Sumitomo Heavy Industries, Ltd.

Yoshikazu Chiba

Kiyoji Minegishi

Masanori Egawa

Masayuki Tanigawa

Thomas Stapelfeldt

Sepp G Lachenmaier

Hiroyuki Shinoda

In a variable speed geared motor constructed by combining an inverter motor controllable in rotational speed by inverter drive with a gear reducer, the gear reducer is of a two-stage type, and a reduction ratio i of the gear reducer is suppressed so that i.ltoreq.N holds where N stands for a maximum reduction ratio of the inverter motor at which a constant torque characteristic can be ensured. Further, in a series of variable speed geared motors each satisfying the above conditions, a common ratio R of a series of reduction ratios i of the variable speed geared motors is set to 1.2-1.5. For example, the series is set to 2, 3, 4, 5, 6, and 8. Accordingly, the geared motor can be constructed lightly in weight, compactly, and at low costs, and it can be economically used in a rotational speed region of 200-900 rpm which is an ordinary region in driving of a pump or a high-speed conveyor.

Variable speed geared motor and a series thereof

In a motor-equipped reduction gear device with a pre-stage, two covers, which have been indispensable in the past, namely a joint cover and a pre-stage cover, are integrated into a one-body cover (130). Also, the diameter (D1) of the addendum circle of the pinion (110) mounted on the tip of the motor shaft 108 is designed to be smaller than the diameter (D2) of the portion of the motor shaft (108) which extends into the one-body cover (130). This allows the one-body cover (130) to be mounted with the pinion (110) already attached to the tip of the motor shaft (108). The one-body cover (130) can freely and easily be attached to the motor (102) and the gear box (106). As a result, the number of parts is reduced and light weight and compactness are achieved, and accuracy of the center distance and parallelism are improved because cumulative machining errors can be avoided. Furthermore, cost down and improved rigidity are achieved and the number of factors which may cause oil leakage is decreased.

Motor-equipped reduction gear device with a pre-stage

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Ohbu, Japan

Yoshikazu Chiba