The present invention relates to the field of hydraulic devices. More precisely, the present invention relates to the field of hydraulic devices with radial pistons.
The hydraulic device 1 comprises a shaft 2 positioned along an axis of rotation 3 and a cover 4 forming a casing element, free to rotate with respect to one another.
The hydraulic device 1 additionally comprises an assembly including a multi-lobe cam 5, a cylinder block 6 and a distributor 7.
The cam 5 is formed from a ring provided in the cover 4 and comprises, on a radially internal surface, a series of lobes with a sinusoidal type shape overall, distributed evenly around the rotation axis 3.
The cylinder block 6 is placed in the interior of the ring forming the cam 5 and defines a plurality of cylinders oriented radially with respect to the axis of rotation 3 and leading to a peripheral external face of the cylinder block 6 facing the cam 5. A piston is mounted radially sliding respectively in each of the cylinders. Each piston bears on the radially internal surface of the cam 5.
The distributor 7 is adapted to apply a fluid under pressure in a controlled manner to each of the pistons, more precisely in an internal chamber of the cylinders adjoining the pistons, so that the successive bearing of the pistons on the lobes of the cam 5 drives the relative rotation of the cylinder block 6 and of the elements which are linked to it with respect to the cam 5, and therefore to the cover 4, or conversely. To this end, there exists an asymmetry between the number of lobes formed on the cam 5 and the number of associated pistons located in the cylinder block 6.
The hydraulic device 1 also comprises two conical roller bearings 8a and 8b by means of which the shaft 2 and the cover 4 are mounted so as to rotate with respect to one another. To this end, the bearings 8a and 8b are mounted in radial contact with the shaft 2 on the one hand and the cover 4 on the other hand, and are arranged on either side of the assembly formed by the cam 5, the cylinder block 6 and the distributor 7. Each bearing 8a and 8b is also mounted between two axial abutment surfaces provided in the shaft 2 and the cover 4.
However, the conical roller bearings 8a and 8b must be mounted without axial clearance, so as to ensure that they can take up the axial forces in the hydraulic device 1 and avoid having the bearings 8a and 8b become detached.
For this purpose, it is necessary in particular to place pre-loading spacers 9a or elastic rings 9b in axial contact with the bearings 8a and 8b. The pre-loading spacers 9a or the elastic rings 9b are for example in axial contact with the bearings 8a and 8b on the one hand, and with the axial abutment surface of the cover 4 on the other hand, so as to press the bearings 8a and 8b against the axial abutment surface of the shaft 2, and thus ensure an assembly without axial clearance of the conical roller bearings 8a and 8b in the hydraulic device 1.
However, the pre-loading spacers 9a or the elastic rings 9b generate a pre-loading force which induces a resistance at the bearings 8a and 8b, thus reducing their lifetime.
The use of bearings with conical rollers thus makes it compulsory to replace them frequently.
Moreover, the rollers of the bearings 8a and 8b are conventionally immersed in lubricating oil designed to reduce friction between the rollers and the inner and outer rings of the bearings 8a and 8b.
However, by rolling on the inner and outer rings of the bearings 8a and 8b, the rollers displace the lubricating oil, thus generating additional resistance at the bearings 8a and 8b.
There exists therefore a need to reduce the resistance induced by conical roller bearings 8a and 8b of the hydraulic device 1.
The present invention has as its purpose to reduce the previously described problems by proposing a hydraulic device with radial pistons comprising:
Preferably, the shaft comprises an axial abutment surface against which the cylinder block is pressed when the distributor exerts a thrust force against the cylinder block.
Preferably, the second mechanical bearing is a conical roller bearing or an oblique contact ball bearing.
Preferably, the second mechanical bearing comprises an external cage and an internal cage between which the rolling elements are mounted, axially opposite sides of the internal cage and of the external cage being respectively mounted in axial contact with the shaft and the cover, so as to take up the thrust force.
Preferably, the hydraulic device comprises a sleeve mounted in rotation around the shaft, by means of which the second mechanical bearing is mounted in radial contact and in axial contact with the shaft.
