Abstract: A valve timing adjustment device includes: a housing member; a vane rotor that includes vanes and is securely coupled to a driven shaft and is rotatable relative to the housing member when the vane rotor receives a pressure of hydraulic oil introduced into hydraulic chambers; a fixing member that fixes the vane rotor to the driven shaft; and a bearing section that rotatably supports the housing member. The housing member includes a winding section that is formed at an outer peripheral surface of the housing member. A transmission member is wound around the winding section. The bearing section and the winding section at least partially overlap with each other when viewed in a direction perpendicular to an axial direction.

Abstract: A check valve is made of a resilient body wound in a ring form and is located in an annular flow passage. A displacement limiter includes: a limiter main body that is located on an outer side of the check valve and is configured to limit displacement of the check valve in a diameter increasing direction of the check valve; and a limiter flow passage that communicates between one side and the other side of the limiter main body in an axial direction to enable hydraulic oil to flow between the one side and the other side of the limiter main body through the limiter flow passage.

Abstract: A drain port of a hydraulic oil controller is connected to an oil discharge portion. Each of partitions partitions between a corresponding one of drain oil passages and a corresponding one of a retard supply oil passage and an advance supply oil passage. Each of the drain oil passages connects between the oil discharge portion and a corresponding one of a retard chamber and an advance chamber. A recycle oil passage connects between: a portion of each drain oil passage located between the corresponding partition and the drain port; and the retard supply oil passage or the advance supply oil passage. A drain flow restrictor is formed in the portion of each drain oil passage located between the corresponding partition and the drain port. A passage cross-sectional area of the drain flow restrictor is smaller than a smallest passage cross-sectional area of the recycle oil passage and is constant.

Abstract: An annular groove has: a side peripheral surface that is shaped in a ring form and is formed such that the side peripheral surface inwardly extends from a bottom surface of the annular groove in a radial direction of a tubular member and is joined to an inner peripheral wall of the tubular member; and a specific shape surface that is formed along at least a part of the side peripheral surface between a bottom surface side end part and an inner peripheral wall side end part of the side peripheral surface such that a diameter of the specific shape surface is progressively reduced in an axial direction of the tubular member from one axial side, at which the bottom surface is placed, toward another axial side, at which the inner peripheral wall is placed.

Abstract: A supply passage extends through an inner sleeve in a radial direction and conducts hydraulic oil received from a hydraulic oil supply source. An axial passage is located between an outer sleeve and the inner sleeve and extends in an axial direction. The supply passage opens to one end portion of the axial passage while another end portion of the axial passage is configured to connect with a valve timing adjustment device. A supply check valve is installed in the axial passage and is located on a radial side of the supply passage where a radially outer side of the inner sleeve is placed. The supply check valve enables a flow of the hydraulic oil from the supply passage toward the axial passage and limits a flow of the hydraulic oil from the axial passage toward the supply passage.

Abstract: A valve timing adjustment device includes: a housing member; a vane rotor that includes vanes and is securely coupled to a driven shaft and is rotatable relative to the housing member when the vane rotor receives a pressure of hydraulic oil introduced into hydraulic chambers; a fixing member that fixes the vane rotor to the driven shaft; and a bearing section that rotatably supports the housing member. The housing member includes a winding section that is formed at an outer peripheral surface of the housing member. A transmission member is wound around the winding section. The bearing section and the winding section at least partially overlap with each other when viewed in a direction perpendicular to an axial direction.

Abstract: A drain port of a hydraulic oil controller is connected to an oil discharge portion. Each of partitions partitions between a corresponding one of drain oil passages and a corresponding one of a retard supply oil passage and an advance supply oil passage. Each of the drain oil passages connects between the oil discharge portion and a corresponding one of a retard chamber and an advance chamber. A recycle oil passage connects between: a portion of each drain oil passage located between the corresponding partition and the drain port; and the retard supply oil passage or the advance supply oil passage. A drain flow restrictor is formed in the portion of each drain oil passage located between the corresponding partition and the drain port. A passage cross-sectional area of the drain flow restrictor is smaller than a smallest passage cross-sectional area of the recycle oil passage and is constant.

