Multi-axis bevel and hypoid gear generating machine

In a computer numerically controlled machine for generating bevel and hypoid gears using a tool having stock removing surfaces projecting from a front face thereof for working both flanks of longitudinally curved tooth spaces in the gears, the machine of the type having:

• a support for mounting said tool for rotation about a tool axis;
• a support for mounting a work gear for rotation about a work axis;
• means for rotating said tool about its axis;
• means for rotating said work gear about its axis;
• means for relatively moving said work support and said tool support with respect to each other in three rectilinear directions;
• means for relatively pivoting said work support and said tool support with respect to each other about a pivot axis;
• and,
• a computer for substantially simultaneously controlling said rotation of the work gear together with said relative rectilinear movements between the tool and work gear for operatively engaging said tool with both flanks of said tooth spaces in the work gear and for imparting a predetermined relative rolling motion between said tool and said work gear as though the work gear were in mesh with a theoretical generating gear having an axis of rotation defined by said predetermined rolling motion and tooth flanks represented by said stock removing surfaces of the tool;
• the improvement wherein:
• said computer also provides for substantially simultaneously controlling said relative pivoting between the tool and work gear so as to relatively orient said tool axis inclined to said generating gear axis, whereby a range of generating gears can be defined by said predetermined rolling motion which would otherwise normally require a separate mechanical structure for this purpose.

In a computer numerically controlled machine for generating longitudinally curved tooth spaces in at least one member of a pair of bevel and hypoid gears using a tool having stock removing surfaces projecting from a front face thereof, the machine of a type having:

• a support for mounting said tool for rotation about a tool axis;
• a support for mounting one member of a mating work gear pair for rotation about a work axis;
• means for rotating said tool about said tool axis;
• means for rotating said one member about said work axis;
• means for relatively moving said work support and said tool support relative to each other in three rectilinear directions;
• means for relatively pivoting said work support and said tool support relative to each other about a pivot axis;
• and,
• a computer for substantially simultaneously controlling said rotation of the one member and said relative rectilinear movement between the work and tool supports for generating longitudinally curved tooth spaces in the one member;
• the improvement wherein:
• said computer provides for also substantially simultaneously controlling said relative pivoting between the work and tool supports so that said stock removing surfaces of the tool are oriented with respect to said one member so as to represent tooth surfaces of the other member of said work gear pair having an axis of rotation that is inclined to said tool axis.

In a machine for generating longitudinally curved tooth spaces in bevel and hypoid gears using a tool having stock removing surfaces, the machine of the type having:

• a machine base;
• a tool support mounted on said base;
• a tool spindle journaled in said tool support for mounting said tool, said tool spindle being journaled in said tool support in a fixed angular orientation with respect to said machine base;
• means for rotating said tool;
• a work support pivotally mounted on said base;
• a work spindle journaled in said work support for mounting a work gear;
• means for rotating said work gear;
• means for relatively moving said tool support and work support with respect to each other;
• and,
• means for effecting a predetermined relative rolling motion between said tool and said work gear as though said work gear were in mesh with a theoretical generating gear having an axis of rotation defined by said relative rolling motion and tooth surfaces represented by said stock removing surfaces of the tool;
• the improvement wherein:
• said rolling motion means provides for positioning said axis of rotation of the theoretical generating gear at one or more angular orientations which differ from the fixed angular orientation of said tool spindle, whereby conventional generating effects associated with an inclination of a tool spindle with respect to a theoretical generating gear axis are achieved with the tool spindle remaining in a fixed orientation.

In a computer controlled machine for generating tooth spaces in bevel and hypoid gears using a tool having stock removing surfaces, the machine of the type having:

• a support for mounting said tool for rotation about a tool axis;
• a support for mounting a work gear for rotation about a work axis;
• a drive motor for rotating said tool about said tool axis;
• a drive motor for rotating said work gear about said work axis;
• respective drive motors for relatively moving said work support and said tool support with respect to each other along three rectilinear axis;
• and,
• a drive motor for relatively pivoting said work support and said tool support with respect to each other about a pivot axis;
• and,
• encoders associated with each of said drive motors for providing feedback information concerning positions of the tool and work gear with respect to each of said axes;
• and,
• a computer for moving each of said drive motors to predetermined setup positions and for substantially simultaneously controlling said work gear drive motor and said respective drive motors for imparting a predetermined relative rolling motion between said tool and said work gear as though the work gear were in mesh with a theoretical generating gear having an axis of rotation defined by said predetermined rolling motion and tooth flanks represented by said stock removing surfaces of the tool;
• the improvement wherein:
• said computer includes means for determining incremental rotational positions of said theoretical generating gear and for performing calculations based on said incremental positions for controlling each of said drive motors involved with imparting said predetermined rolling motion.