Preferably, the set of second bearings comprises a radial contact ball bearing and a ball thrust bearing.
Preferably, the ball thrust bearing comprises a first cage and a second cage between which are mounted the balls, and the radial contact ball bearing of the assembly comprises an internal cage and an external cage between which are mounted the balls, the first cage being mounted in axial contact with the shaft, and axially opposite sides of the external cage of the radial contact ball bearing of the assembly being respectively mounted in axial contact with the second cage of the ball thrust bearing and the cover, so as to take up the thrust force.
Preferably, the set of second mechanical bearings comprises a needle bearing and a cylindrical roller ball thrust bearing.
Preferably, the cylindrical roller ball thrust bearing comprises a first cage and a second cage between which cylindrical rollers are mounted, the first cage of the cylindrical roller ball thrust bearing being mounted in axial contact with the cover and the second cage of the cylindrical roller ball thrust bearing being mounted in axial contact with the cylinder block, radially opposite sides of the first cage and of the second cage of the cylindrical roller ball thrust bearing being respectively mounted in radial contact with the cover and the cylinder block.
Preferably, the needle bearing comprises an internal cage and an external cage between which the needles are mounted, axially opposite sides of the internal cage of the needle bearing being respectively mounted in axial contact with the shaft and the cover, and axially opposite sides of the external cage of the needle bearing being mounted in axial contact with the cover.
Preferably, the hydraulic device comprises a sleeve mounted in rotation around the shaft by means of which the needle bearing is mounted in radial contact and in axial contact with the shaft.
Preferably, the set of second mechanical bearings is mounted without axial clearance between the shaft and the cover.
Preferably, the external cage of the second mechanical bearing is mounted in axial contact with the cover by means of a pre-loading spacer, so as to ensure assembly without radial clearance of the set of second mechanical bearings between the shaft and the cover.
Preferably, the external cage of the radial contact ball bearing of the set is mounted in axial contact with the second cage of the ball thrust bearing by means of a pre-loading spacer, so as to ensure assembly without axial clearance of the set of second mechanical bearings between the shaft and the cover.
Preferably, the set of second mechanical bearings is positioned around a first side of the distribution assembly arranged in the thrust direction of the distributor against the cylinder block.
Preferably, the hydraulic device comprises two first mechanical bearings arranged on either side of the distribution assembly, said first mechanical bearings being radial contact ball bearings.
Preferably, the first mechanical bearing is positioned from a second side of the distribution assembly arranged opposite to the thrust direction of the distributor against the cylinder block.
Preferably, the first mechanical bearing comprises an internal cage and an external cage between which are mounted the balls, axially opposite sides of the external cage and of the internal cage being respectively mounted in axial contact with the cover and the shaft, so as to obtain a closure of the axial forces by the cover.
Preferably, the set of second mechanical bearings is positioned on the second side of the distribution assembly arranged opposite to the thrust direction of the distributor against the cylinder block.
Preferably, the first mechanical bearing is positioned on the first side of the distribution assembly arranged in the thrust direction of the distributor against the cylinder block.
Preferably, the first mechanical bearing comprises and internal cage and an external cage between which are mounted the balls, axially opposite sides of the internal cage being both mounted in axial contact with the shaft so as to ensure closure of the forces by the shaft.
Preferably, the shaft is hollow and configured to be mounted around a shaft, particularly a differential shaft, said hydraulic device comprising a first ring seal mounted in radial contact with an external surface of one end of the shaft on the one hand, and the cover on the other hand, and a second ring seal mounted in radial contact with an internal surface of said end of the shaft on the one hand and configured to be mounted in radial contact with the shaft on the other hand.
Preferably, the hydraulic device comprises a lock ring comprising a first and a second annular portion connected together by an intermediate portion, the first annular portion of the lock ring being mounted on the external surface of the end of the shaft, and the first ring seal being mounted in radial contact with the end of the shaft by means of said first annular portion, the second annular portion of the lock ring extending from the intermediate portion distancing itself from the end of the shaft, and the second ring seal being mounted in radial contact with the end of the shaft by means of said second annular portion.
