Hydrostatic rotary machine with brake disc received on a bolt

Abstract

The invention relates to a hydrostatic rotary machine having an inner element and an outer element, which are coaxial with respect to an axis of rotation and are rotatable relative to one another, wherein one of the elements is a rotor and the other element is a stator, wherein a piston movable in a cylinder can cooperate with a cam surface such that a rotary movement of the rotor is accompanied by a reciprocating movement of the piston, wherein a brake is provided, which is designed to prevent a rotary movement of the rotor relative to the stator, wherein the brake has a plurality of first brake discs and second brake discs, which are arranged alternately along the axis of rotation, wherein the first brake discs are connected in a torsionally rigid manner with respect to the axis of rotation to the outer element. According to the invention, at least two bolts are provided, which each extend parallel to the axis of rotation, wherein the bolts are fixedly connected at a first end directed in the direction of the axis of rotation to the inner element, wherein each of the bolts extends through all of the second brake discs such that the second brake discs are connected in a torsionally rigid manner with respect to the axis of rotation to the inner element.

Description

Technical Field

[0001] The present invention relates to a hydrostatic rotating machine according to the preamble of claim 1. Background Technology

[0002] A hydrostatic rotating machine in the form of a radial piston motor is known from EP 3 233 553 B1. In the radial piston motor, an outer element forms the stator, while an inner element forms the rotor. The inner element is coaxial with respect to the outer element and is rotatably supported on the outer element about the axis of rotation. Furthermore, a corrugated cam working surface is provided on the inner circumferential surface of the outer element. Pistons are movably received in the cylinder of the inner element. These pistons cooperate with the cam working surface via rotatable rollers such that the rotational motion of the rotor causes the reciprocating motion of the pistons, and vice versa.

[0003] Furthermore, a brake system configured as a multi-disc brake is provided. The first and second brake discs of the brake system are arranged around the fluid distributor to save structural space. The second brake disc is torsionally connected to an annular protrusion, which is integrally formed from the substrate of the internal components. Therefore, the manufacture of this substrate is very expensive. The aforementioned substrate is manufactured by machining, which requires a large piece of raw material due to the aforementioned annular protrusion, and the machining of this raw material takes a considerable amount of time. Summary of the Invention

[0004] The advantage of this invention is that the manufacture of hydrostatic rotating machinery can be carried out at a lower cost without causing any disadvantages in the performance of the brakes.

[0005] Claim 1 includes at least two bolts extending parallel to the axis of rotation, each bolt being fixedly connected to an internal element at a single end pointing in a direction along the axis of rotation. Each bolt passes through all second brake discs, such that the second brake discs are torsionally connected to the internal element about the axis of rotation. A multi-disc brake, for example, is known from US 3,722,637 A, in which a set of brake discs is received on multiple bolts. However, in such a multi-disc brake, the bolts are always supported at two opposing ends because they must transmit a large force. This is not feasible for hydrostatic rotating machinery according to EP 3,233,553 B1. Therefore, the inventors have overcome the prejudice that bolts supported only on both sides can transmit the forces present in a multi-disc brake. The inventors have also recognized that, precisely for hydrostatic rotating machinery, bolts can be made so robustly and thus fixed to the remainder of the internal element that the bolts can support the braking forces present during operation with the necessary rigidity.

[0006] The external components preferably form the stator, while the internal components form the rotor. The reverse arrangement is also conceivable. The cam working surface is preferably arranged on the stator, while the cylinder is arranged on the rotor. The reverse arrangement is also conceivable. Most preferably, the cam working surface is arranged internally on the external components.

[0007] Advantageous extensions and improvements of the invention are described in the dependent claims.

[0008] It can be specified that the number of bolts equals the number of pistons. This allows for the use of a larger number of bolts, enabling each individual bolt to withstand a smaller load. Furthermore, all bolts can be very rigidly secured to the remainder of the internal components alongside the cylinder, without requiring additional structural space for the internal components.

[0009] It can be specified that the pistons and bolts are arranged evenly around the axis of rotation, with the bolts arranged between the pistons in a circumferential direction about the axis of rotation. In this region, the internal components are constructed very robustly, allowing the bolts to be held there very rigidly.

[0010] It can be specified that each bolt is assigned a radially outwardly pointing protrusion on all first brake discs, wherein the protrusion is embedded in a separately assigned groove on the external element. When the brake is closed, the braking force is transmitted from the protrusion through the brake disc to the bolt in a particularly short path. Therefore, the elastic deformation on the brake is reduced to a minimum under the action of the braking force. It should be noted that multi-disc brakes can cause noise, especially squeaking noise, which should be avoided as much as possible. The aforementioned elastic deformation may be the cause of such undesirable noise, and the applicant's tests have shown that the hydrostatic rotating machinery according to the invention does not squeake.