In a machine for generating bevel and hypoid gears, using a tool having stock removing surfaces, including no more than six movable machine axes for setting initial positions of said tool and a work gear and for operatively engaging said tool with said work gear, the machine of a type having:

• an axis for rotating said work gear;
• an axis for rotating said tool;
• three axes for translating said tool and said work gear with respect to each other;
• no more than one axis for pivoting said tool and said work gear with respect to each other;
• means for imparting a predetermined relative rolling motion between said tool and said work gear about a theoretical axis of rotation defined by said motion;
• the improvement wherein:
• said motion means includes means for adjusting said rotation of the work gear to compensate for additional relative movements of said theoretical axis of rotation about said work axis so as to maintain said predetermined relative rolling motion.

In an apparatus for making bevel and hypoid gears having longitudinally curved tooth spaces in an enveloping process wherein tooth surfaces are defined in a work gear by the stock removing surfaces of a tool and relative motions of said tool with respect to said work gear, the apparatus of a type including:

• means for rotating said tool about a tool axis;
• means for rotating said work gear about a work axis;
• means for translating said tool axis and said work axis with respect to each other in three directions;
• means for pivoting said tool axis and work axis with
• respect to each other;
• and,
• means for substantially simultaneously controlling said rotation of the work gear together with said translation between the tool and work axes for moving said stock removing surfaces in a path of engagement with said tooth surfaces of the work gear angularly with respect to a plane of action between them;
• the improvement wherein:
• said controlling means provides for also substantially simultaneously controlling said pivoting between the tool and work axes thereby defining a theoretical axis of rotation between said tool axis and said work axis to which said tool axis is inclined and which varies in inclination with respect to said pivot axis, whereby said angularity of engagement between the tool and work gear may be further controlled.

Apparatus for making gears on a first gear-making machine having N moveable axes for positioning and relatively moving a tool member and a work gear member being formed characterized by:

• means for generating signal values for M moveable axes representative of positions and relative movements between said members as is required for forming a predetermined gear using a second gear making machine having certain of said M axes arranged in the same configuration as certain of said N axes of said first machine, said M axes being a larger number of axes than said N axes;
• means for transforming said signal values for said M axes into signal values for said N axes;
• said signal values for said certain of the M axes being different than said signal values for said certain of the N axes arranged in the same configuration;
• and
• means for controlling said first gear-making machine in response to said signal values for said N axes to form said predetermined gear from said work gear member.

In an apparatus for generating longitudinally curved tooth gears according to a continuous indexing process using a tool having stock removing surfaces, the apparatus of a type having:

• a base;
• a tool support mounted to said base and defining a tool axis about which a tool is rotatable, said tool axis having a fixed angular orientation with respect to said base;
• a work gear support mounted to said base defining a work axis about which a work gear is rotatable;
• no more than one pivot axis inclined at a predetermined inclination with respect to both said tool axis and said work axis and about which said work axis is pivotally mounted with respect to said base;
• means for rotating said tool;
• means for rotating said work gear;
• rectilinear motion means for producing three-dimensional rectilinear relative motion between said tool and work supports;
• and,
• motion control means for substantially simultaneously controlling said rotation of the work gear together with said rectilinear motion between the tool and work supports for imparting a predetermined relative rolling motion between the tool and work gear about a theoretical axis of rotation and for substantially simultaneously controlling relative rotations between said work gear and said tool about their respective axes in a predetermined timed relationship with each other;
• the improvement wherein:
• said motion control means includes means for adjusting said rotation of the work gear as a function of movement of said tool axis about said generating gear axis so as to maintain said predetermined timed relationship between the tool and work gear.

A method of forming longitudinally curved tooth spaces in bevel and hypoid gears using a tool having stock removing surfaces comprising the steps of:

• mounting said tool in a tool support;
• mounting a work gear in a work gear support;
• setting in rotation said tool about an axis which passes through said tool;
• setting in rotation said work gear about an axis which passes through said work gear;
• relatively moving said tool support with respect to said work support along three rectilinear axes for initially positioning said work and tool supports rectilinearly with respect to each other;
• relatively pivoting said work support angularly with respect to said tool support about no more than one pivot axis for initially positioning said work and tool supports angularly with respect to each other;
• and,
• substantially simultaneously controlling said rotation of the work gear, said rectilinear movement between the work and tool supports and said pivoting between the work and tool supports so as to operatively engage said tool with said work gear in a predetermined rolling motion between said tool and said work gear about a theoretical axis of rotation that is inclined to said tool axis.