Preferably, the internal surface of the end of the shaft is provided with a shoulder forming a space which accommodates the second ring seal.
Preferably, the hydraulic device also comprises an annular band mounted on the external surface of the shaft and by means of which the first ring seal is in radial contact with the end of the shaft.
Preferably, the external surface of the end of the shaft is provided with a shoulder accommodating the first portion of the lock ring or the annular band.
Preferably, the first and the second ring seals are arranged one around the other overall.
Other features, aims and advantages of the invention will be revealed by the description that follows, which is purely illustrative and not limiting, and which must be read with reference to the appended drawings, wherein:
The hydraulic apparatus 10 comprises a shaft 12 positioned along the axis of rotation 11 and a cover 13 forming a casing element. The shaft 12 and the cover 13 are free to rotate with respect to one another. The cover 12 is preferably fixed, while the shaft 12 is free to rotate around the axis of rotation 11. Preferably, the hydraulic device 10 is configured to transmit only pure torque. In particular, the hydraulic device 10 does not transmit an axial force, generated for example by gearing thrust, nor a radial force, generated for example by the pressure of a wheel.
The hydraulic device 10 also comprises a distribution assembly including a multi-lobe cam 14, a cylinder block 15 and a distributor 16.
The cam 14 is formed by a ring arranged coaxially with the axis of rotation 11 and provided in the cover 13. The ring of the cam 14 is integral with the cover 13. The cam 14 comprises, on a radially internal surface, a series of lobes distributed evenly around the axis of rotation 11. Each of the lobes has a sinusoidal type shape overall.
The cylinder block 15 is mounted on the shaft 12 and is placed inside the ring forming the cam 14. It defines a plurality of cylinders oriented radially with respect to the axis of rotation 11 and leading to an external peripheral face of the cylinder block 15 facing the cam 14. A piston is mounted so as to slide radially respectively in each of the cylinders. Each piston bears on the radially internal surface of the cam 14.
The distributor 16 is mounted on the shaft 12, on a first side of the cylinder block 15 according to the axis of rotation 11. The distributor 16 is adapted to successively apply a fluid under pressure in a controlled manner to each of the pistons, more precisely in an internal chamber of the cylinders adjoining the pistons, so that the successive thrust of the pistons on the lobes of the cam 14 brings about relative rotation of the cylinder block 15 and of the elements linked to it, particularly the shaft 12, with respect to the cam 14 and therefore to the cover 13, or conversely. To this end, there exists an asymmetry between the number of lobes formed on the cam 14 and the number of associated pistons situated in the cylinder block 15.
The distributor 16 is also configured to exert a thrust force P against the cylinder block 15 along the axis of rotation 11. Thus, the distributor 16 and the cylinder block 15 are in fluid-tight contact with one another. The hydraulic device 10 includes for example an elastic return element, such as a tension or compression spring, to press the distributor 16 against the cylinder block 15.
In the examples illustrated in
In the examples illustrated in
The hydraulic device 10 also comprises a first mechanical bearing 21 and a set 22 of second mechanical bearings comprising at least one second mechanical bearing by means of which the shaft 12 and the cover 13 are mounted in rotation with respect to one another. To this end, the first mechanical bearing 21 and the second mechanical bearing(s) 22 are mounted in radial contact with the shaft 12 on the one hand and the cover 13 on the other hand.
The set 22 of second mechanical bearings is configured to take up the thrust force P exerted by the distributor 16.
The first mechanical bearing 21 is a radial contact ball bearing comprising an external cage and an internal cage, between which are mounted the balls. What is meant by a “radial contact ball bearing” is a ball bearing wherein the resultant of the contact force of the external cage and of the internal cage has only a radial component, in contrast for example to an oblique contact ball bearing the resultant whereof will have both a radial component and an axial component. The first mechanical bearing 21 is for example a deep groove ball bearing. The radial contact ball bearing 21 is configured to take up axial forces of low amplitude compared to the thrust force P.
