DE1453701A1 - Inclined drum axial piston motor - Google Patents

Description

Applicant: The Weatherhead Company, Cleveland, Ohio, USA

Inclined drum axial piston motor

The invention relates to an inclined drum axial piston motor, whose inclined cylinder drum is connected to a drive shaft via loose splines, one of which is part of the drive shaft stored in a bearing in the control mirror disk while the other end of the drive shaft drives an output shaft via a bevel gear.

With engines of this type (USA patent specification 3 053 197) there is a problem that considerable stresses due to moments exerted on the housing during operation can occur, which are the result of high pressure differences in different areas of the engine. Through the invention if these stresses leading to deformations are to be reduced as far as possible, in order to avoid leakage losses and to maintain an even and constant contact pressure between the control plate and the cylinder drum.

In another engine of different types, it is already known (US Pat. No. 2,642,810) that in one Inclination of the axis of the drive shaft with respect to the axis of the cylinder drum the component exerted on the piston the cylinder drum pivoted. Therefore there will be a spline provided between the cylinder drum and the drive shaft in the area of the center of the drive pulley for the pump piston.

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A deflection of the drive shaft can be absorbed by this measure. In contrast, the invention lies in the knowledge based on the fact that the deformations of the housing must be absorbed so that the control plate at any time is in good contact with the face of the cylinder drum. In pumps of the type mentioned (USA patent specification 3,053,197) on the other hand, in order to avoid difficulties of this kind, to establish a particularly stable connection between the cylinder drum and the control mirror disk in order to achieve relative Avoid tilting movements. With such an arrangement, however, additional moments are transmitted to the housing and tolerance difficulties increased. Further be Deformations of the housing are not adequately compensated, which leads to the leakage losses mentioned between the control mirror disk and can lead to the housing «

An inclined drum axial piston motor of the type mentioned at the outset is characterized according to the invention in that the splines near the end face of the cylinder drum resting against the control plate, the bearing is provided in the control plate disc has a bearing housing with a radially projecting annular contact surface, while the remainder The outer surface of the bearing housing is at such a distance from the inner surfaces of the control plate disk surrounding it, that the bearing housing is pivotable when the cylinder drum moves around the spline, so that the control plate continues to bear against the end face of the cylinder drum, and that the openings in the control plate disc each with a floating connecting pipe with the motor housing in connection. This allows pressure differences conditional forces with regard to both the cylinder drum and the control plate disc. can be taken while the stresses or deformations exerted on the pump housing are reduced. It stays therefore ensures that the control plate disc remains level even at very high pressure, which the control plate is exposed when the engine is running. Because the contact of the steering mirror is most critical when with the lowest Volume and the highest pressure is used, is

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moderately in each cylinder bore a compression spring is provided, which presses the cylinder block against the control plate. The hydraulic forces are part of these chambers of the engine wise balanced in order to reduce the forces between the cylinder drum and the control plate disc.

. The invention is to be explained in more detail with reference to the drawing. Ee show χ

Fig. I a longitudinal section through a hydrostatic Motor according to the invention;

Fig. 2 is an end view of the bearing against the control plate End face of the cylinder drum;

Figure 3 is an end view of the control mirror;

4 is an enlarged end view of the opposite end face of the control plate; *

FIG. 5 is an enlarged partial section along the line 5-5 in FIG. 4;

Fig. 6 is a cross section to explain the structure of one of the transfer sleeves, which the passage openings of the Control mirror with the pressure medium line and the return flow openings connect the housing;

Fig. 7 is a cross section illustrating the arrangement of the connecting rods in the reaction member; and

8 is an end view of the housing, from which the position of the passage openings serving for the supply and for the return flow, respectively can be seen in the housing.

The illustrated preferred embodiment of a hydrostatic motor according to the invention has a main housing 10 and an end housing 11, which are connected to one another by bolts 12 and sealed by an O-ring 13 are. The output shaft 14 is supported in the end housing 11 on roller bearings 16 and 17. Having conical rolling Bearing 16 is particularly suitable for accommodating axial and also radial ones Suitable loads, while the bearing 17 can mainly absorb radial loads. The two camps serve

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however, overall, the reaction member 14 in the end housing 11 in the axial direction for rotation about a first axis 18 to fix. The end of the output shaft 14 protrudes beyond the end of the inner housing and is provided with a keyway 19 or the like provided to connect the output shaft 14 to the load when the device is used as a motor, or ' with a power source in the case of use as a pump. A seal 21 is in the end housing 11 by means of a clamping ring 22 arranged to prevent leakage from the interior of the housing along the output shaft.