A method of forming longitudinally curved tooth spaces in bevel and hypoid gears using a tool having stock removing surfaces comprising the steps of:

• mounting said tool in a fixed angular orientation with respect to a machine base;
• rotating said tool in engagement with a work gear;
• and
• relatively moving said tool with respect to said work gear along three rectilinear machine axes, pivoting said work gear relative to said tool and rotating said work gear on its axis so as to impart a predetermined relative rolling motion between said tool and said work gear as though the work gear were in mesh with a theoretical generating gear having tooth surfaces represented by said stock removing surfaces of the tool and an axis of rotation which is positioned at one or more angular orientations which differ from said fixed angular orientation of the tool.

A method for making bevel and hypoid gears having longitudinally curved teeth according to an enveloping process, wherein tooth surfaces are defined in a work gear by stock removing surfaces of a tool and relative motions of said tool with respect to said work gear, comprising the steps of:

• mounting said tool for rotation in a tool support;
• rotating said work gear to a starting position in a work support;
• moving said tool support and said work support along three rectilinear axes to said starting position;
• pivoting said tool support and work support with respect to each other to said starting position;
• and,
• substantially simultaneously controlling said rotation of the work gear, said rectilinear movement between the work and tool supports, and said pivoting between said work and tool supports for moving said stock removing surfaces of the tool in a path of engagement with said tooth surfaces of the work gear angularly with respect to a plane of action between them, thereby defining a theoretical axis of rotation between said tool axis and said work axis to which said tool axis is inclined and which varies in inclination with respect to said pivot axis.

A method for making gears on a first gear-making machine having N moveable axes for positioning and relatively moving a tool member and a work gear member being formed, said method characterized by the steps of:

• generating signal values for M moveable axes representative of positions and relative movements between said members as is required for forming a predetermined gear using a second gear-making machine having certain of said M axes arranged in the same configuration as certain of said N axes of said first machine, said M axes being a larger number of axes than said N axes;
• transforming said signal values for said M axes into signal values for said N axes;
• said signal values for said certain of the M axes being different than said signal values for said certain of the N axes arranged in the same configuration;
• and
• controlling said first gear-making machine in response to said signal values for said N axes to form said predetermined gear from said work gear member.

A method of generating longitudinally curved tooth spaces in bevel and hypoid gears with a computer controlled machine having a plurality of computer controlled axes for positioning and operatively engaging a tool with a work gear characterized by the steps of:

• machine determining initial setup positions of said computer controlled axes based on setup parameters of differently configured axes of a conventional bevel and hypoid generating machine of the type including a cradle rotatable about a cradle axis, a tool support having a tool axis adjustably mounted on said cradle for inclining said tool axis with respect to said cradle axis and a work support having a work axis;
• moving said computer controlled axes to said initial setup positions for initially positioning said tool and work gear with respect to each other;
• machine determining further operating positions of said computer controlled axes based on operating parameters which relate to relative movements of said differently configured axes of the conventional machine;
• moving said computer controlled axes to said further operating positions for operatively engaging said tool with said work gear, said tool and said work gear assuming positions in the computer controlled machine thereby which differ from those positions that would be effected by the differently configured axes in the conventional machine but said tool and said work gear remaining in the same relative positions with respect to each other as they would in the conventional machine;
• and,
• repeating said steps of machine determining further operating positions and moving said computer controlled axes to said further operating positions for completing the generating operation.

A computer processor for controlling a bevel and hypoid gear generating machine for generating longitudinally curved gears using a tool having stock removing surfaces projecting from a front face thereof, said computer processor comprising:

• means for controlling rotation of said tool about a tool axis;
• means for controlling rotation of a work gear about a work axis;
• means for controlling movement between said tool and said work gear along three rectilinear axes;
• means for controlling angular movement between said tool axis and said work axis about a pivot axis;
• means for substantially simultaneously controlling said rotation of the work gear, said rectilinear movements between the tool and work gear, and said angular movement between the tool and work axes for imparting a predetermined relative rolling motion between said tool and said work gear about a theoretical axis of rotation that is inclined to said tool axis and describes a relative movement of said tool along a path inclined to a line of action between the tool and work gear defined by a locus of points of contact between the tool and work gear.

A computer processor for controlling a bevel and hypoid gear generating machine having a plurality of computer controlled axes for positioning and operatively engaging a tool with a work gear, said computer processor characterized by:

• means for determining initial setup positions of said computer controlled axes based on setup parameters of differently configured axes of a conventional bevel and hypoid gear generating machine of the type including a cradle rotatable about a cradle axis, a tool support having a tool axis adjustably mounted on said cradle for inclining said tool axis with respect to said cradle axis and a work support having a work axis;
• and,
• means for determining further operating positions of said computer controlled axes based on operating parameters which relate to relative movements of said differently configured axes of the conventional machine;
• said further operating means providing for performing a coordinate transformation for relating operating positions which would be effected by said conventional machine axes to said further operating positions of the computer controlled axes.