US 12,110,947 B2Granted

Continuously variable transmission

AssigneeEltat S.R.L.

InventorsCarlo Chiaves, Paolo Chiaves

Life of this patent

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Abstract

A continuously variable transmission includes a first main shaft and a second main shaft and at least one auxiliary shaft, rotatable around a rotation axis and interposed between the first and second main shafts. The auxiliary shaft has two secondary roll surfaces. Each secondary roll surface is shaped as a solid of revolution and is placed in contact with a respective primary roll surface of the first and second main shafts. The primary and secondary roll surfaces are shaped so that straight lines tangential thereto in contact points between the auxiliary shaft and the first and second main shafts pass through two distinct intersection points between the axes of the first and second main shafts.

Claims13

Dependent claims

A continuously variable transmission comprising:

a first main shaft and a second main shaft, having respective rotation axes fixed and coplanar with respect to a reference plane, said first and second main shafts each forming a primary roll surface shaped as a solid of revolution of one or more generatrix curves;
at least one auxiliary shaft, rotatable around a respective rotation axis, said auxiliary shaft being interposed between said first and second main shafts and comprising two secondary roll surfaces, each secondary roll surface being shaped as a solid of revolution and placed in contact with a respective primary roll surface of the first and second main shafts, so as to transmit motion from one main shaft to the other main shaft, said auxiliary shaft being configured so that its rotation axis is movable only along the reference plane identified by the rotation axes of the first and second main shafts;
wherein the primary roll surfaces are shaped such that:
in said reference plane, a line tangent to the primary roll surface of the first main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the first main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft;
and
in said reference plane, a line tangent to the primary roll surface of the second main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the second main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
and
the intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft is distinct from the intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
so that the secondary roll surfaces of the auxiliary shaft roll without rubbing and prying motion on the respective primary roll surfaces of the first and second main shafts, in all operating conditions;
wherein each of the first and second main shafts is bound so as not to move in a direction parallel to its rotation axis such that it can only rotate about its rotation axis.

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A continuously variable transmission comprising:

a first main shaft and a second main shaft, having respective rotation axes fixed and coplanar with respect to a reference plane, the rotation axis of the first main shaft intersecting in one point the rotation axis of the second main shaft, said first and second main shafts each comprising a primary roll surface shaped as a solid of revolution;
at least one auxiliary shaft, rotatable around a respective rotation axis, said auxiliary shaft being interposed between said first and second main shafts and comprising two secondary roll surfaces, each secondary roll surface being shaped as a solid of revolution and placed in contact with a respective primary roll surface of the first and second main shafts, so as to transmit motion from one main shaft to the other main shaft, said auxiliary shaft being configured so that its rotation axis is movable only along the reference plane identified by the rotation axes of the first and second main shafts;
wherein the primary roll surfaces are shaped such that:
in said reference plane, a line tangent to the primary roll surface of the first main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the first main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft;
and
in said reference plane, a line tangent to the primary roll surface of the second main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the second main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
and
the intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft is distinct from the intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
so that the secondary roll surfaces of the auxiliary shaft roll without rubbing and prying motion on the respective primary roll surfaces of the first and second main shafts, in all operating conditions.

6 more elements

A continuously variable transmission comprising:

a first main shaft and a second main shaft, having respective rotation axes fixed and coplanar with respect to a reference plane, said first and second main shafts each comprising a primary roll surface shaped as a solid of revolution;
at least one auxiliary shaft, rotatable around a respective rotation axis, said auxiliary shaft being interposed between said first and second main shafts and comprising two secondary roll surfaces, each secondary roll surface being shaped as a solid of revolution and placed in contact with a respective primary roll surface of the first and second main shafts, so as to transmit motion from one main shaft to the other main shaft, said auxiliary shaft being configured so that its rotation axis is movable only along the reference plane identified by the rotation axes of the first and second main shafts, said auxiliary shaft comprising two secondary shafts connected to each other by an engagement member adapted to constrain said two secondary shafts to maintain a constant ratio between respective rotational speeds;
wherein the primary roll surfaces are shaped such that:
in said reference plane, a line tangent to the primary roll surface of the first main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the first main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft;
and
in said reference plane, a line tangent to the primary roll surface of the second main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the second main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
and
the intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft is distinct from the intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
so that the secondary roll surfaces of the auxiliary shaft roll without rubbing and prying motion on the respective primary roll surfaces of the first and second main shafts, in all operating conditions.

6 more elements

A continuously variable transmission comprising:

a first main shaft and a second main shaft, having respective rotation axes fixed and coplanar with respect to a reference plane, said first and second main shafts each forming a primary roll surface shaped as a solid of revolution of one or more generatrix curves;
at least one auxiliary shaft, rotatable around a respective rotation axis, said auxiliary shaft being interposed between said first and second main shafts and comprising two secondary roll surfaces, each secondary roll surface being shaped as a solid of revolution and placed in contact with a respective primary roll surface of the first and second main shafts, so as to transmit motion from one main shaft to the other main shaft, said auxiliary shaft being configured so that its rotation axis is movable only along the reference plane identified by the rotation axes of the first and second main shafts;
wherein the primary roll surfaces are shaped such that:
in said reference plane, a line tangent to the primary roll surface of the first main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the first main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft;
and
in said reference plane, a line tangent to the primary roll surface of the second main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the second main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
and
the intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft is distinct from the intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
so that the secondary roll surfaces of the auxiliary shaft roll without rubbing and prying motion on the respective primary roll surfaces of the first and second main shafts, in all operating conditions;
wherein each of the first and second main shafts is bound so as not to move in a direction parallel to its rotation axis such that it can only rotate about its rotation axis, in such a way that the respective primary roll surfaces are bound so as not to move in a direction parallel to the rotation axes of their main shafts, such that they can only rotate about the rotation axes thereof.

7 more elements

Dependencies are inferred from the claim text.

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Abstract

A continuously variable transmission comprising:

a first main shaft and a second main shaft, having respective rotation axes fixed and coplanar with respect to a reference plane, said first and second main shafts each forming a primary roll surface shaped as a solid of revolution of one or more generatrix curves;
at least one auxiliary shaft, rotatable around a respective rotation axis, said auxiliary shaft being interposed between said first and second main shafts and comprising two secondary roll surfaces, each secondary roll surface being shaped as a solid of revolution and placed in contact with a respective primary roll surface of the first and second main shafts, so as to transmit motion from one main shaft to the other main shaft, said auxiliary shaft being configured so that its rotation axis is movable only along the reference plane identified by the rotation axes of the first and second main shafts;
wherein the primary roll surfaces are shaped such that:
in said reference plane, a line tangent to the primary roll surface of the first main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the first main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft;
and
in said reference plane, a line tangent to the primary roll surface of the second main shaft and to the respective secondary roll surface of the auxiliary shaft in a contact point between said primary roll surface of the second main shaft and the respective secondary roll surface of the auxiliary shaft passes through an intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
and
the intersection point between the rotation axis of said first main shaft and the rotation axis of said auxiliary shaft is distinct from the intersection point between the rotation axis of said second main shaft and the rotation axis of said auxiliary shaft;
so that the secondary roll surfaces of the auxiliary shaft roll without rubbing and prying motion on the respective primary roll surfaces of the first and second main shafts, in all operating conditions;
wherein each of the first and second main shafts is bound so as not to move in a direction parallel to its rotation axis such that it can only rotate about its rotation axis.

7 more elements