Tripod constant-velocity joint
A tripod constant-velocity joint includes: an outer joint member having a cavity elongated in a longitudinal direction and three roller tracks; an inner joint member having a center body and three journals outwardly radially protruded from the center body; and three roller assemblies respectively coupled to the journal in a state of being respectively disposed in the roller tracks. The respective roller assembly comprises: an inner race which is connected to the journal and is provided with a first inner ball groove and a second inner ball groove on both lateral sides thereof; a first ball array and a second ball array respectively having a plurality of balls which are respectively disposed in the first inner ball groove and in the second inner ball groove; and a ball cage which restricts movements of the first ball array and the second ball array in a longitudinal direction thereof.
1. A tripod constant-velocity joint comprising:
an outer joint member having a cavity elongated in a longitudinal direction and three roller tracks;
an inner joint member having a center body and three journals outwardly radially protruded from the center body; and
three roller assemblies respectively coupled to the journal in a state of being respectively disposed in the roller tracks,
wherein the respective roller assembly comprises:
an inner race which is connected to the journal and is provided with a first inner ball groove and a second inner ball groove on both lateral sides thereof;
a first ball array and a second ball array respectively having a plurality of balls which are respectively disposed in the first inner ball groove and in the second inner ball groove; and
a ball cage which restricts movements of the first ball array and the second ball array in a longitudinal direction thereof,
wherein the first ball array is disposed in a first ball track which is formed by the first inner ball groove and a first outer ball groove formed in a corresponding lateral side surface of one of the three roller tracks, and the second ball array is disposed in a second ball track which is formed by the second inner ball groove and a second outer ball groove formed in a corresponding lateral side surface of one of the three roller tracks,
wherein the first ball track is configured such that a sectional area thereof becomes larger in a direction toward an open side of the outer joint member, and the second ball track is configured such that a sectional area thereof becomes smaller in a direction toward the open side of the outer joint member, and
wherein diameters of the plurality of the balls composing the first ball array become larger in a direction toward the open side of the outer joint member, and diameters of the plurality of the balls composing the second ball array become smaller in a direction toward the open side of the outer joint member.
2. The tripod constant-velocity joint of claim 1 , wherein the first inner ball groove is formed such that a bottom surface thereof becomes deeper in a direction toward the open side of the outer joint member and the second inner ball groove is formed such that a bottom surface thereof becomes shallower in a direction toward the open side of the outer joint member.
3. A tripod constant-velocity joint comprising:
an outer joint member having a cavity elongated in a longitudinal direction and three roller tracks;
an inner joint member having a center body and three journals outwardly radially protruded from the center body; and
three roller assemblies respectively coupled to the journal in a state of being respectively disposed in the roller tracks,
wherein the respective roller assembly comprises:
an inner race which is connected to the journal and is provided with a first inner ball groove and a second inner ball groove on both lateral sides thereof;
a first ball array and a second ball array respectively having a plurality of balls which are respectively disposed in the first inner ball groove and in the second inner ball groove; and
a ball cage which restricts movements of the first ball array and the second ball array in a longitudinal direction thereof,
wherein the first ball array is disposed in a first ball track which is formed by the first inner ball groove and a first outer ball groove formed in a corresponding lateral side surface of one of the three roller tracks, and the second ball array is disposed in a second ball track which is formed by the second inner ball groove and a second outer ball groove formed in a corresponding lateral side surface of one of the three roller tracks,
wherein the first ball track is configured such that a sectional area thereof becomes larger in a direction toward an open side of the outer joint member and the second ball track is configured such that a sectional area thereof becomes smaller in a direction toward the open side of the outer joint member, and
wherein the first outer ball groove is formed such that a bottom surface thereof becomes deeper in a direction toward the open side of the outer joint member and the second outer ball groove is formed such that a bottom surface thereof becomes shallower in a direction toward the open side of the outer joint member.
