Several points of concern I have for you and your situation:
1) In both nursing programs in which I have been a clinical instructor, I am the one solely responsible for my students on the clinical floor. I have had up to 10 students at a time on a unit, so it is definitely a challenge keeping up with all of them. An assigned patient's primary nurse sometimes will elect to help a student with a patient task when I am very busy, but the staff nurses are never expected to do so. It is simply not in their job description. It is, however, in my job description.
2) Can you plan to spend a shift or two on the unit orienting, since you are not familiar with this hospital or the unit? It is almost unsafe for you or your students to be on this unit without this period of orientation. You need to get familiar with the policies and procedures, equipment, protocols, etc. It will give you a chance to get to know some of the staff on the unit as well.
3) I get recommendations for patient assignments for the students in my clinical group from the charge nurse and/or unit case manager the afternoon or evening before my students come to the unit. I thoroughly research each patient assignment the afternoon or evening before our group comes to the unit. I pore through the resident notes, history and physical, nurses notes, respiratory therapy notes, labs, vital signs, I & O, etc., so I feel that I am very familiar with each assigned patient. I then make up my patient assignment grid with information recorded about each patient (diagnosis, code status, allergies, activity level, diet, pertinent lab values, when vital signs are due, special concerns, when medications are due, etc.).
4) The day of my clinical, I always arrive to the unit at least one hour before my students. During this time, I find each nurse taking care of our assigned patients and get a short report/ update for each of the patients on my list. If a patient has been sent home or transferred to another unit, I will then get another patient assignment. I carefully let the nurses know the names of the students who will be taking care of the assigned patients, how long we will be on the unit, if we are giving medications, what tasks we plan to accomplish while on the unit (such as head-to-toe assessments, taking vital signs, I & O, computer charting, etc), which procedures we are allowed to perform (such as inserting NG tubes, discontinuing IVs, giving subcut or IM injections), and which procedures we are not allowed to do (such as hanging chemotherapy, giving IV push narcotics, or changing the settings on a PCA). I also make sure the charge nurse and unit secretary have a list of the students and assigned patients for the particular clinical day. On the list, it is clearly delineated how long we will be on the unit.
5) Does your program have a liaison with the clinical agency, who can discuss the obvious differences in perceptions of your role on the clinical floor and who has primary responsibility to educate your nursing students? Obviously, there is a serious miscommunication that needs to be immediately addressed.
Hope these pointers help. Wishing you the best as you embark upon a new semester on a new unit.