In the examples illustrated in
In the example illustrated in
The conical roller bearing 22a is arranged so that the axial resultant of the thrust force exerted by the conical rollers on the internal cage of the conical roller bearing 22a is in the opposite direction to the thrust force P of the distributor 16 on the cylinder block 15. In other words, the conical roller bearing 22a is positioned so that its center of thrust C on the axis of rotation 11 is offset toward the distribution assembly.
In the example illustrated in
The oblique contact ball bearing 22b is positioned so that the axial resultant of the thrust force P exerted by the balls on the internal ring of the oblique contact ball bearing 22b is in the direction opposite to the thrust force P of the distributor 16 on the cylinder block 15. In other words, the oblique contact ball bearing 22b is positioned so that its center of thrust C on the axis of rotation 11 is offset toward the distribution assembly.
In the examples illustrated in
It will be understood that such an assembly makes it possible to ensure that the thrust force P exerted by the distributor 16 on the cylinder block 15, which is transmitted to the shaft 12, is taken up.
In the example illustrated in
In the example illustrated in
Thus, the set 22 of second mechanical bearings makes it possible to ensure that the thrust force P exerted by the distributor 16 on the cylinder block 15, which is transmitted to the shaft 12, is taken up.
Preferably, the set 22 of second mechanical bearing is mounted in the axial clearance between the shaft 12 and the cover 13, so as to ensure that the axial forces in the hydraulic device 10 are taken up and in particular to avoid having the set 22 of second mechanical bearings become detached.
In the examples illustrated in
In the example illustrated in
The pre-loading spacer 28, 29 or the dimensioning of the hydraulic device 10 without axial clearance, induce an axial preload of small amplitude comparatively to the thrust force P. As described hereafter, this force is taken up by the first mechanical bearing 21.
In the examples illustrated in
In the example illustrated in
In the example illustrated in
The conical roller bearing 22e is arranged so that the axial resultant of the thrust force P exerted by the conical rollers on the internal cage of the conical roller bearing 22e is in the opposite direction to the thrust force P of the distributor 16 on the cylinder block 15. In other words, the conical roller bearing 22e is positioned so that its center of thrust C on the axis of rotation 11 is offset to distance it from the distribution assembly.
In the example illustrated in
It will be understood that such an assembly makes it possible to take up the thrust force P exerted by the distributor 16 on the cylinder block 15, which is transmitted to the shaft 12.
In the example illustrated in
As illustrated in
For this purpose, the sealing device comprises a first ring seal 35 mounted in radial contact with an external surface of an end of the shaft 12, arranged on the side of the distributor 16 with respect to the cylinder block 15, on the one hand and the cover 13 on the other hand, and a second ring seal 37 mounted in radial contact with the internal surface of said end of the shaft 12 on the one hand and configured to be mounted in radial contact with the differential shaft 30 on the other hand.
In the variant illustrated in
The first annular portion 32 of the lock ring 31 is mounted on the external surface of the end of the shaft 12. The first ring seal 35 is mounted in radial contact with the first annular portion 32 of the lock ring 31 on the one hand, and with the cover 13 on the other hand, thus ensuring the fluid-tightness of the hydraulic device 10. The first ring seal 35 is therefore mounted in radial contact with the shaft 12 by means of the first annular portion 32 of the lock ring 31. The first annular portion 32 of the lock ring 31 thus serves as a friction surface for the first ring seal 35. The first ring seal 35 is placed for example against the intermediate portion 34 of the lock ring 31. A shoulder 36 is provided for example at the end of the shaft 12 to accommodate the first annular portion 32 of the lock ring 31.
The second annular portion 33 of the lock ring 31 extends from the intermediate portion 34 distancing itself from the end of the shaft 12. The second ring seal 37 is mounted in radial contact with the second annular portion 33 of the lock ring 31, on the one hand, and with the differential shaft 30 on the other hand, thus ensuring the seal between the differential shaft 30, and thus the differential, and/or the gearbox, and the shaft 12 of the hydraulic device 10. The second ring seal 37 is therefore mounted in radial contact with the shaft 12 by means of the second annular portion 33 of the lock ring 31. The first and second ring seals 35, 37 are mounted on opposite faces of the lock ring 31. The second annular portion 33 of the lock ring 31 forms a housing around the differential shaft 30 to accommodate the second ring seal 37. The differential shaft 30 has a collar 38 for example on which is mounted the second ring seal 37.
