divider to control dee Supply and return flow of hydraulic fluid to and from the pressure cylinders and at least the focal surface swisohen stator and rotor druokdioht durohsetsenden Drehdur guiding

Such a motor can be used wherever a hanging load is to be rotated around the vertical axis. A strong axial bearing is accordingly required. The Druokdiohten Srehdurchftorungen are for the to the
Hydraulic lines leading to the gripper are determined and are intended to prevent these lines from being entangled when the gripper is rotated around the vertical axis.

Ee a hydraulic motor of this type is known in which the rotary turntable within the distributor along the extends over the entire motor axis. A consequence of this is a relatively complicated structure of the entire system with a Multiple rotary feedthroughs to be sealed pressure-tight and a large number of individual parts to be assembled. Se is further perceived as a disadvantage that the

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A 11 486

July 13, 1973

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Manifold has a relatively large diameter and that a floating arrangement is not possible. Aue the reason show signs of wear and tear relatively quickly during operation, which in turn require relatively frequent maintenance. Because of the complicated structure the llotore, however, this is cumbersome and time-consuming.

The invention is based on the object of a hydraulic hot Or to create the type described above, which consists of only a few, easily manufactured items and especially is simple and therefore easy to maintain and which is also improved in terms of wear and tear is.

This object is achieved according to the invention in that the distributor is aohsmittig in a direction of rotation of the rotor concentric bore dee the pressure cylinder having .part is arranged and that the bores, millings or lines forming the rotary unions are outside the distributor get lost. With this construction must be taken into account be taken because the rotary unions are slightly larger than the known aohemittlgen arrangement Diameter are arranged. This difference falls; each <3; H

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A 11 486

13th July 1973

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hardly ine weight, because on the one hand the number of revolutions of this kind Hydraulic motor are relatively low and on the other hand the advantages achieved with the construction according to the invention in terms of The ease of manufacture and the greater ease of maintenance outweigh this small disadvantage in some cases.

In order to largely reduce the susceptibility to wear, especially in the case of transverse loads, it is proposed according to a further development of the invention that the distributor has a radial and an axial play with respect to the part to which it is connected in a rotationally fixed manner. With such a so-called floating arrangement, the distributor can easily evade transverse forces and axial forces, whereby the bearing forces transmitted to the bore wall are greatly reduced compared to a rigid mounting. A further improvement in which he β respect is achieved in that at least one of the two supply lines for the hydraulic fluid of the distributor as a between the outer wall of the distributor and the bore inner wall of the - formed annular channel, the printing cylinders having part formed Ia ^ * It is thereby achieved that the contact surface between the outer wall of the distributor and the inner wall of the bore is relatively small and the plain bearing formed in the area of this contact surface is well lubricated by the hydraulic fluid.

509808/0063 BAD original

In addition, with these precautions, the thermometer of the Distributor can be reduced to a minimum.

The manufacture of the individual parts of the engine and their assembly is particularly easy if the distributor is a is a one-piece rotating part and if, in addition, the part having the pressure cylinder is a one-piece rotating part and the one-piece part having the wave-shaped inner wall of two connected to one another at a flange connection Consists of individual parts that partially include the first-mentioned part · the hydraulic motor consists of this Case made up of four simple basic bodies, each of which can easily be produced on a lathe, for example and which can be easily disassembled and reassembled, e.g. for maintenance purposes, even in rough construction site operations.

According to an advantageous development of the invention is located on the gripper side between the Botor and the stator at least one washer, which when the gripper is pressed on acts on a base as an axial thrust bearing and otherwise as a plain bearing. This washer is especially used Wear reduction.

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The hadial forces between the stator and the rotor are advantageous added by a plain bearing, which is taken from the bores and millings that form the rotary unions can be penetrated · In order to avoid rotary feedthroughs for the hydraulic medium driving the motor, it is proposed that that the part having the pressure cylinder as a stator and the part having the wave-shaped inner wall is designed as a rotor.

In the drawing is an exemplary embodiment of the invention Shown in a schematic way · It shows

fig. t a sign of one associated with a cantilever Gripper and a schematic representation of a control device for the hydraulic motor;

fig. 2 shows a longitudinal section through the hydraulic motor, wherein the stator is cut in two different axial planes;

Flg. 3 is a partial section perpendicular to the longitudinal axis of the Hydraulic motor.