A control mirror disk 23 is provided at the end of the housing 10 opposite the output shaft 14 and has a radial control plate 24, which on one end of the cylinder block 26 is present. The cylinder block 26 has a series of symmetrically arranged cylinder bores 27, which extend parallel to each other. An odd number of cylinder bores 27 is preferably provided, as in FIG. 2 is shown. In each cylinder bore 27 there is a piston 28 which is connected to the output shaft 14 via a piston rod 29 communicates.

In order to enable synchronous rotation of the output shaft 14 with the cylinder block 26, there is a first spur gear ■ 31 fastened on the output shaft 14 with a bolt 32. A drive shaft 33 is connected to a second spur gear 34 which is in engagement with the gear 31. The drive shaft 33 is rotatably supported at its ends so that it can rotate about a second axis 36 inclined to the first axis 18 and this axis at the center of a Ball bearing 38 intersects which has ball sockets 39 and 41 in gear 31 and drive shaft 33, respectively. This ball bearing ensures both an axial and a radial localization of the gear wheel 34 of the drive shaft 33 and enables free pivoting between the drive shaft and the output shaft. The other end of the drive shaft 33 extends through an axial bore 37 in the cylinder block and is mounted radially in a roller bearing 42 which is carried by a bearing housing 43.

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A thrust bearing 44 is arranged between the end of the bearing housing 43 and a thrust bearing washer 46, the in turn rests on a shoulder 47 on the drive shaft 33. This thrust bearing is used for the axial alignment of the Drive shaft to the bearing housing 43 and the ball bearing 38. At the point 48 there is a play between the disc 46 and the cylinder block 26 is provided to inevitably prevent any contact between these bearings and the cylinder block to prevent.

The bearing housing 43 has a projection 49 on the outer circumference, which protrudes on the inner wall of an axial blind bore 51 in the control mirror disk 23 is applied. This results in a radial support of the bearing housing 43. Since, however, the projection 49 has a relatively short axial length or can be spherical, the bearing housing can extend to the drive shaft Align 33, even if the bore 51 is not exactly aligned with the axis 36. A bolt 52 extends in holes in the control mirror disk 23 and the Bearing housings 43 are designed to prevent relative rotation. However, there is sufficient play, so that the bolt 52 does not prevent the bearing housing from aligning itself freely with the axis 36.

An adjusting bolt 53 extends through a bore 54 in the control plate disk 23 and a bore 56 in the Housing 10 and its outer end rests against an adjusting screw 57 which is screwed into the housing 10. A seal 58 at the junction of the bores 54 and 56 prevents leakage losses along the adjustment bolt 53. The The inner end of the adjusting bolt 53 rests on the bearing housing 43. An external setting of the adjusting screw 57 enables an axial adjustment of the drive shaft 33 to provide suitable clearances for the ball bearing 38 and between the gears 31 and 34 to enable. It is therefore not necessary to provide these parts with very tight manufacturing tolerances, because a simple device for compensating for differences due to manufacturing tolerances can be used, and thus further

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Occurring signs of wear can be compensated.

The drive shaft 33 extends through the bore 37 in the cylinder block 26 with play to a point adjacent to the StsuerspiegeIscheibe 23 Enable drive connection between the drive shaft and the cylinder block. The splines 59 are formed with such a loose fit that play and misalignment between the axis of rotation 36 of the drive shaft 33 and the axis of rotation of the cylinder block 26 is possible. Because of the loose fit of the splines 59, no forces can be transmitted from the gear member 33 to the cylinder block 26 which could lift or tilt the cylinder block relative to the end face 24. The cylinder block 26 can therefore suitably rest against the control plate 24, even if the control plate 24 does not run exactly perpendicular to the axis 36. This freedom of bearing adjustment keeps leakage losses to a minimum and ensures reliable operation. The splines ¹ 59 ensure the radial localization of the cylinder block relative to the axis 36 and the control plate disk 23. The small radial freedom due to the loose splines does not adversely affect the operation of the engine, since the radial arrangement of the control surface is not overly critical. However, if the teeth of the spline are made spherical, radial play can be eliminated while maintaining limited universal alignment characteristics.

Each of the cylinder bores 27 has an associated cylinder opening 61 on the control surface of the cylinder block 26 Mistake. This connection results from stepped bores 62 and 63 which are connected by a radial shoulder 64 are. A return spring 66 extends between the shoulder 64 and a radial surface 67 attached to the piston 28 is designed to press the piston resiliently towards the output shaft 14.

