Motors: expansible chamber type – Three or more cylinders arranged in parallel radial or... – Radially disposed cylinders
Reexamination Certificate
1998-06-19
2001-02-13
Freay, Charles G. (Department: 3746)
Motors: expansible chamber type
Three or more cylinders arranged in parallel radial or...
Radially disposed cylinders
C417S273000
Reexamination Certificate
active
06186046
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a hydraulic motor comprising:
a fixed case;
a reaction member secured to the case;
a cylinder block mounted to rotate relative to said reaction member about an axis of rotation and comprising a plurality of cylinder and piston assemblies disposed radially relative to the axis of rotation and capable of being fed with fluid under pressure, the cylinder block having a communication face perpendicular to the axis of rotation; and
an internal fluid distributor secured to the case to prevent rotation about the axis of rotation and having a distribution face perpendicular to the axis of rotation and suitable for being pressed against the communication face of the cylinder block, and a first connection face, said distributor including distribution ducts which extend between the first connection face and the distribution face;
the case having a “distribution cover” portion situated around the distributor and presenting a second connection face situated facing the first connection face and having feed and exhaust ducts opening out therein, the distribution ducts of the distributor thus being suitable for putting the cylinders into communication with the main fluid feed and exhaust ducts.
BACKGROUND OF THE INVENTION
In that type of motor, the distributor and the distribution cover belong to the stator and are generally secured to each other and constrained to rotate one with the other so as to obtain a relative angular position that is very accurate between the distributor and the reaction member which is itself secured to rotate with the distribution cover. To secure the parts in this way and obtain such accurate positioning, various systems have been proposed. Thus, the distributor has been provided with a radial flange extending between the cylinder block and the distribution cover, and an axial peg has been provided to secure the flange to the distribution cover. Other systems using tenons and notches have also been provided.
Although those various solutions do indeed make it possible to ensure positioning in rotation, at least those which use the radial flange suffer from the major drawback of requiring special machining of the distributor and of thereby increasing manufacturing costs. In addition, the presence of the flange increases the axial length of the motor.
Furthermore, it is necessary to take very great care in assembling the motor. In particular the distributor must be accurately positioned in the distribution cover and the regions of the first and second connection faces respectively connected to the feed duct and to the exhaust duct must naturally be completely isolated form each other, which means that sealing gaskets must be provided between the first and second connection faces, and said gaskets must be accurately positioned.
When assembly is complete, it is necessary to make provision for a small amount of axial movement between the distributor and the distribution cover, thus enabling the distribution face to bear against the communication face of the cylinder block.
OBJECT AND SUMMARY OF THE INVENTION
The present invention seeks to provide a simplified system making it possible to ensure accurate constraint in rotation of the distributor and of the distribution cover while also facilitating assembly of the motor, i.e., in particular, simplifying assembly of the subassembly constituted by the distributor and the distribution cover relative to the cylinder block, while holding the distributor axially in the distribution cover and simultaneously making axial movement of the distributor possible as is required in operation, but doing so to an extent that is only just sufficient, so as to guarantee that the sealing gaskets stay in their housings without any risk of being damaged.
This object is achieved by the fact that the distribution cover and the distributor are provided respectively with first and second axial parts in which there are formed at least a first substantially radial housing and at least a second substantially radial housing defining at least a first pair of housings situated facing each other, by the fact that the first housing has a first wall element situated on the side of said housing that is axially adjacent to the cylinder block while the second housing has a second wall element situated on the side of said second housing that is axially remote from the cylinder block by the fact that it includes a locking pin for preventing rotation disposed in said first and second housings so as to extend substantially radially, by the fact that one of the first and second housings has axial dimensions measured along the axis of rotation of the motor that are greater than the corresponding dimensions of the pin to enable the distributor to move relative to the distribution cover, and by the fact that one of the first and second housings is a substantially radial through passage via which the pin can be put into place.
It will be understood that by very simple machining consisting in providing the first and second housing respectively in the axial portion of the distribution cover and in the axial portion of the distributor and by using a single pin, the distributor is prevented form rotating relative to the distribution cover, In addition, the pin also provides axial locking since when maximum axial clearance is obtained between the distributor and the distribution cover, the pin co-operates in abutment with the first and second wall elements to prevent the distributor from moving relative to the distribution cover in the axial direction tending to bring the distributor closer to the cylinder block, thereby greatly simplifying assembly.
To assemble the motor, after the shaft has been assembled together with its bearings, a case portion, and distributor and the distribution cover together using the pin so as to make up a “distribution subassembly”, and then to bring the subassembly up to the cylinder block.
While the distributor is being brought up in this way, with its distribution face facing generally downwards, the distributor is prevented form rotating and is held axially inside the distribution cover by the pin which is in abutment simultaneously against both the first and the second wall elements, so it suffices to hold the distribution cover in order to control installation of the distribution subassembly on the cylinder block until the distribution and communication faces come into contact.
In an advantageous embodiment, the first and second axial parts are formed respectively in an internal axial extension of the distribution cover which has the first housing passing therethrough and in an axial part of the distributor having an axially outer periphery in which the second housing forms a recess, and the motor includes means for enabling the locking pin to be inserted in said first and second housings from the radially outer side of said internal axial extension.
In this embodiment, it is thus the first housing which constitutes a through passage, while the second housing is merely a recess. The pin is installed form the radially outer side of the extension of the distribution cover, which side is often the most easily accessible.
REFERENCES:
patent: 4404896 (1983-09-01), Allart et al.
patent: 4704948 (1987-11-01), Wusthof et al.
patent: 5186094 (1993-02-01), Allart et al.
patent: 5261318 (1993-11-01), Allart
patent: 5632191 (1997-05-01), Lemaire et al.
patent: 2533965 (1986-12-01), None
Allart Bernard
Bigo Louis
Perot Marc
Freay Charles G.
Ladas & Parry
Poclain Hydraulics
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