The gripper 10 is gimbaled to a boom 11 of an excavator, otherwise not shown in the drawing

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hung up. Between the universal joint 12 and the gripper 10 supporting rod 13 is a hydraulic motor H, with the help of which the gripper can be rotated about a vertical axis let. This is part of the hydraulic hot connected to the boom 11 or β, ale stator 30 and the part connected to gripper 10 is referred to as rotor 60. You for the drive the hydraulic motor required supply and return lines 15, 16 for the hydraulic fluid are on the stator side Connections 31, 32 connected to the Uetor. The drive of the engine is carried out in that in one of the two hydraulic lines 15 by means of a pump 17 and a. ! Pressure relief valves 18 a certain overpressure is generated, while in the other line 16 about atmospheric pressure prevails. The hydraulic fluid is taken from or into a container 19 under atmospheric pressure demanded this back. By means of a directional control valve that can be held back 20 the overpressure can be generated either in one or in the other line 15 »16 and thus the direction of rotation of the engine can be determined.

On the side of the stator are connected to the connections 33 and two further hydraulic lines 21, 22, which via a rotary feedthrough with the rotor side to the connection

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Bohlüseen 61, 62 connected lines 21 ', 22' connected are ο These lines lead eu one that actuates the gripper arms Device that is controlled by means of a control device. The lines 21 and 21 * BSW. 22 and 22 * connecting rotary shafts within the engine should be a Prevent the cables from sticking together when the gripper is turned.

As shown in FIGS. 2 and 3, there is the hydraulic motor from a stator 30, one on a ring shoulder 35 of the stator with the interposition of a roller bearing 36 rotatably mounted rotor 60 and a rotary distributor arranged in a central bore 37 of the stator The stator can be in the area of the Durohbruohes 38 with the excavator boom 11 and the rotor are connected to the gripper bar 13 at the part 64 flanged to its bottom 63.

In the stator body there is a number of in the circumferential direction Equally spaced radial cylinder bores 39 'in each of which a piston 40 and one against the end face of the piston, durr-rh a cylinder opening 41 extends more or less far through it Ball 42 are arranged »On their back 43 are the

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Piston loaded with hydraulic fluid »through the bore 44 enters the cylinder. They are balls 42 reaching through the cylinder openings 41 against an undulating curve in the circumferential direction with radial deflections descriptive inner surface 65 of the rotor 60. The wavy curve is also called Stroke curve 65 * denotes, since it determines the stroke of the pistons 40 at any point in time.

If a ball 42 is now over the associated piston 40 with With the help of the hydraulic fluid pressed against the inner wall 65 of the rotor with a certain radial force, so exercise depending on the size and direction of the slope of the lifting curve 65 »at the relevant contact point a more or less large torque in one or the other direction of rotation on the rotor. TIm set the rotor to turn can, the balls must transmit a rectified torque to the rotor. Ss are therefore only allowed to be Pistons are pressurized, the balls of which against a flank pointing outwards against the direction of rotation When the rotor rotates, these pistons move with their balls under the action of the high Pressure of the hydraulic fluid radially on the lifting curve

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outwards until the outer dead center is reached. At the same time, the associated cylinders are grounded with hydraulic fluid filled. All those cylinders, the balls of which are against a flank of the lifting curve which flanks inwards against the direction of rotation are present, however, must be connected to a low pressure return line so that the relevant Pistons can be moved radially inwards when moving past the lift curve without great effort and the Hydraulic fluid out of the cylinder into the return line can be promoted. When the stroke movement reaches a dead center, the existing connection of the The cylinder concerned is interrupted with one of the hydraulic lines and a connection is established as the movement continues with the other hydraulic line. This takes place, for example, when the outer dead center is reached a reversal of the cylinder connection from the under high Supply line under pressure to the return line under low pressure.,

The in-phase control of the with respect to the lift curve 65 ' Connection of the individual pressure cylinder with the supply and return line takes over the manifold 90, which is connected to the Rotor 60 carrying the lifting curve by means of a driving pin 66

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non-rotatably connected let. The distributor knows for this purpose a number of axial grooves that one in the circumferential direction have a constant distance from each other and together with the inner wall of the bore 37 each have a slot channel 91, form. The slot channels 91 stand via the ring channel 93 BdLt of the aneole opening 31 for the hydraulic line 15, and the two two Schiita channels 91 arranged in each case Slot channels 32 are above the annular channel 94 and the bore 95 BdLt of the connection port 32 for the other hydraulic line 16 in connection

When the distributor, which is old coupled to the rotor 60, is rotated, the edge openings of the hats forming the slot channels 91 and 92 are successively brought into congruence with the bores 44 leading to the cylinders 39, which successively establishes a corresponding connection between the cylinders and one or the other hydraulic system. Line 15, 16 is established. The arrangement of the grooves forming the slot channels 91, 92 on the distributor, the wave crests and wave troughs of the curve 65 on the rotor 60 and the pressure cylinder with their bores 44 and openings 41 in the stator 30 is so correctly angularly coordinated that a continuous rotation of the rotor in the oven-drilled hole ^; se

