192 clutches and power-stop control – Vortex-flow drive and clutch – With brake
Patent
1986-05-07
1988-02-02
Bonck, Rodney H.
192 clutches and power-stop control
Vortex-flow drive and clutch
With brake
192 30W, 192 85R, 192103F, F16D 2514
Patent
active
047224266
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to friction clutches and in particular to protection systems which guard against overheating of such clutches due to excessive slippage.
There are many applications where the protection of clutches against damage due to excessive slippage are desirable. One such application is a clutch in a tractor power take-off (PTO) drive line used to connect and disconnect a power take-off (PTO) shaft from the tractor engine.
It is an object of the present invention to provide a clutch protection system to guard against overheating due to excessive slippage which is suitable for the protection of a PTO drive line clutch.
DISCLOSURE OF THE INVENTION
According to the present invention there is provided a clutch protection system to guard against overheating due to excessive slippage in a friction clutch having an engagement means which applies an engagement pressure to the clutch, the system including sensing means to provide signals indicative of the input and output speeds of the clutch; an indicating device which receives a first signal indicative of the clutch input speed and a second signal indicative of either the clutch output speed when the clutch engagement pressure is applied or the clutch input speed when the clutch engagement pressure is not applied, the indicating device having a signal level indicative of the difference between the first and second signals minus a signal indicative of the cooling effect on the clutch due to its own rotation; comparison means for comparing the signal level of the indicating device with a predetermined signal level indicative of a clutch operating condition; and response means responsive to a predetermined comparison result to action a warning device or disingage the clutch.
The operation of the indicating device can be expressed mathematically by stating, for example, that the signal level of the indicating device is proportional to I-S.X (where I is the input speed signal, S is scaling factor which takes account of the cooling effect on the clutch due to its own rotation, and X is the output speed signal when the clutch engagement pressure is applied and the input speed signal when the clutch engagement pressure is not applied) and this signal level is compared in the comparison means with the predetermined signal level.
For example, the comparison means may compare the signal level of the indicating device with first and second predetermined signal levels indicative of different levels of clutch slippage and the response means will action a warning if the signal level of the indicating device exceeds the first predetermined signal level (indicating, for example, that a higher than desirable but still tolerable slippage level exists) and will action a further warning and disengage the clutch if the signal level of the indicating device exceeds the second predetermined signal level (indicating, for example, that slippage has risen to a level above which it cannot be allowed to rise without a serious risk of permanent damage to the clutch).
Determination of the appropriate predetermined signal levels for a given clutch design and/or installation is easily achieved by a system designer who will know (or can determine by testing) the maximum level of slip which the clutch can be subjected to without incurring permanent damage (referred to above as the second predetermined level). The designer can then set his own early warning of potentially dangerous slip levels (the first predetermined level referred to above). This early warning level of slippage could be say half the maximum level of slippage or some other proportion depending both on the inclination of the designer to play safe and also on the clutch design and its installation. For example, as discussed below, the Applicant has found that with a particular tractor PTO drive line clutch installation the second predetermined level could be appropriately set at the signal level reached by the indicating device in two seconds with the clutch fully engaged and with the clutch input ru
REFERENCES:
patent: 4116321 (1978-09-01), Miller
patent: 4348585 (1982-09-01), Hoffman
patent: 4425992 (1984-01-01), Makita
patent: 4428467 (1984-01-01), Hiramatsu
patent: 4457411 (1984-07-01), Hiramatsu
patent: 4488140 (1984-12-01), Lang et al.
patent: 4502579 (1985-03-01), Makita
Regulungstechnische Praxis, vol. 16, No. 11, Nov. 1974, Muenchen, (DE) "Elektronische Uberwachung von Machinenkupplungen", p. 300.
Bonck Rodney H.
Lorence Richard M.
Massey-Ferguson Services N.V.
LandOfFree
Clutch protection system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Clutch protection system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Clutch protection system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1632528