In one embodiment (not shown), the two annular portions 32 and 33 of the lock ring 31 have the same diameter.
As a variant, the second annular portion 33 of the lock ring 31 has a smaller diameter than the diameter of the first annular portion 32 of the lock ring 31.
In the variant illustrated in
The variant illustrated in
Moreover, to gain compactness in the two variants, the first and the second ring seals 35, 37 can be positioned at least partially one around the other.
The hydraulic device 100 comprises a shaft 112 positioned along the axis of rotation 111 and a cover 113 forming a casing element. The shaft 112 and the cover 113 are free to rotate with respect to one another. The cover 113 is preferably fixed, while the shaft 112 is free to rotate around the axis of rotation 111. Preferably, the hydraulic device 100 is configured to transmit only pure torque. In particular, the hydraulic device 100 does not transmit any axial force, generated by gear thrust for example, nor any radial force, generated for example by the pressure of a wheel.
The shaft 112 is a through shaft and can be disengaged. The opposite ends of the shaft 112 along the axis of rotation 111 are designed to be coupled to external shafts (not shown). To increase the transmission of torque between the external shafts and the shaft 112, the ends of the shaft 112 are provided with contact faces 137 designed to come into contact with the external shafts, which have undergone shot peening followed by a hardening surface treatment. Thus, the contact faces 137 are rough and constitute friction surfaces allowing a considerable torque to be transmitted between the shaft 112 and the external shafts.
In the examples illustrated in
The hydraulic device 100 is used for example as a motor for motor vehicles with hydrostatic and mechanical drive. During a mechanical drive phase, the hydraulic device 100 is disengaged and the shaft 112 is driven by the heat engine via a gearbox of the vehicle. In hydrostatic drive, the hydraulic device 100 is engaged and drives the shaft 112, the gearbox of the heat engine being in neutral in this case and the heat engine driving the pump supplying the oil flow required for the operation of the hydraulic device 100.
The hydraulic device 100 also comprises a distribution assembly comprising a multi-lobe cam 114, a cylinder block 115 and a distributor 116.
The cam 114 is formed from a ring arranged coaxially with the axis of rotation 111 and provided in the cover 113. The cam ring 114 is integral with the cover 113. The cam 114 comprises, on a radially internal surface, a series of lobes evenly distributed around the axis of rotation 111. Each of the lobes has a sinusoidal type overall shape.
The cylinder block 115 is mounted on the shaft 112 and is placed inside the ring forming the cam 114. It defines a plurality of cylinders oriented radially with respect to the axis of rotation 111 and leading to an external peripheral face of the cylinder block 115 facing the cam 114. A piston is mounted so as to slide radially respectively in each of the cylinders. Each piston bears on the radially internal surface of the cam 114.
The distributor 116 is mounted on the shaft 112, on a first side of the cylinder block 115 along the axis of rotation 111. The distributor 116 is adapted to apply a fluid under pressure in a controlled manner to each of the pistons, more precisely in an internal chamber of the cylinders adjoining the pistons, so that the successive pressure of the pistons on the lobes of the cam 114 drives the relative rotation of the cylinder block 115 and of the elements which are linked to it, particularly the shaft 112, with respect to the cam 114 and hence to the cover 113, or conversely. To this end, there exists and asymmetry between the number of lobes formed on the cam 114 and the number of associated pistons situated in the cylinder block 115.
The distributor 116 is also configured to exert a thrust force P against the cylinder block 115 along the axis of rotation 111. Thus, the distributor 116 and the cylinder block 115 are in fluid-tight contact with one another. The hydraulic device 100 comprises for example an elastic return element, such as a tension or compression spring, to press the distributor 116 against the cylinder block 115.