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can be done. From the geometrisohen shown in the drawing Allocation of these parts to one another is easy to see that a rotation of the rotor relative to the stator takes place in one or the other direction, depending on whether the fluid is in one or the other hydraulic line 15, 16 connected to the connections 31 and 32 is under pressure

There are two further connection openings 33, 34 on the stator 30 for those in Pig. 1 hydraulic lines 21, 22 are provided, each of which has a bore 45, 46 and a rotary leadthrough 47, 48 with the associated connection openings 61, 62 provided on the rotor 60 for the hydraulic lines 21 ', 22 * are connected. The rotating unions are located in the area of a radial plain bearing 51 «the one with the bores 491 50 on the one hand and the bores 68, 69 on the other hand in Connecting annular channels 70, 71 of the rotary feedthroughs are each provided on both sides by means of sealing rings 72, 73, 74 sealed against each other and to the outside.

The hydraulic motor described consists of a few individual parts that can be assembled very easily. The base body forming the stator 30 is a one-piece,

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Rotary valve provided with corresponding holes. Also The distributor 90 is designed in one piece and can be very easily inserted into the hollow bore 37 of the stator body let. The main body of the stator 30 partially overlapping Eotore 60 consists of two single points 75 »76, which are connected to one another at a flange connection 77. During assembly, the one becomes essentially hollow-cylindrical Part 76 of the rotor from one side and the other cup-shaped part 75 from the other side over the stator body 30 “after the roller bearing 36 and the two ring disks 78 have been inserted beforehand. The two Ring disks 78 serve on the one hand when the load is suspended Plain bearings and on the other hand when pressing the gripper on a pad as a! pressure bearing. The distributor 90 let backlash-free by means of the driving pin in the TJmf arrangement coupled to the rotor 60, but the pin connection allows both radial and axial play opposite the rotor. Compared to a rigid connection, this has a so-called floating arrangement of the distributor the advantage of less wear in the area Contact surfaces «between the distributor and the stator ·

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Of course, in the case of an external construction, the action on the stator and the rotor can also be reversed in the slime of a kinematic text. Reversal was possible with both floating and rigid arrangements of the distributor.

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Claims (8)

-ns. Expectations Hydraulic motor for the rotary drive of a gripper or the like connected to the boom of an excavator a stator which can be connected to the boom and a stator which can be connected to the gripper and is rotatably mounted on the stator Rotor, an Ilehrzahl of either in the stator or in the rotor arranged radially, each with a piston with a On the etiraside mounted ball receiving, ball side open pressure cylinders and one provided on the other part (rotor or stator), the balls as Rolling surface serving, in the radial section wave-shaped inner wall surface and one with this part non-rotatably connected distributor for controlling the inflow and return flow of hydraulic fluid to and from the Pressure cylinders as well as at least two rotary rotary guides penetrating the separating surface between stator and rotor in a pressure-tight manner, characterized in that the distributor (90) is aohsmlttig in one to the axis of rotation of the rotor (60) concentric bore (37) of the part (30) having the pressure cylinders (39) is arranged and that the bores (4-5, 49 t 68; 46, 50, 69) cutouts (70, 71) or lines 509808/0063 - 2 - 1 - run outside the distributor (90) « 2. Hydraulic motor according to claim 1, characterized. marked that the manifold (90) is connected to the part (60) with which it rotates has a radial and an axial play 3. Hydraulic motor according to claim. 1 or 2, characterized in that at least one of the two supply lines for hydraulic fluid des Manifold (90) as one between the outer wall of the manifold and the inner wall of the bore (37) of the pressure cylinder (39) having part (30) formed annular channel (93) is formed. 4. Hydraulic motor according to one of claims 1-3, d a characterized in that the distributor (90) is a single turned part. 5. Hydraulic motor according to one of claims 1 - 4, characterized in that the the part (30) having the pressure cylinder (39) is a one-piece rotating part and the inner wall is corrugated 609808/0063 3 (65) having part of two on a flange connection (77) interconnected, one-piece individual parts (75 »76), which partially include the former! Dell (30). 6. Hydraulic motor according to one of claims 1-5 »g β indicates by at least one arranged on the gripper side between the rotor (60) and stator (30), Blngeoheib serving as an axial thrust bearing and as a plain bearing «(78). 7 · Hydraulic motor according to one of claims 1 - 6, characterized by one which absorbs the radial forces between the stator (30) and rotor (60) Plain bearing (51). 8. Hydraulic motor according to claim 7, characterized in that that the bores and millings forming the rotating unions that the sliding bearing (51) enforce forming contact surfaces. 9 «hydraulic motor according to one of claims 1 -8, d a durohgekennzeioh.net, that the 509808/0063 4 - The part (30) having the pressure cylinder (39) as a stator and the part having the undulating inner wall (65) (60) is designed as a rotor. 509808/0063