[0011] It can be specified that the bolts are each manufactured as individual components, which are screwed into the internal element at their respective first ends. The threaded connection can be secured, for example, with adhesive to prevent loosening. In this way, the desired rigid connection between the bolts and the remainder of the internal element can be established in a particularly cost-effective and simple manner.

[0012] It can be specified that the bolt has a form-locking device at a second end opposite to the first end along the direction of rotation axis. This form-locking device is configured for form-locking engagement with a screw tool. This simplifies bolt installation. The form-locking device can be, for example, an external hexagon, an internal hexagon, an internal six-point profile, or a slot.

[0013] It can be specified that the bolts each have a cylindrical section on the outside of the internal component, the cylindrical section's axis of rotation being arranged parallel to the axis of rotation, with the second brake disc disposed within the region of the cylindrical section. Preferably, all second brake discs are disposed within the region of the cylindrical section. The form-locking fit between the cylindrical section and the second brake disc thus induces small surface pressure on the surface of the cylindrical section. Furthermore, easy installation of the second brake disc is possible.

[0014] It can be specified that the length of the helical engagement portion between the bolt and the internal component, along the direction of rotation, is at least 25% of the length of the cylindrical section along the direction of rotation. The corresponding helical engagement portion is thus able to support the significant torque caused by the force acting transversely to the cylindrical axis of the relevant bolt.

[0015] It can be specified that the second brake disc has multiple circular perforations, each through which an assigned bolt passes. This creates a torsional-resistant connection between the bolts and the second brake disc. When the brake is open, this ensures that the second brake disc can move slightly radially about the axis of rotation, thereby preventing noise generation during operation.

[0016] It can be specified that the circular perforation matches the cylindrical section of the bolt with a clearance. The aforementioned clearance is preferably designed to be as small as possible, so that surface pressure is minimized during contact between the perforation and the bolt. However, the lower limit for the clearance arises from the requirement that the second brake disc should be able to move freely along the axis of rotation relative to the bolt without jamming when the brake is engaged.

[0017] A fluid distributor can be configured to be torsionally connected to an external element about a rotation axis, wherein the fluid distributor is supported on an internal element along the direction of the rotation axis, wherein at least a portion of a second brake disc is arranged around the fluid distributor, wherein these second brake discs are respectively positioned directly opposite the fluid distributor at intervals. This allows for the saving of structural space.

[0018] It goes without saying that the features mentioned above and explained below can be used not only in the combinations described, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0019] The invention will now be explained in more detail with the aid of the accompanying drawings. Wherein: Figure 1 A longitudinal section of a hydrostatic rotating machine according to the invention is shown; Figure 2 It shows according to Figure 1 A perspective view of a hydrostatic rotating machine, in which the portion of the external components carrying the fluid distributor has been removed; Figure 3 A perspective view of the bolt is shown; Figure 4 A perspective view of the internal components along with the bolts is shown; and Figure 5 It shows according to Figure 1 A section of the rotating machinery in the region of the bolt, which is subject to hydrostatic forces. Detailed Implementation

[0020] Figure 1 A longitudinal section of a hydrostatic rotating machine 10 according to the invention is shown. The section includes the axis of rotation 11 and extends centrally through the piston 33. The hydrostatic rotating machine 10 includes an internal element 30 and an external element 20, which are rotatable relative to each other about the axis of rotation 11. Currently, they are supported on each other by means of two rotary bearings 35. The external element 20 forms the stator 21 of the hydrostatic rotating machine 10. A cam working surface 22 is constructed on the inner circumferential surface of this external element, which extends wavyly around the axis of rotation 11. The piston 33 abuts against the cam working surface 22 by a rotatable roller 36. It should be noted here that the current... Figure 1 and 4 This shows the piston fully engaged, thus not resting against the cam working surface 22, contrary to its operational state. The piston 33 is received in the cylinder 32 of the internal element 30 in a manner that allows for radial reciprocating motion along the axis of rotation 11. The internal element 30 currently forms the rotor 31 of the hydrostatic rotating machinery 10. It extends from the external element 20 via a drive shaft head 34.