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As can be seen from FIGS. 3 and 4, the control surface of the control plate disk 23 has two curved passage openings 68 and 69 which in turn communicate with inlet and outlet ports 71 and 72, respectively. A Transition section 73 shown in FIG. 5 connects the associated inlet and outlet openings.

The control plate is located radially within the openings 68 and 69 24 is provided with an annular groove 74 which is provided with a number of symmetrically arranged drainage lines 76 communicates. In a corresponding manner, an outer annular groove 77 is formed around the passages 68 and 69, which communicates with the main space of the engine via a number of radial grooves 78. The grooves 74 and 77 cooperate to limit the sealing area of the adjacent control surfaces of the control mirror disk 23 and the cylinder block 26. The control plate 24 and the surface of the cylinder block 26 engaging it must be precisely formed must also be precisely designed so that a suitable seal is achieved. However, the opposite The end face 79 of the control plate disk 23 and the end face 81 on the housing 10 are not manufactured with tight manufacturing tolerances be, since they are only used for the axial localization of the control plate disc in the main housing 10, and the Cylinder block 26 can freely rest against the control plate 24, even if this surface is not exactly perpendicular to it the axis 36 runs. When the main housing 10 is deformed by stress and allows the control mirror disc 23 moves relative to the axis 36, there is no problem because the cylinder block 26 is can move freely into the appropriate position relative to the control plate disk 23.

An essentially hydrostatic equilibrium To enable the control mirror disc, transfer tubes in each of the openings 71 and 72 are used. The transfer tube 82 in the inlet port 71 is shown in FIG. A similar tube is in the outlet port 72

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arranged. The transfer tube 82 extends from the inlet port 71 into a corresponding bore 83, which is formed in the main housing 10 and connected to the engine inlet 84 is. The transfer tube 82 is provided on its outer periphery with a first seal 86 which against the inlet opening 71 seals, as well as with a second seal 87 ,. which seals with the bore 83, so that the transfer tube both relative to the control mirror 23 and is freely displaceable to the housing 10.

Preferably, the size of the inlet opening 71 is approximately 90% of the size of the associated opening 68; it is arranged so that they are practically coaxial with the center of the area or centroid of the cross section of the valve opening 68 runs. Therefore, a hydrostatic reaction force which would push the valve plate towards the end wall 81 becomes essentially balanced by an opposing hydrostatic reaction force acting in the opposite Direction along the same line of attack acts. Therefore, the valve plate is not subjected to any significant force, which warp or bend the plate so that the valve surface 24 stays. The small unbalanced force is used to hold the valve plate in a suitable position in the housing 10.

Furthermore, the cylinder block is subjected to an unbalanced force which brings it into sealing contact preloaded with the valve plate. The cylinder openings 61 have a cross section which is smaller than the cross section of the Cylinder bores is. This cross-sectional difference is greater than the area of the cylinder block between the openings 61, which is exposed to the high pressure in the openings of the control mirror. These areas are chosen so that a resultant force results, which biases the cylinder block against the valve plate, so that the contact force between the valve surface 24 and the associated end of the cylinder block 26 in direct dependence on the sealed Pressure increased. This ensures that at all times

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a suitable seal is in place. The springs 66 create a reaction force on the cylinder which is the hydrostatic Increased sealing force and also ensures that the cylinder block continues to bear against the valve plate, so that a suitable seal is in place when the motor starts up.

The torque required to rotate the cylinder block 26 with the reaction member 14 is relatively small Comparison to the output torque of the motor. However, any torque transmitted through the gears 31 and 34 is pushing the gear member in a direction in which alignment with the first axis 18 is effected. This drive reaction force is received by the bearing cage 43 and the valve 23, and is not transmitted to the cylinder block 26. The order the loose splines 58 substantially adjacent to the valve plate 23 ensures that the centering or radial localizing forces exerted on the cylinder block do not generate a significant tilting force cause.

As can be seen from FIGS. 1 and 7, each piston rod 29 is provided with a spherical end part 91, which is seated in a ball socket 92 in the piston 28. Each piston 28 has a bore 93 which extends from the ball socket 92 extends to a conical section 94, which in turn extends to a larger second bore 96. The engagement of the spherical end portion 91 on the spherical socket 92 results in a self-centering connection, which transmits the driving forces from the piston to the reaction member while having sufficient play is provided to allow the necessary pivoting.