In the examples illustrated in
In the examples illustrated in
For this purpose, the clutch system comprises for example a fluted clutch ring 145 which, in the engaged position, mounted both on the shaft 112 and on the sleeve 130, so that the hydraulic device 100 drives in rotation both the shaft 112 and the sleeve 130 and which, in the disengaged position, is mounted only on the sleeve 130, so that the hydraulic device 100 drives only the rotation of the sleeve 130 and no longer that of the shaft 112, the sleeve 130 and the shaft 112 being free to rotate with respect to one another. In the engaged configuration, the fluted clutch ring 145 extend in part around the shaft 112, particularly the shoulder 117 of the shaft 112, and the first end of the sleeve 130. In the disengaged configuration, the fluted clutch ring 145 no longer extends around the first end of the sleeve 130. The fluted clutch ring 145 is configured to move from one configuration to another by translation along the axis of rotation 111. The fluted clutch ring 145 is for example controlled in translation by a control actuator of the clutch system. This makes it possible to couple or decouple the hydraulic device 100 from the shaft 112.
The hydraulic device 100 also comprises a set 121 of first mechanical bearings comprising at least one first mechanical bearing 121a, 121b and a set 122 of second mechanical bearings comprising at least one second mechanical bearing 122a, 122b,122c by means of which the shaft 112 and the cover 113 are mounted able to rotate with respect to one another. To this end, the first mechanical bearing(s) 121a, 121b and at least one of the second mechanical bearings 122a, 122b are mounted in radial contact with the shaft 112 on the one hand and the cover 113 on the other hand.
In the example illustrated in
The first mechanical bearings 121a, 121b are radial contact ball bearings each comprising an external cage and an internal cage between which are mounted the balls. The first mechanical bearings 121 are for example deep groove ball bearings. The radial contact ball bearings 121a, 121b are configured to take up axial forces with low amplitude with respect to the thrust force P.
The set 122 of second mechanical bearings is configured to take up the thrust force P exerted by the distributor 116.
In the example illustrated in
The conical roller bearing 122a is arranged so that the axial resultant of the thrust force exerted by the conical rollers on the internal cage of the conical roller gearing 122a is in the direction opposite to the thrust force P of the distributor 116 on the cylinder block 115. In other words, the conical roller bearing 122a is positioned so that its center of thrust C on the axis of rotation 111 is offset toward the distribution assembly.
The conical roller bearing 122a is in radial contact with the shaft 112 via the sleeve 130 on the one hand and with the cover 113 on the other hand.
Axially opposite sides of the internal cage of the second mechanical bearing 122a are respectively mounted in axial contact with the shaft 112 via the sleeve 130, and the cylinder block 115, which one side of the external cage of the second mechanical bearing 122a, opposite to the cylinder block 115 along the axis of rotation 111, is mounted in axial contact with the cover 113. A shoulder 131 is for example provided in the sleeve 130 so as to form an abutment surface against which the internal cage of the second mechanical bearing 122a is mounted in axial contact.
It will be understood that such an assembly makes it possible in fact to ensure that the thrust force P, exerted by the distributor 116 on the cylinder block 115, which is transmitted to the shaft 112, is taken up.
Preferably, the conical roller bearing 122a is mounted without axial clearance between the shaft 112 and the cover 113, so as to ensure that the axial forces in the hydraulic device 100 are taken up, and in particular to avoid having the conical roller bearing 122a become detached.
For this purpose, the hydraulic device 100 is for example dimensioned so that the conical roller bearing 122a is mounted without axial clearance between the latter and the shaft 112/the cover 113. As an alternative, an elastic ring 142 can be inserted into a groove provided in the sleeve 130 facing the side of the internal cage of the conical roller bearing in contact with the cylinder block 115, and a pre-loading spacer 143 is positioned between the elastic ring 142 and said side of the internal cage, so as to ensure the assembly of the conical roller bearing 122a without axial clearance. A shoulder 144 can also be provided in the cylinder block 115 to accommodate the elastic ring 142 and the pre-loading spacer 143.
In the example illustrated in
In addition, axially opposite sides of the internal cage of the first mechanical bearing 121b situated on a second side of the distribution assembly, opposite to the first side, are both mounted in axial contact with the shaft 112, while none of the axially opposed sides of the external cage is in axial contact with the cover 113 of the shaft 112. One of the axially opposite sides of the internal cage of the first mechanical bearing 121b is for example mounted in axial contact with the shaft 112 by means of an elastic ring 132 inserted in a groove provided in the shaft 112.
