Patents by Inventor Naomi Shirasawa

Naomi Shirasawa 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: 8875598
    Abstract: A unit type wave gear device (1) has a unit housing (2), one end of which is defined by a two-stage cross roller bearing (7). The two-stage cross roller bearing (7) has: an inner cross roller bearing formed by an inner ring (13), an intermediate ring (12), and inner rollers (17) inserted into an inner track (16); and has an outer cross roller bearing formed by an outer ring (11), the intermediate ring (12), and outer rollers (15) inserted into an outer track (14). A flexible externally-toothed gear (22) affixed to the intermediate ring (12) is rotatably supported by the unit housing (2) via the outer cross roller bearing. An input shaft (4) affixed to the inner ring (13) and a wave generator (23) affixed to the input shaft (4) are rotatably supported by the intermediate ring (12) via the inner cross roller bearing. A unit type wave gear device can be realized in which the number of components are reduced and a large moment load is applied.
    Type: Grant
    Filed: May 16, 2011
    Date of Patent: November 4, 2014
    Assignee: Harmonic Drive Systems, Inc.
    Inventors: Masashi Horiuchi, Akihiro Yokoyama, Naomi Shirasawa
  • Publication number: 20140047938
    Abstract: A unit type wave gear device (1) has a unit housing (2), one end of which is defined by a two-stage cross roller bearing (7). The two-stage cross roller bearing (7) has: an inner cross roller bearing formed by an inner ring (13), an intermediate ring (12), and inner rollers (17) inserted into an inner track (16); and has an outer cross roller bearing formed by an outer ring (11), the intermediate ring (12), and outer rollers (15) inserted into an outer track (14). A flexible externally-toothed gear (22) affixed to the intermediate ring (12) is rotatably supported by the unit housing (2) via the outer cross roller bearing. An input shaft (4) affixed to the inner ring (13) and a wave generator (23) affixed to the input shaft (4) are rotatably supported by the intermediate ring (12) via the inner cross roller bearing. A unit type wave gear device can be realized in which the number of components are reduced and a large moment load is applied.
    Type: Application
    Filed: May 16, 2011
    Publication date: February 20, 2014
    Applicant: HARMONIC DRIVE SYSTEMS, INC.
    Inventors: Masashi Horiuchi, Akihiro Yokoyama, Naomi Shirasawa
  • Patent number: 7293632
    Abstract: In a brake-equipped retracting mechanism, rotational force of a motor is used to open a liquid crystal display device from a retracted position to an open position, a power spring is wound up in conjunction with this opening operation, and elastic restoring force thereof is used to return the liquid crystal display device from the open position to the retracted position. A rope for developing a greater or smaller tensile force in conjunction with opening and closing of the liquid crystal display device is wound around a slip clutch linked to a reducer input shaft, whereby braking force for preventing the liquid crystal display device from an abrupt return is applied to the reducer input shaft. The braking force gradually decreases as the liquid crystal display device returns to the retracted position, and the liquid crystal display device can therefore be returned at a substantially constant speed.
    Type: Grant
    Filed: September 8, 2005
    Date of Patent: November 13, 2007
    Assignee: Harmonic AD, Inc.
    Inventors: Norio Shirokoshi, Naomi Shirasawa
  • Publication number: 20060060439
    Abstract: In a brake-equipped retracting mechanism, rotational force of a motor is used to open a liquid crystal display device from a retracted position to an open position, a power spring is wound up in conjunction with this opening operation, and elastic restoring force thereof is used to return the liquid crystal display device from the open position to the retracted position. A rope for developing a greater or smaller tensile force in conjunction with opening and closing of the liquid crystal display device is wound around a slip clutch linked to a reducer input shaft, whereby braking force for preventing the liquid crystal display device from an abrupt return is applied to the reducer input shaft. The braking force gradually decreases as the liquid crystal display device returns to the retracted position, and the liquid crystal display device can therefore be returned at a substantially constant speed.
    Type: Application
    Filed: September 8, 2005
    Publication date: March 23, 2006
    Inventors: Norio Shirokoshi, Naomi Shirasawa
  • Patent number: 6948855
    Abstract: A two-stage cross roller bearing (1) includes a first cross roller bearing (10) and a second cross roller bearing (20) that are disposed concentrically along a plane that is perpendicular to the bearing axis 1a. The inner ring of the first cross roller bearing (10) and the outer ring of the second cross roller bearing (20) are formed of a single ring-shaped member (14), with an inner ring-side raceway groove (13) of the first cross roller bearing being formed on the circular outer circumferential surface of the ring-shaped member and an outer ring-side raceway groove (21) of the second cross roller bearing being formed on the circular inner circumferential surface of the ring-shaped member. A small, compact, and flat multistage cross roller bearing is realized.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: September 27, 2005
    Assignee: Harmonic Drive Systems, Inc.