4. A tripod constant-velocity joint comprising:
an outer joint member having a cavity elongated in a longitudinal direction and three roller tracks;
an inner joint member having a center body and three journals outwardly radially protruded from the center body; and
three roller assemblies respectively coupled to the journal in a state of being respectively disposed in the roller tracks,
wherein the respective roller assembly comprises:
an inner race which is connected to the journal and is provided with a first inner ball groove and a second inner ball groove on both lateral sides thereof;
a first ball array and a second ball array respectively having a plurality of balls which are respectively disposed in the first inner ball groove and in the second inner ball groove; and
a ball cage which restricts movements of the first ball array and the second ball array in a longitudinal direction thereof,
wherein the first ball array is disposed in a first ball track which is formed by the first inner ball groove and a first outer ball groove formed in a corresponding lateral side surface of one of the three roller tracks, and the second ball array is disposed in a second ball track which is formed by the second inner ball groove and a second outer ball groove formed in a corresponding lateral side surface of one of the three roller tracks,
wherein the first ball track is configured such that a sectional area thereof becomes larger in a direction toward an open side of the outer joint member and the second ball track is configured such that a sectional area thereof becomes smaller in a direction toward the open side of the outer joint member, and
wherein the first ball track has a shape of a truncated cone being widened in a direction toward the open side of the outer joint member and the second ball track has a shape of a truncated cone being narrowed in a direction toward the open side of the outer joint member.
5. The tripod constant-velocity joint of claim 4 , wherein center lines of the first ball track and the second ball track are parallel respectively with a longitudinal direction of the outer joint member.
6. A tripod constant-velocity joint comprising:
an outer joint member having a cavity elongated in a longitudinal direction and three roller tracks;
an inner joint member having a center body and three journals outwardly radially protruded from the center body; and
three roller assemblies respectively coupled to the journal in a state of being respectively disposed in the roller tracks,
wherein the respective roller assembly comprises:
an inner race which is connected to the journal and is provided with a first inner ball groove and a second inner ball groove on both lateral sides thereof;
a first ball array having a plurality of balls which are movably disposed in a first ball track formed by a first inner ball groove and a first outer ball groove which are correspondingly formed on both lateral sides of the roller tracks;
a second ball array having a plurality of balls which are movably disposed in a second ball track formed by a second inner ball groove and a second outer ball groove which are correspondingly formed on both lateral sides of the roller tracks; and
a ball cage which restricts movements of the first ball array and the second ball array in a longitudinal direction thereof,
wherein the first ball track is formed such that a sectional area thereof becomes larger in a direction toward an open side of the outer joint member, and the second ball track is formed such that a sectional area thereof becomes smaller in a direction toward an open side of the outer joint member, and
wherein diameters of the plurality of the ball composing the first ball array become larger in a direction toward the open side of the outer joint member, and diameters of the plurality of the ball composing the second ball array become smaller in a direction toward the open side of the outer joint member.
7. A tripod constant-velocity joint comprising:
an outer joint member having a cavity elongated in a longitudinal direction and three roller tracks;
an inner joint member having a center body and three journals outwardly radially protruded from the center body; and
three roller assemblies respectively coupled to the journal in a state of being respectively disposed in the roller tracks,
wherein the respective roller assembly comprises:
an inner race which is connected to the journal and is provided with a first inner ball groove and a second inner ball groove on both lateral sides thereof;
a first ball array having a plurality of balls which are movably disposed in a first ball track formed by a first inner ball groove and a first outer ball groove which are correspondingly formed on both lateral of the roller track;
a second ball array having a plurality of balls which are movably disposed in a second ball track formed by a second inner ball groove and a second outer ball groove which are correspondingly formed on both lateral sides of the roller track; and
a ball cage which restricts movements of the first ball array and the second ball array in a longitudinal direction thereof,
wherein the first ball track is formed such that a sectional area thereof becomes larger in a direction toward an open side of the outer joint member, and the second ball track is formed such that a sectional area thereof becomes smaller in a direction toward an open side of the outer joint member, and
wherein the first ball track has a shape of a truncated cone being widened in a direction toward the open side of the outer joint member and the second ball track has a shape of a truncated cone being narrowed in a direction toward the open side of the outer joint member.
8. The tripod constant-velocity joint of claim 7 , wherein center lines of the first ball track and the second ball track are parallel respectively with a longitudinal direction of the outer joint member.