1. Field of the Invention
This invention relates to a chuck assembly, more particularly to a chuck assembly with a sealing member for preventing hydraulic fluid from entering into a clearance between a shaft and a sleeve of the chuck assembly.
2. Description of the Related Art
U.S. Pat. No. 6,497,417 discloses a conventional chuck assembly 1 that includes a housing 10 defining an inner space, a shaft 11 mounted co-axially and rotatably in the inner space and defining a chuck-receiving space 13 which has an enlarged end portion defining a piston-receiving chamber 131, a sleeve 12 secured to the housing 10 and sleeved on the shaft 11 so as to define a clearance 14 therebetween, a bearing unit 18 disposed between the sleeve 12 and the shaft 11, a chuck unit mounted in the chuck-receiving space 13 and including a plurality of jaws 16 for holding a workpiece (not shown), and a piston 15 mounted in the piston-receiving chamber 131, displaceable in an axial direction, and connected to the jaws 16 in such a manner that axial displacement of the piston 15 results in radial displacement of the jaws 16. The piston 15 subdivides the piston-receiving chamber 131 into first and second compartments 1311, 1312. A fluid channel 17 is formed in the chuck assembly 1, is in fluid communication with the first compartment 1311 of the piston-receiving chamber 131, and is adapted to be connected to a hydraulic fluid supply (not shown) so as to permit flow of pressurized hydraulic fluid into the first compartment 1311, thereby resulting in axial displacement of the piston 15.
Due to a large amount of the pressurized hydraulic fluid penetrating through the clearance 14, which can result in contamination of the chuck unit and the workpiece and a significant loss of the hydraulic fluid, a plurality of fluid passages 19 are required to be formed in the sleeve 12 and the housing 10, and a plurality of hydraulic fluid collectors (not shown) are required for collecting the hydraulic fluid. As a consequence, the dimensions of the chuck assembly 1 are increased considerably.
The disclosure of U.S. Pat. No. 6,497,417 is incorporated herein by reference.
The object of the present invention is to provide a chuck assembly with a sealing member that is capable of overcoming the aforesaid drawback of the prior art.
According to the present invention, a chuck assembly comprises: a housing that defines a cylindrical inner space therein and that is formed with a hydraulic fluid inlet adapted to be connected to a hydraulic fluid supply; a sleeve that is co-axially mounted in the inner space, that is secured to the housing, that defines a shaft-receiving space therein, and that is formed with an annular groove in fluid communication with the hydraulic fluid inlet; a hollow shaft that co-axially and rotatably extends through the shaft-receiving space, that defines a chuck-receiving space therein, that is rotatble relative to the sleeve about an axis, and that is formed with a first fluid passage in fluid communication with the annular groove; a chuck unit that is co-axially mounted in the chuck-receiving space, that includes a plurality of angularly displaced jaws, and that cooperates with the shaft to define a piston-receiving chamber therebetween; a piston that is co-axially mounted in the piston-receiving chamber, that subdivides the piston-receiving chamber into first and second compartments, that is displaceable in an axial direction relative to the axis, and that is connected to the chuck unit in such a manner that axial displacement of the piston results in radial displacement of the jaws, the first compartment being in fluid communication with the first fluid passage; and an annular elastic sealing member that is received in the annular groove, that is sleeved on the shaft, and that is formed with a second fluid passage in fluid communication with the first fluid passage so as to permit flow of hydraulic fluid from the hydraulic fluid supply to the first compartment.
In drawings which illustrate an embodiment of the invention,
The chuck assembly includes: a housing 100 that defines a cylindrical inner space 101 therein and that is formed with a hydraulic fluid inlet 102 (see
Referring to
Referring to
An urging member 44 is mounted in the second compartment 4022 in the piston-receiving chamber 402, and abuts against the piston 43 so as to accumulate a restoring force for restoring the piston 43 back to a normal position when the pressurized hydraulic fluid enters into the first compartment 4021 and moves the piston 43 to compress the urging member 44.
Referring to
Referring to
With the inclusion of the sealing member 30 in the chuck assembly of this invention, the aforesaid drawback as encountered in the prior art can be eliminated.
With the invention thus explained, it is apparent that various modifications and variations can be made without departing from the spirit of the present invention. It is therefore intended that the invention be limited only as recited in the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
3615100 | Banner | Oct 1971 | A |
4032162 | Flinchbaugh | Jun 1977 | A |
4094521 | Piotrowski | Jun 1978 | A |
4537410 | Hiestand | Aug 1985 | A |
5192086 | Bucks | Mar 1993 | A |
5302062 | Baba et al. | Apr 1994 | A |
6173971 | Shen | Jan 2001 | B1 |
6497417 | Wu | Dec 2002 | B2 |
20050040608 | Wu | Feb 2005 | A1 |
Number | Date | Country | |
---|---|---|---|
20050040609 A1 | Feb 2005 | US |