    Inventor: Naomi Shirasawa
  • Publication number: 20050160855
    Abstract: In a linear movement/rotation mechanism, inside a tube-like housing, a ball screw/ball spline mechanism and a hollow planetary reduction gear are coaxially disposed, a drive shaft extends therethrough, and a ball screw nut, a ball spline nut, a hollow planetary reduction gear, and a driven pulley are disposed in that order along a center axis of the drive shaft. A rotational force inputted to the driven pulley is inputted to a hollow rotational shaft of the hollow planetary reduction gear, and a reduced rotation output is outputted from a rear stage internal gear. The reduced rotation output is transmitted to the ball spline nut that is connected and fixed to the rear stage internal gear. When the rotation of the ball screw nut is restricted, a feeding operation of the drive shaft is realized.
    Type: Application
    Filed: December 29, 2004
    Publication date: July 28, 2005
    Inventors: Yoshinori Aida, Naomi Shirasawa, Toshiaki Misawa
  • Patent number: 6866608
    Abstract: A planetary gear device includes a first, a second, and a third ring-shaped member that are concentrically arranged in that order from the inside. A sun gear is coaxially fixed to an end surface of the first ring-shaped member, planet shafts of planet gears are supported on an end surface of the ring-shaped member, and an internal gear is coaxially fixed to an end surface of the third ring-shaped member. A first cross roller bearing is formed between the first and second ring-shaped members and a second cross roller bearing is formed between the second and third ring-shaped members. Each member is arranged concentrically on a plane that is perpendicular to the device axis, so that a planetary gear device that is extremely slim in the device axial direction can be realized. Since the respective gear parts can be accessed from both sides in the device axial direction, the input and output can be laid out with great freedom.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: March 15, 2005
    Assignee: Harmonic Drive Systems, Inc.
    Inventor: Naomi Shirasawa
  • Publication number: 20040081379
    Abstract: A two-stage cross roller bearing (1) includes a first cross roller bearing (10) and a second cross roller bearing (20) that are disposed concentrically along a plane that is perpendicular to the bearing axis 1a. The inner ring of the first cross roller bearing (10) and the outer ring of the second cross roller bearing (20) are formed of a single ring-shaped member (14), with an inner ring-side raceway groove (13) of the first cross roller bearing being formed on the circular outer circumferential surface of the ring-shaped member and an outer ring-side raceway groove (21) of the second cross roller bearing being formed on the circular inner circumferential surface of the ring-shaped member. A small, compact, and flat multistage cross roller bearing is realized.
    Type: Application
    Filed: June 23, 2003
    Publication date: April 29, 2004
    Inventor: Naomi Shirasawa
  • Publication number: 20040048715
    Abstract: A planetary gear device (1) includes a first, a second, and a third ring-shaped member (10, 20, 30) that are concentrically arranged in that order from the inside. A sun gear (4) is coaxially fixed to an end surface of the first ring-shaped member (10), planet shafts (61 to 64) of planet gears (6-1 to 6-4) are supported on an end surface of the ring-shaped member (20), and an internal gear (2) is coaxially fixed to an end surface of the third ring-shaped member (30). A first cross roller bearing (40) is formed between the first and second ring-shaped members (10, 20) and a second cross roller bearing (50) is formed between the second and third ring-shaped members (20, 30). Each member is arranged concentrically on a plane that is perpendicular to the device axis (1a), so that an planetary gear device that is extremely slim in the device axial direction can be realized.
    Type: Application
    Filed: July 23, 2003
    Publication date: March 11, 2004
    Inventor: Naomi Shirasawa
  • Patent number: 6250179
    Abstract: A silk hat flexible engagement gear device (1) has first and second end plates (2, 3) and an input shaft (4) is rotatably supported, with their ends supported, between the tow end plates. An annular body (61) of a silk hat flexible external gear (6) is disposed on the outer circumference of the input shaft (4). A cross roller bearing (8) and a rigid internal gear (5) which also function as a device housing are arranged on the outer circumference. An cylindrical boss (64) of the flexible external gear is held between the outer race (81) of the cross roller bearing and the second end plate (3) and these three members are coupled with one another by means of second fixing bolts (11). An additional member which is used as a device housing is not necessary. The members are temporarily fixed and fastened and, further, attached to a housing on the motor side or on the load side by the fixing bolts (9, 11). Therefore, the number of components of the device can be reduced, whereby making the device small and compact.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: June 26, 2001
    Assignee: Harmonic Drive Systems, Inc.