Abstract: A check valve is made of a resilient body wound in a ring form and is located in an annular flow passage. A displacement limiter includes: a limiter main body that is located on an outer side of the check valve and is configured to limit displacement of the check valve in a diameter increasing direction of the check valve; and a limiter flow passage that communicates between one side and the other side of the limiter main body in an axial direction to enable hydraulic oil to flow between the one side and the other side of the limiter main body through the limiter flow passage.

Abstract: A retard supply check valve is installed in a retard supply passage and is located on a side of a hydraulic oil controller where a hydraulic oil supply source is placed. The retard supply check valve enables only a flow of hydraulic oil from the hydraulic oil supply source toward a retard chamber. An advance supply check valve is installed in an advance supply passage and is located on the side of the hydraulic oil controller where the hydraulic oil supply source is placed. The advance supply check valve enables only a flow of the hydraulic oil from the hydraulic oil supply source toward an advance chamber.

Abstract: A sleeve includes: a supply port communicated with a hydraulic oil supply source; a primary control port communicated with a retard chamber, a secondary control port communicated with an advance chamber; and a drain port communicated with an outside of a valve timing adjustment device. A spool includes: a pressure accumulation space formed at an inside of the spool; a supply passage configured to connect between the pressure accumulation space and the supply port; a primary control passage configured to connect between the pressure accumulation space and the primary control port; a secondary control passage configured to connect between the pressure accumulation space and the secondary control port; and a recycle passage configured to connect between the primary control port or the secondary control port and the pressure accumulation space. The recycle passage and the drain port are connected with each other at the inside of the sleeve.

Abstract: An annular groove has: a side peripheral surface that is shaped in a ring form and is formed such that the side peripheral surface inwardly extends from a bottom surface of the annular groove in a radial direction of a tubular member and is joined to an inner peripheral wall of the tubular member; and a specific shape surface that is formed along at least a part of the side peripheral surface between a bottom surface side end part and an inner peripheral wall side end part of the side peripheral surface such that a diameter of the specific shape surface is progressively reduced in an axial direction of the tubular member from one axial side, at which the bottom surface is placed, toward another axial side, at which the inner peripheral wall is placed.

Abstract: A spool is configured to reciprocate at an inside space of a sleeve and includes: a spool tube; a spool cover, which closes an end portion of the spool tube located on a camshaft side; a pressure accumulation space, which is formed at an inside of the spool tube; a supply passage, which is configured to connect between the pressure accumulation space and a supply port; a control passage, which is configured to connect between the pressure accumulation space and a primary control port; and a control passage, which is configured to connect between the pressure accumulation space and a secondary control port. A variable volume space is formed between the spool cover and a sleeve bottom. The sleeve includes a breathing hole at an outside of the inside space while the breathing hole is a hole that communicates between the variable volume space and the atmosphere.

Abstract: When a supply check valve is opened, the supply check valve enables a flow of oil from an oil supply source toward a pressure accumulation space. When the supply check valve is closed, the supply check valve limits a flow of the oil from the pressure accumulation space toward the oil supply source. When a recycle check valve is opened, the recycle check valve enables a flow of the oil from a retard chamber or an advance chamber toward the pressure accumulation space. When the recycle check valve is closed, the recycle check valve limits a flow of the oil from the pressure accumulation space toward the retard chamber or the advance chamber. A characteristic of the supply check valve with respect to valve opening of the supply check valve is different from a characteristic of the recycle check valve with respect to valve opening of the recycle check valve.

Abstract: A retard supply passage connects between a hydraulic oil supply source and a retard chamber through a hydraulic oil controller. An advance supply passage connects between the hydraulic oil supply source and an advance chamber through the hydraulic oil controller. A drain passage and a drain passage connect the retard chamber and the advance chamber to an oil discharge portion, respectively. A recycle passage connects the drain passage and the drain passage to the retard supply passage and the advance supply passage, respectively. A recycle check valve enables only a flow of hydraulic oil from the drain passages toward the retard supply passage and the advance supply passage in the recycle passage. The recycle passage is connected to the drain passages at an inside of the hydraulic oil controller.

