A speed regulation device for the control coupling for driving a turbomachine in order to regulate a machine speed, having: - a calculating element with an algorithm for calculating a coupling temperature (T Km) from supplied, discharged and stored thermal power of the coupling; - a first logic unit with a first comparator (15.1) for comparing the calculated coupling temperature (T Km) with an allowable temperature value (T Kzul) and a first logic (15.2) for specifying a control speed (n LsollTK) depending on the comparison; - an actuator and/or a monitor element for the coupling; characterised in that - the algorithm is configured for determining the coupling temperature for a control coupling whose speed can be constantly changed and which is in the form of a liquid friction coupling which can permanently be operated with slip, and - the calculating element further has: a second logic unit with a second comparator (16.1) for comparing the control speed (n LsollTK) with a set speed (n Lsoll) predetermined by a superior engine cooling control, i.e. a set turbomachine speed, and a second logic for specifying a correction speed (n Lsollkorr) for correcting an actual speed (n List), wherein, on exceeding the allowable temperature value (T Kzul) by the calculated coupling temperature (T Km), the control speed (n LsollTK) can be predeterminable for determining the correction speed (n Lsollkorr) in order to reduce the coupling temperature by the first logic (15.2) and wherein the actuator has: - a regulator (17.1) for an actual speed (n List) corrected by the correction speed (n Lsollkorr) in order to generate an actuating signal under consideration of a mapping value (17.2) triggered by the correction speed (n Lsollkorr) and/or a drive speed (n A). - a calculating element with an algorithm for calculating a coupling temperature (T Km) from supplied, discharged and stored thermal power of the coupling; - a first logic unit with a first comparator (15.1) for comparing the calculated coupling temperature (T Km) with an allowable temperature value (T Kzul) and a first logic (15.2) for specifying a control speed (n LsollTK) depending on the comparison; - an actuator and/or a monitor element for the coupling; - the algorithm is configured for determining the coupling temperature for a control coupling whose speed can be constantly changed and which is in the form of a liquid friction coupling which can permanently be operated with slip, and - the calculating element further has: a second logic unit with a second comparator (16.1) for comparing the control speed (n LsollTK) with a set speed (n Lsoll) predetermined by a superior engine cooling control, i.e. a set turbomachine speed, and a second logic for specifying a correction speed (n Lsollkorr) for correcting an actual speed (n List), wherein, on exceeding the allowable temperature value (T Kzul) by the calculated coupling temperature (T Km), the control speed (n LsollTK) can be predeterminable for determining the correction speed (n Lsollkorr) in order to reduce the coupling temperature by the first logic (15.2) and wherein the actuator has: - a regulator (17.1) for an actual speed (n List) corrected by the correction speed (n Lsollkorr) in order to generate an actuating signal under consideration of a mapping value (17.2) triggered by the correction speed (n Lsollkorr) and/or a drive speed (n A).