US 12,215,771 B2 · Harmonic reducer with conjugate cycloidal profiles

Abstract

The present disclosure discloses a harmonic reducer with conjugate cycloidal profiles, including a circular spline, a flexspline, a wave generator and a flexible bearing. A profile of the circular spline and a profile of the flexspline are conjugate cycloidal profiles. The profile of the circular spline and the profile of the flexspline are formed by hypocycloids and epicycloids formed by two rolling circles around a pitch circle of the circular spline and a pitch circle of the flexspline under an engaging state respectively. A sum of radii of the first rolling circle and the second rolling circle is equal to a difference between radii of the pitch circle of the circular spline and the pitch circle of the flexspline under the engaging state. The wave generator is a biarc cam wave generator, a cam curve is an arc within an angle of contact in the long axis direction.

A harmonic reducer with conjugate cycloidal profiles, including a circular spline (1), a flexspline (2), a wave generator (3) and a flexible bearing (4);

the flexible bearing (4) is installed between the wave generator (3) and the flexspline (2);
Wherein, a profile of the circular spline (1) and a profile of the flexspline (2) under an engaging state are conjugate cycloidal profiles, which are formed by tooth addendum profiles and tooth dedendum profiles respectively;
the tooth addendum profile of the circular spline (1) is a hypocycloid formed by a first rolling circle pure rolling around a pitch circle of the circular spline (1), and the tooth dedendum profile of the circular spline (1) is an epicycloid formed by a second rolling circle pure rolling around the pitch circle of the circular spline (1);
the tooth dedendum profile of the flexspline (2) is a hypocycloid formed by the first rolling circle pure rolling around a pitch circle of the flexspline (2) under the engaging state, and the tooth addendum profile of the flexspline (2) is an epicycloid formed by the second rolling circle pure rolling around the pitch circle of the flexspline (2) under the engaging state;
a sum of radii of the first rolling circle and the second rolling circle is equal to a difference between radii of the pitch circle of the circular spline and the pitch circle of the flexspline under the engaging state, so as to achieve complete conjugation of the profile of the circular spline (1) and the profile of the flexspline (2), increase the number of paired teeth with conjugate engagement, and improve bearing capacity;
equations of the conjugate cycloidal profiles under respective coordinate systems are
{
x
circular
⁢
spline
⁢
tooth
⁢
addendum
=
R
⁢
sin
⁢
(
t
-
R
R
1
⁢
t
)
-
(
R
1
-
R
)
⁢
sin
⁢
(
R
R
1
⁢
t
)
y
circular
⁢
spline
⁢
tooth
⁢
addendum
=
R
⁢
cos
⁢
(
t
-
R
R
1
⁢
t
)
+
(
R
1
-
R
)
⁢
cos
⁢
(
R
R
1
⁢
t
)
{
x
flexspline
⁢
tooth
⁢
addendum
=
R
⁢
sin
⁢
(
t
-
R
R
2
⁢
t
)
+
(
R
-
R
2
)
⁢
sin
⁢
(
R
R
2
⁢
t
)
y
flexspline
⁢
tooth
⁢
addendum
=
R
⁢
cos
⁢
(
t
⁢
-
R
R
2
⁢
t
)
-
(
R
-
R
2
)
⁢
cos
⁢
(
R
R
2
⁢
t
)
{
x
circular
⁢
spline
⁢
tooth
⁢
dedendum
=
(
R
1
+
R
-
R
2
)
⁢
sin
⁢
(
R
2
-
R
R
1
⁢
t
)
+
(
R
2
-
R
)
⁢
sin
⁢
(
R
2
-
R
R
1
⁢
t
-
t
)
y
circular
⁢
spline
⁢
tooth
⁢
dedendum
=
(
R
1
+
R
-
R
2
)
⁢
cos
⁢
(
R
2
-
R
R
1
⁢
t
)
+
(
R
2
-
R
)
⁢
cos
⁢
(
R
2
-
R
R
1
⁢
t
-
t
)
{
x
flexspline
⁢
tooth
⁢
dedendum
=
(
R
2
+
R
-
R
1
)
⁢
sin
⁢
(
R
1
-
R
R
2
⁢
t
)
+
(
R
1
-
R
)
⁢
sin
⁢
(
R
1
-
R
R
2
⁢
t
-
t
)
y
flexspline
⁢
tooth
⁢
dedendum
=
(
R
2
+
R
-
R
1
)
⁢
cos
⁢
(
R
1
-
R
R
2
⁢
t
)
+
(
R
1
-
R
)
⁢
cos
⁢
(
R
1
-
R
R
2
⁢
t
-
t
)
in the formulae, parameters are defined based on a coordinate system O1-x1y1 of the circular spline and a coordinate system O2-x2y2 of the flexspline, which are established with O1, O2 as origins of coordinates, and connecting lines of O1 and the point P, O2 and the point P as an axis y1 and an axis y2, respectively;
wherein, R1 is the radius of the pitch circle of the circular spline, and R2 is the radius of the pitch circle of the flexspline under the engaging state;
the radius R of the rolling circles meets:
R=R1−r1=R2+r2;
and parameter t is a profile parameter, which corresponds to an angle at which the rolling circle rolls around the pitch circle;
and
the wave generator (3) is a biarc cam wave generator, and a cam curve of the biarc cam wave generator is an arc within an angle of contact in the long axis direction of the wave generator.

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Harmonic reducer with conjugate cycloidal profiles

Life of this patent

Harmonic reducer with conjugate cycloidal profiles

Life of this patent

Abstract

Claims4