[0021] A separate fluid distributor 23 is torsionally connected to the external element 20 about the axis of rotation 11 and is supported on the internal element along the direction of the axis of rotation 11. The cylinder 32 is thus connected to two working joints 12 via the fluid distributor 23, such that the rotational motion of the rotor 31 is accompanied by fluid exchange between the two working joints 12. During operation, the hydrostatic rotating machinery 10 preferably uses a fluid. The fluid is preferably a liquid, and most preferably hydraulic oil.

[0022] The hydrostatic rotating machinery 10 is equipped with a brake 40, which is configured as a multi-disc brake. The brake 40 includes a brake piston 44 capable of linear movement along the rotation axis 11. The brake piston 44 is pre-tensioned by a spring 45 to a closed position, in which rotational movement of the rotor 31 is stopped. The brake 40 can be released by applying pressure to the brake chamber 46.

[0023] Figure 2 It shows according to Figure 1 A perspective view of a hydrostatic rotating machine 10, wherein the portion of the external element 20 carrying the fluid distributor is removed. A brake 40 includes a plurality of first brake discs 41, which are torsionalally connected to the external element 20 about a rotation axis 11, wherein the first brake discs are movable along the direction of the rotation axis 11. Each first brake disc 41 has a plurality of radially outwardly pointing protrusions 47 about the rotation axis 11, which are shape-fitted into assigned slots 24 on the external element 20.

[0024] The second brake disc 42 is torsionally connected to the internal element 30 about the axis of rotation 11, wherein the second brake disc is movable along the direction of the axis of rotation 11. This connection is made by multiple, currently eight, bolts 50, which are preferably arranged evenly around the axis of rotation 11. The protrusions 47, as explained above, are arranged so evenly around the axis of rotation 11 that the bolts 50 and the distributed protrusions 47 are on a common imaginary radial ray about the axis of rotation 11.

[0025] The first and second brake discs 41 and 42 are arranged alternately along the direction of the rotation axis 11, thereby creating a multi-disc brake.

[0026] Figure 3 A perspective view of bolt 50 is shown. Each bolt 50 extends along a cylinder axis 58 oriented parallel to the axis of rotation. It has a first end 51 with an external thread 53, which is screwed into the internal thread of an internal component. A cylindrical section 54, formed cylindrically about the cylinder axis 58, is adjacent to the external thread 53. A second end 52 of the bolt 50, opposite the first end 51, has a form-locking device 55, which is currently configured as an external hexagon. A screwdriver can be placed there to screw the bolt 50 into the internal component with the necessary torque. The form-locking device 55 is configured such that it does not obstruct the insertion of the second brake disc. In particular, the maximum diameter of the form-locking device is at most the same as the diameter of the cylindrical section 54.

[0027] Bolt 50 is preferably designed to withstand a large force when brake 40 is closed, without significant bending.

[0028] Therefore, the threaded connection at the first end 51 is preferably designed to support torque. For this purpose, the length of the helical engagement 56 is at least 25% of the length of the cylindrical section 57. The outer diameter of the external thread 53 is preferably constructed to be smaller than the outer diameter of the cylindrical section 54, with a countersunk portion 59 arranged at the corresponding transition. The corresponding threaded connection is preferably designed such that the axial helical force is supported on the internal element in the region of the countersunk portion 59.

[0029] Figure 4 A perspective view of the internal components 30 together with the bolts 50 is shown. Pistons with rollers 36 are evenly distributed around the axis of rotation 11. Bolts 50 are also evenly distributed around the axis of rotation 11, wherein they are arranged circumferentially between two directly adjacent pistons 33.

[0030] In addition, Figure 4 As can be seen, bolt 50 is screwed into the remaining portion of the internal component 30 until the countersunk portion (in Figure 3 (See attached figure 59), making the cylindrical section (in...) Figure 3 (See attached figure 54) Extends to the remainder of the internal element 30.

[0031] In addition, Figure 4 As can be seen, the swivel bearing 35 is constructed as a mitered ball bearing and is equipped with a cage.

[0032] Figure 5 It shows according to Figure 1The section of the rotating machinery under hydrostatic force is located in the region of bolt 50. The section includes the axis of rotation and extends centrally through the bolt 50 shown. A first brake disc 41 and a second brake disc 42 can be seen, arranged alternately side-by-side along the axis of rotation. The second brake disc 42 has a circular perforation 43 for each bolt 50, which slightly matches the bolt 50 with a gap. A cylindrical section 54 of the bolt 50 passes through the aforementioned perforation 43, such that the braking force acting during operation is supported on the cylindrical section 54.

