Abstract: A starter includes a motor unit, a drive shaft configured to receive a rotational force of the motor unit and rotate, a transmission pinion gear installed on the drive shaft, an idle shaft extending in a direction parallel to the drive shaft, an idle gear installed on the idle shaft and configured to mesh with the transmission pinion gear, a driving pinion gear installed on the idle shaft and configured to mesh with a ring gear of an engine, a gear cover configured to rotatably support portions of the drive shaft and the idle shaft and accommodate the transmission pinion gear and the idle gear, and a bracket section installed between the motor unit and the gear cover and configured to rotatably support a first end in an axial direction of the idle shaft.

Abstract: An engine starter includes a motor that comprises a drive shaft; and a unidirectional rotation clutch system that is helical-splined to the drive shaft. The clutch system includes a clutch inner; a clutch outer; a clutch roller that is interposed between the clutch outer and the clutch inner; and a spring that urges the clutch roller, wherein a compound film is formed on a surface of the clutch roller or surfaces of the clutch outer and the clutch inner.

Abstract: A starter includes a motor section; an output shaft which rotates with receiving a rotational force of the motor section; a gear mechanism which transmits the rotational force of the output shaft to a ring gear of an engine; and a switch unit which performs electrical connection and disconnection to the motor section. Thus, the output shaft, the gear mechanism and the switch unit are accommodated in a housing, and a groove section for weakening the stiffness of the housing is formed in housing at a position which avoids a position where the switch unit is arranged.

Abstract: A starter includes a motor unit, a drive shaft configured to receive a rotational force of the motor unit and rotate, a transmission pinion gear installed on the drive shaft, an idle shaft extending in a direction parallel to the drive shaft, an idle gear installed on the idle shaft and configured to mesh with the transmission pinion gear, a driving pinion gear installed on the idle shaft and configured to mesh with a ring gear of an engine, a gear cover configured to rotatably support portions of the drive shaft and the idle shaft and accommodate the transmission pinion gear and the idle gear, and a bracket section installed between the motor unit and the gear cover and configured to rotatably support a first end in an axial direction of the idle shaft.

Abstract: Excellent durability can be achieved by reducing thermal influences of the excessive load from the engine side for a clutch roller (13) in a unidirectional rotation clutch system that is helical-splined to a drive shaft that rotates in response to a driving force of a motor and structured such that the motor driving force can be transmitted while an engine driving force cannot be transmitted when an engine stars, wherein a compound film composed of an external mixed phase and an internal diffused phase is formed on the clutch roller (13) subjected to nitriding by tufftriding with nitrogen being penetrating and diffusing.

Abstract: A starter includes a motor section; an output shaft which rotates with receiving a rotational force of the motor section; a gear mechanism which transmits the rotational force of the output shaft to a ring gear of an engine; and a switch unit which performs electrical connection and disconnection to the motor section. Thus, the output shaft, the gear mechanism and the switch unit are accommodated in a housing, and a groove section for weakening the stiffness of the housing is formed in housing at a position which avoids a position where the switch unit is arranged.

Abstract: A screw mounting hole and a female screw part are formed in a bearing part of a gear cover, and the screw insertion hole is formed in the idle shaft. The idle shaft is fixed to the gear cover by inserting a fixing screw through the screw mounting hole and screwing it into the female screw part through the screw insertion hole. A positioning groove in a predetermined position in relation to the screw insertion hole is formed in the end face of the idle shaft. When the positioning groove is disposed perpendicularly to an engine mounting surface and the idle shaft is fitted to the gear cover, the screw mounting hole is opposed to the screw insertion hole and, when the fixing screw is fitted, the confirmation of hole positions and the aligning of holes can be eliminated.

Abstract: Excellent durability can be achieved by reducing thermal influences of the excessive load from the engine side for a clutch roller (13) in a unidirectional rotation clutch system that is helical-splined to a drive shaft that rotates in response to a driving force of a motor and structured such that the motor driving force can be transmitted while an engine driving force cannot be transmitted when an engine stars, wherein a compound film composed of an external mixed phase and an internal diffused phase is formed on the clutch roller (13) subjected to nitriding by tufftriding with nitrogen being penetrating and diffusing.

Abstract: An engine starter includes a motor that comprises a drive shaft; and a unidirectional rotation clutch system that is helical-splined to the drive shaft. The clutch system includes a clutch inner; a clutch outer; a clutch roller that is interposed between the clutch outer and the clutch inner; and a spring that urges the clutch roller, wherein a compound film is formed on a surface of the clutch roller or surfaces of the clutch outer and the clutch inner.

Abstract: A helical spline section 61 is formed on a drive shaft 32 rotated by a motor 11 via a planetary gear mechanism 12, and an axially movable overrunning clutch 13 is mounted to the helical spline section 61. A clutch inner 57 of the overrunning clutch 13 is formed integrally with a pinion 14, and the pinion 14 engages with an idle gear 15. Between the idle gear 15 and the clutch cover 68 of the overrunning clutch 13, there is provided a synthetic resin slip plate 95. The slip plate 95 is provided with slide-contact surfaces 95a and 95b coming into contact with the idle gear 15 and the clutch cover 68. On each of the slide-contact surfaces 95a and 95b, there is provided concavely an annular grease reservoir 96 holding grease on each of the slide-contact surfaces. Thereby, the lubricating ability of a spacer provided between the slide-contact members having mutually different rotation numbers is improved, resulting in reducing the cost of materials and preventing the burn-in between the members.

Abstract: [PROBLEMS] To provide a starter motor enabling the easy and accurate aligning of holes when an idle shaft is mounted. [MEANS FOR SOLVING THE PROBLEMS] The screw mounting hole (106) and a female screw part (105) are formed in the bearing part (98) of a gear cover (24) and the screw insertion hole (104) is formed in the idle shaft (89). The idle shaft (89) is fixed to the gear cover (24) by inserting a fixing screw (107) through the screw mounting hole (106) and screwing it into the female screw part (105) through the screw insertion hole (104). A positioning groove (108) in a predetermined position relation with the screw insertion hole (104) is formed in the end face of the idle shaft (89).

Abstract: A helical spline section 61 is formed on a drive shaft 32 rotated by a motor 11 via a planetary gear mechanism 12, and an axially movable overrunning clutch 13 is mounted to the helical spline section 61. A pinion 14 engaging with an idle gear 15 is formed integrally with a clutch inner 57 of the overrunning clutch 13. At the distal end of the pinion 14, there is formed a transport flange 72 engaging with the idle gear 15 and disengaging the idle gear 15 from a ring gear 16 together with the axial movement of the pinion 14. The root outer diameter of a gear section 71 of the pinion 14 is smaller than the outer diameter of the clutch inner 57, and the pinion 14 is formed integrally with the transport flange 72 and the clutch inner 57 by cold forging. Thereby, there is provided a simple, cheap and reliable electric starter motor capable of engaging and disengaging the idle gear and ring gear with each other and from each other without increasing the number of parts.

Abstract: An engine starter includes a unidirectional rotation clutch system with a clutch outer having an outer-diameter side cylinder portion, a clutch inner having an inner-diameter side cylinder portion, long shaft-shaped clutch rollers that are long in a drive shaft direction and are installed in wedge spaces formed between the inner and outer-diameter side cylinder portions, and springs that urge the clutch rollers toward wedge portions, wherein at least one of the inner and outer-diameter side cylinder portions includes a wear preventive portion that prevents wearing of the clutch rollers that have turned so as to be in an inclined posture with respect to the drive shaft.