    Inventor: Naomi Shirasawa
  • Patent number: 6182532
    Abstract: A cup-type wave gear device 1 comprises a cup-shaped flexible external gear 4 which has a boss 43 formed at its outer circumferential surface with an external thread 43b. An output shaft 6 is formed on Its end surface with an annular recess whose inner circumferential surface is formed with an internal thread 61. The external thread 43b of the boss 43 is screwed into the internal thread 61 of the output shaft 6. Further, driving pins 8 are used to fasten the boss 43 to the output shaft 6. Whereby, the flexible external gear 4 is fixedly connected to the output shaft 6 The fastening torque between the boss and the output shaft can be increased in comparison with the conventional case where fastening bolts are used to connect these parts.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: February 6, 2001
    Assignee: Harmonic Drive Systems, Inc.
    Inventor: Naomi Shirasawa
  • Patent number: 5906142
    Abstract: A wave gear drive (1) has first and second end plates (2) and (3) arranged to rotate relative with each other by means of a cross roller bearing (4) positioned between the plates (2, 3). An inner race (41) of the cross roller bearing (4) is formed integrally on a circumferential Inner surface with an internal gear (11). The inner race (41) is directly fastened to the first end plate (2), while an outer race (44) of the cross roller bearing (4) is fastened to the second end plate in a manner such that a circular boss (17) of a flexible external gear is held between the outer race (44) and the second end plate (3). The internal teeth (11) are positioned approximately at a radially inner side of a raceway (47) of the cross roller bearing (4). Thus, the wave gear drive (1) is small and compact, and the rigidity is increased.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: May 25, 1999
    Assignee: Harmonic Drive Systems, Inc.
    Inventor: Naomi Shirasawa
  • Patent number: 5850765
    Abstract: A flat wave gear drive (1) which has an input shaft (4) supported rotatably at both ends portions thereof between first and second end plates (2, 3). A wave gear mechanism is incorporated between these end plates (2,3), and a cross roller bearing (8) is provided on an outer circumferential side of the wave gear mechanism. The wave gear mechanism comprises a rigid internal gear (5), a silk-hat-shaped flexible external gear (6) provided on the inner side of the internal gear, and an wave generator (7) provided on the inner side of the external gear (6). An annular boss (64) of the flexible external gear is held between an outer ring (81) of the cross roller bearing (8) and the second end plate (3), whereby these three members are fastened to one another. The rigid internal gear (5) is held between an inner ring (82) of the cross roller bearing (8) and the first end plate (2), whereby these three members are fastened to one another. The input shaft (4) may comprise a hollow shaft.
    Type: Grant
    Filed: February 26, 1997
    Date of Patent: December 22, 1998
    Assignee: Harmonic Drive Systems, Inc.
    Inventor: Naomi Shirasawa
  • Patent number: 5775178
    Abstract: A wave gear device has a circular spline, a flexspline arranged within the circular spline, and a wave generator disposed within the flexspline for deflecting the flexspline in radial direction for partially engaging external tooth formed on the flexspline with internal gear teeth formed on the circular spline and shifting an engaging position in circumferential direction to cause relative rotation depending upon difference in number of teeth of the internal gear teeth and the external gear teeth between the circular spline and the flexspline. The circular spline has an annular rigid teeth portion formed with the internal gear teeth along the inner periphery thereof, a fastening portion to be rigidly secured on one of a device housing and a supporting member rotatably supported in the device housing, and a connecting portion connecting the rigid teeth portion and the fastening portion.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: July 7, 1998
    Assignee: Harmonic Drive Systems, Inc.
    Inventors: Hideo Asawa, Naomi Shirasawa
  • Patent number: 5715732
    Abstract: The silk-hat-shaped flexible external gear (13) of a silk-hat flexible meshing gear device (11) comprises a body (22), a diaphragm (23) and a boss (25). Between the main portion of the body (22) and a curved portion (222) is formed a thinned portion (221) whose thickness is about 80% that of the main portion. The thickness of the diaphragm (23) is defined to be largest at the inner edge (point A), smallest at the middle portion (point B) and slightly smaller than the largest thickness at the outer edge (point C). To make the change in thickness smooth throughout, the contour is defined by use of a group of curved lines (223, 224). Providing the thinned portion (221). and defining the thickness of the diaphragm (23) in the foregoing manner relieves stress concentration at the inner and outer edges and smooths the stress distribution. As a result, the axial length and the outer diameter can be reduced to realize a compact silk-hat flexible meshing gear device.
    Type: Grant
    Filed: October 3, 1996
    Date of Patent: February 10, 1998
    Assignee: Harmonic Drive Systems, Inc.
    Inventors: Noboru Takizawa, Naomi Shirasawa