Patents by Inventor Mohamed Mizanur Rahman

Mohamed Mizanur Rahman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6137650
    Abstract: A hydrodynamic fluid bearing useful in a bearing cartridge which cartridge may be incorporated into a spindle motor or the like, where the bearing includes a shaft, a conical bearing supported on the shaft, and journal bearings located at least on one side and typically both above and below the conical bearing. A sleeve is mounted for rotation relative to the shaft and defines, in cooperation with the shaft, the gaps necessary for both the conical hydrodynamic bearing and the axial, journal bearings. At an end of the shaft, capillary seals are defined between the sleeve and the shaft so that fluid does not escape from the hydrodynamic bearing. The shaft itself includes a central hole, with bores communicating with both the conical bearing and the journal bearings to maintain appropriate pressure balances.In a further desirable feature, in some embodiments the diameter of one end of the shaft can be made greater than the diameter of the other end of the shaft.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: October 24, 2000
    Assignee: Seagate Technology L.L.C.
    Inventors: Gunter Karl Heine, Mohamed Mizanur Rahman, Raquib Uddin Khan, Hans Leuthold
  • Patent number: 6130802
    Abstract: A method of creating an improved hydrodynamic fluid bearing is provided which is relatively insensitive to shock vibration changes in load and rotational speed. The hydrodynamic bearing motor in which the bearing is open at both the upper and lower ends, and in which the balance of fluid flow within the bearings is maintained. The assembly of the hydrodynamic bearing is more easily assembled, and the gaps are easily adjusted. In the design of the hydrodynamic bearing, the tolerances for assembly of the various components is minimized that is, the critical nature of many of the gaps is diminished.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: October 10, 2000
    Assignee: Seagate Technology, Inc.
    Inventors: Mohamed Mizanur Rahman, Gunter Karl Heine, Hans Leuthold, Raquib Uddin Khan
  • Patent number: 6118620
    Abstract: A hydrodynamic bearing system where the bearing includes a shaft and two independent bearings, comprising a top cone or bi-sphere and a bottom cone or bi-sphere separated by a segment of the shaft. The bearing includes a hub supported bearing element rotating around the shaft and the shaft supported top cone and bottom cone; complementary surfaces of said bearing element and said cone define a narrow gap between the bearing support element for the bearing fluid. Sealing plates or seal elements define a fluid gap with a radially extending face of the cone; a gap also exists between an interior surface portion of each cone and the shaft. These gaps are connected so that separate flow paths are established, one around the top cone or bi-sphere and one around the bottom cone or bi-sphere. By providing two independent bearings, the stator can be mounted to the shaft, facing magnets supported on the hub to form an in-hub motor.
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: September 12, 2000
    Assignee: Seagate Technology LLC
    Inventors: Alan Lyndon Grantz, Norbert Steven Parsoneault, Samnathan Murthy, Hans Leuthold, Mohamed Mizanur Rahman
  • Patent number: 6069767
    Abstract: The third dynamic bearing includes a fixed shaft and a sleeve rotating around and surrounding the shaft, and at least first and second thrust plates separated by a portion of the shaft. The shaft includes an axial hole to vent appropriate positions inside the bearing. The axial hole extends from one end of the shaft past at least one of the thrust plates. The axial hole is connected by a radial bore to the bearing gap at a location between the thrust plate closest to that one end of the shaft and the facing counterplate.Alternatively, the axial hole can extend beyond the farthest thrust plate from the one end of the shaft, and can be connected to the bearing gap by a second radial cross-bore. A meniscus forms in the bearing gap on either side of each vent opening, decoupling adjacent bearing sections of the hydrodynamic bearing.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: May 30, 2000
    Assignee: Seagate Technology, Inc.
    Inventors: Raquib Uddin Khan, Gunter Karl Heine, Hans Leuthold, Mohamed Mizanur Rahman
  • Patent number: 6069768
    Abstract: A method to create an improved hydrodynamic bearing which is relatively insensitive to changes in load and rotational speed is provided, wherein the hydrodynamic bearing is useful in a spindle motor for a disc drive or the like which is stiffer than known standard spindle motors so that the stability of the system and specifically of the actuator arm and transducer relative to the rotating disc is optimized. The hydrodynamic bearing can also be used as a bearing cartridge or as the cartridge that may be incorporated into a spindle motor or the like, where the bearing includes a shaft and at least two independent bearings each comprising a thrust plate supported on the shaft and a counter plate incorporated in a sleeve which is capable of relative rotation around the shaft.
    Type: Grant
    Filed: April 26, 1999
    Date of Patent: May 30, 2000
    Assignee: Seagate Technology, Inc.
    Inventors: Gunter Karl Heine, Raquib Uddin Khan, Mohamed Mizanur Rahman, Hans Leuthold
  • Patent number: 6005748
    Abstract: A method to create an improved hydrodynamic bearing which is relatively insensitive to changes in load and rotational speed is provided, wherein the hydrodynamic bearing is useful in a spindle motor for a disc drive or the like which is stiffer than known standard spindle motors so that the stability of the system and specifically of the actuator arm and transducer relative to the rotating disc is optimized. The hydrodynamic bearing can also be used as a bearing cartridge or as the cartridge that may be incorporated into a spindle motor or the like, where the bearing includes a shaft and at least two independent bearings each comprising a thrust plate supported on the shaft and a counter plate incorporated in a sleeve which is capable of relative rotation around the shaft.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: December 21, 1999
    Assignee: Seagate Technology, Inc.
    Inventors: Gunter Karl Heine, Raquib Uddin Khan, Mohamed Mizanur Rahman, Hans Leuthold
  • Patent number: 5997179
    Abstract: The hydrodynamic bearing gap from one end to the other of the shaft and sleeve combination is effectively separated into sections, with the fluid in each bearing section being contained within that section. The viscosity of the fluid in each bearing section can then be selected to optimize the characteristics of the entire hydrodynamic bearing. Typically, the sections of the bearing adjacent each open end of the bearing would be filled with a fluid with relatively high viscosity. The remaining sections, toward the center of bearing, would typically be filled with a lower viscosity fluid, liquid or gas so that the power consumption within the motor itself would be minimized.
    Type: Grant
    Filed: April 22, 1998
    Date of Patent: December 7, 1999
    Assignee: Seagate Technology, Inc.
    Inventors: Raquib Uddin Khan, Gunter Karl Heine, Mohamed Mizanur Rahman