When the engine is operating under load driven conditions or otherwise Rotates conditions under which the fluid pressure forces and the spring forces of the springs 66 do not move the pistons 28 to the reaction member at a sufficient speed to the Maintain contact with the connecting rods 29, moves the spherical end portion 91 only to the right, as can be seen from Fig. 1, so that it is out of engagement with the

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Pan '. However, the elements are so proportioned that the spherical end portion 91 remains in the hollow parts of the piston 28 and in its suitable seated position through the bores 93 and 96 and the conical section 94 is returned. Because it doesn't require an absolute touch Lighter springs 66 can be used to maintain between the pistons and the associated connecting rods than would otherwise be necessary.

The end of each piston rod 29 adjacent to the reaction member is best made in terms of its design Fig. 7 can be seen. The reaction member 14 has a ball socket 97 for each connecting rod 29. The adjacent End of the connecting rod is with a head 100 with a spherical end face 98 provided, which normally rests against the wall of the pan 97, to a pivotable connection to enable the transmission of the driving forces to the reaction member 14.

In order to ensure that the heads 100 of the piston rods remain in the associated sockets 97, a retaining plate is provided 99 arranged on the reaction member 14 with the aid of a clamping ring 101. An opening 102, the diameter of which is smaller than the maximum diameter of the button 100 is formed in the holding plate adjacent to each of the pans 97. Therefore, each head 100 is inevitably in the associated socket 97 after this mechanism has been assembled held. The center of curvature of the socket 97 is located within the opening 102, so that a pivoting of the connecting rod 29 does not have too much play between the opening 102 and the connecting rod 29 required. Preferably is the connecting rod 29 with a short section 103 with provided a reduced diameter in the vicinity of the opening 102. However, the opening 102 must have a diameter which is slightly larger than the major diameter of the connecting rod to enable assembly of the assembly.

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In the bearing housing 43 and the cylinder block 26 drain channels 104 and 106 are formed, which together with the Drain lines 76 ensure that the pressure is not in the central zone is built up between the cylinder block and the valve plate. The openings 106 are about the clearance between the gear member 3 3 and the cylinder block bore 3 7 connected to the main space. Openings 107 and 108 are in the main housing 10 and the end housing 11 are provided to allow drainage from the main room.

When the cylinder block 26 is arranged so that he can move freely with the valve plate and is not exposed to any forces that affect it relative to the Valve plate could tilt, an effective valve action is maintained, even if the valve surface 23 is relative to the axis 36 is not precisely arranged. Furthermore, the use of hydraulic balance avoids a considerable amount of work Part of the forces on the valve plate are a bending thereof, and furthermore, together with the floating bearing, a suitable valve action under all operating conditions. The simplified training of the connecting rods with a simple and inexpensive retainer on the reaction member without the need to necessarily retain the piston end enables reduced manufacturing costs and simplifies the arrangement without sacrificing the efficiency, the versatility or affect the service life.

Claims

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Claims (2)

U53701 May 13, 1969 E / Sm JfiP 14 53 701.0-15 Λ I My files: W-1279 New claims 1. Inclined drum axial piston motor, the inclined cylinder drum via a loose spline with a drive shaft is connected, of which a drive shaft part is mounted in a bearing in the control mirror disk, while the other end of the drive shaft drives an output shaft via a bevel drive, characterized in that that the splines (59) close to the end face of the control plate (24) resting on the Cylinder drum (26) is provided that the bearing in dor Control plate disc (23) has a bearing housing (43) with a radially projecting annular contact surface (49), while the remaining outer surface of the bearing housing (43) is at such a distance from the inner surfaces surrounding it Steupi regulating disc has that the bearing housing is pivotable is when the cylinder drum (26) revolves around the spline (59) moved so that the control plate (24) continues to bear against the end face of the cylinder drum, and that the openings (71,72) in the control plate disc each are in communication with the motor housing by means of a floating connecting pipe (82). 2. Motor according to claim 1, characterized .ζ ei c h η ο t that the inlet opening (71) of the control mirror disk has a cross-sectional area that is about 90% the associated control opening (68) in the control plate, and that the inlet opening (71) - essentially coaxial is arranged with the central region of the control opening (68). 3; Motor according to claim 1, characterized gekennz ei ch η c t that the cylinder openings (61) have at the cylinder drum a cross-sectional area which is smaller by a difference than the cross-sectional area of the cylinder bores which is greater than the «AD 009831/0063 Inlet pressure exposed area of the cylinder block between the cylinder openings (61), and that the cylinder drums is pressed by springs (66) against the control plate (24). 009831/0063 4Lf Blank page