Abstract: A retard supply check valve is installed in a retard supply passage and is located on a side of a hydraulic oil controller where a hydraulic oil supply source is placed. The retard supply check valve enables only a flow of hydraulic oil from the hydraulic oil supply source toward a retard chamber. An advance supply check valve is installed in an advance supply passage and is located on the side of the hydraulic oil controller where the hydraulic oil supply source is placed. The advance supply check valve enables only a flow of the hydraulic oil from the hydraulic oil supply source toward an advance chamber.

Abstract: A supply passage extends through an inner sleeve in a radial direction and conducts hydraulic oil received from a hydraulic oil supply source. An axial passage is located between an outer sleeve and the inner sleeve and extends in an axial direction. The supply passage opens to one end portion of the axial passage while another end portion of the axial passage is configured to connect with a valve timing adjustment device. A supply check valve is installed in the axial passage and is located on a radial side of the supply passage where a radially outer side of the inner sleeve is placed. The supply check valve enables a flow of the hydraulic oil from the supply passage toward the axial passage and limits a flow of the hydraulic oil from the axial passage toward the supply passage.

Abstract: A retard supply passage connects between a hydraulic oil supply source and a retard chamber through a hydraulic oil controller. An advance supply passage connects between the hydraulic oil supply source and an advance chamber through the hydraulic oil controller. A drain passage and a drain passage connect the retard chamber and the advance chamber to an oil discharge portion, respectively. A recycle passage connects the drain passage and the drain passage to the retard supply passage and the advance supply passage, respectively. A recycle check valve enables only a flow of hydraulic oil from the drain passages toward the retard supply passage and the advance supply passage in the recycle passage. The recycle passage is connected to the drain passages at an inside of the hydraulic oil controller.

Abstract: When a supply check valve is opened, the supply check valve enables a flow of oil from an oil supply source toward a pressure accumulation space. When the supply check valve is closed, the supply check valve limits a flow of the oil from the pressure accumulation space toward the oil supply source. When a recycle check valve is opened, the recycle check valve enables a flow of the oil from a retard chamber or an advance chamber toward the pressure accumulation space. When the recycle check valve is closed, the recycle check valve limits a flow of the oil from the pressure accumulation space toward the retard chamber or the advance chamber. A characteristic of the supply check valve with respect to valve opening of the supply check valve is different from a characteristic of the recycle check valve with respect to valve opening of the recycle check valve.

Abstract: A spool is configured to reciprocate at an inside space of a sleeve and includes: a spool tube; a spool cover, which closes an end portion of the spool tube located on a camshaft side; a pressure accumulation space, which is formed at an inside of the spool tube; a supply passage, which is configured to connect between the pressure accumulation space and a supply port; a control passage, which is configured to connect between the pressure accumulation space and a primary control port; and a control passage, which is configured to connect between the pressure accumulation space and a secondary control port. A variable volume space is formed between the spool cover and a sleeve bottom. The sleeve includes a breathing hole at an outside of the inside space while the breathing hole is a hole that communicates between the variable volume space and the atmosphere.

Abstract: A sleeve includes: a supply port communicated with a hydraulic oil supply source; a primary control port communicated with a retard chamber, a secondary control port communicated with an advance chamber; and a drain port communicated with an outside of a valve timing adjustment device. A spool includes: a pressure accumulation space formed at an inside of the spool; a supply passage configured to connect between the pressure accumulation space and the supply port; a primary control passage configured to connect between the pressure accumulation space and the primary control port; a secondary control passage configured to connect between the pressure accumulation space and the secondary control port; and a recycle passage configured to connect between the primary control port or the secondary control port and the pressure accumulation space. The recycle passage and the drain port are connected with each other at the inside of the sleeve.