[0033] In addition, Figure 5 As can be seen from the pressure ring 48, the force of the brake piston is transmitted to the first brake disc 41 and the second brake disc 42 through the pressure ring.

[0034] List of reference numerals in the attached diagram: 10. Hydrostatic Rotating Machinery 11. Axis of rotation 12 Working joints 20 External Components 21 Stator 22 Cam working surface 23 Fluid distributor 24 slots 30 Internal Components 31 Rotor 32 cylinders 33 Pistons 34 Drive shaft head 35 Rotary bearing 36 rollers 40 Brake 41 First Brake Disc 42 Second Brake Disc 43. Circular perforation 44 Brake piston 45 springs 46 Braking chamber 47. Protrusion 48 Pressure Ring 50 bolts 51 First end 52 Second end 53 External thread 54 Cylindrical section 55 Shape-locking devices 56. Length of the spiral fitting portion 57. Length of the cylindrical section 58 cylinder axis 59. Sinking section

Claims

1. A hydrostatic rotating machine (10) having internal elements (30) and external elements (20), the internal elements and the external elements being coaxial about a rotation axis (11) and rotatable relative to each other, wherein one of these elements (30, 20) is a rotor (31) and the other of these elements (20, 30) is a stator (21), wherein a piston (33) movable in a cylinder (32) is capable of cooperating with a cam working surface (22) such that the rotational motion of the rotor (31) is accompanied by the reciprocating motion of the piston (33), wherein a brake (40) is provided, the brake being designed to prevent the rotational motion of the rotor (31) relative to the stator (21), wherein the brake (40) has a plurality of first brake discs (41) and a plurality of second brake discs (42) arranged alternately along the rotation axis (11), wherein the first brake discs (41) are torsionally connected to the external element (20) about the rotation axis (11). Its features are, At least two bolts (50) are provided, each extending parallel to the axis of rotation (11), wherein the bolts are fixedly connected to the internal element (30) at a first end (51) pointing in a direction along the axis of rotation (11), wherein each bolt (50) passes through all the second brake discs (42), such that the second brake discs (42) are connected to the internal element (30) with resistance to torsion about the axis of rotation (11).

2. The hydrostatic rotating machinery (10) according to claim 1. The number of bolts (50) is equal to the number of pistons (33).

3. The hydrostatic rotating machinery (10) according to claim 2. The piston (33) and the bolt (50) are arranged evenly around the axis of rotation (11), and the bolt (50) is arranged between the piston (33) in a circumferential direction about the axis of rotation (11).

4. The hydrostatic rotating machinery (10) according to any one of the preceding claims. Each bolt (50) on all first brake discs (41) is provided with a radially outward protrusion (47), wherein the protrusion (47) is embedded in a separately assigned groove (24) on the outer element (20).

5. The hydrostatic rotating machinery (10) according to any one of the preceding claims. The bolts (50) are each made as separate components, which are screwed into the internal element (30) at the first end (51).

6. The hydrostatic rotating machinery (10) according to claim 5. The bolt (50) is provided with a shape-locking device (55) at a second end (52) opposite to the first end (51) along the direction of the rotation axis (11), the shape-locking device being configured to engage with the spiral tool in a shape-locking manner.

7. The hydrostatic rotating machinery (10) according to any one of the preceding claims. The bolt (50) has a cylindrical section (54) outside the inner element (30), the cylindrical section having its cylindrical axis arranged parallel to the axis of rotation (11), wherein the second brake disc (42) is arranged in the region of the cylindrical section (54).

8. The hydrostatic rotating machinery (10) according to claim 7, in the case of its retraction of claim 5, The length of the helical fitting (56) between the bolt (50) and the internal component (30) along the direction of the rotation axis (11) is at least 25% of the length of the cylindrical section (57) along the direction of the rotation axis (11).

9. The hydrostatic rotating machinery (10) according to any one of claims 7 or 8. The second brake disc (42) has a plurality of circular through holes (43), which are respectively penetrated by assigned bolts (50).

10. The hydrostatic rotating machinery (10) according to claim 9. The circular perforation (43) therein matches the cylindrical section (54) of the bolt (50) with a gap.

11. The hydrostatic rotating machinery (10) according to any one of the preceding claims. A fluid distributor (23) is provided therein, which is torsionally connected to an external element (20) about a rotation axis (11), wherein the fluid distributor is supported on an internal element (30) along the direction of the rotation axis (11), wherein at least a portion of the second brake discs (42) are arranged around the fluid distributor (23), wherein these second brake discs are directly opposite the fluid distributor (23) at a distance.

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