According to a variant of the hydraulic device 100 illustrated in
In the example illustrated in
The internal cage of the needle bearing 122b is in radial contact with the shaft 112 via the sleeve 130, while its external cage is in direct radial contact with the cover 113.
Axially opposite sides of the internal cage of the needle bearing 122b are respectively mounted in axial contact with the shaft 112, via the sleeve 130 and for example the shoulder 131 provided in said sleeve 130, and the cover 113, for example by means of an elastic ring 133 inserted into a groove provided in the cover 113. Axially opposite sides of the external cage of the needle bearing 122b are both mounted in axial contact with the cover 113, for example by means of a shoulder 134 forming an abutment surface provided in the cover 113 on the one hand, and on the other hand by means of the elastic ring 133 of the cover 113.
Thus the needle bearing 122b makes it possible to align the sleeve 130 and the cover 113.
The first cage of the cylindrical roller thrust bearing 122c is mounted in axial contact with the cover 113 and the second cage of the cylindrical roller thrust bearing 122c is mounted in axial contact with the cylinder block 115.
Radially opposite sides of the first cage and of the second cage, corresponding respectively to the radially external and radially internal sides of the first cage and of the second cage of the cylindrical roller thrust bearing 122c are respectively mounted in radial contact with the cover 112 and the cylinder block 115. For this purpose, a groove 135 is for example provided in the cover 113 so as to receive the first cage of the cylindrical roller thrust bearing 122c. In addition, a shoulder 136 is for example provided in the cylinder block 115 so as to receive the second cage of the cylindrical roller thrust bearing 122c.
Thus, the cylindrical roller thrust bearing 122c makes it possible to absorb the thrust force P exerted by the distributor 116 on the cylinder block 115, which is transmitted to the shaft 112.
Preferably, the cylindrical roller thrust bearing 122c is mounted without axial clearance between the cover 113 and the cylinder block 115, so as to ensure that the axial loads in the hydraulic device 100 are taken up and in particular to avoid that the cylindrical roller thrust bearing 122c becomes detached. For this purpose, the hydraulic device 100 is dimensioned so that the cylindrical roller thrust bearing 122c is mounted without axial clearance between the latter and the cover 113/the cylinder block 115.
Moreover, so as to minimized the bulk of the hydraulic device 100, the cylindrical roller thrust bearing 122c has an inner diameter greater than the inner diameter of the needle bearing 122b so that the two bearings 122b, 122c are arranged concentrically, the cylindrical roller thrust bearing 122c extending or example at least partially around the needle bearing 122b.
The hydraulic devices 10, 100 illustrated in
Number | Date | Country | Kind |
---|---|---|---|
14 62670 | Dec 2014 | FR | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2015/080353 | 12/17/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2016/097216 | 6/23/2016 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3593621 | Praddaude | Jul 1971 | A |
3760691 | Kleckner | Sep 1973 | A |
4404896 | Allart | Sep 1983 | A |
4532854 | Foster | Aug 1985 | A |
4898076 | Bigo | Feb 1990 | A |
5186094 | Allart | Feb 1993 | A |
5836231 | Leinonen | Nov 1998 | A |
6443047 | Cunningham | Sep 2002 | B1 |
6843162 | Shrive | Jan 2005 | B2 |
Number | Date | Country |
---|---|---|
2588616 | Apr 1987 | FR |
2996268 | Apr 2014 | FR |
Entry |
---|
Poclain Hydraulics Industrie, “French Preliminary Search Report and Written Opinion,” FR Application No. 1462670 (dated Aug. 5, 2015) (with English translation cover sheet). |
Poclain Hydraulics Industrie, “International Search Report and Written Opinion,” PCT Application No. PCT/EP2015/080353 (dated Mar. 18, 2016) (with English translation cover sheet). |
Number | Date | Country | |
---|---|---|---|
20170335831 A1 | Nov 2017 | US |