Driving unit with adjustable torque

Details Driving unit with adjustable torque Driving unit with adjustable torque

1998-09-13

2000-08-08

Marmor, Charles A.

Planetary gear transmission systems or components

Planetary gearing or element

Coaxial teeth around planet pinion engage axially spaced...

475321, 475265, 475153, F16H 5710

Patent

active

060994339

DESCRIPTION:

BRIEF SUMMARY
The invention relates to a driving unit with a motor and an output shaft driven by the motor, and a transmission device coupled between the motor and the output shaft, which driving supplied to the output shaft having a predetermined maximum value. Within the framework of the present invention, the expression "driving unit" is understood to mean that the motor, the transmission device and the output shaft have been assembled to form an integrated unit.
Such driving units are known per se. The motor is for instance an electromotor, and the transmission device is present to cause the speed of the output shaft to differ from the speed of the motor. As is known, each motor is designed for a specific maximum load. As soon as the momentary load of the output shaft exceeds the torque that can be provided by the motor, the motor will slow down and eventually even come to a standstill. However, such an overload of the motor is injurious to the motor and/or to the different parts of the transmission and/or the use.
Within the framework of the present application, a "slip coupling" is understood to mean a device having at least two parts that are coupled together to transmit a specific force/moment. If the load of those parts is slight, they will behave like a rigid whole and transmit a force or moment virtually without loss. If the load reaches a predetermined value those parts will start slipping relative to each other, so that the force or moment to the transmitted cannot be greater than that predetermined value, which will hereinafter be referred to as "limit value" or "slip value".
In known driving units, a slip coupling is included in the power-transmitting path between the motor and the output shaft, of which slip coupling the limit value is lower than the maximum power of the motor. It is thus provided that the torque supplied to the output shaft cannot exceed a predetermined value defined by the limit value, without the motor coming to a standstill.
U.S. Pat. No. 4,791,833 describes a driving device wherein a pressure-loaded spring operates an overload protection. This pressure-loaded spring is arranged so as to be coaxial to the motor, but is axially in a different position, so that the axial length of the device is relatively great. The adjusting possibilities for the pressing force of the pressure-loaded spring are relatively limited. Further, the construction of this known device are relatively complicated, because fastening members such as screws are required for fixing the different parts together.
U.S. Pat. No. 2,646,375 describes a fairly complicated driving device wherein a pressure-loaded helical spring is arranged at the center of a stator coil, which helical spring exerts a pressing force pressing two rotational output members together. In view of the necessarily slight dimensions of the helical spring, the force that can be exerted thereby is limited. Further, for housing and protecting the device, a housing extending around the motor and transmission members is required.
It is an object of the invention to provide a compact driving unit which can be manufactured and assembled in a simple and hence relatively cheap manner, and of which the above-mentioned limit value can readily and continuously be adjusted.
It is a further object of the invention to provide a driving unit wherein, at constant load on the output shaft, a change of the limit value of the slip coupling does not lead to a change of the axial motor load.
It is a further object of the invention to provide a driving unit wherein the helical spring is of a relatively large design and subjected to a pull, wherein the helical spring also serves to protect the motor and transmnission members.
To that end, the device according to the invention has the features as described in claim 1.
These and other aspects, features and advantages of the present invention will be explained by the following description of a preferred embodiment of a driving unit according to the invention, with reference to the accompanying drawing, wherein:
FIG. 1 is a s

REFERENCES:
patent: 1318568 (1919-10-01), Kittredge
patent: 1413292 (1922-04-01), Rauscher
patent: 3646375 (1972-02-01), Mader
patent: 4155275 (1979-05-01), Devanney
patent: 4614134 (1986-09-01), Bohle
patent: 4791833 (1988-12-01), Sakai et al.
patent: 4834192 (1989-05-01), Hansson
patent: 5385512 (1995-01-01), Moolenaar et al.
patent: 5630771 (1997-05-01), Weber et al.
patent: 5897454 (1999-04-01), Cannaliato

Affiliated with

Also associated with

Rating

Driving unit with adjustable torque does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Driving unit with adjustable torque, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Driving unit with adjustable torque will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1145262